High-latitude steppe vegetation and the mineral nutrition of Pleistocene herbivores

Science.gov (United States)

Davydov, S. P.; Davydova, A.; Makarevich, R.; Loranty, M. M.; Boeskorov, G.

2014-12-01

High-latitude steppes were widespread and zonal in the Late Pleistocene and formed a landscape basis for the Mammoth Biome. Now the patches of these steppes survived on steep slopes under southern aspects. These steppes serve as unique information sources about the Late Pleistocene "Mammoth" steppe. Numerous data obtained by palynological, carpological, and DNA analysis of plant remains from feces and stomach contents of Pleistocene herbivore mummies, as well as from buried soils and enclosing deposits show that they are similar to modern steppe plant assemblage in taxa composition. Plant's nutrient concentrations are of fundamental importance across Pleistocene grass-rich ecosystems because of their role in the support of large herbivores. The average weight of an adult mammoth skeleton (about 0.5 tons) and of a woolly rhinoceros (about 0.2 tons) clearly suggests this. Detailed studies on fossil bone remains showed mineral deficiency in large Pleistocene herbivores. A three-year study of ash and mineral contents of two types of relict steppe vegetation at the Kolyma Lowland, Arctic Siberia has been carried out. Nowadays refugia of similar vegetation are located not far (1 - 15km) from the Yedoma permafrost outcrops were abundant fossil remains are found. Dominant species of the steppe vegetation were sampled. Preliminary studies indicate that the ash-content varied 1.5-2 times in speceies of steppe herbs. The Ca, P, Mg, K element contents was higher for most steppe species than in the local herbaceous vegetation, especially in Ca and P. One of the most important elements of the mineral nutrition, the phosphorus, was always found in higher concentrations in the steppe vegetation than in plants of recently dominant landscapes of the study area. It should be noted that the mineral nutrient content of the modern steppe vegetation of Siberian Arctic is comparable to that of the recent zonal steppe of Transbaikal Region. This study supports the hypothesis that

Current ecosystem processes in steppe near Lake Baikal

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Vanteeva, Julia

2015-04-01

herbaceous phytomass of the steppe complexes varied from 0.4 to 2.64 t/ha. Apical stony and sloping grass-forb landscapes and areas of settlements and recreation facilities had the lowest values. Forest steppes were characterized by low crown density, non-large stand density, which was represented mainly by larch. Phytomass stock ranged from 30.78 to 282.24 t/ha. Maximum values corresponded to the forest steppe with larch on steep slopes. The maximum values of the silt matter transfer (up to 124 g /m2) corresponded to areas with a strong recreation pressure with the lower value of vegetation cover (from 0 to 45%) and aboveground herbaceous phytomass (0.4 - 0.6 t/ha). During experiment with using rainfall simulator defined different sensibility to soil erosion, for example, for Caragana steppe with sagebrush on the undisturbed area trapped silt is 12 g/m2 and for anthropogenic disturbed patch - 84 g/m2. For Sagebrush steppe trapped silt changed from 4 to 16 g/m2. The study shows strong landscapes transformation leading to loss of biodiversity, the reduction of phytomass production and water percolation.

Multiscale sagebrush rangeland habitat modeling in the Gunnison Basin of Colorado

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Homer, Collin G.; Aldridge, Cameron L.; Meyer, Debra K.; Schell, Spencer J.

2013-01-01

North American sagebrush-steppe ecosystems have decreased by about 50 percent since European settlement. As a result, sagebrush-steppe dependent species, such as the Gunnison sage-grouse, have experienced drastic range contractions and population declines. Coordinated ecosystem-wide research, integrated with monitoring and management activities, is needed to help maintain existing sagebrush habitats; however, products that accurately model and map sagebrush habitats in detail over the Gunnison Basin in Colorado are still unavailable. The goal of this project is to provide a rigorous large-area sagebrush habitat classification and inventory with statistically validated products and estimates of precision across the Gunnison Basin. This research employs a combination of methods, including (1) modeling sagebrush rangeland as a series of independent objective components that can be combined and customized by any user at multiple spatial scales; (2) collecting ground measured plot data on 2.4-meter QuickBird satellite imagery in the same season the imagery is acquired; (3) modeling of ground measured data on 2.4-meter imagery to maximize subsequent extrapolation; (4) acquiring multiple seasons (spring, summer, and fall) of Landsat Thematic Mapper imagery (30-meter) for optimal modeling; (5) using regression tree classification technology that optimizes data mining of multiple image dates, ratios, and bands with ancillary data to extrapolate ground training data to coarser resolution Landsat Thematic Mapper; and 6) employing accuracy assessment of model predictions to enable users to understand their dependencies. Results include the prediction of four primary components including percent bare ground, percent herbaceous, percent shrub, and percent litter, and four secondary components including percent sagebrush (Artemisia spp.), percent big sagebrush (Artemisia tridentata), percent Wyoming sagebrush (Artemisia tridentata wyomingensis), and shrub height (centimeters

Projecting the Dependence of Sage-steppe Vegetation on Redistributed Snow in a Warming Climate.

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Soderquist, B.; Kavanagh, K.; Link, T. E.; Seyfried, M. S.; Strand, E. K.

2015-12-01

In mountainous regions, the redistribution of snow by wind can increase the effective precipitation available to vegetation. Moisture subsidies caused by drifting snow may be critical to plant productivity in semi-arid ecosystems. However, with increasing temperatures, the distribution of precipitation is becoming more uniform as rain replaces drifting snow. Understanding the ecohydrological interactions between sagebrush steppe vegetation communities and the heterogeneous distribution of soil moisture is essential for predicting and mitigating future losses in ecosystem diversity and productivity in regions characterized by snow dominated precipitation regimes. To address the dependence of vegetation productivity on redistributed snow, we simulated the net primary production (NPP) of aspen, sagebrush, and C3 grass plant functional types spanning a precipitation phase (rain:snow) gradient in the Reynolds Creek Experimental Watershed and Critical Zone Observatory (RCEW-CZO). The biogeochemical process model Biome-BGC was used to simulate NPP at three sites located directly below snowdrifts that provide melt water late into the spring. To assess climate change impacts on future plant productivity, mid-century (2046-2065) NPP was simulated using the average temperature increase from the Multivariate Adaptive Constructed Analogs (MACA) data set under the RCP 8.5 emission scenario. At the driest site, mid-century projections of decreased snow cover and increased growing season evaporative demand resulted in limiting soil moisture up to 30 and 40 days earlier for aspen and sage respectively. While spring green up for aspen occurred an average of 13 days earlier under climate change scenarios, NPP remained negative up to 40 days longer during the growing season. These results indicate that the loss of the soil moisture subsidy stemming from prolonged redistributed snow water resources can directly influence ecosystem productivity in the rain:snow transition zone.

Calibration of remotely sensed, coarse resolution NDVI to CO2 fluxes in a sagebrush-steppe ecosystem

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Wylie, B.K.; Johnson, D.A.; Laca, Emilio; Saliendra, Nicanor Z.; Gilmanov, T.G.; Reed, B.C.; Tieszen, L.L.; Worstell, B.B.

2003-01-01

The net ecosystem exchange (NEE) of carbon flux can be partitioned into gross primary productivity (GPP) and respiration (R). The contribution of remote sensing and modeling holds the potential to predict these components and map them spatially and temporally. This has obvious utility to quantify carbon sink and source relationships and to identify improved land management strategies for optimizing carbon sequestration. The objective of our study was to evaluate prediction of 14-day average daytime CO2 fluxes (Fday) and nighttime CO2 fluxes (Rn) using remote sensing and other data. Fday and Rn were measured with a Bowen ratio-energy balance (BREB) technique in a sagebrush (Artemisia spp.)-steppe ecosystem in northeast Idaho, USA, during 1996-1999. Micrometeorological variables aggregated across 14-day periods and time-integrated Advanced Very High Resolution Radiometer (AVHRR) Normalized Difference Vegetation Index (iNDVI) were determined during four growing seasons (1996-1999) and used to predict Fday and Rn. We found that iNDVI was a strong predictor of Fday (R2 = 0.79, n = 66, P improved predictions of Fday (R2= 0.82, n = 66, P management strategies, carbon certification, and validation and calibration of carbon flux models. ?? 2003 Elsevier Science Inc. All rights reserved.

Selection of anthropogenic features and vegetation characteristics by nesting Common Ravens in the sagebrush ecosystem

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Howe, Kristy B.; Coates, Peter S.; Delehanty, David J.

2014-01-01

Common Raven (Corvus corax) numbers and distribution are increasing throughout the sagebrush steppe, influencing avian communities in complex ways. Anthropogenic structures are thought to increase raven populations by providing food and nesting subsidies, which is cause for concern because ravens are important nest predators of sensitive species, including Greater Sage-Grouse (Centrocercus urophasianus). During 2007–2009, we located raven nests in southeastern Idaho and conducted a resource selection analysis. We measured variables at multiple spatial scales for 72 unique nest locations, including landscape-level vegetation characteristics and anthropogenic structures. Using generalized linear mixed models and an information-theoretic approach, we found a 31% decrease in the odds of nesting by ravens for every 1 km increase in distance away from a transmission line. Furthermore, a 100-m increase in distance away from the edge of two different land cover types decreased the odds of nesting by 20%, and an increase in the amount of edge by 1 km within an area of 102.1 ha centered on the nest increased the odds of nesting by 49%. A post hoc analysis revealed that ravens were most likely to nest near edges of adjoining big sagebrush (Artemisia tridentata) and land cover types that were associated with direct human disturbance or fire. These findings contribute to our understanding of raven expansion into rural environments and could be used to make better-informed conservation decisions, especially in the face of increasing renewable energy development.

Ecohydrology of adjacent sagebrush and lodgepole pine ecosystems: the consequences of climate change and disturbance

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Bradford, John B.; Schlaepfer, Daniel R.; Lauenroth, William K.

2014-01-01

Sagebrush steppe and lodgepole pine forests are two of the most widespread vegetation types in the western United States and they play crucial roles in the hydrologic cycle of these water-limited regions. We used a process-based ecosystem water model to characterize the potential impact of climate change and disturbance (wildfire and beetle mortality) on water cycling in adjacent sagebrush and lodgepole pine ecosystems. Despite similar climatic and topographic conditions between these ecosystems at the sites examined, lodgepole pine, and sagebrush exhibited consistent differences in water balance, notably more evaporation and drier summer soils in the sagebrush and greater transpiration and less water yield in lodgepole pine. Canopy disturbances (either fire or beetle) have dramatic impacts on water balance and availability: reducing transpiration while increasing evaporation and water yield. Results suggest that climate change may reduce snowpack, increase evaporation and transpiration, and lengthen the duration of dry soil conditions in the summer, but may have uncertain effects on drainage. Changes in the distribution of sagebrush and lodgepole pine ecosystems as a consequence of climate change and/or altered disturbance regimes will likely alter ecosystem water balance.

Wyoming big sagebrush: Efforts towards development of target plants for restoration

Science.gov (United States)

Kayla R. Herriman

2009-01-01

Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis) is a dominant shrub throughout much of the interior western United States. It is a key component of sagebrush steppe ecosystems, which have been degraded due to European settlement, improper land use, and changing fire regimes resulting from the invasion of exotic...

Influence of container size on Wyoming big sagebrush seedling morphology and cold hardiness

Science.gov (United States)

Kayla R. Herriman; Anthony S. Davis; R. Kasten Dumroese

2009-01-01

Wyoming big sagebrush (Artemisia tridentata) is a key component of sagebrush steppe ecosystems and is a dominant shrub throughout the western United States. Our objective was to identify the effect of container size on plant morphology of Wyoming big sagebrush. We used three different stocktypes (45/340 ml [20 in3], 60/250 ml [15 in3], 112/105 ml [6....

Attempting to restore herbaceous understories in Wyoming big sagebrush communities with mowing and seeding

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Shrub steppe communities with depleted perennial herbaceous understories need to be restored to increase resilience, provide quality wildlife habitat, and improve ecosystem function. Mowing has been applied to Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle &Young) steppe...

The economics of fuel management: Wildfire, invasive plants, and the dynamics of sagebrush rangelands in the western United States

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Michael H. Taylor; Kimberly Rollins; Mimako Kobayashi; Robin J. Tausch

2013-01-01

In this article we develop a simulation model to evaluate the economic efficiency of fuel treatments and apply it to two sagebrush ecosystems in the Great Basin of the western United States: the Wyoming Sagebrush Steppe and Mountain Big Sagebrush ecosystems. These ecosystems face the two most prominent concerns in sagebrush ecosystems relative to wildfire: annual grass...

Plant litter effects on soil nutrient availability and vegetation dynamics: changes that occur when annual grasses invade shrub-steppe communities

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Sheel Bansal; Roger L. Sheley; Bob Blank; Edward A. Vasquez

2014-01-01

Changes in the quantity and quality of plant litter occur in many ecosystems as they are invaded by exotic species, which impact soil nutrient cycling and plant community composition. Such changes in sagebrush-steppe communities are occurring with invasion of annual grasses (AG) into a perennial grass (PG) dominated system. We conducted a 5-year litter manipulation...

Multiscale sagebrush rangeland habitat modeling in southwest Wyoming

Science.gov (United States)

Homer, Collin G.; Aldridge, Cameron L.; Meyer, Debra K.; Coan, Michael J.; Bowen, Zachary H.

2009-01-01

Sagebrush-steppe ecosystems in North America have experienced dramatic elimination and degradation since European settlement. As a result, sagebrush-steppe dependent species have experienced drastic range contractions and population declines. Coordinated ecosystem-wide research, integrated with monitoring and management activities, would improve the ability to maintain existing sagebrush habitats. However, current data only identify resource availability locally, with rigorous spatial tools and models that accurately model and map sagebrush habitats over large areas still unavailable. Here we report on an effort to produce a rigorous large-area sagebrush-habitat classification and inventory with statistically validated products and estimates of precision in the State of Wyoming. This research employs a combination of significant new tools, including (1) modeling sagebrush rangeland as a series of independent continuous field components that can be combined and customized by any user at multiple spatial scales; (2) collecting ground-measured plot data on 2.4-meter imagery in the same season the satellite imagery is acquired; (3) effective modeling of ground-measured data on 2.4-meter imagery to maximize subsequent extrapolation; (4) acquiring multiple seasons (spring, summer, and fall) of an additional two spatial scales of imagery (30 meter and 56 meter) for optimal large-area modeling; (5) using regression tree classification technology that optimizes data mining of multiple image dates, ratios, and bands with ancillary data to extrapolate ground training data to coarser resolution sensors; and (6) employing rigorous accuracy assessment of model predictions to enable users to understand the inherent uncertainties. First-phase results modeled eight rangeland components (four primary targets and four secondary targets) as continuous field predictions. The primary targets included percent bare ground, percent herbaceousness, percent shrub, and percent litter. The

Resilience and resistance of sagebrush ecosystems: implications for state and transition models and management treatments

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Chambers, Jeanne C.; Miller, Richard F.; Board, David I.; Pyke, David A.; Roundy, Bruce A.; Grace, James B.; Schupp, Eugene W.; Tausch, Robin J.

2014-01-01

In sagebrush ecosystems invasion of annual exotics and expansion of piñon (Pinus monophylla Torr. and Frem.) and juniper (Juniperus occidentalis Hook., J. osteosperma [Torr.] Little) are altering fire regimes and resulting in large-scale ecosystem transformations. Management treatments aim to increase resilience to disturbance and enhance resistance to invasive species by reducing woody fuels and increasing native perennial herbaceous species. We used Sagebrush Steppe Treatment Evaluation Project data to test predictions on effects of fire vs. mechanical treatments on resilience and resistance for three site types exhibiting cheatgrass (Bromus tectorum L.) invasion and/or piñon and juniper expansion: 1) warm and dry Wyoming big sagebrush (WY shrub); 2) warm and moist Wyoming big sagebrush (WY PJ); and 3) cool and moist mountain big sagebrush (Mtn PJ). Warm and dry (mesic/aridic) WY shrub sites had lower resilience to fire (less shrub recruitment and native perennial herbaceous response) than cooler and moister (frigid/xeric) WY PJ and Mtn PJ sites. Warm (mesic) WY Shrub and WY PJ sites had lower resistance to annual exotics than cool (frigid to cool frigid) Mtn PJ sites. In WY shrub, fire and sagebrush mowing had similar effects on shrub cover and, thus, on perennial native herbaceous and exotic cover. In WY PJ and Mtn PJ, effects were greater for fire than cut-and-leave treatments and with high tree cover in general because most woody vegetation was removed increasing resources for other functional groups. In WY shrub, about 20% pretreatment perennial native herb cover was necessary to prevent increases in exotics after treatment. Cooler and moister WY PJ and especially Mtn PJ were more resistant to annual exotics, but perennial native herb cover was still required for site recovery. We use our results to develop state and transition models that illustrate how resilience and resistance influence vegetation dynamics and management options.

Eurasian perspectives on the role of kurgans in the conservation and restoration of steppe vegetation

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Deák, Balázs; Valkó, Orsolya; Török, Péter; Sudnik-Wójcikowska, Barbara; Moysiyenko, Ivan; Bragina, Tatyana; Apostolova, Iva; Dembicz, Iwona; Bykov, Nikolai; Tóthmérész, Béla

2017-04-01

Steppe is among the most endangered biomes of the world, especially in Europe, where more than 90% of original steppes have been destroyed due to conversion into croplands, afforestation and other human activities. Because of the socio-economic changes of the past centuries, steppe vegetation is now often restricted to places inadequate for ploughing, such as ancient burial mounds called kurgans. Thus, beside that kurgans are millennia-old iconic historical monuments of the steppic landscape, they are vital in preserving both our cultural and natural heritage. We collected and synthesised existing knowledge on kurgans by a review of research papers and grey literature and provided recommendations for elaborating the involvement of kurgans into agri-environmental schemes. We found that the proportions of kurgans covered by steppe vegetation increase from west to east and from lowlands to uplands. Despite their small size, kurgans act as biodiversity hotspots and harbour many red-listed plant species. High biodiversity is maintained by a pronounced fine-scale environmental heterogeneity provided by the special micro-topography of the kurgans. We found that landscape-level land use changes such as intensified agriculture and construction works are the major threatening factors for biodiversity of kurgans. Despite the vital role of kurgans in sustaining steppe vegetation, we identified serious knowledge gaps on their distribution, vegetation, flora and fauna and their potential role in steppe restoration. We conclude that these sacral places play a crucial role in preserving steppe vegetation, especially in intensively used agricultural landscapes in the western part of the steppe zone. They maintain ecosystem functions at the landscape-level by providing refugia for rare grassland specialist species and ensuring habitat connectivity in anthropogenic landscapes. Based on our results we suggest improving existing agri-environmental schemes which only focus on the

Genetic and environmental effects on seed weight in subspecies of big sagebrush: Applications for restoration

Science.gov (United States)

Bryce A. Richardson; Hector G. Ortiz; Stephanie L. Carlson; Deidre M. Jaeger; Nancy L. Shaw

2015-01-01

The sagebrush steppe is a patchwork of species and subspecies occupying distinct environmental niches across the intermountain regions of western North America. These ecosystems face degradation from disturbances and exotic weeds. Using sagebrush seed that is matched to its appropriate niche is a critical component to successful restoration, improving habitat for the...

Characterization of a sagebrush (Artemisia tridentata ssp. wyomingensis) die-off on the Handford Site

International Nuclear Information System (INIS)

Cardenas, A.; Lewinsohn, J.; Auger, C.; Downs, J.L.; Cadwell, L.L.; Burrows, R.

1997-09-01

The Hanford Site contains one of the few remaining contiguous areas of shrub-steppe habitat left in Washington State. This habitat is home to many native plant and wildlife species, some of which are threatened with extinction or are unique to the Site. The importance of the Hanford Site increases as other lands surrounding the Site are developed, and these native species and habitats are lost. Stands of Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) on the Site are a particularly important component of shrub-steppe habitat, because a number of wildlife require big sagebrush for food and cover. Since 1993, researchers and field biologists have made anecdotal observations of dying and declining sagebrush in stands of shrubs near the 100 Areas. This study was initiated to delineate and document the general boundary where sagebrush stands appear to be declining. We mapped the areal extent of the die-off using a global positioning system and found that the central portion of the die-off encompasses 280 hectares. Shrub stand defoliation was estimated to be near or greater than 80% in this area. The remainder of the die-off area exhibits varying mixtures of completely defoliated, partially defoliated, and healthy-looking stands. Declining sagebrush stands comprise a total of 1776 hectares

Characterization of a sagebrush (Artemisia tridentata ssp. wyomingensis) die-off on the Handford Site

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Cardenas, A.; Lewinsohn, J.; Auger, C.; Downs, J.L.; Cadwell, L.L.; Burrows, R.

1997-09-01

The Hanford Site contains one of the few remaining contiguous areas of shrub-steppe habitat left in Washington State. This habitat is home to many native plant and wildlife species, some of which are threatened with extinction or are unique to the Site. The importance of the Hanford Site increases as other lands surrounding the Site are developed, and these native species and habitats are lost. Stands of Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) on the Site are a particularly important component of shrub-steppe habitat, because a number of wildlife require big sagebrush for food and cover. Since 1993, researchers and field biologists have made anecdotal observations of dying and declining sagebrush in stands of shrubs near the 100 Areas. This study was initiated to delineate and document the general boundary where sagebrush stands appear to be declining. We mapped the areal extent of the die-off using a global positioning system and found that the central portion of the die-off encompasses 280 hectares. Shrub stand defoliation was estimated to be near or greater than 80% in this area. The remainder of the die-off area exhibits varying mixtures of completely defoliated, partially defoliated, and healthy-looking stands. Declining sagebrush stands comprise a total of 1776 hectares.

2004 annual progress report: Stratton Sagebrush Hydrology Study Area: Establishment of a long-term research site in a high-elevation sagebrush steppe

Science.gov (United States)

Schoenecker, Kate; Lange, Bob; Calton, Mike

2005-01-01

In 2004 the U.S. Geological Survey, Fort Collins Science Center (FORT) and the Bureau of Land Management (BLM), Rawlins Field Office (RFO), began a cooperative effort to reestablish the Stratton Sagebrush Hydrology Study Area (Stratton) as a research location, with the goal of making it a site for long-term research on sagebrush (Artemisia spp.) ecology. No other long-term research sites in high-elevation sagebrush habitat currently exist, and the Stratton area, with its 30+ year history of research and baseline data, was a logical location to restart investigations aimed at answering pertinent and timely questions about sagebrush ecology and sagebrush-obligate species. During the first year of the study, USGS scientists conducted an in-depth literature search to locate publications from research conducted at Stratton. We contacted previous researchers to acquire literature and unpublished reports of work conducted at Stratton. Collated papers and published manuscripts were presented in an annotated bibliography (Burgess and Schoenecker, 2004).

Prescribed Fire Effects on Runoff, Erosion, and Soil Water Repellency on Steeply-Sloped Sagebrush Rangeland over a Five Year Period

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Williams, C. J.; Pierson, F. B.; Al-Hamdan, O. Z.

2014-12-01

Fire is an inherent component of sagebrush steppe rangelands in western North America and can dramatically affect runoff and erosion processes. Post-fire flooding and erosion events pose substantial threats to proximal resources, property, and human life. Yet, prescribed fire can serve as a tool to manage vegetation and fuels on sagebrush rangelands and to reduce the potential for large catastrophic fires and mass erosion events. The impact of burning on event hydrologic and erosion responses is strongly related to the degree to which burning alters vegetation, ground cover, and surface soils and the intensity and duration of precipitation. Fire impacts on hydrologic and erosion response may be intensified or reduced by inherent site characteristics such as topography and soil properties. Parameterization of these diverse conditions in predictive tools is often limited by a lack of data and/or understanding for the domain of interest. Furthermore, hydrologic and erosion functioning change as vegetation and ground cover recover in the years following burning and few studies track these changes over time. In this study, we evaluated the impacts of prescribed fire on vegetation, ground cover, soil water repellency, and hydrologic and erosion responses 1, 2, and 5 yr following burning of a mountain big sagebrush community on steep hillslopes with fine-textured soils. The study site is within the Reynolds Creek Experimental Watershed, southwestern Idaho, USA. Vegetation, ground cover, and soil properties were measured over plot scales of 0.5 m2 to 9 m2. Rainfall simulations (0.5 m2) were used to assess the impacts of fire on soil water repellency, infiltration, runoff generation, and splash-sheet erosion. Overland flow experiments (9 m2) were used to assess the effects of fire-reduced ground cover on concentrated-flow runoff and erosion processes. The study results provide insight regarding fire impacts on runoff, erosion, and soil water repellency in the immediate and

Ecosystem functional response across precipitation extremes in a sagebrush steppe.

Science.gov (United States)

Tredennick, Andrew T; Kleinhesselink, Andrew R; Taylor, J Bret; Adler, Peter B

2018-01-01

Precipitation is predicted to become more variable in the western United States, meaning years of above and below average precipitation will become more common. Periods of extreme precipitation are major drivers of interannual variability in ecosystem functioning in water limited communities, but how ecosystems respond to these extremes over the long-term may shift with precipitation means and variances. Long-term changes in ecosystem functional response could reflect compensatory changes in species composition or species reaching physiological thresholds at extreme precipitation levels. We conducted a five year precipitation manipulation experiment in a sagebrush steppe ecosystem in Idaho, United States. We used drought and irrigation treatments (approximately 50% decrease/increase) to investigate whether ecosystem functional response remains consistent under sustained high or low precipitation. We recorded data on aboveground net primary productivity (ANPP), species abundance, and soil moisture. We fit a generalized linear mixed effects model to determine if the relationship between ANPP and soil moisture differed among treatments. We used nonmetric multidimensional scaling to quantify community composition over the five years. Ecosystem functional response, defined as the relationship between soil moisture and ANPP, was similar among irrigation and control treatments, but the drought treatment had a greater slope than the control treatment. However, all estimates for the effect of soil moisture on ANPP overlapped zero, indicating the relationship is weak and uncertain regardless of treatment. There was also large spatial variation in ANPP within-years, which contributes to the uncertainty of the soil moisture effect. Plant community composition was remarkably stable over the course of the experiment and did not differ among treatments. Despite some evidence that ecosystem functional response became more sensitive under sustained drought conditions, the response

Carbon dioxide effluxes and their environmental controls in sagebrush steppe ecosystems along an elevation gradient in the Reynolds Creek Critical Zone Observatory

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Lohse, K. A.; Fellows, A.; Flerchinger, G. N.; Seyfried, M. S.

2017-12-01

The spatial and temporal variation of carbon dioxide effluxes and their environmental controls are poorly constrained in cold shrub steppe ecosystems. The objectives of this study were to 1) analyze environmental parameters in determining soil CO2 efflux, 2) assess the level of agreement between manual chambers and force diffusion (FD) soil CO2 efflux chambers, when both measurements are extrapolated across the growing season, and lastly to compare respiration fluxes to modeled ecosystem respiration fluxes. We installed FD chambers at four sites co-located with eddy covariance (EC) towers and soil moisture and temperature sensors along an elevation gradient in the Reynolds Creek Critical Zone Observatory in SW Idaho. FD chamber fluxes were collected continuously at 15-minute intervals. We sampled soil CO2 efflux with manual chambers at plant and interplant spaces in five plots at each site biweekly to monthly during the growing season. The sites included a Wyoming big sagebrush site, a low sagebrush site, a post-fire mountain big sagebrush site, and a mountain big sagebrush site located at elevations of 1425, 1680, 1808 and 2111 m. Climate variation followed the montane elevation gradient; mean annual precipitation (MAP) at the sites is 290, 337, 425, and 795 mm, respectively, and mean annual temperature is 8.9, 8.4, 6.1, 5.4°C. Automated force diffusion chambers detected large differences in carbon dioxide pulse dynamics along the elevation gradient. Growing season carbon dioxide fluxes were 3 times higher at the 425 mm MAP site compared than the lowest elevation sites at 290 and 337 MAP sites and >1.5 higher than the 795 mm MAP site over the same period. Manual fluxes showed similar seasonal patterns as FD chamber fluxes but often higher and greater spatial variability in fluxes than FD chamber fluxes. Plant and interplant flux differences were surprisingly similar, especially at higher elevations. Soil respiration ranged from 0.2-0.48 of ecosystem respiration

Aeolian nutrient fluxes following wildfire in sagebrush steppe: implications for soil carbon storage

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N. J. Hasselquist

2011-12-01

Full Text Available Pulses of aeolian transport following fire can profoundly affect the biogeochemical cycling of nutrients in semi-arid and arid ecosystems. Our objective was to determine horizontal nutrient fluxes occurring in the saltation zone during an episodic pulse of aeolian transport that occurred following a wildfire in a semi-arid sagebrush steppe ecosystem in southern Idaho, USA. We also examined how temporal trends in nutrient fluxes were affected by changes in particle sizes of eroded mass as well as nutrient concentrations associated with different particle size classes. In the burned area, total carbon (C and nitrogen (N fluxes were as high as 235 g C m⁻¹ d⁻¹ and 19 g N m⁻¹ d⁻¹ during the first few months following fire, whereas C and N fluxes were negligible in an adjacent unburned area throughout the study. Temporal variation in C and N fluxes following fire was largely attributable to the redistribution of saltation-sized particles. Total N and organic C concentrations in the soil surface were significantly lower in the burned relative to the unburned area one year after fire. Our results show how an episodic pulse of aeolian transport following fire can affect the spatial distribution of soil C and N, which, in turn, can have important implications for soil C storage. These findings demonstrate how an ecological disturbance can exacerbate a geomorphic process and highlight the need for further research to better understand the role aeolian transport plays in the biogeochemical cycling of C and N in recently burned landscapes.

Vegetation monitoring to detect and predict vegetation change: Connecting historical and future shrub/steppe data in Yellowstone National Park

Science.gov (United States)

Geneva Chong; David Barnett; Benjamin Chemel; Roy Renkin; Pamela Sikkink

2011-01-01

A 2002 National Research Council (NRC) evaluation of ungulate management practices in Yellowstone specifically concluded that previous (1957 to present) vegetation monitoring efforts were insufficient to determine whether climate or ungulates were more influential on shrub/steppe dynamics on the northern ungulate winter range. The NRC further recommended that the...

Indicators of ecosystem function identify alternate states in the sagebrush steppe.

Science.gov (United States)

Kachergis, Emily; Rocca, Monique E; Fernandez-Gimenez, Maria E

2011-10-01

Models of ecosystem change that incorporate nonlinear dynamics and thresholds, such as state-and-transition models (STMs), are increasingly popular tools for land management decision-making. However, few models are based on systematic collection and documentation of ecological data, and of these, most rely solely on structural indicators (species composition) to identify states and transitions. As STMs are adopted as an assessment framework throughout the United States, finding effective and efficient ways to create data-driven models that integrate ecosystem function and structure is vital. This study aims to (1) evaluate the utility of functional indicators (indicators of rangeland health, IRH) as proxies for more difficult ecosystem function measurements and (2) create a data-driven STM for the sagebrush steppe of Colorado, USA, that incorporates both ecosystem structure and function. We sampled soils, plant communities, and IRH at 41 plots with similar clayey soils but different site histories to identify potential states and infer the effects of management practices and disturbances on transitions. We found that many IRH were correlated with quantitative measures of functional indicators, suggesting that the IRH can be used to approximate ecosystem function. In addition to a reference state that functions as expected for this soil type, we identified four biotically and functionally distinct potential states, consistent with the theoretical concept of alternate states. Three potential states were related to management practices (chemical and mechanical shrub treatments and seeding history) while one was related only to ecosystem processes (erosion). IRH and potential states were also related to environmental variation (slope, soil texture), suggesting that there are environmental factors within areas with similar soils that affect ecosystem dynamics and should be noted within STMs. Our approach generated an objective, data-driven model of ecosystem dynamics

Retaining of botanical diversity of steppe ecosystems at the Semipalatinsk test site area

International Nuclear Information System (INIS)

Sultanova, B.M.

2005-01-01

The nuclear tests conducted on the STS area have an effect on steppe biome. Regime of military secrecy allowed retaining extensive diversity of steppe vegetation at the area of the former Semipalatinsk test site, although the vegetation was liquidated in the most part of Kazakhstan. Unique biologic diversity of the steppe vegetation requires status of particularly secured vegetation of the STS area. (author)

SPATIAL AND TEMPORAL VARIABILITY OF DRY STEPPES OF EASTERN MONGOLIA

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Galina Ogureeva

2011-01-01

Full Text Available Spatial-temporal structure and coenotic diversity of dry steppes of Eastern Mongolia was identified by analyzing characteristics of naturally occurring vegetation connection to the regional landscape structure. Different types of combinations of plant communities (phytocoenochores were determined in the vegetation structure of the Eastern Steppe Station Tumén-Tsogt (in Sukhebator district. Temporal dynamics of steppe ecosystems was defined from the studies of steppe cover fluctuations in 2008. The coenotic role of eight annual plant species that form synusiae in the steppe communities was shown through analysis of species constancy, projective cover, and activity. Knowledge about the trend of successions and the manifestation of fluctuations in vegetation cover is necessary for the development of science-based system of management options to maintain the number and abundance of different plant groups in plant communities. Monitoring the state of natural ecosystems has a major scientific and practical importance, since steppe ecosystems are the basic component of the pasture’s resources of the country.

Conversion of sagebrush shrublands to exotic annual grasslands negatively impacts small mammal communities

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Ostoja, S.M.; Schupp, E.W.

2009-01-01

Aim The exotic annual cheatgrass (Bromus tectorum) is fast replacing sagebrush (Artemisia tridentata) communities throughout the Great Basin Desert and nearby regions in the Western United States, impacting native plant communities and altering fire regimes, which contributes to the long-term persistence of this weedy species. The effect of this conversion on native faunal communities remains largely unexamined. We assess the impact of conversion from native perennial to exotic annual plant communities on desert rodent communities. Location Wyoming big sagebrush shrublands and nearby sites previously converted to cheatgrass-dominated annual grasslands in the Great Basin Desert, Utah, USA. Methods At two sites in Tooele County, Utah, USA, we investigated with Sherman live trapping whether intact sagebrush vegetation and nearby converted Bromus tectorum-dominated vegetation differed in rodent abundance, diversity and community composition. Results Rodent abundance and species richness were considerably greater in sagebrush plots than in cheatgrass-dominated plots. Nine species were captured in sagebrush plots; five of these were also trapped in cheatgrass plots, all at lower abundances than in the sagebrush. In contrast, cheatgrass-dominated plots had no species that were not found in sagebrush. In addition, the site that had been converted to cheatgrass longer had lower abundances of rodents than the site more recently converted to cheatgrass-dominated plots. Despite large differences in abundances and species richness, Simpson's D diversity and Shannon-Wiener diversity and Brillouin evenness indices did not differ between sagebrush and cheatgrass-dominated plots. Main conclusions This survey of rodent communities in native sagebrush and in converted cheatgrass-dominated vegetation suggests that the abundances and community composition of rodents may be shifting, potentially at the larger spatial scale of the entire Great Basin, where cheatgrass continues to invade

Evaluating winter/spring seeding of a native perennial bunchgrass in the sagebrush steppe

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Sagebrush (Artemisia tridentata Nutt.) plant communities in the US Great Basin region are being severely impacted by increasingly frequent wildfires in association with the expansion of exotic annual grasses. Maintenance of native perennial bunchgrasses is key to controlling annual grass expansion,...

A cross-scale approach to understand drought-induced variability of sagebrush ecosystem productivity

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Assal, T.; Anderson, P. J.

2016-12-01

Sagebrush (Artemisia spp.) mortality has recently been reported in the Upper Green River Basin (Wyoming, USA) of the sagebrush steppe of western North America. Numerous causes have been suggested, but recent drought (2012-13) is the likely mechanism of mortality in this water-limited ecosystem which provides critical habitat for many species of wildlife. An understanding of the variability in patterns of productivity with respect to climate is essential to exploit landscape scale remote sensing for detection of subtle changes associated with mortality in this sparse, uniformly vegetated ecosystem. We used the standardized precipitation index to characterize drought conditions and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery (250-m resolution) to characterize broad characteristics of growing season productivity. We calculated per-pixel growing season anomalies over a 16-year period (2000-2015) to identify the spatial and temporal variability in productivity. Metrics derived from Landsat satellite imagery (30-m resolution) were used to further investigate trends within anomalous areas at local scales. We found evidence to support an initial hypothesis that antecedent winter drought was most important in explaining reduced productivity. The results indicate drought effects were inconsistent over space and time. MODIS derived productivity deviated by more than four standard deviations in heavily impacted areas, but was well within the interannual variability in other areas. Growing season anomalies highlighted dramatic declines in productivity during the 2012 and 2013 growing seasons. However, large negative anomalies persisted in other areas during the 2014 growing season, indicating lag effects of drought. We are further investigating if the reduction in productivity is mediated by local biophysical properties. Our analysis identified spatially explicit patterns of ecosystem properties altered by severe drought which are consistent with

Weak interspecific interactions in a sagebrush steppe? Conflicting evidence from observations and experiments.

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Adler, Peter B; Kleinhesselink, Andrew; Giles, Hooker; Taylor, J Bret; Teller, Brittany; Ellner, Stephen P

2018-04-28

Stable coexistence requires intraspecific limitations to be stronger than interspecific limitations. The greater the difference between intra- and interspecific limitations, the more stable the coexistence, and the weaker the competitive release any species should experience following removal of competitors. We conducted a removal experiment to test whether a previously estimated model, showing surprisingly weak interspecific competition for four dominant species in a sagebrush steppe, accurately predicts competitive release. Our treatments were 1) removal of all perennial grasses and 2) removal of the dominant shrub, Artemisia tripartita. We regressed survival, growth and recruitment on the locations, sizes, and species identities of neighboring plants, along with an indicator variable for removal treatment. If our "baseline" regression model, which accounts for local plant-plant interactions, accurately explains the observed responses to removals, then the removal coefficient should be non-significant. For survival, the removal coefficients were never significantly different from zero, and only A. tripartita showed a (negative) response to removals at the recruitment stage. For growth, the removal treatment effect was significant and positive for two species, Poa secunda and Pseudoroegneria spicata, indicating that the baseline model underestimated interspecific competition. For all three grass species, population models based on the vital rate regressions that included removal effects projected 1.4 to 3-fold increases in equilibrium population size relative to the baseline model (no removal effects). However, we found no evidence of higher response to removal in quadrats with higher pretreatment cover of A. tripartita, or by plants experiencing higher pre-treatment crowding by A. tripartita, raising questions about the mechanisms driving the positive response to removal. While our results show the value of combining observations with a simple removal experiment

Data set on the effects of conifer control and slash burning on soil carbon, total N, organic matter and extractable micro-nutrients

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Jonathan D. Bates

2017-10-01

Full Text Available Conifer control in sagebrush steppe of the western United States causes various levels of site disturbance influencing vegetation recovery and resource availability. The data set presented in this article include growing season availability of soil micronutrients and levels of total soil carbon, organic matter, and N spanning a six year period following western juniper (Juniperus occidentalis spp. occidentalis reduction by mechanical cutting and prescribed fire of western juniper woodlands in southeast Oregon. These data can be useful to further evaluate the impacts of conifer woodland reduction to soil resources in sagebrush steppe plant communities.

Historical fire regimes, reconstructed from land-survey data, led to complexity and fluctuation in sagebrush landscapes.

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Bukowski, Beth E; Baker, William L

2013-04-01

Sagebrush landscapes provide habitat for Sage-Grouse and other sagebrush obligates, yet historical fire regimes and the structure of historical sagebrush landscapes are poorly known, hampering ecological restoration and management. To remedy this, General Land Office Survey (GLO) survey notes were used to reconstruct over two million hectares of historical vegetation for four sagebrush-dominated (Artemisia spp.) study areas in the western United States. Reconstructed vegetation was analyzed for fire indicators used to identify historical fires and reconstruct historical fire regimes. Historical fire-size distributions were inverse-J shaped, and one fire > 100 000 ha was identified. Historical fire rotations were estimated at 171-342 years for Wyoming big sagebrush (A. tridentata ssp. wyomingensis) and 137-217 years for mountain big sagebrush (A. tridentata ssp. vaseyana). Historical fire and patch sizes were significantly larger in Wyoming big sagebrush than mountain big sagebrush, and historical fire rotations were significantly longer in Wyoming big sagebrush than mountain big sagebrush. Historical fire rotations in Wyoming were longer than those in other study areas. Fine-scale mosaics of burned and unburned area and larger unburned inclusions within fire perimeters were less common than in modern fires. Historical sagebrush landscapes were dominated by large, contiguous areas of sagebrush, though large grass-dominated areas and finer-scale mosaics of grass and sagebrush were also present in smaller amounts. Variation in sagebrush density was a common source of patchiness, and areas classified as "dense" made up 24.5% of total sagebrush area, compared to 16.3% for "scattered" sagebrush. Results suggest significant differences in historical and modern fire regimes. Modern fire rotations in Wyoming big sagebrush are shorter than historical fire rotations. Results also suggest that historical sagebrush landscapes would have fluctuated, because of infrequent

Effects of land cover and regional climate variations on long-term spatiotemporal changes in sagebrush ecosystems

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Xian, George Z.; Homer, Collin G.; Aldridge, Cameron L.

2012-01-01

This research investigated the effects of climate and land cover change on variation in sagebrush ecosystems. We combined information of multi-year sagebrush distribution derived from multitemporal remote sensing imagery and climate data to study the variation patterns of sagebrush ecosystems under different potential disturbances. We found that less than 40% of sagebrush ecosystem changes involved abrupt changes directly caused by landscape transformations and over 60% of the variations involved gradual changes directly related to climatic perturbations. The primary increases in bare ground and declines in sagebrush vegetation abundance were significantly correlated with the 1996-2006 decreasing trend in annual precipitation.

Natural regeneration processes in big sagebrush (Artemisia tridentata)

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Schlaepfer, Daniel R.; Lauenroth, William K.; Bradford, John B.

2014-01-01

Big sagebrush, Artemisia tridentata Nuttall (Asteraceae), is the dominant plant species of large portions of semiarid western North America. However, much of historical big sagebrush vegetation has been removed or modified. Thus, regeneration is recognized as an important component for land management. Limited knowledge about key regeneration processes, however, represents an obstacle to identifying successful management practices and to gaining greater insight into the consequences of increasing disturbance frequency and global change. Therefore, our objective is to synthesize knowledge about natural big sagebrush regeneration. We identified and characterized the controls of big sagebrush seed production, germination, and establishment. The largest knowledge gaps and associated research needs include quiescence and dormancy of embryos and seedlings; variation in seed production and germination percentages; wet-thermal time model of germination; responses to frost events (including freezing/thawing of soils), CO2 concentration, and nutrients in combination with water availability; suitability of microsite vs. site conditions; competitive ability as well as seedling growth responses; and differences among subspecies and ecoregions. Potential impacts of climate change on big sagebrush regeneration could include that temperature increases may not have a large direct influence on regeneration due to the broad temperature optimum for regeneration, whereas indirect effects could include selection for populations with less stringent seed dormancy. Drier conditions will have direct negative effects on germination and seedling survival and could also lead to lighter seeds, which lowers germination success further. The short seed dispersal distance of big sagebrush may limit its tracking of suitable climate; whereas, the low competitive ability of big sagebrush seedlings may limit successful competition with species that track climate. An improved understanding of the

Steppe of Tbilisi environs (East Georgia, South Caucasus

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N.J. Lachashvili

2017-09-01

Full Text Available Steppes of Tbilisi environs are studied. In the Tbilisi surroundings the steppe vegetation is either of primary or secondary origin. Steppe vegetation in the Tbilisi environs are represented by 4 formations: (1 Bothriochloeta ischaemum, (2 Festuceta valesiaci, (3 Stipeta pennatae and (4 Gramino-Mixtoherbeta. From them Bothriochloeta ischaemum and Festuceta valesiaci formations have more area covering and characterized by the comparatively rich typological composition. Typological composition of each formation is established. For each separated plant communities the basic structural characteristics (general projective coverage, sodding degree, dominant-edificatory plant, characteristic species, number of species, moss cover, litter, species richness, spectrum of life forms, distribution area in the Tbilisi environs and main physical-geographical conditions (altitude, exposure, inclination, soil type are given.

A conservation paradox in the Great Basin—Altering sagebrush landscapes with fuel breaks to reduce habitat loss from wildfire

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Shinneman, Douglas J.; Aldridge, Cameron L.; Coates, Peter S.; Germino, Matthew J.; Pilliod, David S.; Vaillant, Nicole M.

2018-03-15

Interactions between fire and nonnative, annual plant species (that is, “the grass/fire cycle”) represent one of the greatest threats to sagebrush (Artemisia spp.) ecosystems and associated wildlife, including the greater sage-grouse (Centrocercus urophasianus). In 2015, U.S. Department of the Interior called for a “science-based strategy to reduce the threat of large-scale rangeland fire to habitat for the greater sage-grouse and the sagebrush-steppe ecosystem.” An associated guidance document, the “Integrated Rangeland Fire Management Strategy Actionable Science Plan,” identified fuel breaks as high priority areas for scientific research. Fuel breaks are intended to reduce fire size and frequency, and potentially they can compartmentalize wildfire spatial distribution in a landscape. Fuel breaks are designed to reduce flame length, fireline intensity, and rates of fire spread in order to enhance firefighter access, improve response times, and provide safe and strategic anchor points for wildland fire-fighting activities. To accomplish these objectives, fuel breaks disrupt fuel continuity, reduce fuel accumulation, and (or) increase plants with high moisture content through the removal or modification of vegetation in strategically placed strips or blocks of land.Fuel breaks are being newly constructed, enhanced, or proposed across large areas of the Great Basin to reduce wildfire risk and to protect remaining sagebrush ecosystems (including greater sage-grouse habitat). These projects are likely to result in thousands of linear miles of fuel breaks that will have direct ecological effects across hundreds of thousands of acres through habitat loss and conversion. These projects may also affect millions of acres indirectly because of edge effects and habitat fragmentation created by networks of fuel breaks. Hence, land managers are often faced with a potentially paradoxical situation: the need to substantially alter sagebrush habitats with fuel breaks

Artemisia pollen-indicated steppe distribution in southern China during the Last Glacial Maximum

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Liu Hongyan

2013-07-01

Full Text Available The Last Glacial Maximum (LGM was the coldest period during the previous 20,000 years. There have been different points of views on steppe distribution during the LGM period in southern China, partly due to the different interpretations of Artemisia occurrences. To make a reliable interpretation of the pollen fossil Artemisia, the modern distribution of Artemisia species and the relationship of pollen with climate and vegetation over a large spatial scale in China was thoroughly analyzed. Information about Artemisia species and pollen distributions used in this paper were collected from published works completed by other researchers as well as ourselves. The southern limit of steppe vegetation during the LGM period was interpreted from the published contour map of Artemisia pollen percentages during the LGM. Artemisia species in China are mostly distributed either in the horizontally distributed steppe regions or in the vertically distributed desert-steppe in the desert region, which indicates a cold and dry climate. The steppe is a distribution center of Artemisia pollen. Fractions of Artemisia in surface pollen assemblages are lower in both the desert and the temperate forest. Neither high Artemisia species cover nor high percentages of Artemisia pollen were found in the coast areas of China. Twenty-five percent of Artemisia pollen in sediments might indicate a local occurrence of steppe vegetation. Percentages of Artemisia pollen in the subtropical and tropical forest are less than 10%. A close relationship between Artemisia pollen and temperate steppe in China is demonstrated. The southern edge of the steppe vegetation during the LGM might be along the middle reach of the Yangtze River. Our results support the hypothesis that the isolated high fraction of Artemisia pollen along the northern edge of the South China Sea was transported from a large source area.

Ecological influence and pathways of land use in sagebrush

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Knick, Steven T.; Hanser, Steven E.; Miller, Richard F.; Pyke, David A.; Wisdom, Michael J.; Finn, Sean P.; Rinkes, E. Thomas; Henny, Charles J.; Knick, Steven T.; Connelly, John W.

2011-01-01

Land use in sagebrush (Artemisia spp.) landscapes influences all sage-grouse (Centrocer-cus spp.) populations in western North America. Croplands and the network of irrigation canals cover 230,000 km2 and indirectly influence up to 77% of the Sage-Grouse Conservation Area and 73% of sagebrush land cover by subsidizing synanthropic predators on sage-grouse. Urbanization and the demands of human population growth have created an extensive network of con-necting infrastructure that is expanding its influence on sagebrush landscapes. Over 2,500 km2 are now covered by interstate highways and paved roads; when secondary roads are included, 15% of the Sage-Grouse Conservation Area and 5% of existing sagebrush habitats are 2.5 km from roads. Density of secondary roads often exceeds 5 km/km2, resulting in widespread motorized access for recreation, creating extensive travel corridors for management actions and resource development, subsidizing predators adapted to human presence, and facilitating spread of exotic or invasive plants. Sagebrush lands also are being used for their wilderness and recreation values, including off highway vehicle use. Approximately 12,000,000 animal use months (AUM amount of forage to support one livestock unit per month) are permitted for grazing livestock on public lands in the western states. Direct effects of grazing on sage-grouse populations or sagebrush landscapes are not possible to assess from current data. However, management of lands grazed by livestock has influenced sagebrush ecosystems by vegetation treatments to increase forage and reduce sagebrush and other plant species unpalatable to livestock. Fences (2 km/km2 in some regions), roads, and water developments to manage livestock movements further modify the landscape. Oil and gas development influences 8% of the sagebrush habitats with the highest intensities occurring in the eastern range of sage-grouse; 20% of the sagebrush distribution is indirectly influenced in the Great

W-519 Sagebrush Mitigation Project FY-2004 Final Review and Status

Energy Technology Data Exchange (ETDEWEB)

Durham, Robin E.; Sackschewsky, Michael R.

2004-09-30

This report summarizes activities conducted as mitigation for loss of sagebrush-steppe habitats due to Project W-519, the construction of the infrastructure for the Tank Waste Remediation System Vitrification Plant. The focus of this report is to provide a review and final status of mitigation actions performed through FY2004. Data collected since FY1999 have been included where appropriate. The Mitigation Action Plan (MAP) for Project W-519 prescribed three general actions to be performed as mitigation for the disturbance of approximately 40 ha (100 acres) of mature sagebrush-steppe habitat. These actions included: (1) transplanting approximately 130,000 sagebrush seedlings on the Fitzner-Eberhardt Arid Lands Ecology Reserve (ALE); (2) rectification of the new transmission line corridor via seeding with native grasses and sagebrush; and (3) research on native plant species with a goal of increasing species diversity in future mitigation or restoration actions. Nearly 130,000 Wyoming big sagebrush seedlings where planted on ALE during FY2000 and FY2001. About 39,000 of those seedlings were burned during the 24-Command Fire of June 2000. The surviving and subsequent replanting has resulted in about 91,000 seedlings that were planted across four general areas on ALE. A 50% survival rate at any monitoring period was defined as the performance standard in the MAP for this project. Data collected in 2004 indicate that of the over 5000 monitored plants, 51.1% are still alive, and of those the majority are thriving and blooming. These results support the potential for natural recruitment and the ultimate goal of wildlife habitat replacement. Thus, the basic performance standard for sagebrush survival within the habitat compensation planting has been met. Monitoring activities conducted in 2004 indicate considerable variation in seedling survival depending on the type of plant material, site conditions, and to a lesser extent, treatments performed at the time of planting

W-519 Sagebrush Mitigation Project FY-2004 Final Review and Status

International Nuclear Information System (INIS)

Durham, Robin E.; Sackschewsky, Michael R.

2004-01-01

This report/SUMmarizes activities conducted as mitigation for loss of sagebrush-steppe habitats due to Project W-519, the construction of the infrastructure for the Tank Waste Remediation System Vitrification Plant. The focus of this report is to provide a review and final status of mitigation actions performed through FY2004. Data collected since FY1999 have been included where appropriate. The Mitigation Action Plan (MAP) for Project W-519 prescribed three general actions to be performed as mitigation for the disturbance of approximately 40 ha (100 acres) of mature sagebrush-steppe habitat. These actions included: (1) transplanting approximately 130,000 sagebrush seedlings on the Fitzner-Eberhardt Arid Lands Ecology Reserve (ALE); (2) rectification of the new transmission line corridor via seeding with native grasses and sagebrush; and (3) research on native plant species with a goal of increasing species diversity in future mitigation or restoration actions. Nearly 130,000 Wyoming big sagebrush seedlings where planted on ALE during FY2000 and FY2001. About 39,000 of those seedlings were burned during the 24-Command Fire of June 2000. The surviving and subsequent replanting has resulted in about 91,000 seedlings that were planted across four general areas on ALE. A 50% survival rate at any monitoring period was defined as the performance standard in the MAP for this project. Data collected in 2004 indicate that of the over 5000 monitored plants, 51.1% are still alive, and of those the majority are thriving and blooming. These results support the potential for natural recruitment and the ultimate goal of wildlife habitat replacement. Thus, the basic performance standard for sagebrush survival within the habitat compensation planting has been met. Monitoring activities conducted in 2004 indicate considerable variation in seedling survival depending on the type of plant material, site conditions, and to a lesser extent, treatments performed at the time of planting

Uptake and kinetics of 226Ra, 210Pb and 210Po in big sagebrush

International Nuclear Information System (INIS)

Simon, S.L.

1985-01-01

Root uptake of 226 Ra, 210 Pb and 210 Po by mature sagebrush was studied using a soil injection method for spiking the soil with minimal root disturbance. The main objective was to measure vegetation concentrations and determine concentration ratios (CR's) due to root uptake as a function of time in mature big sagebrush. Concentration ratios obtained in mature vegetation and in steady-state situations may be valuable in assessing the impact of uranium mining and milling. The vegetation was sampled approximately every 3 months for a 2 year period. Significant levels of activity were detected in the vegetation beginning at the first sampling (81 days after soil injection for 226 Ra, 28 days for 210 Pb and 210 Po). There was an exponential decrease in concentration to an apparent steady-state value. Mean values (geometric) of the data pooled over the second year period indicated that the steady-state CR's for 226 Ra, 210 Pb and 210 Po, as determined in mature sagebrush, were 0.04, 0.009, and 0.08, respectively. A three compartment mathematical model was formulated to help understand mechanisms of plant uptake and to predict, if possible, the concentration of 226 Ra, 210 Pb and 210 Po in vegetation as a function of time after soil spiking. A numerical solution was determined by 'calibrating' the general model solution with constants determined from regressions of concentrations in vegetation, soil leaching and leaf leaching data. Validation of the model is currently not possible because of an absence of similar time-dependent uptake studies. 168 refs., 19 figs., 18 tabs

Improving Rangeland Monitoring and Assessment: Integrating Remote Sensing, GIS, and Unmanned Aerial Vehicle Systems

Energy Technology Data Exchange (ETDEWEB)

Robert Paul Breckenridge

2007-05-01

Creeping environmental changes are impacting some of the largest remaining intact parcels of sagebrush steppe ecosystems in the western United States, creating major problems for land managers. The Idaho National Laboratory (INL), located in southeastern Idaho, is part of the sagebrush steppe ecosystem, one of the largest ecosystems on the continent. Scientists at the INL and the University of Idaho have integrated existing field and remotely sensed data with geographic information systems technology to analyze how recent fires on the INL have influenced the current distribution of terrestrial vegetation. Three vegetation mapping and classification systems were used to evaluate the changes in vegetation caused by fires between 1994 and 2003. Approximately 24% of the sagebrush steppe community on the INL was altered by fire, mostly over a 5-year period. There were notable differences between methods, especially for juniper woodland and grasslands. The Anderson system (Anderson et al. 1996) was superior for representing the landscape because it includes playa/bare ground/disturbed area and sagebrush steppe on lava as vegetation categories. This study found that assessing existing data sets is useful for quantifying fire impacts and should be helpful in future fire and land use planning. The evaluation identified that data from remote sensing technologies is not currently of sufficient quality to assess the percentage of cover. To fill this need, an approach was designed using both helicopter and fixed wing unmanned aerial vehicles (UAVs) and image processing software to evaluate six cover types on field plots located on the INL. The helicopter UAV provided the best system compared against field sampling, but is more dangerous and has spatial coverage limitations. It was reasonably accurate for dead shrubs and was very good in assessing percentage of bare ground, litter and grasses; accuracy for litter and shrubs is questionable. The fixed wing system proved to be

Range-wide assessment of livestock grazing across the sagebrush biome

Science.gov (United States)

Veblen, Kari E.; Pyke, David A.; Jones, Christopher A.; Casazza, Michael L.; Assal, Timothy J.; Farinha, Melissa A.

2011-01-01

frequency of data collection varied across allotments and field offices. Analysis of the BLM's LHS data indicated 67 percent of allotments analyzed were meeting standards. For those not meeting standards, livestock were considered the causal factor in 45 percent of cases (about 15 percent of all allotments). Objective 3: We sought input from 42 university and federal rangeland science experts about how best to prioritize rangeland monitoring activities associated with ascertaining livestock impacts on vegetation resources. When we presented a hypothetical scenario to these scientists and asked them to prioritize monitoring activities, the most common response was to measure ground and vegetation cover, a variable that in many cases (10 of 13 field offices sampled) BLM had already identified as a monitoring priority. Experts identified several other traditional (for example, photo points) and emerging approaches (for example, high-resolution aerial photography) to monitoring. Objective 4: We used spatial allotment data (described in Objective 1) and remotely sensed vegetation data (sagebrush cover, herbaceous vegetation cover, litter and bare soil) to assess differences in allotment LHS status ("Not met" vs. "Met"; if "Not met" - livestock-caused vs. not). We then developed logistic regression models, using vegetation variables to predict LHS status of BLM allotments in sagebrush steppe habitats in Wyoming and portions of Montana and Colorado. In general, we found that more consistent data collection at the local level might improve suitability of data for broad-scale analyses of livestock impacts. As is, data collection methodologies varied across field offices and States, and we did not find any local-level monitoring data (Actual Use, Utilization, Vegetation Trend) that had been collected consistently enough over time or space for range-wide analyses. Moreover, continued and improved emphasis on monitoring also may aid local management decisions, particularly with respect

Sagebrush ecosystems: current status and trends.

Science.gov (United States)

Beever, E.A.; Connelly, J.W.; Knick, S.T.; Schroeder, M.A.; Stiver, S. J.

2004-01-01

The sagebrush (Artemisia spp.) biome has changed since settlement by Europeans. The current distribution, composition and dynamics, and disturbance regimes of sagebrush ecosystems have been altered by interactions among disturbance, land use, and invasion of exotic plants. In this chapter, we present the dominant factors that have influenced habitats across the sagebrush biome. Using a large-scale analysis, we identified regional changes and patterns in “natural disturbance”, invasive exotic species, and influences of land use in sagebrush systems. Number of fires and total area burned has increased since 1980 across much of the sagebrush biome. Juniper (Juniperus spp.) and pinyon (Pinus spp.) woodlands have expanded into sagebrush habitats at higher elevations. Cheatgrass (Bromus tectorum), an exotic annual grass, has invaded much of lower elevation, more xeric sagebrush landscapes across the western portion of the biome. Consequently, synergistic feedbacks between habitats and disturbance (natural and human-caused) have altered disturbance regimes, plant community dynamics and contributed to loss of sagebrush habitats and change in plant communities. Habitat conversion to agriculture has occurred in the highly productive regions of the sagebrush biome and influenced up to 56% of the Conservation Assessment area. Similarly, urban areas, and road, railroad, and powerline networks fragment habitats, facilitate predator movements, and provide corridors for spread of exotic species across the entire sagebrush biome. Livestock grazing has altered sagebrush habitats; the effects of overgrazing combined with drought on plant communities in the late 1880s and early 1900s still influences current habitats. Management of livestock grazing has influenced sagebrush ecosystems by habitat treatments to increase forage and reduce sagebrush and other plant species unpalatable to livestock. Fences, roads, and water developments to manage livestock movements have further

Quantifying phenology metrics from Great Basin plant communities and their relationship to seasonal water availability

Science.gov (United States)

Background/Question/Methods Sagebrush steppe is critical habitat in the Great Basin for wildlife and provides important ecosystem goods and services. Expansion of pinyon (Pinus spp.) and juniper (Juniperus spp.) in the Great Basin has reduced the extent of sagebrush steppe causing habitat, fire, and...

Vegetation Responses to Prescribed Burning of Grazed Shortgrass Steppe

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Over the past century, fire has been widely suppressed in the western Great Plains, in part due to potential negative effects on forage production for livestock. More recently, interest in the use of prescribed fire in shortgrass steppe has increased due to potential applications for wildlife manage...

Mid-latitude shrub steppe plant communities: climate change consequences for soil water resources.

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Palmquist, Kyle A; Schlaepfer, Daniel R; Bradford, John B; Lauenroth, William K

2016-09-01

In the coming century, climate change is projected to impact precipitation and temperature regimes worldwide, with especially large effects in drylands. We use big sagebrush ecosystems as a model dryland ecosystem to explore the impacts of altered climate on ecohydrology and the implications of those changes for big sagebrush plant communities using output from 10 Global Circulation Models (GCMs) for two representative concentration pathways (RCPs). We ask: (1) What is the magnitude of variability in future temperature and precipitation regimes among GCMs and RCPs for big sagebrush ecosystems, and (2) How will altered climate and uncertainty in climate forecasts influence key aspects of big sagebrush water balance? We explored these questions across 1980-2010, 2030-2060, and 2070-2100 to determine how changes in water balance might develop through the 21st century. We assessed ecohydrological variables at 898 sagebrush sites across the western US using a process-based soil water model, SOILWAT, to model all components of daily water balance using site-specific vegetation parameters and site-specific soil properties for multiple soil layers. Our modeling approach allowed for changes in vegetation based on climate. Temperature increased across all GCMs and RCPs, whereas changes in precipitation were more variable across GCMs. Winter and spring precipitation was predicted to increase in the future (7% by 2030-2060, 12% by 2070-2100), resulting in slight increases in soil water potential (SWP) in winter. Despite wetter winter soil conditions, SWP decreased in late spring and summer due to increased evapotranspiration (6% by 2030-2060, 10% by 2070-2100) and groundwater recharge (26% and 30% increase by 2030-2060 and 2070-2100). Thus, despite increased precipitation in the cold season, soils may dry out earlier in the year, resulting in potentially longer, drier summer conditions. If winter precipitation cannot offset drier summer conditions in the future, we expect big

Mid-latitude shrub steppe plant communities: Climate change consequences for soil water resources

Science.gov (United States)

Palmquist, Kyle A.; Schlaepfer, Daniel R.; Bradford, John B.; Lauenroth, Willliam K.

2016-01-01

In the coming century, climate change is projected to impact precipitation and temperature regimes worldwide, with especially large effects in drylands. We use big sagebrush ecosystems as a model dryland ecosystem to explore the impacts of altered climate on ecohydrology and the implications of those changes for big sagebrush plant communities using output from 10 Global Circulation Models (GCMs) for two representative concentration pathways (RCPs). We ask: 1) What is the magnitude of variability in future temperature and precipitation regimes among GCMs and RCPs for big sagebrush ecosystems and 2) How will altered climate and uncertainty in climate forecasts influence key aspects of big sagebrush water balance? We explored these questions across 1980-2010, 2030-2060, and 2070-2100 to determine how changes in water balance might develop through the 21st century. We assessed ecohydrological variables at 898 sagebrush sites across the western US using a process-based soil water model, SOILWAT to model all components of daily water balance using site-specific vegetation parameters and site-specific soil properties for multiple soil layers. Our modeling approach allowed for changes in vegetation based on climate. Temperature increased across all GCMs and RCPs, while changes in precipitation were more variable across GCMs. Winter and spring precipitation was predicted to increase in the future (7% by 2030-2060, 12% by 2070-2100), resulting in slight increases in soil water potential (SWP) in winter. Despite wetter winter soil conditions, SWP decreased in late spring and summer due to increased evapotranspiration (6% by 2030-2060, 10% by 2070-2100) and groundwater recharge (26% and 30% increase by 2030-2060 and 2070-2100). Thus, despite increased precipitation in the cold season, soils may dry out earlier in the year, resulting in potentially longer drier summer conditions. If winter precipitation cannot offset drier summer conditions in the future, we expect big

Assessing long-term variations in sagebrush habitat: characterization of spatial extents and distribution patterns using multi-temporal satellite remote-sensing data

Science.gov (United States)

Xian, George; Homer, Collin G.; Aldridge, Cameron L.

2012-01-01

An approach that can generate sagebrush habitat change estimates for monitoring large-area sagebrush ecosystems has been developed and tested in southwestern Wyoming, USA. This prototype method uses a satellite-based image change detection algorithm and regression models to estimate sub-pixel percentage cover for five sagebrush habitat components: bare ground, herbaceous, litter, sagebrush and shrub. Landsat images from three different months in 1988, 1996 and 2006 were selected to identify potential landscape change during these time periods using change vector (CV) analysis incorporated with an image normalization algorithm. Regression tree (RT) models were used to estimate percentage cover for five components on all change areas identified in 1988 and 1996, using unchanged 2006 baseline data as training for both estimates. Over the entire study area (24 950 km2), a net increase of 98.83 km2, or 0.7%, for bare ground was measured between 1988 and 2006. Over the same period, the other four components had net losses of 20.17 km2, or 0.6%, for herbaceous vegetation; 30.16 km2, or 0.7%, for litter; 32.81 km2, or 1.5%, for sagebrush; and 33.34 km2, or 1.2%, for shrubs. The overall accuracy for shrub vegetation change between 1988 and 2006 was 89.56%. Change patterns within sagebrush habitat components differ spatially and quantitatively from each other, potentially indicating unique responses by these components to disturbances imposed upon them.

Light use efficiency over two temperate steppes in inner Mongolia, China.

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Yu Wang

Full Text Available Vegetation light use efficiency (LUE is a key parameter of Production Efficiency Models (PEMs for simulating gross primary production (GPP of vegetation, from regional to global scales. Previous studies suggest that grasslands have the largest inter-site variation of LUE and controlling factors of grassland LUE differ from those of other biomes, since grasslands are usually water-limited ecosystems. Combining eddy covariance flux data with the fraction of photosynthetically active radiation absorbed by the plant canopy from MODIS, we report LUE on a typical steppe and a desert steppe in Inner Mongolia, northern China. Results show that both annual average LUE and maximum LUE were higher on the desert steppe (0.51 and 1.13 g C MJ(-1 than on the typical steppe (0.34 and 0.88 g C MJ(-1, despite the higher GPP of the latter. Water availability was the primary limiting factor of LUE at both sites. Evaporative fraction (EF or the ratio of actual evapotranspiration to potential evapotranspiration (AET/PET can explain 50-70% of seasonal LUE variations at both sites. However, the slope of linear regression between LUE and EF (or AET/PET differed significantly between the two sites. LUE increased with the diffuse radiation ratio on the typical steppe; however, such a trend was not found for the desert steppe. Our results suggest that a biome-dependent LUE(max is inappropriate, because of the large inter-site difference of LUE(max within the biome. EF could be a promising down-regulator on grassland LUE for PEMs, but there may be a site-specific relationship between LUE and EF.

Remote sensing of sagebrush canopy nitrogen

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Mitchell, Jessica J.; Glenn, Nancy F.; Sankey, Temuulen T.; Derryberry, DeWayne R.; Germino, Matthew J.

2012-01-01

This paper presents a combination of techniques suitable for remotely sensing foliar Nitrogen (N) in semiarid shrublands – a capability that would significantly improve our limited understanding of vegetation functionality in dryland ecosystems. The ability to estimate foliar N distributions across arid and semi-arid environments could help answer process-driven questions related to topics such as controls on canopy photosynthesis, the influence of N on carbon cycling behavior, nutrient pulse dynamics, and post-fire recovery. Our study determined that further exploration into estimating sagebrush canopy N concentrations from an airborne platform is warranted, despite remote sensing challenges inherent to open canopy systems. Hyperspectral data transformed using standard derivative analysis were capable of quantifying sagebrush canopy N concentrations using partial least squares (PLS) regression with an R2 value of 0.72 and an R2 predicted value of 0.42 (n = 35). Subsetting the dataset to minimize the influence of bare ground (n = 19) increased R2 to 0.95 (R2 predicted = 0.56). Ground-based estimates of canopy N using leaf mass per unit area measurements (LMA) yielded consistently better model fits than ground-based estimates of canopy N using cover and height measurements. The LMA approach is likely a method that could be extended to other semiarid shrublands. Overall, the results of this study are encouraging for future landscape scale N estimates and represent an important step in addressing the confounding influence of bare ground, which we found to be a major influence on predictions of sagebrush canopy N from an airborne platform.

Steppe development on the Northern Tibetan Plateau inferred from Paleogene ephedroid pollen

NARCIS (Netherlands)

Han, Fang; Rydin, Catarina; Bolinder, Kristina; Dupont-Nivet, Guillaume; Abels, Hemmo A.; Koutsodendris, Andreas; Zhang, Kexin; Hoorn, Carina

2016-01-01

Steppe vegetation represents a key marker of past Asian aridification and is associated with monsoonal intensification. Little is, however, known about the origin of this pre-Oligocene vegetation, its specific composition and how it changed over time and responded to climatic variations. Here, we

Changing Climate and Overgrazing Are Decimating Mongolian Steppes

KAUST Repository

Liu, Yi Y.; Evans, Jason P.; McCabe, Matthew; de Jeu, Richard A. M.; van Dijk, Albert I. J. M.; Dolman, Albertus J.; Saizen, Izuru

2013-01-01

Satellite observations identify the Mongolian steppes as a hotspot of global biomass reduction, the extent of which is comparable with tropical rainforest deforestation. To conserve or restore these grasslands, the relative contributions of climate and human activities to degradation need to be understood. Here we use a recently developed 21-year (1988-2008) record of satellite based vegetation optical depth (VOD, a proxy for vegetation water content and aboveground biomass), to show that nearly all steppe grasslands in Mongolia experienced significant decreases in VOD. Approximately 60% of the VOD declines can be directly explained by variations in rainfall and surface temperature. After removing these climate induced influences, a significant decreasing trend still persists in the VOD residuals across regions of Mongolia. Correlations in spatial patterns and temporal trends suggest that a marked increase in goat density with associated grazing pressures and wild fires are the most likely non-climatic factors behind grassland degradation. © 2013 Liu et al.

Changing climate and overgrazing are decimating Mongolian steppes.

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Yi Y Liu

Full Text Available Satellite observations identify the Mongolian steppes as a hotspot of global biomass reduction, the extent of which is comparable with tropical rainforest deforestation. To conserve or restore these grasslands, the relative contributions of climate and human activities to degradation need to be understood. Here we use a recently developed 21-year (1988-2008 record of satellite based vegetation optical depth (VOD, a proxy for vegetation water content and aboveground biomass, to show that nearly all steppe grasslands in Mongolia experienced significant decreases in VOD. Approximately 60% of the VOD declines can be directly explained by variations in rainfall and surface temperature. After removing these climate induced influences, a significant decreasing trend still persists in the VOD residuals across regions of Mongolia. Correlations in spatial patterns and temporal trends suggest that a marked increase in goat density with associated grazing pressures and wild fires are the most likely non-climatic factors behind grassland degradation.

Changing Climate and Overgrazing Are Decimating Mongolian Steppes

KAUST Repository

Liu, Yi Y.

2013-02-25

Satellite observations identify the Mongolian steppes as a hotspot of global biomass reduction, the extent of which is comparable with tropical rainforest deforestation. To conserve or restore these grasslands, the relative contributions of climate and human activities to degradation need to be understood. Here we use a recently developed 21-year (1988-2008) record of satellite based vegetation optical depth (VOD, a proxy for vegetation water content and aboveground biomass), to show that nearly all steppe grasslands in Mongolia experienced significant decreases in VOD. Approximately 60% of the VOD declines can be directly explained by variations in rainfall and surface temperature. After removing these climate induced influences, a significant decreasing trend still persists in the VOD residuals across regions of Mongolia. Correlations in spatial patterns and temporal trends suggest that a marked increase in goat density with associated grazing pressures and wild fires are the most likely non-climatic factors behind grassland degradation. © 2013 Liu et al.

Calibration of remotely sensed, coarse resolution NDVI to CO2 fluxes in a sagebrush–steppe ecosystem

Science.gov (United States)

Wylie, Bruce K.; Johnson, Douglas A.; Laca, Emilio; Saliendra, Nicanor Z.; Gilmanov, Tagir G.; Reed, Bradley C.; Tieszen, Larry L.; Worstell, Bruce B.

2003-01-01

The net ecosystem exchange (NEE) of carbon flux can be partitioned into gross primary productivity (GPP) and respiration (R). The contribution of remote sensing and modeling holds the potential to predict these components and map them spatially and temporally. This has obvious utility to quantify carbon sink and source relationships and to identify improved land management strategies for optimizing carbon sequestration. The objective of our study was to evaluate prediction of 14-day average daytime CO2 fluxes (Fday) and nighttime CO2 fluxes (Rn) using remote sensing and other data. Fday and Rnwere measured with a Bowen ratio–energy balance (BREB) technique in a sagebrush (Artemisia spp.)–steppe ecosystem in northeast Idaho, USA, during 1996–1999. Micrometeorological variables aggregated across 14-day periods and time-integrated Advanced Very High Resolution Radiometer (AVHRR) Normalized Difference Vegetation Index (iNDVI) were determined during four growing seasons (1996–1999) and used to predict Fday and Rn. We found that iNDVI was a strong predictor of Fday(R2=0.79, n=66, Pimproved predictions of Fday (R2=0.82, n=66, Pmanagement strategies, carbon certification, and validation and calibration of carbon flux models.

About rehabilitation of vegetation of disturbed ecosystems of the Semipalatinsk test sites

International Nuclear Information System (INIS)

Plisak, R.P.; Plisak, S.V.

2005-01-01

Full text: Semipalatinsk Test Sites are the place where 470 nuclear tests were conducted in 1949-1989: 26 surface, 87 air, 357 underground. Total area of polluted territories within the test sites reaches 400 square kilometers and 32 squire kilometers at adjoining territory. Radioactive precipitation spread at the territory of 304 thousand square kilometers by traces of radioactive clouds. The precipitation promoted negative processes in environment and damaged public health. One of the most negative factors is products of nuclear decay after underground nuclear tests. They accumulate in soil. Vertical and horizontal migration of radionuclides occurs. The radionuclides accumulate in plants and reach human organism through food chain. Vegetation cover of former Semipalatinsk Test Sites was partly destroyed or damaged on the test sites mentioned above. Nuclear explosions, military and technical construction, building of roads and communication network were conducted out here. Present vegetation cover of breached areas is represented by plant aggregations and communities. They are attributed to different stages of the process of restoration of initial (steppe) vegetation. Rates of rehabilitation of breached ecosystems are conditioned by degree of moisture and properties of formed technogene substratum (soil texture, presence of detritus, and quantity of fine earth). The higher rates of rehabilitation of breached vegetation are typical for ecosystems of flood lands, depressions between hills and slopes of hills of northern exposition. Rehabilitation of zonal ecosystems (sagebrush-eather-grass communities on light chestnut soils) in conditions of arid climate and insignificant water content in substratum of technogene objects proceeds slowly. Rates of restoration of haloxerophyte communities are conditioned by additional moistening of surface washing down of moist ure into micro depressions occupied by sanotiazol. The process of vegetation rehabilitation of damaged

Dynamic contents of energy and organic nutrient in steppe growths of the Mohelenská Serpentine Steppe National Nature Reserve

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Pavel Veselý

2006-01-01

Full Text Available The aim of the study was to determine the dynamics in the content of organic nutrients, ash and energy in dry matter of growths within the Mohelenská Serpentine Steppe National Nature Reserve (NPR, and to document their initial nutritive value before the intended grazing. Plant samples in 1995 and 1996 during the growing season in 14-days intervals from the area of 3 × 1 m2. Amounts of dry matter, fibre, nitrogen substances, fat and ashes were determined in growths according to the ANONYM (2001. Nitrogen-free extract substances (BNLV were determined by final calculating; BE, ME, NEL, NEV, PDIN and PDIE were calculated using the regression equations (VESELÝ and ZEMAN, 1995, 1997. Combining ratio (SP was calculated according to the relation: SP = PDIN (g/NEL (MJ. The dynamics of the contents of dry matter, organic nutrients, ashes and energy were assessed in the growth during the vegetation period and the dynamics was compared with standardized requirements of sheep (no pregnant ewe. Regression and correlation relations for nutrition value of the growths during vegetation period were calculated by use of mathematical-statistical analysis. Only statistically significantly (P<0.05 different parameters form the zero are presented in the paper. The content of dry matter in the growths culminated in summer months (places D8, E13, B17 and it was accompanied by depression in autumn months. After the highest content of crude protein, PDIN and PDIE recorded in spring months summer depression (August followed, this depression was partly balanced by autumn growth of vegetation. The content of ash in steppe growths increased during evaluated period. Similar tendency was registered for fat. Also the contents of fibre and BNLV linearly increased. The contents of nitrogen nutrients and energy corresponded with standardized requirements for sheep during whole vegetation period. Conversely the content of fibre highly exceeded the requirement except in spring

Spatial variability in cost and success of revegetation in a Wyoming big sagebrush community.

Science.gov (United States)

Boyd, Chad S; Davies, Kirk W

2012-09-01

The ecological integrity of the Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle and A. Young) alliance is being severely interrupted by post-fire invasion of non-native annual grasses. To curtail this invasion, successful post-fire revegetation of perennial grasses is required. Environmental factors impacting post-fire restoration success vary across space within the Wyoming big sagebrush alliance; however, most restorative management practices are applied uniformly. Our objectives were to define probability of revegetation success over space using relevant soil-related environmental factors, use this information to model cost of successful revegetation and compare the importance of vegetation competition and soil factors to revegetation success. We studied a burned Wyoming big sagebrush landscape in southeast Oregon that was reseeded with perennial grasses. We collected soil and vegetation data at plots spaced at 30 m intervals along a 1.5 km transect in the first two years post-burn. Plots were classified as successful (>5 seedlings/m(2)) or unsuccessful based on density of seeded species. Using logistic regression we found that abundance of competing vegetation correctly predicted revegetation success on 51 % of plots, and soil-related variables correctly predicted revegetation performance on 82.4 % of plots. Revegetation estimates varied from $167.06 to $43,033.94/ha across the 1.5 km transect based on probability of success, but were more homogenous at larger scales. Our experimental protocol provides managers with a technique to identify important environmental drivers of restoration success and this process will be of value for spatially allocating logistical and capital expenditures in a variable restoration environment.

Arbuscular mycorrhizal fungi associated with vegetation and soil parameters under rest grazing management in a desert steppe ecosystem.

Science.gov (United States)

Bai, Gegenbaoleer; Bao, Yuying; Du, Guoxin; Qi, Yunlong

2013-05-01

The impact of rest grazing on arbuscular mycorrhizal fungi (AMF) and the interactions of AMF with vegetation and soil parameters under rest grazing condition were investigated between spring and late summer in a desert steppe ecosystem with different grazing managements (rest grazing with different lengths of resting period, banned or continuous grazing) in Inner Mongolia, China. AMF diversity and colonization, vegetation biomass, soil properties and soil phosphatase activity were examined. In rest grazing areas of 60 days, AMF spore number and diversity index at a 0-10 cm soil depth as well as vesicular and hyphal colonization rates were higher compared with other grazing treatments. In addition, soil organic matter and total N contents were highest and soil alkaline phosphatase was most active under 60-day rest grazing. In August and September, these areas also had the highest amount of aboveground vegetation. The results indicated that resting grazing for an appropriate period of time in spring has a positive effect on AMF sporulation, colonization and diversity, and that under rest grazing conditions, AMF parameters are positively correlated with some soil characteristics.

Ecological restoration of peatlands in steppe and forest-steppe areas

Science.gov (United States)

Minayeva, Tatiana; Sirin, Andrey; Dugarjav, Chultem

2016-04-01

Peatlands in the arid and semi-arid regions of steppe and forest steppe belt of Eurasia have some specific features. That demands the special approach to their management and restoration. The distribution of peatlands under conditions of dry climate is very limited and they are extremely vulnerable. Peatlands in those regions are found in the highlands where temperate conditions still present, in floodplains where they can get water from floods and springs, or in karst areas. Peatlands on watersheds present mainly remains from the more humid climate periods. Water and carbon storage as well as maintenance of the specific biodiversity are the key ecosystem natural functions of peatlands in the steppe and forest steppe. The performance of those functions has strong implications for people wellness and livelihood. Anyhow, peatlands are usually overlooked and poorly represented in the systems of natural protected areas. Land management plans, mitigation and restoration measures for ecosystems under use do not usually include special measures for peatlands. Peatlands'use depends on the traditional practices. Peat extraction is rather limited in subhumid regions but still act as one of the threats to peatlands. The most of peatlands are used as pastures and grasslands. In densely populated areas large part of peatlands are transformed to the arable lands. In many cases peatlands of piedmonts and highlands are affected by industrial developments: road construction, mining of subsoil resources (gold, etc.). Until now, the most of peatlands of steppe and forest steppe region are irreversibly lost, what also effects water regime, lands productivity, biodiversity status. To prevent further dramatic changes the ecological restoration approach should be introduced in the subhumid regions. The feasibility study to assess the potential for introducing ecological restoration techniques for peatlands in the arid and semi-arid conditions had been undertaken in steppe and forest

Success of seeding native compared with introduced perennial vegetation for revegetating medusahead-invaded sagebrush rangeland

Science.gov (United States)

Millions of hectares of Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle &Young) rangeland have been invaded by medusahead (Taeniatherum caput-medusae [L.] Nevski), an exotic annual grass that degrades wildlife habitat, reduces forage production, and decreases biodiversity....

A Proposal on the Restoration of Nostoc flagelliforme for Sustainable Improvement in the Ecology of Arid Steppes in China

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Xiang Gao

2016-06-01

Full Text Available Nostoc flagelliforme, a filamentous nitrogen-fixing cyanobacterium, is widely distributed in arid steppes of the west and northwestern parts of China. However, as a food delicacy this species has been overexploited from 1970 to 2000. Moreover, overgrazing, land reclamation and the removal of medicinal herbs have caused severely reduced vegetation coverage there. In this communication, a badly damaged but slowly rehabilitating N. flagelliforme-inhibiting steppe is described, and the rehabilitation of desertified steppes by the renewed growth of N. flagelliforme is proposed. The restoration of this dominant nitrogen supplier would be an ecologically sustainable solution for supplementing current measures already taken in the desertified regions. In addition, a goal of 50%–60% vegetation coverage is proposed by the N. flagelliforme restoration.

Seed bank and big sagebrush plant community composition in a range margin for big sagebrush

Science.gov (United States)

Martyn, Trace E.; Bradford, John B.; Schlaepfer, Daniel R.; Burke, Ingrid C.; Laurenroth, William K.

2016-01-01

The potential influence of seed bank composition on range shifts of species due to climate change is unclear. Seed banks can provide a means of both species persistence in an area and local range expansion in the case of increasing habitat suitability, as may occur under future climate change. However, a mismatch between the seed bank and the established plant community may represent an obstacle to persistence and expansion. In big sagebrush (Artemisia tridentata) plant communities in Montana, USA, we compared the seed bank to the established plant community. There was less than a 20% similarity in the relative abundance of species between the established plant community and the seed bank. This difference was primarily driven by an overrepresentation of native annual forbs and an underrepresentation of big sagebrush in the seed bank compared to the established plant community. Even though we expect an increase in habitat suitability for big sagebrush under future climate conditions at our sites, the current mismatch between the plant community and the seed bank could impede big sagebrush range expansion into increasingly suitable habitat in the future.

Effects of projected climate change on vegetation in the Blue Mountains ecoregion, USA

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Becky K. Kerns

2018-04-01

Full Text Available We used autecological, paleoecological, and modeling information to explore the potential effects of climate change on vegetation in the Blue Mountains ecoregion, Oregon (USA. Although uncertainty exists about the exact nature of future vegetation change, we infer that the following are likely to occur by the end of the century: (1 dominance of ponderosa pine and sagebrush will increase in many locations, (2 the forest-steppe ecotone will move upward in latitude and elevation, (3 ponderosa pine will be distributed at higher elevations, (4 subalpine and alpine systems will be replaced by grass species, pine, and Douglas-fir, (5 moist forest types may increase under wetter scenarios, (6 the distribution and abundance of juniper woodlands may decrease if the frequency and extent of wildfire increase, and (7 grasslands and shrublands will increase at lower elevations. Tree growth in energy-limited landscapes (high elevations, north aspects will increase as the climate warms and snowpack decreases, whereas tree growth in water-limited landscapes (low elevations, south aspects will decrease. Ecological disturbances, including wildfire, insect outbreaks, and non-native species, which are expected to increase in a warmer climate, will affect species distribution, tree age, and vegetation structure, facilitating transitions to new combinations of species and vegetation patterns. In dry forests where fire has not occurred for several decades, crown fires may result in high tree mortality, and the interaction of multiple disturbances and stressors will probably exacerbate stress complexes. Increased disturbance will favor species with physiological and phenological traits that allow them to tolerate frequent disturbance. Keywords: Climate change, Disturbance, Vegetation, Wildfire

MODELING ECONOMIC AND ECOLOGICAL BENEFITS OF POST-FIRE REVEGETATION IN THE GREAT BASIN

OpenAIRE

Niell, Rebecca; Englin, Jeffrey E.; Nalle, Darek

2004-01-01

This study employs a Markov chain model of vegetation dynamics to examine the economic and ecological benefits of post-fire revegetation in the Great Basin sagebrush steppe. The analysis is important because synergies between wildland fire and invasive weeds in this ecosystem are likely to result in the loss of native biodiversity, less predictable forage availability for livestock and wildlife, reduced watershed stability and water quality, and increased costs and risk associated with firefi...

Crop type influences edge effects on the reproduction of songbirds in sagebrush habitat near agriculture

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Elly C. Knight

2014-06-01

Full Text Available Extensive fragmentation of the sagebrush shrubsteppe of western North America could be contributing to observed population declines of songbirds in sagebrush habitat. We examined whether habitat fragmentation impacts the reproduction of songbirds in sagebrush edge habitat near agriculture, and if potential impacts vary depending on the adjacent crop type. Specifically, we evaluated whether nest abundance and nest survival varied between orchard edge habitat, vineyard edge habitat, and interior habitat. We then examined whether the local nest predator community and vegetation could explain the differences detected. We detected fewer nests in edge than interior habitat. Nest abundance per songbird was also lower in edge than interior habitat, although only adjacent to vineyards. Nest predation was more frequent in orchard edge habitat than vineyard edge or interior habitat. Predators identified with nest cameras were primarily snakes, however, reduced nest survival in orchard edge habitat was not explained by differences in the abundance of snakes or any other predator species identified. Information theoretic analysis of daily survival rates showed that greater study plot shrub cover and lower grass height at nests were partially responsible for the lower rate of predation-specific daily nest survival rate (PDSR observed in orchard edge habitat, but additional factors are likely important. Results of this study suggest that different crop types have different edge effects on songbirds nesting in sagebrush shrubsteppe, and that these reproductive edge effects may contribute to observed declines of these species. Habitat managers should avoid the creation of new orchard-sagebrush habitat edges to avoid further impacts on already declining songbird populations.

Ecosystem engineering varies spatially: a test of the vegetation modification paradigm for prairie dogs

Science.gov (United States)

Baker, Bruce W.; Augustine, David J.; Sedgwick, James A.; Lubow, Bruce C.

2013-01-01

Colonial, burrowing herbivores can be engineers of grassland and shrubland ecosystems worldwide. Spatial variation in landscapes suggests caution when extrapolating single-place studies of single species, but lack of data and the need to generalize often leads to ‘model system’ thinking and application of results beyond appropriate statistical inference. Generalizations about the engineering effects of prairie dogs (Cynomys sp.) developed largely from intensive study at a single complex of black-tailed prairie dogs C. ludovicianus in northern mixed prairie, but have been extrapolated to other ecoregions and prairie dog species in North America, and other colonial, burrowing herbivores. We tested the paradigm that prairie dogs decrease vegetation volume and the cover of grasses and tall shrubs, and increase bare ground and forb cover. We sampled vegetation on and off 279 colonies at 13 complexes of 3 prairie dog species widely distributed across 5 ecoregions in North America. The paradigm was generally supported at 7 black-tailed prairie dog complexes in northern mixed prairie, where vegetation volume, grass cover, and tall shrub cover were lower, and bare ground and forb cover were higher, on colonies than at paired off-colony sites. Outside the northern mixed prairie, all 3 prairie dog species consistently reduced vegetation volume, but their effects on cover of plant functional groups varied with prairie dog species and the grazing tolerance of dominant perennial grasses. White-tailed prairie dogs C. leucurus in sagebrush steppe did not reduce shrub cover, whereas black-tailed prairie dogs suppressed shrub cover at all complexes with tall shrubs in the surrounding habitat matrix. Black-tailed prairie dogs in shortgrass steppe and Gunnison's prairie dogs C. gunnisoni in Colorado Plateau grassland both had relatively minor effects on grass cover, which may reflect the dominance of grazing-tolerant shortgrasses at both complexes. Variation in modification of

Investigating Seed Longevity of Big Sagebrush (Artemisia tridentata)

Science.gov (United States)

Wijayratne, Upekala C.; Pyke, David A.

2009-01-01

The Intermountain West is dominated by big sagebrush communities (Artemisia tridentata subspecies) that provide habitat and forage for wildlife, prevent erosion, and are economically important to recreation and livestock industries. The two most prominent subspecies of big sagebrush in this region are Wyoming big sagebrush (A. t. ssp. wyomingensis) and mountain big sagebrush (A. t. ssp. vaseyana). Increased understanding of seed bank dynamics will assist with sustainable management and persistence of sagebrush communities. For example, mountain big sagebrush may be subjected to shorter fire return intervals and prescribed fire is a tool used often to rejuvenate stands and reduce tree (Juniperus sp. or Pinus sp.) encroachment into these communities. A persistent seed bank for mountain big sagebrush would be advantageous under these circumstances. Laboratory germination trials indicate that seed dormancy in big sagebrush may be habitat-specific, with collections from colder sites being more dormant. Our objective was to investigate seed longevity of both subspecies by evaluating viability of seeds in the field with a seed retrieval experiment and sampling for seeds in situ. We chose six study sites for each subspecies. These sites were dispersed across eastern Oregon, southern Idaho, northwestern Utah, and eastern Nevada. Ninety-six polyester mesh bags, each containing 100 seeds of a subspecies, were placed at each site during November 2006. Seed bags were placed in three locations: (1) at the soil surface above litter, (2) on the soil surface beneath litter, and (3) 3 cm below the soil surface to determine whether dormancy is affected by continued darkness or environmental conditions. Subsets of seeds were examined in April and November in both 2007 and 2008 to determine seed viability dynamics. Seed bank samples were taken at each site, separated into litter and soil fractions, and assessed for number of germinable seeds in a greenhouse. Community composition data

How did climate drying reduce ecosystem carbon storage in the forest-steppe ecotone? A case study in Inner Mongolia, China.

Science.gov (United States)

Zhang, Yuke; Liu, Hongyan

2010-07-01

The projected recession of forests in the forest-steppe ecotone under projected climate drying would restrict the carbon sink function of terrestrial ecosystems. Previous studies have shown that the forest-steppe ecotone in the southeastern Inner Mongolia Plateau originally resulted from climate drying and vegetation shifts during the mid- to late-Holocene, but the interrelated processes of changing soil carbon storage and vegetation and soil shifts remain unclear. A total of 44 forest soil profiles and 40 steppe soil profiles were excavated to determine soil carbon storage in deciduous broadleaf forests (DBF), coniferous forests (CF) and steppe (ST) in this area. Carbon density was estimated to be 106.51 t/hm(2) (DBF), 73.20 t/hm(2) (CF), and 28.14 t/hm(2) (ST) for these ecosystems. Soil organic carbon (SOC) content was negatively correlated with sand content (R = -0.879, P ecotone. Changes in carbon storage caused by climate drying can be divided into two stages: (1) carbon storage of the ecosystem was reduced to 68.7%, mostly by soil coarsening when DBF were replaced by CF at approximately 5,900 (14)C years before present (BP); and (2) carbon storage was reduced to 26.4%, mostly by vegetation shifts when CF were replaced by ST at approximately 2,900 (14)C years BP.

Impact of Climate Change and Anthropogenic Activities in the Dynamics of Land Cover in Mediterranean Steppe West Algeria

Science.gov (United States)

Si Tayeb, Tayeb

2016-08-01

The last thirty years, there is a real dynamic change of land cover with intensive degradation of the natural vegetation especially in arid zone. Indeed, the adverse effects of drought periods from the year 1970 combined with population growth and economic conditions experienced by the country in the 1980s have greatly upset the delicate balance of the natural environment. These adverse effects may result in partial or total disappearance of some natural ecosystems.The objective of this work is to study the distribution of plant formations that constitute the ecosystem typical of west Algeria and their dynamics in time and space, as well as to develop a method to monitor the degradation process and a system capable of effectively protecting areas classified for their plant and animal species.The Landsat satellite images were used to map the vegetation of the study area at a scale of 1:200,000. A comparison was then made between the map obtained from satellite images (Landsat 8) of 2014 and (Landsat 5) of 1987.The results show the following main trends in the distribution patterns of steppe species, a strong decrease of land occupied by steppe of Stipatenacissima and steppe of Artimesiaherba-alba, witch replaced by three taxa Thymelaeamicrophylla, Salsolavermiculata and Peganumharmala. Steppe of Artemisia herbaalba has been transformed by steppe of. taxa Thymelaeamicrophylla, Salsolavermiculata and Lygeumspartum. Woody species such as Quercus ilex and Juniperusphoenicea are characterized by a large regression.

Modeling regeneration responses of big sagebrush (Artemisia tridentata) to abiotic conditions

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Schlaepfer, Daniel R.; Lauenroth, William K.; Bradford, John B.

2014-01-01

Ecosystems dominated by big sagebrush, Artemisia tridentata Nuttall (Asteraceae), which are the most widespread ecosystems in semiarid western North America, have been affected by land use practices and invasive species. Loss of big sagebrush and the decline of associated species, such as greater sage-grouse, are a concern to land managers and conservationists. However, big sagebrush regeneration remains difficult to achieve by restoration and reclamation efforts and there is no regeneration simulation model available. We present here the first process-based, daily time-step, simulation model to predict yearly big sagebrush regeneration including relevant germination and seedling responses to abiotic factors. We estimated values, uncertainty, and importance of 27 model parameters using a total of 1435 site-years of observation. Our model explained 74% of variability of number of years with successful regeneration at 46 sites. It also achieved 60% overall accuracy predicting yearly regeneration success/failure. Our results identify specific future research needed to improve our understanding of big sagebrush regeneration, including data at the subspecies level and improved parameter estimates for start of seed dispersal, modified wet thermal-time model of germination, and soil water potential influences. We found that relationships between big sagebrush regeneration and climate conditions were site specific, varying across the distribution of big sagebrush. This indicates that statistical models based on climate are unsuitable for understanding range-wide regeneration patterns or for assessing the potential consequences of changing climate on sagebrush regeneration and underscores the value of this process-based model. We used our model to predict potential regeneration across the range of sagebrush ecosystems in the western United States, which confirmed that seedling survival is a limiting factor, whereas germination is not. Our results also suggested that modeled

Mapping of Vegetation with the Geoinformation System and Determining of Carrying Capacity of the Pre-Urals Steppe area for a Newly Establishing Population of the Przewalski Horse Equus ferus przewalskii at the Orenburg State Nature Reserve

Science.gov (United States)

Fedorov, N. I.; Mikhailenko, O. I.; Zharkikh, T. L.; Bakirova, R. T.

2018-01-01

Mapping of the vegetation (1:25000) of the Pre-Urals Steppe area at the Orenburg State Nature Reserve was completed in 2016. A map created with the geoinformation system contains 1931 simple and complex polygons for 25 types of vegetation. In a drought year, the average stock of palatable vegetation of the whole area is estimated at 8380 tons dry weight. The estimation is based on the size of areas covered by different types of vegetation, their grass production, the correction coefficients for decreasing of pasture forage stocks in winter and decreasing of production of grass communities in dry years. Based on pasture forage stocks the area could tolerate the maximum population size of 1769 individuals of the Przewalski horse, their average density could be 0.11 horse per ha. Yet, as watering places for animals are limited in Pre-Urals Steppe, grazing pressures on the vegetation next to the water sources may increase in dry years. That is why the above-mentioned calculated maximum population size and density must be reduced at least by half until some additional watering places are established and monitoring of the grazing effect on the vegetation next to the places is carried out regularly. Thus, the maximum size of the population is estimated at 800 to 900 individuals, which is almost 1.5 times more than necessary to establish a self-sustained population of the Przewalski horse.

Big and black sagebrush landscapes [Chapter 5

Science.gov (United States)

Stanley G. Kitchen; E. Durant McArthur

2007-01-01

Perhaps no plant evokes a common vision of the semi-arid landscapes of western North America as do the sagebrushes. A collective term, sagebrush is applied to shrubby members of the mostly herbaceous genus, Artemisia L. More precisely, the moniker is usually restricted to members of subgenus Tridentatae, a collection of some 20 woody taxa endemic to North America (...

Comparison of radionuclide levels in soil, sagebrush, plant litter, cryptogams, and small mammals

International Nuclear Information System (INIS)

Landeen, D.S.

1994-09-01

Soil, sagebrush, plant litter, cryptogam, and small mammal samples were collected and analyzed for cesium-137, strontium-90, plutonium-238, plutonium 239/240, technetium-99, and iodine-129 from 1981 to 1986 at the US Department of Energy Hanford Site in southeastern Washington State as part of site characterization and environmental monitoring activities. Samples were collected on the 200 Areas Plateau, downwind from ongoing waste management activities. Plant litter, cryptogams, and small mammals are media that are not routinely utilized in monitoring or characterization efforts for determination of radionuclide concentrations. Studies at Hanford, other US Department of Energy sites, and in eastern Europe have indicated that plant litter and cryptogams may serve as effective ''natural'' monitors of air quality. Plant litter in this study consists of fallen leaves from sagebrush and ''cryptogams'' describes that portion of the soil crust composed of mosses, lichens, algae, and fungi. Comparisons of cesium-137 and strontium-90 concentrations in the soil, sagebrush, litter, and cryptogams revealed significantly higher (p<0.05) levels in plant litter and cryptogams. Technetium-99 values were the highest in sagebrush and litter. Plutonium-238 and 239/40 and iodine-129 concentrations never exceeded 0.8 pCi/gm in all media. No evidence of any significant amounts of any radionuclides being incorporated into the small mammal community was discovered. The data indicate that plant litter and cryptogams may be better, indicators of environmental quality than soil or vegetation samples. Augmenting a monitoring program with samples of litter and cryptogams may provide a more accurate representation of radionuclide environmental uptake and/or contamination levels in surrounding ecosystems. The results of this study may be applied directly to other radioecological monitoring conducted at other nuclear sites and to the monitoring of other pollutants

Ecology of greater sage-grouse in the Dakotas

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Christopher C. Swanson

2009-01-01

Greater sage-grouse (Centrocercus urophasianus) populations and the sagebrush (Artemisia spp.) communities that they rely on have dramatically declined from historic levels. Moreover, information regarding sage-grouse annual life-history requirements at the eastern-most extension of sagebrush steppe communities is lacking....

Vegetation Response to Western Juniper Slash Treatments

Science.gov (United States)

O'Connor, Casey; Miller, Rick; Bates, Jonathan D.

2013-09-01

The expansion of piñon-juniper woodlands the past 100 years in the western United States has resulted in large scale efforts to kill trees and recover sagebrush steppe rangelands. It is important to evaluate vegetation recovery following woodland control to develop best management practices. In this study, we compared two fuel reduction treatments and a cut-and-leave (CUT) treatment used to control western juniper ( Juniperus occidentalis spp. occidentalis Hook.) of the northwestern United States. Treatments were; CUT, cut-and-broadcast burn (BURN), and cut-pile-and-burn the pile (PILE). A randomized complete block design was used with five replicates of each treatment located in a curl leaf mahogany ( Cercocarpus ledifolius Nutt. ex Torr. & A. Gray)/mountain big sagebrush ( Artemisia tridentata Nutt. spp. vaseyana (Rydb.) Beetle)/Idaho fescue ( Festuca idahoensis Elmer) association. In 2010, 4 years after tree control the cover of perennial grasses (PG) [Sandberg's bluegrass ( Poa secunda J. Pres) and large bunchgrasses] were about 4 and 5 % less, respectively, in the BURN (7.1 ± 0.6 %) than the PILE (11.4 ± 2.3 %) and CUT (12.4 ± 1.7 %) treatments ( P < 0.0015). In 2010, cover of invasive cheatgrass ( Bromus tectorum L.) was greater in the BURN (6.3 ± 1.0 %) and was 50 and 100 % greater than PILE and CUT treatments, respectively. However, the increase in perennial bunchgrass density and cover, despite cheatgrass in the BURN treatment, mean it unlikely that cheatgrass will persist as a major understory component. In the CUT treatment mahogany cover increased 12.5 % and density increased in from 172 ± 25 to 404 ± 123 trees/ha. Burning, killed most or all of the adult mahogany, and mahogany recovery consisted of 100 and 67 % seedlings in the PILE and BURN treatments, respectively. After treatment, juniper presence from untreated small trees (<1 m tall; PILE and CUT treatments) and seedling emergence (all treatments) represented 25-33 % of pre-treatment tree

Biological recovery the steppe of Hammada scoparia after enclosure in the region of Naama (Algeria

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Boucherit Hafidha

2017-03-01

Full Text Available This work was being carried out in the steppe of remth (Hammada scoparia in Oranian part of the Saharan Atlas (Tiout - south of Naama. The H. scoparia of Saharan group occupies the foothills south of the Saharan Atlas and glazes and hamadas of the northern part of the Sahara where it seems to find its optimum development. The objective of the study is the floristic and ecological characterisation of the steppe vegetation groups of H. scoparia after 4 years of enclosure grazing (Eg. For the past three decades, steppe of H. scoparia were completely overwhelmed, both in their structure and their operation by increasing the herd and the continued use of natural pastures using animal load significantly higher than the production potential of course, which is reflected by the reduction of their capacity for natural regeneration.

The Bering Land Bridge: a moisture barrier to the dispersal of steppe-tundra biota?

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Elias, Scott A.; Crocker, Barnaby

2008-12-01

The Bering Land Bridge (BLB) connected the two principal arctic biological refugia, Western and Eastern Beringia, during intervals of lowered sea level in the Pleistocene. Fossil evidence from lowland BLB organic deposits dating to the Last Glaciation indicates that this broad region was dominated by shrub tundra vegetation, and had a mesic climate. The dominant ecosystem in Western Beringia and the interior regions of Eastern Beringia was steppe-tundra, with herbaceous plant communities and arid climate. Although Western and Eastern Beringia shared many species in common during the Late Pleistocene, there were a number of species that were restricted to only one side of the BLB. Among the vertebrate fauna, the woolly rhinoceros was found only to the west of the BLB, North American camels, bonnet-horned musk-oxen and some horse species were found only to the east of the land bridge. These were all steppe-tundra inhabitants, adapted to grazing. The same phenomenon can be seen in the insect faunas of the Western and Eastern Beringia. The steppe-tundra beetle fauna of Western Beringia was dominated by weevils of the genus Stephanocleonus, a group that was virtually absent from Eastern Beringia. The dry-adapted weevils, Lepidophorus lineaticollis and Vitavitus thulius were important members of steppe-tundra communities in Eastern Beringia, but were either absent or rare in Western Beringia. The leaf beetles Chrysolina arctica, C. brunnicornis bermani, and Galeruca interrupta circumdata were typical members of the Pleistocene steppe-tundra communities of Western Beringia, but absent from Eastern Beringia. On the other hand, some steppe tundra-adapted leaf beetles managed to occupy both sides of the BLB, such as Phaedon armoraciae. Much of the BLB remains unstudied, but on biogeographic grounds, it appears that there was some kind of biological filter that blocked the movements of some steppe-tundra plants and animals across the BLB.

Conserving and restoring habitat for Greater Sage-Grouse and other sagebrush-obligate wildlife: The crucial link of forbs and sagebrush diversity

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Kas Dumroese; Tara Luna; Bryce A. Richardson; Francis F. Kilkenny; Justin B. Runyon

2015-01-01

In the western US, Greater Sage-Grouse (Centrocercus urophasianus Bonaparte [Phasianidae]) have become an indicator species of the overall health of the sagebrush (Artemisia L. [Asteraceae]) dominated communities that support a rich diversity of flora and fauna. This species has an integral association with sagebrush, its understory forbs and grasses, and the...

Reclamation after oil and gas development does not speed up succession or plant community recovery in big sagebrush ecosystems in Wyoming

Science.gov (United States)

Rottler, Caitlin M.; Burke, Ingrid C.; Palmquist, Kyle A.; Bradford, John B.; Lauenroth, William K.

2018-01-01

Article for intended outlet: Restoration Ecology. Abstract: Reclamation is an application of treatment(s) following a disturbance to promote succession and accelerate the return of target conditions. Previous studies have framed reclamation in the context of succession by studying its effectiveness in re-establishing late-successional plant communities. Re-establishment of these plant communities is especially important and potentially challenging in regions such as drylands and shrub steppe ecosystems where succession proceeds slowly. Dryland shrub steppe ecosystems are frequently associated with areas rich in fossil-fuel energy sources, and as such the need for effective reclamation after disturbance from fossil-fuel-related energy development is great. Past research in this field has focused primarily on coal mines; few researchers have studied reclamation after oil and gas development. To address this research gap and to better understand the effect of reclamation on rates of succession in dryland shrub steppe ecosystems, we sampled oil and gas wellpads and adjacent undisturbed big sagebrush plant communities in Wyoming, USA and quantified the extent of recovery for major functional groups on reclaimed and unreclaimed (recovered via natural succession) wellpads relative to the undisturbed plant community. Reclamation increased the rate of recovery for all forb and grass species as a group and for perennial grasses, but did not affect other functional groups. Rather, analyses comparing recovery to environmental variables and time since wellpad abandonment showed that recovery of other groups were affected primarily by soil texture and time since wellpad abandonment. This is consistent with studies in other ecosystems where reclamation has been implemented, suggesting that reclamation may not help re-establish late-successional plant communities more quickly than they would re-establish naturally.

A multi-proxy record of hydroclimate, vegetation, fire, and post-settlement impacts for a subalpine plateau, Central Rocky Mountains U.S.A

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Anderson, Lesleigh; Brunelle, Andrea; Thompson, Robert S.

2015-01-01

Apparent changes in vegetation distribution, fire, and other disturbance regimes throughout western North America have prompted investigations of the relative importance of human activities and climate change as potential causal mechanisms. Assessing the effects of Euro-American settlement is difficult because climate changes occur on multi-decadal to centennial time scales and require longer time perspectives than historic observations can provide. Here, we report vegetation and environmental changes over the past ~13,000 years as recorded in a sediment record from Bison Lake, a subalpine lake on a high plateau in northwestern Colorado. Results are based on multiple independent proxies, which include pollen, charcoal, and elemental geochemistry, and are compared with previously reported interpretations of hydroclimatic changes from oxygen isotope ratios. The pollen data indicate a slowly changing vegetation sequence from sagebrush steppe during the late glacial to coniferous forest through the late Holocene. The most dramatic vegetation changes of the Holocene occurred during the ‘Medieval Climate Anomaly’ (MCA) and ‘Little Ice Age’ (LIA) with rapid replacement of conifer forest by grassland followed by an equally rapid return to conifer forest. Late Holocene vegetation responses are mirrored by changes in fire, lake biological productivity, and watershed erosion. These combined records indicate that subsequent disturbance related to Euro-American settlement, although perhaps significant, had acted upon a landscape that was already responding to MCA-LIA hydroclimatic change. Results document both rapid and long-term subalpine grassland ecosystem dynamics driven by agents of change that can be anticipated in the future and simulated by ecosystem models.

The Vegetation of North-Western Mongolia: Floristic Checklist and Conservation Status of Mongolian Grassland Flora

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Katharina Lapin

2017-05-01

Full Text Available Mongolia´s grassland (steppe is reported to be vulnerable to climate change, degradation, and densifi cation. The traditional Mongolian pastoral herding system is currently transforming due to changes in market relations and economic developments, and this transformation has an impact on species composition and biodiversity. For this study, we observed the current situation of the fl ora in the north-western Mongolian territories to provide data on plant species occurrence in this remote area. A vegetation assessment was conducted for 15 locations in June and July 2016. Indicator plant species were determined to assess the level of grazing and degradation, as well as the respective steppe sub-type. The conservation status of all recorded plant species was assessed in accordance with the IUCN Red List. In total, 106 vascular plant species belonging to 73 genera and 26 families were recorded. Four endemic plant species were observed. All locations were classifi ed into three steppe sub-types: Desert-steppe, dry-steppe and mountain-steppe. A large number of degradation indicator plant species were observed in almost all locations. No endangered species in the Mongolian IUCN Red List were observed. The observation indicates that the vegetation in the north-western area of Mongolia is partly showing tendencies towards overgrazing and degradation. The conservation status of the most recorded species is currently unknown, and more studies on Mongolian vegetation will need to be conducted to assess these species’ status. We emphasize the urgent need for further studies on the vegetation and plant species composition, and indicators in north-western Mongolia, especially in context of the ongoing rapid economic, social, and ecological changes in the region

Effect of fungicides on Wyoming big sagebrush seed germination

Science.gov (United States)

Robert D. Cox; Lance H. Kosberg; Nancy L. Shaw; Stuart P. Hardegree

2011-01-01

Germination tests of Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young [Asteraceae]) seeds often exhibit fungal contamination, but the use of fungicides should be avoided because fungicides may artificially inhibit germination. We tested the effect of seed-applied fungicides on germination of Wyoming big sagebrush at 2 different...

Sagebrush-ungulate relationships on the Northern Yellowstone Winter Range

Science.gov (United States)

Carl L. Wambolt

2005-01-01

Sagebrush (Artemisia) taxa have historically been the landscape dominants over much of the Northern Yellowstone Winter Range (NYWR). Their importance to the unnaturally large ungulate populations on the NYWR throughout the twentieth century has been recognized since the 1920s. Sagebrush-herbivore ecology has been the focus of research on the NYWR for...

Utility of surface pollen assemblages to delimit Eastern Eurasian steppe types.

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Feng Qin

Full Text Available Modern pollen records have been used to successfully distinguish between specific prairie types in North America. Whether the pollen records can be used to detect the occurrence of Eurasian steppe, or even to further delimit various steppe types was until now unclear. Here we characterized modern pollen assemblages of meadow steppe, typical steppe and desert steppe from eastern Eurasia along an ecological humidity gradient. The multivariate ordination of the pollen data indicated that Eurasian steppe types could be clearly differentiated. The different steppe types could be distinguished primarily by xerophilous elements in the pollen assemblages. Redundancy analysis indicated that the relative abundances of Ephedra, Tamarix, Nitraria and Zygophyllaceae were positively correlated with aridity. The relative abundances of Ephedra increased from meadow steppe to typical steppe and desert steppe. Tamarix and Zygophyllaceae were found in both typical steppe and desert steppe, but not in meadow steppe. Nitraria was only found in desert steppe. The relative abundances of xerophilous elements were greater in desert steppe than in typical steppe. These findings indicate that Eurasian steppe types can be differentiated based on recent pollen rain.

Effect of desertification on productivity in a desert steppe.

Science.gov (United States)

Tang, Zhuangsheng; An, Hui; Deng, Lei; Wang, Yingying; Zhu, Guangyu; Shangguan, Zhouping

2016-06-14

Desertification, one of the most severe types of land degradation in the world, is of great importance because it is occurring, to some degree, on approximately 40% of the global land area and is affecting more than 1 billion people. In this study, we used a space-for-time method to quantify the impact of five different desertification regimes (potential (PD), light (LD), moderate (MD), severe (SD), and very severe (VSD)) on a desert steppe ecosystem in northern China to examine the relationship between the productivity of the vegetation and soil properties and to determine the mechanism underlying the effects of desertification on productivity. Our results showed that the effects of desertification on TP (total phosphorus) and AP (available phosphorus) were not significant, and desertification decreased productivity in the desert steppe as a result of direct changes to soil physical properties, which can directly affect soil chemical properties. Therefore, intensive grassland management to improve soil quality may result in the long-term preservation of ecosystem functions and services.

Ecology and Conservation of Steppes and Semi-Natural Grasslands

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Valkó Orsolya

2016-12-01

Full Text Available Palaearctic grasslands encompass a diverse variety of habitats, many of high nature value and vulnerability. The main challenges are climate-change, land-use change, agricultural intensification and abandonment. Many measures are in place to address these challenges, through restoration and appropriate management, though more work is necessary. We present eight studies from China/Germany, Greece, Kazakhstan, Russia and Ukraine. The papers cover a wide range of grassland and steppe habitats and cover vegetation ecology, syntaxonomy and zoology. We also conducted a systematic search on steppe and grassland diversity. The greatest number of studies was from China, followed by Germany and England. We conclude that the amount of research being carried out on Eurasian grasslands is inadequate considering their high levels of biodiversity and vulnerability. We hope to encourage readers to address current major challenges, such as how to manage grasslands for the benefit of diverse taxa, to ensure that conservation initiatives concentrate on sites where there is good potential for success and for the generation of realistic and viable conservation strategies.

Surface fluxes and water balance of spatially varying vegetation within a small mountainous headwater catchment

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G. N. Flerchinger

2010-06-01

Full Text Available Precipitation variability and complex topography often create a mosaic of vegetation communities in mountainous headwater catchments, creating a challenge for measuring and interpreting energy and mass fluxes. Understanding the role of these communities in modulating energy, water and carbon fluxes is critical to quantifying the variability in energy, carbon, and water balances across landscapes. The focus of this paper was: (1 to demonstrate the utility of eddy covariance (EC systems in estimating the evapotranspiration component of the water balance of complex headwater mountain catchments; and (2 to compare and contrast the seasonal surface energy and carbon fluxes across a headwater catchment characterized by large variability in precipitation and vegetation cover. Eddy covariance systems were used to measure surface fluxes over sagebrush (Artemesia arbuscula and Artemesia tridentada vaseyana, aspen (Populus tremuloides and the understory of grasses and forbs beneath the aspen canopy. Peak leaf area index of the sagebrush, aspen, and aspen understory was 0.77, 1.35, and 1.20, respectively. The sagebrush and aspen canopies were subject to similar meteorological forces, while the understory of the aspen was sheltered from the wind. Missing periods of measured data were common and made it necessary to extrapolate measured fluxes to the missing periods using a combination of measured and simulated data. Estimated cumulative evapotranspiratation from the sagebrush, aspen trees, and aspen understory were 384 mm, 314 mm and 185 mm. A water balance of the catchment indicated that of the 699 mm of areal average precipitation, 421 mm was lost to evapotranspiration, and 254 mm of streamflow was measured from the catchment; water balance closure for the catchment was within 22 mm. Fluxes of latent heat and carbon for all sites were minimal through the winter. Growing season fluxes of latent heat and carbon were consistently higher

Forecasting sagebrush ecosystem components and greater sage-grouse habitat for 2050: learning from past climate patterns and Landsat imagery to predict the future

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Homer, Collin G.; Xian, George Z.; Aldridge, Cameron L.; Meyer, Debra K.; Loveland, Thomas R.; O'Donnell, Michael S.

2015-01-01

Sagebrush (Artemisia spp.) ecosystems constitute the largest single North American shrub ecosystem and provide vital ecological, hydrological, biological, agricultural, and recreational ecosystem services. Disturbances have altered and reduced this ecosystem historically, but climate change may ultimately represent the greatest future risk. Improved ways to quantify, monitor, and predict climate-driven gradual change in this ecosystem is vital to its future management. We examined the annual change of Daymet precipitation (daily gridded climate data) and five remote sensing ecosystem sagebrush vegetation and soil components (bare ground, herbaceous, litter, sagebrush, and shrub) from 1984 to 2011 in southwestern Wyoming. Bare ground displayed an increasing trend in abundance over time, and herbaceous, litter, shrub, and sagebrush showed a decreasing trend. Total precipitation amounts show a downward trend during the same period. We established statistically significant correlations between each sagebrush component and historical precipitation records using a simple least squares linear regression. Using the historical relationship between sagebrush component abundance and precipitation in a linear model, we forecasted the abundance of the sagebrush components in 2050 using Intergovernmental Panel on Climate Change (IPCC) precipitation scenarios A1B and A2. Bare ground was the only component that increased under both future scenarios, with a net increase of 48.98 km2 (1.1%) across the study area under the A1B scenario and 41.15 km2 (0.9%) under the A2 scenario. The remaining components decreased under both future scenarios: litter had the highest net reductions with 49.82 km2 (4.1%) under A1B and 50.8 km2 (4.2%) under A2, and herbaceous had the smallest net reductions with 39.95 km2 (3.8%) under A1B and 40.59 km2 (3.3%) under A2. We applied the 2050 forecast sagebrush component values to contemporary (circa 2006) greater sage-grouse (Centrocercus

over time

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Sara K. Hanna

2015-01-01

Full Text Available Sagebrush steppe ecosystems of the Intermountain West have experienced a decline over the past 150 years due to changing fire regimes, invasive species and conifer encroachment. Prescribed fire is a common and cost-effective tool used in sagebrush restoration and fuels management. We examined the post-fire succession of a sagebrush steppe community over a nearly 30-year period at two study sites in northeastern California. The long-term nature of this study was particularly significant, as invasive annual grasses dominated the plant community in the years immediately following fire, but native perennial grasses and shrubs successfully out-competed them in the long term. Shrubs were slow to recover but had returned to pre-fire levels by the end of the study period. There was also notable increase in western juniper throughout the study sites, particularly in areas that had not been burned. Our results indicate that mean fire return intervals of 50 years or less would help reduce western juniper encroachment and preserve sagebrush habitat, especially for potentially threatened species such as the sage grouse.

76 FR 62087 - Draft Conservation Plan and Draft Environmental Assessment; Dunes Sagebrush Lizard, Texas

Science.gov (United States)

2011-10-06

...] Draft Conservation Plan and Draft Environmental Assessment; Dunes Sagebrush Lizard, Texas AGENCY: Fish... draft Texas Conservation Plan for the Dunes Sagebrush Lizard (TCP). The draft TCP will function as a... the Applicant for the dunes sagebrush lizard (Sceloporus arenicolus) throughout its range in Texas...

Dynamics of sugar content in vegetative organs of Syringa Genus representatives introduced into Steppe Zone

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L. G. Dolgova

2005-12-01

Full Text Available Quantitative and qualitative contents of sugars in phases of growth and development in overground organs of species of Syringa L. genus were determined. It is shown a cryoprotective role of sugars in plants. Conclusions on resistance of plants under conditions of a steppe zone are made.

Varying responses of vegetation activity to climate changes on the Tibetan Plateau grassland.

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Cong, Nan; Shen, Miaogen; Yang, Wei; Yang, Zhiyong; Zhang, Gengxin; Piao, Shilong

2017-08-01

Vegetation activity on the Tibetan Plateau grassland has been substantially enhanced as a result of climate change, as revealed by satellite observations of vegetation greenness (i.e., the normalized difference vegetation index, NDVI). However, little is known about the temporal variations in the relationships between NDVI and temperature and precipitation, and understanding this is essential for predicting how future climate change would affect vegetation activity. Using NDVI data and meteorological records from 1982 to 2011, we found that the inter-annual partial correlation coefficient between growing season (May-September) NDVI and temperature (R NDVI-T ) in a 15-year moving window for alpine meadow showed little change, likely caused by the increasing R NDVI-T in spring (May-June) and autumn (September) and decreasing R NDVI-T in summer (July-August). Growing season R NDVI-T for alpine steppe increased slightly, mainly due to increasing R NDVI-T in spring and autumn. The partial correlation coefficient between growing season NDVI and precipitation (R NDVI-P ) for alpine meadow increased slightly, mainly in spring and summer, and R NDVI-P for alpine steppe increased, mainly in spring. Moreover, R NDVI-T for the growing season was significantly higher in those 15-year windows with more precipitation for alpine steppe. R NDVI-P for the growing season was significantly higher in those 15-year windows with higher temperature, and this tendency was stronger for alpine meadow than for alpine steppe. These results indicate that the impact of warming on vegetation activity of Tibetan Plateau grassland is more positive (or less negative) during periods with more precipitation and that the impact of increasing precipitation is more positive (or less negative) during periods with higher temperature. Such positive effects of the interactions between temperature and precipitation indicate that the projected warmer and wetter future climate will enhance vegetation activity

Water relations and photosynthetic performance in Larix sibirica growing in the forest-steppe ecotone of northern Mongolia.

Science.gov (United States)

Dulamsuren, Choimaa; Hauck, Markus; Bader, Martin; Osokhjargal, Dalaikhuu; Oyungerel, Shagjjav; Nyambayar, Suran; Runge, Michael; Leuschner, Christoph

2009-01-01

region. Higher stomatal conductance concomitant to lower Psi(m) in trees of northern-slope forests compared to trees from the forest line to the steppe may be the result of a recent increase in drought intensity that affects better drought-adapted trees at the forest edge less than the trees in the forest interior. We conclude that drought is a key factor explaining the forest-steppe borderline in northern Mongolia. The proportion of forests within the present vegetation pattern of forests on north-facing slopes and the grasslands on south-facing slopes in Mongolia's forest-steppe ecotone is not likely to increase under the present climate, but may decrease with increasing aridity due to global warming.

76 FR 19304 - Endangered and Threatened Wildlife and Plants; Endangered Status for Dunes Sagebrush Lizard

Science.gov (United States)

2011-04-07

... for Dunes Sagebrush Lizard AGENCY: Fish and Wildlife Service, Interior. ACTION: Proposed rule... list the dunes sagebrush lizard (Sceloporus arenicolus) under the Endangered Species Act of 1973, as... dunes sagebrush lizard (Sceloporus arenicolus) that was published in the Federal Register on December 14...

U.S. Geological Survey sage-grouse and sagebrush ecosystem research annual report for 2017

Science.gov (United States)

Hanser, Steven E.

2017-09-08

The sagebrush (Artemisia spp.) ecosystem extends across a large portion of the Western United States, and the greater sage-grouse (Centrocercus urophasianus) is one of the iconic species of this ecosystem. Greater sage-grouse populations occur in 11 States and are dependent on relatively large expanses of sagebrush-dominated habitat. Sage-grouse populations have been experiencing long-term declines owing to multiple stressors, including interactions among fire, exotic plant invasions, and human land uses, which have resulted in significant loss, fragmentation, and degradation of landscapes once dominated by sagebrush. In addition to the sage-grouse, over 350 species of plants and animals are dependent on the sagebrush ecosystem.Increasing knowledge about how these species and the sagebrush ecosystem respond to these stressors and to management actions can inform and improve strategies to maintain existing areas of intact sagebrush and restore degraded landscapes. The U.S. Geological Survey (USGS) has a broad research program focused on providing the science needed to inform these strate-gies and to help land and resource managers at the Federal, State, Tribal, and local levels as they work towards sustainable sage-grouse populations and restored landscapes for the broad range of uses critical to stakeholders in the Western United States.USGS science has provided a foundation for major land and resource management decisions including those that precluded the need to list the greater sage-grouse under the Endangered Species Act. The USGS is continuing to build on that foundation to inform science-based decisions to help support local economies and the continued conservation, management, and restoration of the sagebrush ecosystem.This report contains descriptions of USGS sage-grouse and sagebrush ecosystem research projects that are ongoing or were active during 2017 and is organized into five thematic areas: Fire, Invasive Species, Restoration, Sagebrush and Sage

Sagebrush, greater sage-grouse, and the occurrence and importance of forbs

Science.gov (United States)

Pennington, Victoria E.; Schlaepfer, Daniel R.; Beck, Jeffrey L.; Bradford, John B.; Palmquist, Kyle A.; Lauenroth, William K.

2016-01-01

Big sagebrush (Artemisia tridentata Nutt.) ecosystems provide habitat for sagebrush-obligate wildlife species such as the Greater Sage-Grouse (Centrocercus urophasianus). The understory of big sagebrush plant communities is composed of grasses and forbs that are important sources of cover and food for wildlife. The grass component is well described in the literature, but the composition, abundance, and habitat role of forbs in these communities is largely unknown. Our objective was to synthesize information about forbs and their importance to Greater Sage-Grouse diets and habitats, how rangeland management practices affect forbs, and how forbs respond to changes in temperature and precipitation. We also sought to identify research gaps and needs concerning forbs in big sagebrush plant communities. We searched for relevant literature including journal articles and state and federal agency reports. Our results indicated that in the spring and summer, Greater Sage-Grouse diets consist of forbs (particularly species in the Asteraceae family), arthropods, and lesser amounts of sagebrush. The diets transition to sagebrush in fall and winter. Forbs provide cover for Greater Sage-Grouse individuals at their lekking, nesting, and brood-rearing sites, and the species has a positive relationship with arthropod presence. The effect of grazing on native forbs may be compounded by invasion of nonnative species and differs depending on grazing intensity. The effect of fire on forbs varies greatly and may depend on time elapsed since burning. In addition, chemical and mechanical treatments affect annual and perennial forbs differently. Temperature and precipitation influence forb phenology, biomass, and abundance differently among species. Our review identified several uncertainties and research needs about forbs in big sagebrush ecosystems. First, in many cases the literature about forbs is reported only at the genus or functional type level. Second, information about forb

A seasonal comparison of deposition velocities and retention half-times for Cs-134 and Ce-141 on cool desert vegetation

International Nuclear Information System (INIS)

Millard, Gloria C.; Fraley, Leslie Jr.; Markham, O.D.

1978-01-01

Due to a scarcity of reliable deposition velocity estimates for radionuclides (particularly those in the submicron range) pooled estimates have been used to predict population doses resulting from atmospheric releases of radioactive particulates. The use of these estimates has led to large uncertainties in whole body dose estimates. Deposition velocities and retention half-times were therefore determined for submicron aerosols of 141 Ce (biologically inactive) and 134 Cs (biologically active) on sagebrush dominated desert vegetation in SE Idaho. Approximately 250 mCi (9.3 GBq) of each radionuclide were released over stands of Artemisia tridentata (big sagebrush) and bottlebrush grass (Sitanion hystrix) during three stages of plant development - spring vegetative growth, seed development, and plant dormancy. Air filters and vegetation samples were collected immediately following each release for use in deposition velocity calculations. Vegetation sampling was continued for a period of three months to obtain retention data. Deposition velocity values were 0.20 cm/s for sagebrush and 0.025 cm/s for grass. The loss of activity on the vegetation seemed to best fit a two component exponential loss function. Short component half-times were 1 to 2 days for both species. Long component half-times were two to three weeks for the shrub species and one to two weeks for the grass species. No significant difference was observed between nuclides. (author)

Simulated big sagebrush regeneration supports predicted changes at the trailing and leading edges of distribution shifts

Science.gov (United States)

Schlaepfer, Daniel R.; Taylor, Kyle A.; Pennington, Victoria E.; Nelson, Kellen N.; Martin, Trace E.; Rottler, Caitlin M.; Lauenroth, William K.; Bradford, John B.

2015-01-01

Many semi-arid plant communities in western North America are dominated by big sagebrush. These ecosystems are being reduced in extent and quality due to economic development, invasive species, and climate change. These pervasive modifications have generated concern about the long-term viability of sagebrush habitat and sagebrush-obligate wildlife species (notably greater sage-grouse), highlighting the need for better understanding of the future big sagebrush distribution, particularly at the species' range margins. These leading and trailing edges of potential climate-driven sagebrush distribution shifts are likely to be areas most sensitive to climate change. We used a process-based regeneration model for big sagebrush, which simulates potential germination and seedling survival in response to climatic and edaphic conditions and tested expectations about current and future regeneration responses at trailing and leading edges that were previously identified using traditional species distribution models. Our results confirmed expectations of increased probability of regeneration at the leading edge and decreased probability of regeneration at the trailing edge below current levels. Our simulations indicated that soil water dynamics at the leading edge became more similar to the typical seasonal ecohydrological conditions observed within the current range of big sagebrush ecosystems. At the trailing edge, an increased winter and spring dryness represented a departure from conditions typically supportive of big sagebrush. Our results highlighted that minimum and maximum daily temperatures as well as soil water recharge and summer dry periods are important constraints for big sagebrush regeneration. Overall, our results confirmed previous predictions, i.e., we see consistent changes in areas identified as trailing and leading edges; however, we also identified potential local refugia within the trailing edge, mostly at sites at higher elevation. Decreasing

Current stage of the restoration of Chernozems in rangeland ecosystems of the steppe zone

Science.gov (United States)

Rusanov, A. M.

2015-06-01

The results of two rounds of soil and geobotanic surveys of rangeland ecosystems in the steppe zone are presented. The same sites with southern chernozems (Calcic Chernozems) under steppe plant communities at different stages of pasture degradation were investigated at the end of the 1980s, when they suffered maximum anthropogenic loads, and in 2011-2013, after a long period of relative rest. In the 1980s, degradation of soil physical properties in rangeland ecosystems under the impact of long-term unsustainable management was noted. At the same time, it was found that the major qualitative and quantitative properties of humus in the chernozems were preserved independently from the level of pasture degradation. The following period of moderate grazing pressure had a favorable effect on the soil properties. Owing to the good characteristics of the soil humus, the restoration of the physical properties of chernozems-including their structural state, water permeability, and bulk density-took place in a relatively short period. It is argued that the soil bulk density is a natural regulator of the species composition of steppe vegetation, because true grasses (Poaceae)-typical representatives of the steppe flora-have a fibrous root system requiring the soils with low density values. The improvement of the properties of chernozems is related to the development of secondary ecosystems with a higher portion of grasses in place of damaged rangelands and to the increase in the area of nominal virgin phytocenoses.

Effects of Plant Functional Group Loss on Soil Microbial Community and Litter Decomposition in a Steppe Vegetation.

Science.gov (United States)

Xiao, Chunwang; Zhou, Yong; Su, Jiaqi; Yang, Fan

2017-01-01

Globally, many terrestrial ecosystems are experiencing a rapid loss of biodiversity. Continued improvements in our understanding of interrelationships between plant diversity and soil microbes are critical to address the concern over the consequences of the decline in biodiversity on ecosystem functioning and services. By removing forbs, or grasses, or, to an extreme scenario, both forbs and grasses in a steppe vegetation in Inner Mongolia, we studied how plant functional group (PFG) loss affects soil microbial community composition using phospholipid fatty acid analysis (PLFA) and litter decomposition using a litter-bag method. PFG loss significantly decreased above- and below-ground plant biomass, soil microbial biomass carbon (SMBC) and nitrogen (SMBN), but had no effect on the ratio of SMBC to SMBN. Although the ratio of fungal to bacterial PLFAs remained unaffected, PFG loss significantly reduced the amount of bacterial, fungal, and total PLFAs. PFG loss decreased litter monthly mass loss and decay constant, and such decrease was significant when both forbs and grasses were removed. Our results provide robust evidence that PFG loss in grassland ecosystem can lead to a rapid response of soil microbial activity which may affect litter decomposition and soil nutrient cycling, suggesting that the assessment of plant-microbe interactions in soils is an integral component of ecosystem response to biodiversity loss.

A method to determine warm and cool steppe biomes from pollen data; application to the Mediterranean and Kazakhstan regions

NARCIS (Netherlands)

Tarasov, PE; Cheddadi, R; Guiot, J; Bottema, S; Peyron, O; Belmonte, J; Ruiz-Sanchez, [No Value; Saadi, F; Brewer, S

1998-01-01

An objective method for the assignment of pollen spectra to appropriate biomes has been published recently. The aim of this paper is to improve the distinction between warm and cool steppes, thus refining vegetation and climate reconstruction, particularly during the Last Glacial Maximum. A set of

The response of big sagebrush (Artemisia tridentata) to interannual climate variation changes across its range.

Science.gov (United States)

Kleinhesselink, Andrew R; Adler, Peter B

2018-05-01

Understanding how annual climate variation affects population growth rates across a species' range may help us anticipate the effects of climate change on species distribution and abundance. We predict that populations in warmer or wetter parts of a species' range should respond negatively to periods of above average temperature or precipitation, respectively, whereas populations in colder or drier areas should respond positively to periods of above average temperature or precipitation. To test this, we estimated the population sensitivity of a common shrub species, big sagebrush (Artemisia tridentata), to annual climate variation across its range. Our analysis includes 8,175 observations of year-to-year change in sagebrush cover or production from 131 monitoring sites in western North America. We coupled these observations with seasonal weather data for each site and analyzed the effects of spring through fall temperatures and fall through spring accumulated precipitation on annual changes in sagebrush abundance. Sensitivity to annual temperature variation supported our hypothesis: years with above average temperatures were beneficial to sagebrush in colder locations and detrimental to sagebrush in hotter locations. In contrast, sensitivity to precipitation did not change significantly across the distribution of sagebrush. This pattern of responses suggests that regional abundance of this species may be more limited by temperature than by precipitation. We also found important differences in how the ecologically distinct subspecies of sagebrush responded to the effects of precipitation and temperature. Our model predicts that a short-term temperature increase could produce an increase in sagebrush cover at the cold edge of its range and a decrease in cover at the warm edge of its range. This prediction is qualitatively consistent with predictions from species distribution models for sagebrush based on spatial occurrence data, but it provides new mechanistic

Greater sage-grouse as an umbrella species for sagebrush-associated vertebrates.

Science.gov (United States)

Mary M. Rowland; Michael J. Wisdom; Lowell Suring; Cara W. Meinke

2006-01-01

Widespread degradation of the sagebrush ecosystem in the western United States, including the invasion of cheatgrass, has prompted resource managers to consider a variety of approaches to restore and conserve habitats for sagebrush-associated species. One such approach involves the use of greater sage-grouse, a species of prominent conservation interest, as an umbrella...

Soil macrofauna (invertebrates of Kazakhstanian Stipa lessingiana dry steppe

Directory of Open Access Journals (Sweden)

Bragina Tatyana М.

2016-12-01

Full Text Available Stipa lessingiana steppes used to be prevalent on the dry Trans-Ural denudation plains, particularly, on the Sub-Ural and the Turgay Plateau. But, most of them have been lost because they were plowed up during the Virgin Land campaign in the second part of 20th century. This paper presents a detailed study of the faunistic composition and the structure of soil-dwelling invertebrate communities (macrofauna of a temperate-dry bunch feather grass steppe in the Turgai Plateau (Northern-Turgai physical-geographical province of steppe Kazakhstan, Kostanay Oblast. The study site is located in the territory of the Naurzum State Nature Reserve, a part of the UNESCO World Heritage site “Saryarka Steppe and Lakes of Northern Kazakhstan”, where remnants of Virgin S. lessingiana steppes have been preserved to the present day. This region is the driest and most continental in climate of all the dry steppes of Kazakhstan. The total abundance and biomass of soil invertebrate communities in the investigated site were lower than in the northern and western steppe areas. Soil invertebrates are among the major components that determine the functioning of terrestrial natural ecosystems.

Simulating the Effect of Climate Change on Vegetation Zone Distribution on the Loess Plateau, Northwest China

Directory of Open Access Journals (Sweden)

Guoqing Li

2015-06-01

Full Text Available A risk assessment of vegetation zone responses to climate change was conducted using the classical Holdridge life zone model on the Loess Plateau of Northwest China. The results show that there are currently ten vegetation zones occurring on the Loess Plateau (1950–2000, including alvar desert, alpine wet tundra, alpine rain tundra, boreal moist forest, boreal wet forest, cool temperate desert, cool temperate desert scrub, cool temperate steppe, cool temperate moist forest, warm temperate desert scrub, warm temperate thorn steppe, and warm temperate dry forest. Seventy years later (2070S, the alvar desert, the alpine wet tundra and the cool temperate desert will disappear, while warm temperate desert scrub and warm temperate thorn steppe will emerge. The area proportion of warm temperate dry forest will expand from 12.2% to 22.8%–37.2%, while that of cool temperate moist forest will decrease from 18.5% to 6.9%–9.5%. The area proportion of cool temperate steppe will decrease from 51.8% to 34.5%–51.6%. Our results suggest that future climate change will be conducive to the growth and expansion of forest zones on the Loess Plateau, which can provide valuable reference information for regional vegetation restoration planning and adaptive strategies in this region.

Mapping SOC (Soil Organic Carbon) using LiDAR-derived vegetation indices in a random forest regression model

Science.gov (United States)

Will, R. M.; Glenn, N. F.; Benner, S. G.; Pierce, J. L.; Spaete, L.; Li, A.

2015-12-01

Quantifying SOC (Soil Organic Carbon) storage in complex terrain is challenging due to high spatial variability. Generally, the challenge is met by transforming point data to the entire landscape using surrogate, spatially-distributed, variables like elevation or precipitation. In many ecosystems, remotely sensed information on above-ground vegetation (e.g. NDVI) is a good predictor of below-ground carbon stocks. In this project, we are attempting to improve this predictive method by incorporating LiDAR-derived vegetation indices. LiDAR provides a mechanism for improved characterization of aboveground vegetation by providing structural parameters such as vegetation height and biomass. In this study, a random forest model is used to predict SOC using a suite of LiDAR-derived vegetation indices as predictor variables. The Reynolds Creek Experimental Watershed (RCEW) is an ideal location for a study of this type since it encompasses a strong elevation/precipitation gradient that supports lower biomass sagebrush ecosystems at low elevations and forests with more biomass at higher elevations. Sagebrush ecosystems composed of Wyoming, Low and Mountain Sagebrush have SOC values ranging from .4 to 1% (top 30 cm), while higher biomass ecosystems composed of aspen, juniper and fir have SOC values approaching 4% (top 30 cm). Large differences in SOC have been observed between canopy and interspace locations and high resolution vegetation information is likely to explain plot scale variability in SOC. Mapping of the SOC reservoir will help identify underlying controls on SOC distribution and provide insight into which processes are most important in determining SOC in semi-arid mountainous regions. In addition, airborne LiDAR has the potential to characterize vegetation communities at a high resolution and could be a tool for improving estimates of SOC at larger scales.

Occurrence and abundance of ants, reptiles, and mammals: Chapter 7

Science.gov (United States)

2011-01-01

Sagebrush (Artemisia spp.)- associated wildlife are threatened by habitat loss and fragmentation and by impacts associated with anthropogenic disturbances, including energy development. Understanding how species of concern as well as other wildlife including insects, reptiles, and mammals respond to type and spatial scale of disturbance is critical to managing future land uses and identifying sites that are important for conservation. We developed statistical models to describe species occurrence or abundance, based on area searches in 7.29-ha survey blocks, across the Wyoming Basins Ecoregional Assessment (WBEA) area for six shrub steppe-associated species: harvester ant (Pogonomyrmex spp.), thatch ant (Formica spp.), short-horned lizard (Phrynosoma hernandesi), white-tailed jackrabbit (Lepus townsendii), cottontail (Sylvilagus spp.) and least chipmunk (Tamius minimus). We modeled patterns in occupancy or abundance relative to multi-scale measures of vegetation type and pattern, abiotic site characteristics, and anthropogenic disturbance factors. Sagebrush habitat was a strong predictor of occurrence for shorthorned lizards and white-tailed jackrabbits, but weak for the other four species. Vegetation and abiotic characteristics were strong determinants of species occurrence, although the scale of response was not consistent among species. All species, with the exception of the short-horned lizard, responded to anthropogenic disturbance, although responses again varied as a function of scale and direction (negative and positive influences). Our results improve our understanding of how environmental and anthropogenic factors affect species distributions across the WBEA area and facilitate a multi-species approach to management of this sagebrush ecosystem.

Banking Wyoming big sagebrush seeds

Science.gov (United States)

Robert P. Karrfalt; Nancy Shaw

2013-01-01

Five commercially produced seed lots of Wyoming big sagebrush (Artemisia tridentata Nutt. var. wyomingensis (Beetle & Young) S.L. Welsh [Asteraceae]) were stored under various conditions for 5 y. Purity, moisture content as measured by equilibrium relative humidity, and storage temperature were all important factors to successful seed storage. Our results indicate...

Differential response of vegetation in Hulun Lake region at the northern margin of Asian summer monsoon to extreme cold events of the last deglaciation

Science.gov (United States)

Zhang, Shengrui; Xiao, Jule; Xu, Qinghai; Wen, Ruilin; Fan, Jiawei; Huang, Yun; Yamagata, Hideki

2018-06-01

The response of vegetation to extreme cold events during the last deglaciation is important for assessing the impact of possible extreme climatic events on terrestrial ecosystems under future global warming scenarios. Here, we present a detailed record of the development of regional vegetation in the northern margin of Asian summer monsoon during the last deglaciation (16,500-11,000 cal yr BP) based on a radiocarbon-dated high-resolution pollen record from Hulun Lake, northeast China. The results show that the regional vegetation changed from subalpine meadow-desert steppe to mixed coniferous and deciduous forest-typical steppe during the last deglaciation. However, its responses to the Heinrich event 1 (H1) and the Younger Dryas event (YD) were significantly different: during the H1 event, scattered sparse forest was present in the surrounding mountains, while within the lake catchment the vegetation cover was poor and was dominated by desert steppe. In contrast, during the YD event, deciduous forest developed and the proportion of coniferous forest increased in the mountains, the lake catchment was occupied by typical steppe. We suggest that changes in Northern Hemisphere summer insolation and land surface conditions (ice sheets and sea level) caused temperature and monsoonal precipitation variations that contributed to the contrasting vegetation response during the two cold events. We conclude that under future global warming scenarios, extreme climatic events may cause a deterioration of the ecological environment of the Hulun Lake region, resulting in increased coniferous forest and decreased total forest cover in the surrounding mountains, and a reduction in typical steppe in the lake catchment.

Impact of the invasive species Elaeagnus Angustifolia L. on vegetation in Pontic desert steppe zone (Southern Ukraine)

NARCIS (Netherlands)

Sudnik-Wojcikowska, B.; Moysiyenko, I.; Slim, P.A.; Moraczewski, I.R.

2009-01-01

The Irano-Turanian species – Russian olive (Elaeagnus angustifolia L.) – is one of most commonly planted tree in the shelterbelts in southern Ukraine. The consequences of introduction of the species from windbreaks, into areas of different land use in west and central Pontic desert steppe zone are

Scales of snow depth variability in high elevation rangeland sagebrush

Science.gov (United States)

Tedesche, Molly E.; Fassnacht, Steven R.; Meiman, Paul J.

2017-09-01

In high elevation semi-arid rangelands, sagebrush and other shrubs can affect transport and deposition of wind-blown snow, enabling the formation of snowdrifts. Datasets from three field experiments were used to investigate the scales of spatial variability of snow depth around big mountain sagebrush ( Artemisia tridentata Nutt.) at a high elevation plateau rangeland in North Park, Colorado, during the winters of 2002, 2003, and 2008. Data were collected at multiple resolutions (0.05 to 25 m) and extents (2 to 1000 m). Finer scale data were collected specifically for this study to examine the correlation between snow depth, sagebrush microtopography, the ground surface, and the snow surface, as well as the temporal consistency of snow depth patterns. Variograms were used to identify the spatial structure and the Moran's I statistic was used to determine the spatial correlation. Results show some temporal consistency in snow depth at several scales. Plot scale snow depth variability is partly a function of the nature of individual shrubs, as there is some correlation between the spatial structure of snow depth and sagebrush, as well as between the ground and snow depth. The optimal sampling resolution appears to be 25-cm, but over a large area, this would require a multitude of samples, and thus a random stratified approach is recommended with a fine measurement resolution of 5-cm.

Estimating vegetation biomass and cover across large plots in shrub and grass dominated drylands using terrestrial lidar and machine learning

Science.gov (United States)

Anderson, Kyle E.; Glenn, Nancy F.; Spaete, Lucas P.; Shinneman, Douglas; Pilliod, David S.; Arkle, Robert; McIlroy, Susan; Derryberry, DeWayne R.

2018-01-01

Terrestrial laser scanning (TLS) has been shown to enable an efficient, precise, and non-destructive inventory of vegetation structure at ranges up to hundreds of meters. We developed a method that leverages TLS collections with machine learning techniques to model and map canopy cover and biomass of several classes of short-stature vegetation across large plots. We collected high-definition TLS scans of 26 1-ha plots in desert grasslands and big sagebrush shrublands in southwest Idaho, USA. We used the Random Forests machine learning algorithm to develop decision tree models predicting the biomass and canopy cover of several vegetation classes from statistical descriptors of the aboveground heights of TLS points. Manual measurements of vegetation characteristics collected within each plot served as training and validation data. Models based on five or fewer TLS descriptors of vegetation heights were developed to predict the canopy cover fraction of shrubs (R2 = 0.77, RMSE = 7%), annual grasses (R2 = 0.70, RMSE = 21%), perennial grasses (R2 = 0.36, RMSE = 12%), forbs (R2 = 0.52, RMSE = 6%), bare earth or litter (R2 = 0.49, RMSE = 19%), and the biomass of shrubs (R2 = 0.71, RMSE = 175 g) and herbaceous vegetation (R2 = 0.61, RMSE = 99 g) (all values reported are out-of-bag). Our models explained much of the variability between predictions and manual measurements, and yet we expect that future applications could produce even better results by reducing some of the methodological sources of error that we encountered. Our work demonstrates how TLS can be used efficiently to extend manual measurement of vegetation characteristics from small to large plots in grasslands and shrublands, with potential application to other similarly structured ecosystems. Our method shows that vegetation structural characteristics can be modeled without classifying and delineating individual plants, a challenging and time-consuming step common in previous

Challenges of establishing big sgebrush (Artemisia tridentata) in rangeland restoration: effects of herbicide, mowing, whole-community seeding, and sagebrush seed sources

Science.gov (United States)

Brabec, Martha M.; Germino, Matthew J.; Shinneman, Douglas J.; Pilliod, David S.; McIlroy, Susan K.; Arkle, Robert S.

2015-01-01

The loss of big sagebrush (Artemisia tridentata Nutt.) on sites disturbed by fire has motivated restoration seeding and planting efforts. However, the resulting sagebrush establishment is often lower than desired, especially in dry areas. Sagebrush establishment may be increased by addressing factors such as seed source and condition or management of the plant community. We assessed initial establishment of seeded sagebrush and four populations of small outplants (from different geographies, climates, and cytotypes) and small sagebrush outplants in an early seral community where mowing, herbicide, and seeding of other native plants had been experimentally applied. No emergence of seeded sagebrush was detected. Mowing the site before planting seedlings led to greater initial survival probabilities for sagebrush outplants, except where seeding also occurred, and these effects were related to corresponding changes in bare soil exposure. Initial survival probabilities were > 30% greater for the local population of big sagebrush relative to populations imported to the site from typical seed transfer distances of ~320–800 km. Overcoming the high first-year mortality of outplanted or seeded sagebrush is one of the most challenging aspects of postfire restoration and rehabilitation, and further evaluation of the impacts of herb treatments and sagebrush seed sources across different site types and years is needed.

Restoring big sagebrush after controlling encroaching western juniper with fire: aspect and subspecies effects

Science.gov (United States)

The need for restoration of shrubs is increasingly recognized around the world. In the western USA, restoration of mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana (Rydb.) Beetle) after controlling encroaching conifers is a priority to improve sagebrush-associated wildlife habitat. ...

Steppe Eagle in the Karaganda Region, Kazakhstan

Directory of Open Access Journals (Sweden)

Igor V. Karyakin

2018-03-01

Full Text Available Between June 22 and July 18, 2017, fieldworks were carried out to study the population structure and demographic characteristics of the Steppe Eagle breeding groups (Aquila nipalensis in the central part of the Karaganda region of Kazakhstan. In the course of the work 808 birds we found, 280 Steppe Eagle breeding territories were localized. Within 10 registration areas 277 Steppe Eagle breeding territories (96.18 % were examined, including 70 successful nests with 102 nestlings. The occupation of breeding territories was 87.73 %, while the percentage of active nests in the occupied breeding territories was 69.14 %. Successful were 42.26 % of nests from the number of active nests and 25.63 % from the number of identified breeding territories. The number of nestlings in broods ranged from 1 to 3, averaging (n=71 1.45±0.56 nestlings per successful nest and (n=168 0.61±0.80 nestlings per occupied nest. With a very high percentage of nests with unsuccessful breeding (54.46 % of the number of active ones, high percentage of nests with dead clutch was recorded – 34.55 % of the number of nests with unsuccessful breeding. Distribution density of Steppe Eagle active nests averaged 7.67/100 km2, varying in different areas from 4.11 to 12.90/100 km2. The distribution density of Steppe Eagle successful nests on the areas varied from 0 to 4.81/100 km2 averaged 3.24/100 km2. For the area of habitats suitable for breeding across the Karaganda region (142,549.9 km2, the abundance of the Steppe Eagle in nesting was 4,794–5,814, at average 5,275 pairs and 2,183–2,647, at average 2,402 successful pairs.

Ecosystem responses to warming and watering in typical and desert steppes

Science.gov (United States)

Xu, Zhenzhu; Hou, Yanhui; Zhang, Lihua; Liu, Tao; Zhou, Guangsheng

2016-10-01

Global warming is projected to continue, leading to intense fluctuations in precipitation and heat waves and thereby affecting the productivity and the relevant biological processes of grassland ecosystems. Here, we determined the functional responses to warming and altered precipitation in both typical and desert steppes. The results showed that watering markedly increased the aboveground net primary productivity (ANPP) in a typical steppe during a drier year and in a desert steppe over two years, whereas warming manipulation had no significant effect. The soil microbial biomass carbon (MBC) and the soil respiration (SR) were increased by watering in both steppes, but the SR was significantly decreased by warming in the desert steppe only. The inorganic nitrogen components varied irregularly, with generally lower levels in the desert steppe. The belowground traits of soil total organic carbon (TOC) and the MBC were more closely associated with the ANPP in the desert than in the typical steppes. The results showed that the desert steppe with lower productivity may respond strongly to precipitation changes, particularly with warming, highlighting the positive effect of adding water with warming. Our study implies that the habitat- and year-specific responses to warming and watering should be considered when predicting an ecosystem’s functional responses under climate change scenarios.

Impacts of informal trails on vegetation and soils in the highest protected area in the Southern Hemisphere.

Science.gov (United States)

Barros, Agustina; Gonnet, Jorge; Pickering, Catherine

2013-09-30

There is limited recreation ecology research in South America, especially studies looking at informal trails. Impacts of informal trails formed by hikers and pack animals on vegetation and soils were assessed for the highest protected area in the Southern Hemisphere, Aconcagua Provincial Park. The number of braided trails, their width and depth were surveyed at 30 sites along the main access route to Mt Aconcagua (6962 m a.s.l.). Species composition, richness and cover were also measured on control and trail transects. A total of 3.3 ha of alpine meadows and 13.4 ha of alpine steppe were disturbed by trails. Trails through meadows resulted in greater soil loss, more exposed soil and rock and less vegetation than trails through steppe vegetation. Trampling also affected the composition of meadow and steppe vegetation with declines in sedges, herbs, grasses and shrubs on trails. These results highlight how visitor use can result in substantial cumulative damage to areas of high conservation value in the Andes. With unregulated use of trails and increasing visitation, park agencies need to limit the further spread of informal trails and improve the conservation of plant communities in Aconcagua Provincial Park and other popular parks in the region. Copyright © 2013 Elsevier Ltd. All rights reserved.

DEER BELIEF AND DEER SACRIFICE AROUND STEPPE CULTURE

Directory of Open Access Journals (Sweden)

Aslı KAHRAMAN ÇINAR

2016-04-01

Full Text Available Turkish people have spreaded on a large area historically. They have left a mark on all the places they reach. The history of Turks begun in Central Asian Steppes. In reaction to the steppe culture, the human communities of Turks are hunter-nomad communities. The hunter-nomad comminuties make a living from stockfarming and apiculture. The deer is one of the essential animals for t he hunter-nomad communities in the daily life. In the steppe, the deer is seen in all area of social life. Further, the deer motives are commonly used in political, military, financial, the most religious areas. The hunter-nomad comminuties benefit by the meat, milk, leather, horns, nails, etc of the deer. In this study, we dwell on the deer with regard to its intended purposes and usage areas according to steppe culture. The references of this study are references are inscriptions, mythologic stories and archeological datas.

Evaluating a seed technology for sagebrush restoration across an elevation gradient: support for bet hedging

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Big sagebrush (Artemisia tridentata Nutt.) restoration is needed across vast areas, especially after large wildfires, to restore important ecosystem services. Sagebrush restoration success is inconsistent with a high rate of seeding failures, particularly at lower elevations. Seed enhancement tech...

THE MOLDOVA VEGETATION EXPOSITION FROM THE BOTANICAL GARDEN OF THE ACADEMY OF SCIENCES OF MOLDOVA

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POSTOLACHE GHEORGHE

2007-12-01

Full Text Available Construction phases of the Moldova Vegetation Exposition from the Botanical Garden of Chişinău are presented. Twelve forest micro-expositions, one steppe vegetation exposition, one grassland micro-exposition and an area of rare plants have been created during last 35 year on an area of 14 ha. The Moldova Vegetation Exposition includes 400 species of vascular plants.

Fungal and bacterial contributions to nitrogen cycling in cheatgrass-invaded and uninvaded native sagebrush soils of the western USA

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DeCrappeo, Nicole; DeLorenze, Elizabeth J.; Giguere, Andrew T; Pyke, David A.; Bottomley, Peter J.

2017-01-01

AimThere is interest in determining how cheatgrass (Bromus tectorum L.) modifies N cycling in sagebrush (Artemisia tridentata Nutt.) soils of the western USA.MethodsTo gain insight into the roles of fungi and bacteria in N cycling of cheatgrass-invaded and uninvaded sagebrush soils, the fungal protein synthesis inhibitor, cycloheximide (CHX), and the bacteriocidal compound, bronopol (BRO) were combined with a 15NH4+ isotope pool dilution approach.ResultsCHX reduced gross N mineralization to the same rate in both sagebrush and cheatgrass soils indicating a role for fungi in N mineralization in both soil types. In cheatgrass soils BRO completely inhibited gross N mineralization, whereas, in sagebrush soils a BRO-resistant gross N mineralization rate was detected that was slower than CHX sensitive gross N mineralization, suggesting that the microbial drivers of gross N mineralization were different in sagebrush and cheatgrass soils. Net N mineralization was stimulated to a higher rate in sagebrush than in cheatgrass soils by CHX, implying that a CHX inhibited N sink was larger in the former than the latter soils. Initial gross NH4+ consumption rates were reduced significantly by both CHX and BRO in both soil types, yet, consumption rates recovered significantly between 24 and 48 h in CHX-treated sagebrush soils. The recovery of NH4+ consumption in sagebrush soils corresponded with an increase in the rate of net nitrification.ConclusionsThese results suggest that cheatgrass invasion of sagebrush soils of the northern Great Basin reduces the capacity of the fungal N consumption sink, enhances the capacity of a CHX resistant N sink and alters the contributions of bacteria and fungi to gross N mineralization.

Effects of using winter grazing as a fuel treatment on Wyoming big sagebrush plant communities

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More frequent wildfires and incidences of mega-fires have increased the pressure for fuel treatments in sagebrush (Artemisia) communities. Winter grazing has been one of many fuel treatments proposed for Wyoming big sagebrush (A. tridentata Nutt. subsp. wyomingensis Beetle and A. Young) communitie...

Systematic Mapping and Statistical Analyses of Valley Landform and Vegetation Asymmetries Across Hydroclimatic Gradients

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Poulos, M. J.; Pierce, J. L.; McNamara, J. P.; Flores, A. N.; Benner, S. G.

2015-12-01

Terrain aspect alters the spatial distribution of insolation across topography, driving eco-pedo-hydro-geomorphic feedbacks that can alter landform evolution and result in valley asymmetries for a suite of land surface characteristics (e.g. slope length and steepness, vegetation, soil properties, and drainage development). Asymmetric valleys serve as natural laboratories for studying how landscapes respond to climate perturbation. In the semi-arid montane granodioritic terrain of the Idaho batholith, Northern Rocky Mountains, USA, prior works indicate that reduced insolation on northern (pole-facing) aspects prolongs snow pack persistence, and is associated with thicker, finer-grained soils, that retain more water, prolong the growing season, support coniferous forest rather than sagebrush steppe ecosystems, stabilize slopes at steeper angles, and produce sparser drainage networks. We hypothesize that the primary drivers of valley asymmetry development are changes in the pedon-scale water-balance that coalesce to alter catchment-scale runoff and drainage development, and ultimately cause the divide between north and south-facing land surfaces to migrate northward. We explore this conceptual framework by coupling land surface analyses with statistical modeling to assess relationships and the relative importance of land surface characteristics. Throughout the Idaho batholith, we systematically mapped and tabulated various statistical measures of landforms, land cover, and hydroclimate within discrete valley segments (n=~10,000). We developed a random forest based statistical model to predict valley slope asymmetry based upon numerous measures (n>300) of landscape asymmetries. Preliminary results suggest that drainages are tightly coupled with hillslopes throughout the region, with drainage-network slope being one of the strongest predictors of land-surface-averaged slope asymmetry. When slope-related statistics are excluded, due to possible autocorrelation, valley

137 ancient human genomes from across the Eurasian steppes.

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Damgaard, Peter de Barros; Marchi, Nina; Rasmussen, Simon; Peyrot, Michaël; Renaud, Gabriel; Korneliussen, Thorfinn; Moreno-Mayar, J Víctor; Pedersen, Mikkel Winther; Goldberg, Amy; Usmanova, Emma; Baimukhanov, Nurbol; Loman, Valeriy; Hedeager, Lotte; Pedersen, Anders Gorm; Nielsen, Kasper; Afanasiev, Gennady; Akmatov, Kunbolot; Aldashev, Almaz; Alpaslan, Ashyk; Baimbetov, Gabit; Bazaliiskii, Vladimir I; Beisenov, Arman; Boldbaatar, Bazartseren; Boldgiv, Bazartseren; Dorzhu, Choduraa; Ellingvag, Sturla; Erdenebaatar, Diimaajav; Dajani, Rana; Dmitriev, Evgeniy; Evdokimov, Valeriy; Frei, Karin M; Gromov, Andrey; Goryachev, Alexander; Hakonarson, Hakon; Hegay, Tatyana; Khachatryan, Zaruhi; Khaskhanov, Ruslan; Kitov, Egor; Kolbina, Alina; Kubatbek, Tabaldiev; Kukushkin, Alexey; Kukushkin, Igor; Lau, Nina; Margaryan, Ashot; Merkyte, Inga; Mertz, Ilya V; Mertz, Viktor K; Mijiddorj, Enkhbayar; Moiyesev, Vyacheslav; Mukhtarova, Gulmira; Nurmukhanbetov, Bekmukhanbet; Orozbekova, Z; Panyushkina, Irina; Pieta, Karol; Smrčka, Václav; Shevnina, Irina; Logvin, Andrey; Sjögren, Karl-Göran; Štolcová, Tereza; Tashbaeva, Kadicha; Tkachev, Alexander; Tulegenov, Turaly; Voyakin, Dmitriy; Yepiskoposyan, Levon; Undrakhbold, Sainbileg; Varfolomeev, Victor; Weber, Andrzej; Kradin, Nikolay; Allentoft, Morten E; Orlando, Ludovic; Nielsen, Rasmus; Sikora, Martin; Heyer, Evelyne; Kristiansen, Kristian; Willerslev, Eske

2018-05-09

For thousands of years the Eurasian steppes have been a centre of human migrations and cultural change. Here we sequence the genomes of 137 ancient humans (about 1× average coverage), covering a period of 4,000 years, to understand the population history of the Eurasian steppes after the Bronze Age migrations. We find that the genetics of the Scythian groups that dominated the Eurasian steppes throughout the Iron Age were highly structured, with diverse origins comprising Late Bronze Age herders, European farmers and southern Siberian hunter-gatherers. Later, Scythians admixed with the eastern steppe nomads who formed the Xiongnu confederations, and moved westward in about the second or third century BC, forming the Hun traditions in the fourth-fifth century AD, and carrying with them plague that was basal to the Justinian plague. These nomads were further admixed with East Asian groups during several short-term khanates in the Medieval period. These historical events transformed the Eurasian steppes from being inhabited by Indo-European speakers of largely West Eurasian ancestry to the mostly Turkic-speaking groups of the present day, who are primarily of East Asian ancestry.

Pleistocene Park: the restoration of steppes as a tool to mitigate climate change through albedo effect

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Zimov, N.; Loranty, M. M.; Edgar, C.; Kropp, H.; Zimov, S. A.

2017-12-01

In the late Pleistocene, the world largest ecosystem was the mammoth steppe. It stretched from the Iberian Peninsula to Canada and from the New Siberian Islands to China. It was a highly productive steppe ecosystem with numerous predators and herbivores that maintained the dominance of grasslands. With the end of the Pleistocene, the climate warmed and humans entered Siberia and the Americas. The introduction of humans as predators in these regions led to the extinction of most large animals, and the further degradation of the steppes. Mosses, shrubs and larch forest soon replaced grasses and herbs. Pleistocene Park is an experiment conducted in the far north of Siberia; its main goal is to revive the extinct steppe ecosystem in the Arctic. This would increase the richness of the northern ecosystems and, bioproductivity, and through a series of ecological mechanisms help to mitigate climate change. To conduct the experiment, was fenced 2000 hectares of land, and continue the ongoing process of introducing animals that either lived on this territory in the past or that can adapt to the modern northern environment. Through grazing, animals slowly transform the vegetation, replacing mosses, shrubs, and trees with grasses and herbs. Here we present the effects grazing animals have on the albedo of the landscape. Several years of year-round measurement of albedo and incoming and reflected radiation conducted in the grasslands in the park indicate substantially higher albedo compared with most modern ecosystems like larch forest and shrublands. Since grasses are lighter than forest, they reflect a higher portion of energy back to space. Results indicate the most dramatic difference in reflected solar radiation is in April and early May. Grasslands covered with snow reflect most of the sun's energy, while dark stems of forests and shrubs absorb that energy and promote warming. We argue that large-scale promotion of highly productive steppes in the Arctic will

Holocene Vegetation Succession and Response to Climate Change on the South Bank of the Heilongjiang-Amur River, Mohe County, Northeast China

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Chao Zhao

2016-01-01

Full Text Available Pollen samples from peat sediments on the south bank of the Heilongjiang River in northern Northeast China (NE China were analyzed to reconstruct the historical response of vegetation to climate change since 7800 cal yr BP. Vegetation was found to have experienced five successions from cold-temperate mixed coniferous and broadleaved forest to forest-steppe, steppe-woodland, steppe, and finally meadow-woodland. From 7800 to 7300 cal yr BP, the study area was warmer than present, and Betula, Larix, and Picea-dominated mixed coniferous and broadleaved forests thrived. Two cooling events at 7300 cal yr BP and 4500 cal yr BP led to a decrease in Betula and other broadleaved forests, whereas herbs of Poaceae expanded, leading to forest-steppe and then steppe-woodland environments. After 2500 cal yr BP, reduced temperatures and a decrease in evaporation rates are likely to have resulted in permafrost expansion and surface ponding, with meadow and isolated coniferous forests developing a resistance to the cold-wet environment. The Holocene warm period in NE China (7800–7300 cal yr BP could have resulted in a strengthening of precipitation in northernmost NE China and encouraged the development of broadleaved forests.

Woody fuels reduction in Wyoming big sagebrush communities

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Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young) ecosystems historically have been subject to disturbances that reduce or remove shrubs primarily by fire, although insect outbreaks and disease have also been important. Depending on site productivity, fire return in...

[Relationships among leaf traits and their expression in different vegetation zones in Yanhe River basin, Northwest China].

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Guo, Ru; Wen, Zhong-ming; Wang, Hong-xia; Qi, De-hui

2015-12-01

This article selected zonal plant communities as the research objects in different vegetation zones in Yanhe River basin. We measured six leaf traits of the dominant species and main accompanying species in each community, and then analyzed the relationships and their changes along with environmental gradients between these traits in order to understand the plant adaptation strategies to the environment changes. The results showed that the specific leaf area was significantly negatively correlated to leaf tissue density, area-based leaf nitrogen and phosphorus concentrations, and significantly positively correlated to mass-based leaf phosphorus concentration. Both the scaling relationships among these traits and plant life strategies were different among the three vegetation zones, the scaling-dependent relationship between leaf tissue density and specific leaf area was stronger in steppe and forest-steppe zones than in forest zone, but the correlations among area-based leaf nitrogen/phosphorus concentrations and specific leaf area and leaf tissue density were more significant in forest zone than in steppe zone. In the arid grassland and forest-steppe zone, plants give priority to defensive and stress resistance strategies, and in relatively moist nutrient-rich forest zone, plants give priority to fast growth and resource optimization allocation strategies.

Facilitation and interference of seedling establishment by a native legume before and after wildfire.

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Goergen, Erin; Chambers, Jeanne C

2012-01-01

In semi-arid ecosystems, heterogeneous resources can lead to variable seedling recruitment. Existing vegetation can influence seedling establishment by modifying the resource and physical environment. We asked how a native legume, Lupinus argenteus, modifies microenvironments in unburned and burned sagebrush steppe, and if L. argenteus presence facilitates seedling establishment of native species and the non-native annual grass, Bromus tectorum. Field treatments examined mechanisms by which L. argenteus likely influences establishment: (1) live L. argenteus; (2) dead L. argenteus; (3) no L. argenteus; (4) no L. argenteus with L. argenteus litter; (5) no L. argenteus with inert litter; and (6) mock L. argenteus. Response variables included soil nitrogen, moisture, temperature, solar radiation, and seedling establishment of the natives Elymus multisetus and Eriogonum umbellatum, and non-native B. tectorum. In both unburned and burned communities, there was higher spring soil moisture, increased shade and reduced maximum temperatures under L. argenteus canopies. Adult L. argenteus resulted in greater amounts of soil nitrogen (N) only in burned sagebrush steppe, but L. argenteus litter increased soil N under both unburned and burned conditions. Although L. argenteus negatively affected emergence and survival of B. tectorum overall, its presence increased B. tectorum biomass and reproduction in unburned plots. However, L. argenteus had positive facilitative effects on size and survival of E. multisetus in both unburned and burned plots. Our study indicates that L. argenteus can facilitate seedling establishment in semi-arid systems, but net effects depend on the species examined, traits measured, and level of abiotic stress.

Big sagebrush (Artemisia tridentata) in a shifting climate context: Assessment of seedling responses to climate

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Martha A. Brabec

2014-01-01

The loss of big sagebrush (Artemisia tridentata) throughout the Great Basin Desert has motivated efforts to restore it because of fire and other disturbance effects on sagebrush-dependent wildlife and ecosystem function. Initial establishment is the first challenge to restoration, and appropriateness of seeds, climate, and weather variability are factors that may...

Quantifying pollen-vegetation relationships to reconstruct ancient forests using 19th-century forest composition and pollen data

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Dawson, Andria; Paciorek, Christopher J.; McLachlan, Jason S.; Goring, Simon; Williams, John W.; Jackson, Stephen T.

2016-04-01

Mitigation of climate change and adaptation to its effects relies partly on how effectively land-atmosphere interactions can be quantified. Quantifying composition of past forest ecosystems can help understand processes governing forest dynamics in a changing world. Fossil pollen data provide information about past forest composition, but rigorous interpretation requires development of pollen-vegetation models (PVMs) that account for interspecific differences in pollen production and dispersal. Widespread and intensified land-use over the 19th and 20th centuries may have altered pollen-vegetation relationships. Here we use STEPPS, a Bayesian hierarchical spatial PVM, to estimate key process parameters and associated uncertainties in the pollen-vegetation relationship. We apply alternate dispersal kernels, and calibrate STEPPS using a newly developed Euro-American settlement-era calibration data set constructed from Public Land Survey data and fossil pollen samples matched to the settlement-era using expert elicitation. Models based on the inverse power-law dispersal kernel outperformed those based on the Gaussian dispersal kernel, indicating that pollen dispersal kernels are fat tailed. Pine and birch have the highest pollen productivities. Pollen productivity and dispersal estimates are generally consistent with previous understanding from modern data sets, although source area estimates are larger. Tests of model predictions demonstrate the ability of STEPPS to predict regional compositional patterns.

Quantifying pollen-vegetation relationships to reconstruct ancient forests using 19th-century forest composition and pollen data

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Dawson, Andria; Paciorek, Christopher J.; McLachlan, Jason S.; Goring, Simon; Williams, John W.; Jackson, Stephen T.

2016-01-01

Mitigation of climate change and adaptation to its effects relies partly on how effectively land-atmosphere interactions can be quantified. Quantifying composition of past forest ecosystems can help understand processes governing forest dynamics in a changing world. Fossil pollen data provide information about past forest composition, but rigorous interpretation requires development of pollen-vegetation models (PVMs) that account for interspecific differences in pollen production and dispersal. Widespread and intensified land-use over the 19th and 20th centuries may have altered pollen-vegetation relationships. Here we use STEPPS, a Bayesian hierarchical spatial PVM, to estimate key process parameters and associated uncertainties in the pollen-vegetation relationship. We apply alternate dispersal kernels, and calibrate STEPPS using a newly developed Euro-American settlement-era calibration data set constructed from Public Land Survey data and fossil pollen samples matched to the settlement-era using expert elicitation. Models based on the inverse power-law dispersal kernel outperformed those based on the Gaussian dispersal kernel, indicating that pollen dispersal kernels are fat tailed. Pine and birch have the highest pollen productivities. Pollen productivity and dispersal estimates are generally consistent with previous understanding from modern data sets, although source area estimates are larger. Tests of model predictions demonstrate the ability of STEPPS to predict regional compositional patterns.

Carbon balance assessment of a natural steppe of southern Siberia by multiple constraint approach

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L. Belelli Marchesini

2007-08-01

Full Text Available Steppe ecosystems represent an interesting case in which the assessment of carbon balance may be performed through a cross validation of the eddy covariance measurements against ecological inventory estimates of carbon exchanges (Ehman et al., 2002; Curtis et al., 2002.

Indeed, the widespread presence of ideal conditions for the applicability of the eddy covariance technique, as vast and homogeneous grass vegetation cover over flat terrains (Baldocchi, 2003, make steppes a suitable ground to ensure a constrain to flux estimates with independent methodological approaches.

We report about the analysis of the carbon cycle of a true steppe ecosystem in southern Siberia during the growing season of 2004 in the framework of the TCOS-Siberia project activities performed by continuous monitoring of CO₂ fluxes at ecosystem scale by the eddy covariance method, fortnightly samplings of phytomass, and ingrowth cores extractions for NPP assessment, and weekly measurements of heterotrophic component of soil CO₂ effluxes obtained by an experiment of root exclusion.

The carbon balance of the monitored natural steppe was, according to micrometeorological measurements, a sink of carbon of 151.7±36.9 g C m⁻², cumulated during the growing season from May to September. This result was in agreement with the independent estimate through ecological inventory which yielded a sink of 150.1 g C m⁻² although this method was characterized by a large uncertainty (±130% considering the 95% confidence interval of the estimate. Uncertainties in belowground process estimates account for a large part of the error. Thus, in particular efforts to better quantify the dynamics of root biomass (growth and turnover have to be undertaken in order to reduce the uncertainties in the assessment of NPP. This assessment should be preferably based on the application of multiple methods, each one characterized by its

Ecosystem responses to warming and watering in typical and desert steppes

OpenAIRE

Zhenzhu Xu; Yanhui Hou; Lihua Zhang; Tao Liu; Guangsheng Zhou

2016-01-01

Global warming is projected to continue, leading to intense fluctuations in precipitation and heat waves and thereby affecting the productivity and the relevant biological processes of grassland ecosystems. Here, we determined the functional responses to warming and altered precipitation in both typical and desert steppes. The results showed that watering markedly increased the aboveground net primary productivity (ANPP) in a typical steppe during a drier year and in a desert steppe over two ...

Effect of summer fire on cursorial spider (Aranei and beetle (Coleoptera assemblages in meadow steppes of Central European Russia

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Polchaninova Nina

2016-12-01

Full Text Available Fire is an important structuring force for grassland ecosystems. Despite increased incidents of fire in European steppes, their impact on arthropod communities is still poorly studied. We assessed short-term changes in cursorial beetle and spider assemblages after a summer fire in the meadow steppe in Central European Russia. The responses of spider and beetle assemblages to the fire event were different. In the first post-fire year, the same beetle species dominated burnt and unburnt plots, the alpha-diversity of beetle assemblages was similar, and there were no pronounced changes in the proportions of trophic groups. Beetle species richness and activity density increased in the second post-fire year, while that of the spiders decreased. The spider alpha-diversity was lowest in the first post-fire year, and the main dominants were pioneer species. In the second year, the differences in spider species composition and activity density diminished. The main conclusion of our study is that the large-scale intensive summer fire caused no profound changes in cursorial beetle and spider assemblages of this steppe plot. Mitigation of the fire effect is explained by the small plot area, its location at the edge of the fire site and the presence of adjacent undisturbed habitats with herbaceous vegetation.

Enhancing Pre- and Post-Wildfire Vegetation Recovery and Understanding Feedbacks of Cheatgrass invasion Using NASA Earth Observations

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Olsen, N.; Counts, A.; Quistorff, C.; Ohr, C. A.; Toner, C.

2017-12-01

Increasing wildfire frequency and severity has emphasized the importance of post-wildfire recovery efforts in southern Idaho's sagebrush ecosystems. These changing fire regimes favor invasive grass species while hindering native sagebrush habitat regeneration, causing a positive feedback cycle of invasive growth - wildfires - invasive growth. Due to this undesirable process and anthropogenic influences, the sagebrush ecosystem is one of the most endangered in the US. In this project the NASA DEVELOP group of Pocatello, Idaho partnered with the Bureau of Land Management, Idaho Department of Fish and Game, and the US Department of Agriculture to characterize ecosystem recovery following the Crystal (2006), Henry Creek (2016), Jefferson (2010), and Soda (2015) wildfires. Determining vegetation cover heterogeneity and density can be time consuming and the factors affecting ecosystem recovery can be complex. In addition, restoration success is difficult to determine as vegetation composition is not often known prior to wildfire events and monitoring vegetation composition after restoration efforts can be resource intensive. These wildfires temporal monitoring consisted of 2001 to 2017 using NASA Earth observations such as Landsat 5 Thermal Mapper (TM), Landsat 8 Operational Land Imager (OLI), Terra Moderate Resolution Imaging Spectroradiometer (MODIS), and Shuttle Radar Topography Mission (SRTM) to determine the most significant factors of wildfire recovery and the influence targeted grazing could have for recovery. In addition, this project will include monitoring of invasive species propagation and whether spatial patterns or extents of the wildfire contribute to propagation. Understanding the key variables that made reseeding and natural recovery work in some areas, assessing why they failed in others, and identifying factors that made non-native propagation ideal are important issues for land managers in this region.

Conservation state of populations of rare plant species in highly transformed meadow steppes of Southern Opillya

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I. I. Dmytrash-Vatseba

2016-09-01

Full Text Available Degradation of natural habitats causes rapid extinction of rare plant populations. The diversity of rare plant species in the meadow steppes of Southern Opillya (Western Ukraine depends strongly on patch area, pasture digression of vegetation and a variety of eco-coenotical conditions. The main threats for the rare components of the meadow steppe flora are reduction of habitat and overgrazing. Spatial connections between sites are unable to support a constant rare plant population. The analysis of the composition of rare plant meadow-steppe species indicated that habitats with similar rare species composition usually have similar parameters of area, stages of pasture digression and eco-coenotical conditions. Spatial connectivity of patches does not ensure species similarity of rare components of the flora. Rare plant species were grouped according to their preferences for habitat , area and condition. In small patches subject to any stage of pasture digression grow populations of Adonis vernalis L., Pulsatilla patens (L. Mill., P. grandis Wender., Stipa capillata L., S. рennata L., Chamaecytisus blockianus (Pawł. Klásková etc. On the contrary, populations of other species (Carlina onopordifolia Besser. ex Szafer., Kuecz. et Pawł., Adenophora liliifolia (L. Ledeb. ex A. DC., Crambe tataria Sebeók, Euphorbia volhynica Besser ex Racib., Stipa tirsa Stev. etc. prefer large habitats, not changed by pasture digression. Prevention of reduction of rare species diversity requires preservation (also extension of patch area and regulation of grazing intensity.

Selecting sagebrush seed sources for restoration in a variable climate: ecophysiological variation among genotypes

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Germino, Matthew J.

2012-01-01

Big sagebrush (Artemisia tridentata) communities dominate a large fraction of the United States and provide critical habitat for a number of wildlife species of concern. Loss of big sagebrush due to fire followed by poor restoration success continues to reduce ecological potential of this ecosystem type, particularly in the Great Basin. Choice of appropriate seed sources for restoration efforts is currently unguided due to knowledge gaps on genetic variation and local adaptation as they relate to a changing landscape. We are assessing ecophysiological responses of big sagebrush to climate variation, comparing plants that germinated from ~20 geographically distinct populations of each of the three subspecies of big sagebrush. Seedlings were previously planted into common gardens by US Forest Service collaborators Drs. B. Richardson and N. Shaw, (USFS Rocky Mountain Research Station, Provo, Utah and Boise, Idaho) as part of the Great Basin Native Plant Selection and Increase Project. Seed sources spanned all states in the conterminous Western United States. Germination, establishment, growth and ecophysiological responses are being linked to genomics and foliar palatability. New information is being produced to aid choice of appropriate seed sources by Bureau of Land Management and USFS field offices when they are planning seed acquisitions for emergency post-fire rehabilitation projects while considering climate variability and wildlife needs.

Response of gross ecosystem productivity, light use efficiency, and water use efficiency of Mongolian steppe to seasonal variations in soil moisture

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Li, Sheng-Gong; Eugster, Werner; Asanuma, Jun; Kotani, Ayumi; Davaa, Gombo; Oyunbaatar, Dambaravjaa; Sugita, Michiaki

2008-03-01

The examination of vegetation productivity and use of light and water resources is important for understanding the carbon and water cycles in semiarid and arid environments. We made continuous measurements of carbon dioxide and water vapor fluxes over an arid steppe ecosystem in Mongolia by using the eddy covariance (EC) technique. These measurements allow an examination of EC-estimated gross ecosystem productivity (GEP), light use efficiency (LUE), and water use efficiency (WUE) of the steppe. Daily variations of GEP, LUE, and WUE were associated with daily variations of incident photosynthetically active radiation (PAR), ambient temperature (Ta), and vapor pressure deficit (VPD). The magnitudes of these variations were also dependent on canopy development. On the daily basis, GEP linearly correlated with evapotranspiration rate and PAR. LUE correlated positively with leaf area index, Ta, and soil moisture availability but negatively with the surface reflectivity for short-wave solar radiation. Throughout the growing season, both GEP and LUE responded strongly to precipitation-fed soil moisture in the top 20 cm of the soil. An examination of the responses of LUE and WUE to PAR under different soil moisture conditions shows that when soil water availability exceeded VPD, the steppe was most efficient in light use, whereas it was less efficient in water use. The multivariate analysis of variance also suggests that soil moisture availability, especially water status in the upper 20-cm soil layer with dense distribution of grass roots, is the most significant factor that governs GEP, WUE, and LUE. This study provides a preliminary assessment of the use of available water and light by the Mongolian arid steppe ecosystems under seasonally varying soil moisture conditions. A better understanding of these functional responses is required to predict how climate change may affect arid steppe ecosystems.

Is fire exclusion in mountain big sagebrush communities prudent? Soil nutrient, plant diversity, and arthropod response to burning

Science.gov (United States)

Fire has largely been excluded from many mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana (Rydb.) Beetle) communities. Land and wildlife managers are especially reluctant to reintroduce fire in mountain big sagebrush plant communities, especially those communities without significan...

Natural concentrations of Pb/sup 210/ and Po/sup 210/ in plants of steppe phytocoenoses

Energy Technology Data Exchange (ETDEWEB)

Ladinskaya, L A; Parfenov, Yu D; Arutyunov, P S; Popov, D K [Leningradskij Inst. Radiatsionnoj Gigieny (USSR)

1976-01-01

Data are presented on the concentration of /sup 210/Pb and /sup 210/Po in summer vegetation in the aerial and root parts of sown fodder crops from steppes, saline meadows and marshy meadows and also in the leaves and branches of trees and bushes. The average concentrations of /sup 110/Pb and /sup 210/Po in the plants of individual communities have been evaluated, together with the /sup 210/Po//sup 210/Pb ratios in the aerial parts and roots and the accumulation coefficients. The variation distribution of the /sup 210/Po and /sup 210/Pb concentrations follows a log-normal law.

Modulation of Fire Regimes by Vegetation and Site Type in Southwestern Patagonia Since 13 ka

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Patricio I. Moreno

2018-04-01

Full Text Available The degree to which vegetation and site type have influenced fire regimes through the Holocene has not been investigated in detail in the temperate ecosystems of southern Patagonia. Here we present a first attempt using a paired-basin approach to study the evolution of fire regimes in sectors dominated by humid Nothofagus forests and the xeric Patagonian steppe in the Magallanes region of Chilean Patagonia (51°S. We analyzed sediment cores from two small lakes and a bog located within the same climate zone on opposite sides of the forest-steppe ecotone, ~28 km apart. The position of this biological boundary east of the Andes is controlled by the strength and position of the southern westerly winds, which constitute the sole source of precipitation throughout western Patagonia. Our results indicate that fires have occurred in the study region repeated times over the last ~13,000 years at bi- and tridecadal timescales. Sectors currently dominated by Patagonian steppe feature high frequency and low magnitude of local fires, and vice versa in humid forests. Climate-driven expansion of Nothofagus scrubland/woodland into steppe environments over the last ~4,200 years increased the magnitude and lowered the frequency of fire events, culminating with peak Nothofagus abundance, fire magnitude and frequency during the last millennium. We also detect divergences between lake-based vs. bog-based paleofire histories among paired sites located within the Patagonian steppe, ~12 km apart, which we attribute to local burning of the bog at times of lowered water table. This divergence suggests to us that bog-based vegetation and fire histories exacerbate a local, azonal, signal blurring extra-local or regional regimes, thus accounting for some discrepancies in the Quaternary paleovegetation/paleoclimate literature of southern Patagonia.

Multi-scale remote sensing sagebrush characterization with regression trees over Wyoming, USA: laying a foundation for monitoring

Science.gov (United States)

Homer, Collin G.; Aldridge, Cameron L.; Meyer, Debra K.; Schell, Spencer J.

2012-01-01

agebrush ecosystems in North America have experienced extensive degradation since European settlement. Further degradation continues from exotic invasive plants, altered fire frequency, intensive grazing practices, oil and gas development, and climate change – adding urgency to the need for ecosystem-wide understanding. Remote sensing is often identified as a key information source to facilitate ecosystem-wide characterization, monitoring, and analysis; however, approaches that characterize sagebrush with sufficient and accurate local detail across large enough areas to support this paradigm are unavailable. We describe the development of a new remote sensing sagebrush characterization approach for the state of Wyoming, U.S.A. This approach integrates 2.4 m QuickBird, 30 m Landsat TM, and 56 m AWiFS imagery into the characterization of four primary continuous field components including percent bare ground, percent herbaceous cover, percent litter, and percent shrub, and four secondary components including percent sagebrush (Artemisia spp.), percent big sagebrush (Artemisia tridentata), percent Wyoming sagebrush (Artemisia tridentata Wyomingensis), and shrub height using a regression tree. According to an independent accuracy assessment, primary component root mean square error (RMSE) values ranged from 4.90 to 10.16 for 2.4 m QuickBird, 6.01 to 15.54 for 30 m Landsat, and 6.97 to 16.14 for 56 m AWiFS. Shrub and herbaceous components outperformed the current data standard called LANDFIRE, with a shrub RMSE value of 6.04 versus 12.64 and a herbaceous component RMSE value of 12.89 versus 14.63. This approach offers new advancements in sagebrush characterization from remote sensing and provides a foundation to quantitatively monitor these components into the future.

The effects of climate, permafrost and fire on vegetation change in Siberia in a changing climate

Energy Technology Data Exchange (ETDEWEB)

Tchebakova, N M; Parfenova, E [V N Sukachev Institute of Forest, Siberian Branch of the Russian Academy of Sciences, Academgorodok, Krasnoyarsk, 660036 (Russian Federation); Soja, A J, E-mail: ncheby@forest.akadem.r, E-mail: Amber.J.Soja@nasa.go [National Institute of Aerospace (NIA), NASA Langley Research Center, Climate Sciences, 21 Langley Boulevard, Mail Stop 420, Hampton, VA 23681-2199 (United States)

2009-10-15

Observations and general circulation model projections suggest significant temperature increases in Siberia this century that are expected to have profound effects on Siberian vegetation. Potential vegetation change across Siberia was modeled, coupling our Siberian BioClimatic Model with several Hadley Centre climate change scenarios for 2020, 2050 and 2080, with explicit consideration of permafrost and fire activity. In the warmer and drier climate projected by these scenarios, Siberian forests are predicted to decrease and shift northwards and forest-steppe and steppe ecosystems are predicted to dominate over half of Siberia due to the dryer climate by 2080. Despite the large predicted increases in warming, permafrost is not predicted to thaw deep enough to sustain dark (Pinus sibirica, Abies sibirica, and Picea obovata) taiga. Over eastern Siberia, larch (Larix dahurica) taiga is predicted to continue to be the dominant zonobiome because of its ability to withstand continuous permafrost. The model also predicts new temperate broadleaf forest and forest-steppe habitats by 2080. Potential fire danger evaluated with the annual number of high fire danger days (Nesterov index is 4000-10 000) is predicted to increase by 2080, especially in southern Siberia and central Yakutia. In a warming climate, fuel load accumulated due to replacement of forest by steppe together with frequent fire weather promotes high risks of large fires in southern Siberia and central Yakutia, where wild fires would create habitats for grasslands because the drier climate would no longer be suitable for forests.

Climate effects on vegetation vitality at the treeline of boreal forests of Mongolia

Science.gov (United States)

Klinge, Michael; Dulamsuren, Choimaa; Erasmi, Stefan; Nikolaus Karger, Dirk; Hauck, Markus

2018-03-01

In northern Mongolia, at the southern boundary of the Siberian boreal forest belt, the distribution of steppe and forest is generally linked to climate and topography, making this region highly sensitive to climate change and human impact. Detailed investigations on the limiting parameters of forest and steppe in different biomes provide necessary information for paleoenvironmental reconstruction and prognosis of potential landscape change. In this study, remote sensing data and gridded climate data were analyzed in order to identify main distribution patterns of forest and steppe in Mongolia and to detect environmental factors driving forest development. Forest distribution and vegetation vitality derived from the normalized differentiated vegetation index (NDVI) were investigated for the three types of boreal forest present in Mongolia (taiga, subtaiga and forest-steppe), which cover a total area of 73 818 km2. In addition to the forest type areas, the analysis focused on subunits of forest and nonforested areas at the upper and lower treeline, which represent ecological borders between vegetation types. Climate and NDVI data were analyzed for a reference period of 15 years from 1999 to 2013. The presented approach for treeline delineation by identifying representative sites mostly bridges local forest disturbances like fire or tree cutting. Moreover, this procedure provides a valuable tool to distinguish the potential forested area. The upper treeline generally rises from 1800 m above sea level (a.s.l.) in the northeast to 2700 m a.s.l. in the south. The lower treeline locally emerges at 1000 m a.s.l. in the northern taiga and rises southward to 2500 m a.s.l. The latitudinal gradient of both treelines turns into a longitudinal one on the eastern flank of mountain ranges due to higher aridity caused by rain-shadow effects. Less productive trees in terms of NDVI were identified at both the upper and lower treeline in relation to the respective total boreal forest

The long-term trends (1982-2006) in vegetation greenness of the alpine ecosystem in the Qinghai-Tibetan Plateau

Science.gov (United States)

Zhang, Li; Guo, Huadong; Wang, Cuizhen; Ji, Lei; Li, Jing; Wang, Kun; Dai, Lin

2014-01-01

The increased rate of annual temperature in the Qinghai-Tibetan Plateau exceeded all other areas of the same latitude in recent decades. The influence of the warming climate on the alpine ecosystem of the plateau was distinct. An analysis of alpine vegetation under changes in climatic conditions was conducted in this study. This was done through an examination of vegetation greenness and its relationship with climate variability using the Advanced Very High Resolution Radiometer satellite imagery and climate datasets. Vegetation in the plateau experienced a positive trend in greenness, with 18.0 % of the vegetated areas exhibiting significantly positive trends, which were primarily located in the eastern and southwestern parts of the plateau. In grasslands, 25.8 % of meadows and 14.1 % of steppes exhibited significant upward trends. In contrast, the broadleaf forests experienced a trend of degradation. Temperature, particularly summer temperature, was the primary factor promoting the vegetation growth in the plateau. The wetter and warmer climate in the east contributed to the favorable conditions for vegetation. The alpine meadow was mostly sensitive to temperature, while the steppes were sensitive to both temperature and precipitation. Although a warming climate was expected to be beneficial to vegetation growth in the alpine region, the rising temperature coupled with reduced precipitation in the south did not favor vegetation growth due to low humidity and poor soil moisture conditions.

Models for predicting fuel consumption in sagebrush-dominated ecosystems

Science.gov (United States)

Clinton S. Wright

2013-01-01

Fuel consumption predictions are necessary to accurately estimate or model fire effects, including pollutant emissions during wildland fires. Fuel and environmental measurements on a series of operational prescribed fires were used to develop empirical models for predicting fuel consumption in big sagebrush (Artemisia tridentate Nutt.) ecosystems....

Effects of Water and Nitrogen Addition on Ecosystem Carbon Exchange in a Meadow Steppe

Science.gov (United States)

Wang, Yunbo; Jiang, Qi; Yang, Zhiming; Sun, Wei; Wang, Deli

2015-01-01

A changing precipitation regime and increasing nitrogen deposition are likely to have profound impacts on arid and semiarid ecosystem C cycling, which is often constrained by the timing and availability of water and nitrogen. However, little is known about the effects of altered precipitation and nitrogen addition on grassland ecosystem C exchange. We conducted a 3-year field experiment to assess the responses of vegetation composition, ecosystem productivity, and ecosystem C exchange to manipulative water and nitrogen addition in a meadow steppe. Nitrogen addition significantly stimulated aboveground biomass and net ecosystem CO2 exchange (NEE), which suggests that nitrogen availability is a primary limiting factor for ecosystem C cycling in the meadow steppe. Water addition had no significant impacts on either ecosystem C exchange or plant biomass, but ecosystem C fluxes showed a strong correlation with early growing season precipitation, rather than whole growing season precipitation, across the 3 experimental years. After we incorporated water addition into the calculation of precipitation regimes, we found that monthly average ecosystem C fluxes correlated more strongly with precipitation frequency than with precipitation amount. These results highlight the importance of precipitation distribution in regulating ecosystem C cycling. Overall, ecosystem C fluxes in the studied ecosystem are highly sensitive to nitrogen deposition, but less sensitive to increased precipitation. PMID:26010888

Soil nitrogen availability in the open steppe with Stipa tenacissima

Science.gov (United States)

Novosadova, Irena; Damian Ruiz Sinoga, Jose; Záhora, Jaroslav

2010-05-01

Open steppes dominated by Stipa tenacissima L. constitute one of the most representative ecosystems of the semi-arid zones of Iberian Peninsula and show a higher degree of variability in composition and structure (Maestre et al., 2007). Vegetation patchiness, which are seen as mosaics including vegetated and non-vegetated components, is a common feature of such open steppes (Valentin et al., 1999). Ecosystem functioning is strongly related to the spatial pattern of grass tussocks. Soils beneath S. tenacissima grass show higher fertility and improved microclimatic conditions, favouring the formation of "resource islands" (Maestre et al., 2007). First, soil moisture is greater beneath the clumps, due to water harvesting through rainfall interception, uptake by roots from adjacent unvegetated areas and water redistribution from gaps to clumps (Bergkamp et al., 1999; Puigdefá bregas et al., 1999). Second, the canopy diminishes the intense solar radiation (Maestre et al., 2001) avoiding the sun-baking effect, which is an important factor for soil temperature change and physical disruption (Magid et al., 1999). Plant clumps either functioned as microbial hotspots where enhanced microbially driven ecosystem processes took place or as microbial banks capable of undergoing a burst of activity under favourable climatic conditions (Goberna et al., 2007). The competition for water and resources between plants and microorganisms is strong and mediated trough an enormous variety of exudates and resource depletion intended to regulate soil microbial communities in the rhizosphere, control herbivory, encourage beneficial symbioses, and change chemical and physical properties in soil (Pugnaire et Armas, 2008). On the other hand there exists experimental evidence of a non-patchy distribution of certain soil microbial properties in semi-arid Mediterranean patchy ecosystems (Goberna et al., 2007). The microbial nutrient release processes have a fundamental role in ecosystem

78 FR 21964 - Sheldon National Wildlife Refuge Humboldt and Washoe Counties, NV, and Lake County, OR; Record of...

Science.gov (United States)

2013-04-12

... National Wildlife Refuge Complex, P.O. Box 111, Lakeview, OR 97630. Fax: (541) 947-4414. In-person viewing... Refuge encompasses 575,000 acres of sagebrush-steppe habitat located in a remote area of northwest Nevada... management would continue, with the following key enhancements. Native habitat conditions would improve, by...

A VEGETATION ISLAND WITH WHITE OAK (QUERCUS PUBESCENS WILLD. IN THE SUB-CARPATHIANS OF BUZĂU

Directory of Open Access Journals (Sweden)

ŞTEFAN NICOLAE

2007-12-01

Full Text Available The vegetation of a forest-steppe type from a part of the river Buzău Basin is presented in this paper. After a short presentation of the natural conditions of the forest Crivineni (near the village Valea Lupului, Buzău county, we are making an analysis of the present-day vegetation, as well as the coenotaxons identified by us in that forest.

Climatically driven loss of calcium in steppe soil as a sink for atmospheric carbon

Science.gov (United States)

A.G. Lapenis; G.B. Lawrence; S.W. Bailey; B.F. Aparin; A.I. Shiklomanov; N.A. Speranskaya; M.S. Torn; M. Calef

2008-01-01

During the last several thousand years the semi-arid, cold climate of the Russian steppe formed highly fertile soils rich in organic carbon and calcium (classified as Chernozems in the Russian system). Analysis of archived soil samples collected in Kemannaya Steppe Preserve in 1920, 1947, 1970, and fresh samples collected in 1998 indicated that the native steppe...

Insights into Penultimate Interglacial-Glacial Climate Change on Vegetation History at Lake Van, Turkey

Science.gov (United States)

Pickarski, N.; Litt, T.

2017-12-01

A new detailed pollen and oxygen isotope record of the penultimate interglacial-glacial cycle (ca. 250-129 ka; MIS 7-6), has been generated from the sediment core at Lake Van, Turkey. The integration of all available proxies (pollen, microscopic charcoal, δ18Obulk, and XRF) shows three temperate intervals of high effective soil moisture availability. This is evidenced by the predominance of oak steppe-forested landscapes similar to the present interglacial vegetation in this sensitive semiarid region. The wettest/warmest stage, as indicated by highest temperate tree percentages, can be broadly correlated with MIS 7c, while the amplitude of the tree population maximum during the oldest penultimate interglacial (MIS 7e) appears to be reduced due to warm but drier climatic conditions. A detailed comparison of the penultimate interglacial complex (MIS 7) to the last interglacial (MIS 5e) and the current interglacial (MIS 1) provides a vivid illustration of possible differences in the successive climatic cycles. Intervening periods of treeless vegetation (MIS 7d, 7a) were predominated by steppe elements. The occurrence of Artemisia and Chenopodiaceae during MIS 7d indicates very dry and cold climatic conditions, while higher temperate tree percentages (mainly deciduous Quercus) points to relatively humid and mild conditions throughout MIS 7b. Despite the general dominance of dry and cold desert-steppe vegetation during the penultimate glacial (MIS 6), this period can be divided into two parts: an early stage (ca. 193-157 ka) with higher oscillations in tree percentages and a later stage (ca. 157-131 ka) with lower tree percentages and subdued oscillations. Furthermore, we are able to identify the MIS 6e event (ca. 179-159 ka), which reveals clear climate variability due to rapid alternation in the vegetation cover. In comparison with long European pollen archives, speleothem isotope records from the Near East, and global climate parameters, the new high

A higher-level classification of the Pannonian and western Pontic steppe grasslands (Central and Eastern Europe).

Science.gov (United States)

Willner, Wolfgang; Kuzemko, Anna; Dengler, Jürgen; Chytrý, Milan; Bauer, Norbert; Becker, Thomas; Biţă-Nicolae, Claudia; Botta-Dukát, Zoltán; Čarni, Andraž; Csiky, János; Igić, Ruzica; Kącki, Zygmunt; Korotchenko, Iryna; Kropf, Matthias; Krstivojević-Ćuk, Mirjana; Krstonošić, Daniel; Rédei, Tamás; Ruprecht, Eszter; Schratt-Ehrendorfer, Luise; Semenishchenkov, Yuri; Stančić, Zvjezdana; Vashenyak, Yulia; Vynokurov, Denys; Janišová, Monika

2017-01-01

What are the main floristic patterns in the Pannonian and western Pontic steppe grasslands? What are the diagnostic species of the major subdivisions of the class Festuco-Brometea (temperate Euro-Siberian dry and semi-dry grasslands)? Carpathian Basin (E Austria, SE Czech Republic, Slovakia, Hungary, Romania, Slovenia, N Croatia and N Serbia), Ukraine, S Poland and the Bryansk region of W Russia. We applied a geographically stratified resampling to a large set of relevés containing at least one indicator species of steppe grasslands. The resulting data set of 17 993 relevés was classified using the TWINSPAN algorithm. We identified groups of clusters that corresponded to the class Festuco-Brometea . After excluding relevés not belonging to our target class, we applied a consensus of three fidelity measures, also taking into account external knowledge, to establish the diagnostic species of the orders of the class. The original TWINSPAN divisions were revised on the basis of these diagnostic species. The TWINSPAN classification revealed soil moisture as the most important environmental factor. Eight out of 16 TWINSPAN groups corresponded to Festuco-Brometea . A total of 80, 32 and 58 species were accepted as diagnostic for the orders Brometalia erecti , Festucetalia valesiacae and Stipo-Festucetalia pallentis , respectively. In the further subdivision of the orders, soil conditions, geographic distribution and altitude could be identified as factors driving the major floristic patterns. We propose the following classification of the Festuco-Brometea in our study area: (1) Brometalia erecti (semi-dry grasslands) with Scabioso ochroleucae-Poion angustifoliae (steppe meadows of the forest zone of E Europe) and Cirsio-Brachypodion pinnati (meadow steppes on deep soils in the forest-steppe zone of E Central and E Europe); (2) Festucetalia valesiacae (grass steppes) with Festucion valesiacae (grass steppes on less developed soils in the forest-steppe zone of E Central

Investigation of Great Basin big sagebrush and black greasewood as biogeochemical indicators of uranium mineralization. Final report. National Uranium Resource Evaluation

International Nuclear Information System (INIS)

Diebold, F.E.; McGrath, S.

1982-11-01

The effects of varying phosphate concentrations in natural aqueous systems upon the uptake of uranium by big sagebrush (Artemesia tridentata subsp. tridentata) and black greasewood (Sarcobatus vermiculatus (Hook) Torr.) were investigated. Two separate growth experiments with five drip-flow hyroponic units were used and plant seedlings were grown for 60 days in solutions of varying phosphate and uranium concentrations. Successful growth experiments were obtained only for big sagebrush; black greasewood did not sustain sufficient growth. The phosphate concentration of the water did affect the uptake of uranium by the big sagebrush, and this effect is most pronounced in the region of higher concentrations of uranium in the water. The ratio of the concentration of uranium in the plant to that in the water was observed to decrease with increasing uranium concentration in solution. This is indicative of an absorption barrier in the plants. The field data shows that big sagebrush responds to uranium concentrations in the soil water and not the groundwater. The manifestation of these results is that the use of big sagebrush as a biogeochemical indicator of uranium is not recommended. Since the concentration of phosphate must also be knwon in the water supplying the uranium to the plant, one should analyze this natural aqueous phase as a hydrochemical indicator rather than the big sagebrush

MODEL RECONSTRUCTION OF THE VEGETATION COVER OF THE SOUTH OF THE WEST SIBERIAN PLAIN FROM THE LATE PALEOLITHIC PERIOD UNTIL THE LATE XIX CENTURY

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М. А. Kharitonenkov

2016-06-01

Full Text Available Model reconstruction of vegetation cover of the south of the West Siberian Plain from the late Pleistocene to the modern era has been carried out on the basis of the associated chronological analysis of paleontological, archaeological and paleoclimate data. We have determined the starting point of active vegetation transformation in the south of the West Siberian Plain as a result of tradition-bound exploitation of natural resources. Periods of maximum anthropogenic load – peak and relative recession – on vegetation cover, acting as a further determinant factor, have been determined in this study for the first time. Comprehensive analysis and new understanding of palynological, paleozoological, archaeological and paleoclimate data in terms of theoretical synecology confirmed the notions on the determinant role of the anthropogenic factor in the transformation of the Pleistocene forest-meadow-steppe vegetation into contemporary communities of the southern taiga, the subtaiga and the forest-steppe of the West Siberian Plain.

Effects of feral free-roaming horses on semi-arid rangeland ecosystems: an example from the sagebrush steppe

Science.gov (United States)

Feral horses (Equus caballus) are viewed as a symbol of freedom and power; however, they are also a largely unmanaged, non-native grazer in North America, South America, and Australia. Information on their influence on vegetation and soil characteristics in semi-arid rangelands has been limited by ...

Grazing behavior and production characteristics among cows differing in residual feed intake while grazing late season Idaho rangeland

Science.gov (United States)

The objectives were to determine if cows classified as either low- or high-residual feed intake (LRFI or HRFI) differed in BW, BCS, and winter grazing activity over time. Thirty Hereford x Angus (LRFI = 16; HRFI = 14) 2-year-old cows grazed sagebrush-steppe for 78 d beginning 29 September 2016. Body...

Container configuration influences western larch and big sagebrush seedling development

Science.gov (United States)

Matthew Mehdi. Aghai

2012-01-01

Big sagebrush (Artemisia tridentata Nutt.), a woody shrub, and western larch (Larix occidentalis Nutt.), a deciduous conifer, are among many western North American species that have suffered a decline in presence and natural regeneration across their native ranges. These species are economically, ecologically, and intrinsically valuable, therefore many current...

Nesting pair density and abundance of ferruginous hawks (Buteo regalis) and golden eagles (Aquila chrysaetos) from aerial surveys in Wyoming

Science.gov (United States)

Lucretia E. Olson; Robert J. Oakleaf; John R. Squires; Zachary P. Wallace; Patricia L. Kennedy

2015-01-01

Raptors that inhabit sagebrush steppe and grassland ecosystems in the western United States may be threatened by continued loss and modification of their habitat due to energy development, conversion to agriculture, and human encroachment. Actions to protect these species are hampered by a lack of reliable data on such basic information as population size and...

Variation in ant populations with elevation, tree cover, and fire in a pinyon-juniper-dominated watershed

Science.gov (United States)

Eugenie M. MontBlanc; Jeanne C. Chambers; Peter E. Brussard

2007-01-01

Climate change and fire suppression have facilitated expansion of pinyon-juniper woodlands into sagebrush- steppe ecosystems of the Great Basin, USA, resulting in a loss of biological diversity. To assess the effects of using prescribed fire in restoration efforts, ant abundance, species richness, and composition were examined pre- and post-burn along the elevation and...

THE ROLE OF POLYPLOIDY IN ADAPTATION AND SETTLING OF STEPPE SHRUBS IN CENTRAL ASIA

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Natalia V Ekimova

2011-03-01

Full Text Available Chromosome numbers for some species of Central Asia steppe shrubs are given: Rhamnus erythroxylon Pall. (Rhamnaceae, Caragana buriatica Peschk. (Fabaceae, Amygdalus pedunculata Pall., Armeniaca sibirica (L. Lam. (Rosaceae, Atraphaxis pungens (Bieb. Jaub. et Spach. and A. frutescens (L. C. Koch (Polygonaceae. Chromosome numbers of some species were determined for the first time. Comparative analysis of adaptive properties of polyploid and diploid species has been conducted. It was established that natural polyploids are more adaptive to existence in extreme conditions. They possess by high potential for survival and characterized by more high level of intraspecific polymorphism, abundant flowering and fruitification, ability of propagate both generative and vegetative means, high seed germination.

Comparing the response of birds and butterflies to vegetation-based mountain ecotones using boundary detection approaches.

Science.gov (United States)

Kent, Rafi; Levanoni, Oded; Banker, Eran; Pe'er, Guy; Kark, Salit

2013-01-01

Mountains provide an opportunity to examine changes in biodiversity across environmental gradients and areas of transition (ecotones). Mountain ecotones separate vegetation belts. Here, we aimed to examine whether transition areas for birds and butterflies spatially correspond with ecotones between three previously described altitudinal vegetation belts on Mt. Hermon, northern Israel. These include the Mediterranean Maquis, xero-montane open forest and Tragacanthic mountain steppe vegetation belts. We sampled the abundance of bird and butterfly species in 34 sampling locations along an elevational gradient between 500 and 2200 m. We applied wombling, a boundary-detection technique, which detects rapid changes in a continuous variable, in order to locate the transition areas for bird and butterfly communities and compare the location of these areas with the location of vegetation belts as described in earlier studies of Mt. Hermon. We found some correspondence between the areas of transition of both bird and butterfly communities and the ecotones between vegetation belts. For birds and butterflies, important transitions occurred at the lower vegetation ecotone between Mediterranean maquis and the xero-montane open forest vegetation belts, and between the xero-montane open forest and the mountain steppe Tragacanthic belts. While patterns of species turnover with elevation were similar for birds and butterflies, the change in species richness and diversity with elevation differed substantially between the two taxa. Birds and butterflies responded quite similarly to the elevational gradient and to the shift between vegetation belts in terms of species turnover rates. While the mechanisms generating these patterns may differ, the resulting areas of peak turnover in species show correspondence among three different taxa (plants, birds and butterflies).

Climate effects on vegetation vitality at the treeline of boreal forests of Mongolia

Directory of Open Access Journals (Sweden)

M. Klinge

2018-03-01

Full Text Available In northern Mongolia, at the southern boundary of the Siberian boreal forest belt, the distribution of steppe and forest is generally linked to climate and topography, making this region highly sensitive to climate change and human impact. Detailed investigations on the limiting parameters of forest and steppe in different biomes provide necessary information for paleoenvironmental reconstruction and prognosis of potential landscape change. In this study, remote sensing data and gridded climate data were analyzed in order to identify main distribution patterns of forest and steppe in Mongolia and to detect environmental factors driving forest development. Forest distribution and vegetation vitality derived from the normalized differentiated vegetation index (NDVI were investigated for the three types of boreal forest present in Mongolia (taiga, subtaiga and forest–steppe, which cover a total area of 73 818 km2. In addition to the forest type areas, the analysis focused on subunits of forest and nonforested areas at the upper and lower treeline, which represent ecological borders between vegetation types. Climate and NDVI data were analyzed for a reference period of 15 years from 1999 to 2013. The presented approach for treeline delineation by identifying representative sites mostly bridges local forest disturbances like fire or tree cutting. Moreover, this procedure provides a valuable tool to distinguish the potential forested area. The upper treeline generally rises from 1800 m above sea level (a.s.l. in the northeast to 2700 m a.s.l. in the south. The lower treeline locally emerges at 1000 m a.s.l. in the northern taiga and rises southward to 2500 m a.s.l. The latitudinal gradient of both treelines turns into a longitudinal one on the eastern flank of mountain ranges due to higher aridity caused by rain-shadow effects. Less productive trees in terms of NDVI were identified at both the upper and lower treeline in relation

Strong genetic differentiation in the invasive annual grass Bromus tectorum across the Mojave-Great Basin ecological transition zone

Science.gov (United States)

Susan E. Meyer; Elizabeth A. Leger; Desiree R. Eldon; Craig E. Coleman

2016-01-01

Bromus tectorum, an inbreeding annual grass, is a dominant invader in sagebrush steppe habitat in North America. It is also common in warm and salt deserts, displaying a larger environmental tolerance than most native species. We tested the hypothesis that a suite of habitat-specific B. tectorum lineages dominates warm desert habitats. We sampled 30 B....

Microbial community responses to 17 years of altered precipitation are seasonally dependent and coupled to co-varying effects of water content on vegetation and soil C

Science.gov (United States)

Sorensen, Patrick O.; Germino, Matthew J.; Feris, Kevin P.

2013-01-01

Precipitation amount and seasonal timing determine the duration and distribution of water available for plant and microbial activity in the cold desert sagebrush steppe. In this study, we sought to determine if a sustained shift in the amount and timing of precipitation would affect soil microbial diversity, community composition, and soil carbon (C) storage. Field plots were irrigated (+200 mm) during the dormant or growing-season for 17 years. Microbial community responses were assessed over the course of a year at two depths (15–20 cm, 95–100 cm) by terminal restriction fragment length polymorphism (T-RFLP), along with co-occurring changes in plant cover and edaphic properties. Bacterial richness, Shannon Weaver diversity, and composition in shallow soils (15–20 cm) as well as evenness in deep soils (95–100 cm) differed across irrigation treatments during July. Irrigation timing affected fungal community diversity and community composition during the dormant season and most strongly in deep soils (95–100 cm). Dormant-season irrigation increased the ratio of shrubs to forbs and reduced soil C in shallow soils by 16% relative to ambient conditions. It is unclear whether or not soil C will continue to decline with continued treatment application or if microbial adaptation could mitigate sustained soil C losses. Future changes in precipitation timing will affect soil microbes in a seasonally dependent manner and be coupled to co-varying effects of water content on vegetation and soil C.

Narrow hybrid zone between two subspecies of big sagebrush (Artemisia tridentata: Asteraceae): XI. Plant-insect interactions in reciprocal transplant gardens

Science.gov (United States)

John H. Graham; E. Durant McArthur; D. Carl Freeman

2001-01-01

Basin big sagebrush (Artemisia tridentata ssp. tridentata) and mountain big sagebrush (A. t. ssp. vaseyana) hybridize in a narrow zone near Salt Creek, Utah. Reciprocal transplant experiments in this hybrid zone demonstrate that hybrids are more fit than either parental subspecies, but only in the hybrid zone. Do hybrids experience greater, or lesser, use by...

On the Succession of Sarmatian Population in the East-European Steppes

Directory of Open Access Journals (Sweden)

Balabanova Mariya A.

2016-06-01

Full Text Available As V.P. Alekseev wrote, the succession of population has been peculiar for individual territories for centuries. Despite the fact that the Eastern European steppe in ancient times and the Middle Ages was characterized by frequent changes of the population due to its high dependence on the environmental conditions, the Sarmatian culture preservation was observed over a period of ceremonial standards and elements of material culture. In this paper an attempt is made to show the presence of a partial succession of the three chronological periods of Sarmatian population. To do this, the author conducted a comparative characteristic of physical types of nomads of Sarmatian steppes of the Eastern Europe. The results of the study of mass craniological material combined in the cultural and chronological groups, showed that on the whole range of time and space over the steppe habitat Sarmatian cultures fixed partial similarity in physical type. In this connection, it is assumed that the partial continuity of anthropological types of different cultural, historical and local groups is linked to: 1 partial preservation of substrate Early Sarmatian population over the 4th- 3rd centuries BC – first half of 2nd-4th centuries AD; 2 the direction and character of penetration of nomadic groups who migrated from the East into steppe space; 3 design of a single system of seasonal migrations which involves the presence of winter and summer camps, and the presence of burial mounds; 4 the inclusion of a horde of nomadic pastoral population groups moved all over the steppes, from between Volga and Ural to the Lower Don; 5 the fact that male migrants married local women.

Outplanting Wyoming big sagebrush following wldfire: stock performance and economics

Science.gov (United States)

Dettweiler-Robinson, Eva; Bakker, Jonathan D.; Evans, James R.; Newsome, Heidi; Davies, G. Matt; Wirth, Troy A.; Pyke, David A.; Easterly, Richard T.; Salstrom, Debra; Dunwiddle, Peter W.

2013-01-01

Finding ecologically and economically effective ways to establish matrix species is often critical for restoration success. Wyoming big sagebrush (Artemisia tridentata subsp. wyomingensis) historically dominated large areas of western North America, but has been extirpated from many areas by large wildfires; its re-establishment in these areas often requires active management. We evaluated the performance (survival, health) and economic costs of container and bare-root stock based on operational plantings of more than 1.5 million seedlings across 2 200 ha, and compared our plantings with 30 other plantings in which sagebrush survival was tracked for up to 5 yr. Plantings occurred between 2001 and 2007, and included 12 combinations of stock type, planting amendment, and planting year.We monitored 10 500 plants for up to 8 yr after planting. Survival to Year 3 averaged 21% and was higher for container stock (30%) than bare-root stock (17%). Survival did not differ among container stock plantings, whereas survival of bare-root stock was sometimes enhanced by a hydrogel dip before planting, but not by

Bird-habitat relationships in interior Columbia Basin shrubsteppe

Science.gov (United States)

Earnst, S.L.; Holmes, A.L.

2012-01-01

Vegetation structure is considered an important habitat feature structuring avian communities. In the sagebrush biome, both remotely-sensed and field-acquired measures of big sagebrush (Artemisia tridentata) cover have proven valuable in understanding avian abundance. Differences in structure between the exotic annual cheatgrass (Bromus tectorum) and native bunchgrasses are also expected to be important. We used avian abundance data from 318 point count stations, coupled with field vegetation measurements and a detailed vegetation map, to model abundance for four shrub- and four grassland-associated avian species in southeastern Washington shrubsteppe. Specifically, we ask whether species distinguish between bunchgrass and cheatgrass, and whether mapped, categorical cover types adequately explain species' abundance or whether fine-grained, field-measured differences in vegetation cover are also important. Results indicate that mapped cover types alone can be useful for predicting patterns of distribution and abundance within the sagebrush biome for several avian species (five of eight studied here). However, field-measured sagebrush cover was a strong positive predictor for Sage Sparrow (Amphispiza belli), the only sagebrush obligate in this study, and a strong negative predictor for two grassland associates, Horned Lark (Eremophila alpestris) and Grasshopper Sparrow (Ammodramus savannarum). Likewise, shrub associates did not differ in abundance in sagebrush with a cheatgrass vs. bunchgrass understory, but grassland associates were more common in either bunchgrass (Horned Lark and Grasshopper Sparrow) or cheatgrass grasslands (Long-billed Curlew, Numenius americanus), or tended to use sagebrush-cheatgrass less than sagebrush-bunchgrass (Horned Lark, Grasshopper Sparrow, and Savannah Sparrow, Passerculus sandwichensis).

Quantifying restoration effectiveness using multi-scale habitat models: implications for sage-grouse in the Great Basin

Science.gov (United States)

Arkle, Robert S.; Pilliod, David S.; Hanser, Steven E.; Brooks, Matthew L.; Chambers, Jeanne C.; Grace, James B.; Knutson, Kevin C.; Pyke, David A.; Welty, Justin L.

2014-01-01

A recurrent challenge in the conservation of wide-ranging, imperiled species is understanding which habitats to protect and whether we are capable of restoring degraded landscapes. For Greater Sage-grouse (Centrocercus urophasianus), a species of conservation concern in the western United States, we approached this problem by developing multi-scale empirical models of occupancy in 211 randomly located plots within a 40 million ha portion of the species' range. We then used these models to predict sage-grouse habitat quality at 826 plots associated with 101 post-wildfire seeding projects implemented from 1990 to 2003. We also compared conditions at restoration sites to published habitat guidelines. Sage-grouse occupancy was positively related to plot- and landscape-level dwarf sagebrush (Artemisia arbuscula, A. nova, A. tripartita) and big sagebrush steppe prevalence, and negatively associated with non-native plants and human development. The predicted probability of sage-grouse occupancy at treated plots was low on average (0.09) and not substantially different from burned areas that had not been treated. Restoration sites with quality habitat tended to occur at higher elevation locations with low annual temperatures, high spring precipitation, and high plant diversity. Of 313 plots seeded after fire, none met all sagebrush guidelines for breeding habitats, but approximately 50% met understory guidelines, particularly for perennial grasses. This pattern was similar for summer habitat. Less than 2% of treated plots met winter habitat guidelines. Restoration actions did not increase the probability of burned areas meeting most guideline criteria. The probability of meeting guidelines was influenced by a latitudinal gradient, climate, and topography. Our results suggest that sage-grouse are relatively unlikely to use many burned areas within 20 years of fire, regardless of treatment. Understory habitat conditions are more likely to be adequate than overstory

Influence of shrubs on soil chemical properties in Alxa desert steppe, China

Science.gov (United States)

Hua Fu; Shifang Pei; Yaming Chen; Changgui Wan

2007-01-01

Alxa desert steppe is one of severely the degraded rangelands in the Northwest China. Shrubs, as the dominant life form in the desert steppe, play an important role in protecting this region from further desertification. Chemical properties of three soil layers (0 to 10, 10 to 20 and 20 to 30 cm) at three locations (the clump center [A], in the periphery of shrub...

Suitability of vegetation for erosion control on uranium mill tailings: a regional analysis

International Nuclear Information System (INIS)

Beedlow, P.A.; McShane, M.C.

1983-11-01

Inactive uranium mill tailings (UMTRAP sites) in the West were grouped into three major climatic regions to evaluate the adequacy of vegetation for long-term stabilization: the Colorado Plateau, the West Slope of the Rocky Mountains, and the Northern Great Plains. Four general vegetation types were found at western sites: grasslands, shrub-steppe, and saltshrub and woodland. Soil-loss rates, calculated using the Universal Soil Loss Equation, were variable within regions and vegetation types, but trends were apparent. Calculations indicated that vegetation or vegetation plus a layer of surface rock provided adequate stabilization against long-term average soil loss for slopes less than 10% at the UMTRAP sites evaluated. However, detailed analyses of erosion due to severe storm events, gully formation and channel cutting is necessary for designing protective covers at each site. 11 references, 3 figures, 3 tables

Response of soil methane uptake to simulated nitrogen deposition and grazing management across three types of steppe in Inner Mongolia, China.

Science.gov (United States)

Li, Xianglan; He, Hong; Yuan, Wenping; Li, Linghao; Xu, Wenfang; Liu, Wei; Shi, Huiqiu; Hou, Longyu; Chen, Jiquan; Wang, Zhiping

2018-01-15

The response of soil methane (CH 4 ) uptake to increased nitrogen (N) deposition and grazing management was studied in three types of steppe (i.e., meadow steppe, typical steppe, and desert steppe) in Inner Mongolia, China. The experiment was designed with four simulated N deposition rates such as 0, 50, 100, and 200kgNha -1 , respectively, under grazed and fenced management treatments. Results showed that the investigated steppes were significant sinks for CH 4 , with an uptake flux of 1.12-3.36kgha -1 over the grass growing season and that the magnitude of CH 4 uptake significantly (Prates. The soil CH 4 uptake rates were highest in the desert steppe, moderate in the typical steppe, and lowest in the meadow steppe. Compared with grazed plots, fencing increased the CH 4 uptake by 4.7-40.2% with a mean value of 20.2% across the three different steppe types. The responses of soil CH 4 uptake to N deposition in the continental steppe varied depending on the N deposition rate, steppe type, and grazing management. A significantly positive correlation between CH 4 uptake and soil temperature was found in this study, whereas no significant relationship between soil moisture and CH 4 uptake occurred. Our results may contribute to the improvement of model parameterization for simulating biosphere-atmosphere CH 4 exchange processes and for evaluating the climate change feedback on CH 4 soil uptake. Copyright © 2017 Elsevier B.V. All rights reserved.

Modeling responses of the meadow steppe dominated by Leymus chinensis to climate change

International Nuclear Information System (INIS)

Wang, Yuhui; Zhou, Guangsheng; Wang, Yonghe

2007-01-01

Grassland is one of the most widespread vegetation types worldwide and plays a significant role in regional climate and global carbon cycling. Understanding the sensitivity of Chinese grassland ecosystems to climate change and elevated atmospheric CO2 and the effect of these changes on the grassland ecosystems is a key issue in global carbon cycling. China encompasses vast grassland areas of 354 million ha of 17 major grassland types, according to a national grassland survey. In this study, a process-based terrestrial model the CENTURY model was used to simulate potential changes in net primary productivity (NPP) and soil organic carbon (SOC) of the Leymus chinensis meadow steppe (LCMS) under different scenarios of climatic change and elevated atmospheric CO2. The LCMS sensitivities, its potential responses to climate change, and the change in capacity of carbon stock and sequestration in the future are evaluated. The results showed that the LCMS NPP and SOC are sensitive to climatic change and elevated CO2. In the next 100 years, with doubled CO2 concentration, if temperature increases from 2.7-3.9C and precipitation increases by 10% NPP and SOC will increase by 7-21% and 5-6% respectively. However, if temperature increases by 7.5-7.8C and precipitation increases by only 10% NPP and SOC would decrease by 24% and 8% respectively. Therefore, changes in the NPP and SOC of the meadow steppe are attributed mainly to the amount of temperature and precipitation change and the atmospheric CO2 concentration in the future

Protocols for sagebrush seed processing and seedling production at the Lucky Peak Nursery

Science.gov (United States)

Clark D. Fleege

2010-01-01

This paper presents the production protocols currently practiced at the USDA Forest Service Lucky Peak Nursery (Boise, ID) for seed processing and bareroot and container seedling production for three subspecies of big sagebrush (Artemisia tridentata).

Quantifying Regional Vegetation Changes in China During Three Contrasting Warming Intervals since the Last Glacial Maximum

Science.gov (United States)

Li, Q.; Wu, H.; Yu, Y.; Sun, A.; Luo, Y.

2017-12-01

Reconstructing patterns of past vegetation change on a large-scale facilitates a better understanding of the interactions and feedbacks between climate change and the terrestrial biosphere. In addition, reducing the uncertainty in predictions of vegetation change under global warming highlights the importance of reconstructing vegetation patterns during past warming intervals. Here, we present a quantitative regional vegetation reconstruction for China during three intervals: Last Glacial Maximum (LGM, 18±2 14C kyr B.P.), early Holocene (8.5±0.5 14C kyr B.P.), and mid-Holocene (6±0.5 14C kyr B.P.). The biomization method, based on 249 pollen records, was used for the reconstructions. The results demonstrate that during the LGM, steppe and desert expanded eastwards and southwards, reaching the present-day temperate deciduous forest (TEDE) zone, and dominated northern China. In contrast, the forest in Eastern China underwent a substantial southwards retreat and the percentage of forest-type sites was at a minimum. In addition, the warm mixed forest (WAMF) and TEDE shifted southwards of 10° N relative to the present-day, and tropical seasonal rain forest (TSFO) was almost absent. At the same time, the forest-steppe boundary shifted southwards to near the middle and lower reaches of Yangtze River. For the early Holocene and mid-Holocene, the TSFO, WAMF, and TEDE shifted northwards by 2-5° relative to today, and the percentage of forest sites increased and reached a maximum in the mid-Holocene. The slight expansion of forest from the early Holocene to the mid-Holocene caused the forest-steppe boundary to shift northwestwards to near the present-day 300 mm isohyet by the mid-Holocene. Our results also indicate that climatic warming since the LGM, which strengthened the East Asian summer monsoon, favored the development of forest in China. This is potentially an important finding for evaluating the possible response of forest in China to future global warming.

Soils of the Pacific Northwest shrub-steppe. Occurrence and properties of soils on the Arid Land Ecology Reserve, Hanford Reservation

International Nuclear Information System (INIS)

Wildung, R.E.

1977-07-01

The soils of the Arid Land Ecology Reserve, encompassing the IBP Grassland Biome intensive study site on the ERDA Hanford Reservation, are representative of a larger geographical region including much of the Columbia Plateau and Pacific Northwest shrub-steppe. This results from a unique diversity in parent materials of mixed origin derived from the loess eolian, lacustrine and stream-laid material including glacial outwashes, river terraces, flood plains and alluvial fans and meteorological factors accompanying a marked change in altitude within the Reserve resulting in development of soils over a range in temperature, moisture and vegetative regimes. The Reserve and the IBP Grassland Biome intensive study site serve as valuable, representative areas for the study of soil genesis and morphology in the shrub-steppe. The role of soils can be determined in basic environmental processes involving the flow of energy, cyclization of nutrients or the fate and behavior of pollutants. These processes may be examined to provide baseline information for comparison to other, more disturbed areas. Or, for investigative purposes, processes may be systematically altered to determine the influence of soil-perturbing activities such as agriculture, mining and industry on the terrestrial ecosystem

Vegetation and climate history during the last millennium derived from Anggertu Lake, Tengger Desert

Science.gov (United States)

Duan, F.; An, C.; Zhao, Y.; Wang, W.; Cao, Z.

2017-12-01

Studying the climate changes during the last millennium can help us to understand current relationship between human-social activities and natural environment changes, and improve projections of future climate. Pollen assemblages, loss-on-ignition (LOIorg at 550 °C) and grain size data collected from sediment core (AGE15A) from the center of Anggertu lake (eastern Tengger Desert, Inner Mongolia) are presented to reconstruct regional vegetation and climate history during the last millennium. Results show that: 1) desert or desert steppe dominated by Artemisia and Amaranthaceae expanded around this region during the period of 988 1437 A.D., indicating a generally dry climate condition with two short humid periods (1003 1082 A.D. and 1388 1437 A.D). These two wet periods are characterized by relatively high vegetation cover and bio-productivity, reflected by high pollen concentrations and LOIorg. Increase in the steppe or meadow vegetation communities (Poaceae, Cyperaceae) and vegetation cover during the period of 1437 2015 A.D. suggest a wetting trend, as also indicated by gradually finer grain size. The relatively high LOI indicate a high bio-productivity during this interval. And then unstable lacustrine environment was found with frequent fluctuations in pollen concentration and grain size since 1842 A.D.. 2) This study recorded a relatively dry Medieval Warm Period (MWP; 1082 1388 A.D.) and a wet Little Ice Age (LIA; 1437 1842 A.D.), which is generally consistent with climate characteristics in arid central Asia (ACA). 3) Increased Amaranthaceae and high abundance of Poaceae were related to overgrazing and agricultural activities at that time to some extent. Thus vegetation evolution of the lake region was influenced by human activities and climate changes.

Identification, Classification, Mapping of Model and Secondary Steppe Ecosystems Within the Orenburg-Kazakhstan Cross-Border Region

Directory of Open Access Journals (Sweden)

Yakovlev Ilya Gennadyevich

2014-09-01

Full Text Available The article deals with the current issues of modern steppe management in the Orenburg-Kazakhstan cross-border region. The authors use the data of their own field research over the period of 2009-2014 aimed at detection and classification of model and secondary steppe ecosystems in the region. For the last 6 years it has been revealed that some steppe and fallow lands have different squares. The detected lands are multiple-aged and differ according to their qualitative composition depending on aged-specific (time for completion of agricultural activity, soil-lithogenous and floristic features.The authors detected sites of anthropogenic influence on steppe ecosystems as well as the factors that have favorable affect on restoration of natural ecosystems. The article also reveals the centers of restoration of traditional steppe fauna within the Orenburg-Kazakhstan region and the distribution area of marmot, little bustard, bustard, saiga antelope. The authors carried out the comparative analysis of agro-ecological situation in the region for a few last years as well as over long period of time according to archival and polling data.

Mountain big sagebrush age distribution and relationships on the northern Yellowstone Winter Range

Science.gov (United States)

Carl L. Wambolt; Trista L. Hoffman

2001-01-01

This study was conducted within the Gardiner Basin, an especially critical wintering area for native ungulates utilizing the Northern Yellowstone Winter Range. Mountain big sagebrush plants on 33 sites were classified as large (≥22 cm canopy cover), small (

Middle-Late Holocene environmental history of Kulunda (Southwestern Siberia): vegetation, climate, humans

Science.gov (United States)

Rudaya, N.; Nazarova, L.; Papin, D.; Nourgaliev, D.

2012-04-01

Environmental reconstruction of Mid-Late Holocene vegetation and climate was inferred from pollen records of Lake Big Yarovoe (Kulunda steppe, Southwestern Siberia). Reconstruction suggests generally prevalence of steppe during last 4.45 ka. Relatively warm and dry climate, open semi-desert and dry steppes with patchy birch forest spread between 4.45 and 3.80 ka BP. The largest development of conifers forest started in Kulunda after 3.80 ka BP. Constant presence of dark-coniferous trees Abies and especially Picea between 3.80 and 2.7 ka BP indicates the most humid period in the region during studied time. Onset of the Late Holocene is characterised by dominance of steppe with birch and pine forests in lowlands and river valleys. After AD 1860, open steppe and semi-desert vegetation with fragmentary birch forest have been dominated parallel to sharp reduction of conifers in Kulunda. These results are in agreement with general scheme of Holocene environmental history of surrounding areas including Baraba forest-steppe, Kazakh Upland and Altai Mountains. Territory of Kulunda consists many archaeological sites of Bronze, Iron and Middle Ages. Second half of Bronze Age (4.45-3.80 ka BP) was represented by local human cultures or migrants from the North Kazakhstan. The main archaeological culture of Kulunda alike in the whole Ob`-Irtysh interfluve in this period was Elunino culture. The economical activities of Elunino community were connected with animal breeding especially with sheep and goats. The most humid period (~1795-710 BC; 3.8-2.7 ka BP) in Kulunda corresponded to the end of early Bronze Age and to the onset of the Iron Age. In 18 century BC Andronovo culture, associated with the Indo-Iranians and migrants from Central Kazakhstan, spread in the region. Cattle breeding economy was distinctive features of Andronovo people, however, increase of sheep, goats and horses with transition to nomadic life style was characteristic of the late Bronze Age. This trend is in

Birds of a Great Basin Sagebrush Habitat in East-Central Nevada

OpenAIRE

United States Department of Agriculture, Forest Service

1992-01-01

Breeding bird populations ranged from 3.35 to 3.48 individuals/ha over a 3-year study conducted from 1981 to 1983. Brewer's sparrows, sage sparrows, sage thrashers, and black-throated sparrows were numerically dominant. Horned larks and western meadowlarks were less common. Results are compared with bird populations in Great Basin sagebrush habitats elsewhere in the United States.

Grazing effects on ecosystem CO2 fluxes differ among temperate steppe types in Eurasia.

Science.gov (United States)

Hou, Longyu; Liu, Yan; Du, Jiancai; Wang, Mingya; Wang, Hui; Mao, Peisheng

2016-07-01

Grassland ecosystems play a critical role in regulating CO2 fluxes into and out of the Earth's surface. Whereas previous studies have often addressed single fluxes of CO2 separately, few have addressed the relation among and controls of multiple CO2 sub-fluxes simultaneously. In this study, we examined the relation among and controls of individual CO2 fluxes (i.e., GEP, NEP, SR, ER, CR) in three contrasting temperate steppes of north China, as affected by livestock grazing. Our findings show that climatic controls of the seasonal patterns in CO2 fluxes were both individual flux- and steppe type-specific, with significant grazing impacts observed for canopy respiration only. In contrast, climatic controls of the annual patterns were only individual flux-specific, with minor grazing impacts on the individual fluxes. Grazing significantly reduced the mean annual soil respiration rate in the typical and desert steppes, but significantly enhanced both soil and canopy respiration in the meadow steppe. Our study suggests that a reassessment of the role of livestock grazing in regulating GHG exchanges is imperative in future studies.

A network of the steppe and forest steppe along the Prut and Lower Danube rivers during the 6th millennium BC

Directory of Open Access Journals (Sweden)

Agathe Reingruber

2016-12-01

Full Text Available The transition from a (predominantly mobile way of life relying on hunting, fishing and gathering to a (predominantly sedentary life-style based on farming and animal husbandry is considered in the western Pontic archaeological tradition almost exclusively from a southern, AegeanAnatolian perspective. Contacts between the steppe and forest steppe of the north-eastern Balkans and the north-western Pontic were seen as linear and unidirectional; ‘cultures’ were defined almost exclusively on the basis of pottery styles. Not only such traditional viewpoints, but also the political conditions of the 20th century further biased prehistoric research. However, the outer Carpathian region should not be treated as a periphery of the inner Carpathian Cris culture, but as a region of multidirectional exchange networks. Moreover, certain traditions are obviously rooted in the Mesolithic of that area.

Modeling of the evolution of steppe chernozems and development of the method of pedogenetic chronology

DEFF Research Database (Denmark)

Lisetskii, F.N.; Stolba, Vladimir; Goleusov, P.V.

2016-01-01

Geoarchaeological methods were used to study chronosequences of surface soils in the steppe zone and to trace soil evolution during the Late Holocene in northwestern Crimea. It was found that the morphological and functional “maturity” of the humus horizons in steppe chernozems of the Late Holocene...

Big sagebrush in pinyon-juniper woodlands: Using forest inventory and analysis data as a management tool for quantifying and monitoring mule deer habitat

Science.gov (United States)

Chris Witt; Paul L. Patterson

2011-01-01

We used Interior West Forest Inventory and Analysis (IW-FIA) data to identify conditions where pinyon-juniper woodlands provide security cover, thermal cover, and suitable amounts of big sagebrush (Artemisia tridentata spp.) forage to mule deer in Utah. Roughly one quarter of Utah's pinyon-juniper woodlands had a big sagebrush component in their understory....

Controls of vegetation structure and net primary production in restored grasslands

Science.gov (United States)

Munson, Seth M.; Lauenroth, William K.

2014-01-01

1. Vegetation structure and net primary production (NPP) are fundamental properties of ecosystems. Understanding how restoration practices following disturbance interact with environmental factors to control these properties can provide insight on how ecosystems recover and guide management efforts. 2. We assessed the relative contribution of environmental and restoration factors in controlling vegetation structure, above- and below-ground investment in production across a chronosequence of semiarid Conservation Reserve Program (CRP) fields recovering from dryland wheat cropping relative to undisturbed grassland. Importantly, we determined the role of plant diversity and how seeding either native or introduced perennial grasses influenced the recovery of vegetation properties. 3. Plant basal cover increased with field age and was highest in CRP fields seeded with native perennial grasses. In contrast, fields seeded with introduced perennial grasses had tall-growing plants with relatively low basal cover. These vegetation structural characteristics interacted with precipitation, but not soil characteristics, to influence above-ground NPP (ANPP). Fields enrolled in the CRP program for >7 years supported twice as much ANPP as undisturbed shortgrass steppe in the first wet year of the study, but all CRP fields converged on a common low amount of ANPP in the following dry year and invested less than half as much as the shortgrass steppe in below-ground biomass. 4. ANPP in CRP fields seeded with native perennial grasses for more than 7 years was positively related to species richness, whereas ANPP in CRP fields seeded with introduced perennial grasses were controlled more by dominant species. 5. Synthesis and applications. Seeding with introduced, instead of native, perennial grasses had a strong direct influence on vegetation structure, including species richness, which indirectly affected NPP through time. However, the effects of restoring either native or introduced

Mineral weathering experiments to explore the effects of vegetation shifts in high mountain region (Wind River Range, Wyoming, USA)

Science.gov (United States)

Mavris, Christian; Furrer, Gerhard; Dahms, Dennis; Anderson, Suzanne P.; Blum, Alex; Goetze, Jens; Wells, Aaron; Egli, Markus

2015-04-01

Climate change influences the evolution of soil and landscape. With changing climate, both flora and fauna must adapt to new conditions. It is unknown in many respects to what extent soils will react to warming and vegetation change. The aim of this study was to identify possible consequences for soils in a dry-alpine region with respect to weathering of primary minerals and leaching of elements under expected warming climate conditions due to shifts in vegetation. To achieve this, a field empirical approach was used in combination with laboratory weathering experiments simulating several scenarios. Study sites located in Sinks Canyon and in Stough Basin of the Wind River Range, Wyoming, USA, encompass ecotones that consist of tundra, forest, or sagebrush (from moist to dry, with increasing temperature, respectively). All soils are developed on granitoid moraines. The mineralogy of the soils along the altitudinal sequence was analysed using cathodoluminescence and X-ray diffraction, and revealed clear mineral transformations: biotite and plagioclase were both weathered to smectite while plagioclase also weathered to kaolinite. Cooler, wetter, altitude-dependent conditions seemed to promote weathering of these primary minerals. To test the impact of soil solutions from different ecotones on mineral weathering, aqueous extracts from topsoils (A horizons) were reacted with subsoils (B horizons) in batch experiments. Aqueous extracts of topsoil samples were generated for all three ecotones, and these solutions were characterized. For the batch experiments, the topsoil extracts were reacted for 1800 hours with the subsoil samples of the same ecotone, or with the subsoil samples from higher altitude ecotones. Solutions collected periodically during the experiments were measured using ICP-OES and ion chromatography. Dissolved Ca, Mg and K were mainly controlled by the chemical weathering of oligoclase, K-feldspar and biotite. With increasing altitude (and consequently

Mapping Fearscapes of a Mammalian Herbivore using Terrestrial LiDAR and UAV Imagery

Science.gov (United States)

Olsoy, P.; Nobler, J. D.; Forbey, J.; Rachlow, J. L.; Burgess, M. A.; Glenn, N. F.; Shipley, L. A.

2013-12-01

Concealment allows prey animals to remain hidden from a predator and can influence both real and perceived risks of predation. The heterogeneous nature of vegetative structure can create a variable landscape of concealment - a 'fearscape' - that may influence habitat quality and use by prey. Traditional measurements of concealment rely on a limited number of distances, heights, and vantage points, resulting in small snapshots of concealment available to a prey animal. Our objective was to demonstrate the benefits of emerging remote sensing techniques to map fearscapes for pygmy rabbits (Brachylagus idahoensis) in sagebrush steppe habitat across a continuous range of scales. Specifically, we used vegetation height rasters derived from terrestrial laser scanning (TLS) to create viewsheds from multiple vantage points, representing predator visibility. The sum of all the viewsheds modeled horizontal concealment of prey at both the shrub and patch scales. We also used a small, unmanned aerial vehicle (UAV) to determine vertical concealment at a habitat scale. Terrestrial laser scanning provided similar estimates of horizontal concealment at the shrub scale when compared to photographic methods (R2 = 0.85). Both TLS and UAV provide the potential to quantify concealment of prey from multiple distances, heights, or vantage points, allowing the creation of a manipulable fearscape map that can be correlated with habitat use by prey animals. The predictive power of such a map also could identify shrubs or patches for fine scale nutritional and concealment analysis for future investigation and conservation efforts. Fearscape map at the mound-scale. Viewsheds were calculated from 100 equally spaced observer points located 4 m from the closest on-mound sagebrush of interest. Red areas offer low concealment, while green areas provide high concealment.

Surface Runoff and Snowmelt Infiltration into the Soil on Plowlands in the Forest-Steppe and Steppe Zones of the East European Plain

Science.gov (United States)

Barabanov, A. T.; Dolgov, S. V.; Koronkevich, N. I.; Panov, V. I.; Petel'ko, A. I.

2018-01-01

Long-term series of observations over the spring water balance elements on fields with hydrologically contrasting agricultural backgrounds―a loose soil after fall moldboard plowing and a plowland compacted by 12-16% compared to the former soil (perennial grasses, winter crops, stubble)―have been analyzed. The values of surface runoff and water infiltration into the soil in the steppe and forest-steppe zones of European Russia have been calculated for the spring (flooding) period and the entire cold season. The hydrological role of fall plowing has been shown, and water balance elements for the current (1981-2016) and preceding (1957-1980) periods have been compared. A significant decrease in runoff and an increase of water reserve in the soil have been revealed on all plowland types. Consequences of changes in the spring water balance on plowland have been analyzed.

Short-term regeneration dynamics of Wyoming big sagebrush at two sites in northern Utah

Science.gov (United States)

The herbicide tebuthiuron has been used historically to control cover of Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis - complete taxonomic designation), a widespread shrub across the western United States, with the intent of increasing herbaceous plant cover. Although the tebuthiur...

Attempting to restore mountain big sagebrush (Artemisia tridentata ssp. vaseyana) four years after fire

Science.gov (United States)

Restoration of shrubs is increasingly needed throughout the world because of altered fire regimes, anthropogenic disturbance, and over-utilization. The native shrub mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana (Rydb.) Beetle) is a restoration priority in western North America be...

Variation in sagebrush communities historically seeded with crested wheatgrass in the eastern great basin

Science.gov (United States)

Although crested wheatgrass (CWG; Agropyron cristatum [L.] Gaertn.) has been one of the most commonly seeded exotic species in the western United States, long-term successional trajectories of seeded sites are poorly characterized, especially for big sagebrush (Artemisia tridentana Nutt.) ecosystems...

Effects of Prescribed Burning on Grazed Shortgrass Steppe

Science.gov (United States)

Over the past century, fire has been widely suppressed in the western Great Plains, in part due to potential negative effects on forage production for livestock. Interest in the use of prescribed fire in shortgrass steppe has increased recently due to applications for wildlife management, control of...

Possibility of Morphometrical Determining of Sex of Steppe Eagle Nestlings from Western and Eastern Populations?

Directory of Open Access Journals (Sweden)

Igor V. Karyakin

2018-03-01

Full Text Available Sexual dimorphism among nestlings of the Steppe Eagle (Aquila nipalensis is poorly manifested. Thus, determining of sex by morphometric methods encountered many difficulties and could be completed only by the most experienced ornithologists who knows the species very well. This article presents a morphometric method for determining sex of nestlings of the Steppe Eagles from different breeding populations that belongs to different size classes. The method is based on classification formula obtained via linear discriminant analysis conducted for the data set of measurements of Steppe Eagle’s nestlings from Central Kazakhstan and Altai Republic in 2017. To control the sex determination of nestlings a molecular-genetics method was used.

Detection of damaged areas caused by the oil extraction in a steppe region using winter landsat imagery

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Mjachina, Ksenya; Hu, Zhiyong; Chibilyev, Alexander

2018-01-01

Oil production in a steppe region disturbs the landscape and damages the steppe ecosystem. The objective of this research was to detect areas damaged by oil production in an oil field within the Russian Volga-Ural steppe region using winter Landsat imagery. We developed a practicable and effective approach using winter snow season multispectral Landsat satellite imagery. To this end, we applied seven algorithms of spectral or texture-based transformation: K-means, maximum likelihood estimation, topsoil grain size index, soil brightness, normalized differential snow index, tasselled cap, and co-occurrence measures. The co-occurrence texture measure variance shows the optimal result of identifying damaged areas. The unique feature of our method is that it can differentiate damaged areas from the bare soil of cropland within a cold steppe region where the area damaged by oil production is mixed with bare (fallow) croplands that have a polygonal shape similar to well pads. Such similarities can lead to confusion in object-based classification. Using the co-occurrence measures, we found that from 1988 to 2015, damaged area is nearly three times as big in the peak period of the oil field development (2001 and 2009) as in 1988. Landscape fragmentation also peaked in 2001 and 2009. Our approach for this project is useful and cost effective regular monitoring of damages from oil production for both the Volga-Ural steppe region and other cold steppe regions.

Seasonal soil CO2 flux under big sagebrush (Artemisia tridentata Nutt.)

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Michael C. Amacher; Cheryl L. Mackowiak

2011-01-01

Soil respiration is a major contributor to atmospheric CO2, but accurate landscape-scale estimates of soil CO2 flux for many ecosystems including shrublands have yet to be established. We began a project to measure, with high spatial and temporal resolution, soil CO2 flux in a stand (11 x 25 m area) of big sagebrush (Artemisia tridentata Nutt.) at the Logan, Utah,...

Ancestry and demography and descendants of Iron Age nomads of the Eurasian Steppe

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Unterländer, Martina; Palstra, Friso; Lazaridis, Iosif; Pilipenko, Aleksandr; Hofmanová, Zuzana; Groß, Melanie; Sell, Christian; Blöcher, Jens; Kirsanow, Karola; Rohland, Nadin; Rieger, Benjamin; Kaiser, Elke; Schier, Wolfram; Pozdniakov, Dimitri; Khokhlov, Aleksandr; Georges, Myriam; Wilde, Sandra; Powell, Adam; Heyer, Evelyne; Currat, Mathias; Reich, David; Samashev, Zainolla; Parzinger, Hermann; Molodin, Vyacheslav I.; Burger, Joachim

2017-03-01

During the 1st millennium before the Common Era (BCE), nomadic tribes associated with the Iron Age Scythian culture spread over the Eurasian Steppe, covering a territory of more than 3,500 km in breadth. To understand the demographic processes behind the spread of the Scythian culture, we analysed genomic data from eight individuals and a mitochondrial dataset of 96 individuals originating in eastern and western parts of the Eurasian Steppe. Genomic inference reveals that Scythians in the east and the west of the steppe zone can best be described as a mixture of Yamnaya-related ancestry and an East Asian component. Demographic modelling suggests independent origins for eastern and western groups with ongoing gene-flow between them, plausibly explaining the striking uniformity of their material culture. We also find evidence that significant gene-flow from east to west Eurasia must have occurred early during the Iron Age.

Remote sensing data to classify functional groups of vegetation and their distribution and abundance in a semiarid mountain watershed, Idaho, USA

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Loughridge, R. E.; Benner, S. G.; McNamara, J. P.; Flores, A. N.

2012-12-01

In water-limited montane ecosystems, topography is a significant driver of energy balance and soil moisture and therefore governs the distribution and abundance of terrestrial vegetation. Few studies have made a concerted effort to quantify spatial patterns in vegetation along physiographic gradients that control microclimate such as slope, elevation, and aspect. Furthermore, spectral mixing of different vegetation species within individual visible and near-infrared remote sensing pixels makes it difficult to constrain the temporal growth and senescence of individual plant functional types. We report on a study that seeks to understand the interacting roles of topography, soil moisture, and solar radiation on the distribution of different plant functional types within the Dry Creek Experimental Watershed (DCEW). Boise State University maintains the 27 km2 watershed which is located in the Boise Front Mountains of southwest Idaho. It is qualitatively observed in DCEW that low elevations are dominated by sage-steppe ecosystems and high elevations transition to conifer forests. It is also observed that aspect has a major control in which sage-steppe is evident at high elevations on south facing slopes conversely from north facing slopes. To quantify these trends we measured percent ground cover of functional groups (i.e. forbs, grass, shrubs, etc.) at 77 sites within DCEW spanning a large gradient in the controlling biophysiographic variables. In addition, vegetation water content (VWC) and spectral reflectance from the 325 to 1075 nm wavelengths was collected for specific vegetation types at eight permanent soil moisture monitoring sites contained in DCEW throughout the 2012 green-up/senescence transition. To develop a watershed-wide classification we built a supervised multilayer perceptron (MLP) backpropagating artificial neural network (ANN) using temporal Landsat 5 images to classify 4 major groups: sage-steppe, Douglas fir, ponderosa pine, and deciduous trees

Tapping soil survey information for rapid assessment of sagebrush ecosystem resilience and resistance

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Jeremy D. Maestas; Steven B. Campbell; Jeanne C. Chambers; Mike Pellant; Richard F. Miller

2016-01-01

A new ecologically-based approach to risk abatement has emerged that can aid land managers in grappling with escalating impacts of large-scale wildfire and invasive annual grasses in sagebrush ecosystems, particularly in the Great Basin. Specifically, ecosystem resilience and resistance (R&R) concepts have been more fully operationalized from regional...

Steppe bison paleobiology through the scope of stable isotopes and zooarchaeology

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Julien, Marie-Anne; Dorothée, Drucker; Hervé, Bocherens; Ariane, Burke; Marylène, Patou-Mathis; Alexandra, Krotova

2010-05-01

Bison are one of the most abundant and widely distributed species of large mammal during the Late Pleistocene. In the southern steppes of Eastern Europe, steppe bison (Bison priscus) is ubiquitous in zooarchaeological assemblages, particularly during the Upper Palaeolithic when a model of economic "specialization" is proposed. Specialization, in this context, implies the deliberate selection of a preferred species, which becomes the key food resource. The applicability of a specialised hunting model for the Upper Palaeolithic of Europe has recently been challenged, however (Grayson & Delpech 2002). In this research, therefore we re-examine bison acquisition strategies during the Upper Palaeolithic in the Ukrainian steppes in the light of biogeochemical and zooarchaeological data. The acquisition strategies used to procure a prey species are directly related to its social and spatial behaviour. A synthesis of ethological information for contemporary bison (Julien 2009) demonstrates the behavioural diversity of this taxa, linked mainly to local environmental variability, climatic conditions and population density. It is therefore necessary to propose a paleoethological model for the steppe bison before attempting to identify the acquisition strategies used by prehistoric hunters. In this research, we reconstruct the behaviour of the steppe bison using a combination of zooarchaeological tools, stable isotope analysis (intra-tooth isotope variation of carbon, oxygen and strontium ratios) and traditional paleobiological approaches. The advantages of using a combined approach are demonstrated through the examination of a case study: the site of Amvrosievka (Ukraine). Amvrosievka is a complex of Epigravettian sites composed of a camp and kill site, where more than 500 bison are represented (Krotova & Belan 1993). Twenty-five permanent lower teeth (M3) representing twenty-five individual bison were selected from the kill and camp site for isotopic analysis. Intra- and

Sediment-palaeosol successions in Calabria and Sardinia suggest spatially differentiated palaeo-vegetation patterns in southern Italy during the Last Glacial period

Science.gov (United States)

Sauer, Daniela; Zucca, Claudio; Al-Sharif, Riyad; Zwanzig, Lisa; Madrau, Salvatore; Andreucci, Stefano; Pascucci, Vincenzo; Kadereit, Annette; Scarciglia, Fabio; Brückner, Helmut

2016-04-01

Several lakes on the southern Italian peninsula provide valuable palaeoenvironmental archives of the Last Glacial period. These archives include, e.g., the long high-resolution record from varved lake sediments of Lago Grande di Monticchio, the bigger one of two maar lakes situated on top of Mt. Vulture. Its pollen record indicates (1) temperate deciduous forest during MIS5.2-MIS5.1 (St. Germain 2); (2) frequent vegetation fluctuations, then Artemisia steppe during MIS5.1-MIS4; (3) alternations between open steppe (stadials) and wooded steppe (interstadials) during MIS3; and (4) open steppe during MIS2 (Last Glacial Maximum). However, only few palaeosol records of this period have been reported from southern Italy in the literature so far. Such records would allow for gaining insight also into spatial patterns of the vegetation cover during this period that should have formed, e.g., according to relief, elevation, and continentality gradient (related to the much lower coastline during the last glacial period). So far, we have studied three sediment-palaeosol successions in southern Italy, two in the Calabria region, and one in north-western Sardinia. All of them have developed in alluvial fan deposits resting on littoral sediments of the Last Interglacial period (MIS 5). The southernmost succession studied is located near Lazzaro (south of Reggio di Calabria). It is exposed in an alluvial fan overlying the MIS5.5 terrace. Due to strong tectonic uplift (1.3 m ka-1) the alluvial fan has been dissected by the same creek which previously had built it up. Therefore, its internal structure is exposed, exhibiting a detailed sediment-palaeosol sequence. The palaeosols are mainly characterized by accumulation of soil organic matter (SOM), bioturbation and secondary carbonates. They represent Chernozem- and Phaeozem-like soils that most likely formed under steppe to forest steppe. SOM of the two uppermost Lazzaro palaeosols was 14C-dated to 26.8-28.8 ka cal BP and 28

On the issue of taxonomical status of steppe viper (Vipera renardi in Right-bank Ukraine

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A. L. Baybuz

2011-07-01

Full Text Available Data on morphologic variability of the steppe viper in the Kirovograd region (Right-bank Ukraine are given firstly. Tentative estimation of the similaritylevel of the local population and the populations from the Left-bank Ukraine and the Crimea was carried out using methods of the multivariate statistics. Morphological data in line with the results of mitochondrial DNA analysis show that the population in the Kirovograd region belongs to widespread Eurasian species Vipera renardiand morphologically most close to the original populations of the lowland Crimea, Sivash and Forest-Steppe of the Left-bank Ukraine. This could indicate the complicated history of the Right-bank Ukraine colonization by the steppe viper and possible influence of environmental conditions on the vipers’ morphology

Meta-STEPP: subpopulation treatment effect pattern plot for individual patient data meta-analysis.

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Wang, Xin Victoria; Cole, Bernard; Bonetti, Marco; Gelber, Richard D

2016-09-20

We have developed a method, called Meta-STEPP (subpopulation treatment effect pattern plot for meta-analysis), to explore treatment effect heterogeneity across covariate values in the meta-analysis setting for time-to-event data when the covariate of interest is continuous. Meta-STEPP forms overlapping subpopulations from individual patient data containing similar numbers of events with increasing covariate values, estimates subpopulation treatment effects using standard fixed-effects meta-analysis methodology, displays the estimated subpopulation treatment effect as a function of the covariate values, and provides a statistical test to detect possibly complex treatment-covariate interactions. Simulation studies show that this test has adequate type-I error rate recovery as well as power when reasonable window sizes are chosen. When applied to eight breast cancer trials, Meta-STEPP suggests that chemotherapy is less effective for tumors with high estrogen receptor expression compared with those with low expression. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Investing in rangeland restoration in the Arid West, USA: countering the effects of an invasive weed on the long-term fire cycle.

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Epanchin-Niell, Rebecca; Englin, Jeffrey; Nalle, Darek

2009-01-01

In large areas of the arid western United States, much of which are federally managed, fire frequencies and associated management costs are escalating as flammable, invasive cheatgrass (Bromus tectorum) increases its stronghold. Cheatgrass invasion and the subsequent increase in fire frequency result in the loss of native vegetation, less predictable forage availability for livestock and wildlife, and increased costs and risk associated with firefighting. Revegetation following fire on land that is partially invaded by cheatgrass can reduce both the dominance of cheatgrass and its associated high fire rate. Thus restoration can be viewed as an investment in fire-prevention and, if native seed is used, an investment in maintaining native vegetation on the landscape. Here we develop and employ a Markov model of vegetation dynamics for the sagebrush steppe ecosystem to predict vegetation change and management costs under different intensities and types of post-fire revegetation. We use the results to estimate the minimum total cost curves for maintaining native vegetation on the landscape and for preventing cheatgrass dominance. Our results show that across a variety of model parameter possibilities, increased investment in post-fire revegetation reduces long-term fire management costs by more than enough to offset the costs of revegetation. These results support that a policy of intensive post-fire revegetation will reduce long-term management costs for this ecosystem, in addition to providing environmental benefits. This information may help justify costs associated with revegetation and raise the priority of restoration in federal land budgets.

Magnetic Soils Profiles in the Volga-Kama Forest-Steppe Region

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L.A. Fattakhova

2016-09-01

Full Text Available The magnetic properties of virgin forest-steppe soils developed on the originally vertically uniform unconsolidated parent material have been investigated. The profile samples of virgin dark-grey forest light-clayey soil derived from a siltstone of the Kazan layer of the Upper Permian and virgin leached medium-thick fertile light-clayey chernozem derived from a Quaternary heavy deluvial loam have been considered. Both soils are characterized by the accumulative type of magnetic susceptibility and F-factor values distribution patterns with depth. In the humus part of the soil profile, magnetics are present pre-dominantly in the < 2.5 µm fraction. The coercivity spectra allowed to determine the contribution of dia-/paramagnetic and ferromagnetic components to magnetic susceptibility. It has been found that magnetic susceptibility enhancement in the organogenic horizons of virgin forest-steppe soils occurs due to the contribution of ferromagnetic components. The results indicate a strong positive linear correlation between the magnetic susceptibility and oxalate-extractable Fe, as well as between the magnetic susceptibility and Schwertmann’s criterion values. Using the method of thermomagnetic analysis of the < 2.5 µm fraction, it has been found that the magnetic susceptibility enhancement in the profiles of forest-steppe soils took place due to the formation of maghemite-magnetite associations. The predominantly ferromagnetic fraction consists of small single-domain grains.

Dating simple flakes: Early Bronze Age flake production technology on the Middle Euphrates Steppe, Syria

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Yoshihiro Nishiaki

2014-03-01

Full Text Available Aceramic flint scatters, comprising very crude cores or flakes and no formalised tools, are frequently found on the Middle Euphrates steppe of northern Syria. Previous studies suggest that many of them are residues of short-term activities by the nomads or shepherds of the Early Bronze Age. In order to verify this interpretation, a more precise chronological framework needs to be established for the Early Bronze Age lithic industry. This paper analyses stratified flake assemblages of the Early Bronze Age at Tell Ghanem al-Ali, a securely radiocarbon-dated settlement on the Middle Euphrates, and examines which occupation level yields assemblages most similar to those of the steppe. Results demonstrate that the lithic industry of this period underwent significant diachronic changes in terms of core reduction technology. Based on the chronological framework developed at Tell Ghanem al-Ali, the steppe assemblages in question can be assigned to different phases of the Early Bronze Age. This finding will help identify processes at the beginning of the extensive exploitation of the steppe, which is regarded as one of the most important socioeconomic changes that occurred among Early Bronze Age communities of the Middle Euphrates.

Using resistance and resilience concepts to reduce impacts of annual grasses and altered fire regimes on the sagebrush ecosystem and sage-grouse- A strategic multi-scale approach

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Chambers, Jeanne C.; Pyke, David A.; Maestas, Jeremy D.; Boyd, Chad S.; Campbell, Steve; Espinosa, Shawn; Havlina, Doug; Mayer, Kenneth F.; Wuenschel, Amarina

2014-01-01

This Report provides a strategic approach for conservation of sagebrush ecosystems and Greater Sage- Grouse (sage-grouse) that focuses specifically on habitat threats caused by invasive annual grasses and altered fire regimes. It uses information on factors that influence (1) sagebrush ecosystem resilience to disturbance and resistance to invasive annual grasses and (2) distribution, relative abundance, and persistence of sage-grouse populations to develop management strategies at both landscape and site scales. A sage-grouse habitat matrix links relative resilience and resistance of sagebrush ecosystems with sage-grouse habitat requirements for landscape cover of sagebrush to help decision makers assess risks and determine appropriate management strategies at landscape scales. Focal areas for management are assessed by overlaying matrix components with sage-grouse Priority Areas for Conservation (PACs), breeding bird densities, and specific habitat threats. Decision tools are discussed for determining the suitability of focal areas for treatment and the most appropriate management treatments.

Phenotypic variability of plant leaves of Acer genus, introduced into steppe zone of Ukraine

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I. O. Zaitseva

2014-10-01

Full Text Available This paper deals with studying of the patterns of ecological adaptation of wood species of Acer L. genus during their introduction into steppe zone of Ukraine. Hydrothermal conditions of the growing season in steppe zone of Ukraine are particularly unfavorable for tree and shrubbery plantings, comprising both native and introduced species. In the course of plants’ introduction, adaptive changes occur; such changes represent the spectrum of phenotypic implementation of the definite genotype under the influence of new environmental conditions. Stress environment of the region of introduction leads to occurrence of a great variety of phenotypic forms, as the different variants of genotype implementation. Studying of phenotypic variability gives an opportunity to determine the capacity to adaptation of introduced species and ways of adaptive reactions in new conditions of living. Therefore, objective of the work consists in studying of the processes of differentiation of morphological characters in species of Acer genus introduced in the regions of steppe zone with varying intensity of hydrothermal factors. Studies were carried out in the central and south-eastern steppe regions, as well as in the south of steppe zone in the coastal and continental areas. Subjects of research were 9 species of maples, differing by their botanic and geographic origin and by the degree of drought resistance in the steppe zone of Ukraine. Patterns of variability of morphostructural characters of leaves were determined by the indicator of specific weight of leaves which was calculated as a ratio of weight of dry laminas to their area (mg/cm2. Following the results of study, it was found that adaptation of maples to xerothermic factors of the environment is connected with changing of the ratio of groups of character variation and their contribution into total sample. Direct relationship is established between the probability density of expression (phenotypic

[Team Care for Patient Safety, TeamSTEPPS to Improve Nontechnical Skills and Teamwork--Actions to Become an HRO].

Science.gov (United States)

Kaito, Ken

2015-07-01

It is important to develop safer medical systems and follow manuals of medical procedures for patient safety. However, these approaches do not always result in satisfactory results because of many human factors. It is known that defects of nontechnical skills are more important than those of technical skills regarding medical accidents and incidents. So, it is necessary to improve personal nontechnical skills and compensate for each other's defects based on a team approach. For such purposes, we have implemented TeamSTEPPS to enhance performance and patient safety in our hospital. TeamSTEPPS (team strategies and tools to enhance performance and patient safety) is a useful method to improve the nontechnical skills of each member and the team. In TeamSTEPPS, leadership to share mental models among the team, continuous monitoring and awareness for team activities, mutual support for workload and knowledge, and approaches to complete communication are summarized to enhance teamwork and patient safety. Other than improving nontechnical skills and teamwork, TeamSTEPPS is also very important as a High Reliability Organization (HRO). TeamSTEPPS is worth implementing in every hospital to decrease medical errors and improve patient outcomes and satisfaction.

Using resilience and resistance concepts to manage threats to sagebrush ecosystems, Gunnison sage-grouse, and Greater sage-grouse in their eastern range: A strategic multi-scale approach

Science.gov (United States)

Jeanne C. Chambers; Jeffrey L. Beck; Steve Campbell; John Carlson; Thomas J. Christiansen; Karen J. Clause; Jonathan B. Dinkins; Kevin E. Doherty; Kathleen A. Griffin; Douglas W. Havlina; Kenneth F. Henke; Jacob D. Hennig; Laurie L. Kurth; Jeremy D. Maestas; Mary Manning; Kenneth E. Mayer; Brian A. Mealor; Clinton McCarthy; Marco A. Perea; David A. Pyke

2016-01-01

This report provides a strategic approach developed by a Western Association of Fish and Wildlife Agencies interagency working group for conservation of sagebrush ecosystems, Greater sage-grouse, and Gunnison sage-grouse. It uses information on (1) factors that influence sagebrush ecosystem resilience to disturbance and resistance to nonnative invasive annual grasses...

Gold and other metals in big sagebrush (Artemisia tridentata Nutt.) as an exploration tool, Gold Run District, Humboldt County, Nevada

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Erdman, J.A.; Cookro, T.M.; O'Leary, R. M.; Harms, T.F.

1988-01-01

Big sagebrush - a cold-desert species that dominates the terrain over large parts of western United States - was sampled along several traverses that crossed thermally metamorphosed limestone, phyllitic shale, and schist of the Middle and Upper Cambrian Preble Formation that host skarn-, disseminated gold and silver-, and hot springs gold-type mineral occurrences. Patterns of detectable levels of gold (8 to 28 ppb or ng g-1) in ash of new growth were consistent with areas affected by known or suspected gold mineralization. Soils collected along one of the traverses where a selenium-indicator plant was common contained no gold above background levels of 2ppb, but were consistently high in As, Sb, and Zn, and several samples were unusually high in Se (maximum 11 ppm or ??g g-1). Sagebrush along this traverse contained Li at levels above norms for this species. We also found a puzzling geochemical anomaly at a site basinward from active hot springs along a range-front fault scarp. Sagebrush at this site contained a trace of gold and an unusually high concentration of Cd (13 ppm) and the soil had anomalous concentrations of Cd and Bi (3.2 and 6 ppm, respectively). The source of this anomaly could be either metal-rich waters from an irrigation ditch or leakage along a buried fault. Despite the limited nature of the study, we conclude that gold in sagebrush could be a cost-effective guide to drilling locations in areas where the geology seems favorable for disseminated and vein precious metals. ?? 1988.

Interspecific nest parasitism by chukar on greater sage-grouse

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Fearon, Michelle L.; Coates, Peter S.

2014-01-01

Nest parasitism occurs when a female bird lays eggs in the nest of another and the host incubates the eggs and may provide some form of parental care for the offspring (Lyon and Eadie 1991). Precocial birds (e.g., Galliformes and Anseriformes) are typically facultative nest parasites of both their own and other species (Lyon and Eadie 1991). This behavior increases a female’s reproductive success when she parasitizes other nests while simultaneously raising her own offspring. Both interspecific and conspecific nest parasitism have been well documented in several families of the order Galliformes, particularly the Phasianidae (Lyon and Eadie 1991, Geffen and Yom-Tov 2001, Krakauer and Kimball 2009). The Chukar (Alectoris chukar) has been widely introduced as a game bird to western North America from Eurasia and is now well established within the Great Basin from northeastern California east to Utah and north to Idaho and Oregon (Christensen 1996). Over much of this range the Chukar occurs with other phasianids, including the native Greater Sage-Grouse (Centrocercus urophasianus), within sagebrush (Artemisia spp.) steppe (Christensen 1996, Schroeder et al. 1999, Connelly et al. 2000). Chukar typically exploit a broader range of habitats than do sage-grouse, but both species use the same species of sagebrush and other shrubs for nesting cover (Christensen 1996, Schroeder et al. 1999). Chukar are known to parasitize nests of other individuals of their own species (Geffen and Yom-Tov 2001), but we are unaware of reported evidence that Chukar may parasitize nests of sage-grouse. Here we describe a case of a Chukar parasitizing a sage-grouse nest in the sagebrush steppe of western Nevada.

An analysis on vegetation pattern of ecotone in North China

Energy Technology Data Exchange (ETDEWEB)

Jia, J.C.; Zhang, H.Y. [North China Electric Power Univ., Beijing (China). Energy and Environmental Research Center

2008-07-01

Vegetation pattern is influenced by several natural factors, including climatic elements, elevation factors and soil conditions. Since soil formation and soil types are influenced by water-temperature conditions, much can be learned about vegetation distribution patterns by studying the relationship between water-temperature conditions and vegetation distribution. This paper presented the results of a study whose purpose was to provide scientific evidence for exploiting natural resources, planting trees, and restoring grassland from cropland. A warmth index (WI ) and humidity index (HI) were used to examine the relation between the distribution of vegetation and the water-temperature condition in North China's ecotone, the transition area between two adjacent but different plant communities, including steppe, bush and forest ecosystems. A vegetation map of the study site was digitized and then converted into a vegetation grid map from which 17 different vegetation types were chosen as the study object. A monthly mean temperature grid map and precipitation grid map of the study site were made based on the method of spatial interpolation, by using 119 meteorological data for 50 years during the period from 1951 to 2000. The thermal distribution curves and humidity distribution curves of 17 vegetation types in North China, determined the whole range and optimum range of WI and HI of 17 vegetation types. The relative proportion of each vegetation type distributed in the optimum range of WI and HI were calculated. The vegetation pattern was analyzed according to the WI and HI standard, and was described by species and their relative amount. 10 refs., 5 tabs., 3 figs.

Science framework for conservation and restoration of the sagebrush biome: Linking the Department of the Interior’s Integrated Rangeland Fire Management Strategy to long-term strategic conservation actions, Part 1. Science basis and applications

Science.gov (United States)

Chambers, Jeanne C.; Beck, Jeffrey L.; Bradford, John B.; Bybee, Jared; Campbell, Steve; Carlson, John; Christiansen, Thomas J; Clause, Karen J.; Collins, Gail; Crist, Michele R.; Dinkins, Jonathan B.; Doherty, Kevin E.; Edwards, Fred; Espinosa, Shawn; Griffin, Kathleen A.; Griffin, Paul; Haas, Jessica R.; Hanser, Steven E.; Havlina, Douglas W.; Henke, Kenneth F.; Hennig, Jacob D.; Joyce, Linda A; Kilkenny, Francis F.; Kulpa, Sarah M; Kurth, Laurie L; Maestas, Jeremy D; Manning, Mary E.; Mayer, Kenneth E.; Mealor, Brian A.; McCarthy, Clinton; Pellant, Mike; Perea, Marco A.; Prentice, Karen L.; Pyke, David A.; Wiechman , Lief A.; Wuenschel, Amarina

2017-01-01

The Science Framework is intended to link the Department of the Interior’s Integrated Rangeland Fire Management Strategy with long-term strategic conservation actions in the sagebrush biome. The Science Framework provides a multiscale approach for prioritizing areas for management and determining effective management strategies within the sagebrush biome. The emphasis is on sagebrush (Artemisia spp.) ecosystems and Greater sage-grouse (Centrocercus urophasianus). The approach provided in the Science Framework links sagebrush ecosystem resilience to disturbance and resistance to nonnative, invasive plant species to species habitat information based on the distribution and abundance of focal species. A geospatial process is presented that overlays information on ecosystem resilience and resistance, species habitats, and predominant threats and that can be used at the mid-scale to prioritize areas for management. A resilience and resistance habitat matrix is provided that can help decisionmakers evaluate risks and determine appropriate management strategies. Prioritized areas and management strategies can be refined by managers and stakeholders at the local scale based on higher resolution data and local knowledge. Decision tools are discussed for determining appropriate management actions for areas that are prioritized for management. Geospatial data, maps, and models are provided through the U.S. Geological Survey (USGS) ScienceBase and Bureau of Land Management (BLM) Landscape Approach Data Portal. The Science Framework is intended to be adaptive and will be updated as additional data become available on other values and species at risk. It is anticipated that the Science Framework will be widely used to: (1) inform emerging strategies to conserve sagebrush ecosystems, sagebrush dependent species, and human uses of the sagebrush system, and (2) assist managers in prioritizing and planning on-the-ground restoration and mitigation actions across the sagebrush biome.

Historical landscape elements in preserving steppic species - vegetation responses on micro-topography and human disturbances

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Deák, Balázs; Valkó, Orsolya; Török, Péter; Tóthmérész, Béla

2017-04-01

Land use changes of past centuries resulted in a considerable loss and isolation of grassland habitats worldwide which also led to a serious loss in ecosystem functions. In intensively used agricultural landscapes remnants of natural flora persisted only in small habitat islands embedded in a hostile matrix, which are inadequate for arable farming or construction. In the steppe zone of Eurasia burial mounds, so-called kurgans, have a great potential to preserve the natural flora and habitats and act as local biodiversity hotspots. Their special micro-topography and historical origin makes kurgans characteristic landscape elements of the steppe region. These features also result in a specific soil development and micro-climate, which makes kurgans especially adequate habitats for several steppe specialist plant species. Furthermore, they are proper objects for studying the effects of present and past human disturbances on the vegetation of semi-natural habitats. Exploration of the main factors driving biodiversity in isolated habitat fragments is crucial for understanding the ecological processes shaping their vegetation and for designing effective strategies for their protection. We surveyed the vegetation of 44 isolated kurgans in East-Hungary and studied the effects of habitat area, slope, recent disturbance, past destruction and the level of woody encroachment on the species richness and cover of grassland specialist and weedy species. We used model selection techniques and linear models for testing relevant factors affecting specialist species in grassland fragments. We found that the biodiversity conservation potential of kurgans is supported by their steep slopes, which provide adequate habitat conditions and micro-climate for steppic specialist plant species. By harbouring several grassland specialist species, kurgans have a great potential for preserving the natural species pool of even considerably altered agricultural landscapes, and can mitigate the

Soil carbon fractions and enzyme activities under different vegetation types on the Loess Plateau of China

OpenAIRE

Zhang, Haixin; Zeng, Quanchao; An, Shaoshan; Dong, Yanghong; Darboux, Frédéric

2016-01-01

Vegetation restoration was effective way of protecting soil erosion and water conservation on the Loess Plateau. Carbon fractions and enzyme activities were sensitive parameters for assessment of soil remediation through revegetation. Forest, forest steppe and grassland soils were collected at 0–5 cm and 5–20 cm soil layers in Yanhe watershed, Shaanxi Province. Urease, sucrase, alkaline phosphatase, soil organic carbon (SOC), microbial biomass carbon (MBC), easily ox...

Projected future vegetation changes for the northwest United States and southwest Canada at a fine spatial resolution using a dynamic global vegetation model.

Science.gov (United States)

Shafer, Sarah; Bartlein, Patrick J.; Gray, Elizabeth M.; Pelltier, Richard T.

2015-01-01

Future climate change may significantly alter the distributions of many plant taxa. The effects of climate change may be particularly large in mountainous regions where climate can vary significantly with elevation. Understanding potential future vegetation changes in these regions requires methods that can resolve vegetation responses to climate change at fine spatial resolutions. We used LPJ, a dynamic global vegetation model, to assess potential future vegetation changes for a large topographically complex area of the northwest United States and southwest Canada (38.0–58.0°N latitude by 136.6–103.0°W longitude). LPJ is a process-based vegetation model that mechanistically simulates the effect of changing climate and atmospheric CO2 concentrations on vegetation. It was developed and has been mostly applied at spatial resolutions of 10-minutes or coarser. In this study, we used LPJ at a 30-second (~1-km) spatial resolution to simulate potential vegetation changes for 2070–2099. LPJ was run using downscaled future climate simulations from five coupled atmosphere-ocean general circulation models (CCSM3, CGCM3.1(T47), GISS-ER, MIROC3.2(medres), UKMO-HadCM3) produced using the A2 greenhouse gases emissions scenario. Under projected future climate and atmospheric CO2 concentrations, the simulated vegetation changes result in the contraction of alpine, shrub-steppe, and xeric shrub vegetation across the study area and the expansion of woodland and forest vegetation. Large areas of maritime cool forest and cold forest are simulated to persist under projected future conditions. The fine spatial-scale vegetation simulations resolve patterns of vegetation change that are not visible at coarser resolutions and these fine-scale patterns are particularly important for understanding potential future vegetation changes in topographically complex areas.

HYGROTOPE AND TROPHOTOPE OF THE STEPPE PRIDNIPROVIE BIOGEOCEONOSIS AS DETERMINANTS OF THE EARTHWORMS (LUMBRICIDAE COMMUNITIES β-DIVERSITY

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A. V. Zhukov

2016-08-01

Full Text Available The role of the hygrotope and trophotope of the steppe Pridniprovie biogeoceonosis has been discussed in present article as being determinants of the β-diversity of earthworms (Lumbricidae communities. Material has been colected to the period 1997-2015. 180 sample polygons have been studied which located in various types of biogeoceonosis. Biogeoceonotic characteristic of the sample polygons have been made on the basis of professor A.L. Belgard forest typology of a steppe zone of Ukraine. Earthworm communities of the steppe Pridniprovie have been established to be presented by 16 species. Hygrotopes, trophotopes and bitope ceonosis features have been shown to be able to explain 72.4 % of a communities’ abundance variation and 73.7 of their % α-diversity by means of second order model. Earthworm communities’ abundance reache their maximum values at a combination of conditions of humidity from hygromesophilous to hygrophilous and conditions of edaphotope trophicity from Dc (linden oakwood to Dn (elm-ashen oakwood and alder forests. The maximum diversity of earthworm communities has been stated to be characteristic for a combination of mesohygrophilous conditions and a trophicity mode Dc, that there corresponds to forest type a linden oakwood with aegopodium. The coenomorphic structure of the biogeocoenosis is statistically significant predictors of both abundance and α-diversity of earthworm communities. Earthworm communities of marsh monocoenosis, meadow-steppe amphicoenosis and steppe monocoenosis have been found as being characterised by minimum abundance and diversity. Moderate level abundance and diversity are characteristic for meadow-forest amphicoenosis, forest pseudomonocoenosis with elements of transformation to steppe and forest-steppe amphicoenosis. High levels of these indexes are typical for forest monocoenosis. Given other conditions of humidity and edaphotope trophicity being equal in forest monocoenosis abundance and

A leadership challenge: staff nurse perceptions after an organizational TeamSTEPPS initiative.

Science.gov (United States)

Castner, Jessica; Foltz-Ramos, Kelly; Schwartz, Diane G; Ceravolo, Diane J

2012-10-01

The purpose of this study was to measure RNs' perceptions of teamwork skills and behaviors in their work environment during a multiphase multisite nursing organizational teamwork development initiative. Teamwork is essential for patient safety in healthcare organizations and nursing teams. Organizational development supporting effective teamwork should include a just culture, engaged leadership, and teamwork training. A cross-sectional survey study of bedside RNs was conducted in one 5-hospital healthcare system after a TeamSTEPPS teamwork training initiative. TeamSTEPPS teamwork training related to improved RN perceptions of leadership. Initiatives to align the perspectives and teamwork efforts of leaders and bedside nurses are indicated and should involve charge nurses in the design.

KIRGHIZ STEPPE IN THE TRAVEL NOTES AND ESSAYS OF M. M. PRISHVIN: IMAGOLOGY AND POETICS

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Elena A. Khudenko

2017-06-01

Full Text Available The article investigates the cross-cutting images and themes related to topography of the Kirghiz steppe (now North-Eastern Kazakhstan in the works of M. M. Prishvin. Three early Prishvin’s texts — a Siberian diary “A Journey from Pavlodar to Karkaralinsk”, essays “Adam and Eve” and “A Black Arab” became an empirical base for it. The marginality of Prishvin’s texts in which the itinerant writer crosses the border between Europe and Asia as well as the border of consciousness, dwelling simultaneously in the space of its own and in the others’ space, permitted to reconstruct the landscape consciousness of the Kirghiz and Russian emigrees. The methodological feature of the study of these works along with the study of the poetics of the steppe images, the Kazakh, local legends and nomadic subjects, was a description of their imagological component induced by socio-historical, political and ethnic processes of the early twentieth century, the writer talks about in his books. So, the overall strategy of the narrative, moving from a documentary and essay principle to the poetic saturation by images is formed in his diaries. The essay “Adam and Eve” considers the issue of Russian immigrants, demonstrates the incompatibility between sedentary and nomadic life as two types of national behavior. A twofold image of the steppe — a foodless and saline steppe, and a rich and populated one — sets the parameters of social behavior of the rich and the poor in his essay “A Black Arab”. Basing on its materials the distinctive marks of the steppe as the Paradise are explored. Thus, the Asiatic world is seen by Prishvin through the principle of the landscape consciousness, which allowed reconstructing the features of the national image on the whole.

Science framework for conservation and restoration of the sagebrush biome: Linking the Department of the Interior’s Integrated Rangeland Fire Management Strategy to long-term strategic conservation actions

Science.gov (United States)

J.C. Chambers; J.L. Beck; J.B. Bradford; J. Bybee; S. Campbell; J. Carlson; T.J. Christiansen; K.J. Clause; G. Collins; M.R. Crist; J.B. Dinkins; K.E. Doherty; F. Edwards; S. Espinosa; K.A. Griffin; P. Griffin; J.R. Haas; S.E. Hanser; D.W. Havlina; K.F. Henke; J.D. Hennig; L.A. Joyce; F.M. Kilkenny; S.M. Kulpa; L.L. Kurth; J.D. Maestas; M. Manning; K.E. Mayer; B.A. Mealor; C. McCarthy; M. Pellant; M.A. Perea; K.L. Prentice; D.A. Pyke; L.A. Wiechman; A. Wuenschel

2017-01-01

The Science Framework is intended to link the Department of the Interior’s Integrated Rangeland Fire Management Strategy with long-term strategic conservation actions in the sagebrush biome. The Science Framework provides a multiscale approach for prioritizing areas for management and determining effective management strategies within the sagebrush biome. The emphasis...

Relationships between vegetation and climate change in Transbaikalia, Siberia

Energy Technology Data Exchange (ETDEWEB)

Tchebakova, N.M.; Parfenova, E.I. [V.N. Sukachev Inst. of Forest, Russian Academy of Sciences, Siberian Branch, Akademgorodok, Krasnoyarsk (Russian Federation)

2002-10-01

This paper demonstrated how vegetation of the Lake Baikal basin may respond to climate change at a mountain biome (an orobiome over the entire basin) and a stand in a locality. An orobiome vegetation model was developed along with a higher resolution stand model based on climatic parameters. Regional climates were modeled based on physiology and site climates based on topography. Bioclimatic multiple regression models were then developed to predict regional vegetation and forest stand characteristics distribution over a mountain range in Central Transbaikalia under current and future climate scenarios. Bioclimatic models were combined with climatic layers of different resolutions. Tree species composition and wood volume was predicted based on 2 climate indices - temperature sums (base 5 degrees C) and the dryness index. Results indicate that lowland vegetation will shift 250 m upslope and highland vegetation will shift 450 m upslope. This will significantly reduce the tundra and light-needled taiga, and will expand the forest-steppe. Results also indicate that the total phytomass within the entire basin will not change much. Stand phytomass across the basin will, however, increase. The model used in this study does not include climate-forcing factors such as wind, snow and permafrost. The model is open to new development to include a dynamic components that would inject vitality into the model. 13 refs., 2 tabs., 3 figs.

Sage-Grouse and Wind Energy: Biology, Habits, and Potential Effects from Development

Energy Technology Data Exchange (ETDEWEB)

Becker, James M.; Tagestad, Jerry D.; Duberstein, Corey A.; Downs, Janelle L.

2009-07-15

Proposed development of domestic energy resources, including wind energy, is expected to impact the sagebrush steppe ecosystem in the western United States. The greater sage-grouse relies on habitats within this ecosystem for survival, yet very little is known about how wind energy development may affect sage-grouse. The purpose of this report is to inform organizations of the impacts wind energy development could have on greater sage-grouse populations and identify information needed to fill gaps in knowledge.

[The variability of vegetation beginning date of greenness period in spring in the north-south transect of eastern China based on NOAA NDVI].

Science.gov (United States)

Wang, Zhi; Liu, Shi-rong; Sun, Peng-sen; Guo, Zhi-hua; Zhou, Lian-di

2010-10-01

NDVI based on NOAA/AVHRR from 1982 to 2003 are used to monitor variable rules for the growing season in spring of vegetation in the north-south transect of eastern China (NSTEC). The following, mainly, are included: (1) The changing speed of greenness period in spring of most regions in NSTEC is slow and correlation with the year is not distinct; (2) The regions in which greenness period in spring distinctly change mainly presented an advance; (3) The regions in which inter-annual fluctuation of greenness period in spring is over 10 days were found in 3 kinds of areas: the area covered with agricultural vegetation types; the areas covered with evergreen vegetation types; the areas covered with steppe vegetation types; (4) changes of vegetation greenness period in spring have spatio-temporal patterns.

Variability and climate change trend in vegetation phenology of recent decades in the Greater Khingan Mountain area, Northeastern China

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Huan Tang

2015-09-01

Full Text Available Vegetation phenology has been used in studies as an indicator of an ecosystem’s responses to climate change. Satellite remote sensing techniques can capture changes in vegetation greenness, which can be used to estimate vegetation phenology. In this study, a long-term vegetation phenology study of the Greater Khingan Mountain area in Northeastern China was performed by using the Global Inventory Modeling and Mapping Studies (GIMMS normalized difference vegetation index version 3 (NDVI3g dataset from the years 1982–2012. After reconstructing the NDVI time series, the start date of the growing season (SOS, the end date of the growing season (EOS and the length of the growing season (LOS were extracted using a dynamic threshold method. The response of the variation in phenology with climatic factors was also analyzed. The results showed that the phenology in the study area changed significantly in the three decades between 1982 and 2012, including a 12.1-day increase in the entire region’s average LOS, a 3.3-day advance in the SOS and an 8.8-day delay in the EOS. However, differences existed between the steppe, forest and agricultural regions, with the LOSs of the steppe region, forest region and agricultural region increasing by 4.40 days, 10.42 days and 1.71 days, respectively, and a later EOS seemed to more strongly affect the extension of the growing season. Additionally, temperature and precipitation were closely correlated with the phenology variations. This study provides a useful understanding of the recent change in phenology and its variability in this high-latitude study area, and this study also details the responses of several ecosystems to climate change.

Symptoms of main Callistephus chinensis L. Nees. diseases under Ukrainian urban ecosystem conditions of the forest-steppe zone

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Marchenko Alla

2017-12-01

Full Text Available Phytopathological monitoring of C. chinensis (L. Nees. has proven withering and root rot to be the dominating diseases in agrobiocenoses under Ukrainian urban ecosystem conditions of the forest-steppe zone. Their spread was 5,1 and 4 times more than one of spotting. The complex of plant pathogenic overground and underground microflora consists of 24 causative agents. B. cinerea, F. oxysporum, V. albo-atrum have been found on all the vegetative and reproductive parts of Callistephus chinensis (L. Nees., , Ph. cactorum – on plant overground and underground parts, Rh. solani – on underground parts and seeds, A. zinniae – on overground parts and seeds. The main C. chinensis (L. Nees. disease symptoms have been diagnosed (leaf spots, powdery mildew, verticillium wilt, rust, ramularia spot, septoria spots, botrytis blight, grey mold rot, late blight, fusarium blight, black stem.

75 FR 77801 - Endangered and Threatened Wildlife and Plants; Endangered Status for Dunes Sagebrush Lizard

Science.gov (United States)

2010-12-14

... public lands in Texas. It is evident that the dunes sagebrush lizard is still present at the park, but... expected to contribute to habitat loss, modification, or fragmentation in the future include wind and solar... and Solar Energy Development Eastern New Mexico and western Texas are highly suitable areas for wind...

Do container volume, site preparation, and field fertilization affect restoration potential of Wyoming big sagebrush?

Science.gov (United States)

Kayla R. Herriman; Anthony S. Davis; Kent G. Apostol; Olga. A. Kildisheva; Amy L. Ross-Davis; Kas Dumroese

2016-01-01

Land management practices, invasive species expansion, and changes in the fire regime greatly impact the distribution of native plants in natural areas. Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis), a keystone species in the Great Basin, has seen a 50% reduction in its distribution. For many dryland species, reestablishment efforts have...

Humid to arid to subhumid vegetation shift on Pilliga Sandstone, Ulungra Springs, New South Wales

Science.gov (United States)

Dodson, J. R.; Wright, R. V. S.

1989-09-01

The Pilliga Sandstone region of the northwest slope of New South Wales has a natural vegetation cover of sclerophyllous relatively closed to open forests with a largely heathy understorey, and a warm, subhumid and continental climate. Pollen analysis of spring-fed deposits gives a vegetation history extending from at least 30,000 yr B.P. to the late Holocene. Tree pollen became scarce after about 25,000 yr B.P. and an assemblage dominated by Chenopodiaceae, Liguliflorae, Tubuliflorae, and probably Poaceae developed. No similar assemblage is known from present pollen rain studies carried out in Australia. However, it clearly represents a treeless open shrub-steppe formation and therefore an arid or semiarid environment. The site thus provides evidence of an eastward late Pleistocene extension of the arid zone in Australia, and is the first full-glacial vegetation record between 20° and 35° latitude in Australia. The present vegetation cover did not become reestablished until the beginning of the Holocene, which raises questions about the form in which Pilliga Sandstone vegetation survived full-glacial conditions.

Using resistance and resilience concepts to reduce impacts of invasive annual grasses and altered fire regimes on the sagebrush ecosystem and greater sage-grouse: A strategic multi-scale approach

Science.gov (United States)

Jeanne C. Chambers; David A. Pyke; Jeremy D. Maestas; Mike Pellant; Chad S. Boyd; Steven B. Campbell; Shawn Espinosa; Douglas W. Havlina; Kenneth E. Mayer; Amarina Wuenschel

2014-01-01

This Report provides a strategic approach for conservation of sagebrush ecosystems and Greater Sage- Grouse (sage-grouse) that focuses specifically on habitat threats caused by invasive annual grasses and altered fire regimes. It uses information on factors that influence (1) sagebrush ecosystem resilience to disturbance and resistance to invasive annual grasses and (2...

Summary of science, activities, programs, and policies that influence the rangewide conservation of Greater Sage-Grouse (Centrocercus urophasianus)

Science.gov (United States)

Manier, D.J.; Wood, David J.A.; Bowen, Z.H.; Donovan, R.M.; Holloran, M.J.; Juliusson, L.M.; Mayne, K.S.; Oyler-McCance, S.J.; Quamen, F.R.; Saher, D.J.; Titolo, A.J.

2013-01-01

The Greater Sage-Grouse, has been observed, hunted, and counted for decades. The sagebrush biome, home to the Greater Sage-Grouse, includes sagebrush-steppe and Great Basin sagebrush communities, interspersed with grasslands, salt flats, badlands, mountain ranges, springs, intermittent creeks and washes, and major river systems, and is one of the most widespread and enigmatic components of Western U.S. landscapes. Over time, habitat conversion, degradation, and fragmentation have accumulated across the entire range such that local conditions as well as habitat distributions at local and regional scales are negatively affecting the long-term persistence of this species. Historic patterns of human use and settlement of the sagebrush ecosystem have contributed to the current condition and status of sage-grouse populations. The accumulation of habitat loss, persistent habitat degradation, and fragmentation by industry and urban infrastructure, as indicated by U.S. Fish and Wildlife Service (USFWS) findings, presents a significant challenge for conservation of this species and sustainable management of the sagebrush ecosystem. Because of the wide variations in natural and human history across these landscapes, no single prescription for management of sagebrush ecosystems (including sage-grouse habitats) will suffice to guide the collective efforts of public and private entities to conserve the species and its habitat. This report documents and summarizes several decades of work on sage-grouse populations, sagebrush as habitat, and sagebrush community and ecosystem functions based on the recent assessment and findings of the USFWS under consideration of the Endangered Species Act. As reflected here, some of these topics receive a greater depth of discussion because of the perceived importance of the issue for sagebrush ecosystems and sage-grouse populations. Drawing connections between the direct effects on sagebrush ecosystems and the effect of ecosystem condition on

The value of small habitat islands for the conservation of genetic variability in a steppe grass species

Science.gov (United States)

Wódkiewicz, Maciej; Dembicz, Iwona; Moysiyenko, Ivan I.

2016-10-01

The habitat loss and fragmentation due to agricultural land-conversion affected the steppe throughout its range. In Ukraine, 95% of steppe was destroyed in the last two centuries. Remaining populations are confined to few refuges, like nature reserves, loess ravines, and kurgans (small burial mounds), the latter being often subject to destruction by archeological excavations. Stipa capillata L. is a typical grass species of Eurasian steppes and extrazonal dry grasslands, that was previously used as a model species in studies on steppe ecology. The aim of our research was to assess genetic diversity of S. capillata populations within different types of steppe refuges (loess ravines, biosphere reserve, kurgan) and to evaluate the value of the latter group for the preservation of genetic diversity in the study species. We assessed genetic diversity of 266 individuals from 15 populations (nine from kurgans, three from loess ravines and three from Askania-Nova Biosphere Reserve) with eight Universal Rice Primers (URPs). Studied populations showed high intra-population variability (I: 0.262-0.419, PPB: 52.08-82.64%). Populations from kurgans showed higher genetic differentiation (ΦST = 0.247) than those from loess ravines (ΦST = 0.120) and the biosphere reserve (ΦST = 0.142). Although the diversity metrics were to a small extent lower for populations from kurgans than from larger refugia we conclude that all studied populations of the species still preserve high genetic variability and are valuable for protection. To what extent this pattern holds true under continuous fragmentation in the future must be carefully monitored.

[Recent fauna of ground-nesting birds in Transvolga steppes and its dynamics in the 20th century].

Science.gov (United States)

Oparin, M L

2008-01-01

It is shown that the structure of the ground-nesting bird fauna in Transvolga steppes has changed during the 20th century. The complex of lark species characteristic of true and dry steppe has disappeared because of climate change and impact of economic activity (the establishment of windbreak and roadside forest strips), which has provided for a sharp increase in the abundance of corvid birds.

Environmental Drivers of NDVI-Based Vegetation Phenology in Central Asia

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Jahan Kariyeva

2011-02-01

Full Text Available Through the application and use of geospatial data, this study aimed to detect and characterize some of the key environmental drivers contributing to landscape-scale vegetation response patterns in Central Asia. The objectives of the study were to identify the variables driving the year-to-year vegetation dynamics in three regional landscapes (desert, steppe, and mountainous; and to determine if the identified environmental drivers can be used to explain the spatial-temporal variability of these spatio-temporal dynamics over time. It was posed that patterns of change in terrestrial phenology, derived from the 8 km bi-weekly time series of Normalized Difference Vegetation Index (NDVI data acquired by the Advanced Very High Resolution Radiometer (AVHRR satellites (1981–2008, can be explained through a multi-scale analysis of a suite of environmental drivers. Multiple linear stepwise regression analyses were used to test the hypotheses and address the objectives of the study. The annually computed phenological response variables or pheno-metricstime (season start, season length, and an NDVI-based productivity metric were modeled as a function of ten environmental factors relating to soil, topography, and climate. Each of the three studied regional landscapes was shown to be governed by a distinctive suite of environmental drivers. The phenological responses of the steppe landscapes were affected by the year-to-year variation in temperature regimes. The phenology of the mountainous landscapes was influenced primarily by the elevation gradient. The phenological responses of desert landscapes were demonstrated to have the greatest variability over time and seemed to be affected by soil carbon content and year-to-year variation of both temperature regimes and winter precipitation patterns. Amounts and scales of observed phenological variability over time (measured through coefficient of variation for each pheno-metrictime in each of the regional

Improving Interdisciplinary Relationships in Primary Care with the Implementation of TeamSTEPPS

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Nicole Siddons

2016-03-01

Full Text Available A major challenge in healthcare is lack of interdisciplinary collaboration (O’Daniel & Rosenstein, 2008. The Institute of Medicine report, To Err is Human: Building a Safer Health System (1999, shows that errors often occur due to lapses in partnership and communication. This article describes the implementation of TeamSTEPPS, an evidence-based tool for optimizing staff relationships and partnership, in a clinic in which a change in the care model had affected interprofessional collaboration and teamwork, threatening healthcare outcomes and staff engagement. The implementation of TeamSTEPPS, customized using elements of IDEO’s (2015 Human-Centered Design, shifted the culture of the clinic towards partnership, resulting in improved staff perceptions of teamwork and statistically significant improvements in the quality of patient care.

Susceptibility and antibody response of Vesper Sparrows (Pooecetes gramineus) to West Nile virus: A potential amplification host in sagebrush-grassland habitat

Science.gov (United States)

Hofmeister, Erik K.; Dusek, Robert J.; Fassbinder-Orth, Carol; Owen, Benjamin; Franson, J. Christian

2016-01-01

West Nile virus (WNV) spread to the US western plains states in 2003, when a significant mortality event attributed to WNV occurred in Greater Sage-grouse ( Centrocercus urophasianus ). The role of avian species inhabiting sagebrush in the amplification of WNV in arid and semiarid regions of the North America is unknown. We conducted an experimental WNV challenge study in Vesper Sparrows ( Pooecetes gramineus ), a species common to sagebrush and grassland habitats found throughout much of North America. We found Vesper Sparrows to be moderately susceptible to WNV, developing viremia considered sufficient to transmit WNV to feeding mosquitoes, but the majority of birds were capable of surviving infection and developing a humoral immune response to the WNV nonstructural 1 and envelope proteins. Despite clearance of viremia, after 6 mo, WNV was detected molecularly in three birds and cultured from one bird. Surviving Vesper Sparrows were resistant to reinfection 6 mo after the initial challenge. Vesper sparrows could play a role in the amplification of WNV in sagebrush habitat and other areas of their range, but rapid clearance of WNV may limit their importance as competent amplification hosts of WNV.

Landscape characteristics and livestock presence influence common ravens: Relevance to greater sage-grouse conservation

Science.gov (United States)

Coates, Peter S.; Brussee, Brianne E.; Howe, Kristy; Gustafson, K. Ben; Casazza, Michael L.; Delehanty, David J.

2016-01-01

Common raven (Corvus corax; hereafter, raven) population abundance in the sagebrush steppe of the American West has increased threefold during the previous four decades, largely as a result of unintended resource subsidies from human land-use practices. This is concerning because ravens frequently depredate nests of species of conservation concern, such as greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse). Grazing by livestock in sagebrush ecosystems is common practice on most public lands, but associations between livestock and ravens are poorly understood. The primary objective of this study was to identify the effects of livestock on raven occurrence while accounting for landscape characteristics within human-altered sagebrush steppe habitat, particularly in areas occupied by breeding sage-grouse. Using data from southeastern Idaho collected during spring and summer across 3 yr, we modeled raven occurrence as a function of the presence of livestock while accounting for multiple landscape covariates, including land cover features, topographical features, and proximity to sage-grouse lek sites (breeding grounds), as well as site-level anthropogenic features. While accounting for landscape characteristics, we found that the odds of raven occurrence increased 45.8% in areas where livestock were present. In addition, ravens selected areas near sage-grouse leks, with the odds of occurrence decreasing 8.9% for every 1-km distance, increase away from the lek. We did not find an association between livestock use and distance to lek. We also found that ravens selected sites with relatively lower elevation containing increased amounts of cropland, wet meadow, and urbanization. Limiting raven access to key anthropogenic subsidies and spatially segregating livestock from sage-grouse breeding areas would likely reduce exposure of predatory ravens to sage-grouse nests and chicks.

Tools for Resilience Management: Multidisciplinary Development of State-and-Transition Models for Northwest Colorado

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Emily J. Kachergis

2013-12-01

Full Text Available Building models is an important way of integrating knowledge. Testing and updating models of social-ecological systems can inform management decisions and, ultimately, improve resilience. We report on the outcomes of a six-year, multidisciplinary model development process in the sagebrush steppe, USA. We focused on creating state-and-transition models (STMs, conceptual models of ecosystem change that represent nonlinear dynamics and are being adopted worldwide as tools for managing ecosystems. STM development occurred in four steps with four distinct sets of models: (1 local knowledge elicitation using semistructured interviews; (2 ecological data collection using an observational study; (3 model integration using participatory workshops; and (4 model simplification upon review of the literature by a multidisciplinary team. We found that different knowledge types are ultimately complementary. Many of the benefits of the STM-building process flowed from the knowledge integration steps, including improved communication, identification of uncertainties, and production of more broadly credible STMs that can be applied in diverse situations. The STM development process also generated hypotheses about sagebrush steppe dynamics that could be tested by future adaptive management and research. We conclude that multidisciplinary development of STMs has great potential for producing credible, useful tools for managing resilience of social-ecological systems. Based on this experience, we outline a streamlined, participatory STM development process that integrates multiple types of knowledge and incorporates adaptive management.

[Allelopathic effects of Artemisia sacrorum population in typical steppe based on niche theory].

Science.gov (United States)

Wang, Hui; Xie, Yong-Sheng; Cheng, Ji-Min; She, Xiao-Yan

2012-03-01

By using modified Levins niche width index and Pianka niche overlap index, this paper analyzed the ecological competition between constructive and dominant species in a typical steppe. The stem- and leaf extracts from the constructive species (Artemisia sacrorum) were utilized to study their allelopathic potential on the seed germination and plant growth of the dominant species (Stipa bungeana, Thymus mongolicus, S. grandis, and Leymus secalinus), and the ecological position of A. sacrorum in the steppe succession. In the steppe, S. bungeana had the widest niche width (0.99), followed by T. mongolicus (0.94), A. sacrorum (0.82), S. grandis (0.76), and L. secalinus (0.73). The niche overlap value between A. sacrorum and S. bungeana, S. bungeana and T. mongolicus, T. mongolicus and S. grandis, and A. sacrorum and T. mongolicus was 0.90, 0.95, 0.94, and 0.86, respectively. The allelopathic effects of A. sacrorum extracts varied with their concentration. For the seed germination, root growth, and shoot growth of the dominant species, A. sacrorum extracts showed a trend of promoting at low concentrations and inhibiting at high concentrations. The extracts of A. sacrorum had a stronger promotion effect on the root growth of S. bungeana than on that of T. mongolicus, but a stronger inhibition effect on the shoot growth of T. mongolicus than on that of S. bungeana. Methanol extracts had stronger allelopathic effects than aqueous extracts. The high niche overlap between A. sacrorum and S. bungeana, and T. mongolicus and S. grandis indicated that the steppe community would continue succession to S. bungeana, while A. sacrorum population was only an important transitional stage during the succession. The allelopathic effect of A. sacrorum played a driving role in the succession process.

Spatio-temporal dynamics of arbuscular mycorrhizal fungi associated with glomalin-related soil protein and soil enzymes in different managed semiarid steppes.

Science.gov (United States)

Wang, Qi; Bao, Yuying; Liu, Xiaowei; Du, Guoxin

2014-10-01

Temporal and spatial patterns of arbuscular mycorrhizal fungi (AMF) and glomalin and soil enzyme activities were investigated in different managed semiarid steppes located in Inner Mongolia, North China. Soils were sampled in a depth up to 30 cm from non-grazed, overgrazed, and naturally restored steppes from June to September. Roots of Leymus chinense (Trin.) Tzvel. and Stipagrandis P. Smirn. were also collected over the same period. Results showed that overgrazing significantly decreased the total mycorrhizal colonization of S. grandis; total colonization of L. chinensis roots was not significantly different in the three managed steppes. Nineteen AMF species belonging to six genera were isolated. Funneliformis and Glomus were dominant genera in all three steppes. Spore density and species richness were mainly influenced by an interaction between plant growth stage and management system (P soil depth. AMF species richness was significantly positively correlated with soil acid phosphatase activity, alkaline phosphatase activity, and two Bradford-reactive soil protein (BRSP) fractions (P soil glomalin and phosphatase activity in different managed semiarid steppes. Based on these observations, AMF communities could be useful indicators for evaluating soil quality and function of semiarid grassland ecosystems.

Do people with borderline personality disorder complicated by antisocial personality disorder benefit from the STEPPS treatment program?

Science.gov (United States)

Black, Donald W; Simsek-Duran, Fatma; Blum, Nancee; McCormick, Brett; Allen, Jeff

2016-08-01

Systems Training for Emotional Predictability and Problem Solving (STEPPS) is a group treatment for persons with borderline personality disorder (BPD). We describe results from two data sets on outcome in persons who participated in STEPPS with BPD alone or BPD plus antisocial personality disorder (ASPD). In Study 1, we examined the effect of comorbid ASPD on outcome in 65 persons with BPD who participated in a randomized controlled trial at an academic medical centre. In Study 2, we examined the effect of comorbid ASPD on outcome in 64 offenders with BPD who participated in STEPPS in correctional settings. All subjects were assessed for the presence of BPD and ASPD. In Study 1, subjects with ASPD experienced greater improvement in BPD symptoms, impulsiveness and global symptoms. In Study 2, offenders with ASPD experienced greater improvement in positive and negative behaviours and positive affectivity. We conclude that persons with BPD plus ASPD benefit from STEPPS in community and correctional settings. The findings suggest that persons with BPD plus ASPD show greater improvement in some domains than persons with BPD only. People with ASPD should not be automatically excluded from participation in the program. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

[Responses of soil fauna to environment degeneration in the process of wind erosion desertification of Hulunbeir steppe].

Science.gov (United States)

Lü, Shi-Hai; Lu, Xin-Shi; Gao, Ji-Xi

2007-09-01

To reveal the relationships between soil fauna and soil environmental factors in the process of steppe desertification, field survey combined with laboratory analysis was made to study the community structure, population density and biodiversity of soil fauna, and their relationships with the changes of soil organic matter, hydrolysable nitrogen, available phosphorus and moisture contents and soil pH at different stages of desertification of Hulunbeir steppe. The soil faunal specimens collected belonged to 4 phyla, 6 classes and 12 orders. Nematoda was the only dominant group of medium- and small-sized soil fauna, occupying 94.3% of the total, while Coleoptera and Hemiptera were the dominant groups of large-sized soil fauna, with the amount of 79.7%. The group amount, population density, diversity, and evenness of soil fauna had an obvious decreasing trend with the aggravation of steppe desertification. At serious stage of desertification, soil fauna vanished completely. The population density of soil fauna in 0-20 cm soil layer had significant linear correlations with soil nutrients and moisture contents, soil pH, and litter mass, indicating that soil fauna had stronger sensibility to the changes of soil environmental factors in the process of wind erosion desertification of Hulunbeir steppe.

History of fire and Douglas-fir establishment in a savanna and sagebrush-grassland mosaic, southwestern Montana, USA

Science.gov (United States)

Emily K. Heyerdahl; Richard F. Miller; Russell A. Parsons

2006-01-01

Over the past century, trees have encroached into grass- and shrublands across western North America. These include Douglas-fir trees (Pseudotsuga menziesii (Mirb.) Franco var. glauca (Beissn.) Franco) encroaching into mountain big sagebrush Nutt. ssp. vaseyana (Rydb.) Beetle) from stable islands of savanna in...

Analysis on Temporal-Spatial Changes of Vegetation Cverrge in Farming-Pastoral Ecotone of Inner Mongolia

Science.gov (United States)

Yan, X.; Li, J.; Yang, Z.

2018-04-01

Chen Barag Banner is located in the typical farming-pastoral ecotone of Inner Mongolia, and it is also the core area of Hulunbuir steppe. Typical agricultural and pastoral staggered production mode so that the vegetation growth of the region not only determines the local ecological environment, and animal husbandry production, but also have a significant impact on the whole Hulunbuir ecological security and economic development. Therefore, it is necessary to monitor the change of vegetation in this area. Based on 17 MODIS Normalized Difference Vegetation Index (NDVI) images, the authors reconstructed the dynamic change characteristics of Fraction vegetation coverage (FVC) in Chen Barag Banner from 2000 to 2016. In this paper, first at all, Pixel Decomposition Models was introduced to inversion FVC, and the time series of vegetation coverage was reconstructed. Then we analyzed the temporal-spatial changes of FVC by employing transition matrix. Finally, through image analyzing and processing, the results showed that the vegetation coverage in the study area was influenced by effectors including climate, topography and human actives. In the past 17 years, the overall effect of vegetation coverage showed a downward trend of fluctuation. The average vegetation coverage decreased from 58.81 % in 2000 to 48.14 % in 2016, and the area of vegetation cover degradation accounts for 40.09 % of the total change area. Therefore, the overall degradation trend was obvious.

Management Approaches to Accomplish Contemporary Livestock Production-Conservation Objectives in Shortgrass Steppe

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Traditional rangeland management in the shortgrass steppe has emphasized livestock production with moderate stocking rates, but alternative approaches will be needed to meet production objectives under increasing demands for conservation-oriented management. We investigated the utility of very inten...

Community Structure and Productivity in Western Mongolian Steppe

Directory of Open Access Journals (Sweden)

Kiyokazu Kawada

2014-12-01

Full Text Available The people of the Mongolian steppe have maintained a sustainable, nomadic lifestyle. However, several ecological processes are threatening their way of life. Ecological changan be detected through the analysis of quantitative and qualitative data. It is therefore, imperative to develop a sustainable rangeland management system aimed at combating desertifi cation. In this study we quantitatively and qualitatively describe several western Mongolian steppe plant communities by examining species composition, plant volume and community structure. Study sites were located in the Uvs and Khovd provinces and had all been affected by livestock grazing. A total of 48 species were found. Stipa krylovii , S . gobica , Cleistogenes songorica , Koeleria cristata and Ajania achilleoides were dominant. There was a signifi cant relationship between biomass and plant volume at all sites. Study sites were classifi ed into four groups using cluster analysis, based on the presence or absence of several species. More than 90% of plant volumes at all groups were perennial grasses and perennial forbs. The ratio of C 3 to C 4 plants at site 3 was reversed in comparison to the other sites. Species highly palatable to livestock were dominant at all sites. To ensure the sustainable use of biological resources in these arid areas, these fi ndings should be taken into account in designing land-use plans.

Lethal Encephalitozoon cuniculi genotype III infection in Steppe lemmings (Lagurus lagurus)

Czech Academy of Sciences Publication Activity Database

Hofmannová, L.; Sak, Bohumil; Jekl, V.; Mináriková, A.; Škorič, M.; Kváč, Martin

2014-01-01

Roč. 205, 1-2 (2014), s. 357-360 ISSN 0304-4017 R&D Projects: GA ČR(CZ) GAP505/11/1163 Institutional support: RVO:60077344 Keywords : Encephalitozoon cuniculi genotype III * Steppe lemmings * Lethal infection * PCR * Histology Subject RIV: EG - Zoology Impact factor: 2.460, year: 2014

Effects of Spring Drought on Carbon Sequestration, Evapotranspiration and Water Use Efficiency in the Songnen Meadow Steppe in Northeast China.

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Gang Dong; Jixun Guo; Jiquan Chen; Ge Sun; Song Gao; et al

2011-01-01

Global climate change projections suggest an increasing frequency of droughts and extreme rain events in the steppes of the Eurasian region. Using the eddy covariance method, we measured carbon and water balances of a meadow steppe ecosystem in Northeast China during 2 years which had contrasting precipitation patterns in spring seasons in 2007 and 2008. The meadow...

Plant age, communication, and resistance to herbivores: young sagebrush plants are better emitters and receivers.

Science.gov (United States)

Shiojiri, Kaori; Karban, Richard

2006-08-01

Plants progress through a series of distinct stages during development, although the role of plant ontogeny in their defenses against herbivores is poorly understood. Recent work indicates that many plants activate systemic induced resistance after herbivore attack, although the relationship between resistance and ontogeny has not been a focus of this work. In addition, for sagebrush and a few other species, individuals near neighbors that experience simulated herbivory become more resistant to subsequent attack. Volatile, airborne cues are required for both systemic induced resistance among branches and for communication among individuals. We conducted experiments in stands of sagebrush of mixed ages to determine effects of plant age on volatile signaling between branches and individuals. Young and old control plants did not differ in levels of chewing damage that they experienced. Systemic induced resistance among branches was only observed for young plants. Young plants showed strong evidence of systemic resistance only if airflow was permitted among branches; plants with only vascular connections showed no systemic resistance. We also found evidence for volatile communication between individuals. For airborne communication, young plants were more effective emitters of cues as well as more responsive receivers of volatile cues.

Sustainable covers for uranium mill tailings, USA: alternative design, performance, and renovation - 16369

International Nuclear Information System (INIS)

Waugh, William J.; Benson, Craig H.; Albright, William H.

2009-01-01

The U.S. Department of Energy Office of Legacy Management is investigating alternatives to conventional cover designs for uranium mill tailings. A cover constructed in 2000 near Monticello, Utah, USA, was a redundant design with a conventional low-conductivity composite cover overlain with an alternative cover designed to mimic the natural soil water balance as measured in nearby undisturbed native soils and vegetation. To limit percolation, the alternative cover design relies on a 160-cm layer of sandy clay loam soil overlying a 40- cm sand capillary barrier for water storage, and a planting of native sagebrush steppe vegetation to seasonally release soil water through evapotranspiration (ET). Water balance monitoring within a 3.0-ha drainage lysimeter, embedded in the cover during construction, provided convincing evidence that the cover has performed well over a 9-year period (2000- 2009). The total cumulative percolation, 4.8 mm (approximately 0.5 mm yr -1 ), satisfied a regulatory goal of -1 . Most percolation can be attributed to the very wet winter and spring of 2004-2005, when soil water content exceeded the storage capacity of the cover. Diversity, percent cover, and leaf area of vegetation increased over the monitoring period. Field and laboratory evaluations several years after construction show that soil structural development, changes in soil hydraulic properties, and development of vegetation patterns have not adversely impacted cover performance. A new test facility was constructed in 2008 near Grand Junction, Colorado, USA, to evaluate low-cost methods for renovating or transforming conventional covers into more sustainable ET covers. (authors)

Conservation and restoration of sagebrush ecosystems and sage-grouse: An assessment of USDA Forest Service Science

Science.gov (United States)

Deborah M. Finch; Douglas A. Boyce; Jeanne C. Chambers; Chris J. Colt; Kas Dumroese; Stanley G. Kitchen; Clinton McCarthy; Susan E. Meyer; Bryce A. Richardson; Mary M. Rowland; Mark A. Rumble; Michael K. Schwartz; Monica S. Tomosy; Michael J. Wisdom

2016-01-01

Sagebrush ecosystems are among the largest and most threatened ecosystems in North America. Greater sage-grouse has served as the bellwether for species conservation in these ecosystems and has been considered for listing under the Endangered Species Act eight times. In September 2015, the decision was made not to list greater sage-grouse, but to reevaluate its status...

Satellite tracking of a young Steppe Eagle from the United Arab ...

African Journals Online (AJOL)

Following recovery and successful rehabilitation, a young Steppe Eagle Aquila nipalensis was tagged with a 45 g GPS satellite transmitter to track its migration and identify potential wintering and summering areas of the species passing through the United Arab Emirates (UAE). The study is part of a larger study on ...

Conditions favouring Bromus tectorum dominance of endangered sagebrush steppe ecosystems

Science.gov (United States)

Reisner, Michael D.; Grace, James B.; Pyke, David A.; Doescher, Paul S.

2013-01-01

1. Ecosystem invasibility is determined by combinations of environmental variables, invader attributes, disturbance regimes, competitive abilities of resident species and evolutionary history between residents and disturbance regimes. Understanding the relative importance of each factor is critical to limiting future invasions and restoring ecosystems.

Decreased surface albedo driven by denser vegetation on the Tibetan Plateau

International Nuclear Information System (INIS)

Tian, Li; Zhang, Yangjian; Zhu, Juntao

2014-01-01

The Tibetan Plateau (TP) has fundamental ecological and environmental significance to China and Asia through its influence on regional and continental climates. In recent years, climate warming has caused unprecedented changes to land surface processes on the TP, which would unavoidably undermine the ecological and environmental functions of the TP. Among the numerous land surface processes potentially impacted by climate warming, the effect of vegetation greenness on surface energy balance is one of the most critical, but has been long ignored. In this study, we investigated the spatial and temporal patterns of land surface albedo (LSA) on the TP and evaluated the vegetation greenness in relation to patterns of LSA. We found that LSA has been decreasing in most of the vegetated grasslands on the TP from 2000 to 2013, as compared to a flat trend for desert area. The regions where LSA has been decreasing were spatially correlated to areas of increased vegetation greenness. Along rising altitude, LSA decreasing rate exhibited an overall decreasing trend. Across the TP, elevated vegetation greenness in grasslands acted as a primary factor pulling down LSA. The driving effects of vegetation greenness on LSA vary with grassland types, as revealed by a more significant relationship between vegetation greenness and LSA for the sparsely vegetated zone (i.e. steppe) than the more densely vegetated zone (i.e. meadow). Furthermore, the driving effect of vegetation greenness on LSA exhibited an obvious dependence on altitude as effects with rising altitude were relatively strong up to 3000 m, then weakened from 3500 m to 5000 m, and then the effects again increased from 5000 to 6000 m. The growing season LSA trend revealed in this study emphasizes the need to give greater attention to the growing season LSA flux in future surface energy balance studies. (letter)

Response and Resiliency of Wildlife and Vegetation to Large-Scale Wildfires and Climate Change in the North Cascades

Science.gov (United States)

Bartowitz, K.; Morrison, P.; Romain-Bondi, K.; Smith, C. W.; Warne, L.; McGill, D.

2016-12-01

Changing climatic patterns have affected the western US in a variety of ways: decreases in precipitation and snowpack, earlier spring snowmelt, and increased lightning strikes have created a drier, more fire-prone system, despite variability in these characteristics. Wildfires are a natural phenomenon, but have been suppressed for much of the past century. Effects of this evolving fire regime on native vegetation and wildlife are not well understood. Increased frequency and intensity of fires coupled with subsequent drought and extreme heat may inhibit or alter recovery of native ecosystems. We are currently investigating how a mega-fire has affected presence of western gray squirrels (Sciurus griseus, WGS) in the North Cascades, and the mortality, survival, and recovery of vegetation following these fires and extreme drought. The Methow Valley in WA experienced a record-breaking wildfire in 2014, which disturbed nearly 50% of priority habitat of the North Cascades population of WGS. WGS were studied at the same pre and post-fire plots. WGS were present at over half of the post-burn plots (58%). There was a significant difference in the number of WGS hair samples collected in different levels of remaining vegetation: the most in moderate, few in low, and none in high. Vegetation recovery was assessed through field data, and a chronosequence of satellite images and aerial photography. 75% of the 2014 fire burned non-forested vegetation. Ponderosa pine forests comprised the rest. The forests experienced about 70% initial mortality. Recovery of the forest appears slower than in the shrub-steppe. First year seedling survival was poor due to an extremely hot, dry summer, while second year survival appears higher due to a cool, moist spring and summer. One year after a large, multi-severity fire we found WGS may be more resilient to disturbance such as fires than previously thought. Future studies of WGS will help elucidate long-term response to large-scale fires, and

Evolutionary and ecological implications of genome size in the North American endemic sagebrushes and allies (Artemisia, Asteraceae)

Science.gov (United States)

Sonia Garcia; Miguel A. Canela; Teresa Garnatje; E. Durant McArthur; Jaume Pellicer; Stewart C. Sanderson; Joan Valles

2008-01-01

The genome size of 51 populations of 20 species of the North American endemic sagebrushes (subgenus Tridentatae), related species, and some hybrid taxa were assessed by flow cytometry, and were analysed in a phylogenetic framework. Results were similar for most Tridentatae species, with the exception of three taxonomically conflictive species: Artemisia bigelovii Gray...

Promoting Action on Research Implementation in Health Services framework applied to TeamSTEPPS implementation in small rural hospitals.

Science.gov (United States)

Ward, Marcia M; Baloh, Jure; Zhu, Xi; Stewart, Greg L

A particularly useful model for examining implementation of quality improvement interventions in health care settings is the PARIHS (Promoting Action on Research Implementation in Health Services) framework developed by Kitson and colleagues. The PARIHS framework proposes three elements (evidence, context, and facilitation) that are related to successful implementation. An evidence-based program focused on quality enhancement in health care, termed TeamSTEPPS (Team Strategies and Tools to Enhance Performance and Patient Safety), has been widely promoted by the Agency for Healthcare Research and Quality, but research is needed to better understand its implementation. We apply the PARIHS framework in studying TeamSTEPPS implementation to identify elements that are most closely related to successful implementation. Quarterly interviews were conducted over a 9-month period in 13 small rural hospitals that implemented TeamSTEPPS. Interview quotes that were related to each of the PARIHS elements were identified using directed content analysis. Transcripts were also scored quantitatively, and bivariate regression analysis was employed to explore relationships between PARIHS elements and successful implementation related to planning activities. The current findings provide support for the PARIHS framework and identified two of the three PARIHS elements (context and facilitation) as important contributors to successful implementation. This study applies the PARIHS framework to TeamSTEPPS, a widely used quality initiative focused on improving health care quality and patient safety. By focusing on small rural hospitals that undertook this quality improvement activity of their own accord, our findings represent effectiveness research in an understudied segment of the health care delivery system. By identifying context and facilitation as the most important contributors to successful implementation, these analyses provide a focus for efficient and effective sustainment of TeamSTEPPS

ANALYSIS ON TEMPORAL-SPATIAL CHANGES OF VEGETATION CVERRGE IN FARMING-PASTORAL ECOTONE OF INNER MONGOLIA

Directory of Open Access Journals (Sweden)

X. Yan

2018-04-01

Full Text Available Chen Barag Banner is located in the typical farming-pastoral ecotone of Inner Mongolia, and it is also the core area of Hulunbuir steppe. Typical agricultural and pastoral staggered production mode so that the vegetation growth of the region not only determines the local ecological environment, and animal husbandry production, but also have a significant impact on the whole Hulunbuir ecological security and economic development. Therefore, it is necessary to monitor the change of vegetation in this area. Based on 17 MODIS Normalized Difference Vegetation Index (NDVI images, the authors reconstructed the dynamic change characteristics of Fraction vegetation coverage（FVC）in Chen Barag Banner from 2000 to 2016. In this paper, first at all, Pixel Decomposition Models was introduced to inversion FVC, and the time series of vegetation coverage was reconstructed. Then we analyzed the temporal-spatial changes of FVC by employing transition matrix. Finally, through image analyzing and processing, the results showed that the vegetation coverage in the study area was influenced by effectors including climate, topography and human actives. In the past 17 years, the overall effect of vegetation coverage showed a downward trend of fluctuation. The average vegetation coverage decreased from 58.81 % in 2000 to 48.14 % in 2016, and the area of vegetation cover degradation accounts for 40.09 % of the total change area. Therefore, the overall degradation trend was obvious.

Five millennia of frozen vegetation and fire dynamics from an ice core in the Mongolian Altai

Science.gov (United States)

Brügger, S. O.; Gobet, E.; Sigl, M.; Osmont, D.; Papina, T.; Rudaya, N.; Schwikowski, M.; Tinner, W.

2017-12-01

The steppes of the Altai region in Central Asia are highly vulnerable to e.g. drought and overgrazing. Degradation during the past decades may undermine their resilience under global change conditions. Knowledge about past vegetation and fire dynamics in Mongolian Altai may contribute to a better understanding of future climate and human impact responses, however, paleo records are scarce in the area. Our novel high-alpine ice record from Tsambagarav glacier (48°39.338'N, 90°50.826'E, 4130m asl) in the Mongolian Altai provides unique paleoenvironmental informations at the landscape scale. The site is surrounded by dry steppes with scattered boreal tree stands. We assume that the site collects pollen and spores within several hundred km. The archive provides an exceptional temporal resolution with a sound chronology covering the past 5500 years (Herren et al. 2013). Microfossil analysis allows to reconstruct large-scale fire and vegetation dynamics to gain a better understanding of the timing and causes of late Holocene response variability. We use pollen as proxies for vegetation composition and structure, microscopic charcoal as a proxy for fire activity (Eichler et al. 2011), and spheroidal carbonaceous particles (SCPs or soots) as a proxy for fossil fuel combustion. Here we present the first microscopic charcoal record from Mongolia and link it to vegetation dynamics of the past. The reconstructed mid to late Holocene forest collapses likely in response to climate change underscore the vulnerability of relict forest ecosystems in the Mongolian Altai. Our multiproxy-study suggests that moisture is more important than temperature for forest preservation. The lacking resilience of vegetation to moisture changes in the past emphasizes the vulnerability of large forests in neighboring dry areas such as the Russian Altai, if global warming is associated to moisture declines as future projections forecast (IPCC; Climate Change 2013). References: Eichler et al. (2011

Late glacial vegetation and climate changes in the high mountains of Bulgaria (Southeast Europe)

International Nuclear Information System (INIS)

Bozilova, E.D.; Tonkov, S.B.

2005-01-01

Full text: The Late glacial vegetation history in the high mountains of Southern Bulgaria (Rila, Pirin, Western Rhodopes) is reconstructed by means of pollen analysis, plant macrofossils and radiocarbon dating of sediments from lakes and peat-bogs located between 1300 and 2200 m a.s.l. The vegetation response to the climate fluctuations after 13000 14 C yrs. BP in the Rila Mountains is bound for the first time to a detailed chronological framework. Two stadial and one interstadial phases are delimited analogous with the Oldest Dryas-Bolling/Allerod-Younger Dryas cycle for Western Europe. During the stadials mountain-steppe vegetation composed of Artemisia, Chenopodiaceae, Poaceae and other cold-resistant herbs dominated at high elevation with sparse stands of Pinus, Betula, and shrubland of Juniperus and Ephedra. The climate improvement in the interstadial resulted in the initial spread of deciduous and coniferous trees (Quercus, Tilia, Corylus, Carpinus, Abies, Picea) from their local refugia below 1000 m. The palaeoecological record from the climate deterioration during the Younger Dryas is documented in thin sections of the cores investigated. (author)

Holocene vegetation dynamics of Taiga forest in the Southern Altai Mountains documented by sediments from Kanas Lake

Science.gov (United States)

Huang, X.; Chen, F.

2016-12-01

The Chinese Altai is the southern limit of the Taiga forest of the continent, and regional vegetation dynamics during the Holocene will help us to understand regional climate changes, such as the Siberian High variations. Here we present a pollen-based vegetation and climate reconstruction from a well dated sediment core from Kanas Lake, a deep glacial moraine dammed lake in the Southern Altai Mountains (Chinese Altai). The 244-cm-long sequence spans the last 13,500 years, and the chronology is based on nine accelerator mass spectrometry radiocarbon dates from terrestrial plant macrofossils. At least five stages of regional vegetation history are documented: (i) From 13.5 to 11.7 ka (1 ka = 1000 cal yr BP), Kanas Lake region was occupied by steppe dominated by Artemisia, Chenopodiaceae and grass pollen, with low tree coverage. (ii) From 11.7 to 8.5 ka, regional forest build up dramatically indicated by increasing tree pollen percentages, including Picea, Larix, and the highest Junipers, with decreasing Artemisia and increasing Chenopodiaceae. (iii) From 8.5 to 7.2 ka, the forest around the lake became dense with the maximum content of Picea and Betula pollen types. And the steppe pollen types reached their lowest values. (iv) From 7.2 to 4 ka, as a typical tree species of Taiga forest, Larix pollen percentage became much higher than previous stage, and the sum of trees & shrubs pollen types decreased, which possibly indicated cooler and wetter climate (v) After 4 ka, trees & shrubs (e.g. Betula, Junipers) pollen types decreased, with increasing Artemisia and decreasing Chenopodiaceae, which might indicated more humid and cooler climate in the late Holocene. Comparing to the other pollen records in the Altai Mountains, Lake Grusha and Lake Hoton had recorded a slightly different process of vegetation evolution in the early Holocene, where forest was built up in the northern side of the Chinese Altai faster than that of the Kanas Lake area. And the difference could

CONTEMPORARY CHANGES OF THE CLIMATIC CONDITIONS OF THE CASPIAN SEMI-DESERT LANDSCAPES OF THE EASTERN CISCAUCASIA

Directory of Open Access Journals (Sweden)

Z. V. Ataev

2011-01-01

Full Text Available The article analyzes the changes in the hydrothermal conditions within the pricaspian littoral plains accumulation and denudation-accumulative in places aeolian landscapes saltwort, saltwort-sagebrush deserts and semi-deserts in light chestnut soils based on data from weather stations "Makhachkala" for years 1945-2005.Tendencies of changes in temperature, precipitation, and hydrothermal coefficient and coefficient of moisture are shown. Tendency of modern fluctuations suggests that the climatic conditions of the last period contribute to the development of dry steppes and significant deviations from the conditions of the previous period do not occur.

DYNAMICS OF ALGAE NUMBER AND BIOMASS OF STEPPE BIOGEOCOENOSES AND AGROCOENOSES IN KHERSON REGION

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Shcherbina V.V.

2011-12-01

Full Text Available Characteristics of daily dynamics of seaweeds abundance and biomass were determined for steppe biogeocoenosis and agrocoenosis of Biosphere reserve “Askaniya-Nova” in spring of 2011. Fluctuation ranges in seaweeds abundance and biomass have been registered.Analyzing the indices of total number and algae biomass in studied biogeocoenoses it should be noted that the maximal values of alga number in virgin soil steppe exceeded minimal in 3,3 times; biomasses - in 2,1. For virgin soil steppe of post-fire-induced development the relation between maximum and minimal value of total number of algae was up to 2,1; biomass - 2,4. For agrocoenosis we noted the largest ranges in variation of number and biomass. In conditions of dry-land arable land the maximum values of total number of alga exceeded minimal in 21,9 times; biomasses - in 8,7; for irrigated arable land - in 12,5 and 5,6 respectively.In soil samples, selected within the limits of virgin soil biogeocoenoses of biosphere reserve “Askania-Nova” and agrocoenosis of dry-land and irrigated arable land in biosphere reserve by direct count, the algae species of Bacillariophyta, Cyanophyta, Chlorophyta, Xanthophyta and Eustigmatophyta have been found. The largest contribution to number and biomass of algae belonged to Bacillariophyta. The number and biomass of agrocoenosis algae is more dynamic feature, than for algae of virgin soil biogeocoenoses.

Evaluating the outcomes of the STEPPS programme in a UK community-based population; implications for the multidisciplinary treatment of borderline personality disorder.

Science.gov (United States)

Hill, N; Geoghegan, M; Shawe-Taylor, M

2016-08-01

WHAT IS KNOWN ON THE SUBJECT?: Individuals with a diagnosis of Borderline Personality Disorder (BPD) now constitute a substantial portion of the caseload for community teams. Specialized treatments for BPD often consume a large portion of available psychology resources and also involve lengthy waiting lists. The STEPPS programme is a treatment approach which is growing in evidence, particularly in the US. However, further evidence for the effectiveness of this programme within the UK healthcare system is needed. The results of this study support the preliminary evidence for the effectiveness of STEPPS in a UK community-based population. A reduction in symptom severity was in evidence. Novel measures were used to build on previous evaluations of the STEPPS programme. These measures show a significant reduction in patients' affinity for unhelpful schemas, as well as an increase in patients' self-reported quality of life; an important perspective for a recovery focused approach to treatment. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: The STEPPS programme has shown its merit as an effective and more accessible treatment option for the community-based treatment of BPD, though some methodological limitations are noted. Furthermore, the results of this study demonstrate that STEPPS can be delivered effectively by teams of facilitators from different professional backgrounds who do not necessarily have extensive training in psychotherapeutic interventions. The result is a well-rounded and diverse skill set possessed by the team of facilitators, adding to the richness of the patient's recovery journey and leading to a more favourable spread of teams' resources. Aims & Background Systems Training for Emotional Predictability and Problem Solving (STEPPS) is a group treatment for individuals with a diagnosis of Borderline Personality Disorder (BPD) which has a growing evidence base, particularly in the US. Evidence is sparse for its use with UK populations, and this study seeks

How Networks of Informal Trails Cause Landscape Level Damage to Vegetation.

Science.gov (United States)

Barros, Agustina; Marina Pickering, Catherine

2017-07-01

When visitors are not constrained to remain on formal trails, informal trail networks can develop and damage plant communities in protected areas. These networks can form in areas with low growing vegetation, where formal trails are limited, where there is limited regulation and where vegetation is slow to recover once disturbed. To demonstrate the extent of impacts from unregulated recreational use, we assessed damage to alpine vegetation by hikers and pack animals in the highest protected area in the southern Hemisphere: Aconcagua Park, in the Andes. Within the 237 ha area surveyed in the Horcones Valley, over 19 km of trails were found, nearly all of which (94%) were informal. This network of trails resulted in the direct loss of 11.5 ha of vegetation and extensive fragmentation of alpine meadows (21 fragments) and steppe vegetation (68 fragments). When levels of disturbance off these trails were quantified using rapid visual assessments, 81% of 102 randomly located plots showed evidence of disturbance, with the severity of disturbance greatest close to trails. As a result, vegetation in 90% of the Valley has been damaged by visitor use, nearly all of it from unregulated use. These results highlight the extent to which informal trails and trampling off-trail can cause landscape damage to areas of high conservation value, and hence the importance of better regulation of visitor use. The methodology used for off-trail impact assessment can be easily applied or adapted for other popular protected areas where trampling off-trail is also an issue.

Sulfidogenesis in hypersaline chloride-sulfate lakes of Kulunda Steppe (Altai, Russia)

NARCIS (Netherlands)

Sorokin, D.Y.; Zacharova, E.E.; Pimenov, N.V.; Tourova, T.P.; Panteleeva, A.N.; Muyzer, G.

2012-01-01

The activity and culturable diversity of sulfidogens were investigated in anoxic sediments of four hypersaline lakes with pH 7.6-8.2 in the Kulunda Steppe (Altai, Russia). Sulfate reduction rates were low, varying from 0.1 to 6.0 nmol HS−/(cm3 h) with a maximum in the top 10 cm layer. Potential

Integrated disposal Facility Sagebrush Habitat Mitigation Project: FY2007 Compensation Area Monitoring Report

Energy Technology Data Exchange (ETDEWEB)

Durham, Robin E.; Sackschewsky, Michael R.

2007-09-01

This report summarizes the first year survival of sagebrush seedlings planted as compensatory mitigation for the Integrated Disposal Facility Project. Approximately 42,600 bare root seedlings and 26,000 pluglings were planted at a mitigation site along Army Loop Road in February 2007. Initial baseline monitoring occurred in March 2007, and first summer survival was assessed in September 2007. Overall survival was 19%, with bare root survival being marginally better than pluglings (21% versus 14%). Likely major factors contributing to low survival were late season planting and insufficient soil moisture during seedling establishment.

Linear objects impact on grassland degradation in the typical steppe region of China

NARCIS (Netherlands)

Li, Suying; Verburg, Peter H.; Lv, Shihai; Gao, Shangyu; Wu, Jingle

2011-01-01

Despite growing recognition of the issue of grassland degradation, few regional estimates of linear object impacts on grassland degradation [1]. We presented a methodology for evaluating regional impacts on steppe degradation from linear objects which were two uppermost types, rivers and roads, in

Bread winter wheat breeding (Triticum aestivum L. using spring varieties genepool in forest-steppe Environments of Ukraine

Directory of Open Access Journals (Sweden)

В. С. Кочмарський

2010-10-01

Full Text Available It is concluded by investigations that wheat crossing of various development types between themselves cause increase of formbuilding process in hybrid progeny, promoting the selection of practically valuable recombinats. The genotypes which present the practical valuable by complex of adaptive traits and properties have been selected by phenotype stability in the breeding process. The new bread winter wheat variety Pamyati Remesla developed with participation of spring wheat variety Hja 22139 (Finland has been proposed for including it into the Register of Plant varieties of Ukraine adapted for use in Steppe, Forest- Steppe and Woodland of Ukraine since 2010.

Data Report: Meteorological and Evapotranspiration Data from Sagebrush and Pinyon Pine/Juniper Communities at Pahute Mesa, Nevada National Security Site, 2011-2012

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Jasoni, Richard L [DRI; Larsen, Jessica D [DRI; Lyles, Brad F. [DRI; Healey, John M [DRI; Cooper, Clay A [DRI; Hershey, Ronald L [DRI; Lefebre, Karen J [DRI

2013-04-01

Pahute Mesa is a groundwater recharge area at the Nevada National Security Site. Because underground nuclear testing was conducted at Pahute Mesa, groundwater recharge may transport radionuclides from underground test sites downward to the water table; the amount of groundwater recharge is also an important component of contaminant transport models. To estimate the amount of groundwater recharge at Pahute Mesa, an INFIL3.0 recharge-runoff model is being developed. Two eddy covariance (EC) stations were installed on Pahute Mesa to estimate evapotranspiration (ET) to support the groundwater recharge modeling project. This data report describes the methods that were used to estimate ET and collect meteorological data. Evapotranspiration was estimated for two predominant plant communities on Pahute Mesa; one site was located in a sagebrush plant community, the other site in a pinyon pine/juniper community. Annual ET was estimated to be 310±13.9 mm for the sagebrush site and 347±15.9 mm for the pinyon pine/juniper site (March 26, 2011 to March 26, 2012). Annual precipitation measured with unheated tipping bucket rain gauges was 179 mm at the sagebrush site and 159 mm at the pinyon pine/juniper site. Annual precipitation measured with bulk precipitation gauges was 222 mm at the sagebrush site and 227 mm at the pinyon pine/juniper site (March 21, 2011 to March 28, 2012). A comparison of tipping bucket versus bulk precipitation data showed that total precipitation measured by the tipping bucket rain gauges was 17 to 20 percent lower than the bulk precipitation gauges. These differences were most likely the result of the unheated tipping bucket precipitation gauges not measuring frozen precipitation as accurately as the bulk precipitation gauges. In this one-year study, ET exceeded precipitation at both study sites because estimates of ET included precipitation that fell during the winter of 2010-2011 prior to EC instrumentation and the precipitation gauges started

Response of spatial vegetation distribution in China to climate changes since the Last Glacial Maximum (LGM)

Science.gov (United States)

Wang, Siyang; Xu, Xiaoting; Shrestha, Nawal; Zimmermann, Niklaus E.; Tang, Zhiyao; Wang, Zhiheng

2017-01-01

Analyzing how climate change affects vegetation distribution is one of the central issues of global change ecology as this has important implications for the carbon budget of terrestrial vegetation. Mapping vegetation distribution under historical climate scenarios is essential for understanding the response of vegetation distribution to future climatic changes. The reconstructions of palaeovegetation based on pollen data provide a useful method to understand the relationship between climate and vegetation distribution. However, this method is limited in time and space. Here, using species distribution model (SDM) approaches, we explored the climatic determinants of contemporary vegetation distribution and reconstructed the distribution of Chinese vegetation during the Last Glacial Maximum (LGM, 18,000 14C yr BP) and Middle-Holocene (MH, 6000 14C yr BP). The dynamics of vegetation distribution since the LGM reconstructed by SDMs were largely consistent with those based on pollen data, suggesting that the SDM approach is a useful tool for studying historical vegetation dynamics and its response to climate change across time and space. Comparison between the modeled contemporary potential natural vegetation distribution and the observed contemporary distribution suggests that temperate deciduous forests, subtropical evergreen broadleaf forests, temperate deciduous shrublands and temperate steppe have low range fillings and are strongly influenced by human activities. In general, the Tibetan Plateau, North and Northeast China, and the areas near the 30°N in Central and Southeast China appeared to have experienced the highest turnover in vegetation due to climate change from the LGM to the present. PMID:28426780

Vegetation Changes in the Permafrost Regions of the Qinghai-Tibetan Plateau from 1982-2012: Different Responses Related to Geographical Locations and Vegetation Types in High-Altitude Areas.

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Zhiwei Wang

Full Text Available The Qinghai-Tibetan Plateau (QTP contains the largest permafrost area in a high-altitude region in the world, and the unique hydrothermal environments of the active layers in this region have an important impact on vegetation growth. Geographical locations present different climatic conditions, and in combination with the permafrost environments, these conditions comprehensively affect the local vegetation activity. Therefore, the responses of vegetation to climate change in the permafrost region of the QTP may be varied differently by geographical location and vegetation condition. In this study, using the latest Global Inventory Modeling and Mapping Studies (GIMMS Normalized Difference Vegetation Index (NDVI product based on turning points (TPs, which were calculated using a piecewise linear model, 9 areas within the permafrost region of the QTP were selected to investigate the effect of geographical location and vegetation type on vegetation growth from 1982 to 2012. The following 4 vegetation types were observed in the 9 selected study areas: alpine swamp meadow, alpine meadow, alpine steppe and alpine desert. The research results show that, in these study areas, TPs mainly appeared in 2000 and 2001, and almost 55.1% and 35.0% of the TPs were located in 2000 and 2001. The global standardized precipitation evapotranspiration index (SPEI and 7 meteorological variables were selected to analyze their correlations with NDVI. We found that the main correlative variables to vegetation productivity in study areas from 1982 to 2012 were precipitation, surface downward long-wave radiation and temperature. Furthermore, NDVI changes exhibited by different vegetation types within the same study area followed similar trends. The results show that regional effects rather than vegetation type had a larger impact on changes in vegetation growth in the permafrost regions of the QTP, indicating that climatic factors had a larger impact in the permafrost

Statistical Models for Inferring Vegetation Composition from Fossil Pollen

Science.gov (United States)

Paciorek, C.; McLachlan, J. S.; Shang, Z.

2011-12-01

Fossil pollen provide information about vegetation composition that can be used to help understand how vegetation has changed over the past. However, these data have not traditionally been analyzed in a way that allows for statistical inference about spatio-temporal patterns and trends. We build a Bayesian hierarchical model called STEPPS (Spatio-Temporal Empirical Prediction from Pollen in Sediments) that predicts forest composition in southern New England, USA, over the last two millenia based on fossil pollen. The critical relationships between abundances of tree taxa in the pollen record and abundances in actual vegetation are estimated using modern (Forest Inventory Analysis) data and (witness tree) data from colonial records. This gives us two time points at which both pollen and direct vegetation data are available. Based on these relationships, and incorporating our uncertainty about them, we predict forest composition using fossil pollen. We estimate the spatial distribution and relative abundances of tree species and draw inference about how these patterns have changed over time. Finally, we describe ongoing work to extend the modeling to the upper Midwest of the U.S., including an approach to infer tree density and thereby estimate the prairie-forest boundary in Minnesota and Wisconsin. This work is part of the PalEON project, which brings together a team of ecosystem modelers, paleoecologists, and statisticians with the goal of reconstructing vegetation responses to climate during the last two millenia in the northeastern and midwestern United States. The estimates from the statistical modeling will be used to assess and calibrate ecosystem models that are used to project ecological changes in response to global change.

Changes in Biomass and Quality of Alpine Steppe in Response to N & P Fertilization in the Tibetan Plateau

Science.gov (United States)

Dong, Junfu; Cui, Xiaoyong; Wang, Shuping; Wang, Fang; Pang, Zhe; Xu, Ning; Zhao, Guoqiang; Wang, Shiping

2016-01-01

In the alpine steppe zone on the Central Tibetan Plateau, a large amount of area has been degraded due to natural and artificial factors. N & P fertilization is widely accepted to recover degraded pastures in other regions all over the world. However, it is not clear how alpine steppe communities respond to N & P fertilization, and what is the optimal application rate, in the perspective of forage production. To attempt to explore these questions, in July 2013, two fencing sites were designed in Baingoin County with 12 treatments of different levels of nitrogen (N0: 0; N1: 7.5 g m-2 yr-1; N2: 15 g m-2 yr-1) & phosphate (P0: 0; P1: 7.5 gP2O5 m-2 yr-1; P2: 15 gP2O5 m-2 yr-1; P3: 30 gP2O5 m-2 yr-1). The results indicated N&P addition was capable to ameliorate the quality of the two sites in the Tibetan Plateau steppe. Increasing N application level resulted in significant increment in Gramineae and total biomass in the two sites. P addition significantly improved the quantity of Compositae, total biomass and the biomasss of other species in site II, while it only significantly improved the total biomass in site I. Gramineae was much more sensitive to N-induced changes than P-induced changes, and this indicated N addition was better to ameliorate the quality of plateau steppe than P-induced changes. No strong evidence was found for critical threshold within 15 g N m-2 yr-1, and there was decreasing tendency when P addition rate was above 15 g m-2 yr-1. N&P has the potential to accelerate soil acidification, which improved the content of available K, likely as a result of nonsignificant correlation between biomass and soil moisture. This work highlights the the tradeoffs that exist in N and P addition in recovering degraded steppe. PMID:27223104

Population status, habitat associations, and distribution of the steppe polecat Mustela eversmanii in Europe

Czech Academy of Sciences Publication Activity Database

Šálek, Martin; Spassov, N.; Anděra, M.; Enzinger, K.; Ottlecz, B.; Hegyeli, Z.

2013-01-01

Roč. 58, č. 3 (2013), s. 233-244 ISSN 0001-7051 Institutional support: RVO:68081766 Keywords : Steppe polecat * Mustela eversmanii * Distribution * Habitat associations * Population status * Europe Subject RIV: EG - Zoology Impact factor: 1.161, year: 2013

Biomorphological traits of Callistephus chinensis (L. Nees cultivars under conditions of the Central Forest-Steppe zone of Ukraine

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С. М. Левандовська

2015-12-01

Full Text Available Purpose. Determining prospects of introducing Callistephus chinensis cultivars of foreign breeding for further cultivation under conditions of the Central Forest-Steppe zone of Ukraine. Methods. Field, laboratory, analytical and statistical ones. Results. Ten C. сhinensis cultivars of theGerman breeding were tested under conditions of the Central Forest-Steppe zone of Ukraine. Biomorphological traits of the varieties of five sort types were identified, and their comparative analysis was conducted. Seasonal dynamics of growth and development of cultivars in the growing area was studied. Conclusions. Cultivars with short and mean duration phases of development can be grown under conditions of the Central Forest-Steppe zone of Ukraine by direct sowing that does not affect their seed productivity and sowing quality of seeds. Seeds of late cultivars can reach complete maturity only in case of seedling use. C. chinensis cultivars of the German breeding have successfully passed the initial test for suitability to introduction into the studied area.

Divergent evapotranspiration partition dynamics between shrubs and grasses in a shrub-encroached steppe ecosystem.

Science.gov (United States)

Wang, Pei; Li, Xiao-Yan; Wang, Lixin; Wu, Xiuchen; Hu, Xia; Fan, Ying; Tong, Yaqin

2018-06-04

Previous evapotranspiration (ET) partitioning studies have usually neglected competitions and interactions between antagonistic plant functional types. This study investigated whether shrubs and grasses have divergent ET partition dynamics impacted by different water-use patterns, canopy structures, and physiological properties in a shrub-encroached steppe ecosystem in Inner Mongolia, China. The soil water-use patterns of shrubs and grasses have been quantified by an isotopic tracing approach and coupled into an improved multisource energy balance model to partition ET fluxes into soil evaporation, grass transpiration, and shrub transpiration. The mean fractional contributions to total ET were 24 ± 13%, 20 ± 4%, and 56 ± 16% for shrub transpiration, grass transpiration, and soil evaporation respectively during the growing season. Difference in ecohydrological connectivity and leaf development both contributed to divergent transpiration partitioning between shrubs and grasses. Shrub-encroachment processes result in larger changes in the ET components than in total ET flux, which could be well explained by changes in canopy resistance, an ecosystem function dominated by the interaction of soil water-use patterns and ecosystem structure. The analyses presented here highlight the crucial effects of vegetation structural changes on the processes of land-atmosphere interaction and climate feedback. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Assessment and prediction of the invasiveness of some alien plants in conditions of climate change in the steppe Dnieper region

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Y. V. Lykholat

2017-02-01

decade was not related to the ground conditions of the steppe Dnieper region. At the same time, changes in climatic conditions were favourable for some naturalized alien species because they have created the opportunity for seed reproduction of species away from the maternal plants. Alien species C. coggigria, P. serotina and A. syriaca were also the most sensitive to the influence of the climate changes. Consequently, these species have the greatest potential for increasing their level of invasiveness and endangering the biodiversity in the steppe Dnieper region under conditions of climate change. We suggest that a simultaneous initiation of invasiveness of these several alien species leads to an increase in the degree of threat to the diversity of natural plants in the region. The study results confirm the urgent need for analysis and forecasting of the consequences of introduction of alien species, in order to prevent the undesirable effects that this would bring for the region’s native vegetation.

Virtual TeamSTEPPS(®) Simulations Produce Teamwork Attitude Changes Among Health Professions Students.

Science.gov (United States)

Sweigart, Linda I; Umoren, Rachel A; Scott, Patrician J; Carlton, Kay Hodson; Jones, James A; Truman, Barbara; Gossett, Evalyn J

2016-01-01

The majority of the estimated 400,000 or more patient deaths per year in the United States are from preventable medical errors due to poor communication. Team training programs have been established to teach teamwork skills to health professions students. However, it is often challenging to provide this training at a physical site. A brief intervention using a virtual learning environment with TeamSTEPPS(®)-based scenarios is described. Using a pretest-posttest design, the effects on teamwork attitudes in 109 health professional students from two institutions and multiple disciplines were measured using the TeamSTEPPS Teamwork Attitudes questionnaire. Participants showed significant attitude changes in the categories of leadership, situation monitoring, mutual support, and communication (p ⩽ .05), with significance in four of the six indicator attitudes in the communication section at the p ⩽ .001 level. These findings indicate the potential impact that virtual learning experiences may have on teamwork attitudes in learners across professions on multiple campuses. Copyright 2016, SLACK Incorporated.

Productivity and CO2 exchange of Great Plains ecoregions. I. Shortgrass steppe: Flux tower estimates

Science.gov (United States)

Gilmanov, Tagir G.; Morgan, Jack A.; Hanan, Niall P.; Wylie, Bruce K.; Rajan, Nithya; Smith, David P.; Howard, Daniel M.

2017-01-01

The shortgrass steppe (SGS) occupies the southwestern part of the Great Plains. Half of the land is cultivated, but significant areas remain under natural vegetation. Despite previous studies of the SGS carbon cycle, not all aspects have been completely addressed, including gross productivity, ecosystem respiration, and ecophysiological parameters. Our analysis of 1998 − 2007 flux tower measurements at five Bowen ratio–energy balance (BREB) and three eddy covariance (EC) sites characterized seasonal and interannual variability of gross photosynthesis and ecosystem respiration. Identification of the nonrectangular hyperbolic equation for the diurnal CO2 exchange, with vapor pressure deficit (VPD) limitation and exponential temperature response, quantified quantum yield α, photosynthetic capacity Amax, and respiration rate rd with variation ranges (19 \\production from − 900 to + 700 g CO2 m− 2 yr− 1, indicating that SGS may switch from a sink to a source depending on weather. Comparison of the 2004 − 2006 measurements at two BREB and two parallel EC flux towers located at comparable SGS sites showed moderately higher photosynthesis, lower respiration, and higher net production at the BREB than EC sites. However, the difference was not related only to methodologies, as the normalized difference vegetation index at the BREB sites was higher than at the EC sites. Overall magnitudes and seasonal patterns at the BREB and the EC sites during the 3-yr period were similar, with trajectories within the ± 1.5 standard deviation around the mean of the four sites and mostly reflecting the effects of meteorology.

Water and CO2 fluxes over semiarid alpine steppe and humid alpine meadow ecosystems on the Tibetan Plateau

Science.gov (United States)

Wang, Lei; Liu, Huizhi; Shao, Yaping; Liu, Yang; Sun, Jihua

2018-01-01

Based on eddy covariance flux data from July 15, 2014, to December 31, 2015, the water and CO2 fluxes were compared over a semiarid alpine steppe (Bange, Tibetan Plateau) and a humid alpine meadow (Lijiang, Yunnan) on the Tibetan Plateau and its surrounding region. During the wet season, the evaporative fraction (EF) was strongly and linearly correlated with the soil water content (SWC) at Bange because of its sparse green grass cover. In contrast, the correlation between the EF at Lijiang and the SWC and the normalized difference vegetation index (NDVI) was very low because the atmosphere was close to saturation and the EF was relatively constant. In the dry season, the EF at both sites decreased with the SWC. The net ecosystem exchange (NEE) at Bange was largely depressed at noon, while this phenomenon did not occur at Lijiang. The saturated NEE at Bange was 24% of that at Lijiang. The temperature sensitivity coefficient of ecosystem respiration at Bange (1.7) was also much lower than that at Lijiang (3.4). The annual total NEE in 2015 was 21.8 and -230.0 g C m-2 yr-1 at Bange and Lijiang, respectively, and the NEE was tightly controlled by the NDVI at the two sites. The distinct differences in the water and CO2 fluxes at Bange and Lijiang are attributed to the large SWC difference and its effect on vegetation growth.

Effects of Applied Land Use Strategies on Farmland Soils in the Southwestern Siberian Kulunda-Steppe

Science.gov (United States)

Grunwald, Lars-Christian; Illiger, Patrick; Stephan, Eckart; Frühauf, Manfred

2014-05-01

The Kulunda steppe in southwestern Siberia is one of the most intensely used agricultural regions in the world. The study area of the KULUNDA project is the Kulunda steppe, which is a part of the conversion region created during the so called "virgin land campaign" in the soviet era. Nowadays it is characterized by widespread soil degradation. Despite the fact that agriculture is the basis of existence, land use practice is maladjusted to the local conditions. The widespread soil degradation and accordingly the decreased soil humus content have negative effects on crop yields in this region. With respect to climate change, the current study analyses the cause effect relationship between land use practice and soil properties. In particular, different methods of soil cultivation will be tested and for each of the cases the soil humus content, soil water, soil solute balance will be measured and compared. In addition, the possibilities of soil carbon sequestration capacity will be analyzed. Furthermore, the study aims to achieve properly adapted sustainable cropping systems to stabilize the yields and to increase the productivity of plant production per spatial unit in this high vulnerable dry farming region. In 2012 the long term field trials started at three test farms in different steppe biomes, containing different soil types from chernozems to kastanozems. Each of them is characterized by a negative water balance. Successfully running cropping models, such as crop rotation, tilling intensity, plant protection and nutrition strategies from south Canadian steppe regions were adapted to regional agronomic needs. The traditional Russian cultivation system will be compared with two modern systems, including no-tillage methods on specially randomized test plots. Additionally, these plots are equipped with soil moisture monitoring systems to analyze the soil water content in different depths under the different cropping methods. The expected results will not only deepen

Changes in vegetation since the late glacial on peat bog in the Small Carpathians

International Nuclear Information System (INIS)

Ciernikova, M.

2014-01-01

Mires are ecosystems accumulating high amount of organic matter with preserved micro- and macro-fossils. Thus they can serve as natural archives allowing reconstruction of local vegetation and landscape development. Main aim of this study was to bring evidence of the whole Holocene history of mire birch woodland located on the ridge of the Male Karpaty Mts (SW Slovakia) using pollen analysis. One peat core was sampled from the middle part containing the whole Holocene sequence. The local development of study site started with small lake in a terrain depression, which arose at the end of the Late Glacial (Middle Dryas). The Late Glacial landscape was mosaic of birch-pine forests on suitable places and Artemisia steppes. Early Holocene is characterized by steep decline of pine and increase of Corylus and other mesophilous trees (Quercus, Tilia, Ulmus, Fraxinus). Fagus started dominate in middle Holocene (about 5000 cal BP). The recent vegetation established only several hundred years ago (ca 500 cal. BP), when birch started dominate. (author)

Transport of biologically important nutrients by wind in an eroding cold desert

Science.gov (United States)

Sankey, Joel B.; Germino, Matthew J.; Benner, Shawn G.; Glenn, Nancy F.; Hoover, Amber N.

2012-01-01

Wind erosion following fire is an important landscape process that can result in the redistribution of ecologically important soil resources. In this study we evaluated the potential for a fire patch in a desert shrubland to serve as a source of biologically important nutrients to the adjacent, downwind, unburned ecosystem. We analyzed nutrient concentrations (P, K, Ca, Mg, Cu, Fe, Mn, Al) in wind-transported sediments, and soils from burned and adjacent unburned surfaces, collected during the first to second growing seasons after a wildfire that burned in 2007 in Idaho, USA in sagebrush steppe; a type of cold desert shrubland. We also evaluated the timing of potential wind erosion events and weather conditions that might have contributed to nutrient availability in downwind shrubland. Findings indicated that post-fire wind erosion resulted in an important, but transient, addition of nutrients on the downwind shrubland. Aeolian sediments from the burned area were enriched relative to both the up- and down-wind soil and indicated the potential for a fertilization effect through the deposition of the nutrient-enriched sediment during the first, but not second, summer after wildfire. Weather conditions that could have produced nutrient transport events might have provided increased soil moisture necessary to make nutrients accessible for plants in the desert environment. Wind transport of nutrients following fire is likely important in the sagebrush steppe as it could contribute to pulses of resource availability that might, for example, affect plant species differently depending on their phenology, and nutrient- and water-use requirements.

Trends and patterns of anthropogenic evolution of chernozems in lands of agricultural afforestation within the territory of forest-steppe in the center of eastern Europe

Science.gov (United States)

The anthropogenic evolution of chernozems as a result of plowing and the creation of forest shelterbelts on three meadow-steppe areas of forest-steppe were studied. It was established, that in all areas there are similar patterns, caused by the transformation of virgin soils into arable soils and vi...

Ethnobotanical survey of medicinal plants used by nomadic peoples in the Algerian steppe.

Science.gov (United States)

Miara, Mohamed Djamel; Bendif, Hamdi; Ait Hammou, Mohammed; Teixidor-Toneu, Irene

2018-06-12

This study is the first ethnobotanical survey focusing on the herbal medicines traditionally used by the nomadic community of the Algerian steppe, identifying new medicinal plants and uses from one of the most characteristic indigenous populations in Algeria. Moreover, the study contributes to the understanding of transmission of medicinal plant knowledge in the Mediterranean basin. This work aims to document the phytotherapeutical knowledge and practice of the nomadic community of the Algerian steppe, and compare it with neighbouring sedentary populations and Mediterranean historical texts. Through this, the study strives to evaluate processes of transmission of knowledge among this population, for whom written sources have been largely unavailable. Ethnobotanical surveys were carried out during two years (2015-2017). In total, 73 informants from nomadic populations were interviewed in several steppe regions including areas in the administrative departments of Tiaret, Saida, Naama, Djelfa and M'sila. Structured interviews about medicinal plant knowledge were combined with guided tours with the informants. Prior informed consent was always obtained. The surveys allowed for the collection of sociodemographic data and traditional knowledge about medicinal plants and their uses. Informant Consensus Factor (F IC ) was calculated to evaluate agreement among informants. Results were compared to existing literature to evaluate similarities between this nomadic medicinal flora, that of neighbouring communities and historical texts and identify new plant citations and uses. Among Algerian nomadic communities, herbal remedies are used mostly by women and elders, who are often illiterate. We identified 97 taxa of medicinal plants belonging to 42 botanical families, importantly Lamiaceae, Asteraceae and Apiaceae, like in neighbouring communities. The most common plant parts and method of preparation are also shared with neighbouring populations. New uses are described for 25

Encapsulating model complexity and landscape-scale analyses of state-and-transition simulation models: an application of ecoinformatics and juniper encroachment in sagebrush steppe ecosystems

Science.gov (United States)

O'Donnell, Michael

2015-01-01

State-and-transition simulation modeling relies on knowledge of vegetation composition and structure (states) that describe community conditions, mechanistic feedbacks such as fire that can affect vegetation establishment, and ecological processes that drive community conditions as well as the transitions between these states. However, as the need for modeling larger and more complex landscapes increase, a more advanced awareness of computing resources becomes essential. The objectives of this study include identifying challenges of executing state-and-transition simulation models, identifying common bottlenecks of computing resources, developing a workflow and software that enable parallel processing of Monte Carlo simulations, and identifying the advantages and disadvantages of different computing resources. To address these objectives, this study used the ApexRMS® SyncroSim software and embarrassingly parallel tasks of Monte Carlo simulations on a single multicore computer and on distributed computing systems. The results demonstrated that state-and-transition simulation models scale best in distributed computing environments, such as high-throughput and high-performance computing, because these environments disseminate the workloads across many compute nodes, thereby supporting analysis of larger landscapes, higher spatial resolution vegetation products, and more complex models. Using a case study and five different computing environments, the top result (high-throughput computing versus serial computations) indicated an approximate 96.6% decrease of computing time. With a single, multicore compute node (bottom result), the computing time indicated an 81.8% decrease relative to using serial computations. These results provide insight into the tradeoffs of using different computing resources when research necessitates advanced integration of ecoinformatics incorporating large and complicated data inputs and models. - See more at: http

Idaho National Engineering and Environmental Laboratory Wildland Fire Management Environmental Assessment

Energy Technology Data Exchange (ETDEWEB)

Irving, John S

2003-04-01

DOE prepared an environmental assessment (EA)for wildland fire management activities on the Idaho National Engineering and Environmental Laboratory (INEEL) (DOE/EA-1372). The EA was developed to evaluate wildland fire management options for pre-fire, fire suppression, and post fire activities. Those activities have an important role in minimizing the conversion of the native sagebrush steppe ecosystem found on the INEEL to non-native weeds. Four alternative management approaches were analyzed: Alternative 1 - maximum fire protection; Alternative 2 - balanced fire protection; Alternative 2 - balanced fire protection; Alternative 3 - protect infrastructure and personnel; and Alternative 4 - no action/traditional fire protection.

Idaho National Engineering and Environmental Laboratory Wildland Fire Management Environmental Assessment - April 2003

Energy Technology Data Exchange (ETDEWEB)

Irving, J.S.

2003-04-30

DOE prepared an environmental assessment (EA)for wildland fire management activities on the Idaho National Engineering and Environmental Laboratory (INEEL) (DOE/EA-1372). The EA was developed to evaluate wildland fire management options for pre-fire, fire suppression, and post fire activities. Those activities have an important role in minimizing the conversion of the native sagebrush steppe ecosystem found on the INEEL to non-native weeds. Four alternative management approaches were analyzed: Alternative 1 - maximum fire protection; Alternative 2 - balanced fire protection; Alternative 2 - balanced fire protection; Alternative 3 - protect infrastructure and personnel; and Alternative 4 - no action/traditional fire protection.

Climate Compatible Development in the Mongolia Steppe: analysis of vulnerability and adaptation response to global changes

Science.gov (United States)

Ojima, D. S.; Togtokh, C.; Galvin, K. A.

2015-12-01

INTRODUCTION: Climate change and variability, market and policy changes are shaping pastoral communities' decisions on what pathways their future livelihoods will take and how the steppe landscapes and river basins, are managed. Recent droughts and damaging winter storms (zuds) of the past two decades have exacerbated the situation and undermined the natural capital on which the pastoral livelihoods depend upon. River basins are critical natural resources well-being of social-ecological systems in Mongolia. River basins provide the ecosystem services which support pastoral communities and industrial and urban development. Green development strategies are strongly dependent on water resources. Consequently, integrated planning of river basin management is needed to maintain these critical ecosystem services to meet the multiple needs of livelihoods of communities in these basins and to support sustainable development activities within the basins. For this study our team worked in nine sums (i.e., county level administrative areas) in three river basins in two provinces (aimags) to collect household data from 144 households. We also collected census data from the aimags and national level to understand trends at the level of ecosystems and river basins. We have selected 3 sums in each river basis, representing forest steppe, steppe and desert steppe regions for comparison across river basins and ecological zones. FINDINGS: Integrated planning efforts would be enhanced through, one, use of a social-ecological framework and, two, the development of a cross-ministerial working group to address natural resource considerations. Across the three basins agriculture, pastoral, industrial, and urban needs vie for similar ecosystem services. The natural capital and ecosystem services of these basins need to be assessed to understand the vulnerability and capacity of the resources. The most frequently listed "best coping strategy" across all ecosystem types was for herders to

The Kazakh Steppe at the Turn of the 18th-19th Centuries: Reforms and Projects

Directory of Open Access Journals (Sweden)

Vasilyev Dmitriy Valentinovich

2015-12-01

Full Text Available The following article is written on the basis of published and archival sources. O. Igelstrom’s reforms, and also the projects for government of the Kazakh Steppe prepared by some Russian officials, officers and ecclesiastics are considered by the author. Their singularities and differences are shown; the conclusion on their influence on the Russian policy in the region is drawn. The main attention is paid to reforms of O. Igelstrom who created the administrative institutions founded on local political tradition in the Small Horde. He intended to use them as instruments for the Russian influence in the Kazakh steppe. Local patrimonial leaders turned into government officials. But this experience was unsuccessful. Traditional Kazakh institutions didn’t conform to requirements of the Russian administration. The failure of those reforms provoked search of new models for the organization of Kazakh steppe’s administration. The Orenburg official D. Grankin suggested to refuse patrimonial division of the Small horde and to divide it according to the territorial principle. He suggested to include Russian officials and mullahs in all administrative bodies and to strengthen them by military detachments. The chief of the Siberian Lines Ya. Bouver suggested introducing the territorial division in the Middle Horde close to the imperial one. Expansion of the Russian sociocultural codes to the region was the main idea of his project. In the article considerable attention is paid to proposals of the Orenburg mufti M. Khusainov. He suggested to divide the Small Horde into two parts taking into account the patrimonial principle. The khan with sultans and advisers had to be at the head of each part. The deputies elected by notable Kazakhs had to become a sort of representative body in the part. The group of the armed Russian Muslims had to support safety in the Steppe. The Russian participation in internal administration of the Steppe was offered to minimize

ISOTOPES, PLANTS, AND RESERVOIR EFFECTS : CASE STUDY FROM THE CASPIAN STEPPE BRONZE AGE

NARCIS (Netherlands)

Shishlina, N.; Zazovskaya, E.; van der Plicht, J.; Sevastyanov, V.; Boaretto, E.; Rebollo Franco, N.R.

2012-01-01

Bronze Age human and animal bone collagen from several steppe Bronze Age cultures (i.e. Early Catacomb, East and West Manych Catacomb, and Lola cultures) shows large variations in delta C-13 and delta N-15 values. In general, we observed that the older the sample, the lower the delta C-13 and delta

A comparative study of ancient sedimentary DNA, pollen and macrofossils from permafrost sediments of northern Siberia reveals long-term vegetational stability

DEFF Research Database (Denmark)

Jørgensen, Tina; Haile, James Seymour; Möller, Per

2012-01-01

and the determination of indicator species to describe environmental changes. Combining data from all three proxies reveals an area continually dominated by a mosaic vegetation of tundra-steppe, pioneer and wet-indicator plants. Such vegetational stability is unexpected, given the severe climate changes taking place...... in the Northern Hemisphere during this time, with changes in average annual temperatures of >22 °C. This may explain the abundance of ice-age mammals such as horse and bison in Taymyr Peninsula during the Pleistocene and why it acted as a refugium for the last mainland woolly mammoth. Our finding reveals...... the benefits of combining sedaDNA, pollen and macrofossil for palaeovegetational reconstruction and adds to the increasing evidence suggesting large areas of the Northern Hemisphere remained ecologically stable during the Late Pleistocene....

Using vegetation structure estimates derived from multi-source remote sensing to predict dynamics of a semi-arid ecosystem in the western US

Science.gov (United States)

Shrestha, R.; Mitchell, J. J.; Glenn, N. F.; Flores, A. N.

2014-12-01

The distribution of species and vegetation types across the western US are expected to shift in response to climate change. Previous studies have documented the change in fire regime and the increasing fire-invasive grass cycle occurring in the western U.S. The change in vegetation structure due to climate change and invasive species alters the fuel load, making these ecosystems vulnerable to high-severity fire. Synergistic remote sensing data, such as hyperspectral data and high-resolution lidar, can be leveraged to capture the composition and structural variability of short-statured semiarid vegetation (e.g. sagebrush, annual grasses). We use a random-forests based fusion technique to integrate multi-source airborne data (hyperspectral and LiDAR) and generate spatially-explicit estimates of vegetation composition and structure (biomass, cover, density, height, LAI) and associated uncertainty across a climate and elevation gradient in southern Idaho. The results will be used to initialize an individual-based terrestrial biosphere model (Ecosystem Demography, ED2) and estimate structural dynamics under future scenarios. This study will provide a basis for understanding feedback mechanisms related to changing climate conditions, fire regimes and patterns of non-native plant invasion. The forthcoming field and remote sensing collection campaigns are also designed for parameterizing a dryland shrub plant functional type in the ED2 model.

Chorological classification approach for species and ecosystem conservation practice

Science.gov (United States)

Rogova, T. V.; Kozevnikova, M. V.; Prokhorov, V. E.; Timofeeva, N. O.

2018-01-01

The habitat type allocation approach based on the EUNIS Habitat Classification and the JUICE version 7 software is used for the conservation of species and ecosystem biodiversity. Using the vegetation plots of the Vegetation Database of Tatarstan, included in the EVA (European Vegetation Archive) and GIVD (Global Index of Vegetation-plots Databases) types of habitats of dry meadows and steppes are distinguished by differing compositions of the leading families composing their flora - Asteraceae, Fabaceae, Poaceae and Rosaceae. E12a - Semi-dry perennial calcareous grassland, and E12b - Perennial calcareous grassland and basic steppes were identified. The selected group of relevés that do not correspond to any of the EUNIS types can be considered specific for ecotone forest-steppe landscapes of the southeast of the Republic of Tatarstan. In all types of studied habitats, rare and protected plant species are noted, most of which are South-East-European-Asian species.

INITIAL BREEDING MATERIAL OF VEGETABLE BEAN FOR DEVELOPMENT OF EARLY-RIPENING VARIETIES IN NORTH PART OF FOREST STEPPE OF THE UKRAINE

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E. N. Grishenko

2015-01-01

Full Text Available The collection of vegetable bean varieties was screened for duration of vegetative and interstage periods. The initial breeding material as a source of early-ripeness was selected.

Mapping the recovery of the burnt vegetation by classifying pre- and post-fire spectral indices

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M. A Peña

2017-12-01

Full Text Available This study analyzed the state of recovery of the burnt vegetation in the National Park of Torres del Paine between December, 2011 and March, 2012. The calculation and comparison of the NVDI (normalized difference vegetation index of the burnt area throughout a time series of 24 Landsat images acquired before, during and after the fire (2009- 2015, showed the temporal variation in the biomass levels of the burnt vegetation. The subsequent classification and comparison of the spectral indices: NDVI, NBR (normalized burnt ratio and NDWI (normalized difference water index on a full-data available and phenologically matched pre- and post-fire image pair (acquired in October 2009 and 2014, enabled to analyze and mapping the state of recovery of the burnt vegetation. The results show that the area of the lowest classes of all the spectral indices of the pre-fire date became the most dominant on the post-fire date. The pre- and post- fire NDVI class crossing by a confusion matrix showed that the highest and most prevailing pre-fire NDVI classes, mostly corresponding to hydromorphic forests and Andean scrubs, turned into the lowest class in 2014. The remaining area, comprising Patagonian steppe, reestablished its biomass levels in 2014, mostly exhibiting the same pre-fire NDVI classes. These results may provide guidelines to monitor and manage the regeneration of the vegetation impacted by this fire.

Influence of habitat on behavior of Towndsend's ground squirrels (Spermophilus townsendii)

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Sharpe, Peter B.; Van Horne, Beatrice

1998-01-01

Trade-offs between foraging and predator avoidance may affect an animal's survival and reproduction. These trade-offs may be influenced by differences in vegetative cover, especially if foraging profitability and predation risk differ among habitats. We examined above-ground activity of Townsend's ground squirrels (Spermophilus townsendii) in four habitats in the Snake River Birds of Prey National Conservation Area in southwestern Idaho to determine if behavior of ground squirrels varied among habitats, and we assessed factors that might affect perceived predation risk (i. e. predator detectability, predation pressure, population density). The proportion of time spent in vigilance by ground squirrels in winterfat (Krascheninnikovia lanata) and mosaic habitats of winterfat-sagebrush (Artemisia tridentata) was more than twice that of ground squirrels in burned and unburned sagebrush habitats. We found no evidence for the 'many-eyes' hypothesis as an explanation for differences in vigilance among habitats. Instead, environmental heterogeneity, especially vegetation structure, likely influenced activity budgets of ground squirrels. Differences in vigilance may have been caused by differences in predator detectability and refuge availability, because ground squirrels in the winterfat and mosaic habitats also spent more time in upright vigilant postures than ground squirrels in burned-sagebrush or sagebrush habitats. Such postures may enhance predator detection in low-growing winterfat.

Efectos del pastoreo sobre el suelo y la vegetación en la Estepa Patagónica Grazing effects on soil and vegetation in the Patagonian Steppe

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Juan José Gaitán

2009-12-01

Full Text Available La ganadería ovina durante más de 100 años produjo grandes cambios en los ecosistemas y es una de las principales causas de la desertificación en la estepa patagónica. Este trabajo tiene por objetivo evaluar los efectos del pastoreo sobre el suelo y la vegetación mediante la aplicación de una versión modificada de la metodología «Landscape Function Analysis» desarrollada en Australia. El estudio se realizó en siete sitios con distintos niveles de degradación por pastoreo en Pilcaniyeu (noroeste de Río Negro: tres clausurados al pastoreo (CLA, tres bajo pastoreo moderado (PM y uno bajo pastoreo intenso (PI. Se evaluaron indicadores de la composición florística y estructura espacial de la vegetación, del estado de la superficie del suelo en los interparches, los cuales fueron integrados en tres Índices de Función (Estabilidad -EST-, Infiltración -INFy Reciclaje de nutrientes -NUT- y el stock de carbono orgánico (CO. Al incrementarse la intensidad de pastoreo se observó una disminución en la cobertura basal de la vegetación (47,4; 23,2 y 17,4% en CLA, PM y PI, respectivamente, parches vegetados más distanciados entre sí (61,9; 117,9 y 181,7 cm, menor cobertura de gramíneas palatables (26,3; 3,4 y 2,1% y mayor de no palatables (4,4; 15,8 y 17,6%. También se observó una tendencia a disminuir en los Índices de Función del suelo (EST: 43,0; 42,3 y 36,2; INF: 48,3; 41,7 y 36,2; NUT: 33,1; 23,5 y 18,1 y del CO (33,8; 26,5 y 7,9 t/ha al incrementarse la intensidad de pastoreo. Se requieren más estudios para adaptar esta metodología a las condiciones de Patagonia y testear con datos experimentales de que manera los índices reflejan adecuadamente los procesos y funciones de estos ecosistemas.More than 100 years of sheep breeding has caused profound changes to ecosystems and is one of the main causes of desertification in the Patagonian steppe. The aim of this study was to evaluate sheep grazing effects on soils and

Growth and development of sugar sorghum (Sorghum saccharatum L. Pers. plants at different terms of sowing and seeding depth in the Forest-Steppe of Ukraine

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Л. А. Герасименко

2013-02-01

Full Text Available The article features the results of research on phenological observations, biometric parameters of growth and development of the plants of sugar sorghum Silosnoe 42 variety during the vegetation at different terms of sowing and seeding depth in the Forest-Steppe of Ukraine. In particular, we show data on ground germination capacity of the seeds, the duration of the interphase periods, tillering, plant height and the diameter of the stem. It was established that the planting of sugar sorghum in mid-May (the third sowing date to the seeding depth of 4...6 cm enabled better plant development, as well as in these conditions the maximum values of plant growth and development were registered compared to the other test editions. Therefore, were would suggest the third term of sowing and seed depth 4...6 cm for growing the crop in this area.

Changes in vegetation phenology on the Mongolian Plateau and their climatic determinants.

Science.gov (United States)

Miao, Lijuan; Müller, Daniel; Cui, Xuefeng; Ma, Meihong

2017-01-01

Climate change affects the timing of phenological events, such as the start, end, and length of the growing season of vegetation. A better understanding of how the phenology responded to climatic determinants is important in order to better anticipate future climate-ecosystem interactions. We examined the changes of three phenological events for the Mongolian Plateau and their climatic determinants. To do so, we derived three phenological metrics from remotely sensed vegetation indices and associated these with climate data for the period of 1982 to 2011. The results suggested that the start of the growing season advanced by 0.10 days yr-1, the end was delayed by 0.11 days yr-1, and the length of the growing season expanded by 6.3 days during the period from 1982 to 2011. The delayed end and extended length of the growing season were observed consistently in grassland, forest, and shrubland, while the earlier start was only observed in grassland. Partial correlation analysis between the phenological events and the climate variables revealed that higher temperature was associated with an earlier start of the growing season, and both temperature and precipitation contributed to the later ending. Overall, our findings suggest that climate change will substantially alter the vegetation phenology in the grasslands of the Mongolian Plateau, and likely also in biomes with similar environmental conditions, such as other semi-arid steppe regions.

The Screening Test for Emotional Problems-Parent Report (STEP-P): Studies of Reliability and Validity

Science.gov (United States)

Erford, Bradley T.; Alsamadi, Silvana C.

2012-01-01

Score reliability and validity of parent responses concerning their 10- to 17-year-old students were analyzed using the Screening Test for Emotional Problems-Parent Report (STEP-P), which assesses a variety of emotional problems classified under the Individuals with Disabilities Education Improvement Act. Score reliability, convergent, and…

Biotic constraints on the establishment and performance of native, naturalized, and invasive plants in Pacific Northwest (USA steppe and forest

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Brian M. Connolly

2017-02-01

Full Text Available Factors that cause differential establishment among naturalized, invasive, and native species are inadequately documented, much less often quantified among different communities. We evaluated the effects of seed addition and disturbance (i.e., understory canopy removal on the establishment and seedling biomass among two naturalized, two invasive, and two native species (1 forb, 1 grass in each group within steppe and low elevation forest communities in eastern Washington, USA. Establishment within each plant immigrant class was enhanced by seed addition: naturalized species showed the greatest difference in establishment between seed addition and no seed addition plots, native and invasive species establishment also increased following seed addition but not to the same magnitude as naturalized species. Within seed addition plots, understory canopy disturbance resulted in significant increases in plant establishment (regardless of plant immigration class relative to undisturbed plots and the magnitude of this effect was comparable between steppe and adjacent forest. However, regardless of disturbance treatment fewer invasive plants established in the forest than in the steppe, whereas native and naturalized plant establishment did not differ between the habitats. Individual biomass of naturalized species were consistently greater in disturbed (canopy removed versus undisturbed control plots and naturalized species were also larger in the steppe than in the forest at the time of harvest. Similar trends in plant size were observed for the native and invasive species, but the differences in biomass for these two immigration classes between disturbance treatments and between habitats were not significant. We found that strong limitations of non-native species is correlated with intact canopy cover within the forest understory, likely driven by the direct or indirect consequences of low light transmittance through the arboreal and understory canopy

Using resilience and resistance concepts to manage threats to sagebrush ecosystems, Gunnison sage-grouse, and Greater sage-grouse in their eastern range: A strategic multi-scale approach

Science.gov (United States)

Chambers, Jeanne C.; Beck, Jeffrey L.; Campbell, Steve; Carlson, John; Christiansen, Thomas J.; Clause, Karen J.; Dinkins, Jonathan B.; Doherty, Kevin E.; Griffin, Kathleen A.; Havlina, Douglas W.; Mayer, Kenneth F.; Hennig, Jacob D.; Kurth, Laurie L.; Maestas, Jeremy D.; Manning, Mary E.; Mealor, Brian A.; McCarthy, Clinton; Perea, Marco A.; Pyke, David A.

2016-01-01

This report provides a strategic approach developed by a Western Association of Fish and Wildlife Agencies interagency working group for conservation of sagebrush ecosystems, Greater sage-grouse, and Gunnison sage-grouse. It uses information on (1) factors that influence sagebrush ecosystem resilience to disturbance and resistance to nonnative invasive annual grasses and (2) distribution and relative abundance of sage-grouse populations to address persistent ecosystem threats, such as invasive annual grasses and wildfire, and land use and development threats, such as oil and gas development and cropland conversion, to develop effective management strategies. A sage-grouse habitat matrix links relative resilience and resistance of sagebrush ecosystems with modeled sage-grouse breeding habitat probabilities to help decisionmakers assess risks and determine appropriate management strategies at both landscape and site scales. Areas for targeted management are assessed by overlaying matrix components with Greater sage-grouse Priority Areas for Conservation and Gunnison sage-grouse critical habitat and linkages, breeding bird concentration areas, and specific habitat threats. Decision tools are discussed for determining the suitability of target areas for management and the most appropriate management actions. A similar approach was developed for the Great Basin that was incorporated into the Federal land use plan amendments and served as the basis of a Bureau of Land Management Fire and Invasives Assessment Tool, which was used to prioritize sage-grouse habitat for targeted management activities.

Community structure affects annual grass weed invasion during restoration of a shrub-steppe ecosystem

Science.gov (United States)

Phil S. Allen; Susan E. Meyer

2014-01-01

Ecological restoration of shrub-steppe communities in the western United States is often hampered by invasion of exotic annual grasses during the process. An important question is how to create restored communities that can better resist reinvasion by these weeds. One hypothesis is that communities comprised of species that are functionally similar to the invader will...

History of formation of forests in the plain part of Ukraine in the Holocene

International Nuclear Information System (INIS)

Bezusko, L.G.; Mosyakin, S.L.; Tsymbalyuk, Z.M.; Bezusko, A.G.

2005-01-01

Full text: The authors analyzed and generalized the results of palynological and radiocarbon-dating studies of Holocene deposits of the forest, forest-steppe and steppe zones of Ukraine. Based on the obtained data, we reconstructed the pattern of main changes of vegetation and climate starting from 10,300 years BP. We consider changes in forest vegetation of the studied area in the Early (PB-1, PB-2, BO-1, BO-2, BO-3), Middle (AT-1, AT-2, AT-3, SB-1, SB-2, SB-3) and Late Holocene. For most important forest-forming trees (species of Pinus, Betula, Alnus, Quercus, Tilia, Carpinus, Fagus etc.), the main periods of their maximum participation in Ukrainian forest vegetation were identified. Broadleaf forests and mixed forests with participation of broadleaf trees were most widespread in Ukraine 4,500-6,200 years BP. During the second phase of the Atlantic time of the Holocene the northern border of the steppe zone in Ukraine was stable. Expansion of forest communities in the steppe zone progressed through gradual increase of forest areas that originally occurred in flood plains and ravines. (author)

The First Record of Case of the Imperial Eagle and the Steppe Eagle Successful Breeding in the Mixed Pair in Western Kazakhstan and Records of Probable Hybrids of These Species in Russia and Kazakhstan

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Igor V. Karyakin

2016-04-01

Full Text Available Facts mentioned in paper give evidence of the possibility of forming the mixed pairs between Steppe and Imperial Eagles, breeding success and fertility of hybrids. All the observed mixed pairs were found in the contact zone of the two species on the periphery of the Steppe Eagle breeding range under conditions of either decrease in numbers of one species (Steppe Eagle and the growth of another (in Western Kazakhstan, or decline in numbers of both species and the lack of birds of their own species (in Dauria. Considering the fact that the number of Steppe Eagles continues to decline, the hybridization process may amplify and this phenomenon requires a more thorough examination.

Identifying treatment effect heterogeneity in clinical trials using subpopulations of events: STEPP.

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Lazar, Ann A; Bonetti, Marco; Cole, Bernard F; Yip, Wai-Ki; Gelber, Richard D

2016-04-01

Investigators conducting randomized clinical trials often explore treatment effect heterogeneity to assess whether treatment efficacy varies according to patient characteristics. Identifying heterogeneity is central to making informed personalized healthcare decisions. Treatment effect heterogeneity can be investigated using subpopulation treatment effect pattern plot (STEPP), a non-parametric graphical approach that constructs overlapping patient subpopulations with varying values of a characteristic. Procedures for statistical testing using subpopulation treatment effect pattern plot when the endpoint of interest is survival remain an area of active investigation. A STEPP analysis was used to explore patterns of absolute and relative treatment effects for varying levels of a breast cancer biomarker, Ki-67, in the phase III Breast International Group 1-98 randomized clinical trial, comparing letrozole to tamoxifen as adjuvant therapy for postmenopausal women with hormone receptor-positive breast cancer. Absolute treatment effects were measured by differences in 4-year cumulative incidence of breast cancer recurrence, while relative effects were measured by the subdistribution hazard ratio in the presence of competing risks using O-E (observed-minus-expected) methodology, an intuitive non-parametric method. While estimation of hazard ratio values based on O-E methodology has been shown, a similar development for the subdistribution hazard ratio has not. Furthermore, we observed that the subpopulation treatment effect pattern plot analysis may not produce results, even with 100 patients within each subpopulation. After further investigation through simulation studies, we observed inflation of the type I error rate of the traditional test statistic and sometimes singular variance-covariance matrix estimates that may lead to results not being produced. This is due to the lack of sufficient number of events within the subpopulations, which we refer to as instability of

Pine Plantations and Invasion Alter Fuel Structure and Potential Fire Behavior in a Patagonian Forest-Steppe Ecotone

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Juan Paritsis

2018-03-01

Full Text Available Planted and invading non-native plant species can alter fire regimes through changes in fuel loads and in the structure and continuity of fuels, potentially modifying the flammability of native plant communities. Such changes are not easily predicted and deserve system-specific studies. In several regions of the southern hemisphere, exotic pines have been extensively planted in native treeless areas for forestry purposes and have subsequently invaded the native environments. However, studies evaluating alterations in flammability caused by pines in Patagonia are scarce. In the forest-steppe ecotone of northwestern Patagonia, we evaluated fine fuels structure and simulated fire behavior in the native shrubby steppe, pine plantations, pine invasions, and mechanically removed invasions to establish the relative ecological vulnerability of these forestry and invasion scenarios to fire. We found that pine plantations and their subsequent invasion in the Patagonian shrubby steppe produced sharp changes in fine fuel amount and its vertical and horizontal continuity. These changes in fuel properties have the potential to affect fire behavior, increasing fire intensity by almost 30 times. Pruning of basal branches in plantations may substantially reduce fire hazard by lowering the probability of fire crowning, and mechanical removal of invasion seems effective in restoring original fuel structure in the native community. The current expansion of pine plantations and subsequent invasions acting synergistically with climate warming and increased human ignitions warrant a highly vulnerable landscape in the near future for northwestern Patagonia if no management actions are undertaken.

The first horse herders and the impact of early Bronze Age steppe expansions into Asia

DEFF Research Database (Denmark)

Damgaard, Peter de Barros; Martiniano, Rui; Kamm, Jack

2018-01-01

The Eurasian steppes reach from the Ukraine in Europe to Mongolia and China. Over the past 5000 years, these flat grasslands were thought to be the route for the ebb and flow of migrant humans, their horses, and their languages. de Barros Damgaard et al. probed whole-genome sequences from the rem...

Late quaternary environmental changes in the upper Las Vegas valley, Nevada

Science.gov (United States)

Quade, Jay

1986-11-01

Five stratigraphic units and five soils of late Pleistocene to Holocene age crop out in dissected badlands on Corn Creek Flat, 30 km northwest of Las Vegas, Nevada, and at Tule Springs, nearer to Las Vegas. The record is dominantly fluvial but contains evidence of several moister, marsh-forming periods: the oldest (Unit B) dates perhaps to the middle Wisconsin, and the more widespread Unit D falls between 30,000 and 15,000 yr B.P. Unit D therefore correlates with pluvial maximum lacustrine deposits elsewhere in the Great Basin. Standing water was not of sufficient depth or extent during either period to form lake strandlines. Between 14,000 and 7200 yr B.P. (Unit E), standing surface water gradually decreased, a trend also apparent in Great Basin pluvial lake chronologies during the same period. Groundwater carbonate cementation and burrowing by cicadas (Cicadae) accompany the moist-phase units. After 7200 yr B.P., increased wind action, decreased biotic activity, and at least 25 m of water-table lowering accompanied widespread erosion of older fine-grained deposits. Based on pack-rat midden and pollen evidence, this coincides with major vegetation changes in the valley, from sagebrush-dominated steppe to lower Mohave desertscrub.

Reconstruction of the vegetation distribution of different topographic units of the Chinese Loess Plateau during the Holocene

Science.gov (United States)

Sun, Aizhi; Guo, Zhengtang; Wu, Haibin; Li, Qin; Yu, Yanyan; Luo, Yunli; Jiang, Wenying; Li, Xiaoqiang

2017-10-01

Soil erosion and related ecological restoration present a tremendous challenge to the socioeconomic development of the Chinese Loess Plateau (CLP). Although the Chinese government has addressed the problem of soil erosion via an afforestation programme, there have been several negative outcomes. One of the reasons for this is our incomplete understanding of the past natural vegetation distribution in the various topographic units of the CLP under different climate scenarios. Consequently, we used fossil pollen data from 41 sites from different topographic units, together with the biomization method, to reconstruct the Holocene vegetation distribution of the CLP. The results demonstrate significant differences in vegetation types between different topographic units: forest was distributed in mountainous areas, steppe was dominant in Yuan areas, and desert vegetation was distributed in the transition zone between loess and desert. The vegetation in the gully areas exhibited significant spatial differences during the mid-Holocene. In addition, the vegetation on the various topographic units was well-developed during the interval from 9 to 4 ka B.P., when regional moisture levels reached a maximum. This suggests that the East Asian Summer Monsoon was one of the main factors controlling the evolution of vegetation patterns during the Holocene. In addition, our results confirm that both topography and human activity were fundamental factors determining the vegetation distribution of the region. Against a background of ongoing global warming, we advocate a program of vegetation restoration including planting trees and shrubs in the mountainous areas, and promoting the growth of grasses in the Yuan areas and in the transitional zone between loess and desert. In the gully areas, the planting of trees and shrubs is appropriate for reducing soil erosion caused by human activities.

Response of alpine vegetation growth dynamics to snow cover phenology on the Tibetan Plateau

Science.gov (United States)

Wang, X.; Wu, C.

2017-12-01

Alpine vegetation plays a crucial role in global energy cycles with snow cover, an essential component of alpine land cover showing high sensitivity to climate change. The Tibetan Plateau (TP) has a typical alpine vegetation ecosystem and is rich of snow resources. With global warming, the snow of the TP has undergone significant changes that will inevitably affect the growth of alpine vegetation, but observed evidence of such interaction is limited. In particular, a comprehensive understanding of the responses of alpine vegetation growth to snow cover variability is still not well characterized on TP region. To investigate this, we calculated three indicators, the start (SOS) and length (LOS) of growing season, and the maximum of normalized difference vegetation index (NDVImax) as proxies of vegetation growth dynamics from the Moderate Resolution Imaging Spectroradiometer (MODIS) data for 2000-2015. Snow cover duration (SCD) and melt (SCM) dates were also extracted during the same time frame from the combination of MODIS and the Interactive Multi-sensor Snow and Ice Mapping System (IMS) data. We found that the snow cover phenology had a strong control on alpine vegetation growth dynamics. Furthermore, the responses of SOS, LOS and NDVImax to snow cover phenology varied among plant functional types, eco-geographical zones, and temperature and precipitation gradients. The alpine steppes showed a much stronger negative correlation between SOS and SCD, and also a more evidently positive relationship between LOS and SCD than other types, indicating a longer SCD would lead to an earlier SOS and longer LOS. Most areas showed positive correlation between SOS and SCM, while a contrary response was also found in the warm but drier areas. Both SCD and SCM showed positive correlations with NDVImax, but the relationship became weaker with the increase of precipitation. Our findings provided strong evidences between vegetation growth and snow cover phenology, and changes in

Ring Recoveries from Steppe Eagles and Eastern Imperial Eagles from the Russian and Kazakhstan Breeding Populations and a Review of Major Threats to Eagles in Iraq

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Omar F. Al-Sheikhly

2018-03-01

Full Text Available The article summarizes ring recoveries from 2 Steppe Eagles (Aquila nipalensis and 2 Eastern Imperial Eagles (Aquila heliaca from Iraq that were ringed in Russia and Kazakhstan, as well as ring recoveries from 2 Steppe Eagles and 3 Eastern Imperial Eagles from the border regions of Iraq (Iran, Kuwait and Saudi Arabia that were ringed in Russia. Threats for eagles in Iraq are discussed in this article.

Phase 1 summaries of radionuclide concentration data for vegetation, river water, drinking water, and fish

International Nuclear Information System (INIS)

Denham, D.H.; Dirkes, R.L.; Hanf, R.W.; Poston, T.M.; Thiede, M.E.; Woodruff, R.K.

1993-06-01

The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at the Hanford Site since 1944. As part of the HEDR Project, the Environmental Monitoring Data Task (Task 05) staff assemble, evaluate, and summarize key historical measurements of radionuclide concentrations in the environment as a result of Hanford operations. The scope of work performed during Phase I included initiating the search, recovery, and inventory of environmental reports. Summaries of the environmental monitoring data that were recovered and evaluated are presented for specific periods of interest. These periods include vegetation monitoring data (primarily sagebrush) for the years 1945 through 1947, Columbia River water and drinking water monitoring data for the years 1963 through 1966, and fish monitoring data for the years 1964 through 1966. Concern was limited to those radionuclides identified as the most likely major contributors to the dose potentially received by the public during the times of interest: phosphorous-32, copper-64, zinc-65, arsenic-76, and neptunium-239 in Columbia River fish and drinking water taken from the river, and iodine-131 in vegetation. This report documents the achievement of the Phase I objectives of the Environmental Monitoring Data Task

Last Glacial vegetation and climate change in the southern Levant

Science.gov (United States)

Miebach, Andrea; Chen, Chunzhu; Litt, Thomas

2015-04-01

Reconstructing past climatic and environmental conditions is a key task for understanding the history of modern mankind. The interaction between environmental change and migration processes of the modern Homo sapiens from its source area in Africa into Europe is still poorly understood. The principal corridor of the first human dispersal into Europe and also later migration dynamics crossed the Middle East. Therefore, the southern Levant is a key area to investigate the paleoenvironment during times of human migration. In this sense, the Last Glacial (MIS 4-2) is particularly interesting to investigate for two reasons. Firstly, secondary expansions of the modern Homo sapiens are expected to occur during this period. Secondly, there are ongoing discussions on the environmental conditions causing the prominent lake level high stand of Lake Lisan, the precursor of the Dead Sea. This high stand even culminated in the merging of Lake Lisan and Lake Kinneret (Sea of Galilee). To provide an independent proxy for paleoenvironmental reconstructions in the southern Levant during the Last Glacial, we investigated pollen assemblages of the Dead Sea/Lake Lisan and Lake Kinneret. Located at the Dead Sea Transform, the freshwater Lake Kinneret is nowadays connected via the Jordan with the hypersaline Dead Sea, which occupies Earth's lowest elevation on land. The southern Levant is a transition area of three different vegetation types. Therefore, also small changes in the climate conditions effect the vegetation and can be registered in the pollen assemblage. In contrast to the Holocene, our preliminary results suggest another vegetation pattern during the Last Glacial. The vegetation belt of the fragile Mediterranean biome did no longer exist in the vicinity of Lake Kinneret. Moreover, the vegetation was rather similar in the whole study area. A steppe vegetation with dwarf shrubs, herbs, and grasses predominated. Thermophilous elements like oaks occurred in limited amounts. The

Ecological restoration and recovery in the wind-blown sand hazard areas of northern China: relationship between soil water and carrying capacity for vegetation in the Tengger Desert.

Science.gov (United States)

Li, XingRong; Zhang, ZhiShan; Tan, HuiJuan; Gao, YanHong; Liu, LiChao; Wang, XingPing

2014-05-01

The main prevention and control area for wind-blown sand hazards in northern China is about 320000 km(2) in size and includes sandlands to the east of the Helan Mountain and sandy deserts and desert-steppe transitional regions to the west of the Helan Mountain. Vegetation recovery and restoration is an important and effective approach for constraining wind-blown sand hazards in these areas. After more than 50 years of long-term ecological studies in the Shapotou region of the Tengger Desert, we found that revegetation changed the hydrological processes of the original sand dune system through the utilization and space-time redistribution of soil water. The spatiotemporal dynamics of soil water was significantly related to the dynamics of the replanted vegetation for a given regional precipitation condition. The long-term changes in hydrological processes in desert areas also drive replanted vegetation succession. The soil water carrying capacity of vegetation and the model for sand fixation by revegetation in aeolian desert areas where precipitation levels are less than 200 mm are also discussed.

Quantitative assessment of pedodiversity and soil erosion within a karst sinkhole in the dry steppe subzone

Science.gov (United States)

Smirnova, M. A.; Gennadiev, A. N.

2017-08-01

A detailed study of the soil cover of a sinkhole (300 m2) in the dry steppe landscape of the Bogdinsk-Baskunchak Natural Reserve in Astrakhan oblast has been performed, and the factors of its differentiation have been analyzed. The indices of pedodiversity have been calculated and compared for karst sinkholes in the dry steppe and northern taiga landscapes. Quantitative parameters of the lateral migration of solid soil substances on the slopes of the sinkhole have been determined. The rate of soil erosion decreases from the slope of southern aspect to the slopes of western, northern, and eastern aspects. On the average, it is estimated at 0.4 mm/yr. The average rate of accumulation of solid substances on the lower parts of the slopes and in the bottom of the sinkhole reaches 0.74 mm/yr. A comparative analysis of the soil properties attests to their dependence on the particular position of a given soil within the sinkhole. Downward the slopes of the sinkhole, full-profile brown arid soils (Cambic Calcisols) are replaced by sierozem-like soils (Haplic Calcisols), light-humus poorly developed soils (Luvisols), lithozems (Leptosols), and stratified soils (stratozems, or Colluvic Regosols). The soils within the upper ring-shape soil microzone are more diverse and contrasting with respect to their morphological, physical, chemical, and physicochemical properties. The degree of soil contrasts decreases down the slopes of the sinkhole towards its bottom. The studied sinkhole is characterized by considerable pedodiversity. Quantitative parameters of pedodiversity for the sinkhole in the dry steppe zone are higher than those form the sinkholes in the northern taiga zone.

Genotype, soil type, and locale effects on reciprocal transplant vigor, endophyte growth, and microbial functional diversity of a narrow sagebrush hybrid zone in Salt Creek Canyon, Utah

Science.gov (United States)

Miglia, K.J.; McArthur, E.D.; Redman, R.S.; Rodriguez, R.J.; Zak, J.C.; Freeman, D.C.

2007-01-01

When addressing the nature of ecological adaptation and environmental factors limiting population ranges and contributing to speciation, it is important to consider not only the plant's genotype and its response to the environment, but also any close interactions that it has with other organisms, specifically, symbiotic microorganisms. To investigate this, soils and seedlings were reciprocally transplanted into common gardens of the big sagebrush hybrid zone in Salt Creek Canyon, Utah, to determine location and edaphic effects on the fitness of parental and hybrid plants. Endophytic symbionts and functional microbial diversity of indigenous and transplanted soils and sagebrush plants were also examined. Strong selection occurred against the parental genotypes in the middle hybrid zone garden in middle hybrid zone soil; F1 hybrids had the highest fitness under these conditions. Neither of the parental genotypes had superior fitness in their indigenous soils and habitats; rather F1 hybrids with the nonindigenous maternal parent were superiorly fit. Significant garden-by-soil type interactions indicate adaptation of both plant and soil microorganisms to their indigenous soils and habitats, most notably in the middle hybrid zone garden in middle hybrid zone soil. Contrasting performances of F1 hybrids suggest asymmetrical gene flow with mountain, rather than basin, big sagebrush acting as the maternal parent. We showed that the microbial community impacted the performance of parental and hybrid plants in different soils, likely limiting the ranges of the different genotypes.

The phylogeographical history of the Iberian steppe plant Ferula loscosii (Apiaceae): a test of the abundant-centre hypothesis.

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Pérez-Collazos, E; Sanchez-Gómez, P; Jiménez, F; Catalán, P

2009-03-01

The geology and climate of the western Mediterranean area were strongly modified during the Late Tertiary and the Quaternary. These geological and climatic events are thought to have induced changes in the population histories of plants in the Iberian Peninsula. However, fine-scale genetic spatial architecture across western Mediterranean steppe plant refugia has rarely been investigated. A population genetic analysis of amplified fragment length polymorphism variation was conducted on present-day, relict populations of Ferula loscosii (Apiaceae). This species exhibits high individual/population numbers in the middle Ebro river valley and, according to the hypothesis of an abundant-centre distribution, these northern populations might represent a long-standing/ancestral distribution centre. However, our results suggest that the decimated southern and central Iberian populations are more variable and structured than the northeastern ones, representing the likely vestiges of an ancestral distribution centre of the species. Phylogeographical analysis suggests that F. loscosii likely originated in southern Spain and then migrated towards the central and northeastern ranges, further supporting a Late Miocene southern-bound Mediterranean migratory way for its oriental steppe ancestors. In addition, different glacial-induced conditions affected the southern and northern steppe Iberian refugia during the Quaternary. The contrasting genetic homogeneity of the Ebro valley range populations compared to the southern Iberian ones possibly reflects more severe bottlenecks and subsequent genetic drift experienced by populations of the northern Iberia refugium during the Pleistocene, followed by successful postglacial expansion from only a few founder plants.

Mid-Holocene bottleneck for central European dry grasslands: Did steppe survive the forest optimum in northern Bohemia, Czech Republic?

Czech Academy of Sciences Publication Activity Database

Pokorný, P.; Chytrý, M.; Juřičková, L.; Sádlo, Jiří; Novák, J.; Ložek, V.

2015-01-01

Roč. 25, č. 4 (2015), s. 716-726 ISSN 0959-6836 Institutional support: RVO:67985939 Keywords : MId-Holocene * forest-steppe * pollen analysis Subject RIV: EF - Botanics Impact factor: 2.135, year: 2015

Changes in vegetation phenology on the Mongolian Plateau and their climatic determinants.

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Lijuan Miao

Full Text Available Climate change affects the timing of phenological events, such as the start, end, and length of the growing season of vegetation. A better understanding of how the phenology responded to climatic determinants is important in order to better anticipate future climate-ecosystem interactions. We examined the changes of three phenological events for the Mongolian Plateau and their climatic determinants. To do so, we derived three phenological metrics from remotely sensed vegetation indices and associated these with climate data for the period of 1982 to 2011. The results suggested that the start of the growing season advanced by 0.10 days yr-1, the end was delayed by 0.11 days yr-1, and the length of the growing season expanded by 6.3 days during the period from 1982 to 2011. The delayed end and extended length of the growing season were observed consistently in grassland, forest, and shrubland, while the earlier start was only observed in grassland. Partial correlation analysis between the phenological events and the climate variables revealed that higher temperature was associated with an earlier start of the growing season, and both temperature and precipitation contributed to the later ending. Overall, our findings suggest that climate change will substantially alter the vegetation phenology in the grasslands of the Mongolian Plateau, and likely also in biomes with similar environmental conditions, such as other semi-arid steppe regions.

Laboratory characterization of PM emissions from combustion of wildland biomass fuels

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Seyedehsan Hosseini; Shawn Urbanski; P. Dixit; Qi Li; Ian Burling; Robert Yokelson; Timothy E. Johnson; Manish Sharivastava; Heejung Jung; David R. Weise; Wayne Miller; David Cocker

2013-01-01

Particle emissions from open burning of southwestern (SW) and southeastern (SE) U.S. fuel types during 77 controlled laboratory burns are presented. The fuels include SW vegetation types: ceanothus, chamise/scrub oak, coastal sage scrub, California sagebrush, manzanita, maritime chaparral, masticated mesquite, oak savanna, and oak woodland, as well as SE vegetation...

Grazing Effects on Water Use Efficiency on a Mongolian Desert Steppe

Science.gov (United States)

Shao, C.; Chen, J.; Li, L.; John, R.; Ouyang, Z.

2015-12-01

Ecosystem-level water use efficiency (WUE), defined as the ratio of gross primary production (GPP) to evapotranspiration (ET), was assessed by continuous and simultaneous direct eddy-covariance (EC) measurements of carbon and water fluxes on adjacent pastures of grazed (DS) and ungrazed steppes (FS) in the Mongolia Plateau for a two-year period from 2010 to 2012. We found that the WUE was well positively linear correlated (r2=0.90) with the GEP both in the DS and FS. Due to our desert steppe was very sensitive to the precipitation, WUE was co-varied with the precipitation. WUE increased with the GEP increase under good water conditions, when the GEP reached its maximal value (DS: 3 g C m-2, FS: 2 g C m-2), the WUE was suppressed and kept a stable value during the peak growing season. Both GEP and WUE was near zero when the soil moisture was lower. We also found that the WUE was negatively correlated with ET. The WUE was higher in GS than that in FS. The mean seasonal WUE was 0.93 in GS and 0.54 g C kg-1 H2O in FS, with a peak monthly WUE of 1.32 in GS and 0.73 g C kg-1 H2O in FS, respectively. The difference between GS and FS mainly caused by that the ET was changed with the GEP during the entire growing season. This suggests the importance of both plant population dynamics and water statues should be considered in WUE studies.

The Application of Soil-Agroclimatic Index for Assessing the Agronomic Potential of Arable Lands in the Forest-Steppe Zone of Russia

Science.gov (United States)

Bulgakov, D. S.; Rukhovich, D. I.; Shishkonakova, E. A.; Vil'chevskaya, E. V.

2018-04-01

An assessment of the agronomic potential of arable lands in the forest-steppe zone of Russia (by the example of separate soil-agronomic districts) on the basis of the soil-agroclimatic index developed under the supervision of I.I. Karmanov is considered. The agricultural areas (64) separated on the territory of Russia and characterizing soil-agroclimatic conditions for cultivation of major and accompanying crops are differentiated into soil-agronomic districts (SADs) with due account for the administrative division of the country. A large diversity of agroclimatic and agronomical conditions creates the prerequisites for the inclusion of administrative regions into different SADs. The SADs concept implies a detailed analysis of information on the soil properties, geomorphic conditions, and farming conditions. The agronomic potential for major crops in the key SADs in the forest-steppe zone of the East European Plain (Voronezh and Penza oblasts) is high, though it is 25-30% lower than that in the North Caucasus (for winter wheat, sugar beet, sunflower, and spring barley) and in Kaliningrad oblast (for oats). In Western Siberia (Tyumen, Omsk, and Novosibirsk oblasts) and Eastern Siberia (Krasnoyarsk region and Irkutsk oblast), the agronomic potential of spring crops (wheat, barley, and oats) is only utilized by 35-45% in comparison with their European analogues. In the Far East with its monsoon climate and soil conditions (meadow podbels, brown forest soils), the crops characteristic of the European forest-steppe (soybean, rice, sugar beet) and the Trans-Ural forest-steppe (spring wheat) are cultivated. Their biological potential is utilized by only 50-60% in comparison with the European analogues. The materials of this study give us information on the degree of correspondence between the soilagroclimatic potential of the territory and the biological potential of cultivated crops. This is important in the context of improving the natural-agricultural zoning of Russia

Consequences of pre-inoculation with native arbuscular mycorrhizae on root colonization and survival of Artemisia tridentata ssp. wyomingensis (Wyoming big sagebrush) seedlings after transplanting

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Bill Eugene Davidson

2015-01-01

Inoculation of seedlings with arbuscular mycorrhizal fungi (AMF) is a common practice aimed at improving seedling establishment. The success of this practice largely depends on the ability of the inoculum to multiply and colonize the growing root system after transplanting. These events were investigated in Artemisia tridentata ssp. wyomingensis (Wyoming big sagebrush...

Vegetation and Climate Change during the Last Deglaciation in the Great Khingan Mountain, Northeastern China.

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Wu, Jing; Liu, Qiang; Wang, Luo; Chu, Guo-qiang; Liu, Jia-qi

2016-01-01

The Great Khingan Mountain range, Northeast China, is located on the northern limit of modern East Asian Summer Monsoon (EASM) and thus highly sensitive to the extension of the EASM from glacial to interglacial modes. Here, we present a high-resolution pollen record covering the last glacial maximum and the early Holocene from a closed crater Lake Moon to reconstruct vegetation history during the glacial-interglacial transition and thus register the evolution of the EASM during the last deglaciation. The vegetation history has gone through distinct changes from subalpine meadow in the last glacial maximum to dry steppe dominated by Artemisia from 20.3 to 17.4 ka BP, subalpine meadow dominated by Cyperaceae and Artemisia between 17.4 and 14.4 ka BP, and forest steppe dominated by Betula and Artemisia after 14.4 ka BP. The pollen-based temperature index demonstrates a gradual warming trend started at around 20.3 ka BP with interruptions of several brief events. Two cold conditions occurred around at 17.2-16.6 ka BP and 12.8-11.8 ka BP, temporally correlating to the Henrich 1 and the Younger Dryas events respectively, 1and abrupt warming events occurred around at 14.4 ka BP and 11.8 ka BP, probably relevant to the beginning of the Bølling-Allerød stages and the Holocene. The pollen-based moisture proxy shows distinct drought condition during the last glacial maximum (20.3-18.0 ka BP) and the Younger Dryas. The climate history based on pollen record of Lake Moon suggests that the regional temperature variability was coherent with the classical climate in the North Atlantic, implying the dominance of the high latitude processes on the EASM evolution from the Last Glacial Maximum (LGM) to early Holocene. The local humidity variability was influenced by the EASM limitedly before the Bølling-Allerød warming, which is mainly controlled by the summer rainfall due to the EASM front covering the Northeast China after that.

Vegetation and Climate Change during the Last Deglaciation in the Great Khingan Mountain, Northeastern China.

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Jing Wu

Full Text Available The Great Khingan Mountain range, Northeast China, is located on the northern limit of modern East Asian Summer Monsoon (EASM and thus highly sensitive to the extension of the EASM from glacial to interglacial modes. Here, we present a high-resolution pollen record covering the last glacial maximum and the early Holocene from a closed crater Lake Moon to reconstruct vegetation history during the glacial-interglacial transition and thus register the evolution of the EASM during the last deglaciation. The vegetation history has gone through distinct changes from subalpine meadow in the last glacial maximum to dry steppe dominated by Artemisia from 20.3 to 17.4 ka BP, subalpine meadow dominated by Cyperaceae and Artemisia between 17.4 and 14.4 ka BP, and forest steppe dominated by Betula and Artemisia after 14.4 ka BP. The pollen-based temperature index demonstrates a gradual warming trend started at around 20.3 ka BP with interruptions of several brief events. Two cold conditions occurred around at 17.2-16.6 ka BP and 12.8-11.8 ka BP, temporally correlating to the Henrich 1 and the Younger Dryas events respectively, 1and abrupt warming events occurred around at 14.4 ka BP and 11.8 ka BP, probably relevant to the beginning of the Bølling-Allerød stages and the Holocene. The pollen-based moisture proxy shows distinct drought condition during the last glacial maximum (20.3-18.0 ka BP and the Younger Dryas. The climate history based on pollen record of Lake Moon suggests that the regional temperature variability was coherent with the classical climate in the North Atlantic, implying the dominance of the high latitude processes on the EASM evolution from the Last Glacial Maximum (LGM to early Holocene. The local humidity variability was influenced by the EASM limitedly before the Bølling-Allerød warming, which is mainly controlled by the summer rainfall due to the EASM front covering the Northeast China after that.

[Soil respiration dynamics and its controlling factors of typical vegetation communities on meadow steppes in the western Songnen Plain].

Science.gov (United States)

Wang, Ming; Liu, Xing-Tu; Li, Xiu-Jun; Zhang, Ji-Tao; Wang, Guo-Dong; Lu, Xin-Rui; Li, Xiao-Yu

2014-01-01

In order to accurately explore the soil respiration dynamics and its controlling factors of typical vegetation types in the western Songnen Plain, soil respiration rates of Chloris virgata, Puccinellia distans, Phragmites australis and Leymus chinensis communities were measured. The results showed that the diurnal curves of soil respiration rates of the four vegetation communities had simple peak values, which appeared at 11:00-15:00, and the valley values occurred at 21:00-1:00 or 3:00-5:00. The seasonal dynamic patterns of their soil respiration rates were similar, with the maximum (3.21-4.84 micromol CO2 x m(-2) x s(-1)) occurring in July and August and the minimum (0.46-1.51 micromol CO2 x m(-2) x s(-1)) in October. The soil respiration rates of the four vegetation communities had significant exponential correlations with ambient air temperature and soil temperature. Soil moisture, however, only played an important role in affecting the soil respiration rate of C. virgata community while air humidity near the soil surface was significantly correlated with the soil respiration rates of P. australis and L. chinensis communities. The soil salt contents seriously constrained the CO2 dioxide emission, and the soil pH, electrical conductivity (EC), exchangeable sodium percentage (ESP) could explain 87%-91% spatial variations of the soil respiration rate.

The Fifth International Conference “Dialogue of Urban and Steppe Cultures on the Eurasian Space”, ad memoriam G.A. Fyodorov-Davydov

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Zeleneev Yuriy A.

2012-03-01

Full Text Available The Fifth International Conference "Dialogue of Urban and Steppe Cultures on the Eurasian Space", dedicated to the memory of G. A. Fyodorov-Davydov, was held in the village of Selitrennoye, Astrakhan oblast, in October 2011. For the 10 years of holding these conferences, a range of constantly debated issues has formed. To these refer problems as: the steppes of Eurasia from the Early Iron Age through to the Middle Ages; relations of the Golden Horde with the outside world; medieval numismatics; natural science and combined statistics methods in archaeology. The contributions were mainly centered on these issues. The materials of the conference were published as a collection of articles.

Seasonal Distribution and Diversity of Ground Arthropods in Microhabitats Following a Shrub Plantation Age Sequence in Desertified Steppe

Science.gov (United States)

Liu, Rentao; Zhu, Fan; Song, Naiping; Yang, Xinguo; Chai, Yongqing

2013-01-01

In desertified regions, shrub-dominated patches are important microhabitats for ground arthropod assemblages. As shrub age increases, soil, vegetation and microbiological properties can change remarkably and spontaneously across seasons. However, relatively few studies have analyzed how ground arthropods respond to the microhabitats created by shrubs of different plantation ages across seasons. Using 6, 15, 24 and 36 year-old plantations of re-vegetated shrubs (Caragana koushinskii) in the desert steppe of northwestern China as a model system, we sampled ground arthropod communities using a pitfall trapping method in the microhabitats under shrubs and in the open areas between shrubs, during the spring, summer and autumn. The total ground arthropod assemblage was dominated by Carabidae, Melolonthidae, Curculionidae, Tenebrionidae and Formicidae that were affected by plantation age, seasonal changes, or the interaction between these factors, with the later two groups also influenced by microhabitat. Overall, a facilitative effect was observed, with more arthropods and a greater diversity found under shrubs as compared to open areas, but this was markedly affected by seasonal changes. There was a high degree of similarity in arthropod assemblages and diversity between microhabitats in summer and autumn. Shrub plantation age significantly influenced the distribution of the most abundant groups, and also the diversity indices of the ground arthropods. However, there was not an overall positive relationship between shrub age and arthropod abundance, richness or diversity index. The influence of plantation age on arthropod communities was also affected by seasonal changes. From spring through summer to autumn, community indices of ground arthropods tended to decline, and a high degree of similarity in these indices (with fluctuation) was observed among different ages of shrub plantation in autumn. Altogether the recovery of arthropod communities was markedly affected by

The infield varietu of available forms in the forest-steppe of western part Central Chernozemic region

Science.gov (United States)

Belik, Anton; Devyatova, Tatiana; Bozhko, Svetlana; Gorbunova, Yulia

2016-04-01

The infield varietu of available forms in the forest-steppe of western part Central Chernozemic region The Central Chernozemic region of Russia has been a region with a strong agricultural industry and determines the food security of the state by most part. The soil cover of the region is represented mainly by chernozems and is favorable for the cultivation of major crops and produce high crop yields. However, the high development of agriculture in the territory of Central Chernozemic region are led to the development of agrogenic degradation processes which impacts on the growth of the soil cover complexity and contrast, and as a consequence a significant infield variety of soil fertility and yields of major crops. In this regard, very promising direction in CChR is the development and practical application technologies of precision agriculture, which implies the spatial variety of soil fertility analysis within specific fields and work areas, especially the content of available forms of nutrients. The aim of our research was a study of the agro-ecological characteristics of the spatial variety of the content by available forms to plants of major nutrients in representative areas of sloping agricultural landscapes with forest-steppe chernozems in the western part of Central Chernozemic region of Russia. The research of infield variety by content of available forms of major nutrients are carried in the fields of Russian Research Institute of Agriculture and Protect the Soil from Erosion experimental and industrial farm in Medvensky district of Kursk region. The area characterized by a complex organization of relief. The soil cover is represented by full-profile typical (conventional and carbonate), leached chernozems. The growth of contrast of the soil cover are largely determined by the appearance of eroded soils of these analogues, as well as zoogenic dug and accumulative soils All of the studied areas with the forest-steppe chernozems were characterized by

Response of bird community structure to habitat management in piñon-juniper woodland-sagebrush ecotones

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Knick, Steven T.; Hanser, Steven E.; Grace, James B.; Hollenbeck, Jeff P.; Leu, Matthias

2017-01-01

Piñon (Pinus spp.) and juniper (Juniperus spp.) woodlands have been expanding their range across the intermountain western United States into landscapes dominated by sagebrush (Artemisia spp.) shrublands. Management actions using prescribed fire and mechanical cutting to reduce woodland cover and control expansion provided opportunities to understand how environmental structure and changes due to these treatments influence bird communities in piñon-juniper systems. We surveyed 43 species of birds and measured vegetation for 1–3 years prior to treatment and 6–7 years post-treatment at 13 locations across Oregon, California, Idaho, Nevada, and Utah. We used structural equation modeling to develop and statistically test our conceptual model that the current bird assembly at a site is structured primarily by the previous bird community with additional drivers from current and surrounding habitat conditions as well as external regional bird dynamics. Treatment reduced woodland cover by >5% at 80 of 378 survey sites. However, habitat change achieved by treatment was highly variable because actual disturbance differed widely in extent and intensity. Biological inertia in the bird community was the strongest single driver; 72% of the variation in the bird assemblage was explained by the community that existed seven years earlier. Greater net reduction in woodlands resulted in slight shifts in the bird community to one having ecotone or shrubland affinities. However, the overall influence of woodland changes from treatment were relatively small and were buffered by other extrinsic factors. Regional bird dynamics did not significantly influence the structure of local bird communities at our sites. Our results suggest that bird communities in piñon-juniper woodlands can be highly stable when management treatments are conducted in areas with more advanced woodland development and at the level of disturbance measured in our study.

[Effects of alien species Robinia pseudoacacia on plant community functional structure in hilly-gully region of Loess Plateau, China.

Science.gov (United States)

Zhu, Duo Ju; Wen, Zhong Ming; Zhang, Jing; Tao, Yu; Zeng, Hong Wen; Tang, Yang

2018-02-01

To investigate the effects of the introduction of Robinia pseudoacacia on the functional structure of plant communities, we selected paired-plots of R. pseudoacacia communities and native plant communities across different vegetation zones, i.e., steppe zone, forest-steppe zone, forest zone in hilly-gully region of Loess Plateau, China. We measured several functional characteristics and then compared the functional structures of R. pseudoacacia and native plant communities in different vegetation zones. The results showed that the variation of the functional traits across different vegetation zones were consistent in R. pseudoacacia community and native plant community, including leaf carbon concentration, leaf nitrogen concentration, leaf phosphorus concentration, specific leaf area, and leaf tissue density. The leaf carbon concentration, leaf nitrogen concentration, and specific leaf area of the R. pseudoacacia community were significantly higher than those of the native plant community. The trend of change that the functional diversity indices, i.e., FR ic , FE ve , FD iv , FD is , Rao of the R. pseudoacacia community and the native plant community with vegetation zones were different. The introduction of R. pseudoacacia enhanced the plant community functional diversity in the forest zone but reduced community functional diversity in the steppe zone.

Exploring the Role of Humans and Climate over the Balkan Landscape: 500 Years of Vegetational History of Serbia

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Kulkarni, Charuta; Peteet, Dorothy; Boger, Rebecca; Heusser, Linda

2016-01-01

We present the first, well-dated, high-resolution record of vegetation and landscape change from Serbia, which spans the past 500 years. Biological proxies (pollen, spores, and charcoal), geochemical analysis through X-ray Fluorescence (XRF), and a detailed chronology based on AMS C-14 dating from a western Serbian sinkhole core suggest complex woodland-grassland dynamics and strong erosional signals throughout the Little Ice Age (LIA). An open landscape with prominent steppe vegetation (e.g. Poaceae, Chenopodiaceae) and minor woodland exists during 1540-1720 CE (early LIA), while the late LIA (1720-1850 CE) in this record shows higher tree percentages possibly due to increased moisture availability. The post LIA Era (1850-2012 CE) brings a disturbed type of vegetation with the presence of weedy genera and an increase in regional woodland. Anthropogenic indicators for agricultural, pastoral and fire practices in the region together attest to the dominant role of humans in shaping this Balkan landscape throughout the interval. The changing nature of human interference, potentially as a response to underlying climatic transitions, is evident through large-scale soil depletion resulting from grazing and land clearance during the early LIA and stabilization of arable lands during the late and post-LIA eras.

Response of soft winter wheat (Triticum aestivum L. to longtime enforced dormancy and time of spring vegetation recommencing

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В. С. Хахула

2013-05-01

Full Text Available The article highlights the results of studying the soft winter wheat response to the duration of enforced winter dormancy and the time of vegetation recommencing, their impact on growth, development and the survival of the crops. It is found that the impact of those factors in the conditions of central Forest-Steppe of Ukraine is essential, which is to be taken into consideration when scheduling the measures of spring and summer care over the cultivated crops, in particular, where the spring extra nutrition takes place, pesticides and growth regulators are applied, the spaced planting resowing or partial resowing issues are to be settled down. The ecological effect of spring vegetation recommencing dates does not expose annually, therefore it is not always possible to predict the plant development type, but it is possible, nevertheless, to influence the processes of growth, development and survival of plants throughout spring-summer period and the development of their production capacity by means of introducing the intense technologies, optimization of mineral nutrition and the use of plant growth regulators, protection from rogues, diseases, pests.

Vegetation communities associated with the 100-Area and 200-Area facilities on the Hanford Site

International Nuclear Information System (INIS)

Stegen, J.A.

1994-01-01

The Hanford Site, Benton County, Washington, lies within the broad semi-arid shrub-steppe vegetation zone of the Columbia Basin. Thirteen different habitat types on the Hanford Site have been mapped in Habitat Types on the Hanford Site: Wildlife and Plant Species of Concern (Downs et al. 1993). In a broad sense, this classification is correct. On a smaller scale, however, finer delineations are possible. This study was conducted to determine the plant communities and estimate vegetation cover in and directly adjacent to the 100 and 200 Areas, primarily in relation to waste sites, as part of a comprehensive ecological study for the Compensation Environmental Response, Compensation, and Liability Act (CERCLA) characterization of the 100 and 200 Areas. During the summer of 1993, field surveys were conducted and a map of vegetation communities in each area, including dominant species associations, was produced. The field surveys consisted of qualitative community delineations. The community delineations described were made by field reconnaissance and are qualitative in nature. The delineations were made by visually determining the dominant plant species or vegetation types and were based on the species most apparent at the time of inspection. Additionally, 38 transects were run in these plant communities to try to obtain a more accurate representation of the community. Because habitat disturbances from construction/operations activities continue to occur in these areas, users of this information should be cautious in applying these maps without a current ground survey. This work will complement large-scale habitat maps of the Hanford Site

Vegetation communities associated with the 100-Area and 200-Area facilities on the Hanford Site

Energy Technology Data Exchange (ETDEWEB)

Stegen, J.A.

1994-01-17

The Hanford Site, Benton County, Washington, lies within the broad semi-arid shrub-steppe vegetation zone of the Columbia Basin. Thirteen different habitat types on the Hanford Site have been mapped in Habitat Types on the Hanford Site: Wildlife and Plant Species of Concern (Downs et al. 1993). In a broad sense, this classification is correct. On a smaller scale, however, finer delineations are possible. This study was conducted to determine the plant communities and estimate vegetation cover in and directly adjacent to the 100 and 200 Areas, primarily in relation to waste sites, as part of a comprehensive ecological study for the Compensation Environmental Response, Compensation, and Liability Act (CERCLA) characterization of the 100 and 200 Areas. During the summer of 1993, field surveys were conducted and a map of vegetation communities in each area, including dominant species associations, was produced. The field surveys consisted of qualitative community delineations. The community delineations described were made by field reconnaissance and are qualitative in nature. The delineations were made by visually determining the dominant plant species or vegetation types and were based on the species most apparent at the time of inspection. Additionally, 38 transects were run in these plant communities to try to obtain a more accurate representation of the community. Because habitat disturbances from construction/operations activities continue to occur in these areas, users of this information should be cautious in applying these maps without a current ground survey. This work will complement large-scale habitat maps of the Hanford Site.

Nest mortality of sagebrush songbirds due to a severe hailstorm

Science.gov (United States)

Hightower, Jessica N.; Carlisle, Jason D.; Chalfoun, Anna D.

2018-01-01

Demographic assessments of nesting birds typically focus on failures due to nest predation or brood parasitism. Extreme weather events such as hailstorms, however, can also destroy eggs and injure or kill juvenile and adult birds at the nest. We documented the effects of a severe hailstorm on 3 species of sagebrush-associated songbirds: Sage Thrasher (Oreoscoptes montanus), Brewer's Sparrow (Spizella breweri), and Vesper Sparrow (Pooecetes gramineus), nesting at eight 24 ha study plots in central Wyoming, USA. Across all plots, 17% of 128 nests failed due to the hailstorm; however, all failed nests were located at a subset of study plots (n = 3) where the hailstorm was most intense, and 45% of all nests failures on those plots were due to hail. Mortality rates varied by species, nest architecture, and nest placement. Nests with more robust architecture and those sited more deeply under the shrub canopy were more likely to survive the hailstorm, suggesting that natural history traits may modulate mortality risk due to hailstorms. While sporadic in nature, hailstorms may represent a significant source of nest failure to songbirds in certain locations, especially with increasing storm frequency and severity forecasted in some regions with ongoing climate change.

Essai sur le rôle d’une espèce végétale rustique pour un développement durable de la steppe algérienne

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Benabdeli Khéloufi

2006-07-01

Full Text Available La steppe en Algérie est un espace stratégique en matière de lutte contre la désertification, il couvre plus de 20 millions d’hectares et connaît une dégradation importante. Différents programmes de protection et de réhabilitation de cet espace ont échoué et sont souvent à l’origine de l’aggravation de cette dégradation. Une synthèse sur les causes de cet échec permettront de proposer une nouvelle approche axée sur l’introduction d’une espèce végétale très rustique et dont l’impact écologique pourrait sauver la steppe.The steppe in Algeria is a strategic space as regards to the control of desertification, it covers more than 20 million hectares and knows an important degradation. Various programmes of protection and rehabilitation concerning this space failed and are at the origin of the aggravation of this degradation. A synthesis of the causes of this failure will make it possible to propose a new approach centered on the introduction of a very rustic plant species and whose ecological impact could save the steppe.

Agrogenic degradation of soils in Krasnoyarsk forest-steppe

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Shpedt, A. A.; Trubnikov, Yu. N.; Zharinova, N. Yu.

2017-10-01

Agrogenic degradation of soils in Krasnoyarsk forest-steppe was investigated. Paleocryogenic microtopography of microlows and microhighs in this area predetermined the formation of paragenetic soil series and variegated soil cover. Specific paleogeographic conditions, thin humus horizons and soil profiles, and long-term agricultural use of the land resulted in the formation of soils unstable to degradation processes and subjected to active wind and water erosion. Intensive mechanical soil disturbances during tillage and long-term incorporation of the underlying Late Pleistocene (Sartan) calcareous silty and clay loams into the upper soil horizons during tillage adversely affected the soil properties. We determined the contents of total and labile humus and easily decomposable organic matter and evaluated the degree of soil exhaustion. It was concluded that in the case of ignorance of the norms of land use and soil conservation practices, intense soil degradation would continue leading to complete destruction of the soil cover within large areas.

Polen y vegetación en la Patagonia extraandina argentina a 45º S

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Burry, Lidia S.

2005-12-01

Full Text Available Modern pollen dispersal and deposition in relation to vegetation and environmental variables at 45° S was studied in Argentinian Patagonia east of the Andes to build a modern pollen model. This model will serve to identify modern pollen assemblages that are analog of past pollen assemblages. A west-to-east gradient of decreasing precipitation and increasing temperature determines four vegetation units: (1 grass steppe, (2 grass-bush steppe, (3 bush steppe and (4 bush-brush steppe. Pollen samples were analyzed by classification and ordination methods, and correlated to environmental variables. The steppes (a dominated by the functional type grass, (1 grass steppe, and (2 grass-bush steppe located in the more humid and cooler west end of the region were separated from the (b bush-dominated steppes (3 bush steppe and (4 bush-brush steppe occurring in the central and eastern parts of the region, where conditions are drier and warmer. Azonal communities were identified as halophytic bush steppes within different vegetation units along the west-east gradient. Environmental variables related to vegetation distribution are temperature and interannual precipitation variability associated with the precipitation gradient from the cordillera to the coast, and soil salinity in the case of azonal communities.Se investigó la relación de la dispersión-deposición del polen actual con la vegetación y con variables ambientales en la Patagonia extraandina argentina a 45° S con el fin de construir un modelo polínico actual. Este modelo servirá para identificar los conjuntos polínicos actuales que sean análogos de conjuntos polínicos fósiles. En la región hay un gradiente decreciente de precipitación y creciente de temperatura de oeste a este, que determina la existencia de diferentes unidades de vegetación: (1 estepa graminosa; (2 estepa graminosa-arbustiva; (3 estepa arbustiva y (4 estepa arbustiva-matorral. Los datos de polen de muestras de suelo

Subpopulation Treatment Effect Pattern Plot (STEPP) analysis for continuous, binary, and count outcomes.

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Yip, Wai-Ki; Bonetti, Marco; Cole, Bernard F; Barcella, William; Wang, Xin Victoria; Lazar, Ann; Gelber, Richard D

2016-08-01

For the past few decades, randomized clinical trials have provided evidence for effective treatments by comparing several competing therapies. Their successes have led to numerous new therapies to combat many diseases. However, since their conclusions are based on the entire cohort in the trial, the treatment recommendation is for everyone, and may not be the best option for an individual. Medical research is now focusing more on providing personalized care for patients, which requires investigating how patient characteristics, including novel biomarkers, modify the effect of current treatment modalities. This is known as heterogeneity of treatment effects. A better understanding of the interaction between treatment and patient-specific prognostic factors will enable practitioners to expand the availability of tailored therapies, with the ultimate goal of improving patient outcomes. The Subpopulation Treatment Effect Pattern Plot (STEPP) approach was developed to allow researchers to investigate the heterogeneity of treatment effects on survival outcomes across values of a (continuously measured) covariate, such as a biomarker measurement. Here, we extend the Subpopulation Treatment Effect Pattern Plot approach to continuous, binary, and count outcomes, which can be easily modeled using generalized linear models. With this extension of Subpopulation Treatment Effect Pattern Plot, these additional types of treatment effects within subpopulations defined with respect to a covariate of interest can be estimated, and the statistical significance of any observed heterogeneity of treatment effect can be assessed using permutation tests. The desirable feature that commonly used models are applied to well-defined patient subgroups to estimate treatment effects is retained in this extension. We describe a simulation study to confirm that the proper Type I error rate is maintained when there is no treatment heterogeneity, and a power study to show that the statistics have

Grazing moderates increases in C3 grass abundance over seven decades across a soil texture gradient in shortgrass steppe

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Questions: How does long-term grazing exclusion influence plant community composition in a semiarid grassland? Can spatial variation in the effects of grazing exclusion be explained by variation in soil texture? Location: The shortgrass steppe of northeastern Colorado, USA, located in the North Amer...

Breeding ecology of the endemic Black Lark Melanocorypha yeltoniensis on natural steppe and abandoned croplands in post-Soviet Kazakhstan

NARCIS (Netherlands)

Lameris, T.K.; Fijen, Thijs P.M.; Urazaliev, Ruslan; Pulikova, Genrietta; Donald, Paul F.; Kamp, Johannes

2016-01-01

Since the collapse of the Soviet Union in 1991, the abundance and distribution of many central Asian steppe birds have been affected by changes in agricultural land management, such as the abandonment of large areas of cropland and changing grazing patterns. However, the underlying population

Integrating spatially explicit indices of abundance and habitat quality: an applied example for greater sage-grouse management.

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Coates, Peter S; Casazza, Michael L; Ricca, Mark A; Brussee, Brianne E; Blomberg, Erik J; Gustafson, K Benjamin; Overton, Cory T; Davis, Dawn M; Niell, Lara E; Espinosa, Shawn P; Gardner, Scott C; Delehanty, David J

2016-02-01

Predictive species distributional models are a cornerstone of wildlife conservation planning. Constructing such models requires robust underpinning science that integrates formerly disparate data types to achieve effective species management.Greater sage-grouse Centrocercus urophasianus , hereafter 'sage-grouse' populations are declining throughout sagebrush-steppe ecosystems in North America, particularly within the Great Basin, which heightens the need for novel management tools that maximize the use of available information.Herein, we improve upon existing species distribution models by combining information about sage-grouse habitat quality, distribution and abundance from multiple data sources. To measure habitat, we created spatially explicit maps depicting habitat selection indices (HSI) informed by >35 500 independent telemetry locations from >1600 sage-grouse collected over 15 years across much of the Great Basin. These indices were derived from models that accounted for selection at different spatial scales and seasons. A region-wide HSI was calculated using the HSI surfaces modelled for 12 independent subregions and then demarcated into distinct habitat quality classes.We also employed a novel index to describe landscape patterns of sage-grouse abundance and space use (AUI). The AUI is a probabilistic composite of the following: (i) breeding density patterns based on the spatial configuration of breeding leks and associated trends in male attendance; and (ii) year-round patterns of space use indexed by the decreasing probability of use with increasing distance to leks. The continuous AUI surface was then reclassified into two classes representing high and low/no use and abundance. Synthesis and application s. Using the example of sage-grouse, we demonstrate how the joint application of indices of habitat selection, abundance and space use derived from multiple data sources yields a composite map that can guide effective allocation of management

Integrating spatially explicit indices of abundance and habitat quality: an applied example for greater sage-grouse management

Science.gov (United States)

Coates, Peter S.; Casazza, Michael L.; Ricca, Mark A.; Brussee, Brianne E.; Blomberg, Erik J.; Gustafson, K. Benjamin; Overton, Cory T.; Davis, Dawn M.; Niell, Lara E.; Espinosa, Shawn P.; Gardner, Scott C.; Delehanty, David J.

2016-01-01

Predictive species distributional models are a cornerstone of wildlife conservation planning. Constructing such models requires robust underpinning science that integrates formerly disparate data types to achieve effective species management. Greater sage-grouse Centrocercus urophasianus, hereafter “sage-grouse” populations are declining throughout sagebrush-steppe ecosystems in North America, particularly within the Great Basin, which heightens the need for novel management tools that maximize use of available information. Herein, we improve upon existing species distribution models by combining information about sage-grouse habitat quality, distribution, and abundance from multiple data sources. To measure habitat, we created spatially explicit maps depicting habitat selection indices (HSI) informed by > 35 500 independent telemetry locations from > 1600 sage-grouse collected over 15 years across much of the Great Basin. These indices were derived from models that accounted for selection at different spatial scales and seasons. A region-wide HSI was calculated using the HSI surfaces modelled for 12 independent subregions and then demarcated into distinct habitat quality classes. We also employed a novel index to describe landscape patterns of sage-grouse abundance and space use (AUI). The AUI is a probabilistic composite of: (i) breeding density patterns based on the spatial configuration of breeding leks and associated trends in male attendance; and (ii) year-round patterns of space use indexed by the decreasing probability of use with increasing distance to leks. The continuous AUI surface was then reclassified into two classes representing high and low/no use and abundance. Synthesis and applications. Using the example of sage-grouse, we demonstrate how the joint application of indices of habitat selection, abundance, and space use derived from multiple data sources yields a composite map that can guide effective allocation of management intensity across

The availability of mineral nitrogen in Mediterranean open steppe dominated by Stipa tenacissima L.

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Irena Novosádová

2011-01-01

Full Text Available The area of interest is located in the Sierra de los Filabres in semi-arid steppe of the province of Almeria in Spain. The amount of water in the soil is a limiting factor and its availability affects the structure and species composition of ecosystem. On the other hand, the type of vegetation affects the water loss via evapotranspiration and thus the soil microclimate. It has a great influence on the growth and activity of soil microbial communities and hence the dynamics of decomposition of organic matter and nutrient availability. The aim of this study was to assess the intensity of microbial transformations of soil organic nitrogen and describe changes in the content of nitrogen mineral forms at different depths in the semi-arid climate soil in the Mediterranean region. Availability and movement of nitrogen was monitored by capturing the mineral nitrogen into the structures of ion exchange resin applied to the soil in three different variants (control variant, a variant with the addition of cellulose, and the variant with the addition of raw silk. Ion exchange resins have been installed into soil profile in 2008, 2009, and 2010. After the in situ exposure the ion exchange resins were removed from the soil profile and the quantity of captured mineral N was determined by distillation titration method. The availability of ammonia-nitrogen was significantly affected by the addition of different substrates mainly by the additions of the raw silk, where the availability was regularly the highest. However, the availability of ammonia-nitrogen form was generally higher than the availability of nitrate form.

Noteworthy records of reptiles from natural open vegetation areas in plateau and coastal areas of the state of Santa Catarina, southern Brazil

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Ivo Rohling Ghizoni-Jr.

2009-09-01

Full Text Available The composition and geographic distribution of reptiles in Santa Catarina are little known, particularly in the open areas of its plateau (covered with ombrophylous steppe and Atlantic littoral (coastal dunes with thin, low, and predominant herbaceous vegetation known as restinga. Aiming to contribute to the knowledge of reptiles that inhabit these areas, this paper presents sixteen records of previously unknown or uncommon species in Santa Catarina: Acanthochelys spixii, Anops kingii, Cnemidophorus lacertoides, C. vacariensis, Leptotyphlops munoai, Mastigodryas b. bifossatus, Tantilla aff. melanocephala, Atractus reticulatus, Gomesophis brasiliensis, Lygophis flavifrenatus, Oxyrhopus r. rhombifer, Phalotris reticulatus, Philodryas agassizii, Xenodon dorbignyi, Micrurus altirostris and Bothrops pubescens. Aspects of the distribution and conservation of these species are discussed briefly.

Large regional-scale variation in C3/C4 distribution pattern of Inner Mongolia steppe is revealed by grazer wool carbon isotope composition

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K. Auerswald

2009-05-01

Full Text Available This work explored the spatial variation of C3/C4 distribution in the Inner Mongolia, P. R. China, steppe by geostatistical analysis of carbon isotope data of vegetation and sheep wool. Standing community biomass (n=118 and sheep wool (n=146 were sampled in a ~0.2 Mio km² area. Samples from ten consecutive years (1998–2007 were obtained. Community biomass samples represented the carbon isotopic composition of standing vegetation on about 1000 m² ("community-scale", whereas the spatio-temporal scale of wool reflected the isotope composition of the entire area grazed by the herd during a 1-yr period (~5–10 km², "farm-scale". Pair wise sampling of wool and vegetation revealed a ¹³C-enrichment of 2.7±0.7‰ (95% confidence interval in wool relative to vegetation, but this shift exhibited no apparent relationships with environmental parameters or stocking rate. The proportion of C4 plants in above-ground biomass (P_C4, % was estimated with a two-member mixing model of ¹³C discrimination by C3 and C4 vegetation (¹³Δ₃ and ¹³Δ₄, respectively, in accounting for the effects of changing ¹³C in atmospheric CO₂ on sample isotope composition, and of altitude and aridity on ¹³Δ₃. P_C4 averaged 19%, but the variation was enormous: full-scale (0% to 100% at community-scale, and 0% to 85% at farm-scale. The farm-scale variation of P_C4 exhibited a clear regional pattern over a range of ~250 km. Importantly P_C4 was significantly higher above the 22°C isotherm of the warmest month, which was obtained from annual high-resolution maps and averaged over the different sampling years. This is consistent with predictions from C3/C4 crossover temperature of quantum yield or light use efficiency in C3 and C4 plants. Still, temperature gradients accounted for only 10% of

Natural vegetation at the proposed Reference Repository Location in southeastern Washington

International Nuclear Information System (INIS)

Rickard, W.H.

1988-02-01

The dominant shrubs were sagebrush and spiny hopsage; the herbs were dominated by cheatgrass and Sandberg bluegrass. Spiny hopsage appeared to be vulnerable to burning and also to damage by off-road vehicular traffic. It appears to have little or no ability to reproduce through seedlings; once the existing plants are killed they are not likely to be replaced, even if seed-producing plants are nearby. The only pure stand of spiny hopsage known to exist on the Hanford Site is on and near study plot 2H. Sagebrush, like spiny hopsage, is killed by burning and by heavy vehicles. Sagebrush is capable of reproducing via seeds, indicating that it is an inherently aggressive species with a capacity to reestablish itself if parent plants are in the vicinity to act as seed sources. Alien, annual plants, especially cheatgrass, were a major contributor to the herbaceous canopy cover in plots 3S, 4S, and 5S. However, native perennial grasses, especially Sandberg bluegrass, were a major contributor to the canopy cover in plots 1S and 2H. These differences are probably caused by differences in soil properties (e.g., water retention capacity), rather than to historical disturbances such as livestock grazing or wildfire. Specimens of Sandwort, Arenaria franklinii, growing near the Reference Repository Location were collected for examination by taxonomists to determine if the specimens are of the variety A. f. thompsonii, a taxon currently listed as threatened in the state of Washington. 16 refs., 7 figs., 3 tabs

Systems Training for Emotional Predictability and Problem Solving (STEPPS): program efficacy and personality features as predictors of drop-out -- an Italian study.

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Alesiani, Roberta; Boccalon, Silvia; Giarolli, Laura; Blum, Nancee; Fossati, Andrea

2014-05-01

In this study we present a clinical application of the STEPPS model in an Italian sample of severely affected patients with borderline personality disorder (BPD) or personality disorder (PD) with prominent borderline features in comorbidity with a mood disorder. The aims of this work are: 1) to confirm our preliminary results in a larger sample and at a 12-month follow-up, and 2) to identify predictors of drop-out vs completion of STEPPS in order to understand which characteristics of patients make them suitable or not for this treatment. The sample is composed of 32 subjects recruited from a population of inpatients of the Mood Disorders Center, Department of Clinical Neurosciences, Hospital San Raffaele-Turro, Milan. To confirm STEPPS efficacy at 12-month follow-up, we selected the following outcome criteria: reduction in the number of hospitalizations related to self-harm acts; reduction in the number of suicidal attempts; reduction of perceived emotional intensity levels; changes in cognitive filter scores; changes in the scores on self-report questionnaires. To identify predictors of drop-out vs completion, we analysed the following variables: demographic features (sex, marital status, school level achieved, and job status); Axis-I diagnosis; Axis-II categorical and dimensional diagnosis; and personality features. Seventeen (53%) subjects completed the treatment successfully. The drop-out rate was 47%. Patients who completed the program show a significant decrease in the number of hospitalizations, both at the end of the treatment and at 12-month follow-up. Friedman ANOVA test shows a significant decrease in suicidal attempts during and after STEPPS, and at 12-month follow-up. Analysis of drop-outs showed no significant differences with regard to sex, marital status, school level and job status between the two groups. Axis-I and Axis-II categorical diagnoses did not discriminate between the two groups. Those patients who dropped differ significantly from

Desertification in 1957-2015 Estimated from Vegetation Coverage and Climate Conditions on the Tibetan Plateau

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Cuo, L.

2017-12-01

Desert is an area that receives less than 25 cm precipitation in cold climate or 50 cm precipitation in hot climate (Miller, 1961). Others defined true desert as a region having no recorded precipitation in 12 consecutive months (McGinnies et al., 1968). According to Koppen-Gieger climate classification system, if mean annual precipitation is less than 50% of the value A calculated by mean annual temperature times 20 plus 280 if 70% or more precipitation falls in April-September, the region has desert climate; if the mean annual precipitation is within 50%-100% of the value A, the region has semi-arid or steppe climate. On the Tibetan Plateau, the above definitions will result in no desert at all or the majority of the region falling into the category of desert which is not consistent with reality based on field exploration. In this study, the fractional vegetation coverage (FPC), precipitation, soil moisture and extreme wind days are used as indices to define areas of various degrees of desertification which produces much more realistic distribution of desert areas on the plateau. The Lund-Potsdam-Jena Dynamic Vegetation model (LPJ) is used to simulate vegetation growth, succession and vegetation properties such as FPC and soil moisture on the Tibetan Plateau. Gridded daily climate data are generated to drive the model and to analyze the status and changes of various deserts including light desert, medium desert, severe desert, extremely severe desert and desert proned area. The study will reveal the status and changes of possible driving factors of desertification, as well as various kinds of desert on the Tibetan Plateau during 1957-2015.

Retreating or standing: Responses of forest species and steppe species to climate change in arid eastern central Asia

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Hong-Xiang Zhang; Ming-Li Zhang; Stewart C. Sanderson

2013-01-01

The temperature in arid Eastern Central Asia is projected to increase in the future, accompanied by increased variability of precipitation. To investigate the impacts of climate change on plant species in this area, we selected two widespread species as candidates, Clematis sibirica and C. songorica, from montane coniferous forest and arid steppe habitats respectively...

Postfire encroachment of Fabiana imbricata is real? Assessing changes of shrubland occupation during 40 years in NW Patagonia steppe

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Lasaponara, Rosa; Oddi, Facundo; Ghermandi, Luciana

2014-05-01

Landscapes are dynamic in space and time, being spatio-temporal processes of particular interest for landscape ecology. In particular, grasslands can change their structure through the expansion of shrubs in the landscape matrix. Shrub encroachment affect biodiversity as well as forage availability that is the key component of the productive use of rangelands. However, despite its recognition as a global problem, knowledge on the rates, dynamics and encroachment patterns is even scarce. For example, although it is generally accepted that fire control shrub encroachment, certain shrubby species could be favored by the occurrence of fire. In northwestern Patagonian steppe, Fabiana imbricata form large monospecific shrublands that are part of the landscape mosaic and its dynamics of regeneration is strongly related to fire. This long-lived shrub (≡ 150 years) is a typical seeder that is killed by fire and recruits seedlings almost exclusively in post-fire, establishing even-age patches. Our objective was to determine whether F. imbricata shrublands have expanded during the last 40 years in a landscape fire prone. The study area corresponds to San Ramon ranch (22,000 ha) located in northwestern Patagonia steppe, Argentina (latitude -41° 04'; longitude -70° 51'). Two distribution maps of the species were made that corresponds to the study area in 1968 and 2011. The 1968 map was elaborated from the digitalization of aerial photographs (1:45000) while the 2011 map was produced with very high resolution satellite images, current aerial photographs and GPS field data. Both maps were loaded into a GIS environment, in which landscape metrics at patch and class level were determined and then compared. From remote sensing and dendroecological techniques, we know that the study area was almost entirely affected by fires during the study period. Therefore, the comparison of both maps allows us to know post-fire changes in the shrublands spatial configuration at the landscape

Optimal balance of water use efficiency and leaf construction cost with a link to the drought threshold of the desert steppe ecotone in northern China.

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Wei, Haixia; Luo, Tianxiang; Wu, Bo

2016-09-01

In arid environments, a high nitrogen content per leaf area (Narea) induced by drought can enhance water use efficiency (WUE) of photosynthesis, but may also lead to high leaf construction cost (CC). Our aim was to investigate how maximizing Narea could balance WUE and CC in an arid-adapted, widespread species along a rainfall gradient, and how such a process may be related to the drought threshold of the desert-steppe ecotone in northern China. Along rainfall gradients with a moisture index (MI) of 0·17-0·41 in northern China and the northern Tibetan Plateau, we measured leaf traits and stand variables including specific leaf area (SLA), nitrogen content relative to leaf mass and area (Nmass, Narea) and construction cost (CCmass, CCarea), δ(13)C (indicator of WUE), leaf area index (LAI) and foliage N-pool across populations of Artemisia ordosica In samples from northern China, a continuous increase of Narea with decreasing MI was achieved by a higher Nmass and constant SLA (reduced LAI and constant N-pool) in high-rainfall areas (MI > 0·29), but by a lower SLA and Nmass (reduced LAI and N-pool) in low-rainfall areas (MI ≤ 0·29). While δ(13)C, CCmass and CCarea continuously increased with decreasing MI, the low-rainfall group had higher Narea and δ(13)C at a given CCarea, compared with the high-rainfall group. Similar patterns were also found in additional data for the same species in the northern Tibetan Plateau. The observed drought threshold where MI = 0·29 corresponded well to the zonal boundary between typical and desert steppes in northern China. Our data indicated that below a climatic drought threshold, drought-resistant plants tend to maximize their intrinsic WUE through increased Narea at a given CCarea, which suggests a linkage between leaf functional traits and arid vegetation zonation. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please

Carbon storage in permafrost and soils of the mammoth tundra-steppe biome: role in the global carbon budget

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N.S. Zimov; S.A. Zimov; A.E. Zimova; G.M. Zimova; V.I. Chuprynin; F.S. Chapin

2009-01-01

During the Last Glacial Maximum (LGM), atmospheric CO2 concentration was 80-100 ppmv lower than in preindustrial times. At that time steppe-tundra was the most extensive biome on Earth. Some authors assume that C storage in that biome was very small, similar to today's deserts, and that the terrestrial carbon (C) reservoir increased at the...

IMPACT OF TRIBE TRITICEAE VARIETIES ON STRUCTURE AND COMPETITIVENESS OF SEGETAL GROUP

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T. Z. Moskalets

2016-03-01

Full Text Available We studied the influence of varieties of tribe Triticeae (Soft Wheat, Winter Rye and Winter Triticale on the structure and competitiveness of segetal vegetation. It is shown that in the conditions of Polissya, Forest-Steppe Polissya, and Forest-Steppe ecotopes the coenotic composition of plant communities was represented mostly by annual plants and at some extent by hemycryptophytes, cryptophytes, and geophytes. The dominant weed associations of Polissya are: Erodium-Neslia; Chenopodiu-Sonchus; Galium-Setaria; Elytrigia-Convolvulus; Apera-Polygonum and Apera-Convolvulus; Polissia-steppe: Viola-Capsella; Matricaria-Galium; Elytrigia-Galeopsis; Chenopodiu-Sonchus; Thlaspi-Euphorbia; Forest-Steppe: Elytrigia-Viola; Matricaria-Taraxacum; Consolida-Convolvulus; Cirsium-Taraxacum; Galium-Stellaria; Thlaspi-Plantago, Linaria-Conyza. In terms of the Central Forest-Steppe and Eastern Polisya the medium-grown and medium ripe Wheat (Yuvivata 60 and Poliska 90, Rye (Borotba, Triticale (Slavetne, Slavetne Polipshene. and AD 256 is the most competitive towards segetal vegetation than other medium-grown and semi-dwarf varieties of such cultures. The introduction of Triticale and Rye in the structure of sown areas are an effective biological control towards segetal vegetation, particularly perennial weeds. We revealed that increasing doses of fertilizers on crops of the tribe Triticeae stimulates the growth of weeds, but the specific weight per unit area does not always correlate with density concerning cultural species. We registered the dominant competitive weeds associations in winter crops, regardless of grade, but their differentiation by population strategy and specific weight per unit area depends on the type and conditions of the specific ecotypes. We selected some six associations for the Polissya: Erodium-Neslia; Chenopodiu-Sonchus; Galium-Setaria; Elytrigia-Convolvulus; Apera-Polygonum and Apera-Convolvulus; five for Polissya Steppe

Science framework for the conservation and restoration strategy of DOI secretarial order 3336: Utilizing resilience and resistance concepts to assess threats to sagebrush ecosystems and greater sage-grouse, prioritize conservation and restoration actions, and inform management strategies

Science.gov (United States)

Chambers, Jeanne C.; Campbell, Steve; Carlson, John; Beck, Jeffrey L.; Clause, Karen J.; Dinkins, Jonathan B.; Doherty, Kevin E.; Espinosa, Shawn; Griffin, Kathleen A.; Christiansen, Thomas J.; Crist, Michele R.; Hanser, Steven E.; Havlina, Douglas W.; Henke, Kenneth F.; Hennig, Jacob D.; Kurth, Laurie L.; Maestas, Jeremy D.; Mayer, Kenneth E.; Manning, Mary E.; Mealor, Brian A.; McCarthy, Clinton; Pellant, Mike; Prentice, Karen L.; Perea, Marco A.; Pyke, David A.; Wiechman , Lief A.; Wuenschel, Amarina

2016-01-01

The Science Framework for the Conservation and Restoration Strategy of the Department of the Interior, Secretarial Order 3336 (SO 3336), Rangeland Fire Prevention, Management and Restoration, provides a strategic, multiscale approach for prioritizing areas for management and determining effective management strategies across the sagebrush biome. The emphasis of this version is on sagebrush ecosystems and greater sage-grouse. The Science Framework uses a six step process in which sagebrush ecosystem resilience to disturbance and resistance to nonnative, invasive annual grasses is linked to species habitat information based on the distribution and abundance of focal species. The predominant ecosystem and anthropogenic threats are assessed, and a habitat matrix is developed that helps decision makers evaluate risks and determine appropriate management strategies at regional and local scales. Areas are prioritized for management action using a geospatial approach that overlays resilience and resistance, species habitat information, and predominant threats. Decision tools are discussed for determining the suitability of priority areas for management and the most appropriate management actions at regional to local scales. The Science Framework and geospatial crosscut are intended to complement the mitigation strategies associated with the Greater Sage-Grouse Land Use Plan amendments for the Department of the Interior Bureaus, such as the Bureau of Land Management, and the U.S. Forest Service.

Ecological Compliance Assessment Project: 1994 Summary report

International Nuclear Information System (INIS)

Brandt, C.A.

1994-11-01

The Ecological Compliance Assessment Project (ECAP) began full operation on March 1, 1994. The project is designed around a baseline environmental data concept that includes intensive biological field surveys of key areas of the Hanford Site where the majority of Site activities occur. These surveys are conducted at biologically appropriate times of year to ensure that the data gathered are current and accurate. The data are entered into the ECAP database, which serves as a reference for the evaluation of review requests coming in to the project. This methodology provided the basis for over 90 percent of the review requests received. Field surveys conducted under ECAP are performed to document occurrence information for species of concern and to obtain habitat descriptions. There are over 200 species of concern on the Hanford Site, including plants, birds, mammals, reptiles, amphibians, fish, and invertebrates. In addition, Washington State has designated mature sagebrush-steppe habitat as a Priority Habitat meriting special protective measures. Of the projects reviewed, 17 resulted or will result in impacts to species or habitats of concern on the Hanford Site. The greatest impact has been on big sagebrush habitat. Most of the impact has been or will be within the 600 Area of the Site

Arbuscular mycorrhizal fungi regulate soil respiration and its response to precipitation change in a semiarid steppe.

Science.gov (United States)

Zhang, Bingwei; Li, Shan; Chen, Shiping; Ren, Tingting; Yang, Zhiqiang; Zhao, Hanlin; Liang, Yu; Han, Xingguo

2016-01-28

Arbuscular mycorrhizal fungi (AMF) are critical links in plant-soil continuum and play a critical role in soil carbon cycles. Soil respiration, one of the largest carbon fluxes in global carbon cycle, is sensitive to precipitation change in semiarid ecosystems. In this study, a field experiment with fungicide application and water addition was conducted during 2010-2013 in a semiarid steppe in Inner Mongolia, China, and soil respiration was continuously measured to investigate the influences of AMF on soil respiration under different precipitation regimes. Results showed that soil respiration was promoted by water addition treatment especially during drought seasons, which induced a nonlinear response of soil respiration to precipitation change. Fungicide application suppressed AMF root colonization without impacts on soil microbes. AMF suppression treatment accelerated soil respiration with 2.7, 28.5 and 37.6 g C m(-2) across three seasons, which were mainly caused by the enhanced heterotrophic component. A steeper response of soil respiration rate to precipitation was found under fungicide application treatments, suggesting a greater dampening effect of AMF on soil carbon release as water availability increased. Our study highlighted the importance of AMF on soil carbon stabilization and sequestration in semiarid steppe ecosystems especially during wet seasons.

Arbuscular mycorrhizal fungi regulate soil respiration and its response to precipitation change in a semiarid steppe

Science.gov (United States)

Zhang, Bingwei; Li, Shan; Chen, Shiping; Ren, Tingting; Yang, Zhiqiang; Zhao, Hanlin; Liang, Yu; Han, Xingguo

2016-01-01

Arbuscular mycorrhizal fungi (AMF) are critical links in plant-soil continuum and play a critical role in soil carbon cycles. Soil respiration, one of the largest carbon fluxes in global carbon cycle, is sensitive to precipitation change in semiarid ecosystems. In this study, a field experiment with fungicide application and water addition was conducted during 2010-2013 in a semiarid steppe in Inner Mongolia, China, and soil respiration was continuously measured to investigate the influences of AMF on soil respiration under different precipitation regimes. Results showed that soil respiration was promoted by water addition treatment especially during drought seasons, which induced a nonlinear response of soil respiration to precipitation change. Fungicide application suppressed AMF root colonization without impacts on soil microbes. AMF suppression treatment accelerated soil respiration with 2.7, 28.5 and 37.6 g C m-2 across three seasons, which were mainly caused by the enhanced heterotrophic component. A steeper response of soil respiration rate to precipitation was found under fungicide application treatments, suggesting a greater dampening effect of AMF on soil carbon release as water availability increased. Our study highlighted the importance of AMF on soil carbon stabilization and sequestration in semiarid steppe ecosystems especially during wet seasons.

Practice and quality improvement: successful implementation of TeamSTEPPS tools into an academic interventional ultrasound practice.

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Gupta, Rajan T; Sexton, J Bryan; Milne, Judy; Frush, Donald P

2015-01-01

The goal of this study was to implement an evidence-based teamwork system to improve communication and teamwork skills among health care professionals (TeamSTEPPS) into an academic interventional ultrasound program and to assess safety and team-work climate across team members both before and after implementation. Members of a change team (including master trainers) selected specific tools available within TeamSTEPPS to implement into an academic interventional ultrasound service. Tools selected were based on preimplementation survey data obtained from team members (n = 64: 11 attending faculty physicians, 12 clinical abdominal imaging fellows or residents, 17 sonographers, 19 nurses, and five technologist aides or administrative personnel). The survey included teamwork climate and safety climate domains from the Safety Attitudes Questionnaire. Four months after implementation, respondents were resurveyed and post-implementation data were collected. Teamwork climate scores improved from a mean of 67.9 (SD, 12.8) before implementation to a mean of 87.8 (SD, 14.1) after implementation (t = -7.6; p ultrasound practice. The most notable improvements were seen in communication among team members and role clarification. We think that this model, which has been successfully implemented in many nonradiologic areas in medical care, is also applicable in imaging practice.

Estimates of phytomass and net primary productivity in terrestrial ecosystems of the former Soviet Union identified by classified Global Vegetation Index

Energy Technology Data Exchange (ETDEWEB)

Gaston, G.G.; Kolchugina, T.P. [Oregon State Univ., Corvallis, OR (United States)

1995-12-01

Forty-two regions with similar vegetation and landcover were identified in the former Soviet Union (FSU) by classifying Global Vegetation Index (GVI) images. Image classes were described in terms of vegetation and landcover. Image classes appear to provide more accurate and precise descriptions for most ecosystems when compared to general thematic maps. The area of forest lands were estimated at 1,330 Mha and the actual area of forest ecosystems at 875 Mha. Arable lands were estimated to be 211 Mha. The area of the tundra biome was estimated at 261 Mha. The areas of the forest-tundra/dwarf forest, taiga, mixed-deciduous forest and forest-steppe biomes were estimated t 153, 882, 196, and 144 Mha, respectively. The areas of desert-semidesert biome and arable land with irrigated land and meadows, were estimated at 126 and 237 Mha, respectively. Vegetation and landcover types were associated with the Bazilevich database of phytomass and NPP for vegetation in the FSU. The phytomass in the FSU was estimated at 97.1 Gt C, with 86.8 in forest vegetation, 9.7 in natural non-forest and 0.6 Gt C in arable lands. The NPP was estimated at 8.6 Gt C/yr, with 3.2, 4.8, and 0.6 Gt C/yr of forest, natural non-forest, and arable ecosystems, respectively. The phytomass estimates for forests were greater than previous assessments which considered the age-class distribution of forest stands in the FSU. The NPP of natural ecosystems estimated in this study was 23% greater than previous estimates which used thematic maps to identify ecosystems. 47 refs., 4 figs., 2 tabs.

Sensitivity of temperate desert steppe carbon exchange to seasonal droughts and precipitation variations in Inner Mongolia, China.

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Yang, Fulin; Zhou, Guangsheng

2013-01-01

Arid grassland ecosystems have significant interannual variation in carbon exchange; however, it is unclear how environmental factors influence carbon exchange in different hydrological years. In this study, the eddy covariance technique was used to investigate the seasonal and interannual variability of CO₂ flux over a temperate desert steppe in Inner Mongolia, China from 2008 to 2010. The amounts and times of precipitation varied significantly throughout the study period. The precipitation in 2009 (186.4 mm) was close to the long-term average (183.9±47.6 mm), while the precipitation in 2008 (136.3 mm) and 2010 (141.3 mm) was approximately a quarter below the long-term average. The temperate desert steppe showed carbon neutrality for atmospheric CO₂ throughout the study period, with a net ecosystem carbon dioxide exchange (NEE) of -7.2, -22.9, and 26.0 g C m⁻² yr⁻¹ in 2008, 2009, and 2010, not significantly different from zero. The ecosystem gained more carbon in 2009 compared to other two relatively dry years, while there was significant difference in carbon uptake between 2008 and 2010, although both years recorded similar annual precipitation. The results suggest that summer precipitation is a key factor determining annual NEE. The apparent quantum yield and saturation value of NEE (NEE(sat)) and the temperature sensitivity coefficient of ecosystem respiration (R(eco)) exhibited significant variations. The values of NEE(sat) were -2.6, -2.9, and -1.4 µmol CO₂ m⁻² s⁻¹ in 2008, 2009, and 2010, respectively. Drought suppressed both the gross primary production (GPP) and R(eco), and the drought sensitivity of GPP was greater than that of R(eco). The soil water content sensitivity of GPP was high during the dry year of 2008 with limited soil moisture availability. Our results suggest the carbon balance of this temperate desert steppe was not only sensitive to total annual precipitation, but also to its seasonal distribution.

Sensitivity of temperate desert steppe carbon exchange to seasonal droughts and precipitation variations in Inner Mongolia, China.

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Fulin Yang

Full Text Available Arid grassland ecosystems have significant interannual variation in carbon exchange; however, it is unclear how environmental factors influence carbon exchange in different hydrological years. In this study, the eddy covariance technique was used to investigate the seasonal and interannual variability of CO₂ flux over a temperate desert steppe in Inner Mongolia, China from 2008 to 2010. The amounts and times of precipitation varied significantly throughout the study period. The precipitation in 2009 (186.4 mm was close to the long-term average (183.9±47.6 mm, while the precipitation in 2008 (136.3 mm and 2010 (141.3 mm was approximately a quarter below the long-term average. The temperate desert steppe showed carbon neutrality for atmospheric CO₂ throughout the study period, with a net ecosystem carbon dioxide exchange (NEE of -7.2, -22.9, and 26.0 g C m⁻² yr⁻¹ in 2008, 2009, and 2010, not significantly different from zero. The ecosystem gained more carbon in 2009 compared to other two relatively dry years, while there was significant difference in carbon uptake between 2008 and 2010, although both years recorded similar annual precipitation. The results suggest that summer precipitation is a key factor determining annual NEE. The apparent quantum yield and saturation value of NEE (NEE(sat and the temperature sensitivity coefficient of ecosystem respiration (R(eco exhibited significant variations. The values of NEE(sat were -2.6, -2.9, and -1.4 µmol CO₂ m⁻² s⁻¹ in 2008, 2009, and 2010, respectively. Drought suppressed both the gross primary production (GPP and R(eco, and the drought sensitivity of GPP was greater than that of R(eco. The soil water content sensitivity of GPP was high during the dry year of 2008 with limited soil moisture availability. Our results suggest the carbon balance of this temperate desert steppe was not only sensitive to total annual precipitation, but also to its seasonal distribution.

WILDFIRE INDUCED DEGRADATION OF WOODY VEGETATION IN DRY ZONE OF KAZAKHSTAN

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A. Terekhov

2012-08-01

Full Text Available Small bushy tree species dominate the semi-arid areas of Kazakhstan. In the course of their life cycle, they form a layer of litter that is resistant to wind transport. This small shrub species with its own litter play a significant role in the spectral characteristics of the Earth surface. Changes in the density of shrub canopy forms or replacing them with herbaceous species is accompanied by significant changes in the spectral characteristics in the visible and near infrared spectral bands in the autumn. These changes can be recorded from satellite data. LANDSAT-TM images during 1985–2007 years and MODIS data (USGS: MOD09Q1, 2000–2010 used to diagnose changes in relation between woody\\herbaceous vegetation species in the dry zone of Kazakhstan. It was found that over the past 10 years, spreading small shrub forms of semi-arid vegetation significantly decreased. There is a persistent expansion of herbal forms, leading to the semi-steppe formation areas. The mechanism of repression of wood forms constructed through the accumulation of dry plant mass during wet years, with its subsequent burnout during wildfires. In the case of a strong fire, a complete destruction of species is observed. The restoration of small shrub cover demands more than 20 years. Comparative analysis of LANDSAT-TM images showed a 10 times increasing of the fire scar areas in the test area in the central part of Kazakhstan between 1985 and 2007. According MOD09Q1 was conducted mapping small shrub forms of degradation in Kazakhstan. Reducing the area occupied by woody vegetation, semi-desert was about 30 million hectares or over 30% of their total range in Kazakhstan.

Understory cover responses to pinon-juniper treatments across tree dominance gradients in the Great Basin

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Piñon (Pinus spp.) and juniper (Juniperus spp.) trees are reduced to restore native vegetation and avoid high severity fires where they have invaded sagebrush (Artemisia tridentata Nutt.) communities. To recommend treatment implementation which avoids threshold-crossing to invasive plant dominance w...

Managed grassland alters soil N dynamics and N2O emissions in temperate steppe.

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Xu, Lijun; Xu, Xingliang; Tang, Xuejuan; Xin, Xiaoping; Ye, Liming; Yang, Guixia; Tang, Huajun; Lv, Shijie; Xu, Dawei; Zhang, Zhao

2018-04-01

Reclamation of degraded grasslands as managed grasslands has been increasingly accelerated in recent years in China. Land use change affects soil nitrogen (N) dynamics and nitrous oxide (N 2 O) emissions. However, it remains unclear how large-scale grassland reclamation will impact the grassland ecosystem as a whole. Here, we investigated the effects of the conversion from native to managed grasslands on soil N dynamics and N2O emissions by field experiments in Hulunber in northern China. Soil (0-10cm), nitrate (NO 3 - ), ammonium (NH 4 + ), and microbial N were measured in plots in a temperate steppe (Leymus chinensis grassland) and two managed grasslands (Medicago sativa and Bromus inermis grasslands) in 2011 and 2012. The results showed conversion of L. chinensis grassland to M. sativa or B. inermis grasslands decreased concentrations of NO 3 - -N, but did not change NH 4 + -N. Soil microbial N was slightly decreased by the conversion of L. chinensis grassland to M. sativa, but increased by the conversion to B. inermis. The conversion of L. chinensis grassland to M. sativa (i.e., a legume grass) increased N 2 O emissions by 26.2%, while the conversion to the B. inermis (i.e., a non-legume grass) reduced N 2 O emissions by 33.1%. The conversion from native to managed grasslands caused large created variations in soil NO 3 - -N and NH 4 + -N concentrations. Net N mineralization rates did not change significantly in growing season or vegetation type, but to net nitrification rate. These results provide evidence on how reclamation may impact the grassland ecosystem in terms of N dynamics and N 2 O emissions. Copyright © 2017. Published by Elsevier B.V.

Quantitative assessments of water-use efficiency in Temperate Eurasian Steppe along an aridity gradient.

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Yizhao Chen

Full Text Available Water-use efficiency (WUE, defined as the ratio of net primary productivity (NPP to evapotranspiration (ET, is an important indicator to represent the trade-off pattern between vegetation productivity and water consumption. Its dynamics under climate change are important to ecohydrology and ecosystem management, especially in the drylands. In this study, we modified and used a late version of Boreal Ecosystem Productivity Simulator (BEPS, to quantify the WUE in the typical dryland ecosystems, Temperate Eurasian Steppe (TES. The Aridity Index (AI was used to specify the terrestrial water availability condition. The regional results showed that during the period of 1999-2008, the WUE has a clear decreasing trend in the spatial distribution from arid to humid areas. The highest annual average WUE was in dry and semi-humid sub-region (DSH with 0.88 gC mm-1 and the lowest was in arid sub-region (AR with 0.22 gC mm-1. A two-stage pattern of WUE was found in TES. That is, WUE would enhance with lower aridity stress, but decline under the humid environment. Over 65% of the region exhibited increasing WUE. This enhancement, however, could not indicate that the grasslands were getting better because the NPP even slightly decreased. It was mainly attributed to the reduction of ET over 70% of the region, which is closely related to the rainfall decrease. The results also suggested a similar negative spatial correlation between the WUE and the mean annual precipitation (MAP at the driest and the most humid ends. This regional pattern reflected the different roles of water in regulating the terrestrial ecosystems under different aridity levels. This study could facilitate the understanding of the interactions between terrestrial carbon and water cycles, and thus contribute to a sustainable management of nature resources in the dryland ecosystems.

Quantitative assessments of water-use efficiency in Temperate Eurasian Steppe along an aridity gradient.

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Chen, Yizhao; Li, Jianlong; Ju, Weimin; Ruan, Honghua; Qin, Zhihao; Huang, Yiye; Jeelani, Nasreen; Padarian, José; Propastin, Pavel

2017-01-01

Water-use efficiency (WUE), defined as the ratio of net primary productivity (NPP) to evapotranspiration (ET), is an important indicator to represent the trade-off pattern between vegetation productivity and water consumption. Its dynamics under climate change are important to ecohydrology and ecosystem management, especially in the drylands. In this study, we modified and used a late version of Boreal Ecosystem Productivity Simulator (BEPS), to quantify the WUE in the typical dryland ecosystems, Temperate Eurasian Steppe (TES). The Aridity Index (AI) was used to specify the terrestrial water availability condition. The regional results showed that during the period of 1999-2008, the WUE has a clear decreasing trend in the spatial distribution from arid to humid areas. The highest annual average WUE was in dry and semi-humid sub-region (DSH) with 0.88 gC mm-1 and the lowest was in arid sub-region (AR) with 0.22 gC mm-1. A two-stage pattern of WUE was found in TES. That is, WUE would enhance with lower aridity stress, but decline under the humid environment. Over 65% of the region exhibited increasing WUE. This enhancement, however, could not indicate that the grasslands were getting better because the NPP even slightly decreased. It was mainly attributed to the reduction of ET over 70% of the region, which is closely related to the rainfall decrease. The results also suggested a similar negative spatial correlation between the WUE and the mean annual precipitation (MAP) at the driest and the most humid ends. This regional pattern reflected the different roles of water in regulating the terrestrial ecosystems under different aridity levels. This study could facilitate the understanding of the interactions between terrestrial carbon and water cycles, and thus contribute to a sustainable management of nature resources in the dryland ecosystems.

Predicted fire behavior and societal benefits in three eastern Sierra Nevada vegetation types

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C.A. Dicus; K. Delfino; D.R. Weise

2009-01-01

We investigated potential fire behavior and various societal benefits (air pollution removal, carbon sequestration, and carbon storage) provided by woodlands of pinyon pine (Pinus monophylla) and juniper (Juniperus californica), shrublands of Great Basin sagebrush (Artemisia tridentata) and rabbitbrush (Ericameria nauseosa...

The ELSA-Vegetation-Stack: Reconstruction of Landscape Evolution Zones (LEZ) from laminated Eifel maar sediments of the last 60,000 years

Science.gov (United States)

Sirocko, F.; Knapp, H.; Dreher, F.; Förster, M. W.; Albert, J.; Brunck, H.; Veres, D.; Dietrich, S.; Zech, M.; Hambach, U.; Röhner, M.; Rudert, S.; Schwibus, K.; Adams, C.; Sigl, P.

2016-07-01

from the Auel dry maar. The main paleobotanical indicators of MIS3 are, however, grass pollen and heliophytes, which indicate a steppe environment with scattered/patchy trees during the interstadials. The stadial phases inferred during LEZ 6 reveal initiation of eolian dust deflation. The change of the early MIS 3 forested landscape to a steppe occurred with the LEZ 7-LEZ 6 transition. This is when modern man spread in central Europe. The principle vegetation change to a steppe at 36,500 b2k must have favoured the spread of horses, an important hunting prey of modern humans. We propose accordingly that the migration of the modern humans into central Europe might have been at least partly driven by climate and associated vegetation change. The LEZ 7 encompassed the time interval 36,500 to 49,000 b2k and was characterized by a boreal forest with high abundance of pine, birch, as well as spruce during the interstadial events. Abundant charcoal fragments indicate that this taiga was under frequent drought stress with regular burning. The most unexpected finding, but corroborated by all our maar records is the dominance of thermophilous tree taxa from 49,000 to 55,000 b2k (LEZ 8). Greenland interstadials 13 and 14 were apparently the warmest of MIS 3 according to the Eifel pollen records. The preceeding LEZ 9 from 55,000 to 60,000 b2k is also dominated by spruce, but thermophilous trees were sparse. A warm early MIS3 appears plausible, because summer insolation (at 60° N) was higher in the early MIS 3 than today, ice cover was low in Scandinavia and sea-surface temperatures of the North Atlantic were almost comparable to modern values during GI-14.

Paleoecological crisis in the steppes of the Lower Volga region in the Middle of the Bronze Age (III-II centuries BC)

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Demkina, T. S.; Borisov, A. V.; Demkin, V. A.; Khomutova, T. E.; Kuznetsova, T. V.; El'tsov, M. V.; Udal'tsov, S. N.

2017-07-01

Diagnostic features of a catastrophic aridization of climate, desertification, and paleoecological crisis in steppes of the Lower Volga region have been identified on the basis of data on the morphological, chemical, and microbiological properties of paleosols under archeological monuments (burial mounds) of the Middle Bronze Age. These processes resulted in a certain convergence of the soil cover with transformation of zonal chestnut (Kastanozems) paleosols and paleosolonetzes (Solonetz Humic) into specific chestnut-like eroded saline calcareous paleosols analogous to the modern brown desert-steppe soils (Calcisols Haplic) that predominated in this region 4300-3800 years ago.1 In the second millennium BC, humidization of the climate led to the divergence of the soil cover with secondary formation of the complexes of chestnut soils and solonetzes. This paleoecological crisis had a significant effect on the economy of the tribes in the Late Catacomb and Post-Catacomb time stipulating their higher mobility and transition to the nomadic cattle breeding.

Survey for hemoparasites in imperial eagles (Aquila heliaca), steppe eagles (Aquila nipalensis), and white-tailed sea eagles (Haliaeetus albicilla) from Kazakhstan.

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Leppert, Lynda L; Layman, Seth; Bragin, Evgeny A; Katzner, Todd

2004-04-01

Prevalence of hemoparasites has been investigated in many avian species throughout Europe and North America. Basic hematologic surveys are the first step toward evaluating whether host-parasite prevalences observed in North America and Europe occur elsewhere in the world. We collected blood smears from 94 nestling imperial eagles (Aquila heliaca), five nestling steppe eagles (Aquila nipalensis), and 14 nestling white-tailed sea eagles (Haliaeetus albicilla) at Naurzum Zapovednik (Naurzum National Nature Reserve) in Kazakhstan during the summers of 1999 and 2000. In 1999, six of 29 imperial eagles were infected with Lencocytozoon toddi. Five of 65 imperial eagles and one of 14 white-tailed sea eagle were infected with L. toddi in 2000. Furthermore, in 2000, one of 65 imperial eagles was infected with Haemoproteus sp. We found no parasites in steppe eagles in either year, and no bird had multiple-species infections. These data are important because few hematologic studies of these eagle species have been conducted.

Persistent and novel threats to the biodiversity of Kazakhstan’s steppes and semi-deserts

Science.gov (United States)

Kamp, Johannes; Koshkin, Maxim A; Bragina, Tatyana M; Katzner, Todd E.; Milner-Gulland, E J; Schreiber, Dagmar; Sheldon, Robert; Shmalenko, Alyona; Smelansky, Ilya; Terraube, Julien; Urazaliev, Ruslan

2016-01-01

Temperate grasslands have suffered disproportionally from conversion to cropland, degradation and fragmentation. A large proportion of the world’s remaining near-natural grassland is situated in Kazakhstan. We aimed to assess current and emerging threats to steppe and semi-desert biodiversity in Kazakhstan and evaluate conservation research priorities. We conducted a horizon-scanning exercise among conservationists from academia and practice. We first compiled a list of 45 potential threats. These were then ranked by the survey participants according to their perceived severity, the need for research on them, and their novelty. The highest-ranked threats were related to changes in land use (leading to habitat loss and deterioration), direct persecution of wildlife, and rapid infrastructure development due to economic and population growth. Research needs were identified largely in the same areas, and the mean scores of threat severity and research need were highly correlated. Novel threats comprised habitat loss by photovoltaic and wind power stations, climate change and changes in agriculture such as the introduction of biofuels. However, novelty was not correlated with threat severity or research priority, suggesting that the most severe threats are the established ones. Important goals towards more effective steppe and semi-desert conservation in Kazakhstan include more cross-sector collaboration (e.g. by involving stakeholders in conservation and agriculture), greater allocation of funds to under-staffed areas (e.g. protected area management), better representativeness and complementarity in the protected area system and enhanced data collection for wildlife monitoring and threat assessments (including the use of citizen-science databases).

Impact of a TeamSTEPPS Trauma Nurse Academy at a Level 1 Trauma Center.

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Peters, V Kristen; Harvey, Ellen M; Wright, Andi; Bath, Jennifer; Freeman, Dan; Collier, Bryan

2018-01-01

Nurses are crucial members of the team caring for the acutely injured trauma patient. Until recently, nurses and physicians gained an understanding of leadership and supportive roles separately. With the advent of a multidisciplinary team approach to trauma care, formal team training and simulation has transpired. Since 2007, our Level I trauma system has integrated TeamSTEPPS (Team Strategies & Tools to Enhance Performance & Patient Safety; Agency for Healthcare Research and Quality, Rockville, MD) into our clinical care, joint training of nurses and physicians, using simulations with participation of all health care providers. With the increased expectations of a well-orchestrated team and larger number of emergency nurses, our program created the Trauma Nurse Academy. This academy provides a core of experienced nurses with an advanced level of training while decreasing the variability of personnel in the trauma bay. Components of the academy include multidisciplinary didactic education, the Essentials of TeamSTEPPS, and interactive trauma bay learning, to include both equipment and drug use. Once completed, academy graduates participate in the orientation and training of General Surgery and Emergency Medicine residents' trauma bay experience and injury prevention activities. Internal and published data have demonstrated growing evidence linking trauma teamwork training to knowledge and self-confidence in clinical judgment to team performance, patient outcomes, and quality of care. Although trauma resuscitations are stressful, high risk, dynamic, and a prime environment for error, new methods of teamwork training and collaboration among trauma team members have become essential. Copyright © 2017 Emergency Nurses Association. Published by Elsevier Inc. All rights reserved.

Solid-state 13C NMR experiments reveal effects of aggregate size on the chemical composition of particulate organic matter in grazed steppe soils

Science.gov (United States)

Steffens, M.; Kölbl, A.; Kögel-Knabner, I.

2009-04-01

Grazing is one of the most important factors that may reduce soil organic matter (SOM) stocks and subsequently deteriorate aggregate stability in grassland topsoils. Land use management and grazing reduction are assumed to increase the input of OM, improve the soil aggregation and change species composition of vegetation (changes depth of OM input). Many studies have evaluated the impact of grazing cessation on SOM quantity. But until today little is known about the impact of grazing cessation on the chemical quality of SOM in density fractions, aggregate size classes and different horizons. The central aim of this study was to analyse the quality of SOM fractions in differently sized aggregates and horizons as affected by increased inputs of organic matter due to grazing exclusion. We applied a combined aggregate size, density and particle size fractionation procedure to sandy steppe topsoils with different organic matter inputs due to different grazing intensities (continuously grazed = Cg, winter grazing = Wg, ungrazed since 1999 = Ug99, ungrazed since 1979 = Ug79). Three different particulate organic matter (POM; free POM, in aggregate occluded POM and small in aggregate occluded POM) and seven mineral-associated organic matter fractions were separated for each of three aggregate size classes (coarse = 2000-6300 m, medium = 630-2000 m and fine =

Contributions to the heavy metal vegetation of Rio Grande do Sul, Brasilia. Beitraege zur Schwermetallvegetation von Rio Grande do Sul, Brasilien

Energy Technology Data Exchange (ETDEWEB)

Jaeger-Porto, M.L.

1981-01-01

For the first time, a heavy-metal vegetation on top of oxidic and pyritiferous show deposits in the mining areas of Sanga Negra, Seival and Volta Grande. A subtropical mesophytic forest develops in non-metal-containing areas. The following types of vegetation can be discerned on increasing heavy-metal contents: shrub savannah, waste-dump savannah, waste-dump steppe. The physiognomy of these types of vegetation is characterized above all by narrism of woody plants showing xeromorphic configurations frequently. Those plants growing on top of pyritiferous or oxidic ores, resp., showed differences in copper resistance. Anatomical studies of the leaves of Schinus lentiscifolius revealed marked histological changes with an increase of the glandular cells and the oxalate granules were especially noticeable. The following heavy metals were examined in the soils and in the plants: Cu, Pb, Ni, Mo, Ag, Cd. Elements available to plants were established in the soils by three different methods. A number of plants were shown to have relatively high heavymetal contents in their leaves. The feru Dryopteris triphylla showed particularly high contents of lead and silver. The shrub Daphnopsis racemose, however, revealed the highest Cadmium content. Non-linear correlations between the copper contents of soil and plant were found with Schinus lentiscifolius. Certain plants are discussed as to what extent they may be used for bioprospection.

78 FR 46312 - Spruce Beetle Epidemic and Aspen Decline Management Response; Grand Mesa, Uncompahgre and...

Science.gov (United States)

2013-07-31

... treat affected stands, improve the resiliency of stands at risk of these large-scale epidemics and... across diverse vegetation ranging from sagebrush, pi[ntilde]on, juniper and ponderosa pine to Engelmann... past decade has been the hottest and driest in centuries. This climate pattern, together with...

Mountain plover nest survival in relation to prairie dog and fire dynamics in shortgrass steppe

Science.gov (United States)

Augustine, David J.; Skagen, Susan K.

2014-01-01

Disturbed xeric grasslands with short, sparse vegetation provide breeding habitat for mountain plovers (Charadrius montanus) across the western Great Plains. Maintaining local disturbance regimes through prairie dog conservation and prescribed fire may contribute to the sustainability of recently declining mountain plover populations, but these management approaches can be controversial. We estimated habitat-specific mountain plover densities and nest survival rates on black-tailed prairie dog (Cynomys ludovicianus) colonies and burns in the shortgrass steppe of northeastern Colorado. Mountain plover densities were similar on prairie dog colonies (5.9 birds/km2; 95% CI = 4.7–7.4) and sites burned during the preceding dormant season (6.7 birds/km2; 95% CI = 4.6–9.6), whereas the 29-day nest survival rate was greater on prairie dog colonies (0.81 in 2011 and 0.39 in 2012) compared to the burned sites (0.64 in 2011 and 0.17 in 2012). Reduced nest survival in 2012 compared to 2011 was associated with higher maximum daily temperatures in 2012, consistent with a previous weather-based model of mountain plover nest survival in the southern Great Plains. Measurements of mountain plover density relative to time since disturbance showed that removal of prairie dog disturbance by sylvatic plague reduced mountain plover density by 70% relative to active prairie dog colonies after 1 year. Plover densities declined at a similar rate (by 78%) at burned sites between the first and second post-burn growing season. Results indicate that black-tailed prairie dog colonies are a particularly important nesting habitat for mountain plovers in the southern Great Plains. In addition, findings suggest that prescribed burning can be a valuable means to create nesting habitat in landscapes where other types of disturbances (such as prairie dog colonies) are limited in distribution and size. 

Lichen ecology and diversity of a sagebrush steppe in Oregon: 1977 to the present

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A lichen checklist is presented of 141 species from the Lawrence Memorial Grassland Preserve and nearby lands in Wasco County, Oregon, based on collections made in the 1970s and 1990s. Collections include epiphytic, lignicolous, saxicolous, muscicolous and terricolous species. To evaluate differenc...

Organization of vegetation cover of aquatic ecosystems at Borodinskiy opencast coal mine dumps (Kansk forest-steppe, Eastern Siberia

Directory of Open Access Journals (Sweden)

D. Yu. Efimov

2016-04-01

Full Text Available The paper present the results of study of the floristic composition and importance of species of aquatic ecosystems on different types of technogenic surfaces of the Borodino coal mine and assessment of the impact of local factors on the structure and the dynamics of vegetation. The list of plant taxa containing 91 species of higher plants and 3 cha-rophytes. The largest amount of macrophytes species are Elodea canadensis Michx., Eleocharis palustris (L. Roem. & Schult., Hydrocharis morsus-ranae L., Potamogeton alpinus Balb., P. perfoliatus L., Sparganium emersum Rehm., Spirodela polyrhiza (L. Schleid., Typha latifolia L., Warnstorfia fluitans (Hedw. Loeske, Chara contraria A. Braun ex Kutz., the basis (up to 67.6‒70.9 % of vegetation mosaic of aquatic systems and differentiate its structure post-technogenic landscape. Sorensen index (QS = 0.63‒0.71 and Spearman rank correlation coefficient (rs = 0.29‒0.62, p < 0.01 values showed the greatest similarity between the species composition of the aquatic complexes arising on mineral surfaces planned dumps. The low level of similarity (QS = 0.13‒0.45; rs = 0.25‒0.34, p < 0.05 in spe-cies composition is typical fir ponds and wetlands formed around the perimeter of the heaps along the erosion of slopes. Non-parametric analysis of variance showed a statistically significant (p < 0.001 differentiation of the species composition of the variables values of the analyzed environmental factors: the direction of reclamation, type and age of geomorphic surfaces dumps. Aquatic complexes significantly complement and enrich the mosaic of man-made landscape of the Borodino coal mine, the potential of their diversity should be taken into account when developing plans and strategies for reclamation of disturbed areas.

[Life cycles of ground beetles (Coleoptera, Carabidae) from the mountain taiga and mountain forest-steppe in the Eastern Sayan].

Science.gov (United States)

Khobrakova, L Ts; Sharova, I Kh

2005-01-01

Seasonal dynamics and demographic structure was studied in 15 dominant ground beetle species in the mountain taiga and mountain forest-steppe belts of the Eastern Sayan (Okinskoe Plateau). Life cycles of the dominant ground beetle species were classified by developmental time, seasonal dynamics, and intrapopulation groups with different reproduction timing. The strategies of carabid life cycles adapted to severe mountain conditions of the Eastern Sayan were revealed.

CEF is superior to CMF for tumours with TOP2A aberrations: a Subpopulation Treatment Effect Pattern Plot (STEPP) analysis on Danish Breast Cancer Cooperative Group Study 89D

DEFF Research Database (Denmark)

Gunnarsdóttir, Katrín A; Jensen, Maj-Britt; Zahrieh, David

2010-01-01

47:725-734, 2008) demonstrated that superiority of CEF over CMF is limited to patients with TOP2A aberrations, defined as patients whose tumours have TOP2A ratio below 0.8 or above 2.0. The Subpopulation Treatment Effect Pattern Plot (STEPP) technique was applied to these data to explore the pattern...... of treatment effect relative to TOP2A and to compare that pattern to the ranges previously used to define 'aberrations'. The pattern of treatment effect illustrated by the STEPP analysis confirmed that the superiority of CEF over CMF is indeed limited to patients whose tumours have high or low TOP2A ratios...

Remote Sensing-based estimates of herbaceous aboveground biomass on the Mongolian Plateau

Science.gov (United States)

John, R.; Chen, J.; Kim, Y.; Ouyang, Z.; Park, H.; Shao, C.

2015-12-01

Grasslands comprise most of the land area on the Mongolian Plateau, which includes Mongolia (MG), and the province of Inner Mongolia (IM). Substantial land cover/use change in the recent past, driven by a combination of post-liberalization, socio-economic changes as well as extreme climatic events has resulted in degradation of grasslands in structure and function, for e.g., their carbon sequestration ability. Hence there is a need for precise estimation of above-ground biomass (AGB). In this study, we collected surface reflectance spectra from field radiometry and quadrats and line transects, which include percentage of ground cover, vegetation height, above ground biomass, and species richness, during the growing season, between the periods, 2006-2011 in IM and 2011-2015 in MG. The field sampling was stratified by the dominant vegetation types on the plateau, including the meadow steppe, typical steppe, and the desert steppe. These sampling data were used as training and validation data for developing and testing predictive models for total herbaceous vegetation, and AGB, using Landsat and MODIS-surface reflectance bands and derived vegetation indices optimized for low cover conditions. Our results show that the independent ground sampling data were significantly correlated with remotely sensed estimates. In addition to providing measures of carbon sequestration to the community, these predictive models offer decision makers and rangeland managers the ability to accurately monitor grassland dynamics, control livestock stocking rates in these remote and extensive grasslands.

Post-fire Downy Brome (Bromus tectorum) invasion at high elevation in Wyoming

Science.gov (United States)

The invasive annual grass downy brome is the most ubiquitous weed in sagebrush systems of western North America. The center of invasion has largely been the Great Basin region, but there is an increasing abundance and distribution in the Rocky Mountain States. We evaluated post-fire vegetation chang...

Spatial distribution of small-leaved forests in Kuznetskaya depression

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A. F. Gulyaeva

2016-03-01

Full Text Available The article is devoted to the spatial distribution of small-leaved forests in Kuznetskaya depression where they are forest component of zonal forest-steppe vegetation. Two levels of spatial organization were determined. According to mesorelief communities of different associations are organized into topo-ecological series. These series differ by length and set of communities. On higher level spatial distribution is controlled by climate and reflects zonal structure. Central part of the depression is occupied by Artemisio–Betuletum communities in combination with communities of Calamagrostio–Betuletum which occur in more humid habitats. Near the eastern edge of the depres­sion forest vegetation is represented by combination of Trollio–Populetum and Campanulo–Betuletum communities where the first one is more typical for the plain conditions and second one – for the mountainous environment. In south­ern part of the depression communities of Campanulo–Betuletum are widespread in combination with Saussureo–Populetum communities which localized on higher well-moisturized slopes. In north-western part syntaxonomical diversity drops down to one association – Primulo–Betuletum, and communities of Carici–Betuletum association occur across the whole depression in lowest relief positions. Climatically it is possible to distinguish two belts – forest-steppe and subtaiga. Forest-steppe is represented by two types – typical plain forest-steppe in north-western part and submountainous forest-steppe in the central part of depression. Subtaiga belt in the depression is developed on eastern edge, but in western part it exists only on mountain slopes.

Chronology of soil evolution and climatic changes in the dry steppe zone of the Northern Caucasus, Russia, during the 3rd millennium BC

NARCIS (Netherlands)

Alexandrovskiy, AL; van der Plicht, J; Belinskiy, AB; Khokhlova, OS

2001-01-01

Chrono-sequences of paleosols buried under different mounds of the large Ipatovo Kurgan, constructed during the Bronze Age, have been studied to reconstruct climatic changes in the dry steppe zone of the Northern Caucasus, Russia. Abrupt climatic and environmental changes in the third millennium BC

Thermal conditions of the grape growing season within the North-Eastern steppe land of Ukraine (on the example of Kharkiv region

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Борис Шуліка

2016-10-01

Full Text Available The article analyzes the results of the thermal conditions observations within the North-Eastern steppe land of Ukraine as one of the most important factors for successful cultivation of grapes, thus providing crop productivity. Considering the effect of thermal factors, it can be noted that the intensity and speed of life processes of plants are well- defined under temperature conditions only in the circumstances where other environmental factors are not limited. The thermal regime was initially taken into account in practice in XVII century. In XIX century the agro-climatic areas to grow grapes were determined in North-Eastern steppe land of Ukraine. Detailed studies of agro-climatic conditions of specific areas can more thoroughly to make conclusions and recommendations for the cultivation of grapes as a whole in the territory, and specifically in those areas were given. In studying the thermal balance of the territory the average and extreme temperature should be paid attention to. Characteristic features of the thermal regime are given in this paper based on the study of atmospheric phenomena, geomorphology and territories with radiation influence and water flow regime. Thermal treatment is subjected to anthropogenic influence, and in cultivating tenants can use appropriate agricultural practices (conceal bushes, warm soil and air, and even crops in protective ground, in greenhouses. Characteristically, technology of greenhouses growers is even used in Kherson region. These data can be used in neighborhood and the adjacent areas, especially they are useful for the practice of growing grapes. The possibility of successful cultivation of dozens of grape varieties in the North-Eastern steppe land of Ukraine has been well-grounded.

Direct and indirect effects of petroleum production activities on the western fence lizard (Sceloporus occidentalis) as a surrogate for the dunes sagebrush lizard (Sceloporus arenicolus).

Science.gov (United States)

Weir, Scott M; Knox, Ami; Talent, Larry G; Anderson, Todd A; Salice, Christopher J

2016-05-01

The dunes sagebrush lizard (Sceloporus arenicolus) is a habitat specialist of conservation concern limited to shin oak sand dune systems of New Mexico and Texas (USA). Because much of the dunes sagebrush lizard's habitat occurs in areas of high oil and gas production, there may be direct and indirect effects of these activities. The congeneric Western fence lizard (Sceloporus occidentalis) was used as a surrogate species to determine direct effects of 2 contaminants associated with oil and gas drilling activities in the Permian Basin (NM and TX, USA): herbicide formulations (Krovar and Quest) and hydrogen sulfide gas (H2S). Lizards were exposed to 2 concentrations of H2 S (30 ppm or 90 ppm) and herbicide formulations (1× or 2× label application rate) representing high-end exposure scenarios. Sublethal behavioral endpoints were evaluated, including sprint speed and time to prey detection and capture. Neither H2S nor herbicide formulations caused significant behavioral effects compared to controls. To understand potential indirect effects of oil and gas drilling on the prey base, terrestrial invertebrate biomass and order diversity were quantified at impacted sites to compare with nonimpacted sites. A significant decrease in biomass was found at impacted sites, but no significant effects on diversity. The results suggest little risk from direct toxic effects, but the potential for indirect effects should be further explored. © 2015 SETAC.

Plant phenolics and absorption features in vegetation reflectance spectra near 1.66 μm

Science.gov (United States)

Kokaly, Raymond F.; Skidmore, Andrew K

2015-01-01

Past laboratory and field studies have quantified phenolic substances in vegetative matter from reflectance measurements for understanding plant response to herbivores and insect predation. Past remote sensing studies on phenolics have evaluated crop quality and vegetation patterns caused by bedrock geology and associated variations in soil geochemistry. We examined spectra of pure phenolic compounds, common plant biochemical constituents, dry leaves, fresh leaves, and plant canopies for direct evidence of absorption features attributable to plant phenolics. Using spectral feature analysis with continuum removal, we observed that a narrow feature at 1.66 μm is persistent in spectra of manzanita, sumac, red maple, sugar maple, tea, and other species. This feature was consistent with absorption caused by aromatic C-H bonds in the chemical structure of phenolic compounds and non-hydroxylated aromatics. Because of overlapping absorption by water, the feature was weaker in fresh leaf and canopy spectra compared to dry leaf measurements. Simple linear regressions of feature depth and feature area with polyphenol concentration in tea resulted in high correlations and low errors (% phenol by dry weight) at the dry leaf (r2 = 0.95, RMSE = 1.0%, n = 56), fresh leaf (r2 = 0.79, RMSE = 2.1%, n = 56), and canopy (r2 = 0.78, RMSE = 1.0%, n = 13) levels of measurement. Spectra of leaves, needles, and canopies of big sagebrush and evergreens exhibited a weak absorption feature centered near 1.63 μm, short ward of the phenolic compounds, possibly consistent with terpenes. This study demonstrates that subtle variation in vegetation spectra in the shortwave infrared can directly indicate biochemical constituents and be used to quantify them. Phenolics are of lesser abundance compared to the major plant constituents but, nonetheless, have important plant functions and ecological significance. Additional research is needed to advance our understanding of the

GIS and RS soil-vegetation correlations for continental salt-lands habitats in NE Romania

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Dan Laurenţiu Stoica

2012-07-01

Full Text Available Continental saltlands have a high degree of peculiarity amongst European primary habitats and a prominent insular character. The present scientific approach establishes the degree of soil-vegetation correlation in continental slatlands patches as a measure of habitat continuity/fragmentation and soil conservation/degradation. The use of hyperspectral imagery, soil types’ distribution and vegetal associations’ conservation status reveal disturbances in relation with human induced modifications in comparison with normal plant-soil interdependence. Supervised classifications of LANDSAT satellite imagery along with detailed soil maps, ground truth data provided by accurate GPS positioning and field based plants evaluation are used to perform landscape metrics analyses. The landscape metrics approach is meant to find the balance between extent and grain in the case of saltlands habitats analyses and the degree of patches and classes inhomogeneity. These also give an insight of habitats connectivity and/or isolation in relation with land use topology and soil multiplexing. The resulting training sets developed for a representative, protected area in the county of Iaşi enhance the creation of a comprehensive mask to be used for the evaluation of larger areas in the silvan-steppes of North-Eastern Romania. The model is statistically tested to depict the degree of correlation and confidence. The final goal resides in more proper measures elaboration for the mitigation of continental saltland preservation and natural resources exploitation via agricultural and the associated activities.

Predicting posttraumatic stress disorder in children and parents following accidental child injury: evaluation of the Screening Tool for Early Predictors of Posttraumatic Stress Disorder (STEPP).

Science.gov (United States)

van Meijel, Els P M; Gigengack, Maj R; Verlinden, Eva; Opmeer, Brent C; Heij, Hugo A; Goslings, J Carel; Bloemers, Frank W; Luitse, Jan S K; Boer, Frits; Grootenhuis, Martha A; Lindauer, Ramón J L

2015-05-12

Children and their parents are at risk of posttraumatic stress disorder (PTSD) following injury due to pediatric accidental trauma. Screening could help predict those at greatest risk and provide an opportunity for monitoring so that early intervention may be provided. The purpose of this study was to evaluate the Screening Tool for Early Predictors of Posttraumatic Stress Disorder (STEPP) in a mixed-trauma sample in a non-English speaking country (the Netherlands). Children aged 8-18 and one of their parents were recruited in two academic level I trauma centers. The STEPP was assessed in 161 children (mean age 13.9 years) and 156 parents within one week of the accident. Three months later, clinical diagnoses and symptoms of PTSD were assessed in 147 children and 135 parents. We used the Anxiety Disorders Interview Schedule for DSM-IV - Child and Parent version, the Children's Revised Impact of Event Scale and the Impact of Event Scale-Revised. Receiver Operating Characteristic analyses were performed to estimate the Areas Under the Curve as a measure of performance and to determine the optimal cut-off score in our sample. Sensitivity, specificity, positive and negative predictive values were calculated. The aim was to maximize both sensitivity and negative predictive values. PTSD was diagnosed in 12% of the children; 10% of their parents scored above the cut-off point for PTSD. At the originally recommended cut-off scores (4 for children, 3 for parents), the sensitivity in our sample was 41% for children and 54% for parents. Negative predictive values were 92% for both groups. Adjusting the cut-off scores to 2 improved sensitivity to 82% for children and 92% for parents, with negative predictive values of 92% and 96%, respectively. With adjusted cut-off scores, the STEPP performed well: 82% of the children and 92% of the parents with a subsequent positive diagnosis were identified correctly. Special attention in the screening procedure is required because of a

[Spatiotemporal characteristics of MODIS NDVI in Hulunber Grassland].

Science.gov (United States)

Zhang, Hong-Bin; Yang, Gui-Xia; Wu, Wen-Bin; Li, Gang; Chen, Bao-Rui; Xin, Xiao-Ping

2009-11-01

Time-series MODIS NDVI datasets from 2000 to 2008 were used to study the spatial change trend, fluctuation degree, and occurrence time of the annual NDVImax of four typical grassland types, i.e., lowland meadow, temperate steppe, temperate meadow steppe, and upland meadow, in Hulunber Grassland. In 2000-2008, the vegetation in Hulunber Grassland presented an obvious deterioration trend. The mean annual NDVImax of the four grassland types had a great fluctuation, especially in temperate steppe where the maximum change in the mean value of annual NDVImax approximated to 50%. As for the area change of different grade grasslands, the areas with NDVImax between 0.4 and 1 accounted for about 91% of the total grassland area, which suggested the good vegetation coverage in the Grassland. However, though the areas with NDVImax values in (0.4, 0.8) showed an increasing trend, the areas with NDVImax values in (0.2, 0.4) and (0.8, 1) decreased greatly in the study period. Overall, the deteriorating grassland took up about 66.25% of the total area, and the restoring grassland took the rest. There was about 62.85% of the grassland whose NDVImax occurred between the 193rd day and the 225th day in each year, indicating that this period was the most important vegetation growth season in Hulunber Grassland.

Relationships between gas field development and the presence and abundance of pygmy rabbits in southwestern Wyoming

Science.gov (United States)

Germaine, Stephen; Carter, Sarah; Ignizio, Drew A.; Freeman, Aaron T.

2017-01-01

More than 5957 km2 in southwestern Wyoming is currently covered by operational gas fields, and further development is projected through 2030. Gas fields fragment landscapes through conversion of native vegetation to roads, well pads, pipeline corridors, and other infrastructure elements. The sagebrush steppe landscape where most of this development is occurring harbors 24 sagebrush-associated species of greatest conservation need, but the effects of gas energy development on most of these species are unknown. Pygmy rabbits (Brachylagus idahoensis) are one such species. In 2011, we began collecting three years of survey data to examine the relationship between gas field development density and pygmy rabbit site occupancy patterns on four major Wyoming gas fields (Continental Divide–Creston–Blue Gap, Jonah, Moxa Arch, Pinedale Anticline Project Area). We surveyed 120 plots across four gas fields, with plots distributed across the density gradient of gas well pads on each field. In a 1 km radius around the center of each plot, we measured the area covered by each of 10 gas field infrastructure elements and by shrub cover using 2012 National Agriculture Imagery Program imagery. We then modeled the relationship between gas field elements, pygmy rabbit presence, and two indices of pygmy rabbit abundance. Gas field infrastructure elements—specifically buried utility corridors and a complex of gas well pads, adjacent disturbed areas, and well pad access roads—were negatively correlated with pygmy rabbit presence and abundance indices, with sharp declines apparent after approximately 2% of the area consisted of gas field infrastructure. We conclude that pygmy rabbits in southwestern Wyoming may be sensitive to gas field development at levels similar to those observed for greater sage-grouse, and may suffer local population declines at lower levels of development than are allowed in existing plans and policies designed to conserve greater sage-grouse by limiting

[Assemblage effect of ground arthropod community in desert steppe shrubs with different ages].

Science.gov (United States)

Liu, Ren-Tao; Zhu, Fan; Chai, Yong-Qing

2014-01-01

Taking the 6-, 15-, 24- and 36-year-old Caragana intermedia shrubs in desert steppe as a subject, an investigation on soil properties and ground arthropod community was carried out under the shrub and in the open to probe into the assemblage effect of ground arthropod community in desert steppe shrubs with different ages. The results were as follows: 1) In the 6-year-old shrubland, significant differences were only found in soil physical properties (soil texture, soil moisture and electrical conductivity) between the microhabitats under shrub and in the open. Beginning from the 15-year-old shrubland, however, soil organic matter and nutrition (N, P) increased significantly. 2) A total of 27 groups were captured in the studied sites which dominated by Carabidae, Tenebrionidae and Formicidae. From 6- to 15-year-old shrubland, the number of dominant groups decreased while that of common groups increased for the ground arthropod community under the shrub. From 15- to 24- and 36-year-old shrubland, the difference between the microhabitats under the shrub and in the open decreased firstly, and then increased. Some special groups appeared under the shrub in the 36-year-old shrubland, and dung beetles became dominant. 3) In the 6- and 24-year-old shrublands, there were no significant differences in group richness, abundance, and diversity index between the microhabitats under the shrub and in the open. As for the 15- and 36-year-old shrublands, however, significant differences were observed. 4) The shrub age had a stronger effect on the distribution of ground arthropods living under the shrubs compared to that in the open. The changes in soil texture, pH and electrical conductivity could significantly influence on the distribution of ground arthropods under the shrub, also in the open to some degree. It was suggested that the development of shrubland had strong impact on assemblage effect of ground arthropods, which was closely correlated with the stand age and would

A Pilot Study of the Feasibility and Efficacy of the Strategies to Enhance Positive Parenting (STEPP) Program for Single Mothers of Children with ADHD

Science.gov (United States)

Chacko, Anil; Wymbs, Brian T.; Flammer-Rivera, Lizette M.; Pelham, William E.; Walker, Kathryn S.; Arnold, Fran W.; Visweswaraiah, Hema; Swanger-Gagne, Michelle; Girio, Erin L.; Pirvics, Lauma L.; Herbst, Laura

2008-01-01

Objective: The Strategies to Enhance Positive Parenting (STEPP) program was developed to address putative factors related to poor engagement in and outcomes following traditional behavioral parent training (BPT) for single mothers of children diagnosed with ADHD. Method: Twelve single mothers of children with ADHD were enrolled in an initial…

The impact of weather conditions on dynamics of Hylocomium splendens annual increment and net production in forest communities of forest-steppe zone in Khakassia

Directory of Open Access Journals (Sweden)

I. A. Goncharova

2015-12-01

Full Text Available Dynamics of annual increments of green moss Hylocomium splendens (Hedw. Schimp. in B.S.G. in the Khakassia forest-steppe zone has been studied. The values of the moss linear and phytomass increments were investigated in different habitats for 6 years. The aboveground annual production of the H. splendens in phytocenosis was estimated. Linear increments of the H. splendens growing under the tree canopy and opening between trees were not significantly different. Phytomass increments under the tree canopy are significantly higher than in the openings between trees. The density of moss mats, proportion between leaves and stems were calculated. It was revealed that climatic factors have a different degree and duration influence on the moss increments in different habitats. Linear increments of H. splendens in different habitats synchronously respond to weather factor changes. The air temperature was the most important at the beginning and the end of the vegetation period; the amount of precipitation was more important in the middle of the growth period. Phytomass increments of H. splendens in different habitats respond differently to influence of weather conditions. Phytomass increments under the tree canopy are not sensitive to air temperature, and more sensitive to precipitations in the middle of growth period than one of opening between trees. The specificity of the climatic factors’ influence on the biomass growth depends on habitat conditions.

Population ecology of small mammals on the radioactive waste management complex, Idaho National Engineering Laboratory

International Nuclear Information System (INIS)

Groves, C.R.; Keller, B.L.

1983-01-01

Species composition, diversity, biomass, population dynamics, absolute density, and movements of small mammal populations were examined on and adjacent to a solid radioactive waste disposal area in southeastern Idaho. The 15-month live-trapping study resulted in marking 2384 individuals representing 10 species of small mammals. Three vegetation types were sampled: crested wheatgrass (Agropyron cristatum) and Russian thistle (Salsola kali) habitats on the disposal area and native sagebrush (Artemisia tridentata) habitat surrounding the disposal area. The deer mouse (Peromyscus maniculatus) was the most common rodent in both disposal area habitats as well as the adjacent sagebrush habitat; Ord's kangaroo rat (Dipodomys ordii) was also an abundant rodent in all vegetation types. The montane vole (Microtus montanus) was common only in crested wheatgrass stands on the disposal area. The annual total small mammal biomass of 346 kg for the entire disposal area represents a potentially large vector for movement of radionuclides off the disposal area. However, the number of animals known to contact waste areas and traverse at least 50 m beyond the perimeter of the SDA appears to be small (8.7%)

Suitability Assessment of Satellite-Derived Drought Indices for Mongolian Grassland

Directory of Open Access Journals (Sweden)

Sheng Chang

2017-06-01

Full Text Available In Mongolia, drought is a major natural disaster that can influence and devastate large regions, reduce livestock production, cause economic damage, and accelerate desertification in association with destructive human activities. The objective of this article is to determine the optimal satellite-derived drought indices for accurate and real-time expression of grassland drought in Mongolia. Firstly, an adaptability analysis was performed by comparing nine remote sensing-derived drought indices with reference indicators obtained from field observations using several methods (correlation, consistency percentage (CP, and time-space analysis. The reference information included environmental data, vegetation growth status, and region drought-affected (RDA information at diverse scales (pixel, county, and region for three types of land cover (forest steppe, steppe, and desert steppe. Second, a meteorological index (PED, a normalized biomass (NorBio reference indicator, and the RDA-based drought CP method were adopted for describing Mongolian drought. Our results show that in forest steppe regions the normalized difference water index (NDWI is most sensitive to NorBio (maximum correlation coefficient (MAX_R: up to 0.92 and RDA (maximum CP is 87%, and is most consistent with RDA spatial distribution. The vegetation health index (VHI and temperature condition index (TCI are most correlated with the PED index (MAX_R: 0.75 and soil moisture (MAX_R: 0.58, respectively. In steppe regions, the NDWI is most closely related to soil moisture (MAX_R: 0.69 and the VHI is most related to the PED (MAX_R: 0.76, NorBio (MCC: 0.95, and RDA data (maximum CP is 89%, exhibiting the most consistency with RDA spatial distribution. In desert steppe areas, the vegetation condition index (VCI correlates best with NorBio (MAX_R: 0.92, soil moisture (MAX_R: 0.61, and RDA spatial distribution, while TCI correlates best with the PED (MAX_R: 0.75 and the RDA data (maximum CP is 79

[Algo-bacterial communities of the Kulunda steppe (Altai region, Russia) soda lakes].

Science.gov (United States)

Samylina, O S; Sapozhnikov, F V; Gaĭnanova, O Iu; Riabova, A V; Nikitin, M A; Sorokin, D Iu

2015-01-01

The composition and macroscopic structure of the floating oxygenic phototrophic communities from Kulunda steppe soda lakes (Petukhovskoe sodovoe, Tanatara VI, and Gorchiny 3) was described based on the data of the 2011 and 2012 expeditions (Winogradsky Institute of Microbiology). The algo-bacterial community with a green alga Ctenocladus circinnatus as an edificator was the typical one. Filamentous Geitlerinema sp. and Nodosilinea sp. were the dominant cyanobacteria. Apart from C. circinnatus, the algological component of the community contained unicellular green algae Dunaliella viridis and cf. Chlorella minutissima, as well as diatoms (Anomeoneis sphaerophora, Brchysira brebissonii, Brachysira zellensis, Mastogloia pusilla var. subcapitata, Nitzschia amphibia, Nitzschia communis, and Nitzschia sp.1). The latter have not been previously identified in the lakes under study. In all lakes, a considerable increase in salinity was found to result in changes in the composition and macroscopic structure of algo-bacterial communities.

[Responses of normalized difference vegetation index (NDVI) to precipitation changes on the grassland of Tibetan Plateau from 2000 to 2015.

Science.gov (United States)

Wang, Zhi Peng; Zhang, Xian Zhou; He, Yong Tao; Li, Meng; Shi, Pei Li; Zu, Jia Xing; Niu, Ben

2018-01-01

Precipitation change is an important factor in the inter-annual variation of grassland growth on the Tibetan Plateau. The total amount, distribution pattern and concentration time are three basic characteristics of precipitation change. The temporal and spatial characteristics of precipitation change were analyzed based on climate data of 145 meteorological stations on the Tibetan Plateau and nearby areas from 2000 to 2015. The total precipitation amount was characterized by annual precipitation, distribution pattern of precipitation during the year was characterized by improved precipitation concentration index (PCI), and precipitation centroid (PC) was defined to indicate the change in precipitation concentrated time. To better illustrate the response of grassland to precipitation change, vegetation growth status was characterized by the maximum value of normalized difference vegetation index (NDVI max ). Results indicated that the annual precipitation and PCI had an apparent gradient across the whole plateau and the latest PC occurred in the southern plateau. NDVI max of alpine shrub grassland was significantly correlated with the change of PCI,increased with even distribution of precipitation during growth period, and limited by the total annual precipitation. Alpine meadow did not show significantly correlations with these three indices. The inter-annual variability of NDVI max of steppe was controlled by both PCI and PC. NDVI max of alpine desert grassland was mainly controlled by annual precipitation. In addition to annual total amount of precipitation, the distribution characteristics of precipitation should be further considered when the influence of precipitation change on different types of vegetation on the Qinghai Tibet Plateau was studied.

Irrigation of steppe soils in the south of Russia: Problems and solutions (Analysis of Irrigation Practices in 1950-1990)

Science.gov (United States)

Minashina, N. G.

2009-07-01

Experience in irrigation of chernozems in the steppe zone of Russia for a period from 1950 to 1990 is analyzed. By the end of this period and in the subsequent years, the areas under irrigation reduced considerably, and the soil productivity worsened. This was caused by the improper design of irrigation systems, on the one hand, and by the low tolerance of chernozems toward increased moistening upon irrigation, on the other hand. The analysis of the factors and regimes of soil formation under irrigation conditions shows that irrigation-induced changes in the soil hydrology also lead to changes in the soil physicochemical, biochemical, and other properties. In particular, changes in the composition of exchangeable cations lead to the development of solonetzic process. In many areas, irrigation of chernozems was accompanied by the appearance of solonetzic, vertic, saline, and eroded soils. The development of soil degradation processes is described. In general, the deterioration of irrigated chernozems was related to the absence of adequate experience in irrigation of steppe soils, unskilled personnel, improper regime of irrigation, and excessively high rates of watering. In some cases, the poor quality of irrigation water resulted in the development of soil salinization and alkalization. To improve the situation, the training of personnel is necessary; the strategy of continuous irrigation should be replaced by the strategy of supplementary irrigation in the critical periods of crop development.

Framework for a National Testing and Evaluation Program Based Upon the National Stormwater Testing and Evaluation for Products and Practices (STEPP) Initiative (WERF Report INFR2R14)

Science.gov (United States)

Abstract:The National STEPP Program seeks to improve water quality by accelerating the effective implementation and adoption of innovative stormwater management technologies. Itwill attempt to accomplish this by establishing practices through highly reliable, and cost-effective S...

[Effects of cutting and reseeding on the ground-dwelling arthropod community in Caragana intermedia forest in desert steppe].

Science.gov (United States)

Liu, Ren-Tao; Chai, Yong-Qing; Yang, Xin-Guo; Song, Nai-Ping; Wang, Xin-Yun; Wang, Lei

2013-01-01

Taking a 25-year-old Caragana intermedia forest in desert steppe as test object, an investigation was conducted on the ground-dwelling arthropod community in cutting and no-cutting stands with and without reseeding, aimed to understand the effects of cutting, reseeding and their interaction on the individual number and group richness of ground-dwelling arthropod in C. intermedia forest. There were significantly lower number and richness of ground-dwelling arthropod in the open spaces than under the shrubs in the no-cutting and no-reseeding stands. Cutting, reseeding and both of them could significantly increase the number and richness of ground-dwelling arthropod in the open spaces, but not under the shrubs, compared with no cutting or reseeding. Consequently, there were no significant differences in the distribution of ground-dwelling arthropod in the open spaces and under the shrubs in the cutting, reseeding, or cutting and reseeding stands. Further, there was a similar buffer effect between cutting and reseeding on the ground-dwelling arthropod. No significant differences were observed in the ground-dwelling arthropod distribution, between cutting stand and reseeding stand, between cutting stand and cutting and reseeding stand, and between reseeding stand and cutting and reseeding stand. It was suggested that cutting, reseeding, or both of them could significantly improve the ground-dwelling arthropod diversity especially in the open spaces, being beneficial for the restoration of degraded grassland ecosystem and the rational management on artificial C. intermedia forest in desert steppe.

The “People from Cherkasy”: The “Horde’s Cossacks” and “Serving Tatars” of the Forest-Steppe Borderlands (late 14th–15th centuries

Directory of Open Access Journals (Sweden)

L.V. Vorotyntsev

2018-03-01

Full Text Available Research objectives: To consider the problem of localization and the time of the appearance of the military community called the “people from Cherkasy” and other ethnic consortiums of the “Horde’s Cossacks” and “serving Tatars” in Lithuania and the Grand Duchy of Moscow’s border areas. Research materials: Medieval Russian chronicles – Nikonovskaya, Sofiyskaya Second, Ermolinskaya, Simeonovskaya, Ustyuzhskaya, the abbreviated svod of the late 15th century, as well as the list of noble families of 1475–1605, the Rodoslovets of Glinsky princes from the Rumyantsev collection, and the Story of the Kazan Tsardom (or the Kazan Chronicle. The author also used the archaeological research results of Ukrainian archaeo­logists О.B. Suprunenko, V.V. Priymak and K.M. Mironenko in the territories of the forest-steppe zone on the Dnieper’s left bank. Results and novelty of the research: The author offers the conclusion that the “people from Cherkasy” were a Cossack military community, the so-called “Horde’s Cossacks”, that emerged in the 1430s on the lands of the middle Dnieper, with their center in Cherkasy and Kanev. Already by the late 14th – early 15th century, these lands were the official fiefs of Horde rulers (Toqtamish, Ulug-Muhammad who were forced to withdraw from the steppe to the neighboring territory of the Grand Duchy of Lithuania for military-political reasons. In the final part of the work, the author characterizes the feudal possessions of the “serving Tatars” and Cossack communities as polyethnic formations emerged in the zone of intensive ethno-cultural contacts in the forest-steppe borderlands of Russia and the Horde.

Responses of soil CO2 fluxes to short-term experimental warming in alpine steppe ecosystem, Northern Tibet.

Science.gov (United States)

Lu, Xuyang; Fan, Jihui; Yan, Yan; Wang, Xiaodan

2013-01-01

Soil carbon dioxide (CO2) emission is one of the largest fluxes in the global carbon cycle. Therefore small changes in the size of this flux can have a large effect on atmospheric CO2 concentrations and potentially constitute a powerful positive feedback to the climate system. Soil CO2 fluxes in the alpine steppe ecosystem of Northern Tibet and their responses to short-term experimental warming were investigated during the growing season in 2011. The results showed that the total soil CO2 emission fluxes during the entire growing season were 55.82 and 104.31 g C m(-2) for the control and warming plots, respectively. Thus, the soil CO2 emission fluxes increased 86.86% with the air temperature increasing 3.74°C. Moreover, the temperature sensitivity coefficient (Q 10) of the control and warming plots were 2.10 and 1.41, respectively. The soil temperature and soil moisture could partially explain the temporal variations of soil CO2 fluxes. The relationship between the temporal variation of soil CO2 fluxes and the soil temperature can be described by exponential equation. These results suggest that warming significantly promoted soil CO2 emission in the alpine steppe ecosystem of Northern Tibet and indicate that this alpine ecosystem is very vulnerable to climate change. In addition, soil temperature and soil moisture are the key factors that controls soil organic matter decomposition and soil CO2 emission, but temperature sensitivity significantly decreases due to the rise in temperature.

COMPOSITION AND FEATURES OF GEOGRAPHICAL DISTRIBUTION OF FAUNA OF ORIBATID MITES (ACARIFORMES, ORIBATIDA) IN THE TETHYS DESERT-STEPPE REGION

OpenAIRE

G. M. Abdurakhmanov; E. Z. Davudova; Yu. Yu. Ivanushenko; A. G. Abdurakhmanov

2016-01-01

Aim. The aim is to identify the similarities and differences of fauna of oribatid mites (Acariformes, Oribatida) in the Tethys desert-steppe region and analyze geographic relationships of the studied area.Methods. For the research, we used the materials collected for 5 years (2008-13) by the members of the stuff of the Department of Biology and Biodiversity (Grikurova A.A.) in the territory of the Republic of Dagestan. In addition, we referred to personal collections and publications includin...

Scientific rationale for cos lettuce growing technology Lactuca sativa var. longifolia L. in the Forest-Steppe of Ukraine

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Н. В. Лещук

2014-04-01

Full Text Available Scientifically validated items of growing technology disclosed for cos lettuce marketable products in the conditions of Forest-Steppe of Ukraine. Impact of environmental factors onto growth and development of Lactuca sativa var. longifolia L. plants. Sowing terms established for the seed of cos lettuce at field-seeded growing. Development parameters are quoted for plant productivity indices and marketable product indices for cos lettuce of national and foreign breeding. According to VCU characteristics a  typical model has been designed for the cos lettuce indices of suitability for dissemination in Ukraine.

Evaluating greater sage-grouse seasonal space use relative to leks: Implications for surface use designations in sagebrush ecosystems

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Casazza, Michael L.; Coates, Peter S.

2013-01-01

The development of anthropogenic structures, especially those related to energy resources, in sagebrush ecosystems is an important concern among developers, conservationists, and land managers in relation to greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse) populations. Sage-grouse are dependent on sagebrush ecosystems to meet their seasonal life-phase requirements, and research indicates that anthropogenic structures can adversely affect sage-grouse populations. Land management agencies have attempted to reduce the negative effects of anthropogenic development by assigning surface use (SU) designations, such as no surface occupancy, to areas around leks (breeding grounds). However, rationale for the size of these areas is often challenged. To help inform this issue, we used a spatial analysis of sage-grouse utilization distributions (UDs) to quantify seasonal (spring, summer and fall, winter) sage-grouse space use in relation to leks. We sampled UDs from 193 sage-grouse (11,878 telemetry locations) across 4 subpopulations within the Bi-State Distinct Population Segment (DPS, bordering California and Nevada) during 2003–2009. We quantified the volume of each UD (vUD) within a range of areas that varied in size and were centered on leks, up to a distance of 30 km from leks. We also quantified the percentage of nests within those areas. We then estimated the diminishing gains of vUD as area increased and produced continuous response curves that allow for flexibility in land management decisions. We found nearly 90% of the total vUD (all seasons combined) was contained within 5 km of leks, and we identified variation in vUD for a given distance related to season and migratory status. Five kilometers also represented the 95th percentile of the distribution of nesting distances. Because diminishing gains of vUD was not substantial until distances exceeded 8 km, managers should consider the theoretical optimal distances for SU designation

Artificially accelerating the reversal of desertification: cyanobacterial inoculation facilitates the succession of vegetation communities.

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Lan, Shubin; Zhang, Qingyi; Wu, Li; Liu, Yongding; Zhang, Delu; Hu, Chunxiang

2014-01-01

Desertification has been recognized as a global environmental problem, and one region experiencing ongoing desertification is the eastern edge of Qubqi Desert (Inner Mongolia). To investigate the facilitating effects of cyanobacterial inoculation technology on the desertification control along this steppe-desert transition region, artificial cyanobacterial crusts were constructed with two filamentous cyanobacteria 3 and 8 years ago combined with Salix planting. The results showed that no crusts formed after 3 years of fixation only with Salix planting, whereas after cyanobacterial inoculation, the crusts formed quickly and gradually succeed to moss crusts. During that course, topsoil environments were gradually improved, providing the necessary material basis for the regeneration of vascular plants. In this investigation, total 27 species of vascular plants had regenerated in the experimental region, mainly belonging to Asteraceae, Poaceae, Chenopodiaceae and Leguminosae. Using space time substitution, the dominant species along with the application of cyanobacterial inoculation technology succeeded from Agriophyllum squarrosum ultimately to Leymus chinensis. In addition, it was found that the shady side of the dunes is more conducive to crust development and succession of vegetation communities. Conclusively, our results indicate artificial cyanobacterial inoculation technology is an effective and desirable path for desertification control.

Refuse dumps from leaf-cutting ant nests reduce the intensity of above-ground competition among neighboring plants in a Patagonian steppe

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Farji-Brener, Alejandro G.; Lescano, María Natalia

2017-11-01

In arid environments, the high availability of sunlight due to the scarcity of trees suggests that plant competition take place mainly belowground for water and nutrients. However, the occurrence of soil disturbances that increase nutrient availability and thereby promote plant growth may enhance shoot competition between neighboring plants. We conducted a greenhouse experiment to evaluate the influence of the enriched soil patches generated by the leaf-cutting ant, Acromyrmex lobicornis, on the performance of the alien forb Carduus thoermeri (Asteraceae) under different intraspecific competition scenarios. Our results showed that substrate type and competition scenario affected mainly aboveground plant growth. As expected, plants growing without neighbors and in nutrient-rich ant refuse dumps showed more aboveground biomass than plants growing with neighbors and in nutrient-poor steppe soils. However, aboveground competition was more intense in nutrient-poor substrates: plants under shoot and full competition growing in the nutrient-rich ant refuse dumps showed higher biomass than those growing on steppe soils. Belowground biomass was similar among focal plants growing under different substrate type. Our results support the traditional view that increments in resource availability reduce competition intensity. Moreover, the fact that seedlings in this sunny habitat mainly compete aboveground illustrates how limiting factors may be scale-dependent and change in importance as plants grow.

Bird associations with shrubsteppe plant communities at the proposed reference repository location in southeastern Washington

Energy Technology Data Exchange (ETDEWEB)

Schuler, C.A.; Rickard, W.H.; Sargeant, G.A.

1988-03-01

This report provides information on te seasonal use of shrubsteppe vegetation by bird species at the RRL. Bird abundance and distribution were studied at the RRL to ensure that the DOE monitored migratory bird species pursuant to the Migratory Bird Treaty Act and to assess potential impacts of site characterization activities on bird populations. Birds were counted on two transects that together sampled an areas of 1.39 km/sup 2/. The relative abundance of birds, species richness, seasonal distribution, and the association of breeding shrubsteppe birds with major vegetation types were determined from Janurary through December 1987. Only 38 species were counted during 82 surveys. Total bird density during the nesting season (March-June) was 42.96 birdskm/sup 2/ and the density for the entire year was 26.74 birdskm/sup 2/. The characteristic nesting birds in shrubsteppe habitats were western meadowlark, sage sparrow, burrowing owl, mourning dove, horned lark, long-billed curlew, lark sparrow, and loggerhead shrike. Western meadowlark and sage sparrows were the most abundant breeding birds with an average density of 11.25 and 7.76 birdskm/sup 2/, respectively. Seasonal distribution of birds varied with species, but most species were present from March to September. Distribution and abunandance of nesting birds were correlated with habitat type. About 63% of the habitat surveyed was sagebrush, 26% was cheatgrass, and 11% was spiny hopsage. Sagebrush habitat supproted a greeater total bird density than cheatgrass or hopsage habitats. Sage sparrows were closely associated with sagebrush habitats, while western meadowlarks showed no strong habitat affinities. 22 refs., 9 figs., 6 tabs

Comparación de métodos analíticos para la determinación de materia orgánica en suelos de la región Andino-Patagónica: efectos de la vegetación y el tipo de suelo Comparison of analytical methods for determining soil organic matter in Patagonian Andean Region: effects of vegetation and soil types

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Ludmila La Manna

2007-12-01

ambiente y tipo de suelo de la estepa herbácea, que aún se mantienen por el escaso tiempo transcurrido desde la implantación del bosque. Se generaron dos modelos de regresión lineal que evidencian la relación entre MO CH y MO PI para distintos tipos de vegetación: Plantación de pino ponderosa y estepa herbácea MO PI (% = 1,37 x MO CH (% + 0,81 (R² = 0,86; n = 40 Estepa arbustiva, arbustal, y bosque denso de ciprés MO PI (% = 1,19 x MO CH (% + 1,58 (R² = 0,93; n = 60 Las ecuaciones generadas permiten comparar datos de contenido de MO obtenidos por los distintos métodos analíticos.The determination of organic matter (OM content is key for the knowledge of agricultural and forestry soil productivity. This study evaluated the relationship between OM content determined by weight loss-on ignition (OM WLOI and Walkley-Black wet oxidation method (OM WO in soils of the Patagonian Andean Region. The relation was evaluated for volcanic soils with and without amorphous components and with different vegetation types: Pinus ponderosa plantations, herbaceous steppe, shrubly steppe, shrubs and Austrocedrus chilensis forests. One hundred sampling sites were selected and composed samples were obtained from horizon A. Data were analyzed by means of analysis of variance and simple regressions. OM WO was always lower than OM WLOI. This is expectable since OM WLOI includes the total OM, whereas MO WO discriminates the strongly condensed carbon forms. Although differences in the relationship between the analytical methods for soils with and without amorphous components were not detected, a great relationship between these components and organic matter content was found. The relationship between the analytical methods varied according to the vegetation type. Soils with herbaceous steppe and pine plantations presented the greatest differences between the analytical methods. OM WO was in average 37% lower than OM WLOI for these types of vegetation, being significantly greater than

Progress Report: Stratton Ecological Research Site - An Experimental Approach to Assess Effects of Various Grazing Treatments on Vegetation and Wildlife Communities Across Managed Burns and Habitat Controls

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Erickson, Heidi J.; Aldridge, Cameron L.; Hobbs, N. Thompson

2009-01-01

Understanding how management practices affect wildlife is fundamental to wise decisions for conservation of public lands. Prescribed fire and grazing timing are two management tools frequently used within publicly owned sagebrush ecosystems. We conducted a variety of surveys in order to assess the impacts of grazing timing strategies (early summer before peak green-up, mid-summer at peak green-up, and late summer after peak green-up) in conjunction with prescribed fire on avian and small mammal populations in a high-elevation sagebrush ecosystem. Avian surveys resulted in a large detection sample size for three bird species: Brewer's sparrow (Spizella breweri), horned lark (Eremophila alpestris), and vesper sparrow (Pooecetes gramineus). Brewer's sparrows had the lowest number of detections within the mid-summer grazing treatment compared to early and late summer grazing treatments, while horned larks and vesper sparrows had higher detection frequencies within the late summer grazing treatment. Summer and fall sage-grouse (Centrocercus urophasianus) pellet counts revealed that the greatest over-winter and over-summer use by sage-grouse occurred within the early summer grazing treatment with minimal use of burn treatment areas across all grazing treatments. Deer-mice (Peromyscus maniculatus) represented approximately 90 percent of small mammals captured and were most prevalent within the mid-summer grazing treatment. Sagebrush cover was greatest within the mid-summer grazing treatment. We monitored 50 and 103 nests in 2007 and 2008, respectively. The apparent success rate for shrub-obligate nesting species was 58 percent in 2007 and 63 percent in 2008. This research will support management of sagebrush ecosystems by providing public land managers with direct comparisons of wildlife response to management regimes.

Horse-mounted invaders from the Russo-Kazakh steppe or agricultural colonists from western Central Asia? A craniometric investigation of the Bronze Age settlement of Xinjiang.

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Hemphill, Brian E; Mallory, J P

2004-07-01

Numerous Bronze Age cemeteries in the oases surrounding the Täklamakan Desert of the Tarim Basin in the Xinjiang Uyghur Autonomous Region, western China, have yielded both mummified and skeletal human remains. A dearth of local antecedents, coupled with woolen textiles and the apparent Western physical appearance of the population, raised questions as to where these people came from. Two hypotheses have been offered by archaeologists to account for the origins of Bronze Age populations of the Tarim Basin. These are the "steppe hypothesis" and the "Bactrian oasis hypothesis." Eight craniometric variables from 25 Aeneolithic and Bronze Age samples, comprising 1,353 adults from the Tarim Basin, the Russo-Kazakh steppe, southern China, Central Asia, Iran, and the Indus Valley, are compared to test which, if either, of these hypotheses are supported by the pattern of phenetic affinities possessed by Bronze Age inhabitants of the Tarim Basin. Craniometric differences between samples are compared with Mahalanobis generalized distance (d2), and patterns of phenetic affinity are assessed with two types of cluster analysis (the weighted pair average linkage method and the neighbor-joining method), multidimensional scaling, and principal coordinates analysis. Results obtained by this analysis provide little support for either the steppe hypothesis or the Bactrian oasis hypothesis. Rather, the pattern of phenetic affinities manifested by Bronze Age inhabitants of the Tarim Basin suggests the presence of a population of unknown origin within the Tarim Basin during the early Bronze Age. After 1200 B.C., this population experienced significant gene flow from highland populations of the Pamirs and Ferghana Valley. These highland populations may include those who later became known as the Saka and who may have served as "middlemen" facilitating contacts between East (Tarim Basin, China) and West (Bactria, Uzbekistan) along what later became known as the Great Silk Road. Copyright

Nomadic Life on the Steppes: An Ecocinematic Exploration of Tulpan and Cave of the Yellow Dog

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Deborah Adelman

2018-06-01

Full Text Available Ecocinema: (1 analyzes the role of visual media in responding to the environmental crisis; (2 has explicit interest in environmental justice; (3 includes a variety of genres and modes of production; (4 informs viewers of issues of ecological importance; (5 promotes ecocentric ways of framing the world; and (6 has an activist agenda. Ecocinema examines films produced by/with historically marginalized communities underrepresented in film. Using Ecocinema and Fourth Cinema (Barclay, I examined two fictional films featuring nomadic peoples of the Central Asian Steppes whose culture and ecologically low impact lifestyle are threatened and fragile in the global order. Tulpan, a 2008 Kazakh/Russian production by Kazakh-born Sergei Dvortsevoy, tells the story of Asa, a young Kazakh man, returning to his home in the Steppes to establish himself as a shepherd with his own flock. Tulpan features the long takes and slow pacing needed to “retrain the perception” of viewers. Tulpan’s biocentric focus on landscape and animals is equivalent to the focus on the human, reconsidering the human/non-human relationship. Tulpan shows one young man dreaming of a meaningful life rooted in his cultural traditions, struggling to locate himself within contemporary economic, political and cultural realities in a region underrepresented in world film. The Cave of the Yellow Dog, 2005, by Mongolian filmmaker Byambasuren Davaa, tells the story of a Mongolian nomadic family. Davaa, similar to Dvortsevoy, works in documentary and fictional films, uses professional and non-professional actors, and relies on Western funding to make her films. These two films suggest that non-commercial fictional films are an important vehicle for addressing global environmental concerns as they present stories of marginalized people and help us imagine solutions to global problems.

Specific Features of Profile Distribution and Crystallochemistry of Phyllosilicates in Soils of the Cisbaikal Forest-Steppe

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Chizhikova, N. P.; Gamzikov, G. P.; Chechetko, E. S.

2018-01-01

The mineralogical composition of agrogray, dark gray, and agro-dark gray soils (Luvic Greyzemic Retic Phaeozems); agro-dark gray residual-calcareous soils (Calcaric Cambic Phaeozems); clay-illuvial agrochernozems (Luvic Chernic Phaeozems); and agrochernozems with migrational-mycelial carbonates (Haplic Chernozems) developed in the forest-steppe of Central Siberia within the Irkutsk Depression has been studied. The clay (smectite, vermiculite, and chlorite; the proportions between them change within the soil profiles. The clay fraction also contains hydromicas, kaolinite, chlorite, and some admixture of the fine-dispersed quartz. Each type of the soils is characterized by its own distribution pattern of clay material with specific alternation of layers in the mixed-layer formations. Mixed-layer minerals of the chlorite-vermiculite type predominate in the upper horizons of texture-differentiated soils. Down the soil profile, the content of mixed-layer mica-smectitic minerals increases. In the clay fraction of arable dark gray-humus soils with residual carbonates, the distribution of the clay fraction and major mineral phases in the soil profile is relatively even. An increased content of well-crystallized kaolinite is typical of these soils. The parent material of agrochernozems has a layered character: the upper horizons are generally depleted of clay, and the middle-profile and lower horizons are characterized by the considerable kaolinite content. In general, the clay material of soils of the Tulun-Irkutsk forest-steppe differs considerably from the clay material of foreststeppe soils developed from loesslike and mantle loams in the European part of Russia. In particular, this difference is seen in the proportions between major mineral phases and between biotitic and muscovitic components, as well as in the degree of crystallinity and behavior of kaolinite and chlorite.

Impact of Climate Change on Temperate and Alpine Grasslands in China during 1982–2006

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Xiangjin Shen

2015-01-01

Full Text Available Based on GIMMS NDVI and climate data from 1982 to 2006, this study analyzed the impact of climate change on grassland in China. During the growing season, there were significant effects of precipitation on the growth of all the grassland types (P<0.05, except for meadow vegetation. For the air temperatures, there existed asymmetrical effects of maximum temperature (Tmax and minimum temperature (Tmin on grassland vegetation, especially for the temperate grasslands and alpine steppe. The growing season NDVI correlated negatively with Tmax but positively with Tmin for temperate grasslands. Seasonally, these opposite effects were only observed in summer. For alpine steppe, the growing season NDVI correlated positively with Tmax but negatively with Tmin, and this pattern of asymmetrical responses was only obvious in spring and autumn. Under the background of global asymmetric warming, more attention should be paid to this asymmetric response of grassland vegetation to daytime and night-time warming, especially when we want to predict the productivity of China’s grasslands in the future.

Orno-Cotino-Quercetum Pubescentis Ass. nova prov. on the slopes of Titel hill (Serbia

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Butorac Branislava

2008-01-01

Full Text Available Studied by many botanists from the floristic and vegetation-geographical aspects over the last hundred years, the herbaceous plant cover in dominant on Titel Hill. The first data on plant communities were registered in 1983, when a significant contribution to the study of vegetation of steppe character was made. At that time, presence of shrubby remnants of forest vegetation on Titel Hill was registered. Since 1983, fragments of typical xerothermic woods of pubescent oak have been registered.

TRENDS IN USE OF THE STEPPE LAND RESOURCES OF STAVROPOL REGION IN DIFFERENT PERIODS OF THE AGRARIAN ECONOMY

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Elena V. Pismennaya

2017-01-01

Full Text Available Abstract. The aim of this work is to examine trends in the development of agriculture and its industries, land and primary production on the territory of the steppe zone of Stavropol region during the natural history period (18502016. The analysis allows us to identify the main periods of evolution of land use and environmental and economic problems, as well as measures to overcome them. Methods. The following structure "nature – society – economy" describes the analytical and mathematical models. The structure of land use is described as the system "nature – society – economy" and is reflected in the analytical and mathematical models. They provide insight into the dynamics of change in quantitative indicators (area of agricultural areas and wetlands, crop yields, basic agri-environmental data, etc. and qualitative transformation of the latter (the presence of erosive and deflationary processes and other phenomena. In addition, careful attention is paid to the managerial decisions and activities, as well as opportunistic and market factors that influence the dynamics of the above changes during the period under review. To adjust for land development it is very important to pay attention on climatic conditions, which recently have a tendency to significant changes. Results. Analysis of economic development of the steppe areas allows to determine the structuralfunctional model of land use, to identify the main environmental and economic factors influencing its development. Main conclusion. This approach allows us to correct managerial decisions, stabilizing land use in the industrial sector.

Science Framework for the Conservation and Restoration Strategy of the Department of the Interior, Secretarial Order 3336: Using resilience and resistance concepts to assess threats to sagebrush ecosystems and sage-grouse, prioritize conservation and restoration actions, and inform management strategies

Science.gov (United States)

Jeanne C. Chambers; Jeffrey L. Beck; Steve Campbell; John Carlson; Thomas J. Christiansen; Karen J. Clause; Michele R. Crist; Jonathan B. Dinkins; Kevin E. Doherty; Shawn Espinosa; Kathleen A. Griffin; Steven E. Hanser; Douglas W. Havlina; Kenneth F. Henke; Jacob D. Hennig; Laurie L. Kurth; Jeremy D. Maestas; Mary Manning; Kenneth E. Mayer; Brian A. Mealor; Clinton McCarthy; Mike Pellant; Marco A. Perea; Karen L. Prentice; David A. Pyke; Lief A. Wiechman; Amarina Wuenschel

2016-01-01

The Science Framework for the Conservation and Restoration Strategy of the Department of the Interior, Secretarial Order 3336 (SO 3336), Rangeland Fire Prevention, Management and Restoration, provides a strategic, multiscale approach for prioritizing areas for management and determining effective management strategies across the sagebrush biome. The emphasis of this...

Sage-grouse habitat selection during winter in Alberta

Science.gov (United States)

Carpenter, Jennifer L.; Aldridge, Cameron L.; Boyce, Mark S.

2010-01-01

Greater sage-grouse (Centrocercus urophasianus) are dependent on sagebrush (Artemisia spp.) for food and shelter during winter, yet few studies have assessed winter habitat selection, particularly at scales applicable to conservation planning. Small changes to availability of winter habitats have caused drastic reductions in some sage-grouse populations. We modeled winter habitat selection by sage-grouse in Alberta, Canada, by using a resource selection function. Our purpose was to 1) generate a robust winter habitat-selection model for Alberta sage-grouse; 2) spatially depict habitat suitability in a Geographic Information System to identify areas with a high probability of selection and thus, conservation importance; and 3) assess the relative influence of human development, including oil and gas wells, in landscape models of winter habitat selection. Terrain and vegetation characteristics, sagebrush cover, anthropogenic landscape features, and energy development were important in top Akaike's Information Criterionselected models. During winter, sage-grouse selected dense sagebrush cover and homogenous less rugged areas, and avoided energy development and 2-track truck trails. Sage-grouse avoidance of energy development highlights the need for comprehensive management strategies that maintain suitable habitats across all seasons. ?? 2010 The Wildlife Society.

Productivity of seed agrocenosis of common millet (Panicum miliaceum L. at varying so­ ing w terms and techniques under the conditions of Right- Bank Forest-Steppe

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С. П. Полторецький

2013-08-01

Full Text Available The objective of the research is to improve the techno­logy of growing high-quality seeds of millet broomcorn by means of the optimization of sowing terms and methods, aimed at increasing its productivity and improving seed qualities under conditions of unstable moistening of the Right-Bank Forest-Steppe of Ukraine. Scientific literature review indicates the study of the influence of these technology elements on the formation of sowing qualities and crop capacity of millet seeds has been of schematic and occasional nature. The issue has not been studied in this region condition at all, that is why the research has considerable significance and novelty. Analysis, observations and calculations were done by means of conventional methods. Research results indicate that under conditions of unstable moistening of the southern part of the Right-Bank Forest-Steppe of Ukraine the highest yield of Slobozhanske and Lana varieties was reached at sowing in drills – 39.2 and 41.0 metric centners per hectare, respectively. That was 2.4 and 3.9 metric centners per hectare increase against the wide-row sowing. In the years with optimal hydrothermal conditions maximum seed productivity of millet broomcorn at the level of 4.24 to 4.79 metric tons per hectare (Slobozhanske variety and 4.53 to 5.28 metric tons per hectare (Lana variety was observed at postponing the sowing terms to the third decade of May. If atypical for the region hydrothermal conditions (drought or excessive moistening are forecasted du­ ring the vegetation period of millet, the highest productivity is provided by sowing in the second decade of May. Early sowing in the first decade of May causes decrease in yield at the level of 0.14 to 0.48 metric tons per hectare (Slobozhanske variety and 0.14 to 0.48 metric tons per hectare (Lana variety; if the sowing is postponed to the first decade of June, the yield increases by 0.31 to 0.77 and 0.39 to 0.84 metric tons per hectare, respectively. Early

Mid-late Holocene climate and vegetation in northeastern part of the Altai Mountains recorded in Lake Teletskoye

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Rudaya, Natalia; Nazarova, Larisa; Novenko, Elena; Babich, Valery; Kalugin, Ivan; Daryin, Andrei

2015-04-01

We report the first high-resolution (with intervals ca. 20-50 years) late-Holocene (4200 yr BP) pollen record from Lake Teletskoye, Altai Mountains, obtained from the underwater Ridge of Sofia Lepneva in 2006 (core Tel 2006). The study presents (i) the results of palynological analysis of Tel 2006; (ii) the results of spectral analysis of natural cycles based on the periodical fluctuation of taiga-biome curve; and (iii) quantitative reconstructions of the late-Holocene regional vegetation, woody coverage and climate in northern part of the Altai Mountains in order to define place of Northeast Altai on the map of the late-Holocene Central Asian environmental history. Late Holocene vegetation of the northeastern part of Altai recorded in Tel 2006 core is characterized by spread of dark-coniferous forest with structure similar to modern. Dominant trees, Siberian pine (Pinus sibirica) and Siberian fir (Abies sibirica), are the most ecological sensitive taxa between Siberian conifers (Shumilova, 1962), that as a whole suggests mild and humid climatic conditions during last 4200 years. However, changes of pollen taxa percentages and results of numerical analysis reveal pronounced fluctuation of climate and vegetation. Relatively cool and dry stage occurred prior to ca. 3500 cal yr BP. Open vegetation was widespread in the region with maximum deforestation and minimal July temperatures between 3800-3500 cal yr BP. Steppe-like communities with Artemisia, Chenopodiaceae and Cyperaceae could grow on the open sites around Lake Teletskoye. Reconstructed woody coverage is very low and varies between 29-35%. After ca. 3500 cal yr BP the area of dark-coniferous mountain taiga has significantly enlarged with maximums of woody coverages and taiga biome scores between ca. 2470-1040 cal yr BP. In the period of ~3500-2500 cal yr BP the averages July temperatures increased more than 1 0C. Climate became warmer and wetter. During last millennium (after 1040 cal yr BP) average July

Assessing the impact of time of spring vegetation renewal on growth, development and productivity of soft winter wheat varieties

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О. Л. Уліч

2014-12-01

Full Text Available Results of study focusing on impact of environmental factor – time of spring vegetation renewal (TSVR of soft winter wheat on growth and development of plants, crop productivity and modern varieties response are presented. It is found that in the central part of the Right-Bank of Forest-Steppe of Ukraine this factor is important and it should be considered in planning of spring and summer care techniques, fertilizer system, especially at spring fertilizing, use of pesticides and growth regulators, in taking a decision on reseeding or underseeding of space plants. At the same time, it was determined that the environmental effect of TSVR was not occurred every year, thus it is not always possible to forecast the type of plant development. But in such years it is possible to influence the processes of plants growth, development and survival in spring and summer periods and the formation of their productivity by introducing such intensive technologies as differential crop tending, mineral nutrition optimization, the use of plant growth regulators, trace nutrients, weed, pest and disease control agents.

Quantifying Hillslope to Watershed Erosional Response Following Wildfire

Science.gov (United States)

Vega, S.; Pierson, F. B.; Williams, C. J.; Brooks, E. S.; Strand, E. K.; Seyfried, M. S.; Murdock, M.; Pierce, J. L.; Roehner, C.; Lindsay, K.; Robichaud, P. R.; Brown, R. E.

2017-12-01

Across the western US, wildfires in sagebrush vegetation are occurring at a more frequent rate and higher severity. This has resulted in a decline of sagebrush rangeland. The changing fire regime can be attributed to invasive plant species and warming climate conditions. As the result of wildfire, protective vegetation cover is removed leaving the soil bare and exposed to erosion. Erosion following wildfire is a main concern among land managers due to the threat it poses to resources, infrastructure, and human health. Numerous studies have used artificial rainfall to assess post-fire runoff and erosion and rehabilitation treatment effectiveness. These results have found that high intensity rain events typical of summer convective storms drive post-fire erosion. The purpose of this study is to improve scientific understanding of how site-specific physical and biological attributes affect hillslope to watershed scale sediment yield on a mountainous burned sagebrush landscape. This study uses natural rainfall and a network of silt fences to quantify hillslope to watershed scale erosion response. The erosional drivers over various spatial scales were evaluated in context with vegetation recovery for a 2 year post-fire period. A network of silt fences was installed over long and short hillslope distances and in swales within the 130 ha Murphy Creek catchment in the Reynolds Creek Experimental Watershed in southwestern Idaho. We evaluated: 1) vegetation, soils, and sediment delivery across multiple spatial scales associated with 30 silt fences spanning north and south facing aspects, 2) precipitation input at two meteorological stations, and 3) watershed streamflow and sediment discharge from an existing weir. During the first and second year post-fire, the swales on both aspects produced more sediment than the short and long hillslopes. The results suggest that significant amounts of sediment and organic matter were deposited in the swales creating drifts. Sediment

Annual methane budgets of sheep grazing systems were regulated by grazing intensities in the temperate continental steppe: A two-year case study

Science.gov (United States)

Ma, Lei; Zhong, Mengying; Zhu, Yuhao; Yang, Helong; Johnson, Douglas A.; Rong, Yuping

2018-02-01

Methane (CH4) emission from animal husbandry accounts for a large percentage of anthropogenic contributions to CH4 emissions. Fully understanding of grazing management effects on the CH4 budget is essential for mitigating CH4 emissions in the temperate grazing steppe systems. Annual CH4 budgets for the sheep grazed steppes at various grazing intensities, un-grazing (UG, 0 sheep ha-1year-1), defer grazing (DG, 1.0 sheep ha-1 year-1), moderate grazing (MG, 1.43 sheep ha-1year-1), and heavy grazing (HG, 2.43 sheep ha-1year-1) were assessed across 2012-2014 in the agro-pastoral region of northern China. Annual soil CH4 uptake averaged across 2012-2014 were 1.1 ± 0.1, 2.4 ± 0.2, 2.2 ± 0.2, and 1.3 ± 0.1 kg CH4-C ha-1 for UG, DG (only 2013-2014), MG and HG sites. Non-growing season CH4 uptake comprised 50.0 ± 4.3% of annual CH4 uptake in 2012-2013 and 37.7 ± 2.0% in 2013-2014. DG and MG significantly promoted annual soil CH4 uptake (P 0.05). Bell-shaped relationship was presented between stocking rates and soil CH4 uptake (r2 = 0.59, P budgets for the grazed grasslands were -1.1 ± 0.1, 5.7 ± 0.6, 11.5 ± 1.5 and 15.5 ± 1.3 kg CH4-C ha-1 year-1 in UG, DG (only 2013-2014), MG and HG across 2012-2014. Soil CH4 uptake could offset 29.7 ± 5.6, 15.9 ± 4.3 and 6.8 ± 1.0% of total annual CH4 emissions from sheep, sheepfold and faeces in DG, MG, and HG. All grazed steppes are sources for atmospheric CH4 and the magnitude is regulated by grazing intensities. Sheep CH4 emissions for 1-g liveweight gain were 0.21, 0.32 and 0.37 g CH4-C in DG, MG and HG, respectively. DG is the recommended grazing management in this region to achieve greater herbage mass, higher sheep performance and lower CH4 emissions simultaneously.

COMPARATIVE ANALYSIS OF THE COMPOSITION OF THE TERRESTRIAL FAUNA AND FLORA OF THE TETHYS DESERT-STEPPE REGION OF PALEARARTICS, BIOGEOGRAPHIC BOUNDARIES OF THE CAUCASUS. MESSAGE 1. TERRESTRIAL FAUNA

Directory of Open Access Journals (Sweden)

G. M. Abdurakhmanov

2017-01-01

Full Text Available Aim. The aim is to conduct a comparative analysis of the composition of the terrestrial fauna of the Tethys desert-steppe region of the Palearctic.Materials and methods. The work was based on the materials collected in different republics and regions of the Caucasus and the south of the European part of Russia during 50 years (from 1961 to 2016 which are kept in various domestic and foreign institutions. Catalogs on the studied model groups were also used to conduct the research. In making the dendrograms, a cluster analysis based on the Jaccard coefficient was used.Results. A detailed analysis was carried out by model groups of the animals of the Eastern and Western Thethys complexes of the desert-steppe region of the Palearctic. Comparative analysis has shown that a significant number of species and genera of the discussed territories is characterized by an exceptionally high ratio of endemic species and superspecies taxa. Indicators of endemism in model groups fluctuate depending on the population's ability to resettle. High endemism of faunas of darkling beetles, ground beetles, click beetles and land snails in the Eastern Tethys complex was noted.Conclusion. The Caucasus (in a new interpretation is characterized by a high percentage of endemism for the studied model groups. A large number of the common Tethys genera and species in all model groups attests to their fundamental role in the overall composition of the biota against the background of powerful autochthonous centers of species-formation and, most importantly, the formation and functioning of the Palaearctic desert-steppe belt as the Tethys ocean reduced. 

New dates about the graves of Scythian archaic in the Dnieper’s Right-Bank Forest-Steppe

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Aleksandr Nazarov

2017-09-01

Full Text Available Two new complexes of the early Scythian time from the Dnieper’s Right-Bank Forest-Steppe are published. Burial in the burrow near village Pochapinci, probably, belonged to the representative of the local agricultural population. Pintaderae, which was found in this complex, may got in the region along with migrants from the Northern Caucasus and Transcaucasia after the end of the Front-Asian campaigns of the nomads.The warrior burial with dagger, axe and spear in the frame near village Voronovka belonged to the representative of the nomads, which came from the southeast and brought the early Scythian material complex.These complexes complement the source base for studying complex processes, which occurred in the east of Eastern Europe in the early Scythian time.

Organic matter dynamics along a salinity gradient in Siberian steppe soils

Science.gov (United States)

Bischoff, Norbert; Mikutta, Robert; Shibistova, Olga; Dohrmann, Reiner; Herdtle, Daniel; Gerhard, Lukas; Fritzsche, Franziska; Puzanov, Alexander; Silanteva, Marina; Grebennikova, Anna; Guggenberger, Georg

2018-01-01

Salt-affected soils will become more frequent in the next decades as arid and semiarid ecosystems are predicted to expand as a result of climate change. Nevertheless, little is known about organic matter (OM) dynamics in these soils, though OM is crucial for soil fertility and represents an important carbon sink. We aimed at investigating OM dynamics along a salinity and sodicity gradient in the soils of the southwestern Siberian Kulunda steppe (Kastanozem, non-sodic Solonchak, Sodic Solonchak) by assessing the organic carbon (OC) stocks, the quantity and quality of particulate and mineral-associated OM in terms of non-cellulosic neutral sugar contents and carbon isotopes (δ13C, 14C activity), and the microbial community composition based on phospholipid fatty acid (PLFA) patterns. Aboveground biomass was measured as a proxy for plant growth and soil OC inputs. Our hypotheses were that (i) soil OC stocks decrease along the salinity gradient, (ii) the proportion and stability of particulate OM is larger in salt-affected Solonchaks compared to non-salt-affected Kastanozems, (iii) sodicity reduces the proportion and stability of mineral-associated OM, and (iv) the fungi : bacteria ratio is negatively correlated with salinity. Against our first hypothesis, OC stocks increased along the salinity gradient with the most pronounced differences between topsoils. In contrast to our second hypothesis, the proportion of particulate OM was unaffected by salinity, thereby accounting for only soil types, while mineral-associated OM contributed > 90 %. Isotopic data (δ13C, 14C activity) and neutral sugars in the OM fractions indicated a comparable degree of OM transformation along the salinity gradient and that particulate OM was not more persistent under saline conditions. Our third hypothesis was also rejected, as Sodic Solonchaks contained more than twice as much mineral-bound OC than the Kastanozems, which we ascribe to the flocculation of OM and mineral components under

Biodiversity in temperate European grasslands: origin and conservation.

OpenAIRE

Pärtel, Meelis; Bruun, Hans Henrik; Sammul, Marek

2005-01-01

Northern Europe is in the forest zone, but wild megaherbivores have maintained grass-dominated vegetation here for the last 1.8 million years. Continuity of the grassland biome through glacialinterglacial cycles and connection to steppe vegetation has resulted in the evolution, immigration, and survival of a large number of grassland species. During the last millennia the effect of wild ungulates has been replaced by domestic grazers and hay making, and the persistence of grasslan...

Analysis of Chinook Salmon in the Columbia River from an Ecosystem Perspective. Final Report.

Energy Technology Data Exchange (ETDEWEB)

Lichatowich, James A.; Mobrand, Lars E.

1995-01-01

Ecosystem Diagnosis and Treatment (EDT) methodology was applied to the analysis of chinook salmon in the mid-Columbia subbasins which flow through the steppe and steppe-shrub vegetation zones. The EDT examines historical changes in life history diversity related to changes in habitat. The emphasis on life history, habitat and historical context is consistent with and ecosystem perspective. This study is based on the working hypothesis that the decline in chinook salmon was at least in part due to a loss of biodiversity defined as the intrapopulation life history diversity. The mid Columbia subbasins included in the study are the Deschutes, John Day, Umatilla, Tucannon and Yakima.

Late Miocene (Pannonian) Vegetation from the Northern Part of Central Paratethys

Science.gov (United States)

Kováčová, M.; Doláková, N.

2009-04-01

During Late Miocene, the Western Carpathian paleogeography started to change. The Lake Pannon retreated southwards, and the northern coast of the back arc basin was slightly elevated due to progradation of deltaic and alluvial facies, especially in the lowlands. The studied „Pannonian lake" sediments come from the Czech and Slovak parts of Central Paratethys. Changes of the sedimentary environment from deep to shallow lake and deltaic environment, followed by development of alluvial plains were noticed. Salinity crisis due to Paratethys isolation led to development of total freshwater environment to the end of this period. Samples from 3 surficial localities and 15 boreholes were palynologically studied. Occasional occurences of Dinoflagellates indicate a slightly higher salinity, whereas green algae Pediastrum, aquatic ferns Azolla, and aquatic and coastal plants (Nelumbo, Nymphaea, Myriophyllum, Sparganium, Potamogeton, Cyperaceae etc.) represent a freshwater environment. Due to paleogeographic changes and climatic oscillations the number of thermophilous taxa decreased and some of them disappeared completely from this area (f. e. Sapotaceae, Palmae). Mostly broad-leaved deciduous elements of mixed mesophytic forests (Quercus, Celtis, Carya, Tilia, Carpinus, Betula, Juglans) with some thermophilous elements admixture of Engelhardia, Castanea, Trigonobalanopsis, Symplocos, Cornaceaepollis satzveyensis generally dominate. Variously high relief of the uplifted mountainy chains created ideal conditions for higher presence of extrazonal vegetation (Cedrus, Tsuga, Picea, Cathaya) in the investigated area. Zonal type of vegetation including marshes, riparian forests with Alnus, Salix, Pterocarya, Liquidambar, Betula, Fraxinus, shrubs and lianas on dryer substrates associated riparian forest (Buxus, Ericaceae, Vitaceae, Lonicera, Rosaceae type Rubus), and coastal swamps with Taxodiaceae, Nyssa, Myrica, Sciadopitys were growing in the floodplain lowlands of Vienna Basin

Higher climate warming sensitivity of Siberian larch in small than large forest islands in the fragmented Mongolian forest steppe.

Science.gov (United States)

Khansaritoreh, Elmira; Dulamsuren, Choimaa; Klinge, Michael; Ariunbaatar, Tumurbaatar; Bat-Enerel, Banzragch; Batsaikhan, Ganbaatar; Ganbaatar, Kherlenchimeg; Saindovdon, Davaadorj; Yeruult, Yolk; Tsogtbaatar, Jamsran; Tuya, Daramragchaa; Leuschner, Christoph; Hauck, Markus

2017-09-01

Forest fragmentation has been found to affect biodiversity and ecosystem functioning in multiple ways. We asked whether forest size and isolation in fragmented woodlands influences the climate warming sensitivity of tree growth in the southern boreal forest of the Mongolian Larix sibirica forest steppe, a naturally fragmented woodland embedded in grassland, which is highly affected by warming, drought, and increasing anthropogenic forest destruction in recent time. We examined the influence of stand size and stand isolation on the growth performance of larch in forests of four different size classes located in a woodland-dominated forest-steppe area and small forest patches in a grassland-dominated area. We found increasing climate sensitivity and decreasing first-order autocorrelation of annual stemwood increment with decreasing stand size. Stemwood increment increased with previous year's June and August precipitation in the three smallest forest size classes, but not in the largest forests. In the grassland-dominated area, the tree growth dependence on summer rainfall was highest. Missing ring frequency has strongly increased since the 1970s in small, but not in large forests. In the grassland-dominated area, the increase was much greater than in the forest-dominated landscape. Forest regeneration decreased with decreasing stand size and was scarce or absent in the smallest forests. Our results suggest that the larch trees in small and isolated forest patches are far more susceptible to climate warming than in large continuous forests pointing to a grim future for the forests in this strongly warming region of the boreal forest that is also under high land use pressure. © 2017 John Wiley & Sons Ltd.

Experimental warming does not enhance soil respiration in a semiarid temperate forest-steppe ecosystem

DEFF Research Database (Denmark)

Lellei-Kovacs, E.; Kovacs-Lang, E.; Kalapos, T.

2008-01-01

are still limited. Soil respiration rate-measured monthly between April and November from 2003 to 2006-remained very low (0.09 - 1.53 mu mol CO2 m(-2) s(-1))in accordance with the moderate biological activity and low humus content of the nutrient poor, coarse sandy soil. Specific soil respiration rate...... ( calculated for unit soil organic matter content), however, was relatively high (0.36 - 7.92 mu mol CO g(-1) C(org)h(-1)) suggesting substrate limitation for soil biological activity. During the day, soil respiration rate was significantly lower at dawn than at midday, while seasonally clear temperature......The influence of simulated climate change on soil respiration was studied in a field experiment on 4 m x 5 m plots in the semiarid temperate Pannonian sand forest-steppe. This ecosystem type has low productivity and soil organic matter content, and covers large areas, yet data on soil carbon fluxes...

Tooele Army Depot - South Area Suspected Release Units. RCRA Facility Investigation - Phase 2, for SWMUs 1, 25, and 27

Science.gov (United States)

1995-11-01

metabolism before reaching the systemic circulation. Therefore, a toxic effect attributable to an active metabolite might be more pronounced if the compound...no first-pass metabolism might result in a greater dose of the toxic constituent entering the systemic circulation than if the compound were absorbed...great horned owls, red-tailed hawks, loggerhead shrikes, badgers, Ord’s kangaroo rats, horned larks, and sagebrush lizards. The vegetation types

Ordinary High Flows and the Stage-Discharge Relationship in the Arid West Region

Science.gov (United States)

2011-07-01

other authorized documents. DESTROY THIS REPORT WHEN NO LONGER NEEDED. DO NOT RETURN IT TO THE ORIGINATOR . ERDC/CRREL TR-11-12 iii Table of...occurring physical features such as bedrock banks for higher flows. A more complete description of the types of controls and their significance for...Most precipitation falls as snow Sagebrush; Xerophytic shrub vegetation Aridisols low in humus and high in calcium carbonate Most of the

Water content differences have stronger effects than plant functional groups on soil bacteria in a steppe ecosystem.

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Ximei Zhang

Full Text Available Many investigations across natural and artificial plant diversity gradients have reported that both soil physicochemical factors and plant community composition affect soil microbial communities. To test the effect of plant diversity loss on soil bacterial communities, we conducted a five-year plant functional group removal experiment in a steppe ecosystem in Inner Mongolia (China. We found that the number and composition type of plant functional groups had no effect on bacterial diversity and community composition, or on the relative abundance of major taxa. In contrast, bacterial community patterns were significantly structured by soil water content differences among plots. Our results support researches that suggest that water availability is the key factor structuring soil bacterial communities in this semi-arid ecosystem.

Evaluating Structural and Functional Characteristics of Various Ecological Patches in Different Range Conditions (Case Study: Semi -Steppe Rangeland of Aghche-Isfahan

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F. Jafari

2015-03-01

Full Text Available Rangeland condition assessment plays an important role in determining range health and applying appropriate management programs. This study aimed to evaluate the structure and function of a semi-steppe rangeland using Landscape Function Analysis technique (LFA in different land conditions in western Isfahan province, Iran. For this purpose, 4, 3 and 7 sites in different rangeland condition classes including very poor, poor, and moderate were selected respectively. In each site, a 30-meter transect was established and all kinds of patches and inter patches were identified and their lengths and widths were recorded. Also, in each ecological patch, 11 indicators of soil surface characteristics with three replications were measured, and their status was scored according to LFA method. The functionality indices of all the sites including soil stability, infiltration and nutrient cycling were measured. According to the statistical analysis results, most of the structural characteristics (number of patches, patch length, patch area index, landscape organization index and functional indices (infiltration, stability and nutrient cycling status varied significantly (α= 5% between rangeland sites with moderate and very poor condition. The changes of these structural and functional characteristics were not significant between range sites with moderate and poor, and also poor and very poor range conditions. According to the findings of this study, patch types' functionalities did not vary significantly in both rangeland sites with moderate and very poor conditions. The nutrient cycling index in patches formed by ‘forb, shrub and grass’ with poor range condition was significantly more than ‘forb’ and ‘grass’ patches. The study of range site functionality can assist managers in identifying possible ecological thresholds and prioritizing the sub-catchments and vegetation types for implementing range improvement practices.

Grass-Shrub Associations over a Precipitation Gradient and Their Implications for Restoration in the Great Basin, USA.

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Maike F Holthuijzen

Full Text Available As environmental stress increases positive (facilitative plant interactions often predominate. Plant-plant associations (or lack thereof can indicate whether certain plant species favor particular types of microsites (e.g., shrub canopies or plant-free interspaces and can provide valuable insights into whether "nurse plants" will contribute to seeding or planting success during ecological restoration. It can be difficult, however, to anticipate how relationships between nurse plants and plants used for restoration may change over large-ranging, regional stress gradients. We investigated associations between the shrub, Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis, and three common native grasses (Poa secunda, Elymus elymoides, and Pseudoroegneria spicata, representing short-, medium-, and deep-rooted growth forms, respectively, across an annual rainfall gradient (220-350 mm in the Great Basin, USA. We hypothesized that positive shrub-grass relationships would become more frequent at lower rainfall levels, as indicated by greater cover of grasses in shrub canopies than vegetation-free interspaces. We sampled aerial cover, density, height, basal width, grazing status, and reproductive status of perennial grasses in canopies and interspaces of 25-33 sagebrush individuals at 32 sites along a rainfall gradient. We found that aerial cover of the shallow rooted grass, P. secunda, was higher in sagebrush canopy than interspace microsites at lower levels of rainfall. Cover and density of the medium-rooted grass, E. elymoides were higher in sagebrush canopies than interspaces at all but the highest rainfall levels. Neither annual rainfall nor sagebrush canopy microsite significantly affected P. spicata cover. E. elymoides and P. spicata plants were taller, narrower, and less likely to be grazed in shrub canopy microsites than interspaces. Our results suggest that exploring sagebrush canopy microsites for restoration of native perennial

Climate change and its impacts on vegetation distribution and net primary productivity of the alpine ecosystem in the Qinghai-Tibetan Plateau.

Science.gov (United States)

Gao, Qingzhu; Guo, Yaqi; Xu, Hongmei; Ganjurjav, Hasbagen; Li, Yue; Wan, Yunfan; Qin, Xiaobo; Ma, Xin; Liu, Shuo

2016-06-01

Changes in climate have caused impacts on ecosystems on all continents scale, and climate change is also projected to be a stressor on most ecosystems even at the rate of low- to medium-range warming scenarios. Alpine ecosystem in the Qinghai-Tibetan Plateau is vulnerable to climate change. To quantify the climate change impacts on alpine ecosystems, we simulated the vegetation distribution and net primary production in the Qinghai-Tibetan Plateau for three future periods (2020s, 2050s and 2080s) using climate projection for RCPs (Representative Concentration Pathways) RCP4.5 and RCP8.5 scenarios. The modified Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ model) was parameter and test to make it applicable to the Qinghai-Tibetan Plateau. Climate projections that were applied to LPJ model in the Qinghai-Tibetan Plateau showed trends toward warmer and wetter conditions. Results based on climate projections indicated changes from 1.3°C to 4.2°C in annual temperature and changes from 2% to 5% in annual precipitation. The main impacts on vegetation distribution was increase in the area of forests and shrubs, decrease in alpine meadows which mainly replaced by shrubs which dominated the eastern plateau, and expanding in alpine steppes to the northwest dominated the western and northern plateau. The NPP was projected to increase by 79% and 134% under the RCP4.5 and RCP8.5. The projected NPP generally increased about 200gC·m(-2)·yr(-1) in most parts of the plateau with a gradual increase from the eastern to the western region of the Qinghai-Tibetan Plateau at the end of this century. Copyright © 2016 Elsevier B.V. All rights reserved.

Foliage biomass qualitative indices of selected forest forming tree species in Ukrainian Steppe

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Sytnyk Svitlana

2017-06-01

Full Text Available Our study objective was research on the assimilation component of aboveground biomass of trees and its correlation with mensurational indices of trees (age, diameter and height in stands of the main forest forming species in the Ukrainian Northern Steppe zone - Pinus sylvestris L. (Scots pine and Robinia pseudoacacia L. (Black locust. The research was carried out in forest stands subordinated to the State Agency of Forest Resources of Ukraine. We used experimental data collected on sample plots established during years 2014-2016. The main research results prove that the foliage share in the tree greenery biomass structure had a wide range of values. For both investigated species, a positive correlation was found between the dry matter content in the tree foliage and the tree age, height and diameter. The foliage share in tree greenery biomass decreased with increasing mensurational index values. Correlation analysis revealed linear relationships between the mensurational indices and the discussed aboveground live biomass parameters. The closest correlation was observed between the stand age, mean stand diameter, mean stand height and dry matter content in the foliage.

Desert Dust and Health: A Central Asian Review and Steppe Case Study

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Troy Sternberg

2017-11-01

Full Text Available In Asian deserts environmental and anthropomorphic dust is a significant health risk to rural populations. Natural sources in dry landscapes are exacerbated by human activities that increase the vulnerability to dust and dust-borne disease vectors. Today in Central and Inner Asian drylands, agriculture, mining, and rapid development contribute to dust generation and community exposure. Thorough review of limited dust investigation in the region implies but does not quantify health risks. Anthropogenic sources, such as the drying of the Aral Sea, highlight the shifting dust dynamics across the Central EurAsian steppe. In the Gobi Desert, our case study in Khanbogd, Mongolia addressed large-scale mining’s potential dust risk to the health of the local population. Dust traps showed variable exposure to particulates among herder households and town residents; dust density distribution indicated that sources beyond the mine need to be considered when identifying particulate sources. Research suggests that atmospheric dust from multiple causes may enhance human particulate exposure. Greater awareness of dust in greater Central Asia reflects community concern about related health implications. Future human well-being in the region will require more thorough information on dust emissions in the changing environment.

Desert Dust and Health: A Central Asian Review and Steppe Case Study.

Science.gov (United States)

Sternberg, Troy; Edwards, Mona

2017-11-03

In Asian deserts environmental and anthropomorphic dust is a significant health risk to rural populations. Natural sources in dry landscapes are exacerbated by human activities that increase the vulnerability to dust and dust-borne disease vectors. Today in Central and Inner Asian drylands, agriculture, mining, and rapid development contribute to dust generation and community exposure. Thorough review of limited dust investigation in the region implies but does not quantify health risks. Anthropogenic sources, such as the drying of the Aral Sea, highlight the shifting dust dynamics across the Central EurAsian steppe. In the Gobi Desert, our case study in Khanbogd, Mongolia addressed large-scale mining's potential dust risk to the health of the local population. Dust traps showed variable exposure to particulates among herder households and town residents; dust density distribution indicated that sources beyond the mine need to be considered when identifying particulate sources. Research suggests that atmospheric dust from multiple causes may enhance human particulate exposure. Greater awareness of dust in greater Central Asia reflects community concern about related health implications. Future human well-being in the region will require more thorough information on dust emissions in the changing environment.

VEGETATION MAPPING IN WETLANDS

Directory of Open Access Journals (Sweden)

F. PEDROTTI

2004-01-01

Full Text Available The current work examines the main aspects of wetland vegetation mapping, which can be summarized as analysis of the ecological-vegetational (ecotone gradients; vegetation complexes; relationships between vegetation distribution and geomorphology; vegetation of the hydrographic basin lo which the wetland in question belongs; vegetation monitoring with help of four vegetation maps: phytosociological map of the real and potential vegetation, map of vegetation dynamical tendencies, map of vegetation series.

Vegetation dynamics during the Last Interglacial-Glacial cycle in the Arno coastal plain (Tuscany, western Italy): location of a new tree refuge

Science.gov (United States)

Lucchi, M. Ricci

2008-12-01

Pollen analysis of the pre-Last Glacial Maximum succession of a 105 m-long continuous core from Tirrenia (Tuscany) provides evidence for the existence of an area of relatively high ecological stability where the effects of climate change were mitigated. The chronological framework of the vegetation record, spanning the Last Interglacial-Glacial cycle, was established by (i) AMS 14C dating, (ii) correlation with well-dated pollen sequences, and (iii) local stratigraphical constraints. A high lithological and sedimentological variability, with facies associations changing from fluvial to alluvial and coastal plain, enhances the palaeoenvironmental control on pollen distribution, thus helping to discriminate the impact of local factors on vegetation history. The most remarkable evidence, however, is represented by the continuous record of temperate trees throughout the whole glacial period, which provides useful indications on the location and nature of cold stage refugia. Most of the vegetation changes recorded in the core can be compared to the vegetation history of the Last Interglacial-Glacial cycle from southern Europe as a whole. In addition, local geographic and environmental features account for a more complex and varied floristic composition. Only the last phase of the Penultimate Glacial (MIS6), which was characterized by the diffusion of an arid steppe tundra, is recorded at the base of the core. The subsequent Last Interglacial (MIS5e) interval shows a poor and scattered pollen content due to the instability of the sedimentary environment. Nevertheless, it provides evidence of both global and local controls on vegetation dynamics, as indicated by the initial expansion of thermophilous forests and the remarkably late diffusion of conifers ( Pinus-Abies-Picea forests), respectively. Similarly, the transition to the Last Glacial (MIS5b and 5a in the core) is characterized by a reduced vegetation response to the typical stadial/interstadial climate variability

Canopy Modeling of Aquatic Vegetation: Construction of Submerged Vegetation Index

Science.gov (United States)

Ma, Z.; Zhou, G.

2018-04-01

The unique spectral characteristics of submerged vegetation in wetlands determine that the conventional terrestrial vegetation index cannot be directly employed to species identification and parameter inversion of submerged vegetation. Based on the Aquatic Vegetation Radiative Transfer model (AVRT), this paper attempts to construct an index suitable for submerged vegetation, the model simulated data and a scene of Sentinel-2A image in Taihu Lake, China are utilized for assessing the performance of the newly constructed indices and the existent vegetation indices. The results show that the angle index composed by 525 nm, 555 nm and 670 nm can resist the effects of water columns and is more sensitive to vegetation parameters such as LAI. Furthermore, it makes a well discrimination between submerged vegetation and water bodies in the satellite data. We hope that the new index will provide a theoretical basis for future research.

CHRONOLOGY AND DYNAMICS OF ANCIENT POTTERY TRADITIONS' DISSEMINATION IN STEPPES OF THE LOWER VOLGA REGION

DEFF Research Database (Denmark)

Vybornov, Aleksandr A.; Vasilyeva, Irina N.; Kulkova, Marianna A.

2018-01-01

The territory of the Lower Volga plays an important role in the study of the Neolithic of Eastern Europe. The leading indicator of this epoch is pottery. Determining the chronology of pottery making is one of the most complex issues. Over the past ten years, a large number of radiocarbon dates (43......) have been obtained on various materials: coal, bones, organic materials in pottery, crusts, humus. They allowed accurate determining of the initial time of appearance of the most ancient crockery in the Lower Volga region - the middle of the 7th millennium BC. The authors determine the chronological...... analysis made it possible to clarify the genesis, the features of the dynamics and the further destiny of pottery in the region. The combination of the latest data allows referring the Neolithic monuments of steppe territory of the Lower Volga to the area of the ancient pottery in Eastern Europe. A...

Identification sources of pollen spectra in dry and wet atmospheric deposition in the forest-steppe zone of Altai Krai (Russia)

Science.gov (United States)

Ryabchinskaya, Natalia; Nenasheva, Galina; Malygina, Natalia

2015-04-01

Pollen spectra circulating in the atmosphere contain the important information about primary biological aerosol particles (PBAP), worldwide interest in which has significantly increased in recent decades [Despres, 2012]. It is related to the fact that many researchers suggest primary aerosols as a condensation nucleus significantly affected on the formation of clouds and precipitation and, consequently, on the hydrological cycle and climate, especially at the regional level [Andreae et al., 2008; Poschlet et al., 2010; Prenni et al., 2009]. We present the comparison of pollen spectra obtained during the dry and wet atmospheric deposition in Altai Krai (Russia) and identification of the sources/regions of their receipts. Altai Krai is located in the center of the Eurasian continent, at the border of several natural and climatic zones. A significant part of the region's territory is characterized as a forest-steppe zone with a lot of natural and anthropogenic landscapes, accompanied by continental climate. It provides a rich diversity of natural vegetation and cultural associations. During last 10 years pollen grains has been monitored in the airspace of Barnaul city (the capital of Altai Krai) located in the central part of the forest-steppe zone). During the monitoring, the attempts to determine the origin of pollen spectra (local or introduced) were made as well. In the long-term average dates of the first wave of dusting in the spring season 2014 Burkard pollen traps were used in order to monitor the airspace in Barnaul, namely dry deposition of pollen grains [Nenasheva, 2013]. To estimate the wet deposition PBAP (pollen), which can reach 80% in the middle latitudes, precipitation sampler were installed close to Burkard pollen traps in order to sample precipitation. The samples were filtered through a filter having a pore diameter of 1 µm, then prepared and examined for the presence of pollen grains. The comparison of the results of pollen analysis of 10 samples

Variations in Growing-Season NDVI and Its Response to Permafrost Degradation in Northeast China

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Jinting Guo

2017-04-01

Full Text Available Permafrost is extremely sensitive to climate change. The degradation of permafrost has strong and profound effects on vegetation. The permafrost zone of northeastern China is the second largest region of permafrost in China and lies on the south edge of the Eurasian cryolithozone. This study analyzed the spatiotemporal variations of the growing-season Normalization Difference Vegetation Index (NDVI in the permafrost zone of northeastern China and analyzed the correlation between NDVI and ground surface temperatures (GST during the years 1981–2014. Mean growing-season NDVI (MGS-NDVI experienced a marked increase of 0.003 year−1 across the entire permafrost zone. The spatial dynamics of vegetation cover had a high degree of heterogeneity on a per pixel scale. The MGS-NDVI value increased significantly (5% significance level in 80.57%, and this increase was mostly distributed in permafrost zone except for the western steppe region. Only 7.72% experienced a significant decrease in NDVI, mainly in the cultivated and steppe portions. In addition, MGS-NDVI increased significantly with increasing growing-season mean ground surface temperature (GS-MGST. Our results suggest that a warming of GS-MGST (permafrost degradation in the permafrost region of northeastern China played a positive role in increasing plant growth and activities. Although increasing ground surface temperature resulted in increased vegetation cover and growth in the short time of permafrost degradation, from the long term point of view, permafrost degradation or disappearance may weaken or even hinder vegetation activities.

Possible climate warming effects on vegetation, forests, biotic (insect, pathogene) disturbances and agriculture in Central Siberia for 1960- 2050

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Tchebakova, N. M.; Parfenova, E. I.; Soja, A. J.; Lysanova, G. I.; Baranchikov, Y. N.; Kuzmina, N. A.

2012-04-01

Regional Siberian studies have already registered climate warming over the last half a century (1960-2010). Our analysis showed that winters are already 2-3°C warmer in the north and 1-2°C warmer in the south by 2010. Summer temperatures increased by 1°C in the north and by 1-2°C in the south. Change in precipitation is more complicated, increasing on average 10% in middle latitudes and decreasing 10-20% in the south, promoting local drying in already dry landscapes. Our goal was to summarize results of research we have done for the last decade in the context of climate warming and its consequences for biosystems in Central Siberia. We modeled climate change effects on vegetation shifts, on forest composition and agriculture change, on the insect Siberian moth (Dendrolimus suprans sibiricus Tschetv) and pathogene (Lophodermium pinastri Chev) ranges in Central Siberia for a century (1960-2050) based on historical climate data and GCM-predicted data. Principal results are: In the warmer and drier climate projected by these scenarios, Siberian forests are predicted to decrease and shift northwards and forest-steppe and steppe ecosystems are predicted to dominate over 50% of central Siberia due to the dryer climate by 2080. Permafrost is not predicted to thaw deep enough to sustain dark (Pinus sibirica, Abies sibirica, and Picea obovata) taiga. Over eastern Siberia, larch (Larix dahurica) taiga is predicted to continue to be the dominant zonobiome because of its ability to withstand continuous permafrost. The model also predicts new temperate broadleaf forest and forest-steppe habitats; At least half of central Siberia is predicted to be climatically suitable for agriculture at the end of the century although potential croplands would be limited by the availability of suitable soils agriculture in central Siberia would likely benefit from climate warming Crop production may twofold increase as climate warms during the century; traditional crops (grain, potato

Organic matter dynamics along a salinity gradient in Siberian steppe soils

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N. Bischoff

2018-01-01

Full Text Available Salt-affected soils will become more frequent in the next decades as arid and semiarid ecosystems are predicted to expand as a result of climate change. Nevertheless, little is known about organic matter (OM dynamics in these soils, though OM is crucial for soil fertility and represents an important carbon sink. We aimed at investigating OM dynamics along a salinity and sodicity gradient in the soils of the southwestern Siberian Kulunda steppe (Kastanozem, non-sodic Solonchak, Sodic Solonchak by assessing the organic carbon (OC stocks, the quantity and quality of particulate and mineral-associated OM in terms of non-cellulosic neutral sugar contents and carbon isotopes (δ13C, 14C activity, and the microbial community composition based on phospholipid fatty acid (PLFA patterns. Aboveground biomass was measured as a proxy for plant growth and soil OC inputs. Our hypotheses were that (i soil OC stocks decrease along the salinity gradient, (ii the proportion and stability of particulate OM is larger in salt-affected Solonchaks compared to non-salt-affected Kastanozems, (iii sodicity reduces the proportion and stability of mineral-associated OM, and (iv the fungi : bacteria ratio is negatively correlated with salinity. Against our first hypothesis, OC stocks increased along the salinity gradient with the most pronounced differences between topsoils. In contrast to our second hypothesis, the proportion of particulate OM was unaffected by salinity, thereby accounting for only  <  10 % in all three soil types, while mineral-associated OM contributed  >  90 %. Isotopic data (δ13C, 14C activity and neutral sugars in the OM fractions indicated a comparable degree of OM transformation along the salinity gradient and that particulate OM was not more persistent under saline conditions. Our third hypothesis was also rejected, as Sodic Solonchaks contained more than twice as much mineral-bound OC than the Kastanozems, which we ascribe

Relaciones polen-vegetación de algunos taxa de la estepa patagónica (Argentina Pollen-vegetation relationships of some taxa from the Patagonian steppe (Argentina

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LIDIA S. BURRY

2001-06-01

Full Text Available La aplicación de un análisis de regresión lineal simple a datos de lluvia de polen y de vegetación, en una zona de la Patagonia (Provincia de Chubut, Argentina permitió relacionar cuantitativamente los porcentajes de lluvia polínica y de cobertura de la vegetación para los taxa Poaceae, Papilionoideae, tipo Senecio y Mulinum spinosum. Se obtuvo un buen ajuste de las rectas de regresión para cada uno de los taxa considerados, con coeficientes de correlación r de Pearson altos para M. spinosum (0,82 y tipo Senecio (0,81 y coeficientes algo menores en el caso de Poaceae (0,66 y Papilionoideae (0,61. Estas regresiones permitieron inferir la presencia o ausencia de polen regional y el valor predictivo de la presencia de polen en ausencia de la vegetación que lo produce. Al respecto, la lluvia de polen estudiada incluye el aporte regional (excepto Papilionoideae aun cuando M. spinosum tiene una baja contribución. Esta sobrerrepresentación es atribuible al transporte de larga distancia, a través de los vientos que provienen del oeste. Estas relaciones cuantitativas nos permitirán extrapolar cambios vegetacionales pasados en estos taxa a partir de espectros de polen fósil para el área de estudioThe use of simple linear regression to data of pollen rain and vegetation cover in Patagonia (Province of Chubut, Argentina allowed us to develop quantitative relationships between modern pollen rain perecentages and vegetation cover for the taxa Poaceae, Papilionoideae, Senecio type, and Mulinum spinosum. The analysis revealed a good fit of data to regression lines for all taxa, with high Pearson r coefficient values in the case of M. spinosum (0.82 and Senecio type (0.81, and somewhat lower values in the case of Poaceae (0.66 and Papilionoideae (0.61. These regressions allowed us to infer the presence or absence of regional pollen and predict the quantity of pollen in the absence of the vegetation producing it. In this regard, the studied pollen

Fire rehabilitation effectiveness: a chronosequence approach for the Great Basin

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Pyke, David A.; Pilliod, David S.; Chambers, Jeanne C.; Brooks, Matthew L.; Grace, James

2009-01-01

was positively related to plot- and landscape-level dwarf sagebrush (Artemisia arbuscula, A. nova, A. tripartita) and big sagebrush steppe, and negatively associated with non-native grass and human development. The predicted probability of sage-grouse occupancy at treated plots was low on average (0.07–0.09) and was not significantly different from burned areas that had not been treated. Restoration was more often successful at higher elevation sites with low annual temperatures, high spring precipitation, and high plant diversity. No plots seeded after fire (n=313) met all overstory guidelines for breeding habitats, but approximately 50% met understory guidelines, particularly for perennial grasses. This trend was similar for summer habitat. Ninety-eight percent of treated plots did not meet winter habitat guidelines. Restoration actions in burned areas did not increase the probability of meeting most guideline criteria. The probability of meeting guidelines was influenced by a latitudinal gradient, local climate, and topography. Post-fire seeding treatments in Great Basin sagebrush shrublands generally have not created high quality habitat for sage-grouse. Understory conditions are more likely to be adequate than those of overstory, but in unfavorable climates, establishing forbs and reducing cheatgrass dominance is unlikely. Reestablishing sagebrush cover will require more than 20 years using the restoration methods of the past two decades. Given current fire frequencies and restoration capabilities, protection of landscapes containing a mix of dwarf sagebrush and big sagebrush steppe, minimal human development, and low non-native plant cover may provide the best opportunity for conservation of sage-grouse habitats. Our database of ES&R locations has used the Land Treatment Digital Library to archive data and location information regarding our study (see Pilliod and Welty 2013). This has contributed to two additional studies. One examined the potential spread of

Carbon pool densities and a first estimate of the total carbon pool in the Mongolian forest-steppe.

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Dulamsuren, Choimaa; Klinge, Michael; Degener, Jan; Khishigjargal, Mookhor; Chenlemuge, Tselmeg; Bat-Enerel, Banzragch; Yeruult, Yolk; Saindovdon, Davaadorj; Ganbaatar, Kherlenchimeg; Tsogtbaatar, Jamsran; Leuschner, Christoph; Hauck, Markus

2016-02-01

The boreal forest biome represents one of the most important terrestrial carbon stores, which gave reason to intensive research on carbon stock densities. However, such an analysis does not yet exist for the southernmost Eurosiberian boreal forests in Inner Asia. Most of these forests are located in the Mongolian forest-steppe, which is largely dominated by Larix sibirica. We quantified the carbon stock density and total carbon pool of Mongolia's boreal forests and adjacent grasslands and draw conclusions on possible future change. Mean aboveground carbon stock density in the interior of L. sibirica forests was 66 Mg C ha(-1) , which is in the upper range of values reported from boreal forests and probably due to the comparably long growing season. The density of soil organic carbon (SOC, 108 Mg C ha(-1) ) and total belowground carbon density (149 Mg C ha(-1) ) are at the lower end of the range known from boreal forests, which might be the result of higher soil temperatures and a thinner permafrost layer than in the central and northern boreal forest belt. Land use effects are especially relevant at forest edges, where mean carbon stock density was 188 Mg C ha(-1) , compared with 215 Mg C ha(-1) in the forest interior. Carbon stock density in grasslands was 144 Mg C ha(-1) . Analysis of satellite imagery of the highly fragmented forest area in the forest-steppe zone showed that Mongolia's total boreal forest area is currently 73 818 km(2) , and 22% of this area refers to forest edges (defined as the first 30 m from the edge). The total forest carbon pool of Mongolia was estimated at ~ 1.5-1.7 Pg C, a value which is likely to decrease in future with increasing deforestation and fire frequency, and global warming. © 2015 John Wiley & Sons Ltd.

Vegetation dynamics and dynamic vegetation science

NARCIS (Netherlands)

Van der Maarel, E

1996-01-01

his contribution presents a review of the development of the study of vegetation dynamics since 1979, in the framework of a jubilee meeting on progress in the study of vegetation. However, an exhaustive review is both impossible and unnecessary. It is impossible within the few pages available

Vegetation survey: a new focus for Applied Vegetation Science

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Chytry, M.; Schaminee, J.H.J.; Schwabe, A.

2011-01-01

Vegetation survey is an important research agenda in vegetation science. It defines vegetation types and helps understand differences among them, which is essential for both basic ecological research and applications in biodiversity conservation and environmental monitoring. In this editorial, we

The Genesis of the Urban Culture of the Steppe of the Volga Region and Sociocultural Development of the Region

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Nadezhda V. Dulina

2016-06-01

Full Text Available The article is devoted to the problems of the genesis of socio-historical processes of urban culture of the steppe of the Volga region, is based on historical documents, materials of scientific expeditions conducted in the lower Volga region encyclopedic scientists from the second half of the XVIII century, and the results of archaeological research here settlement sites. Based on the fact that the whole history of mankind is the history of the reference person of its economy, the authors believe that the analysis of the spaces of the modern city must be waged simultaneously in multiple coordinate systems – involving knowledge of scientific disciplines such as history and archeology, sociology, Economics etc. Attention is focused on the events in the Volga steppes of socio-economic and cultural-historical transformation, reflected in the distinctive dynamics of sociocultural development of the medieval (Khazar, the Golden Horde, Russian and modern cities in the region. The authors come to the following conclusions: the city created (and covered by most throughout the centuries (and even millennia by many generations, carry a spatial-temporal characteristics and the variety of creative ideas that make them diverse, aesthetically balanced. The growth of these cities, like all living things, inevitably threatens the time, which naturally destroys some of their historical (and in fact – "root" part to "make room" for new construction. To the relentless dynamism of our era was not able to destroy formed for many generations the idea that is subordinated to the formation and development of each particular city, you should each time from a separate historical parts of the city (or temporal-spatial "fragments" to try to reproduce it in its entirety, as the unity and integrity, while maintaining its inherent identity.

Plant biodiversity patterns on Helan Mountain, China

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Jiang, Yuan; Kang, Muyi; Zhu, Yuan; Xu, Guangcai

2007-09-01

A case study was conducted to mountainous ecosystems in the east side of Helan Mountain, located in the transitional zone between steppe and desert regions of China, aiming to reveal the influences of four environmental factors on features of plant biodiversity—the spatial pattern of vegetation types, and the variation of α- and β-diversities in vegetation and flora. Field surveys on vegetation and flora and on environmental factors were conducted, and those field data were analyzed through CCA (Canonical Correspondence Analysis), and through Shannon-Weiner index for α-diversity and Sørensen index for β-diversity. The preliminary results are: (1) Ranked in terms of their impacts on spatial patterns of plant biodiversity, the four selected environmental factors would be: elevation > location > slope > exposure. (2) The variation of Shannon-Weiner index along the altitudinal gradient is similar to that of species amount within altitudinal belts spanning 200 m each, which suggests a unimodal relationship between the species richness and the environmental condition with regards to altitudinal factors. Both the Shannon-Weiner index and the species richness within each altitudinal belt reach their maximum at elevation range from about 1700 to 2000 m a.s.l. (3) The altitudinal extent with the highest Shannon-Weiner index is identical to the range, where both the deciduous broad-leaved forest, and the temperate evergreen coniferous and deciduous broad-leaved mixed forest distribute. The altitudinal range from 1700 to 2200 m a.s.l. is the sector with both high level of species richness and diversified vegetation types. (4) The variation of β-diversity along the altitude is consistent with the vegetation vertical zones. According to the Sørensen index between each pair of altitudinal belts, the transition of vegetation spectrum from one zone to another, as from the base horizontal zone, the desert steppe, to the first vertical zone, the mountain open forest and