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Sample records for sagebrush ecosystems invaded

  1. 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

  2. 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....

  3. 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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  7. 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....

  8. Restoration handbook for sagebrush steppe ecosystems with emphasis on greater sage-grouse habitat—Part 1. Concepts for understanding and applying restoration

    Science.gov (United States)

    Pyke, David A.; Chambers, Jeanne C.; Pellant, Mike; Knick, Steven T.; Miller, Richard F.; Beck, Jeffrey L.; Doescher, Paul S.; Schupp, Eugene W.; Roundy, Bruce A.; Brunson, Mark; McIver, James D.

    2015-10-26

    Sagebrush steppe ecosystems in the United States currently occur on only about one-half of their historical land area because of changes in land use, urban growth, and degradation of land, including invasions of non-native plants. The existence of many animal species depends on the existence of sagebrush steppe habitat. The greater sage-grouse (Centrocercus urophasianus) is a landscape-dependent bird that requires intact habitat and combinations of sagebrush and perennial grasses to exist. In addition, other sagebrush-obligate animals also have similar requirements and restoration of landscapes for greater sage-grouse also will benefit these animals. Once sagebrush lands are degraded, they may require restoration actions to make those lands viable habitat for supporting sagebrushobligate animals. This restoration handbook is the first in a three-part series on restoration of sagebrush ecosystems. In Part 1, we discuss concepts surrounding landscape and restoration ecology of sagebrush ecosystems and greater sage-grouse that habitat managers and restoration practitioners need to know to make informed decisions regarding where and how to restore specific areas. We will describe the plant dynamics of sagebrush steppe ecosystems and their responses to major disturbances, fire, and defoliation. We will introduce the concepts of ecosystem resilience to disturbances and resistance to invasions of annual grasses within sagebrush steppe. An introduction to soils and ecological site information will provide insights into the specific plants that can be restored in a location. Soil temperature and moisture regimes are described as a tool for determining resilience and resistance and the potential for various restoration actions. Greater sage-grouse are considered landscape birds that require large areas of intact sagebrush steppe; therefore, we describe concepts of landscape ecology that aid our decisions regarding habitat restoration. We provide a brief overview of

  9. The effect of herbaceous species removal, fire and cheatgrass (Bromus tectorum) on soil water availability in sagebrush steppe

    Science.gov (United States)

    Alison Whittaker; Bruce Roundy; Jeanne Chambers; Susan Meyer; Robert Blank; Stanley Kitchen; John Korfmacher

    2008-01-01

    Over the past several decades, cheatgrass (Bromus tectorum) has been continually expanding in the sagebrush steppe ecosystem. There has been very little research that examines why cheatgrass is able to invade these communities. To determine the effects of herbaceous vegetation removal and fire on available water for cheatgrass invasion, as well as...

  10. Restoration handbook for sagebrush steppe ecosystems with emphasis on greater sage-grouse habitat - Part 1

    Science.gov (United States)

    David A. Pyke; Jeanne C. Chambers; Mike Pellant; Steven T. Knick; Richard F. Miller; Jeffrey L. Beck; Paul S. Doescher; Eugene W. Schupp; Bruce A. Roundy; Mark Brunson; James D. McIver

    2015-01-01

    Sagebrush steppe ecosystems in the United States currently occur on only about one-half of their historical land area because of changes in land use, urban growth, and degradation of land, including invasions of non-native plants. The existence of many animal species depends on the existence of sagebrush steppe habitat. The greater sage-grouse (Centrocercus...

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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...

  14. 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...

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

    Science.gov (United States)

    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

  16. 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.

  17. Restoration handbook for sagebrush steppe ecosystems with emphasis on greater sage-grouse habitat - Part 3: Site level restoration decisions

    Science.gov (United States)

    David A. Pyke; Jeanne C. Chambers; Mike Pellant; Richard F. Miller; Jeffrey L. Beck; Paul S. Doescher; Bruce A. Roundy; Eugene W. Schupp; Steven T. Knick; Mark Brunson; James D. McIver

    2017-01-01

    Sagebrush steppe ecosystems in the United States currently (2016) occur on only about one-half of their historical land area because of changes in land use, urban growth, and degradation of land, including invasions of non-native plants. The existence of many animal species depends on the existence of sagebrush steppe habitat. The greater sage-grouse (Centrocercus...

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

    Science.gov (United States)

    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

  19. 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...

  20. Mercury distribution in two Sierran forest and one desert sagebrush steppe ecosystems and the effects of fire

    International Nuclear Information System (INIS)

    Engle, Mark A.; Sexauer Gustin, Mae; Johnson, Dale W.; Murphy, James F.; Miller, Wally W.; Walker, Roger F.; Wright, Joan; Markee, Melissa

    2006-01-01

    Mercury (Hg) concentration, reservoir mass, and Hg reservoir size were determined for vegetation components, litter, and mineral soil for two Sierran forest sites and one desert sagebrush steppe site. Mercury was found to be held primarily in the mineral soil (maximum depth of 60 to 100 cm), which contained more than 90% of the total ecosystem reservoir. However, Hg in foliage, bark, and litter plays a more dominant role in Hg cycling than the mineral soil. Mercury partitioning into ecosystem components at the Sierran forest sites was similar to that observed for other US forest sites. Vegetation and litter Hg reservoirs were significantly smaller in the sagebrush steppe system because of lower biomass. Data collected from these ecosystems after wildfire and prescribed burns showed a significant decrease in the Hg pool from certain reservoirs. No loss from mineral soil was observed for the study areas but data from fire severity points suggested that Hg in the upper few millimeters of surface soil may be volatilized due to exposure to elevated temperatures. Comparison of data from burned and unburned plots suggested that the only significant source of atmospheric Hg from the prescribed burn was combustion of litter. Differences in unburned versus burned Hg reservoirs at the forest wildfire site demonstrated that drastic reduction in the litter and above ground live biomass Hg reservoirs after burning had occurred. Sagebrush and litter were absent in the burned plots after a wildfire suggesting that both reservoirs were released during the fire. Mercury emissions due to fire from the forest prescribed burn, forest wildfire, and sagebrush steppe wildfire sites were roughly estimated at 2.0 to 5.1, 2.2 to 4.9, and 0.36 ± 0.13 g ha -1 , respectively, with litter and vegetation being the most important sources

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

    Science.gov (United States)

    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...

  2. 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

    Science.gov (United States)

    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.

  3. 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...

  4. Abiotic and biotic influences on Bromus tectoreum invasion and Artemisia tridentata recovery after fire

    Science.gov (United States)

    Lea Condon; Peter J. Weisberg; Jeanne C. Chambers

    2011-01-01

    Native sagebrush ecosystems in the Great Basin (western USA) are often invaded following fire by exotic Bromus tectorum (cheatgrass), a highly flammable annual grass. Once B. tectorum is established, higher fire frequencies can lead to local extirpation of Artemisia tridentata ssp. vaseyana (mountain big sagebrush) and have cascading effects on sagebrush ecosystems and...

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

    Science.gov (United States)

    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

  6. Multiscale sagebrush rangeland habitat modeling in the Gunnison Basin of Colorado

    Science.gov (United States)

    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

  7. 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

  8. 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

  9. 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....

  10. 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...

  11. Using Unmanned Aerial Vehicles to Assess Vegetative Cover and Identify Biotic Resources in Sagebrush Steppe Ecosystems: Preliminary Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Robert P. Breckenridge

    2006-04-01

    The Idaho National Laboratory (INL), in conjunction with the University of Idaho, is evaluating novel approaches for using unmanned aerial vehicles (UAVs) as a quicker and safer method for monitoring biotic resources. Evaluating vegetative cover is an important factor in understanding the sustainability of many ecosystems. In assessing vegetative cover, methods that improve accuracy and cost efficiency could revolutionize how biotic resources are monitored on western federal lands. Sagebrush steppe ecosystems provide important habitat for a variety of species, some of which are important indicator species (e.g., sage grouse). Improved methods are needed to support monitoring these habitats because there are not enough resource specialists or funds available for comprehensive ground evaluation of these ecosystems. In this project, two types of UAV platforms (fixed wing and helicopter) were used to collect still-frame imagery to assess cover in sagebrush steppe ecosystems. This paper discusses the process for collecting and analyzing imagery from the UAVs to (1) estimate total percent cover, (2) estimate percent cover for six different types of vegetation, and (3) locate sage grouse based on representative decoys. The field plots were located on the INL site west of Idaho Falls, Idaho, in areas with varying amounts and types of vegetative cover. A software program called SamplePoint developed by the U.S. Department of Agriculture, Agricultural Research Service was used to evaluate the imagery for percent cover for the six vegetation types (bare ground, litter, shrubs, dead shrubs, grasses, and forbs). Results were compared against standard field measurements to assess accuracy.

  12. Effectiveness of prescribed fire to re-establish sagebrush vegetation and ecohydrologic function on woodland-encroached sagebrush steppe, Great Basin, USA

    Science.gov (United States)

    Williams, C. J.; Pierson, F. B.; Kormos, P.; Al-Hamdan, O. Z.; Nouwakpo, S.; Weltz, M.; Vega, S.; Lindsay, K.

    2017-12-01

    Range expansion of pinyon (Pinus spp.) and juniper (Juniperus spp.) conifers into sagebrush steppe (Artemisia spp.) communities has imperiled a vast domain in the western US. Encroachment of sagebrush ecosystems by pinyon and juniper conifers has negative ramifications to ecosystem structure and function and delivery of goods and services. Scientists, land management agencies, and private land owners throughout the western US are challenged with selecting from a suite of options to reduce pinyon and juniper woody fuels and re-establish sagebrush steppe structure and function. This study evaluated the effectiveness of prescribed fire to re-establish sagebrush vegetation and ecohydrologic function over a 9 yr period. Nine years post-fire hydrologic and erosion responses reflect the combination of pre-fire site conditions, perennial grass recruitment, delayed litter cover, and inherent site characteristics. Burning initially increased bare ground, runoff, and erosion for well-vegetated areas underneath tree and shrub canopies, but had minimal impact on hydrology and erosion for degraded interspaces between plants. The degraded interspaces were primarily bare ground and exhibited high runoff and erosion rates prior to burning. Initial fire effects persisted for two years, but increased productivity of grasses improved hydrologic function of interspaces over the full 9 yr period. At the hillslope scale, grass recruitment in the intercanopy between trees reduced runoff from rainsplash, sheetflow, and concentrated overland flow at one site, but did not reduce the high levels of runoff and erosion from a more degraded site. In areas formerly occupied by trees (tree zones), burning increased invasive annual grass cover due to fire removal of limited native perennial plants and competition for resources. The invasive annual grass cover had no net effect on runoff and erosion from tree zones however. Runoff and erosion increased in tree zones at the more degraded site due to

  13. 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.

  14. 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...

  15. Vegetation responses to sagebrush-reduction treatments measured by satellites

    Science.gov (United States)

    Johnston, Aaron; Beever, Erik; Merkle, Jerod A.; Chong, Geneva W.

    2018-01-01

    Time series of vegetative indices derived from satellite imagery constitute tools to measure ecological effects of natural and management-induced disturbances to ecosystems. Over the past century, sagebrush-reduction treatments have been applied widely throughout western North America to increase herbaceous vegetation for livestock and wildlife. We used indices from satellite imagery to 1) quantify effects of prescribed-fire, herbicide, and mechanical treatments on vegetative cover, productivity, and phenology, and 2) describe how vegetation changed over time following these treatments. We hypothesized that treatments would increase herbaceous cover and accordingly shift phenologies towards those typical of grass-dominated systems. We expected prescribed burns would lead to the greatest and most-prolonged effects on vegetative cover and phenology, followed by herbicide and mechanical treatments. Treatments appeared to increase herbaceous cover and productivity, which coincided with signs of earlier senescence − signals expected of grass-dominated systems, relative to sagebrush-dominated systems. Spatial heterogeneity for most phenometrics was lower in treated areas relative to controls, which suggested treatment-induced homogenization of vegetative communities. Phenometrics that explain spring migrations of ungulates mostly were unaffected by sagebrush treatments. Fire had the strongest effect on vegetative cover, and yielded the least evidence for sagebrush recovery. Overall, treatment effects were small relative to those reported from field-based studies for reasons most likely related to sagebrush recovery, treatment specification, and untreated patches within mosaicked treatment applications. Treatment effects were also small relative to inter-annual variation in phenology and productivity that was explained by temperature, snowpack, and growing-season precipitation. Our results indicated that cumulative NDVI, late-season phenometrics, and spatial

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

    Science.gov (United States)

    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

  17. 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

  18. Mapping cryptic invaders and invisability of tropical forest ecosystems: Chromolaena odorata in Nepal

    OpenAIRE

    Joshi, C.

    2006-01-01

    For centuries, people continuously increased the rate of biological invasions and there is no sign of slowing down. From the depth of the Ocean to the crest of Himalayas, they are occupying pristine and semi-natural ecosystems at an alarming rate, threatening human, animal, plant as well as ecosystem health. Efforts to avoid or eradicate them are not achievable except for very few cases. Currently, therefore, their management aims at controlling invaders and mitigating their impact rather tha...

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

    Science.gov (United States)

    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...

  20. 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

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

    Science.gov (United States)

    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

  2. Woody fuels reduction in Wyoming big sagebrush communities

    Science.gov (United States)

    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...

  3. Bumble bee (Hymenoptera: Apidae) community structure on two sagebrush steppe sites in southern Idaho

    Science.gov (United States)

    Stephen P. Cook; Sara M. Birch; Frank W. Merickel; Carrie Caselton Lowe; Deborah Page-Dumroese

    2011-01-01

    Although sagebrush, Artemisia spp., does not require an insect pollinator, there are several native species of bumble bees, Bombus spp. (Hymenoptera: Apidae), that are present in sagebrush steppe ecosystems where they act as pollinators for various forbs and shrubs. These native pollinators contribute to plant productivity and reproduction. We captured 12 species of...

  4. 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...

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

    Science.gov (United States)

    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...

  6. 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

  7. Ecological influence and pathways of land use in sagebrush

    Science.gov (United States)

    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

  8. The role of symbiotic nitrogen fixation in nitrogen availability, competition and plant invasion into the sagebrush steppe

    Science.gov (United States)

    Erin M. Goergen

    2009-01-01

    In the semi-arid sagebrush steppe of the Northeastern Sierra Nevada, resources are both spatially and temporally variable, arguably making resource availability a primary factor determining invasion success. N fixing plant species, primarily native legumes, are often relatively abundant in sagebrush steppe and can contribute to ecosystem nitrogen budgets. ...

  9. 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.

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

    Science.gov (United States)

    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

  11. Ecosystem impacts of exotic annual invaders in the Genus Bromus

    Science.gov (United States)

    Germino, Matthew J.; Belnap, Jayne; Stark, John M.; Allen, Edith B.; Rau, Benjamin M.

    2016-01-01

    An understanding of the impacts of exotic plant species on ecosystems is necessary to justify and guide efforts to limit their spread, restore natives, and plan for conservation. Invasive annual grasses such as Bromus tectorum, B. rubens, B. hordeaceus, and B. diandrus (hereafter collectively referred to as Bromus) transform the structure and function of ecosystems they dominate. Experiments that prove cause-and-effect impacts of Bromus are rare, yet inferences can be gleaned from the combination of Bromus-ecosystem associations, ecosystem condition before/after invasion, and an understanding of underlying mechanisms. Bromus typically establishes in bare soil patches and can eventually replace perennials such as woody species or bunchgrasses, creating a homogeneous annual cover. Plant productivity and cover are less stable across seasons and years when Bromus dominates, due to a greater response to annual climate variability. Bromus’ “flash” of growth followed by senescence early in the growing season, combined with shallow rooting and annual habit, may lead to incomplete use of deep soil water, reduced C sequestration, and accelerated nutrient cycling. Litter produced by Bromus alters nearly all aspects of ecosystems and notably increases wildfire occurrence. Where Bromus has become dominant, it can decrease soil stability by rendering soils bare for months following fire or episodic, pathogen-induced stand failure. Bromus-invaded communities have lower species diversity, and associated species tend to be generalists adapted to unstable and variable habitats. Changes in litter, fire, and soil properties appear to feedback to reinforce Bromus’ dominance in a pattern that portends desertification.

  12. 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.

  13. Remote sensing of sagebrush canopy nitrogen

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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.

  16. 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...

  17. Nitrogen limitation, 15N tracer retention, and growth response in intact and Bromus tectorum-invaded Artemisia tridentata ssp. wyomingensis communities

    Science.gov (United States)

    Witwicki, Dana L.; Doescher, Paul S.; Pyke, David A.; DeCrappeo, Nicole M.; Perakis, Steven S.

    2012-01-01

    Annual grass invasion into shrub-dominated ecosystems is associated with changes in nutrient cycling that may alter nitrogen (N) limitation and retention. Carbon (C) applications that reduce plant-available N have been suggested to give native perennial vegetation a competitive advantage over exotic annual grasses, but plant community and N retention responses to C addition remain poorly understood in these ecosystems. The main objectives of this study were to (1) evaluate the degree of N limitation of plant biomass in intact versus B. tectorum-invaded sagebrush communities, (2) determine if plant N limitation patterns are reflected in the strength of tracer 15N retention over two growing seasons, and (3) assess if the strength of plant N limitation predicts the efficacy of carbon additions intended to reduce soil N availability and plant growth. Labile C additions reduced biomass of exotic annual species; however, growth of native A. tridentata shrubs also declined. Exotic annual and native perennial plant communities had divergent responses to added N, with B. tectorum displaying greater ability to use added N to rapidly increase aboveground biomass, and native perennials increasing their tissue N concentration but showing little growth response. Few differences in N pools between the annual and native communities were detected. In contrast to expectations, however, more 15N was retained over two growing seasons in the invaded annual grass than in the native shrub community. Our data suggest that N cycling in converted exotic annual grasslands of the northern Intermountain West, USA, may retain N more strongly than previously thought.

  18. 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.

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

    Science.gov (United States)

    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,...

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

    Science.gov (United States)

    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.

  1. Evaluating greater sage-grouse seasonal space use relative to leks: Implications for surface use designations in sagebrush ecosystems

    Science.gov (United States)

    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

  2. The potential of novel native plant materials for the restoration of novel ecosystems

    Directory of Open Access Journals (Sweden)

    T.A. Jones

    2015-05-01

    Full Text Available Abstract Extensive ecological change has been sustained by many dryland ecosystems throughout the world, resulting in conversion to so-called novel ecosystems. It is within such ecological contexts that native plant materials destined for ecological applications must be able to function. In the Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis [Beetle & A.M. Young] S.L. Welsh ecosystems of the Intermountain West, for example, novel ecosystem structure and functioning are pervasive. Invasive species, particularly annual grasses, fuel repeated wildfires that drive previously stable ecosystem states across thresholds to less desirable states that are highly recalcitrant to restoration efforts. Structural changes include reductions of native flora, damage to biological soil crusts, and alterations to soil microbiota. Functional changes include altered hydrologic and nutrient cycling, leading to permanent losses of soil organic matter and nitrogen that favor the invaders. We argue that there is an important place in restoration for plant materials that are novel and/or non-local that have been developed to be more effective in the novel ecosystems for which they are intended, thus qualifying them as “ecologically appropriate.” Such plant materials may be considered as an alternative to natural/local “genetically appropriate” plant materials, which are sometimes deemed best adapted due to vetting by historical evolutionary processes.

  3. Using Unmanned Aerial Vehicles to Assess Vegetative Cover in Sagebrush Steppe Ecosytstems

    Energy Technology Data Exchange (ETDEWEB)

    Robert P. Breckenridge

    2005-09-01

    The Idaho National Laboratory (INL), in conjunction with the University of Idaho, is evaluating novel approaches for using unmanned aerial vehicles (UAVs) as a quicker and safer method for monitoring biotic resources. Evaluating vegetative cover is an important factor in understanding the sustainability of many ecosystems. In assessing vegetative cover, methods that improve accuracy and cost efficiency could revolutionize how biotic resources are monitored on western federal lands. Sagebrush steppe ecosystems provide important habitat for a variety of species, some of which are important indicator species (e.g., sage grouse). Improved methods are needed to support monitoring these habitats because there are not enough resource specialists or funds available for comprehensive ground evaluation of these ecosystems. In this project, two types of UAV platforms (fixed wing and helicopter) were used to collect still-frame imagery to assess cover in sagebrush steppe ecosystems. This paper discusses the process for collecting and analyzing imagery from the UAVs to (1) estimate total percent cover, (2) estimate percent cover for six different types of vegetation, and (3) locate sage grouse based on representative decoys. The field plots were located on the INL site west of Idaho Falls, Idaho, in areas with varying amounts and types of vegetative cover. A software program called SamplePoint developed by the U.S. Department of Agriculture, Agricultural Research Service (USDA-ARS) was used to evaluate the imagery for percent cover for the six vegetation types (bare ground, litter, shrubs, dead shrubs, grasses, and forbs). Results were compared against standard field measurements to assess accuracy.

  4. 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.

  5. 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

  6. Natural regeneration processes in big sagebrush (Artemisia tridentata)

    Science.gov (United States)

    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

  7. 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.

  8. Restoration of mountain big sagebrush steppe following prescribed burning to control western juniper.

    Science.gov (United States)

    Davies, K W; Bates, J D; Madsen, M D; Nafus, A M

    2014-05-01

    Western juniper (Juniperus occidentalis ssp. occidentalis Hook) encroachment into mountain big sagebrush (Artemisia tridentata spp. vaseyana (Rydb.) Beetle) steppe has reduced livestock forage production, increased erosion risk, and degraded sagebrush-associated wildlife habitat. Western juniper has been successfully controlled with partial cutting followed by prescribed burning the next fall, but the herbaceous understory and sagebrush may be slow to recover. We evaluated the effectiveness of seeding perennial herbaceous vegetation and sagebrush at five sites where juniper was controlled by partially cutting and prescribed burning. Treatments tested at each site included an unseeded control, herbaceous seed mix (aerially seeded), and the herbaceous seed mix plus sagebrush seed. In the third year post-treatment, perennial grass cover and density were twice as high in plots receiving the herbaceous seed mix compared to the control plots. Sagebrush cover and density in the sagebrush seeded plots were between 74- and 290-fold and 62- and 155-fold greater than the other treatments. By the third year after treatment, sagebrush cover was as high as 12 % in the sagebrush seeded plots and between 0 % and 0.4 % where it was not seeded. These results indicate that aerial seeding perennial herbaceous vegetation can accelerate the recovery of perennial grasses which likely stabilize the site. Our results also suggest that seeding mountain big sagebrush after prescribed burning encroaching juniper can rapidly recover sagebrush cover and density. In areas where sagebrush habitat is limited, seeding sagebrush after juniper control may increase sagebrush habitat and decrease the risks to sagebrush-associated species.

  9. The unseen invaders

    DEFF Research Database (Denmark)

    Craven, Dylan; Thakur, Madhav P.; Cameron, Erin

    2017-01-01

    earthworms on plant diversity and community composition in North American forests. We conducted a meta-analysis using a total of 645 observations to quantify mean effect sizes of associations between introduced earthworm communities and plant diversity, cover of plant functional groups, and cover of native...... to the abiotic conditions of earthworm-invaded forests. Further, our study provides evidence that introduced earthworms are associated with declines in plant diversity in North American forests. Changing plant functional composition in these forests may have long-lasting effects on ecosystem functioning....

  10. 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).

  11. Land use and habitat conditions across the southwestern Wyoming sagebrush steppe: development impacts, management effectiveness and the distribution of invasive plants

    Science.gov (United States)

    Manier, Daniel J.; Aldridge, Cameron L.; Anderson, Patrick; Chong, Geneva; Homer, Collin G.; O'Donnell, Michael S.; Schell, Spencer

    2011-01-01

    For the past several years, USGS has taken a multi-faceted approach to investigating the condition and trends in sagebrush steppe ecosystems. This recent effort builds upon decades of work in semi-arid ecosystems providing a specific, applied focus on the cumulative impacts of expanding human activities across these landscapes. Here, we discuss several on-going projects contributing to these efforts: (1) mapping and monitoring the distribution and condition of shrub steppe communities with local detail at a regional scale, (2) assessing the relationships between specific, land-use features (for example, roads, transmission lines, industrial pads) and invasive plants, including their potential (environmentally defined) distribution across the region, and (3) monitoring the effects of habitat treatments on the ecosystem, including wildlife use and invasive plant abundance. This research is focused on the northern sagebrush steppe, primarily in Wyoming, but also extending into Montana, Colorado, Utah and Idaho. The study area includes a range of sagebrush types (including, Artemisia tridentata ssp. tridentata, Artemisia tridentata ssp. wyomingensis, Artemisia tridentata ssp. vaseyana, Artemisia nova) and other semi-arid shrubland types (for example, Sarcobatus vermiculatus, Atriplex confertifolia, Atriplex gardneri), impacted by extensive interface between steppe ecosystems and industrial energy activities resulting in a revealing multiple-variable analysis. We use a combination of remote sensing (AWiFS (1 Any reference to platforms, data sources, equipment, software, patented or trade-marked methods is for information purposes only. It does not represent endorsement of the U.S.D.I., U.S.G.S. or the authors), Landsat and Quickbird platforms), Geographic Information System (GIS) design and data management, and field-based, replicated sampling to generate multiple scales of data representing the distribution of shrub communities for the habitat inventory. Invasive plant

  12. 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.

  13. Plant litter chemistry alters the content and composition of organic carbon associated with soil mineral and aggregate fractions in invaded ecosystems.

    Science.gov (United States)

    Tamura, Mioko; Suseela, Vidya; Simpson, Myrna; Powell, Brian; Tharayil, Nishanth

    2017-10-01

    Through the input of disproportionate quantities of chemically distinct litter, invasive plants may potentially influence the fate of organic matter associated with soil mineral and aggregate fractions in some of the ecosystems they invade. Although context dependent, these native ecosystems subjected to prolonged invasion by exotic plants may be instrumental in distinguishing the role of plant-microbe-mineral interactions from the broader edaphic and climatic influences on the formation of soil organic matter (SOM). We hypothesized that the soils subjected to prolonged invasion by an exotic plant that input recalcitrant litter (Japanese knotweed, Polygonum cuspidatum) would have a greater proportion of plant-derived carbon (C) in the aggregate fractions, as compared with that in adjacent soil inhabited by native vegetation that input labile litter, whereas the soils under an invader that input labile litter (kudzu, Pueraria lobata) would have a greater proportion of microbial-derived C in the silt-clay fraction, as compared with that in adjacent soils that receive recalcitrant litter. At the knotweed site, the higher C content in soils under P. cuspidatum, compared with noninvaded soils inhabited by grasses and forbs, was limited to the macroaggregate fraction, which was abundant in plant biomarkers. The noninvaded soils at this site had a higher abundance of lignins in mineral and microaggregate fractions and suberin in the macroaggregate fraction, partly because of the greater root density of the native species, which might have had an overriding influence on the chemistry of the above-ground litter input. At the kudzu site, soils under P. lobata had lower C content across all size fractions at a 0-5 cm soil depth despite receiving similar amounts of Pinus litter. Contrary to our prediction, the noninvaded soils receiving recalcitrant Pinus litter had a similar abundance of plant biomarkers across both mineral and aggregate fractions, potentially because of

  14. 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 (...

  15. 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

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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...

  18. Investigation of Darwin’s naturalization hypothesis in invaded macrophyte communities

    Science.gov (United States)

    Although native macrophytes are beneficial in aquatic ecosystems, invasive macrophytes can cause significant ecological and economic harm. Numerous studies have attributed invasiveness to species’ characteristics, whereas others attribute invasion to biotic and abiotic characteristics of the invaded...

  19. Global Invader Impact Network (GIIN): toward standardized evaluation of the ecological impacts of invasive plants.

    Science.gov (United States)

    Barney, Jacob N; Tekiela, Daniel R; Barrios-Garcia, Maria Noelia; Dimarco, Romina D; Hufbauer, Ruth A; Leipzig-Scott, Peter; Nuñez, Martin A; Pauchard, Aníbal; Pyšek, Petr; Vítková, Michaela; Maxwell, Bruce D

    2015-07-01

    Terrestrial invasive plants are a global problem and are becoming ubiquitous components of most ecosystems. They are implicated in altering disturbance regimes, reducing biodiversity, and changing ecosystem function, sometimes in profound and irreversible ways. However, the ecological impacts of most invasive plants have not been studied experimentally, and most research to date focuses on few types of impacts, which can vary greatly among studies. Thus, our knowledge of existing ecological impacts ascribed to invasive plants is surprisingly limited in both breadth and depth. Our aim was to propose a standard methodology for quantifying baseline ecological impact that, in theory, is scalable to any terrestrial plant invader (e.g., annual grasses to trees) and any invaded system (e.g., grassland to forest). The Global Invader Impact Network (GIIN) is a coordinated distributed experiment composed of an observational and manipulative methodology. The protocol consists of a series of plots located in (1) an invaded area; (2) an adjacent removal treatment within the invaded area; and (3) a spatially separate uninvaded area thought to be similar to pre-invasion conditions of the invaded area. A standardized and inexpensive suite of community, soil, and ecosystem metrics are collected allowing broad comparisons among measurements, populations, and species. The method allows for one-time comparisons and for long-term monitoring enabling one to derive information about change due to invasion over time. Invader removal plots will also allow for quantification of legacy effects and their return rates, which will be monitored for several years. GIIN uses a nested hierarchical scale approach encompassing multiple sites, regions, and continents. Currently, GIIN has network members in six countries, with new members encouraged. To date, study species include representatives of annual and perennial grasses; annual and perennial forbs; shrubs; and trees. The goal of the GIIN

  20. 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...

  1. 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...

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

    Science.gov (United States)

    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.

  3. 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...

  4. A synopsis of short-term response to alternative restoration treatments in sagebrush-steppe: the SageSTEP project

    Science.gov (United States)

    McIver, James; Brunson, Mark; Bunting, Steve; Chambers, Jeanne; Doescher, Paul; Grace, James; Hulet, April; Johnson, Dale; Knick, Steven T.; Miller, Richard; Pellant, Mike; Pierson, Fred; Pyke, David; Rau, Benjamin; Rollins, Kim; Roundy, Bruce; Schupp, Eugene; Tausch, Robin; Williams, Jason

    2014-01-01

    The Sagebrush Steppe Treatment Evaluation Project (SageSTEP) is an integrated long-term study that evaluates ecological effects of alternative treatments designed to reduce woody fuels and to stimulate the herbaceous understory of sagebrush steppe communities of the Intermountain West. This synopsis summarizes results through 3 yr posttreatment. Woody vegetation reduction by prescribed fire, mechanical treatments, or herbicides initiated a cascade of effects, beginning with increased availability of nitrogen and soil water, followed by increased growth of herbaceous vegetation. Response of butterflies and magnitudes of runoff and erosion closely followed herbaceous vegetation recovery. Effects on shrubs, biological soil crust, tree cover, surface woody fuel loads, and sagebrush-obligate bird communities will take longer to be fully expressed. In the short term, cool wet sites were more resilient than warm dry sites, and resistance was mostly dependent on pretreatment herbaceous cover. At least 10 yr of posttreatment time will likely be necessary to determine outcomes for most sites. Mechanical treatments did not serve as surrogates for prescribed fire in how each influenced the fuel bed, the soil, erosion, and sage-obligate bird communities. Woody vegetation reduction by any means resulted in increased availability of soil water, higher herbaceous cover, and greater butterfly numbers. We identified several trade-offs (desirable outcomes for some variables, undesirable for others), involving most components of the study system. Trade-offs are inevitable when managing complex natural systems, and they underline the importance of asking questions about the whole system when developing management objectives. Substantial spatial and temporal heterogeneity in sagebrush steppe ecosystems emphasizes the point that there will rarely be a “recipe” for choosing management actions on any specific area. Use of a consistent evaluation process linked to monitoring may be the

  5. Legacy effects of no-analogue disturbances alter plant community diversity and composition in semi-arid sagebrush steppe

    Science.gov (United States)

    Ripplinger, Julie; Franklin, Janet; Edwards, Thomas C.

    2015-01-01

    Questions(i) What role does the type of managed disturbance play in structuring sagebrush steppe plant communities? (ii) How does the composition of post-disturbance plant communities change with time since disturbance? (iii) Does plant community diversity change over time following managed disturbance?LocationField study within the sagebrush steppe ecosystem. Rich County, Utah, USA.MethodsWe developed a chronosequence spanning up to 50 yrs post-treatment to study sagebrush steppe vegetation dynamics. Direct ordination was used to examine plant community composition by managed disturbance type and time since disturbance, and factorial analysis of covariance was used to examine diversity dynamics following disturbance. Indicator species values were calculated in order to identify characteristic species for each disturbance type.ResultsPlant communities experienced a shift toward distinct community composition for each of the three managed disturbance types, and gave no indication of returning to untreated community composition or diversity. Small post-disturbance increases in the number of non-native grass species were observed in the treatments relative to reference, with native forb species making the largest contribution to altered composition. On fire- and chemically-treated sites the proportional native forb species richness increased over time since disturbance, while the proportional contribution of non-native forbs to total species richness decreased. For all three treatment types, native grasses contributed less on average to total richness than on reference sites, while non-native grasses made up a higher proportion of total richness.ConclusionsCommon shrubland management techniques have legacy effects on the composition and diversity of sagebrush steppe plant communities, and no-analogue disturbances, such as chemical or mechanical treatments, have more pronounced legacy effects than treatments similar to natural disturbance regimes (fire). This study

  6. 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...

  7. Alien roadside species more easily invade alpine than lowland plant communities in a subarctic mountain ecosystem.

    Directory of Open Access Journals (Sweden)

    Jonas J Lembrechts

    Full Text Available Effects of roads on plant communities are not well known in cold-climate mountain ecosystems, where road building and development are expected to increase in future decades. Knowledge of the sensitivity of mountain plant communities to disturbance by roads is however important for future conservation purposes. We investigate the effects of roads on species richness and composition, including the plant strategies that are most affected, along three elevational gradients in a subarctic mountain ecosystem. We also examine whether mountain roads promote the introduction and invasion of alien plant species from the lowlands to the alpine zone. Observations of plant community composition were made together with abiotic, biotic and anthropogenic factors in 60 T-shaped transects. Alpine plant communities reacted differently to road disturbances than their lowland counterparts. On high elevations, the roadside species composition was more similar to that of the local natural communities. Less competitive and ruderal species were present at high compared with lower elevation roadsides. While the effects of roads thus seem to be mitigated in the alpine environment for plant species in general, mountain plant communities are more invasible than lowland communities. More precisely, relatively more alien species present in the roadside were found to invade into the surrounding natural community at high compared to low elevations. We conclude that effects of roads and introduction of alien species in lowlands cannot simply be extrapolated to the alpine and subarctic environment.

  8. Alien roadside species more easily invade alpine than lowland plant communities in a subarctic mountain ecosystem.

    Science.gov (United States)

    Lembrechts, Jonas J; Milbau, Ann; Nijs, Ivan

    2014-01-01

    Effects of roads on plant communities are not well known in cold-climate mountain ecosystems, where road building and development are expected to increase in future decades. Knowledge of the sensitivity of mountain plant communities to disturbance by roads is however important for future conservation purposes. We investigate the effects of roads on species richness and composition, including the plant strategies that are most affected, along three elevational gradients in a subarctic mountain ecosystem. We also examine whether mountain roads promote the introduction and invasion of alien plant species from the lowlands to the alpine zone. Observations of plant community composition were made together with abiotic, biotic and anthropogenic factors in 60 T-shaped transects. Alpine plant communities reacted differently to road disturbances than their lowland counterparts. On high elevations, the roadside species composition was more similar to that of the local natural communities. Less competitive and ruderal species were present at high compared with lower elevation roadsides. While the effects of roads thus seem to be mitigated in the alpine environment for plant species in general, mountain plant communities are more invasible than lowland communities. More precisely, relatively more alien species present in the roadside were found to invade into the surrounding natural community at high compared to low elevations. We conclude that effects of roads and introduction of alien species in lowlands cannot simply be extrapolated to the alpine and subarctic environment.

  9. Structural and functional changes of soft-bottom ecosystems in northern fjords invaded by the red king crab (Paralithodes camtschaticus)

    Science.gov (United States)

    Oug, Eivind; Sundet, Jan H.; Cochrane, Sabine K. J.

    2018-04-01

    The red king crab invaded Norwegian coastal waters in the early 1990s after having been introduced from the northern Pacific to the Russian Barents Sea coast. The crab stock increased rapidly in NE northern Norway in the latter half of the 1990s, and since 2002 there has been a commercial fishery in the eastern invaded areas. The crab is an active predator on benthic fauna especially feeding in deep soft-bottom environments. The present study is a follow-up of previous studies (2007-09) to assess the effects of the king crab predation on soft bottom species composition, ecological functioning and sediment quality. Macroinfauna (> 1 mm) was investigated in three fjord areas in the Varanger region with low, moderate and very high crab abundances, respectively. Compared with data from 1994, most benthic species were markedly reduced in abundance, in particular non-moving burrowing and tube-dwelling polychaetes, bivalves and echinoderms. However, a few species appeared to recover from 2007-09 to 2012. Changes in ecological functioning were assessed using 'biological traits analysis (BTA)'. Following the crab invasion there was a relative reduction of suspension and surface deposit feeding species, an increase in mobile and predatory organisms and an increase in those with planktotrophic larval development. From low to high crab abundances functioning changed from tube-building, deep deposit feeding and fairly large size to free-living, shallow burrowing and rather small size. With regard to sediment reworking, downward and upward conveyors were reduced whereas surficial modifiers increased. The changes imply that sediment biomixing and bioirrigation were reduced leading to a degraded sedimentary environment. It is suggested that establishing relationships between ecosystem functioning and crab abundances may form the basis for estimating ecological costs of the crab invasion. Such knowledge is important for managing the crab in the Barents Sea area being both a non

  10. 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

  11. 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...

  12. Competitive interactions between co-occurring invaders: identifying asymmetries between two invasive crayfish species

    NARCIS (Netherlands)

    Hudina, S.; Galic, N.G.; Roessink, I.; Hock, K.

    2011-01-01

    Ecosystems today increasingly suffer invasions by multiple invasive species. Complex interactions between invasive species can have different fitness implications for each invader, which can in turn determine the future progression of their invasions and result in differential impacts on native

  13. Characterization of shrubland ecosystem components as continuous fields in the northwest United States

    Science.gov (United States)

    Xian, George Z.; Homer, Collin G.; Rigge, Matthew B.; Shi, Hua; Meyer, Debbie

    2015-01-01

    Accurate and consistent estimates of shrubland ecosystem components are crucial to a better understanding of ecosystem conditions in arid and semiarid lands. An innovative approach was developed by integrating multiple sources of information to quantify shrubland components as continuous field products within the National Land Cover Database (NLCD). The approach consists of several procedures including field sample collections, high-resolution mapping of shrubland components using WorldView-2 imagery and regression tree models, Landsat 8 radiometric balancing and phenological mosaicking, medium resolution estimates of shrubland components following different climate zones using Landsat 8 phenological mosaics and regression tree models, and product validation. Fractional covers of nine shrubland components were estimated: annual herbaceous, bare ground, big sagebrush, herbaceous, litter, sagebrush, shrub, sagebrush height, and shrub height. Our study area included the footprint of six Landsat 8 scenes in the northwestern United States. Results show that most components have relatively significant correlations with validation data, have small normalized root mean square errors, and correspond well with expected ecological gradients. While some uncertainties remain with height estimates, the model formulated in this study provides a cross-validated, unbiased, and cost effective approach to quantify shrubland components at a regional scale and advances knowledge of horizontal and vertical variability of these components.

  14. Life History Variation in Invading Applesnails (Pomacea canaliculata) May Pose Ecological Threats to Wetlands

    Science.gov (United States)

    Marfurt, R. K.; Boland, B. B.; Burks, R. L.

    2005-05-01

    In native habitats, channeled applesnails (Pomacea canaliculata) graze periphyton. However, casual observations from introduced populations suggest these invaders show variation in feeding ecology, predator response and life history strategies. Attempts to predict this consumer influence on ecosystem function suffer from a lack of basic data. We tested how salinity affected snail mortality. Both adults and hatchlings tolerated salinity levels up to 8 ppt. Adult feeding on lettuce increased significantly at 8 ppt compared to 0 ppt (p = 0.002), while hatchling consumption of algae did not vary (p = 0.284). To see how these consumers responded to predators from the invaded ecosystem, we tested behavioural responses to predatory cues from fish, turtles, crayfish and adult applesnails. Results indicated that fish and crayfish prompted similar predator-avoidance behaviors in hatchlings (p's 0.05) between native (ramshorn) and exotic applesnails, whereas adult fish consumed more applesnails (x2, p < 0.001). Our current efforts focus on examining if predator presence or macrophyte choice alters applesnail feeding rates. Research providing insight into the basic ecology of applesnails can foster management efforts at the ecosystem scale.

  15. 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.

  16. Parasites of the raccoon dog – an invading species

    DEFF Research Database (Denmark)

    Al-Sabi, Mohammad Nafi Solaiman; Hammer, A. S.; Chriél, Mariann

    2012-01-01

    Invasive species have a marked negative influence on the biodiversity of ecosystems and may contribute to the transmission of diseases. During the 1920s until 1950s, thousands of Raccoon dogs were deliberately introduces to the eastern European countries from the Far East, in order to enrich...... the wild with this new valuable fur animal. The Raccoon dog is considered the most successful invading mammal in Europe, and in the last 20 years, it has invaded the western part of Denmark, namely Jutland. The Danish ministry of Environment reacted to the new threat by deciding to eradicate this species...... species were isolated from both hosts; however, foxes harboured more helminth species per infected animal (average 3,1 helminth species/fox) than raccoon dogs (average 1,7 helminth species/raccoon dog). Prevalences of nematodes (Uncinaria stenocephala, Toxocara canis and Toxascaris leonine) and cestodes...

  17. 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.

  18. 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. ...

  19. 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

    Domestic livestock grazing occurs in virtually all sagebrush habitats and is a prominent disturbance factor. By affecting habitat condition and trend, grazing influences the resources required by, and thus, the distribution and abundance of sagebrush-obligate wildlife species (for example, sage-grouse Centrocercus spp.). Yet, the risks that livestock grazing may pose to these species and their habitats are not always clear. Although livestock grazing intensity and associated habitat condition may be known in many places at the local level, we have not yet been able to answer questions about use, condition, and trend at the landscape scale or at the range-wide scale for wildlife species. A great deal of information about grazing use, management regimes, and ecological condition exists at the local level (for individual livestock management units) under the oversight of organizations such as the Bureau of Land Management (BLM). However, the extent, quality, and types of existing data are unknown, which hinders the compilation, mapping, or analysis of these data. Once compiled, these data may be helpful for drawing conclusions about rangeland status, and we may be able to identify relationships between those data and wildlife habitat at the landscape scale. The overall objective of our study was to perform a range-wide assessment of livestock grazing effects (and the relevant supporting data) in sagebrush ecosystems managed by the BLM. Our assessments and analyses focused primarily on local-level management and data collected at the scale of BLM grazing allotments (that is, individual livestock management units). Specific objectives included the following: 1. Identify and refine existing range-wide datasets to be used for analyses of livestock grazing effects on sagebrush ecosystems. 2. Assess the extent, quality, and types of livestock grazing-related natural resource data collected by BLM range-wide (i.e., across allotments, districts and regions). 3. Compile and

  20. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Common raven occurrence in relation to energy transmission line corridors transiting human-altered sagebrush steppe

    Science.gov (United States)

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

    2014-01-01

    Energy-related infrastructure and other human enterprises within sagebrush steppe of the American West often results in changes that promote common raven (Corvus corax; hereafter, raven) populations. Ravens, a generalist predator capable of behavioral innovation, present a threat to many species of conservation concern. We evaluate the effects of detailed features of an altered landscape on the probability of raven occurrence using extensive raven survey (n= 1045) and mapping data from southern Idaho, USA. We found nonlinear relationships between raven occurrence and distances to transmission lines, roads, and facilities. Most importantly, raven occurrence was greater with presence of transmission lines up to 2.2 km from the corridor.We further explain variation in raven occurrence along anthropogenic features based on the amount of non-native vegetation and cover type edge, such that ravens select fragmented sagebrush stands with patchy, exotic vegetative introgression. Raven occurrence also increased with greater length of edge formed by the contact of big sagebrush (Artemisia tridentate spp.) with non-native vegetation cover types. In consideration of increasing alteration of sagebrush steppe, these findings will be useful for planning energy transmission corridor placement and other management activities where conservation of sagebrush obligate species is a priority.

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

    Science.gov (United States)

    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...

  4. Ecosystem impacts of exotic annual invaders in the genus Bromus

    Science.gov (United States)

    Matthew J. Germino; Jayne Belnap; John M. Stark; Edith B Allen; Benjamin Rau

    2016-01-01

    An understanding of the impacts of exotic plant species on ecosystems is necessary to justify and guide efforts to limit their spread, restore natives, and plan for conservation. Invasive annual grasses such as Bromus tectorum, B. rubens, B. hordeaceus, and B. diandrus (hereafter collectively referred to as Bromus) transform the structure and function of ecosystems...

  5. The effects of insect biological control on a Tamarix invaded ecosystem: ecosystem water and carbon fluxes and plant-level responses

    Science.gov (United States)

    Background / Questions / Methods: Tamarix spp. (saltcedar) has invaded many river systems in the western United States with detrimental impacts to flora and fauna. Traditional methods of invasive plant control have been ineffective or costly. Therefore, insect biological control of Tamarix with Di...

  6. Simulating the Dependence of Sagebrush Steppe Vegetation on Redistributed Snow in a Semi-Arid Watershed.

    Science.gov (United States)

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

    2014-12-01

    In mountainous regions across the western USA, the composition of aspen (Populus tremuloides) and sagebrush steppe plant communities is often closely related to heterogeneous soil moisture subsidies resulting from redistributed snow. With decades of climate and precipitation data across elevational and precipitation gradients, the Reynolds Creek Experimental Watershed (RCEW) and critical zone observatory (CZO) in southwest Idaho provides a unique opportunity to study the relationship between vegetation types and redistributed snow. Within the RCEW, the total amount of precipitation has remained unchanged over the past 50 years, however the percentage of the precipitation falling as snow has declined by approximately 4% per decade at mid-elevation sites. As shifts in precipitation phase continue, future trends in vegetation composition and net primary productivity (NPP) of different plant functional types remains a critical question. We hypothesize that redistribution of snow may supplement drought sensitive species like aspen more so than drought tolerant species like mountain big sagebrush (Artemisia tridentata spp. vaseyana). To assess the importance of snowdrift subsidies on sagebrush steppe vegetation, NPP of aspen, shrub, and grass species was simulated at three sites using the biogeochemical process model BIOME-BGC. Each site is located directly downslope from snowdrifts providing soil moisture inputs to aspen stands and neighboring vegetation. Drifts vary in size with the largest containing up to four times the snow water equivalent (SWE) of a uniform precipitation layer. Precipitation inputs used by BIOME-BGC were modified to represent the redistribution of snow and simulations were run using daily climate data from 1985-2013. Simulated NPP of annual grasses at each site was not responsive to subsidies from drifting snow. However, at the driest site, aspen and shrub annual NPP was increased by as much as 44 and 30%, respectively, with the redistribution of

  7. The Sagebrush Steppe Treatment Evaluation Project (SageSTEP): a test of state-and-transition theory

    Science.gov (United States)

    James D. McIver; Mark Brunson; Steve C. Bunting; Jeanne Chambers; Nora Devoe; Paul Doescher; James Grace; Dale Johnson; Steve Knick; Richard Miller; Mike Pellant; Fred Pierson; David Pyke; Kim Rollins; Bruce Roundy; Eugene Schupp; Robin Tausch; David Turner

    2010-01-01

    The Sagebrush Steppe Treatment Evaluation Project (SageSTEP) is a comprehensive, integrated, long-term study that evaluates the ecological effects of fire and fire surrogate treatments designed to reduce fuel and to restore sagebrush (Artemisia spp.) communities of the Great Basin and surrounding areas. SageSTEP has several features that make it ideal for testing...

  8. Alien plant invasions--incorporating emerging invaders in regional prioritization: a pragmatic approach for Southern Africa.

    Science.gov (United States)

    Mgidi, Theresa N; Le Maitre, David C; Schonegevel, Lucille; Nel, Jeanne L; Rouget, Mathieu; Richardson, David M

    2007-07-01

    Plant invasions are a serious threat to natural and semi-natural ecosystems worldwide. Most management-orientated research on invasions focuses on invaders that are already widespread and often have major impacts. This paper deals with "emerging" invaders-those alien species with the potential to become important problems without timely intervention. A climate matching procedure was developed to define areas of South Africa, Lesotho and Swaziland that could be invaded by 28 plant species that had previously been classified as emerging invaders. Information on the location of populations of these species in the study area was combined with information on their distributions (as native or alien) in parts of Australia and the United States of America. These two countries had the best available distribution data for this study. They also share many invasive alien plant species with South Africa. Climatic data obtained for weather stations near points of known occurrence in these countries were used to define the climatically suitable areas for each species in the study area. Almost 80% of the remaining natural environment in southern Africa was found to be vulnerable to invasion by at least one of these species, 50% by six or more and 24% by 16 or more species. The most vulnerable areas are the highveld grasslands and the eastern escarpment. The emerging invaders with the greatest potential range included Acacia podalyriifolia and Cortaderia selloana. The globally important invaders Ulex europaeus and Lythrum salicaria had a more limited invasion potential but could still become major invaders. There was no relationship between the extent of the climatically suitable areas for the different species and an expert ranking of their invasion potential, emphasising the uncertainties inherent in making expert assessments based on very little information. The methods used in this analysis establish a protocol for future modelling exercises to assess the invasion potential of

  9. Effects of a Major Tree Invader on Urban Woodland Arthropods

    Science.gov (United States)

    2015-01-01

    Biological invasions are a major threat to biodiversity; however, the degree of impact can vary depending on the ecosystem and taxa. Here, we test whether a top invader at a global scale, the tree Robinia pseudoacacia (black locust or false acacia), which is known to profoundly change site conditions, significantly affects urban animal diversity. As a first multi-taxon study of this kind, we analyzed the effects of Robinia dominance on 18 arthropod taxa by pairwise comparisons of woodlands in Berlin, Germany, that were dominated by R. pseudoacacia or the native pioneer tree Betula pendula. As a negative effect, abundances of five arthropod taxa decreased (Chilopoda, Formicidae, Diptera, Heteroptera, Hymenoptera); 13 others were not affected. Woodland type affected species composition of carabids and functional groups in spiders, but surprisingly did not decrease alpha and beta diversity of carabid and spider assemblages or the number of endangered species. Tree invasion thus did not induce biotic homogenization at the habitat scale. We detected no positive effects of alien dominance. Our results illustrate that invasions by a major tree invader can induce species turnover in ground-dwelling arthropods, but do not necessarily reduce arthropod species abundances or diversity and might thus contribute to the conservation of epigeal invertebrates in urban settings. Considering the context of invasion impacts thus helps to set priorities in managing biological invasions and can illustrate the potential of novel ecosystems to maintain urban biodiversity. PMID:26359665

  10. Effects of a Major Tree Invader on Urban Woodland Arthropods.

    Directory of Open Access Journals (Sweden)

    Sascha Buchholz

    Full Text Available Biological invasions are a major threat to biodiversity; however, the degree of impact can vary depending on the ecosystem and taxa. Here, we test whether a top invader at a global scale, the tree Robinia pseudoacacia (black locust or false acacia, which is known to profoundly change site conditions, significantly affects urban animal diversity. As a first multi-taxon study of this kind, we analyzed the effects of Robinia dominance on 18 arthropod taxa by pairwise comparisons of woodlands in Berlin, Germany, that were dominated by R. pseudoacacia or the native pioneer tree Betula pendula. As a negative effect, abundances of five arthropod taxa decreased (Chilopoda, Formicidae, Diptera, Heteroptera, Hymenoptera; 13 others were not affected. Woodland type affected species composition of carabids and functional groups in spiders, but surprisingly did not decrease alpha and beta diversity of carabid and spider assemblages or the number of endangered species. Tree invasion thus did not induce biotic homogenization at the habitat scale. We detected no positive effects of alien dominance. Our results illustrate that invasions by a major tree invader can induce species turnover in ground-dwelling arthropods, but do not necessarily reduce arthropod species abundances or diversity and might thus contribute to the conservation of epigeal invertebrates in urban settings. Considering the context of invasion impacts thus helps to set priorities in managing biological invasions and can illustrate the potential of novel ecosystems to maintain urban biodiversity.

  11. Effects of a Major Tree Invader on Urban Woodland Arthropods.

    Science.gov (United States)

    Buchholz, Sascha; Tietze, Hedwig; Kowarik, Ingo; Schirmel, Jens

    2015-01-01

    Biological invasions are a major threat to biodiversity; however, the degree of impact can vary depending on the ecosystem and taxa. Here, we test whether a top invader at a global scale, the tree Robinia pseudoacacia (black locust or false acacia), which is known to profoundly change site conditions, significantly affects urban animal diversity. As a first multi-taxon study of this kind, we analyzed the effects of Robinia dominance on 18 arthropod taxa by pairwise comparisons of woodlands in Berlin, Germany, that were dominated by R. pseudoacacia or the native pioneer tree Betula pendula. As a negative effect, abundances of five arthropod taxa decreased (Chilopoda, Formicidae, Diptera, Heteroptera, Hymenoptera); 13 others were not affected. Woodland type affected species composition of carabids and functional groups in spiders, but surprisingly did not decrease alpha and beta diversity of carabid and spider assemblages or the number of endangered species. Tree invasion thus did not induce biotic homogenization at the habitat scale. We detected no positive effects of alien dominance. Our results illustrate that invasions by a major tree invader can induce species turnover in ground-dwelling arthropods, but do not necessarily reduce arthropod species abundances or diversity and might thus contribute to the conservation of epigeal invertebrates in urban settings. Considering the context of invasion impacts thus helps to set priorities in managing biological invasions and can illustrate the potential of novel ecosystems to maintain urban biodiversity.

  12. Invasive aquarium fish transform ecosystem nutrient dynamics

    Science.gov (United States)

    Capps, Krista A.; Flecker, Alexander S.

    2013-01-01

    Trade of ornamental aquatic species is a multi-billion dollar industry responsible for the introduction of myriad fishes into novel ecosystems. Although aquarium invaders have the potential to alter ecosystem function, regulation of the trade is minimal and little is known about the ecosystem-level consequences of invasion for all but a small number of aquarium species. Here, we demonstrate how ecological stoichiometry can be used as a framework to identify aquarium invaders with the potential to modify ecosystem processes. We show that explosive growth of an introduced population of stoichiometrically unique, phosphorus (P)-rich catfish in a river in southern Mexico significantly transformed stream nutrient dynamics by altering nutrient storage and remineralization rates. Notably, changes varied between elements; the P-rich fish acted as net sinks of P and net remineralizers of nitrogen. Results from this study suggest species-specific stoichiometry may be insightful for understanding how invasive species modify nutrient dynamics when their population densities and elemental composition differ substantially from native organisms. Risk analysis for potential aquarium imports should consider species traits such as body stoichiometry, which may increase the likelihood that an invasion will alter the structure and function of ecosystems. PMID:23966642

  13. Litter drives ecosystem and plant community changes in cattail invasion.

    Science.gov (United States)

    Farrer, Emily C; Goldberg, Deborah E

    2009-03-01

    Invaded systems are commonly associated with a change in ecosystem processes and a decline in native species diversity; however, many different causal pathways linking invasion, ecosystem change, and native species decline could produce this pattern. The initial driver of environmental change may be anthropogenic, or it may be the invader itself; and the mechanism behind native species decline may be the human-induced environmental change, competition from the invader, or invader-induced environmental change (non-trophic effects). We examined applicability of each of these alternate pathways in Great Lakes coastal marshes invaded by hybrid cattail (Typha x glauca). In a survey including transects in three marshes, we found that T. x glauca was associated with locally high soil nutrients, low light, and large amounts of litter, and that native diversity was highest in areas of shallow litter depth. We tested whether live T. x glauca plants or their litter induced changes in the environment and in diversity with a live plant and litter transplant experiment. After one year, Typha litter increased soil NH4+ and N mineralization twofold, lowered light levels, and decreased the abundance and diversity of native plants, while live Typha plants had no effect on the environment or on native plants. This suggests that T. x glauca, through its litter production, can cause the changes in ecosystem processes that we commonly attribute to anthropogenic nutrient loading and that T. x glauca does not displace native species through competition for resources, but rather affects them non-trophically through its litter. Moreover, because T. x glauca plants were taller when grown with their own litter, we suggest that this invader may produce positive feedbacks and change the environment in ways that benefit itself and may promote its own invasion.

  14. 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...

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Relative roles of climatic suitability and anthropogenic influence in determining the pattern of spread in a global invader

    DEFF Research Database (Denmark)

    Roura-Pascual, Núria; Hui, Cang; Ikeda, Takayoshi

    2011-01-01

    Because invasive species threaten the integrity of natural ecosystems, a major goal in ecology is to develop predictive models to determine which species may become widespread and where they may invade. Indeed, considerable progress has been made in understanding the factors that influence the lo...

  17. Stoichiometric Constraints Do Not Limit Successful Invaders: Zebra Mussels in Swedish Lakes

    OpenAIRE

    Naddafi, Rahmat; Ekl?v, Peter; Pettersson, Kurt

    2009-01-01

    Background Elemental imbalances of carbon (C): nitrogen (N): phosphorus (P) ratios in food resources can constrain the growth of grazers owning to tight coupling between growth rate, RNA allocation and biomass P content in animals. Testing for stoichiometric constraints among invasive species is a novel challenge in invasion ecology to unravel how a successful invader tackles ecological barriers in novel ecosystems. Methodology/Principal Findings We examined the C?P and N?P ratios and the con...

  18. Enhanced precipitation promotes decomposition and soil C stabilization in semiarid ecosystems, but seasonal timing of wetting matters

    Science.gov (United States)

    Campos, Xochi; Germino, Matthew; de Graaff, Marie-Anne

    2017-01-01

    AimsChanging precipitation regimes in semiarid ecosystems will affect the balance of soil carbon (C) input and release, but the net effect on soil C storage is unclear. We asked how changes in the amount and timing of precipitation affect litter decomposition, and soil C stabilization in semiarid ecosystems.MethodsThe study took place at a long-term (18 years) ecohydrology experiment located in Idaho. Precipitation treatments consisted of a doubling of annual precipitation (+200 mm) added either in the cold-dormant season or in the growing season. Experimental plots were planted with big sagebrush (Artemisia tridentata), or with crested wheatgrass (Agropyron cristatum). We quantified decomposition of sagebrush leaf litter, and we assessed organic soil C (SOC) in aggregates, and silt and clay fractions.ResultsWe found that: (1) increased precipitation applied in the growing season consistently enhanced decomposition rates relative to the ambient treatment, and (2) precipitation applied in the dormant season enhanced soil C stabilization.ConclusionsThese data indicate that prolonged increases in precipitation can promote soil C storage in semiarid ecosystems, but only if these increases happen at times of the year when conditions allow for precipitation to promote plant C inputs rates to soil.

  19. Invasion Age and Invader Removal Alter Species Cover and Composition at the Suisun Tidal Marsh, California, USA

    Directory of Open Access Journals (Sweden)

    Sarah Estrella

    2011-05-01

    Full Text Available Wetland ecosystems are vulnerable to plant species invasions, which can greatly alter species composition and ecosystem functioning. The response of these communities to restoration can vary following invader removal, but few studies have evaluated how recent and long-term invasions can affect the plant community’s restoration potential. Perennial pepperweed (Lepidium latifolium has invaded thousands of hectares of marshland in the San Francisco Estuary, California, United States of America, while the effects of invasion and removal of this weed remain poorly studied. In this study, perennial pepperweed was removed along a gradient of invasion age in brackish tidal marshes of Suisun Marsh, within the Estuary. In removal plots, resident plant cover significantly increased during the 2-year study period, particularly in the densest and oldest parts of the perennial pepperweed colonies, while species richness did not change significantly. In bare areas created by removal of perennial pepperweed, recolonization was dominated by three-square bulrush (Schoenoplectus americanus. Ultimately, removal of invasive perennial pepperweed led to reinvasion of the resident plant community within two years. This study illustrates that it is important to consider invasion age, along with exotic species removal, when developing a restoration strategy in wetland ecosystems.

  20. Synergy of extreme drought and shrub invasion reduce ecosystem functioning and resilience in water-limited climates

    Science.gov (United States)

    Caldeira, Maria C.; Lecomte, Xavier; David, Teresa S.; Pinto, Joaquim G.; Bugalho, Miguel N.; Werner, Christiane

    2015-10-01

    Extreme drought events and plant invasions are major drivers of global change that can critically affect ecosystem functioning and alter ecosystem-atmosphere exchange. Invaders are expanding worldwide and extreme drought events are projected to increase in frequency and intensity. However, very little is known on how these drivers may interact to affect the functioning and resilience of ecosystems to extreme events. Using a manipulative shrub removal experiment and the co-occurrence of an extreme drought event (2011/2012) in a Mediterranean woodland, we show that native shrub invasion and extreme drought synergistically reduced ecosystem transpiration and the resilience of key-stone oak tree species. Ecosystem transpiration was dominated by the water use of the invasive shrub Cistus ladanifer, which further increased after the extreme drought event. Meanwhile, the transpiration of key-stone tree species decreased, indicating a competitive advantage in favour of the invader. Our results suggest that in Mediterranean-type climates the invasion of water spending species and projected recurrent extreme drought events may synergistically cause critical drought tolerance thresholds of key-stone tree species to be surpassed, corroborating observed higher tree mortality in the invaded ecosystems. Ultimately, this may shift seasonally water limited ecosystems into less desirable alternative states dominated by water spending invasive shrubs.

  1. 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

  2. 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

  3. 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

  4. 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

  5. Using life strategies to explore the vulnerability of ecosystem services to invasion by alien plants

    NARCIS (Netherlands)

    Vicente, J.; Pinro, A.; Araujo, M.; Lomba, A.; Randin, C.; Guisan, A.; Honrado, J.; Verburg, P.H.

    2013-01-01

    Invasive plants can have different effects on ecosystem functioning and on the provision of ecosystem services, with the direction and magnitude of such effects depending on the service and ecosystem being considered, but also on the life strategies of the invaders. Strategies can influence

  6. Biological invasions in forest ecosystems

    Science.gov (United States)

    Andrew M. Liebhold; Eckehard G. Brockerhoff; Susan Kalisz; Martin A. Nuñez; David A. Wardle; Michael J. Wingfield

    2017-01-01

    Forests play critical roles in global ecosystem processes and provide numerous services to society. But forests are increasingly affected by a variety of human influences, especially those resulting from biological invasions. Species invading forests include woody and herbaceous plants, many animal species including mammals and invertebrates, as well as a variety of...

  7. An invasive foundation species enhances multifunctionality in a coastal ecosystem.

    Science.gov (United States)

    Ramus, Aaron P; Silliman, Brian R; Thomsen, Mads S; Long, Zachary T

    2017-08-08

    While invasive species often threaten biodiversity and human well-being, their potential to enhance functioning by offsetting the loss of native habitat has rarely been considered. We manipulated the abundance of the nonnative, habitat-forming seaweed Gracilaria vermiculophylla in large plots (25 m 2 ) on southeastern US intertidal landscapes to assess impacts on multiple ecosystem functions underlying coastal ecosystem services. We document that in the absence of native habitat formers, this invasion has an overall positive, density-dependent impact across a diverse set of ecosystem processes (e.g., abundance and richness of nursery taxa, flow attenuation). Manipulation of invader abundance revealed both thresholds and saturations in the provisioning of ecosystem functions. Taken together, these findings call into question the focus of traditional invasion research and management that assumes negative effects of nonnatives, and emphasize the need to consider context-dependence and integrative measurements when assessing the impact of an invader, including density dependence, multifunctionality, and the status of native habitat formers. This work supports discussion of the idea that where native foundation species have been lost, invasive habitat formers may be considered as sources of valuable ecosystem functions.

  8. 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...

  9. 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...

  10. Comparison of ground beetle (Coleoptera: Carabidae) assemblages in Rocky Mountain savannas invaded and un-invaded by an exotic forb, spotted knapweed

    Science.gov (United States)

    Allison K. Hansen; Yvette K. Ortega; Diana L. Six

    2009-01-01

    We compared ground beetle (Carabidae) assemblages between spotted knapweed (Centaurea maculosa Lam.) -invaded (invaded) and un-invaded (native) habitats in Rocky Mountain savannas. Carabids play important roles in biotic communities and are known as a good indictor group of environmental change. Carabid species activity-abundance and diversity were estimated, and...

  11. Mechanical mastication of Utah juniper encroaching sagebrush steppe increases inorganic soil N

    Science.gov (United States)

    Juniper (Juniperus spp.) has encroached millions of hectares of sagebrush (Artemisia spp.) steppe. Juniper mechanical mastication increases cover of understory species, but could increase resource availability and subsequently invasive plant species. We quantified the effects of juniper mastication ...

  12. 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

  13. Long-term effects of wildfire on greater sage-grouse - integrating population and ecosystem concepts for management in the Great Basin

    Science.gov (United States)

    Coates, Peter S.; Ricca, Mark A.; Prochazka, Brian G.; Doherty, Kevin E.; Brooks, Matthew L.; Casazza, Michael L.

    2015-09-10

    Greater sage-grouse (Centrocercus urophasianus; hereinafter, sage-grouse) are a sagebrush obligate species that has declined concomitantly with the loss and fragmentation of sagebrush ecosystems across most of its geographical range. The species currently is listed as a candidate for federal protection under the Endangered Species Act (ESA). Increasing wildfire frequency and changing climate frequently are identified as two environmental drivers that contribute to the decline of sage-grouse populations, yet few studies have rigorously quantified their effects on sage-grouse populations across broad spatial scales and long time periods. To help inform a threat assessment within the Great Basin for listing sage-grouse in 2015 under the ESA, we conducted an extensive analysis of wildfire and climatic effects on sage-grouse population growth derived from 30 years of lek-count data collected across the hydrographic Great Basin of Western North America. Annual (1984–2013) patterns of wildfire were derived from an extensive dataset of remotely sensed 30-meter imagery and precipitation derived from locally downscaled spatially explicit data. In the sagebrush ecosystem, underlying soil conditions also contribute strongly to variation in resilience to disturbance and resistance to plant community changes (R&R). Thus, we developed predictions from models of post-wildfire recovery and chronic effects of wildfire based on three spatially explicit R&R classes derived from soil moisture and temperature regimes. We found evidence of an interaction between the effects of wildfire (chronically affected burned area within 5 kilometers of a lek) and climatic conditions (spring through fall precipitation) after accounting for a consistent density-dependent effect. Specifically, burned areas near leks nullifies population growth that normally follows years with relatively high precipitation. In models, this effect results in long-term population declines for sage-grouse despite cyclic

  14. 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).

  15. Short- and longterm impacts of Acacia longifolia invasion on belowground processes of a Mediterranean coastal dune ecosystem

    DEFF Research Database (Denmark)

    Marchante, Elizabete; Kjøller, Annelise; Struwe, Sten

    2008-01-01

    to new areas, displacing the native vegetation. These invaded ecosystems contrast with the native dune ecosystems that are typically dominated by herb and shrub communities. This study characterizes belowground changes to the native environment as a result of recent (20 y...

  16. Lake Michigan offshore ecosystem structure and food web changes from 1987 to 2008

    Science.gov (United States)

    Rogers, Mark W.; Bunnell, David B.; Madenjian, Charles P.; Warner, David M.

    2014-01-01

    Ecosystems undergo dynamic changes owing to species invasions, fisheries management decisions, landscape modifications, and nutrient inputs. At Lake Michigan, new invaders (e.g., dreissenid mussels (Dreissena spp.), spiny water flea (Bythotrephes longimanus), round goby (Neogobius melanostomus)) have proliferated and altered energy transfer pathways, while nutrient concentrations and stocking rates to support fisheries have changed. We developed an ecosystem model to describe food web structure in 1987 and ran simulations through 2008 to evaluate changes in biomass of functional groups, predator consumption, and effects of recently invading species. Keystone functional groups from 1987 were identified as Mysis, burbot (Lota lota), phytoplankton, alewife (Alosa pseudoharengus), nonpredatory cladocerans, and Chinook salmon (Oncorhynchus tshawytscha). Simulations predicted biomass reductions across all trophic levels and predicted biomasses fit observed trends for most functional groups. The effects of invasive species (e.g., dreissenid grazing) increased across simulation years, but were difficult to disentangle from other changes (e.g., declining offshore nutrient concentrations). In total, our model effectively represented recent changes to the Lake Michigan ecosystem and provides an ecosystem-based tool for exploring future resource management scenarios.

  17. 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 (

  18. Management considerations

    Science.gov (United States)

    Steven T. Knick; Steven E. Hanser; Matthias Leu; Cameron L. Aldridge; Scott E. Neilsen; Mary M. Rowland; Sean P. Finn; Michael J. Wisdom

    2011-01-01

    We conducted an ecoregional assessment of sagebrush (Artemisia spp.) ecosystems in the Wyoming Basins and surrounding regions (WBEA) to determine broad-scale species-environmental relationships. Our goal was to assess the potential influence from threats to the sagebrush ecosystem on associated wildlife through the use of spatially explicit...

  19. Ecosystem transformations of the Laurentian Great Lake Michigan by nonindigenous biological invaders.

    Science.gov (United States)

    Cuhel, Russell L; Aguilar, Carmen

    2013-01-01

    Lake Michigan, a 58,000-km(2) freshwater inland sea, is large enough to have persistent basin-scale circulation yet small enough to enable development of approximately balanced budgets for water, energy, and elements including carbon and silicon. Introduction of nonindigenous species-whether through invasion, intentional stocking, or accidental transplantation-has transformed the lake's ecosystem function and habitat structure. Of the 79 nonindigenous species known to have established reproductive populations in the lake, only a few have brought considerable ecological pressure to bear. Four of these were chosen for this review to exemplify top-down (sea lamprey, Petromyzon marinus), middle-out (alewife, Alosa pseudoharengus), and bottom-up (the dreissenid zebra and quagga mussels, Dreissena polymorpha and Dreissena rostriformis bugensis, respectively) transformations of Lake Michigan ecology, habitability, and ultimately physical environment. Lampreys attacked and extirpated indigenous lake trout, the top predator. Alewives outcompeted native planktivorous fish and curtailed invertebrate populations. Dreissenid mussels-especially quagga mussels, which have had a much greater impact than the preceding zebra mussels-moved ecosystem metabolism basin-wide from water column to bottom dominance and engineered structures throughout the lake. Each of these non indigenous species exerted devastating effects on commercial and sport fisheries through ecosystem structure modification.

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

    Science.gov (United States)

    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,...

  1. 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.

  2. Prescribed fire, soil, and plants: burn effects and interactions in the central Great Basin

    Science.gov (United States)

    Benjamin M. Rau; Jeanne C. Chambers; Robert R. Blank; Dale W. Johnson

    2008-01-01

    Pinyon and juniper expansion into sagebrush ecosystems results in decreased cover and biomass of perennial grasses and forbs. We examine the effectiveness of spring prescribed fire on restoration of sagebrush ecosystems by documenting burn effects on soil nutrients, herbaceous aboveground biomass, and tissue nutrient concentrations. This study was conducted in a...

  3. 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....

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Powerful qPCR assays for the early detection of latent invaders: interdisciplinary approaches in clinical cancer research and plant pathology.

    Science.gov (United States)

    Luchi, Nicola; Capretti, Paolo; Pazzagli, Mario; Pinzani, Pamela

    2016-06-01

    Latent invaders represent the first step of disease before symptoms occur in the host. Based on recent findings, tumors are considered to be ecosystems in which cancer cells act as invasive species that interact with the native host cell species. Analogously, in plants latent fungal pathogens coevolve within symptomless host tissues. For these reasons, similar detection approaches can be used for an early diagnosis of the invasion process in both plants and humans to prevent or reduce the spread of the disease. Molecular tools based on the evaluation of nucleic acids have been developed for the specific, rapid, and early detection of human diseases. During the last decades, these techniques to assess and quantify the proliferation of latent invaders in host cells have been transferred from the medical field to different areas of scientific research, such as plant pathology. An improvement in molecular biology protocols (especially referring to qPCR assays) specifically designed and optimized for detection in host plants is therefore advisable. This work is a cross-disciplinary review discussing the use of a methodological approach that is employed within both medical and plant sciences. It provides an overview of the principal qPCR tools for the detection of latent invaders, focusing on comparisons between clinical cancer research and plant pathology, and recent advances in the early detection of latent invaders to improve prevention and control strategies.

  6. 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...

  7. 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...

  8. 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

  9. 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.

  10. Understory cover responses to pinon-juniper treatments across tree dominance gradients in the Great Basin

    Science.gov (United States)

    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...

  11. Stoichiometric constraints do not limit successful invaders: zebra mussels in Swedish lakes.

    Science.gov (United States)

    Naddafi, Rahmat; Eklöv, Peter; Pettersson, Kurt

    2009-01-01

    Elemental imbalances of carbon (C): nitrogen (N): phosphorus (P) ratios in food resources can constrain the growth of grazers owning to tight coupling between growth rate, RNA allocation and biomass P content in animals. Testing for stoichiometric constraints among invasive species is a novel challenge in invasion ecology to unravel how a successful invader tackles ecological barriers in novel ecosystems. We examined the C:P and N:P ratios and the condition factor of a successful invader in lakes, the zebra mussel (Dreissena polymorpha), collected from two Swedish lakes. Concurrently, we analyzed the elemental composition of the food (seston) and tissue of the mussels in which nutrient composition of food and mussels varied over time. Zebra mussel condition factor was weakly related to the their own tissue N:P and C:P ratios, although the relation with the later ratio was not significant. Smaller mussels had relatively lower tissue N:P ratio and higher condition factor. There was no difference in C:P and N:P ratios between seston and mussels' tissues. Our results indicated that the variation in nutrient stoichiometry of zebra mussels can be explained by food quality and quantity. Our study suggests that fitness of invasive zebra mussels is not constrained by nutrient stoichiometry which is likely to be important for their proliferation in novel ecosystems. The lack of imbalance in C:P and N:P ratios between seston and mussels along with high tissue C:P ratio of the mussel allow them to tolerate potential P limitation and maintain high growth rate. Moreover, zebra mussels are able to change their tissue C:P and N:P ratios in response to the variation in elemental composition of their food. This can also help them to bypass potential nutrient stoichiometric constraints. Our finding is an important step towards understanding the mechanisms contributing to the success of exotic species from stoichiometric principles.

  12. Stoichiometric constraints do not limit successful invaders: zebra mussels in Swedish lakes.

    Directory of Open Access Journals (Sweden)

    Rahmat Naddafi

    Full Text Available Elemental imbalances of carbon (C: nitrogen (N: phosphorus (P ratios in food resources can constrain the growth of grazers owning to tight coupling between growth rate, RNA allocation and biomass P content in animals. Testing for stoichiometric constraints among invasive species is a novel challenge in invasion ecology to unravel how a successful invader tackles ecological barriers in novel ecosystems.We examined the C:P and N:P ratios and the condition factor of a successful invader in lakes, the zebra mussel (Dreissena polymorpha, collected from two Swedish lakes. Concurrently, we analyzed the elemental composition of the food (seston and tissue of the mussels in which nutrient composition of food and mussels varied over time. Zebra mussel condition factor was weakly related to the their own tissue N:P and C:P ratios, although the relation with the later ratio was not significant. Smaller mussels had relatively lower tissue N:P ratio and higher condition factor. There was no difference in C:P and N:P ratios between seston and mussels' tissues. Our results indicated that the variation in nutrient stoichiometry of zebra mussels can be explained by food quality and quantity.Our study suggests that fitness of invasive zebra mussels is not constrained by nutrient stoichiometry which is likely to be important for their proliferation in novel ecosystems. The lack of imbalance in C:P and N:P ratios between seston and mussels along with high tissue C:P ratio of the mussel allow them to tolerate potential P limitation and maintain high growth rate. Moreover, zebra mussels are able to change their tissue C:P and N:P ratios in response to the variation in elemental composition of their food. This can also help them to bypass potential nutrient stoichiometric constraints. Our finding is an important step towards understanding the mechanisms contributing to the success of exotic species from stoichiometric principles.

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

    Science.gov (United States)

    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.

  14. Grassland invader responses to realistic changes in native species richness.

    Science.gov (United States)

    Rinella, Matthew J; Pokorny, Monica L; Rekaya, Romdhane

    2007-09-01

    The importance of species richness for repelling exotic plant invasions varies from ecosystem to ecosystem. Thus, in order to prioritize conservation objectives, it is critical to identify those ecosystems where decreasing richness will most greatly magnify invasion risks. Our goal was to determine if invasion risks greatly increase in response to common reductions in grassland species richness. We imposed treatments that mimic management-induced reductions in grassland species richness (i.e., removal of shallow- and/or deep-rooted forbs and/or grasses and/or cryptogam layers). Then we introduced and monitored the performance of a notorious invasive species (i.e., Centaurea maculosa). We found that, on a per-gram-of-biomass basis, each resident plant group similarly suppressed invader growth. Hence, with respect to preventing C. maculosa invasions, maintaining overall productivity is probably more important than maintaining the productivity of particular plant groups or species. But at the sites we studied, all plant groups may be needed to maintain overall productivity because removing forbs decreased overall productivity in two of three years. Alternatively, removing forbs increased productivity in another year, and this led us to posit that removing forbs may inflate the temporal productivity variance as opposed to greatly affecting time-averaged productivity. In either case, overall productivity responses to single plant group removals were inconsistent and fairly modest, and only when all plant groups were removed did C. maculosa growth increase substantially over a no-removal treatment. As such, it seems that intense disturbances (e.g., prolonged drought, overgrazing) that deplete multiple plant groups may often be a prerequisite for C. maculosa invasion.

  15. Biological invasions on oceanic islands: Implications for island ecosystems and avifauna

    Science.gov (United States)

    Dean E. Pearson

    2009-01-01

    Biological invasions present a global threat to biodiversity, but oceanic islands are the systems hardest hit by invasions. Islands are generally depauperate in species richness, trophic complexity, and functional diversity relative to comparable mainland ecosystems. This situation results in low biotic resistance to invasion and many empty niches for invaders to...

  16. Invaders interfere with native parasite-host interactions

    DEFF Research Database (Denmark)

    Thieltges, David W.; Reise, Karsten; Prinz, Katrin

    2009-01-01

    The introduction of species is of increasing concern as invaders often reduce the abundance of native species due to a variety of interactions like habitat engineering, predation and competition. A more subtle and not recognized effect of invaders on their recipient biota is their potential...... interference with native parasite-host interactions. Here, we experimentally demonstrate that two invasive molluscan filter-feeders of European coastal waters interfere with the transmission of free-living infective trematode larval stages and hereby mitigate the parasite burden of native mussels (Mytilus...

  17. Metabolic characterization of invaded cells of the pancreatic cancer cell line, PANC-1.

    Science.gov (United States)

    Fujita, Mayumi; Imadome, Kaori; Imai, Takashi

    2017-05-01

    We previously reported that about 0.4% of cells in the cultured human pancreatic cancer cell line, PANC-1, can invade matrigel during the transwell invasion assay, suggesting that these invaded PANC-1 cells may have specific characteristics to keep their invasive potential. To identify the metabolic characterization specific in the invaded PANC-1 cells, metabolome analysis of the invaded PANC-1 compared with the whole cultured PANC-1 was performed using CE-TOFMS, and concentrations of 110 metabolites were measured. In contrast to the whole cultured cells, the invaded PANC-1 was characterized as a population with reduced levels of amino acids and TCA cycle intermediates, and decreased and increased intermediates in glycolysis and nucleic acid metabolism. In particular, the ratio of both adenosine and guanosine energy charge was reduced in the invaded cells, revealing that the consumption of ATP and GTP was high in the invaded cells, and thus suggesting that ATP- or GTP-generating pathways are stimulated. In addition, the GSH/GSSG ratio was low in the invaded cells, but these cells had a higher surviving fraction after exposure to hydrogen peroxide. Thus, the invaded cells were the population resistant to oxidative stress. Furthermore, reduction in intracellular GSH content inhibited PANC-1 invasiveness, indicated that GSH has an important role in PANC-1 invasiveness. Overall, we propose the invaded cells have several unique metabolic profiles. © 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  18. Review of ecosystem level impacts of emerald ash borer on black ash wetlands: What does the future hold?

    Science.gov (United States)

    Randall K. Kolka; Anthony W. D' Amato; Joseph W. Wagenbrenner; Robert A. Slesak; Thomas G. Pypker; Melissa B. Youngquist; Alexis R. Grinde; Brian J. Palik

    2018-01-01

    The emerald ash borer (EAB) is rapidly spreading throughout eastern North America and devastating ecosystems where ash is a component tree. This rapid and sustained loss of ash trees has already resulted in ecological impacts on both terrestrial and aquatic ecosystems and is projected to be even more severe as EAB invades black ash-dominated wetlands of the western...

  19. Exotic woody plant invaders of the Transvaal

    Directory of Open Access Journals (Sweden)

    L. Henderson

    1984-12-01

    Full Text Available The frequency and abundance o ;f exotic, woody plant invaders were recorded in 60% of the quarter degree squares in the study area. Sixty-one invaders were encountered o f which the most important and aggressive were Acacia dealbaia, Populus spp.,  Melia azedarach, Opuntia ficus-indica, Salix babylonica and  Acacia mearnsii. Invasion patterns are discussed and an attempt is made to correlate distribution with environmental factors. Attention is drawn to the areas of greatest invasion and the areas that are liable to show the greatest expansion in the future.

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

    Science.gov (United States)

    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

  1. Evolution of competitive ability within Lonicera japonica's invaded range

    Science.gov (United States)

    Gregory A. Evans; Francis F. Kilkenny; Laura F. Galloway

    2013-01-01

    Factors influencing invasive taxa may change during the course of an invasion. For example, intraspecific competition is predicted to be more important in areas with older stands of dense monospecific invaders than at the margins of an invaded range. We evaluated evolution in response to predicted changes in competition by comparing the intraspecific competitive...

  2. 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...

  3. Mapping cryptic invaders and invisability of tropical forest ecosystems: Chromolaena odorata in Nepal

    NARCIS (Netherlands)

    Joshi, C.

    2006-01-01

    For centuries, people continuously increased the rate of biological invasions and there is no sign of slowing down. From the depth of the Ocean to the crest of Himalayas, they are occupying pristine and semi-natural ecosystems at an alarming rate, threatening human, animal, plant as well as

  4. Insect community responses to climate and weather across elevation gradients in the Sagebrush Steppe, eastern Oregon

    Science.gov (United States)

    Pilliod, David S.; Rohde, Ashley T.

    2016-11-17

    insect communities respond positively and negatively to weather and local vegetation more than to long-term climate. Given increasing variability in weather and high probability of extreme weather events, insect communities in sagebrush steppe also may experience considerable fluctuations in composition and abundance, as well as phenology. These findings have implications for many ecosystem services, including pollination, decomposition, and food resources for predatory birds and other vertebrates.

  5. Variations of selected soil properties in the grass fields invaded and uninvaded by invasive goldenrod (Solidago canadensis L.

    Directory of Open Access Journals (Sweden)

    Baranová Beáta

    2017-06-01

    Full Text Available Although the invasion of exotic plants has been recognised as the serious cause of the biodiversity loss and natural habitats degradation and threat to the ecosystems functions, just the little attention has been paid to the potential impacts of the goldenrod invasion on the soil properties. Equally, currently obtained results are contrary and ambiguous. We tested whether the grass fields invaded and uninvaded by Canadian goldenrod (Solidago canadensis L. differ in pH, soil moisture, organic carbon (Cox, humus and P, K and Mg contents and related the variations to the chosen environmental variables. We did not find significant distinctions of the studied types of habitats in the selected physico-chemical soil properties as well as the relation between the goldenrod invasion and the changes in soil properties. Nevertheless, whereas the soil reaction, soil moisture and Mg content were higher in the invaded soils, the Cox, humus and P and K contents were higher in the uninvaded ones. Doubtless, further attention need to be paid to this problem.

  6. Nitrogen and Carbon Cycling in a Grassland Community Ecosystem as Affected by Elevated Atmospheric CO2

    Directory of Open Access Journals (Sweden)

    H. A. Torbert

    2012-01-01

    Full Text Available Increasing global atmospheric carbon dioxide (CO2 concentration has led to concerns regarding its potential effects on terrestrial ecosystems and the long-term storage of carbon (C and nitrogen (N in soil. This study examined responses to elevated CO2 in a grass ecosystem invaded with a leguminous shrub Acacia farnesiana (L. Willd (Huisache. Seedlings of Acacia along with grass species were grown for 13 months at CO2 concentrations of 385 (ambient, 690, and 980 μmol mol−1. Elevated CO2 increased both C and N inputs from plant growth which would result in higher soil C from litter fall, root turnover, and excretions. Results from the incubation indicated an initial (20 days decrease in N mineralization which resulted in no change in C mineralization. However, after 40 and 60 days, an increase in both C and N mineralization was observed. These increases would indicate that increases in soil C storage may not occur in grass ecosystems that are invaded with Acacia over the long term.

  7. 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...

  8. 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...

  9. A conservation planning tool for Greater Sage-grouse using indices of species distribution, resilience, and resistance.

    Science.gov (United States)

    Ricca, Mark A; Coates, Peter S; Gustafson, K Benjamin; Brussee, Brianne E; Chambers, Jeanne C; Espinosa, Shawn P; Gardner, Scott C; Lisius, Sherri; Ziegler, Pilar; Delehanty, David J; Casazza, Michael L

    2018-06-01

    Managers require quantitative yet tractable tools that identify areas for restoration yielding effective benefits for targeted wildlife species and the ecosystems they inhabit. As a contemporary example of high national significance for conservation, the persistence of Greater Sage-grouse (Centrocercus urophasianus) in the Great Basin is compromised by strongly interacting stressors of conifer expansion, annual grass invasion, and more frequent wildfires occurring in sagebrush ecosystems. Associated restoration treatments to a sagebrush-dominated state are often costly and may yield relatively little ecological benefit to sage-grouse if implemented without estimating how Sage-grouse may respond to treatments, or do not consider underlying processes influencing sagebrush ecosystem resilience to disturbance and resistance to invasive species. Here, we describe example applications of a spatially explicit conservation planning tool (CPT) to inform prioritization of: (1) removal of conifers (i.e., pinyon-juniper); and (2) wildfire restoration aimed at improving habitat conditions for the Bi-State Distinct Population Segment of Sage-grouse along the California-Nevada state line. The CPT measures ecological benefits to sage-grouse for a given management action through a composite index comprised of resource selection functions and estimates of abundance and space use. For pinyon-juniper removal, we simulated changes in land-cover composition following the removal of sparse trees with intact understories, and ranked treatments on the basis of changes in ecological benefits per dollar-unit of cost. For wildfire restoration, we formulated a conditional model to simulate scenarios for land cover changes (e.g., sagebrush to annual grass) given estimated fire severity and underlying ecosystem processes influencing resilience to disturbance and resistance to invasion by annual grasses. For both applications, we compared CPT rankings to land cover changes along with sagebrush

  10. Surgical outcomes of hepatocellular carcinoma invading hepatocaval confluence.

    Science.gov (United States)

    Li, Wei; Wu, Hong; Han, Jun

    2016-12-01

    Combined liver and inferior vena cava (IVC) resection followed by IVC and/or hepatic vein reconstruction (HVR) is a curative operation for selected patients with hepatocellular carcinoma (HCC) invading the hepatocaval confluence. The present study aimed to elucidate the prognostic factors for patients with HCC invading the hepatocaval confluence. Forty-two consecutive patients underwent hepatectomy, combined with IVC replacement and/or HVR for HCC between January 2009 and December 2014 were included in this study. The cases were divided into three groups based on the surgical approaches of HVR: group 1 (n=13), tumor invaded the hepatocaval confluence but with one or two hepatic veins intact in the residual liver, thus only the replacement of IVC, not HVR; group 2 (n=23), the hepatic vein of the residual liver was also partially invaded, and the hepatic vein defect was repaired with patches locally; group 3 (n=6), three hepatic veins at the hepatocaval confluence were infiltrated, and the hepatic vein remnant was re-implanted onto the side of the tube graft. The patient characteristics, intra- and postoperative results, and long-term overall survival were compared among the three groups. The survival-related factors were analyzed by univariate and multivariate analysis. The group 1 had higher preoperative alpha-fetoprotein level (PHVR (PHVR (group 1). HVR was one of the unfavorable prognostic factors of overall survival.

  11. Can Daphnia lumholtzi invade European lakes?

    Directory of Open Access Journals (Sweden)

    Meike Wittmann

    2013-03-01

    Full Text Available The cladoceran Daphnia lumholtzi is a subtropical and tropical zooplankter, and an invasive species in North America. Thus far, D. lumholtzi has not been detected in Europe. Here we investigated whether a hypothetical introduction to Europe could result in a successful invasion, either now or in the near future when facilitated by climate change. In laboratory experiments, we tested whether different clones of D. lumholtzi can invade a resident community consisting of native Daphnia from lake Klostersee, Germany, and how invasion success depends on temperature and the presence or absence of planktivorous fish. In some treatments, invasion success was consistently high, and D. lumholtzi reached densities similar to the native competitors by the end of the experiment. The presence of a planktivorous fish reduced the invasion success of D. lumholtzi, and a clone with an inducible defense against fish predation was a more successful invader than a permanently defended clone. Of the three temperatures tested in this study (15, 20, and 24 °C, invasion success was highest at 20 °C. To understand the competitive interaction between native and introduced Daphnia, we fit a Lotka-Volterra-type competition model to the population dynamics. Our experimental and modeling results suggest that D. lumholtzi can invade European lakes and can cause substantial declines in the population size of native Daphnia, with potential consequences for higher trophic levels.

  12. Metabolic characterization of invaded cells of the pancreatic cancer cell line, PANC?1

    OpenAIRE

    Fujita, Mayumi; Imadome, Kaori; Imai, Takashi

    2017-01-01

    We previously reported that about 0.4% of cells in the cultured human pancreatic cancer cell line, PANC?1, can invade matrigel during the transwell invasion assay, suggesting that these invaded PANC?1 cells may have specific characteristics to keep their invasive potential. To identify the metabolic characterization specific in the invaded PANC?1 cells, metabolome analysis of the invaded PANC?1 compared with the whole cultured PANC?1 was performed using CE?TOFMS, and concentrations of 110 met...

  13. 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.

  14. 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...

  15. How complete is our knowledge of the ecosystem services impacts of Europe's top 10 invasive species?

    Science.gov (United States)

    McLaughlan, C.; Gallardo, B.; Aldridge, D. C.

    2014-01-01

    Invasive non-native species have complex multilevel impacts on their introduced ecosystems, leading to far-ranging effects on fundamental ecosystem services, from the provision of food from that system, to human health and wellbeing. For this reason, there is an emerging interest in basing risk assessments not only on the species' ecological and economic impacts, but also on the effects related to ecosystem services. We investigated the quality and extent of baseline data detailing the effects that the top 10 of the 'worst' invasive species in Europe are having on their adopted ecosystems. The results were striking, as the 10 species showed a wide range of impacts on ecosystem services, a number of which were actually positive for ecosystems and human well-being. For instance, the bivalve Dreissena polymorpha is a prolific biofouler of pipes and boats, but it can improve water quality through its filtration of nuisance algae, a valuable effect that is often overlooked. We found that negative effects, particularly economic ones, were often assumed rather than quantitatively evidenced; for example, the cost of crop damage by species such as Myocastor coypus and Branta canadensis. In general, the evidence for impacts of these 'worst' invaders was severely lacking. We conclude that invasive species management requires prioritization, which should be based on informed and quantified assessment of the potential ecological and economic costs of species (both positive and negative), considered in the proper context of the invader and ecosystem. The Millennium Ecosystem Approach provides a useful framework to undertake such prioritization from a new perspective combining ecological and societal aspects. However, standard guidelines of evaluation are urgently needed in order to unify definitions, methods and evaluation scores.

  16. Effects of fire and restoration seeding on establishment of squarrose knapweed (Centaurea virgata var. squarrosa)

    Science.gov (United States)

    Alison Whittaker; Scott L. Jensen

    2008-01-01

    Squarrose knapweed (Centaurea virgata var. squarrosa), herein referred to simply as knapweed, is a noxious weed that invades both disturbed and healthy sagebrush communities. Fire, grazing, mining, recreation, and farming have all played a large part in the establishment of knapweed in Tintic Valley, Utah. This study was designed to look at the...

  17. 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...

  18. Co-invading symbiotic mutualists of Medicago polymorpha retain high ancestral diversity and contain diverse accessory genomes.

    Science.gov (United States)

    Porter, Stephanie S; Faber-Hammond, Joshua J; Friesen, Maren L

    2018-01-01

    Exotic, invasive plants and animals can wreak havoc on ecosystems by displacing natives and altering environmental conditions. However, much less is known about the identities or evolutionary dynamics of the symbiotic microbes that accompany invasive species. Most leguminous plants rely upon symbiotic rhizobium bacteria to fix nitrogen and are incapable of colonizing areas devoid of compatible rhizobia. We compare the genomes of symbiotic rhizobia in a portion of the legume's invaded range with those of the rhizobium symbionts from across the legume's native range. We show that in an area of California the legume Medicago polymorpha has invaded, its Ensifer medicae symbionts: (i) exhibit genome-wide patterns of relatedness that together with historical evidence support host-symbiont co-invasion from Europe into California, (ii) exhibit population genomic patterns consistent with the introduction of the majority of deep diversity from the native range, rather than a genetic bottleneck during colonization of California and (iii) harbor a large set of accessory genes uniquely enriched in binding functions, which could play a role in habitat invasion. Examining microbial symbiont genome dynamics during biological invasions is critical for assessing host-symbiont co-invasions whereby microbial symbiont range expansion underlies plant and animal invasions. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. 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...

  20. Germination responses of the invasive Calotropis procera (Ait.) R. Br. (Apocynaceae): comparisons with seeds from two ecosystems in Northeastern Brazil.

    Science.gov (United States)

    Leal, Laura C; Meiado, Marcos V; Lopes, Ariadna V; Leal, Inara R

    2013-09-01

    Life history traits are considered key indicators of plant invasibility. Among them, the germination behavior of seeds is of major relevance because it is influenced by environmental factors of invaded ecosystem. Here, we investigated how seed traits and seed tolerance to environmental factors on seed germination of Calotropis procera vary depending on the invaded ecosystems in northeastern Brazil. We have tested seeds from two vegetation types - Caatinga and Restinga - to different levels of light intensity, salinity, and water stress. Previous to those experiments, seed-set and morphometric analysis were carried out for both studied populations. We have observed a higher seed-set in Caatinga. Seeds produced in this ecosystem had lower seed moisture content. Seeds from Restinga showed lower germination time when light intensity decreased. We observed a reduction in both the germinability and the synchronization index with decreasing osmotic potential and increasing salinity. Nevertheless, both populations exhibited changes in photoblastism when seeds were submitted to water and saline stress. In conclusion, C. procera seeds are tolerant to environmental factors assessed. That characteristic ensures the colonization success and wide distribution of this plant species in the studied ecosystems.

  1. Investigating impacts of oil and gas development on greater sage-grouse

    Science.gov (United States)

    Green, Adam; Aldridge, Cameron L.; O'Donnell, Michael

    2017-01-01

    The sagebrush (Artemisia spp.) ecosystem is one of the largest ecosystems in western North America providing habitat for species found nowhere else. Sagebrush habitats have experienced dramatic declines since the 1950s, mostly due to anthropogenic disturbances. The greater sage-grouse (Centrocercus urophasianus) is a sagebrush-obligate species that has experienced population declines over the last several decades, which are attributed to a variety of disturbances including the more recent threat of oil and gas development. We developed a hierarchical, Bayesian state-space model to investigate the impacts of 2 measures of oil and gas development, and environmental and habitat conditions, on sage-grouse populations in Wyoming, USA using male lek counts from 1984 to 2008. Lek attendance of male sage-grouse declined by approximately 2.5%/year and was negatively related to oil and gas well density. We found little support for the influence of sagebrush cover and precipitation on changes in lek counts. Our results support those of other studies reporting negative impacts of oil and gas development on sage-grouse populations and our modeling approach allowed us to make inference to a longer time scale and larger spatial extent than in previous studies. In addition to sage-grouse, development may also negatively affect other sagebrush-obligate species, and active management of sagebrush habitats may be necessary to maintain some species. 

  2. Measuring landscape-scale spread and persistence of an invaded submerged plant community from airborne remote sensing.

    Science.gov (United States)

    Santos, Maria J; Khanna, Shruti; Hestir, Erin L; Greenberg, Jonathan A; Ustin, Susan L

    2016-09-01

    Processes of spread and patterns of persistence of invasive species affect species and communities in the new environment. Predicting future rates of spread is of great interest for timely management decisions, but this depends on models that rely on understanding the processes of invasion and historic observations of spread and persistence. Unfortunately, the rates of spread and patterns of persistence are difficult to model or directly observe, especially when multiple rates of spread and diverse persistence patterns may be co-occurring over the geographic distribution of the invaded ecosystem. Remote sensing systematically acquires data over large areas at fine spatial and spectral resolutions over multiple time periods that can be used to quantify spread processes and persistence patterns. We used airborne imaging spectroscopy data acquired once a year for 5 years from 2004 to 2008 to map an invaded submerged aquatic vegetation (SAV) community across 2220 km 2 of waterways in the Sacramento-San Joaquin River Delta, California, USA, and measured its spread rate and its persistence. Submerged aquatic vegetation covered 13-23 km 2 of the waterways (6-11%) every year. Yearly new growth accounted for 40-60% of the SAV area, ~50% of which survived to following year. Spread rates were overall negative and persistence decreased with time. From this dataset, we were able to identify both radial and saltatorial spread of the invaded SAV in the entire extent of the Delta over time. With both decreasing spread rate and persistence, it is possible that over time the invasion of this SAV community could decrease its ecological impact. A landscape-scale approach allows measurements of all invasion fronts and the spatial anisotropies associated with spread processes and persistence patterns, without spatial interpolation, at locations both proximate and distant to the focus of invasion at multiple points in time. © 2016 by the Ecological Society of America.

  3. 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.

  4. 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....

  5. Insects of the Idaho National Laboratory: A compilation and review

    Science.gov (United States)

    Nancy Hampton

    2005-01-01

    Large tracts of important sagebrush (Artemisia L.) habitat in southeastern Idaho, including thousands of acres at the Idaho National Laboratory (INL), continue to be lost and degraded through wildland fire and other disturbances. The roles of most insects in sagebrush ecosystems are not well understood, and the effects of habitat loss and alteration...

  6. 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...

  7. How ecosystems change following invasion by Robinia pseudoacacia: Insights from soil chemical properties and soil microbial, nematode, microarthropod and plant communities.

    Science.gov (United States)

    Lazzaro, Lorenzo; Mazza, Giuseppe; d'Errico, Giada; Fabiani, Arturo; Giuliani, Claudia; Inghilesi, Alberto F; Lagomarsino, Alessandra; Landi, Silvia; Lastrucci, Lorenzo; Pastorelli, Roberta; Roversi, Pio Federico; Torrini, Giulia; Tricarico, Elena; Foggi, Bruno

    2018-05-01

    Biological invasions are a global threat to biodiversity. Since the spread of invasive alien plants may have many impacts, an integrated approach, assessing effects across various ecosystem components, is needed for a correct understanding of the invasion process and its consequences. The nitrogen-fixing tree Robinia pseudoacacia (black locust) is a major invasive species worldwide and is used in forestry production. While its effects on plant communities and soils are well known, there have been few studies on soil fauna and microbes. We investigated the impacts of the tree on several ecosystem components, using a multi-trophic approach to combine evidence of soil chemical properties and soil microbial, nematode, microarthropod and plant communities. We sampled soil and vegetation in managed forests, comparing those dominated by black locust with native deciduous oak stands. We found qualitative and quantitative changes in all components analysed, such as the well-known soil nitrification and acidification in stands invaded by black locust. Bacterial richness was the only component favoured by the invasion. On the contrary, abundance and richness of microarthropods, richness of nematodes, and richness and diversity of plant communities decreased significantly in invaded stands. The invasion process caused a compositional shift in all studied biotic communities and in relationships between the different ecosystem components. We obtained clear insights into the effects of invasion of managed native forests by black locust. Our data confirms that the alien species transforms several ecosystem components, modifying the plant-soil community and affecting biodiversity at different levels. Correct management of this aggressive invader in temperate forests is urgently required. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Using object-based image analysis to conduct high-resolution conifer extraction at regional spatial scales

    Science.gov (United States)

    Coates, Peter S.; Gustafson, K. Benjamin; Roth, Cali L.; Chenaille, Michael P.; Ricca, Mark A.; Mauch, Kimberly; Sanchez-Chopitea, Erika; Kroger, Travis J.; Perry, William M.; Casazza, Michael L.

    2017-08-10

    The distribution and abundance of pinyon (Pinus monophylla) and juniper (Juniperus osteosperma, J. occidentalis) trees (hereinafter, "pinyon-juniper") in sagebrush (Artemisia spp.) ecosystems of the Great Basin in the Western United States has increased substantially since the late 1800s. Distributional expansion and infill of pinyon-juniper into sagebrush ecosystems threatens the ecological function and economic viability of these ecosystems within the Great Basin, and is now a major contemporary challenge facing land and wildlife managers. Particularly, pinyon-juniper encroachment into intact sagebrush ecosystems has been identified as a primary threat facing populations of greater sage-grouse (Centrocercus urophasianus; hereinafter, "sage-grouse"), which is a sagebrush obligate species. Even seemingly innocuous scatterings of isolated pinyon-juniper in an otherwise intact sagebrush landscape can negatively affect survival and reproduction of sage-grouse. Therefore, accurate and high-resolution maps of pinyon-juniper distribution and abundance (indexed by canopy cover) across broad geographic extents would help guide land management decisions that better target areas for pinyon-juniper removal projects (for example, fuel reduction, habitat improvement for sage-grouse, and other sagebrush species) and facilitate science that further quantifies ecological effects of pinyon-juniper encroachment on sage-grouse populations and sagebrush ecosystem processes. Hence, we mapped pinyon-juniper (referred to as conifers for actual mapping) at a 1 × 1-meter (m) high resolution across the entire range of previously mapped sage-grouse habitat in Nevada and northeastern California.We used digital orthophoto quad tiles from National Agriculture Imagery Program (2010, 2013) as base imagery, and then classified conifers using automated feature extraction methodology with the program Feature Analyst™. This method relies on machine learning algorithms that extract features from

  9. From effective biocontrol agent to successful invader: the harlequin ladybird (Harmonia axyridis as an example of good ideas that could go wrong

    Directory of Open Access Journals (Sweden)

    Morelia Camacho-Cervantes

    2017-05-01

    Full Text Available The use of biological control agents to control pests is an alternative to pesticides and a tool to manage invasive alien species. However, biocontrol agents can themselves become invasive species under certain conditions. The harlequin ladybird (Harmonia axyridis is a native Asian biocontrol agent that has become a successful invader. We reviewed articles containing “Harmonia axyridis” to gather information on its presence and surveyed entomologists researching Coccinellidae around the world to investigate further insights about the current distribution, vectors of introduction, habitat use and threats this species pose. The harlequin ladybird has established populations in at least 59 countries outside its native range. Twenty six percent of the surveyed scientists considered it a potential threat to native Coccinellidae. Published studies and scientists suggest Adalia bipunctata, native to Europe, is under the highest risk of population declines. Strict policies should be incorporated to prevent its arrival to non-invaded areas and to prevent further expansion range. Managing invasive species is a key priority to prevent biodiversity loss and promote ecosystem services.

  10. Diverse effects of invasive ecosystem engineers on marine biodiversity and ecosystem functions: A global review and meta-analysis.

    Science.gov (United States)

    Guy-Haim, Tamar; Lyons, Devin A; Kotta, Jonne; Ojaveer, Henn; Queirós, Ana M; Chatzinikolaou, Eva; Arvanitidis, Christos; Como, Serena; Magni, Paolo; Blight, Andrew J; Orav-Kotta, Helen; Somerfield, Paul J; Crowe, Tasman P; Rilov, Gil

    2018-03-01

    Invasive ecosystem engineers (IEE) are potentially one of the most influential types of biological invaders. They are expected to have extensive ecological impacts by altering the physical-chemical structure of ecosystems, thereby changing the rules of existence for a broad range of resident biota. To test the generality of this expectation, we used a global systematic review and meta-analysis to examine IEE effects on the abundance of individual species and communities, biodiversity (using several indices) and ecosystem functions, focusing on marine and estuarine environments. We found that IEE had a significant effect (positive and negative) in most studies testing impacts on individual species, but the overall (cumulative) effect size was small and negative. Many individual studies showed strong IEE effects on community abundance and diversity, but the direction of effects was variable, leading to statistically non-significant overall effects in most categories. In contrast, there was a strong overall effect on most ecosystem functions we examined. IEE negatively affected metabolic functions and primary production, but positively affected nutrient flux, sedimentation and decomposition. We use the results to develop a conceptual model by highlighting pathways whereby IEE impact communities and ecosystem functions, and identify several sources of research bias in the IEE-related invasion literature. Only a few of the studies simultaneously quantified IEE effects on community/diversity and ecosystem functions. Therefore, understanding how IEE may alter biodiversity-ecosystem function relationships should be a primary focus of future studies of invasion biology. Moreover, the clear effects of IEE on ecosystem functions detected in our study suggest that scientists and environmental managers ought to examine how the effects of IEE might be manifested in the services that marine ecosystems provide to humans. © 2017 John Wiley & Sons Ltd.

  11. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  13. Water and Nitrogen Limitations of Ecosystem Processes Across Three Dryland Plant Communities

    Science.gov (United States)

    Beltz, C.; Lauenroth, W. K.; Burke, I. C.

    2017-12-01

    The availability of water and nitrogen (N) play a major role in controlling the distribution of ecosystem types and the rates of ecosystem processes across the globe. Both these resources are being altered by human activity. Anthropogenic fixation of N has increased inputs into the biosphere from 0.5 kg N ha-1 yr-1 to upwards of 10 kg N ha-1 yr-1, while the amount and seasonality of precipitation are expected to continue to change. Within dryland environments, the relationships between increasingly available N and ecosystem processes are especially complex due to dryland's characteristic strong limitation by low and highly variable precipitation. Other experiments have shown that this interplay between N and water can cause temporally complex co-limitation and spatially complex responses with variable effects on ecosystems, such as those to net primary productivity, soil respiration, and plant community composition. Research spanning multiple dryland plant communities is critical for generalizing findings to the 40% of the Earth's terrestrial surface covered in dryland ecosystems. Given IPCC projections in which both N availability and precipitation are altered, examining their interactive effect across multiple plant communities is critical to increasing our understanding of the limitations to ecosystem process in drylands. We are studying a gradient of three plant communities representing a C4 grassland (shortgrass steppe), a C3/C4 grassland (mixed grass prairie), and a shrub-dominated ecosystem with C3 and C4 grasses (sagebrush steppe). We added two levels of N (10 kg N ha-1 and 100 kg N ha-1) and increased summer monthly precipitation by 20%. Sites responded differently to treatments, with the scale of effect varying by treatment. The high-level nitrogen increased soil N availability and soil respiration, while decreasing soil carbon in the labile pool in the upper soil layers. These results will allow for better understanding of increased N in combination with

  14. Invaders do not require high resource levels to maintain physiological advantages in a temperate deciduous forest.

    Science.gov (United States)

    Heberling, J Mason; Fridley, Jason D

    2016-04-01

    Non-native, invasive plants are commonly typified by trait strategies associated with high resource demands and plant invasions are often thought to be dependent upon site resource availability or disturbance. However, the invasion of shade-tolerant woody species into deciduous forests of the Eastern United States seems to contradict such generalization, as growth in this ecosystem is strongly constrained by light and, secondarily, nutrient stress. In a factorial manipulation of light and soil nitrogen availability, we established an experimental resource gradient in a secondary deciduous forest to test whether three common, woody, invasive species displayed increased metabolic performance and biomass production compared to six co-occurring woody native species, and whether these predicted differences depend upon resource supply. Using hierarchical Bayesian models of photosynthesis that included leaf trait effects, we found that invasive species exhibited functional strategies associated with higher rates of carbon gain. Further, invader metabolic and growth-related attributes were more responsive to increasing light availability than those of natives, but did not fall below average native responses even in low light. Surprisingly, neither group showed direct trait or growth responses to soil N additions. However, invasive species showed increased photosynthetic nitrogen use efficiencies with decreasing N availability, while that of natives remained constant. Although invader advantage over natives was amplified in higher resource conditions in this forest, our results indicate that some invasive species can maintain physiological advantages over co-occurring natives regardless of resource conditions.

  15. U.S. Geological Survey shrub/grass products provide new approach to shrubland monitoring

    Science.gov (United States)

    Young, Steven M.

    2017-12-11

    In the Western United States, shrubland ecosystems provide vital ecological, hydrological, biological, agricultural, and recreational services. However, disturbances such as livestock grazing, exotic species invasion, conversion to agriculture, climate change, urban expansion, and energy development are altering these ecosystems.Improving our understanding of how shrublands are distributed, where they are changing, the extent of the historical change, and likely future change directions is critical for successful management of these ecosystems. Remote-sensing technologies provide the most likely data source for large-area monitoring of ecosystem disturbance—both near-real time and historically. A monitoring framework supported by remote-sensing data can offer efficient and accurate analysis of change across a range of spatial and temporal scales.The U.S. Geological Survey has been working to develop new remote-sensing data, tools, and products to characterize and monitor these changing shrubland landscapes. Nine individual map products (components) have been developed that quantify the percent of shrub, sagebrush, big sagebrush, herbaceous, annual herbaceous, litter, bare ground, shrub height, and sagebrush height at 1-percent intervals in each 30-meter grid cell. These component products are designed to be combined and customized to widely support different applications in rangeland monitoring, analysis of wildlife habitat, resource inventory, adaptive management, and environmental review.

  16. Conservation of greater sage-grouse- a synthesis of current trends and future management

    Science.gov (United States)

    Connelly, John W.; Knick, Steven T.; Braun, Clait E.; Baker, William L.; Beever, Erik A.; Christiansen, Thomas J.; Doherty, Kevin E.; Garton, Edward O.; Hagen, Christian A.; Hanser, Steven E.; Johnson, Douglas H.; Leu, Matthias; Miller, Richard F.; Naugle, David E.; Oyler-McCance, Sara J.; Pyke, David A.; Reese, Kerry P.; Schroeder, Michael A.; Stiver, San J.; Walker, Brett L.; Wisdorn, Michael J.

    2011-01-01

    Recent analyses of Greater Sage-Grouse (Centrocercus urophasianus) populations indicate substantial declines in many areas but relatively stable populations in other portions of the species? range. Sagebrush (Artemisia spp.) habitats neces-sary to support sage-grouse are being burned by large wildfires, invaded by nonnative plants, and developed for energy resources (gas, oil, and wind). Management on public lands, which con-tain 70% of sagebrush habitats, has changed over the last 30 years from large sagebrush control projects directed at enhancing livestock grazing to a greater emphasis on projects that often attempt to improve or restore ecological integrity. Never-theless, the mandate to manage public lands to provide traditional consumptive uses as well as recreation and wilderness values is not likely to change in the near future. Consequently, demand and use of resources contained in sagebrush land-scapes plus the associated infrastructure to sup-port increasing human populations in the western United States will continue to challenge efforts to conserve Greater Sage-Grouse. The continued widespread distribution of sage-grouse, albeit at very low densities in some areas, coupled with large areas of important sagebrush habitat that are relatively unaffected by the human footprint, sug-gest that Greater Sage-Grouse populations may be able to persist into the future. We summarize the status of sage-grouse populations and habitats, provide a synthesis of major threats and chal-lenges to conservation of sage-grouse, and suggest a roadmap to attaining conservation goals.

  17. 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, 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

  18. 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

  19. Current ecosystem processes in steppe near Lake Baikal

    Science.gov (United States)

    Vanteeva, Julia

    2015-04-01

    The steppes and forest steppes complexes of Priol'khonie at the Lake Baikal (southern Siberia, Russia) were studied in this research. Recreational activity has a significant impact on the Priol'khonie region. During soviet time this area was actively used for agriculture. Nowadays, this territory is the part of Pribaikalskyi National Park and special protection is needed. As the landscapes satisfy different human demands there are many land-management conflicts. The specific climate and soil conditions and human activity lead to erosion processes on study area. Sediment loads are transferred into the Lake Baikal and cause water pollution. Consequently, vegetation cover and phytomass play an important role for regulating hydrological processes in the ecosystems. The process of phytomass formation and its proactive role playing on sedimentation and mitigate silt detaching by rill and inter-rill erosion are considered in the research as important indicators of the ecosystem functions for steppe landscapes. These indicators were studied for the different land cover types identified on the area because the study area has a large variety of steppe and forest steppe complexes, differing in the form of relief, soil types, vegetation species composition and degree of land degradation. The fieldwork was conducted in the study area in the July and August of 2013. Thirty-two experimental sites (10 x 10 m) which characterized different types of ecosystem were established. The level of landscape degradation was estimated. The method of clipping was used for the valuation of above-ground herbaceous phytomass. The phytomass of tree stands was calculated using the volume-conversion rates for forest-steppe complexes. For the quantification of transferred silt by inter-rill erosion in different conditions (vegetation, slope, soil type, anthropogenic load) a portable rainfall simulator was created with taking into account the characteristics of the study area. The aboveground

  20. Predicting the spread of aquatic invaders: insight from 200 years of invasion by zebra mussels.

    Science.gov (United States)

    Karatayev, Alexander Y; Burlakova, Lyubov E; Mastitsky, Sergey E; Padilla, Dianna K

    2015-03-01

    Understanding factors controlling the introduction and spread of species is crucial to improving the management of both natural populations and introduced species. The zebra mussel, Dreissena polymorpha, is considered the most aggressive freshwater invader in the Northern Hemisphere, and is a convenient model system for invasion biology, offering one of the best aquatic examples for examining the invasion process. We used data on 553 of the 1040 glacial lakes in the Republic of Belarus that were examined for the presence of zebra mussels. We used these data to build, test, and construct modified models to predict the spread of this invader, including selection of important parameters that could limit the spread of this invader. In spite of 200 years of continuous invasion, by 1996, zebra mussels were found in only 16.8% of all lakes studied. Of those lakes without zebra mussels in 1996, 66% were predicted to be susceptible to invasion by zebra mussels in the future, and 33% were predicted to be immune to successful invasion due to their water chemistry. Eighty lakes free of zebra mussels in 1996 were reexamined from 1997 to 2008. Of these, zebra mussels successfully invaded an additional 31 lakes, all of which were classified initially as suitable for zebra mussels; none of the lakes previously classified as unsuitable were invaded. We used the Random Forests classification algorithm with 16 environmental variables to determine the most important factors that differed between invaded lakes and those lakes suitable for invasion that have not yet been invaded. Distance to the nearest infested lakes was found to be the most important variable, followed by the lake area, color, average depth, and concentration of chloride, magnesium, and bicarbonate. This study provides a useful approach for predicting the spread of an invader across a landscape with variable habitat suitability that can be applied to a variety of species and systems.

  1. Avian wildlife as sentinels of ecosystem health.

    Science.gov (United States)

    Smits, Judit E G; Fernie, Kimberly J

    2013-05-01

    Birds have been widely used as sentinels of ecosystem health reflecting changes in habitat quality, increased incidence of disease, and exposure to and effects of chemical contaminants. Numerous studies addressing these issues focus on the breeding period, since hormonal, behavioural, reproductive, and developmental aspects of the health can be observed over a relatively short time-span. Many body systems within individuals are tightly integrated and interdependent, and can be affected by contaminant chemicals, disease, and habitat changes in complex ways. Animals higher in the food web will reflect cumulative effects of multiple stressors. Such features make birds ideal indicators for assessing environmental health in areas of environmental concern. Five case studies are presented, highlighting the use of different species which have provided insight into ecosystem sustainability, including (i) the consequences of anthropogenic disturbances of sagebrush habitat on the greater northern sage grouse Centrocercus urophasianus; (ii) the high prevalence of disease in very specific passerine species in the Canary Islands closely paralleling deterioration of formerly productive desert habitat and ensuing interspecific stressors; (iii) fractures, abnormal bone structure, and associated biochemical aberrations in nestling storks exposed to acidic tailings mud from a dyke rupture at an iron pyrite mine near Sevilla, Spain; (iv) newly presented data demonstrating biochemical changes in nestling peregrine falcons Falco peregrinus and associations with exposure to major chemical classes in the Great Lakes Basin of Canada; and (v) the variability in responses of tree swallows Tachycineta bicolor to contaminants, biological and meteorological challenges when breeding in the Athabasca oil sands. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Economic assessment of the contribution of biological control to the management of invasive alien plants and to the protection of ecosystem services in South Africa

    CSIR Research Space (South Africa)

    De Lange, Willem J

    2010-07-01

    Full Text Available This study is a first attempt at a holistic economic evaluation of South African endeavours to manage invasive alien plants using biological control. The author’s focus was on the delivery of ecosystem services from habitats that are invaded...

  3. Brown trout as an invader: A synthesis of problems and perspectives in western North America: Chapter 20

    Science.gov (United States)

    Budy, Phaedra; Gaeta, Jereme W.; Lobón-Cerviá, Javier; Sanz, Nuria

    2017-01-01

    Brown trout are one of the most pervasive and successful invaders worldwide and are ubiquitous across the Intermountain West, USA (IMW). This species is the foundation of extremely popular and economically significant sport fisheries despite well-established negative effects on native fishes and ecosystems, resulting in very challenging, and often opposing, conservation and management goals. Herein, we review the direct (e.g., competition and predation) and indirect (e.g., disease vectors) pathways through which brown trout across the IMW have posed a threat to native species. We discuss the importance of brown trout as economically and culturally important fisheries, especially in novel tailwater ecosystems created by damming. To this end, we surveyed 24 experts from eight states across the IMW to document the relevance of novel brown trout fisheries in 51 tailwaters and found brown trout are thriving in these novel ecosystems, which are often unsuitable for native fishes. We discuss the challenging interplay between protecting native species and managing novel brown trout fisheries. Notably, the future of exotic brown trout in the IMW is shifting as the prestige of native fisheries is growing and many non-native eradication efforts have occurred. The future of exotic brown trout in the IMW, will depend on the nexus of public sentiment and policy, the effectiveness of eradication efforts, and the effect of climate change on both the native fishes and exotic brown trout. Regardless, because brown trout are pervasive and have a broad distribution through the IMW, populations of this species will likely persist at least in some locations into the future.

  4. Biological invasion by Myrica faya in Hawaii: Plant demography, nitrogen fixation, ecosystem effects

    International Nuclear Information System (INIS)

    Vitousek, P.M.; Walker, L.R.

    1989-01-01

    Myrica faya, an introduced actinorhizal nitrogen fixer, in invading young volcanic sites in Hawaii Volcanoes National Park. We examined the population biology of the invader and ecosystem-level consequences of its invasion in open-canopied forests resulting from volcanic cinder-fall. Although Myrica faya is nominally dioecious, both males and females produce large amounts of fruit that are utilized by a number of exotic and native birds, particularly the exotic Zosterops japonica. In areas of active colonization, Myrica seed rain under perch trees of the dominant native Metrosideros polymorpha ranged from 6 to 60 seeds m -2 yr -1 ; no seeds were captured in the open. Planted seeds of Myrica also germinated an established better under isolated individuals of Metrosideros than in the open. Diameter growth of Myrica is > 15-fold greater than that of Metrosideros, and the Myrica population is increasing rapidly. Rates of nitrogen fixation were measured using the acetylene reduction assay calibrated with 15 N. Myrica nodules reduced acetylene at between 5 and 20 μmol g -1 h -1 , a rate that extrapolated to nitrogen fixation of 18 kg ha -1 in a densely colonized site. By comparison, all native sources of nitrogen fixation summed to 0.2 kg ha -1 yr -1 , and precipitation added -1 yr -1 . Measurements of litter decomposition and nitrogen release, soil nitrogen mineralization, and plant growth in bioassays all demonstrated that nitrogen fixed by Myrica becomes available to other organisms as well. We conclude that biological invasion by Myrica faya alters ecosystem-level properties in this young volcanic area; at least in this case, the demography and physiology of one species controls characteristics of a whole ecosystem

  5. Hepatocellular carcinoma directly invading the duodenum

    International Nuclear Information System (INIS)

    Mohamed, Abdelrehman O.; Joshi, Sandhya; Czechowski, Janusz; Branicki, Frank

    2005-01-01

    Recurrent gastrointestinal bleeding from hepatocellular carcinoma (HCC) invading the duodenum is very rare. We present a case of 50-year-old male who was admitted with a history of recurrent upper gastrointestinal tract (UGIT) bleeding, weight loss and anemia. The patient was known to have a chronic hepatitis C. Endoscopic examination showed grade-2 non-bleeding esophageal varices, and a large ulcerated duodenal mass partially obstructing the duodenal bulb outlet and causing recurrent UGIT bleeding. Pathological evaluation of the mass revealed HCC. (author)

  6. Red Lionfish (Pterois volitans Invade San Salvador, Bahamas: No Early Effects on Coral and Fish Communities

    Directory of Open Access Journals (Sweden)

    Alexander, Amanda K.

    2011-10-01

    Full Text Available Biological invaders are a leading contributor to global losses of biodiversity. A recent invader to the waters surrounding San Salvador, Bahamas, the red lionfish, Pterois volitans, was first reported in 2006; by 2009 they were common in waters 2-40 m deep around the island. Our study collected data on coral communities and fish assemblages at three patch reef complexes (Rice Bay, Rocky Point, Lindsay Reef in 2007, during the initial phase of the invasion, and compared the results to a nearly identical study done in 2001 before P. volitans colonized San Salvador. Prey selection and quantity of consumption by P. volitans were also examined. Coral and fish species richness, diversity, percent cover (corals and abundance (fish were similar in 2001 and 2007. Of the 5,078 fish recorded during our study on shallow patch reefs, only two were P. volitans, but they were more prevalent in deeper water along San Salvador’s “wall.” Captured P. volitans ranged in size from 19-32 cm, all longer than maturity length. Pallid goby (Coryphopterus eidolon, black cap basslet (Gramma melacara and red night shrimp (Rynchocienetes rigens were the most commonly identified stomach contents. The effects of the successful invasion and increasing population of P. volitans on San Salvador’s reef ecosystem are uncertain at this time; future monitoring of potential changes in coral and fish communities on the patch reefs of San Salvador is recommended to determine if population control measures need to be considered. Initial post-invasion data (2007, along with pre-invasion data (2001, are valuable benchmarks for future studies.

  7. Enhancing early detection of exotic pests in agricultural and forest ecosystems using an urban-gradient framework.

    Science.gov (United States)

    Colunga-Garcia, Manuel; Magarey, Roger A; Haack, Robert A; Gage, Stuart H; Qi, Jiaquo

    2010-03-01

    Urban areas are hubs of international transport and therefore are major gateways for exotic pests. Applying an urban gradient to analyze this pathway could provide insight into the ecological processes involved in human-mediated invasions. We defined an urban gradient for agricultural and forest ecosystems in the contiguous United States to (1) assess whether ecosystems nearer more urbanized areas were at greater risk of invasion, and (2) apply this knowledge to enhance early detection of exotic pests. We defined the gradient using the tonnage of imported products in adjacent urban areas and their distance to nearby agricultural or forest land. County-level detection reports for 39 exotic agricultural and forest pests of major economic importance were used to characterize invasions along the gradient. We found that counties with more exotic pests were nearer the urban end of the gradient. Assuming that the exotic species we analyzed represent typical invaders, then early detection efforts directed at 21-26% of U.S. agricultural and forest land would likely be able to detect 70% of invaded counties and 90% of the selected species. Applying an urban-gradient framework to current monitoring strategies should enhance early detection efforts of exotic pests, facilitating optimization in allocating resources to areas at greater risk of future invasions.

  8. Native birds and alien insects: spatial density dependence in songbird predation of invading oak gallwasps.

    Directory of Open Access Journals (Sweden)

    Karsten Schönrogge

    Full Text Available Revealing the interactions between alien species and native communities is central to understanding the ecological consequences of range expansion. Much has been learned through study of the communities developing around invading herbivorous insects. Much less, however, is known about the significance of such aliens for native vertebrate predators for which invaders may represent a novel food source. We quantified spatial patterns in native bird predation of invading gall-inducing Andricus wasps associated with introduced Turkey oak (Quercus cerris at eight sites across the UK. These gallwasps are available at high density before the emergence of caterpillars that are the principle spring food of native insectivorous birds. Native birds showed positive spatial density dependence in gall attack rates at two sites in southern England, foraging most extensively on trees with highest gall densities. In a subsequent study at one of these sites, positive spatial density dependence persisted through four of five sequential week-long periods of data collection. Both patterns imply that invading galls are a significant resource for at least some native bird populations. Density dependence was strongest in southern UK bird populations that have had longest exposure to the invading gallwasps. We hypothesise that this pattern results from the time taken for native bird populations to learn how to exploit this novel resource.

  9. Saddam Hussein's Decision to Invade Kuwait - Where Was Plan B

    National Research Council Canada - National Science Library

    Culpepper, Frances R

    1997-01-01

    ... in his decision to invade Kuwait in August 1990 Surveying the damage to the Iraqi economy following the Iran-Iraq war, Saddam knew that insufficient resources would force hum to shelve any domestic program...

  10. An Ecosystem-Service Approach to Evaluate the Role of Non-Native Species in Urbanized Wetlands

    Science.gov (United States)

    Yam, Rita S. W.; Huang, Ko-Pu; Hsieh, Hwey-Lian; Lin, Hsing-Juh; Huang, Shou-Chung

    2015-01-01

    Natural wetlands have been increasingly transformed into urbanized ecosystems commonly colonized by stress-tolerant non-native species. Although non-native species present numerous threats to natural ecosystems, some could provide important benefits to urbanized ecosystems. This study investigated the extent of colonization by non-native fish and bird species of three urbanized wetlands in subtropical Taiwan. Using literature data the role of each non-native species in the urbanized wetland was evaluated by their effect (benefits/damages) on ecosystem services (ES) based on their ecological traits. Our sites were seriously colonized by non-native fishes (39%–100%), but wetland ES. Our results indicated the importance of non-native fishes in supporting ES by serving as food source to fish-eating waterbirds (native, and migratory species) due to their high abundance, particularly for Oreochromis spp. However, all non-native birds are regarded as “harmful” species causing important ecosystem disservices, and thus eradication of these bird-invaders from urban wetlands would be needed. This simple framework for role evaluation of non-native species represents a holistic and transferable approach to facilitate decision making on management priority of non-native species in urbanized wetlands. PMID:25860870

  11. Distinguishing neuroblastoma invading the kidney from nephroblastoma: evaluation in computed tomography

    International Nuclear Information System (INIS)

    Qiao Zhongwei; Li Guoping; Mamier; Wang Kang'an; Lv Zhibao; Miao Fei

    2005-01-01

    Objective: To evaluate the CT findings in the differential diagnosis between neuroblastoma invading the kidney and nephroblastoma. Methods: CT morphologic details in 13 patients with neuroblastoma invading the kidney confirmed by surgical operation and pathology were studied, and CT findings in 15 patients with nephroblastoma confirmed by surgery and pathology were compared. Results: In 13 cases of neuroblastoma, CT showed irregular mass in 12 cases, tumor with poorly defined margins in 11 cases, tumorous calcifications in 10 cases, invasion of retroperitoneal vessels in 9 cases, and retroperitoneal and retrocrural lymph nodes invasion in 12 cases. In 15 cases of nephroblastoma, round mass was p resented in 12 cases, tumor with poorly defined margins in 2 cases, tumorous calcifications in 2 cases, involvement of retroperitoneal vessels in 2 cases, and invasion of retroperitoneal lymph nodes in 3 cases. None of the nephroblastoma invaded retrocrural lymph nodes. Irregular mass with calcifications, involvement of retroperitoneal vessels, retrocrural and retroperitoneal lymph nodes were more common in cases of neuroblastoma than in nephroblastoma. Moreover, involvement of retrocrural lymph nodes and encasement of retroperitoneal vessels had higher positive prediction value on neuroblastoma. Conclusion: Involvement of retrocrural lymph nodes and encasement of retroperitoneal vessels were the specific CT findings of neuroblastoma and the most valuable evidence in distinguishing neuroblastoma from nephroblastoma. (authors)

  12. Deja vu? A second mytilid mussel, Semimytilus algosus , invades ...

    African Journals Online (AJOL)

    A second marine mussel is shown to have invaded South Africa's west coast. Molecular techniques, based on intraspecific gene sequence divergences, prove its identity as Semimytilus algosus, a member of the family Mytilidae, native to Chile. The identity of an older introduced population found in Namibia is also ...

  13. Scaling the consequences of interactions between invaders from the individual to the population level.

    Science.gov (United States)

    Griffen, Blaine D

    2016-03-01

    The impact of human-induced stressors, such as invasive species, is often measured at the organismal level, but is much less commonly scaled up to the population level. Interactions with invasive species represent an increasingly common source of stressor in many habitats. However, due to the increasing abundance of invasive species around the globe, invasive species now commonly cause stresses not only for native species in invaded areas, but also for other invasive species. I examine the European green crab Carcinus maenas, an invasive species along the northeast coast of North America, which is known to be negatively impacted in this invaded region by interactions with the invasive Asian shore crab Hemigrapsus sanguineus. Asian shore crabs are known to negatively impact green crabs via two mechanisms: by directly preying on green crab juveniles and by indirectly reducing green crab fecundity via interference (and potentially exploitative) competition that alters green crab diets. I used life-table analyses to scale these two mechanistic stressors up to the population level in order to examine their relative impacts on green crab populations. I demonstrate that lost fecundity has larger impacts on per capita population growth rates, but that both predation and lost fecundity are capable of reducing population growth sufficiently to produce the declines in green crab populations that have been observed in areas where these two species overlap. By scaling up the impacts of one invader on a second invader, I have demonstrated that multiple documented interactions between these species are capable of having population-level impacts and that both may be contributing to the decline of European green crabs in their invaded range on the east coast of North America.

  14. 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

    Science.gov (United States)

    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.

  15. Evaluation of the Steel Creek ecosystem in relation to the proposed restart of the L-reactor

    International Nuclear Information System (INIS)

    Smith, M.H.; Sharitz, R.R.; Gladden, J.B.

    1982-10-01

    This report summarizes the findings of slightly more than one year's study of the Steel Creek ecosystem. Generally, the findings have allowed us to refine our understanding of the structural and functional organization of the Steel Creek ecosystem which is an essential prerequisite for predicting the impacts associated with L-reactor restart. Reanalysis of the Steel Creek plant community relationships using 1981 aerial photography revealed that this component of the delta ecosystem continues to change as a result of natural successional processes. The major detectable changes have occurred on the more elevated portions of Steel Creek delta where coverage by woody species (especially willow) is continuing to increase. This successional woody community is invading areas previously dominated by persistent herbaceous species such as cut grass. Eleven vegetation associations were identified in the Steel Creek delta area, including two associations that were not apparently affected by the earlier reactor operations

  16. Assessment of insect invaders of decaying banana and plantain ...

    African Journals Online (AJOL)

    Insect invaders of decaying banana and plantain pseudo stems in Umuagwo, Ohaji-Egbema, Imo State were investigated in randomly selected crop plots near living homes (<500 m) and far from living homes (.500m). Investigation was done by the use of trapping systems, dissections of cut decaying pseudo stems and ...

  17. Patterns of seed dispersal and establishment of the invader ...

    African Journals Online (AJOL)

    Invasive species in Africa have important impacts on food security and biodiversity conservation. African floodplains in arid areas are critical wildlife habitats in addition to crop production and dry season livestock grazing. The study aimed to understand the patterns of spread of the invader Prosopis juliflora in a typical ...

  18. 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.

  19. Prospects for extirpating small populations of the wetland invader ...

    African Journals Online (AJOL)

    The broad-leaved paper bark tree Melaleuca quinquenervia is a major invader in the wetlands of the Florida Everglades, USA. In South Africa, this introduced species is known from eight locality records and is naturalising at two of these sites. The potential for its spread to other wetlands and estuaries is of concern.

  20. Habitat shift in invading species: Zebra and quagga mussel population characteristics on shallow soft substrates

    Science.gov (United States)

    Berkman, P.A.; Garton, D.W.; Haltuch, M.A.; Kennedy, G.W.; Febo, L.R.

    2000-01-01

    Unexpected habitat innovations among invading species are illustrated by the expansion of dreissenid mussels across sedimentary environments in shallow water unlike the hard substrates where they are conventionally known. In this note, records of population characteristics of invading zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussels from 1994 through 1998 are reported from shallow (less than 20 m) sedimentary habitats in western Lake Erie. Haphazard SCUBA collections of these invading species indicated that combined densities of zebra and quagga mussels ranged from 0 to 32,500 individuals per square meter between 1994 and 1998, with D. polymorpha comprising 75-100% of the assemblages. These mixed mussel populations, which were attached by byssal threads to each other and underlying sand-grain sediments, had size-frequency distributions that were typical of colonizing populations on hard substrates. Moreover, the presence of two mussel cohorts within the 1994 samples indicated that these species began expanding onto soft substrates not later than 1992, within 4 years of their initial invasion in western Lake Erie. Such historical data provide baselines for interpreting adaptive innovations, ecological interactions and habitat shifts among the two invading dreissenid mussel species in North America.

  1. Invasive ecosystem engineer selects for different phenotypes of an associated native species.

    Science.gov (United States)

    Wright, Jeffrey T; Gribben, Paul E; Byers, James E; Monro, Keyne

    2012-06-01

    Invasive habitat-forming ecosystem engineers modify the abiotic environment and thus represent a major perturbation to many ecosystems. Because native species often persist in these invaded habitats but have no shared history with the ecosystem engineer, the engineer may impose novel selective pressure on native species. In this study, we used a phenotypic selection framework to determine whether an invasive habitat-forming ecosystem engineer (the seaweed Caulerpa taxifolia) selects for different phenotypes of a common co-occurring native species (the bivalve Anadara trapezia). Compared to unvegetated habitat, Caulerpa habitat has lower water flow, lower dissolved oxygen, and sediments are more silty and anoxic. We determined the performance consequences of variation in key functional traits that may be affected by these abiotic changes (shell morphology, gill mass, and palp mass) for Anadara transplanted into Caulerpa and unvegetated habitat. Both linear and nonlinear performance gradients in Anadara differed between habitats, and these gradients were stronger in Caulerpa compared to unvegetated sediment. Moreover, in Caulerpa alternate phenotypes performed well, and these phenotypes were different from the dominant phenotype in unvegetated sediment. By demonstrating that phenotype-performance gradients differ between habitats, we have highlighted a role for Caulerpa as an agent of selection on native species.

  2. 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.

  3. Total or partial vertebrectomy for lung cancer invading the spine

    Directory of Open Access Journals (Sweden)

    Soichi Oka

    2016-12-01

    Conclusions: In our experience, Lung cancer surgery combined with vertebrectomy is highly aggressive surgery associated with high morbidity. But, this procedure is a promising treatment option for selected patients, for example N0M0 disease with lung cancer invading the spine.

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

    Science.gov (United States)

    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...

  5. MicroEcos: Micro-Scale Explorations of Large-Scale Late Pleistocene Ecosystems

    Science.gov (United States)

    Gellis, B. S.

    2017-12-01

    Pollen data can inform the reconstruction of early-floral environments by providing data for artistic representations of what early-terrestrial ecosystems looked like, and how existing terrestrial landscapes have evolved. For example, what did the Bighorn Basin look like when large ice sheets covered modern Canada, the Yellowstone Plateau had an ice cap, and the Bighorn Mountains were mantled with alpine glaciers? MicroEcos is an immersive, multimedia project that aims to strengthen human-nature connections through the understanding and appreciation of biological ecosystems. Collected pollen data elucidates flora that are visible in the fossil record - associated with the Late-Pleistocene - and have been illustrated and described in botanical literature. It aims to make scientific data accessible and interesting to all audiences through a series of interactive-digital sculptures, large-scale photography and field-based videography. While this project is driven by scientific data, it is rooted in deeply artistic and outreach-based practices, which include broad artistic practices, e.g.: digital design, illustration, photography, video and sound design. Using 3D modeling and printing technology MicroEcos centers around a series of 3D-printed models of the Last Canyon rock shelter on the Wyoming and Montana border, Little Windy Hill pond site in Wyoming's Medicine Bow National Forest, and Natural Trap Cave site in Wyoming's Big Horn Basin. These digital, interactive-3D sculpture provide audiences with glimpses of three-dimensional Late-Pleistocene environments, and helps create dialogue of how grass, sagebrush, and spruce based ecosystems form. To help audiences better contextualize how MicroEcos bridges notions of time, space, and place, modern photography and videography of the Last Canyon, Little Windy Hill and Natural Trap Cave sites surround these 3D-digital reconstructions.

  6. Physical, Chemical, Ecological, and Age Data and Trench Logs from Surficial Deposits at Hatch Point, Southeastern Utah

    Science.gov (United States)

    Goldstein, Harland L.; Miller, Mark E.; Yount, James C.; Reheis, Marith C.; Reynolds, Richard L.; Belnap, Jayne; Lamothe, Paul J.; McGeehan, John P.

    2009-01-01

    This report presents data and describes the methodology for physical, chemical and ecological measurements of sediment, soil, and vegetation, as well as age determinations of surficial deposits at Hatch Point, Canyon Rims area, Colorado Plateau, southeastern Utah. The results presented in this report support a study that examines geomorphic and soil factors that may influence boundaries between shrubland and grassland ecosystems in the study area. Shrubland ecosystems dominated by sagebrush (Artemisia tridentata) and grassland ecosystems dominated by native perennial grasses (for example, Hilaria jamesii and Sporabolis sp.) are high-priority conservation targets for the Federal Bureau of Land Management (BLM) and other resource managers because of their diversity, productivity, and vital importance as wildlife habitat. These ecosystems have been recognized as imperiled on a regional scale since at least the mid-1990s due to habitat loss (type conversions), land-use practices, and invasive exotic plants. In the Intermountain West, the exotic annual cheatgrass (Bromus tectorum) is recognized as one of the most pervasive and serious threats to the health of native sagebrush and grassland ecosystems through effects on fire regimes and resource conditions experienced by native species.

  7. The importance of the human footprint in shaping the global distribution of terrestrial, freshwater and marine invaders.

    Directory of Open Access Journals (Sweden)

    Belinda Gallardo

    Full Text Available Human activities such as transport, trade and tourism are likely to influence the spatial distribution of non-native species and yet, Species Distribution Models (SDMs that aim to predict the future broad scale distribution of invaders often rely on environmental (e.g. climatic information only. This study investigates if and to what extent do human activities that directly or indirectly influence nature (hereafter the human footprint affect the global distribution of invasive species in terrestrial, freshwater and marine ecosystems. We selected 72 species including terrestrial plants, terrestrial animals, freshwater and marine invasive species of concern in a focus area located in NW Europe (encompassing Great Britain, France, The Netherlands and Belgium. Species Distribution Models were calibrated with the global occurrence of species and a set of high-resolution (9×9 km environmental (e.g. topography, climate, geology layers and human footprint proxies (e.g. the human influence index, population density, road proximity. Our analyses suggest that the global occurrence of a wide range of invaders is primarily limited by climate. Temperature tolerance was the most important factor and explained on average 42% of species distribution. Nevertheless, factors related to the human footprint explained a substantial amount (23% on average of species distributions. When global models were projected into the focus area, spatial predictions integrating the human footprint featured the highest cumulative risk scores close to transport networks (proxy for invasion pathways and in habitats with a high human influence index (proxy for propagule pressure. We conclude that human related information-currently available in the form of easily accessible maps and databases-should be routinely implemented into predictive frameworks to inform upon policies to prevent and manage invasions. Otherwise we might be seriously underestimating the species and areas under

  8. Invasion of a Legume Ecosystem Engineer in a Cold Biome Alters Plant Biodiversity

    Directory of Open Access Journals (Sweden)

    Vanessa M. S. Vetter

    2018-06-01

    Full Text Available Plant ecosystem engineers are widely used to combat land degradation. However, the ability of those plants to modulate limiting abiotic and biotic resources of other species can cause damage to ecosystems in which they become invasive. Here, we use Lupinus nootkatensis as example to estimate and project the hazardous potential of nitrogen fixing herbaceous plants in a sub-polar oceanic climate. L. nootkatensis was introduced to Iceland in the 1940s to address erosion problems and foster reforestation, but subsequently became a high-latitude invader. In a local field survey, we quantified the impact of L. nootkatensis invasion at three different cover levels (0, 10–50, and 51–100% upon native plant diversity, richness, and community composition of heath-, wood-, and grasslands using a pairwise comparison design and comparisons of means. Afterward, we scaled impacts up to the ecosystem and landscape level by relating occurrences of L. nootkatensis to environmental and human-mediated variables across Iceland using a species distribution model. Plant diversity was significantly deteriorated under high lupine cover levels of the heath- and woodland, but not in the grassland. Plant species richness of the most diverse habitat, the heathland, linearly decreased with lupine cover level. The abundance of small rosettes, cushion plants, orchids, and small woody long-lived plants of the heath declined with invader presence, while the abundance of late successional species and widespread nitrophilous ruderals in wood- and grasslands increased. Distribution modeling revealed 13.3% of Iceland’s land surface area to be suitable lupine habitat. Until 2061–2080, this area will more than double and expand significantly into the Central Highlands due to human mediation and increasingly favorable climatic conditions. Species-rich habitats showed a loss of plant species diversity and richness as well as a change in community composition even in low lupine

  9. The effect of Piper aduncum invasion on soil in tropical ecosystems of Papua New Guinea

    Science.gov (United States)

    Kukla, Jaroslav; Frouz, Jan

    2017-04-01

    Piper aduncum is successful Neotropical invasive species in Papua New Guinea. Despite its interaction with aboveground part of ecosystem has been extensively studied little is known about its effect on soil. Here we report two studies, in first we compare soil chemistry and soil biota in sites invaded and non-invaded by P. aduncum near Wanang village. In other study we use benefit of previous experiment when P. aduncum was experimentally removed near Ohu village. Here we compare soil chemistry and chemistry of plant leaves growing in garden originating by slashing and burning two adjacent patches with and without P. aduncum. Soil under P. aduncum had significantly less phosphorus in 0-5 cm soil layer and less nitrates, nitrogen and carbon in 5-10 cm soil layer than soil in old gardens uninvaded by P. aduncum. P. aduncum soil also harbors fewer microfloras than uninvaded soil as shown by PLFA analysis. No difference was found in fauna communities. Gardens created on patches where old P. aduncum was removed did not differ in soil chemistry from plots which were overgrown by P. aduncum, but leaves of sweet potatoes (Ipomoea batatas) in gardens where P. aduncum was previously removed contained more nitrogen. Results suggest that P. aduncum invasion may affect some chemical and microbial properties in invaded soil. P. aduncum has negative effect on traditional shifting agriculture.

  10. REFLECTIONS ON POVERTY SOLUTIONS OFFERED BY INTRODUCING SOCIAL ENTREPRENEURSHIP TO ECOSYSTEM SERVICES

    Directory of Open Access Journals (Sweden)

    GABRIELA PRELIPCEAN

    2016-06-01

    Full Text Available The new economy which characterizes today’s world is invaded by countless theories and concepts which try to explain the way societies fail to assure a general well-being for citizens and wish to offer support for the development of a flourishing and safe future. Between these concepts, some new and some old, are the social entrepreneurship and the ecosystem services. Both of these have started to become very important for researchers and policy makers in the last decade. Also, both have the objective of creating a more human economy and assuring the human well-being. Even though the subjects of these theories are very different, we have managed to show in this paper that a correlation between the two is possible and more than that their combination can have positive outcomes. Social entrepreneurship is a concept describing a new way of using business know-how gained from the private sector in order to find solutions to social, cultural and environmental problems. Ecosystem services are the benefits which people obtain from ecosystems. A relation between the two concepts can be represented by the fact that ecosystem services might be the subject of social entrepreneurship. Another one would be the input which social entrepreneurship might bring to ecosystem services, in what concerns abilities and techniques in dealing with different problems. In conclusion, we tried to show that these double way relations would have an important role in what concerns the fight against poverty.

  11. Impacts of invading alien plant species on water flows at stand and catchment scales

    Science.gov (United States)

    Le Maitre, D. C.; Gush, M. B.; Dzikiti, S.

    2015-01-01

    There have been many studies of the diverse impacts of invasions by alien plants but few have assessed impacts on water resources. We reviewed the information on the impacts of invasions on surface runoff and groundwater resources at stand to catchment scales and covering a full annual cycle. Most of the research is South African so the emphasis is on South Africa's major invaders with data from commercial forest plantations where relevant. Catchment studies worldwide have shown that changes in vegetation structure and the physiology of the dominant plant species result in changes in surface runoff and groundwater discharge, whether they involve native or alien plant species. Where there is little change in vegetation structure [e.g. leaf area (index), height, rooting depth and seasonality] the effects of invasions generally are small or undetectable. In South Africa, the most important woody invaders typically are taller and deeper rooted than the native species. The impacts of changes in evaporation (and thus runoff) in dryland settings are constrained by water availability to the plants and, thus, by rainfall. Where the dryland invaders are evergreen and the native vegetation (grass) is seasonal, the increases can reach 300–400 mm/year. Where the native vegetation is evergreen (shrublands) the increases are ∼200–300 mm/year. Where water availability is greater (riparian settings or shallow water tables), invading tree water-use can reach 1.5–2.0 times that of the same species in a dryland setting. So, riparian invasions have a much greater impact per unit area invaded than dryland invasions. The available data are scattered and incomplete, and there are many gaps and issues that must be addressed before a thorough understanding of the impacts at the site scale can be gained and used in extrapolating to watershed scales, and in converting changes in flows to water supply system yields. PMID:25935861

  12. Impacts of invading alien plant species on water flows at stand and catchment scales.

    Science.gov (United States)

    Le Maitre, D C; Gush, M B; Dzikiti, S

    2015-05-01

    There have been many studies of the diverse impacts of invasions by alien plants but few have assessed impacts on water resources. We reviewed the information on the impacts of invasions on surface runoff and groundwater resources at stand to catchment scales and covering a full annual cycle. Most of the research is South African so the emphasis is on South Africa's major invaders with data from commercial forest plantations where relevant. Catchment studies worldwide have shown that changes in vegetation structure and the physiology of the dominant plant species result in changes in surface runoff and groundwater discharge, whether they involve native or alien plant species. Where there is little change in vegetation structure [e.g. leaf area (index), height, rooting depth and seasonality] the effects of invasions generally are small or undetectable. In South Africa, the most important woody invaders typically are taller and deeper rooted than the native species. The impacts of changes in evaporation (and thus runoff) in dryland settings are constrained by water availability to the plants and, thus, by rainfall. Where the dryland invaders are evergreen and the native vegetation (grass) is seasonal, the increases can reach 300-400 mm/year. Where the native vegetation is evergreen (shrublands) the increases are ∼200-300 mm/year. Where water availability is greater (riparian settings or shallow water tables), invading tree water-use can reach 1.5-2.0 times that of the same species in a dryland setting. So, riparian invasions have a much greater impact per unit area invaded than dryland invasions. The available data are scattered and incomplete, and there are many gaps and issues that must be addressed before a thorough understanding of the impacts at the site scale can be gained and used in extrapolating to watershed scales, and in converting changes in flows to water supply system yields. Published by Oxford University Press on behalf of the Annals of Botany

  13. 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.

  14. Propagule pressure, genetic structure, and geographic origins of Chondrilla juncea (Asteraceae): an apomictic invader on three continents.

    Science.gov (United States)

    Gaskin, John F; Schwarzländer, Mark; Kinter, C Lynn; Smith, James F; Novak, Stephen J

    2013-09-01

    Assessing propagule pressure and geographic origins of invasive species provides insight into the invasion process. Rush skeletonweed (Chondrilla juncea; Asteraceae) is an apomictic, perennial plant that is invasive in Australia, South America (Argentina), and North America (Canada and the United States). This study comprehensively compares propagule pressure and geographic structure of genotypes to improve our understanding of a clonal invasion and enhance management strategies. • We analyzed 1056 native range plants from Eurasia and 1156 plants from three invaded continents using amplified fragment length polymorphism (AFLP) techniques. We used measures of diversity (Simpson's D) and evenness (E), analysis of molecular variance, and Mantel tests to compare invasions, and genotype similarity to determine origins of invasive genotypes. • We found 682 unique genotypes in the native range, but only 13 in the invaded regions. Each invaded region contained distinct AFLP genotypes, suggesting independent introduction events, probably with different geographic origins. Relatively low propagule pressure was associated with each introduction around the globe, but levels of among-population variation differed. We found exact AFLP genotype matches between the native and invaded ranges for five of the 13 invasive genotypes. • Invasion dynamics can vary across invaded ranges within a species. Intensive sampling for molecular analyses can provide insight for understanding intraspecific invasion dynamics, which can hold significance for the management of plant species, especially by finding origins and distributions of invasive genotypes for classical biological control efforts.

  15. over time

    Directory of Open Access Journals (Sweden)

    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.

  16. Habitat heterogeneity influences restoration efficacy: Implications of a habitat-specific management regime for an invaded marsh

    Science.gov (United States)

    Tang, Long; Gao, Yang; Wang, Cheng-Huan; Li, Bo; Chen, Jia-Kuan; Zhao, Bin

    2013-07-01

    Invasive species have to be managed to prevent adverse consequences. Spartina alterniflora has invaded many marshes where salinity and inundation are often key factors affecting vegetation. The former was surface clipped twice and native Phragmites australis was planted in invaded zones to examine the effects of habitat properties on the efficacy of invader control and native restoration. The results showed that two clipping treatments almost eliminated S. alterniflora in the zones with long inundation periods of 80 h/15 d but stimulated compensatory growth of S. alterniflora in the zones with short inundation periods. Transplanted P. australis performed better over time in zones with low salinity (removal of the above-ground parts of S. alterniflora should be used only in the middle tidal zones and that native vegetation should be planted in zones above the mean high water level while the others zones in the saltmarsh should be restored to mud flats. Usually, invasive plants can flourish in highly heterogeneous habitats, which can influence management efficacy by influencing the re-growth of treated invaders and the performance of restored native species. Therefore, habitat-specific management regimes for invasive species can be expected to be more efficient because of their dependence on specific habitats.

  17. Linking niche theory to ecological impacts of successful invaders: insights from resource fluctuation-specialist herbivore interactions.

    Science.gov (United States)

    Gidoin, Cindy; Roques, Lionel; Boivin, Thomas

    2015-03-01

    Theories of species coexistence and invasion ecology are fundamentally connected and provide a common theoretical framework for studying the mechanisms underlying successful invasions and their ecological impacts. Temporal fluctuations in resource availability and differences in life-history traits between invasive and resident species are considered as likely drivers of the dynamics of invaded communities. Current critical issues in invasion ecology thus relate to the extent to which such mechanisms influence coexistence between invasive and resident species and to the ability of resident species to persist in an invasive-dominated ecosystem. We tested how a fluctuating resource, and species trait differences may explain and help predict long-term impacts of biological invasions in forest specialist insect communities. We used a simple invasion system comprising closely related invasive and resident seed-specialized wasps (Hymenoptera: Torymidae) competing for a well-known fluctuating resource and displaying divergent diapause, reproductive and phenological traits. Based on extensive long-term field observations (1977-2010), we developed a combination of mechanistic and statistical models aiming to (i) obtain a realistic description of the population dynamics of these interacting species over time, and (ii) clarify the respective contributions of fluctuation-dependent and fluctuation-independent mechanisms to long-term impact of invasion on the population dynamics of the resident wasp species. We showed that a fluctuation-dependent mechanism was unable to promote coexistence of the resident and invasive species. Earlier phenology of the invasive species was the main driver of invasion success, enabling the invader to exploit an empty niche. Phenology also had the greatest power to explain the long-term negative impact of the invasive on the resident species, through resource pre-emption. This study provides strong support for the critical role of species

  18. An Ecosystem-Service Approach to Evaluate the Role of Non-Native Species in Urbanized Wetlands

    Directory of Open Access Journals (Sweden)

    Rita S. W. Yam

    2015-04-01

    Full Text Available Natural wetlands have been increasingly transformed into urbanized ecosystems commonly colonized by stress-tolerant non-native species. Although non-native species present numerous threats to natural ecosystems, some could provide important benefits to urbanized ecosystems. This study investigated the extent of colonization by non-native fish and bird species of three urbanized wetlands in subtropical Taiwan. Using literature data the role of each non-native species in the urbanized wetland was evaluated by their effect (benefits/damages on ecosystem services (ES based on their ecological traits. Our sites were seriously colonized by non-native fishes (39%–100%, but <3% by non-native birds. Although most non-native species could damage ES regulation (disease control and wastewater purification, some could be beneficial to the urbanized wetland ES. Our results indicated the importance of non-native fishes in supporting ES by serving as food source to fish-eating waterbirds (native, and migratory species due to their high abundance, particularly for Oreochromis spp. However, all non-native birds are regarded as “harmful” species causing important ecosystem disservices, and thus eradication of these bird-invaders from urban wetlands would be needed. This simple framework for role evaluation of non-native species represents a holistic and transferable approach to facilitate decision making on management priority of non-native species in urbanized wetlands.

  19. Stress tolerance and ecophysiological ability of an invader and a native species in a seasonally dry tropical forest.

    Science.gov (United States)

    Oliveira, Marciel Teixeira; Matzek, Virginia; Dias Medeiros, Camila; Rivas, Rebeca; Falcão, Hiram Marinho; Santos, Mauro Guida

    2014-01-01

    Ecophysiological traits of Prosopis juliflora (Sw.) DC. and a phylogenetically and ecologically similar native species, Anadenanthera colubrina (Vell.) Brenan, were studied to understand the invasive species' success in caatinga, a seasonally dry tropical forest ecosystem of the Brazilian Northeast. To determine if the invader exhibited a superior resource-capture or a resource-conservative strategy, we measured biophysical and biochemical parameters in both species during dry and wet months over the course of two years. The results show that P. juliflora benefits from a flexible strategy in which it frequently outperforms the native species in resource capture traits under favorable conditions (e.g., photosynthesis), while also showing better stress tolerance (e.g., antioxidant activity) and water-use efficiency in unfavorable conditions. In addition, across both seasons the invasive has the advantage over the native with higher chlorophyll/carotenoids and chlorophyll a/b ratios, percent N, and leaf protein. We conclude that Prosopis juliflora utilizes light, water and nutrients more efficiently than Anadenanthera colubrina, and suffers lower intensity oxidative stress in environments with reduced water availability and high light radiation.

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

    Science.gov (United States)

    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.

  1. Experimental control of Spanish broom (Spartium junceum invading natural grasslands

    Directory of Open Access Journals (Sweden)

    Cristina Sanhueza

    2012-12-01

    Full Text Available A group of legumes generically known as brooms are among the most successful shrubs invading grasslands in South America and otherregions. These species share a set of biological features that enhance their invasiveness, such as abundant and long-lasting seed banks,aggressive root systems and rapid growth, combined with their ability for re-sprouting after cutting or burning and for avoiding herbivores.They grow in dense stands that exclude native vegetation and are able to change ecological processes, increasing fire frequency and intensity,and fixing atmospheric nitrogen. The Spanish broom (Spartium junceum is a shrub native form the Mediterranean that was introduced intothe Argentine Pampas grasslands where it spreads over remnants of pristine ecosystems, threatening their biodiversity. This paper reports theresults obtained after an adaptive management strategy aimed at controlling this species in a nature reserve, and compares the efficiency ofdifferent mechanical and chemical control techniques in terms of the number of plants killed and the effects on surrounding vegetation andon the recruitment of broom seedlings. Control was implemented in two phases, the first included three treatments: i cut at the base of theplant, ii cut followed by the immediate application of Togar (Picloram 3% + Triclopyr 6%, at a 5% dilution in diesel oil on top of the cut stump, and iii foliar spraying with Togar. The follow-up treatments, implemented one year later, consisted of spraying the re-sprouts with Togar (5% in diesel oil or Glyphosate 36% (2% in water. The best option in terms of controlling Spanish broom was spraying the resprouts with Togar which gave 100% mortality of the treated plants, compared with values of 40% - 100% re-sprouting for the other optionstested. None of the methods was associated with an increase in seedling recruitment, nor with significant changes in the vegetation in the immediate vicinity of the controlled brooms.

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

    Science.gov (United States)

    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.

  3. Traits of Heracleum sosnowskyi Plants in Monostand on Invaded Area.

    Directory of Open Access Journals (Sweden)

    Igor V Dalke

    Full Text Available The ability of giant hogweeds to form monodominant communities and even pure monostands in invaded areas has been well documented. Understanding of the mechanisms leading to monostand formation can aid in determining the limitations of existing community ecology models and establishing an effective management plan for invasive species elimination. The aim of this observational study was to investigate traits of Heracleum sosnowskyi plants (demography, canopy structure, morphology and physiology of the plants in a pure stand in an invaded area useful for understanding potential monostand formation mechanisms. All measurements were performed in one typical Heracleum sosnowskyi monostand located in an abandoned agriculture field located in Syktyvkar city suburb (North-east Russia. This monostand consisted of five main plant growth stages: seed, seedling, juvenile, vegetative adult, and generative adult. Plants of all stages began to grow simultaneously shortly after the snowmelt, at the same time as spring ephemeral plant species grew. The density of generative plants did not change during the vegetation period, but the density of the other plant stages rapidly decreased after the formation of a tall (up to 2-2.5 m and dense (Leaf area index up to 6.5 canopy. The canopy captured approximately 97% of the light. H. sosnowskyi showed high (several orders of magnitude higher than average taiga zone grasses photosynthetic water use efficiency (6-7 μM CO2/μM H2O. Formation of H. sosnowskyi monostands occurs primarily in disturbed areas with relatively rich and well-moistened soils. Early commencement of growth, rapid formation of a dense canopy, high efficiency of light and water use during photosynthesis, ability of young plants to survive in low light conditions, rapid recovery of above-ground plant parts after damage, and the high density of the soil seed bank are the most important traits of H. sosnowskyi plants for monostand formation in invaded

  4. Invasive species triggers a massive loss of ecosystem services through a trophic cascade.

    Science.gov (United States)

    Walsh, Jake R; Carpenter, Stephen R; Vander Zanden, M Jake

    2016-04-12

    Despite growing recognition of the importance of ecosystem services and the economic and ecological harm caused by invasive species, linkages between invasions, changes in ecosystem functioning, and in turn, provisioning of ecosystem services remain poorly documented and poorly understood. We evaluate the economic impacts of an invasion that cascaded through a food web to cause substantial declines in water clarity, a valued ecosystem service. The predatory zooplankton, the spiny water flea (Bythotrephes longimanus), invaded the Laurentian Great Lakes in the 1980s and has subsequently undergone secondary spread to inland lakes, including Lake Mendota (Wisconsin), in 2009. In Lake Mendota, Bythotrephes has reached unparalleled densities compared with in other lakes, decreasing biomass of the grazer Daphnia pulicaria and causing a decline in water clarity of nearly 1 m. Time series modeling revealed that the loss in water clarity, valued at US$140 million (US$640 per household), could be reversed by a 71% reduction in phosphorus loading. A phosphorus reduction of this magnitude is estimated to cost between US$86.5 million and US$163 million (US$430-US$810 per household). Estimates of the economic effects of Great Lakes invasive species may increase considerably if cases of secondary invasions into inland lakes, such as Lake Mendota, are included. Furthermore, such extreme cases of economic damages call for increased investment in the prevention and control of invasive species to better maximize the economic benefits of such programs. Our results highlight the need to more fully incorporate ecosystem services into our analysis of invasive species impacts, management, and public policy.

  5. A modelling framework for improving plant establishment during ecological restoration

    Science.gov (United States)

    Plants seeded during ecological restoration projects often perish en masse, and researchers are currently searching for traits promoting increased survival. In this study of a big sagebrush (Artemisia tridentata Nutt.) ecosystem, we found survivorship rankings of seeded grass species varied across 3...

  6. Comparing methods for measuring the rate of spread of invading populations

    Science.gov (United States)

    Marius Gilbert; Andrew. Liebhold

    2010-01-01

    Measuring rates of spread during biological invasions is important for predicting where and when invading organisms will spread in the future as well as for quantifying the influence of environmental conditions on invasion speed. While several methods have been proposed in the literature to measure spread rates, a comprehensive comparison of their accuracy when applied...

  7. Listeria monocytogenes efficiently invades caco-2 cells after low-temperature storage in broth and on deli meat

    DEFF Research Database (Denmark)

    Larsen, Marianne Halberg; Koch, Anette Granly; Ingmer, Hanne

    2010-01-01

    The objective of this study was to investigate how various growth conditions influence the virulence of Listeria monocytogenes monitored by its ability to invade the epithelial cell lines Caco-2 and INT-407. The growth conditions examined were modified atmosphere-packaged deli meat and brain heart...... infusion broth (BHI) with and without salt. Five strains of L. monocytogenes were selected to investigate their invasiveness and all strains invaded Caco-2 cells at higher levels than INT-407 cells. Further, the clinical strains (3443 and 3734) were more invasive (p ... to invade Caco-2 cells was compared after growth on a fermented sausage and on cured cooked ham to that of bacteria grown in BHI broth supplemented with salt. Samples were stored under chilling conditions for up to 4 weeks. The results showed no difference (p > 0.05) in invasiveness after 7 days at 10...

  8. The impact of failure: unsuccessful bacterial invasions steer the soil microbial community away from the invader's niche.

    Science.gov (United States)

    Mallon, C A; Le Roux, X; van Doorn, G S; Dini-Andreote, F; Poly, F; Salles, J F

    2018-03-01

    Although many environments like soils are constantly subjected to invasion by alien microbes, invaders usually fail to succeed, succumbing to the robust diversity often found in nature. So far, only successful invasions have been explored, and it remains unknown to what extent an unsuccessful invasion can impact resident communities. Here we hypothesized that unsuccessful invasions can cause impacts to soil functioning by decreasing the diversity and niche breadth of resident bacterial communities, which could cause shifts to community composition and niche structure-an effect that is likely exacerbated when diversity is compromised. To examine this question, diversity gradients of soil microbial communities were subjected to invasion by the frequent, yet oft-unsuccessful soil invader, Escherichia coli, and evaluated for changes to diversity, bacterial community composition, niche breadth, and niche structure. Contrary to expectations, diversity and niche breadth increased across treatments upon invasion. Community composition and niche structure were also altered, with shifts of niche structure revealing an escape by the resident community away from the invader's resources. Importantly, the extent of the escape varied in response to the community's diversity, where less diverse communities experienced larger shifts. Thus, although transient and unsuccessful, the invader competed for resources with resident species and caused tangible impacts that modified both the diversity and functioning of resident communities, which can likely generate a legacy effect that influences future invasion attempts.

  9. 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.

  10. 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.

  11. Impacts of exotic mangrove forests and mangrove deforestation on carbon remineralization and ecosystem functioning in marine sediments

    Science.gov (United States)

    Sweetman, A.K.; Middelburg, J.J.; Berle, A.M.; Bernardino, A.F.; Schander, C.; Demopoulos, A.W.J.; Smith, C.R.

    2010-01-01

    To evaluate how mangrove invasion and removal can modify benthic carbon cycling processes and ecosystem functioning, we used stable-isotopically labelled algae as a deliberate tracer to quantify benthic respiration and C-flow through macrofauna and bacteria in sediments collected from (1) an invasive mangrove forest, (2) deforested mangrove sites 2 and 6 years after removal of above-sediment mangrove biomass, and (3) two mangrove-free, control sites in the Hawaiian coastal zone. Sediment oxygen consumption (SOC) rates were significantly greater in the mangrove and mangrove removal site experiments than in controls and were significantly correlated with total benthic (macrofauna and bacteria) biomass and sedimentary mangrove biomass (SMB). Bacteria dominated short-term C-processing of added microalgal-C and benthic biomass in sediments from the invasive mangrove forest habitat. In contrast, macrofauna were the most important agents in the short-term processing of microalgal-C in sediments from the mangrove removal and control sites. Mean faunal abundance and short term C-uptake rates in sediments from both removal sites were significantly higher than in control cores, which collectively suggest that community structure and short-term C-cycling dynamics in habitats where mangroves have been cleared can remain fundamentally different from un-invaded mudflat sediments for at least 6-yrs following above-sediment mangrove removal. In summary, invasion by mangroves can lead to large shifts in benthic ecosystem function, with sediment metabolism, benthic community structure and short-term C-remineralization dynamics being affected for years following invader removal. ?? 2010 Author(s).

  12. Ecosystem evolution of Lake Gusinoe (Transbaikal region, Russia)

    Energy Technology Data Exchange (ETDEWEB)

    Pisarsky, B.L.; Hardina, A.M.; Naganawa, H. [Russian Academy of Science, Irkutsk (Russian Federation). Siberian Division

    2005-12-01

    Lake Gusinoe is situated on a basin originating from Paleozoic and Mesozoic deposits. The recorded history of the lake's ecosystem evolution is no more than 300 years. The present lake drainage basin was formed mainly in the Cenozoic era, but during the past century, major anthropogenic impacts on the lake have occurred. The human-influenced evolution of the ecosystem began in the 1940s with the development of opencut coal mining nearby the lake. Population increase and the building of the Gusinoozersk State Regional Power Plant, the TransMongolian Railroad and an associated station, and military installations were the major sources of anthropogenic impacts. Since the early 1950s about five species of fish have been introduced into Lake Gusinoe or have invaded the lake, and at least six of the native species have disappeared or are in danger of extinction. From our recent investigations, the present environment of the Lake Gusinoe Basin (Gusinoozersk Basin) is divided into four zones hydro-geochemically: (1) ultrafreshwater, (2) freshwater, (3) mineralized water, and (4) hyposaline and saltwater. Some additional data on changes of the chemical components of the drainage basin waters, as well as on the transition of zooplankton and zoobenthic fauna, are presented in consideration of the risk of industrial development, and the perspectives are discussed.

  13. Freshwater ecosystems and aquatic insects: a paradox in biological invasions.

    Science.gov (United States)

    Fenoglio, Stefano; Bonada, Núria; Guareschi, Simone; López-Rodríguez, Manuel J; Millán, Andrés; Tierno de Figueroa, J Manuel

    2016-04-01

    Biological invasions have increased significantly in response to global change and constitute one of the major causes of biodiversity loss. Insects make up a large fraction of invasive species, in general, and freshwaters are among the most invaded ecosystems on our planet. However, even though aquatic insects dominate most inland waters, have unparalleled taxonomic diversity and occupy nearly all trophic niches, there are almost no invasive insects in freshwaters. We present some hypotheses regarding why aquatic insects are not common among aquatic invasive organisms, suggesting that it may be the result of a suite of biological, ecological and anthropogenic factors. Such specific knowledge introduces a paradox in the current scientific discussion on invasive species; therefore, a more in-depth understanding could be an invaluable aid to disentangling how and why biological invasions occur. © 2016 The Author(s).

  14. Endangered species management and ecosystem restoration: Finding the common ground

    Science.gov (United States)

    Casazza, Michael L.; Overton, Cory T.; Bui, Thuy-Vy D.; Hull, Joshua M.; Albertson, Joy D.; Bloom, Valary K.; Bobzien, Steven; McBroom, Jennifer; Latta, Marilyn; Olofson, Peggy; Rohmer, Tobias M.; Schwarzbach, Steven E.; Strong, Donald R.; Grijalva, Erik; Wood, Julian K.; Skalos, Shannon; Takekawa, John Y.

    2016-01-01

    Management actions to protect endangered species and conserve ecosystem function may not always be in precise alignment. Efforts to recover the California Ridgway’s Rail (Rallus obsoletus obsoletus; hereafter, California rail), a federally and state-listed species, and restoration of tidal marsh ecosystems in the San Francisco Bay estuary provide a prime example of habitat restoration that has conflicted with species conservation. On the brink of extinction from habitat loss and degradation, and non-native predators in the 1990s, California rail populations responded positively to introduction of a non-native plant, Atlantic cordgrass (Spartina alterniflora). California rail populations were in substantial decline when the non-native Spartina was initially introduced as part of efforts to recover tidal marshes. Subsequent hybridization with the native Pacific cordgrass (Spartina foliosa) boosted California rail populations by providing greater cover and increased habitat area. The hybrid cordgrass (S. alterniflora × S. foliosa) readily invaded tidal mudflats and channels, and both crowded out native tidal marsh plants and increased sediment accretion in the marsh plain. This resulted in modification of tidal marsh geomorphology, hydrology, productivity, and species composition. Our results show that denser California rail populations occur in invasive Spartina than in native Spartina in San Francisco Bay. Herbicide treatment between 2005 and 2012 removed invasive Spartina from open intertidal mud and preserved foraging habitat for shorebirds. However, removal of invasive Spartina caused substantial decreases in California rail populations. Unknown facets of California rail ecology, undesirable interim stages of tidal marsh restoration, and competing management objectives among stakeholders resulted in management planning for endangered species or ecosystem restoration that favored one goal over the other. We have examined this perceived conflict and propose

  15. Endangered species management and ecosystem restoration: finding the common ground

    Directory of Open Access Journals (Sweden)

    Michael L. Casazza

    2016-03-01

    Full Text Available Management actions to protect endangered species and conserve ecosystem function may not always be in precise alignment. Efforts to recover the California Ridgway's Rail (Rallus obsoletus obsoletus; hereafter, California rail, a federally and state-listed species, and restoration of tidal marsh ecosystems in the San Francisco Bay estuary provide a prime example of habitat restoration that has conflicted with species conservation. On the brink of extinction from habitat loss and degradation, and non-native predators in the 1990s, California rail populations responded positively to introduction of a non-native plant, Atlantic cordgrass (Spartina alterniflora. California rail populations were in substantial decline when the non-native Spartina was initially introduced as part of efforts to recover tidal marshes. Subsequent hybridization with the native Pacific cordgrass (Spartina foliosa boosted California rail populations by providing greater cover and increased habitat area. The hybrid cordgrass (S. alterniflora à - S. foliosa readily invaded tidal mudflats and channels, and both crowded out native tidal marsh plants and increased sediment accretion in the marsh plain. This resulted in modification of tidal marsh geomorphology, hydrology, productivity, and species composition. Our results show that denser California rail populations occur in invasive Spartina than in native Spartina in San Francisco Bay. Herbicide treatment between 2005 and 2012 removed invasive Spartina from open intertidal mud and preserved foraging habitat for shorebirds. However, removal of invasive Spartina caused substantial decreases in California rail populations. Unknown facets of California rail ecology, undesirable interim stages of tidal marsh restoration, and competing management objectives among stakeholders resulted in management planning for endangered species or ecosystem restoration that favored one goal over the other. We have examined this perceived conflict

  16. Listeria monocytogenes efficiently invades Caco-2 cells after low-temperature storage in broth and on deli meat.

    Science.gov (United States)

    Larsen, Marianne Halberg; Koch, Anette Granly; Ingmer, Hanne

    2010-09-01

    The objective of this study was to investigate how various growth conditions influence the virulence of Listeria monocytogenes monitored by its ability to invade the epithelial cell lines Caco-2 and INT-407. The growth conditions examined were modified atmosphere-packaged deli meat and brain heart infusion broth (BHI) with and without salt. Five strains of L. monocytogenes were selected to investigate their invasiveness and all strains invaded Caco-2 cells at higher levels than INT-407 cells. Further, the clinical strains (3443 and 3734) were more invasive (p 0.05) in invasiveness after 7 days at 10 degrees C in BHI broth or on sausage, whereas a slight increase (p < 0.05) was observed after incubation on ham for 2 and 4 weeks compared to that in BHI broth. Most importantly, our results show that L. monocytogenes efficiently invade Caco-2 cells even after 4 weeks of storage at chilled temperature. This is highly relevant for safety assessment of this organism in food as these conditions reflect storage of ready-to-eat food products in domestic refrigerators.

  17. The Integrated Rangeland Fire Management Strategy Actionable Science Plan: U.S. Department of the Interior, Washington D.C.

    Science.gov (United States)

    Integrated Rangeland Fire Management Strategy Actionable Science Plan Team

    2016-01-01

    The Integrated Rangeland Fire Management Strategy (hereafter Strategy, DOI 2015) outlined the need for coordinated, science-based adaptive management to achieve long-term protection, conservation, and restoration of the sagebrush (Artemisia spp.) ecosystem. A key component of this management approach is the identification of knowledge gaps that limit...

  18. Hemigrapsus sanguineus in Long Island salt marshes: experimental evaluation of the interactions between an invasive crab and resident ecosystem engineers

    Directory of Open Access Journals (Sweden)

    Bradley J. Peterson

    2014-07-01

    Full Text Available The invasive Asian shore crab, Hemigrapsus sanguineus, has recently been observed occupying salt marshes, a novel environment for this crab species. As it invades this new habitat, it is likely to interact with a number of important salt marsh species. To understand the potential effects of H. sanguineus on this ecosystem, interactions between this invasive crab and important salt marsh ecosystem engineers were examined. Laboratory experiments demonstrated competition for burrows between H. sanguineus and the native fiddler crab, Uca pugilator. Results indicate that H. sanguineus is able to displace an established fiddler crab from its burrow. Feeding experiments revealed that the presence of H. sanguineus has a significantly negative impact on the number as well as the biomass of ribbed mussels (Geukensia demissa consumed by the green crab, Carcinus maenas, although this only occurred at high predator densities. In addition, when both crabs foraged together, there was a significant shift in the size of mussels consumed. These interactions suggests that H. sanguineus may have long-term impacts and wide-ranging negative effects on the saltmarsh ecosystem.

  19. Hemigrapsus sanguineus in Long Island salt marshes: experimental evaluation of the interactions between an invasive crab and resident ecosystem engineers.

    Science.gov (United States)

    Peterson, Bradley J; Fournier, Alexa M; Furman, Bradley T; Carroll, John M

    2014-01-01

    The invasive Asian shore crab, Hemigrapsus sanguineus, has recently been observed occupying salt marshes, a novel environment for this crab species. As it invades this new habitat, it is likely to interact with a number of important salt marsh species. To understand the potential effects of H. sanguineus on this ecosystem, interactions between this invasive crab and important salt marsh ecosystem engineers were examined. Laboratory experiments demonstrated competition for burrows between H. sanguineus and the native fiddler crab, Uca pugilator. Results indicate that H. sanguineus is able to displace an established fiddler crab from its burrow. Feeding experiments revealed that the presence of H. sanguineus has a significantly negative impact on the number as well as the biomass of ribbed mussels (Geukensia demissa) consumed by the green crab, Carcinus maenas, although this only occurred at high predator densities. In addition, when both crabs foraged together, there was a significant shift in the size of mussels consumed. These interactions suggests that H. sanguineus may have long-term impacts and wide-ranging negative effects on the saltmarsh ecosystem.

  20. Invasion and predation in aquatic ecosystems

    Directory of Open Access Journals (Sweden)

    Judith S. WEIS

    2011-10-01

    Full Text Available This article reviews biological invasions in which predation (or its absence plays a major role in the success of the invader. Examples are described in which the invader out-competes native species for the same food, and cases in which the invader consumes valued native species. In many instances, better predator avoidance by the invasive species or the absence of predators in the new habitat contributes to the success of the invaders; in other cases native or introduced predators appear to be able to keep the invasive species in check. A relatively new management approach in the US is the idea of adding another trophic level – to have humans act as the predators and consume the invasive species. This approach is being utilized in Florida and throughout the Caribbean against the lionfish, but could be extended to other fishes, as well as to various invasive crustaceans and mollusks. This idea is controversial, and current regulations prohibiting the possession of individuals of the invasive species (e.g., mitten crabs or snakefish would preclude the development of a fishery for them [Current Zoology 57 (5: 613–624, 2011].

  1. Carbon fluxes in ecosystems of Yellowstone National Park predicted from remote sensing data and simulation modeling.

    Science.gov (United States)

    Potter, Christopher; Klooster, Steven; Crabtree, Robert; Huang, Shengli; Gross, Peggy; Genovese, Vanessa

    2011-08-11

    A simulation model based on remote sensing data for spatial vegetation properties has been used to estimate ecosystem carbon fluxes across Yellowstone National Park (YNP). The CASA (Carnegie Ames Stanford Approach) model was applied at a regional scale to estimate seasonal and annual carbon fluxes as net primary production (NPP) and soil respiration components. Predicted net ecosystem production (NEP) flux of CO2 is estimated from the model for carbon sinks and sources over multi-year periods that varied in climate and (wildfire) disturbance histories. Monthly Enhanced Vegetation Index (EVI) image coverages from the NASA Moderate Resolution Imaging Spectroradiometer (MODIS) instrument (from 2000 to 2006) were direct inputs to the model. New map products have been added to CASA from airborne remote sensing of coarse woody debris (CWD) in areas burned by wildfires over the past two decades. Model results indicated that relatively cooler and wetter summer growing seasons were the most favorable for annual plant production and net ecosystem carbon gains in representative landscapes of YNP. When summed across vegetation class areas, the predominance of evergreen forest and shrubland (sagebrush) cover was evident, with these two classes together accounting for 88% of the total annual NPP flux of 2.5 Tg C yr-1 (1 Tg = 1012 g) for the entire Yellowstone study area from 2000-2006. Most vegetation classes were estimated as net ecosystem sinks of atmospheric CO2 on annual basis, making the entire study area a moderate net sink of about +0.13 Tg C yr-1. This average sink value for forested lands nonetheless masks the contribution of areas burned during the 1988 wildfires, which were estimated as net sources of CO2 to the atmosphere, totaling to a NEP flux of -0.04 Tg C yr-1 for the entire burned area. Several areas burned in the 1988 wildfires were estimated to be among the lowest in overall yearly NPP, namely the Hellroaring Fire, Mink Fire, and Falls Fire areas. Rates of

  2. 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.

  3. 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.

  4. "Pleistocene Park" - A Glacial Ecosystem in a Warming World

    Science.gov (United States)

    Zimov, N.; Zimov, S. A.

    2011-12-01

    Most people if asked what association they have to the phrase - ice age, will answer - "Mammoth". But mammoths are not only big wooly elephants which went extinct in the beginning of Holocene. They were also part of a great ecosystem, the Northern Steppe or Mammoth Ecosystem, which was the world's largest ecosystem for hundreds thousand of years. This ecosystem, with extremely high rates of biocycling, could maintain animal densities which can be hardly found anywhere in the modern world. Northern steppe played an important role in shaping the glacial climate of the planet. High albedo grasslands reflected a much bigger portion of sun heat back to the atmosphere. Cold soils and permafrost served as sinks of carbon, helping to keep greenhouse gas concentration in the atmosphere at low levels. In the beginning of Holocene, simultaneously with wave of human expansion, an extinction wave took place. Tens of megafauna species became extinct at that time worldwide, while ones that resisted the extinction substantially dropped in numbers. The Northern Steppe ecosystem became imbalanced. Without large numbers of herbivores grazing and trampling the pasture, trees, shrubs and moss invaded grasslands. Within just a few hundreds years the mammoth ecosystem was gone, replaced by much lower productivity ecosystems. Already 14 thousand year ago, by simply increasing hunting pressure, humans managed to dramatically change Earth's appearance. We propose that by artificially maintaining a high animal density and diversity on a limited territory for extended period of time, it will be possible to reverse the shift, reestablishing the productive Northern Steppe ecosystem. Moss, shrubs and tree sprouts are not able to resist grazing pressure so they will be quickly replaced by grasses and herbs. Animals digesting all aboveground biomass would accelerate nutrition cycling and consequently increase bioproductivity. Higher bioproductivity would increase evapotranspiration, keeping soils

  5. Placenta Percreta Invading Broad Ligament and Parametrium in a Woman with Two Previous Cesarean Sections: A Case Report

    Directory of Open Access Journals (Sweden)

    Mansoureh Vahdat

    2012-01-01

    Full Text Available Introduction. The incidence of placenta accreta has dramatically increased due to increasing caesarean section rate all over the world. Placenta percreta is the most severe form of placenta accretes. It frequently results in maternal morbidity and mortality mainly caused by massive obstetric hemorrhage or emergency hysterectomy. Percreta invading into the broad ligament has rarely been previously reported. Case presenting. We presented a case of placenta percreta invading left broad ligament and parametrium in a woman with two previous cesarean sections, which led to massive intraoperative hemorrhage during hysterectomy and transient ischemic encephalopathy. Conclusion. In cases of parametrial involvement, it would be more difficult to decide whether to remove placenta or leave it in site. In surgical removal neither local excision of placental bed and uterine repair nor traditional hysterectomy is adequate if parametrium invaded by placenta. We suggest delayed elective hysterectomy in such cases. So, pregnancy-induced pelvic congestion would be decreased, we can gather an expert team of gynecologists, urologists, and vascular surgeons, we could get plenty of blood products, and we may have the chance to administer methotrexate.

  6. Soil recovery after removal of the N2-fixing invasive Acacia longifolia: consequences for ecosystem restoration

    DEFF Research Database (Denmark)

    Marchante, Elizabete; Kjøller, Annelise Helene; Struwe, Sten

    2009-01-01

    Invasion by Acacia longifolia alters soil characteristics and processes. The present study was conducted to determine if the changes in soil C and N pools and processes induced by A. longifolia persist after its removal, at the São Jacinto Dunes Nature Reserve (Portugal). Some areas had been...... invaded for a long time (>20 years) and others more recently (Soil samples...... decrease (>54% and >95%, respectively) after removal of both A. longifolia and litter. Our results suggest that after removal of an N2-fixing invasive tree that changes ecosystem-level processes, it takes several years before soil nutrients and processes return to pre-invasion levels, but this legacy...

  7. Prescribed fire opportunities in grasslands invaded by Douglas-fir: state-of-the-art guidelines

    Science.gov (United States)

    George E. Gruell; James K. Brown; Charles L. Bushey

    1986-01-01

    Provides information on use of prescribed fire to enhance productivity of bunchgrass ranges that have been invaded by Douglas-fir. Six vegetative "situations" representative of treatment opportunities most commonly encountered in Montana are discussed. Included are fire prescription considerations and identification of the resource objective, fire objective,...

  8. Climate-based models for pulsed resources improve predictability of consumer population dynamics: outbreaks of house mice in forest ecosystems.

    Directory of Open Access Journals (Sweden)

    E Penelope Holland

    Full Text Available Accurate predictions of the timing and magnitude of consumer responses to episodic seeding events (masts are important for understanding ecosystem dynamics and for managing outbreaks of invasive species generated by masts. While models relating consumer populations to resource fluctuations have been developed successfully for a range of natural and modified ecosystems, a critical gap that needs addressing is better prediction of resource pulses. A recent model used change in summer temperature from one year to the next (ΔT for predicting masts for forest and grassland plants in New Zealand. We extend this climate-based method in the framework of a model for consumer-resource dynamics to predict invasive house mouse (Mus musculus outbreaks in forest ecosystems. Compared with previous mast models based on absolute temperature, the ΔT method for predicting masts resulted in an improved model for mouse population dynamics. There was also a threshold effect of ΔT on the likelihood of an outbreak occurring. The improved climate-based method for predicting resource pulses and consumer responses provides a straightforward rule of thumb for determining, with one year's advance warning, whether management intervention might be required in invaded ecosystems. The approach could be applied to consumer-resource systems worldwide where climatic variables are used to model the size and duration of resource pulses, and may have particular relevance for ecosystems where global change scenarios predict increased variability in climatic events.

  9. Responses to invasion and invader removal differ between native and exotic plant groups in a coastal dune.

    Science.gov (United States)

    Magnoli, Susan M; Kleinhesselink, Andrew R; Cushman, J Hall

    2013-12-01

    The spread of exotic, invasive species is a global phenomenon that is recognized as a major source of environmental change. Although many studies have addressed the effects of exotic plants on the communities they invade, few have quantified the effects of invader removal on plant communities, or considered the degree to which different plant groups vary in response to invasion and invader removal. We evaluated the effects of an exotic succulent, iceplant (Carpobrotus edulis), on a coastal dune plant community in northern California, as well as the community responses to its removal. To assess possible mechanisms by which iceplant affects other plants, we also evaluated its above- and belowground influences on the germination and growth of a dominant exotic annual grass, Bromus diandrus. We found that iceplant invasion was associated with reduced native plant cover as well as increased cover and density of some exotic plants-especially exotic annual grasses. However, iceplant removal did not necessarily lead to a reversal of these effects: removal increased the cover and density of both native and exotic species. We also found that B. diandrus grown in iceplant patches, or in soil where iceplant had been removed, had poorer germination and growth than B. diandrus grown in soil not influenced by iceplant. This suggests that the influence of iceplant on this dune plant community occurs, at least in part, due to belowground effects, and that these effects remain after iceplant has been removed. Our study demonstrates the importance of considering how exotic invasive plants affect not only native species, but also co-occurring exotic taxa. It also shows that combining observational studies with removal experiments can lead to important insights into the influence of invaders and the mechanisms of their effects.

  10. Strategic management of five deciduous forest invaders using Microstegium vimineum as a model species

    Science.gov (United States)

    Cynthia D. Huebner

    2007-01-01

    This paper links key plant invasive traits with key landscape traits to define strategic management for five common forest invaders, using empirical data of Microstegium vimineum dispersal into forests as a preliminary model. Microstegium vimineum exhibits an Allee effect that may allow management to focus on treating its source...

  11. Millennium Ecosystem Assessment: MA Ecosystems

    Data.gov (United States)

    National Aeronautics and Space Administration — The Millennium Ecosystem Assessment: MA Ecosystems provides data and information on the extent and classification of ecosystems circa 2000, including coastal,...

  12. A taste for novelty in invading house sparrows, Passer domesticus

    OpenAIRE

    Lynn B. Martin; Lisa Fitzgerald

    2005-01-01

    One of the central questions in invasion biology involves why some introductions succeed and others fail. Although several correlates of invasion success have been identified, patterns alone cannot identify the mechanisms underlying the invasion process. Here, we test the hypothesis that one predictor of invasion success, behavioral flexibility, is different between invading and established populations of the same species of bird. We predicted that neophobia (fear of novelty), a surrogate of ...

  13. 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...

  14. 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...

  15. Linking removal targets to the ecological effects of invaders: a predictive model and field test.

    Science.gov (United States)

    Green, Stephanie J; Dulvy, Nicholas K; Brooks, Annabelle M L; Akins, John L; Cooper, Andrew B; Miller, Skylar; Côté, Isabelle M

    , means that we could not identify a single rule of thumb for guiding control efforts. However, our model provides a method for setting reef-specific targets for population control using local monitoring data. Our work is the first to demonstrate that for ongoing invasions, suppressing invaders below densities that cause environmental harm can have a similar effect, in terms of protecting the native ecosystem on a local scale, to achieving complete eradication.

  16. Spreaders, igniters, and burning shrubs: plant flammability explains novel fire dynamics in grass-invaded deserts.

    Science.gov (United States)

    Fuentes-Ramirez, Andres; Veldman, Joseph W; Holzapfel, Claus; Moloney, Kirk A

    2016-10-01

    Novel fire regimes are an important cause and consequence of global environmental change that involve interactions among biotic, climatic, and human components of ecosystems. Plant flammability is key to these interactions, yet few studies directly measure flammability or consider how multiple species with different flammabilities interact to produce novel fire regimes. Deserts of the southwestern United States are an ideal system for exploring how novel fire regimes can emerge when fire-promoting species invade ecosystems comprised of species that did not evolve with fire. In these deserts, exotic annual grasses provide fuel continuity across landscapes that did not historically burn. These fires often ignite a keystone desert shrub, the fire-intolerant creosote bush, Larrea tridentata (DC.) Coville. Ignition of Larrea is likely catalyzed by fuels produced by native plants that grow beneath the shrubs. We hypothesize that invasive and native species exhibit distinct flammability characteristics that in combination determine spatial patterns of fire spread and intensity. We measured flammability metrics of Larrea, two invasive grasses, Schismus arabicus and Bromus madritensis, and two native plants, the sub-shrub Ambrosia dumosa and the annual herb Amsinckia menziesii. Results of laboratory experiments show that the grasses carry fire quickly (1.32 cm/s), but burn for short duration (0.5 min) at low temperatures. In contrast, native plants spread fire slowly (0.12 cm/s), but burn up to eight times longer (4 min) and produced hotter fires. Additional experiments on the ignition requirements of Larrea suggest that native plants burn with sufficient temperature and duration to ignite dead Larrea branches (time to ignition, 2 min; temperature at ignition 692°C). Once burning, these dead branches ignite living branches in the upper portions of the shrub. Our study provides support for a conceptual model in which exotic grasses are "spreaders" of fire and native

  17. Candida albicans: The Ability to Invade Epithelial Cells and Survive under Oxidative Stress Is Unlinked to Hyphal Length

    Directory of Open Access Journals (Sweden)

    Paloma K. Maza

    2017-07-01

    Full Text Available In its hyphal form, Candida albicans invades epithelial and endothelial cells by two distinct mechanisms: active penetration and induced endocytosis. The latter is dependent on a reorganization of the host cytoskeleton (actin/cortactin recruitment, whilst active penetration does not rely on the host's cellular machinery. The first obstacle for the fungus to reach deep tissues is the epithelial barrier and this interaction is crucial for commensal growth, fungal pathogenicity and host defense. This study aimed to characterize in vitro epithelial HeLa cell invasion by four different isolates of C. albicans with distinct clinical backgrounds, including a C. albicans SC5314 reference strain. All isolates invaded HeLa cells, recruited actin and cortactin, and induced the phosphorylation of both Src-family kinases (SFK and cortactin. Curiously, L3881 isolated from blood culture of a patient exhibited the highest resistance to oxidative stress, although this isolate showed reduced hyphal length and displayed the lowest cell damage and invasion rates. Collectively, these data suggest that the ability of C. albicans to invade HeLa cells, and to reach and adapt to the host's blood, including resistance to oxidative stress, may be independent of hyphal length.

  18. Using a prescribed fire to test custom and standard fuel models for fire behaviour prediction in a non-native, grass-invaded tropical dry shrubland

    Science.gov (United States)

    Andrew D. Pierce; Sierra McDaniel; Mark Wasser; Alison Ainsworth; Creighton M. Litton; Christian P. Giardina; Susan Cordell; Ralf Ohlemuller

    2014-01-01

    Questions: Do fuel models developed for North American fuel types accurately represent fuel beds found in grass-invaded tropical shrublands? Do standard or custom fuel models for firebehavior models with in situ or RAWS measured fuel moistures affect the accuracy of predicted fire behavior in grass-invaded tropical shrublands? Location: Hawai’i Volcanoes National...

  19. Invader Relative Impact Potential: a new metric to understand and predict the ecological impacts of existing, emerging and future invasive alien species

    OpenAIRE

    Dick, JTA; Laverty, C; Lennon, JJ; Barrios-O'Neill, D; Mensink, PJ; Britton, JR; Medoc, V; Boets, P; Alexander, ME; Taylor, NG; Dunn, AM; Hatcher, MJ; Rosewarne, PJ; Crookes, S; MacIsaac, HJ

    2017-01-01

    1. Predictions of the identities and ecological impacts of invasive alien species are critical for risk assessment, but presently we lack universal and standardized metrics that reliably predict the likelihood and degree of impact of such invaders (i.e. measurable changes in populations of affected species). This need is especially pressing for emerging and potential future invaders that have no invasion history. Such a metric would also ideally apply across diverse taxonomic and trophic gro...

  20. Ecosystem-based management and the wealth of ecosystems

    OpenAIRE

    Yun, Seong Do; Hutniczak, Barbara; Abbott, Joshua K.; Fenichel, Eli P.

    2017-01-01

    Ecosystems store vast quantities of wealth, but difficulties measuring wealth held in ecosystems prevent its inclusion in accounting systems. Ecosystem-based management endeavors to manage ecosystems holistically. However, ecosystem-based management lacks headline indicators to evaluate performance. We unify the inclusive wealth and ecosystem-based management paradigms, allowing apples-to-apples comparisons between the wealth of the ecosystem and other forms of wealth, while providing a headl...

  1. Area 51: How do Acanthamoeba invade the central nervous system?

    Science.gov (United States)

    Siddiqui, Ruqaiyyah; Emes, Richard; Elsheikha, Hany; Khan, Naveed Ahmed

    2011-05-01

    Acanthamoeba granulomatous encephalitis generally develops as a result of haematogenous spread, but it is unclear how circulating amoebae enter the central nervous system (CNS) and cause inflammation. At present, the mechanisms which Acanthamoeba use to invade this incredibly well-protected area of the CNS and produce infection are not well understood. In this paper, we propose two key virulence factors: mannose-binding protein and extracellular serine proteases as key players in Acanthamoeba traversal of the blood-brain barrier leading to neuronal injury. Both molecules should provide excellent opportunities as potential targets in the rational development of therapeutic interventions against Acanthamoeba encephalitis. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Impact of invading alien plants on surface water resources in South Africa: a preliminary assessment

    CSIR Research Space (South Africa)

    Le Maitre, David C

    2000-07-01

    Full Text Available areas (the equivalent area with a canopy cover of 100%). Each of the invading species was classified as a tall shrub, medium tree or tall tree - based on growth form and likely water use - and its biomass was estimated from a function based on vegetation...

  3. Solidago canadensis invasion affects soil N-fixing bacterial communities in heterogeneous landscapes in urban ecosystems in East China.

    Science.gov (United States)

    Wang, Congyan; Jiang, Kun; Zhou, Jiawei; Wu, Bingde

    2018-03-12

    Soil nitrogen-fixing bacterial communities (SNB) can increase the level of available soil N via biological N-fixation to facilitate successful invasion of several invasive plant species (IPS). Meanwhile, landscape heterogeneity can greatly enhance regional invasibility and increase the chances of successful invasion of IPS. Thus, it is important to understand the soil micro-ecological mechanisms driving the successful invasion of IPS in heterogeneous landscapes. This study performed cross-site comparisons, via metagenomics, to comprehensively analyze the effects of Solidago canadensis invasion on SNB in heterogeneous landscapes in urban ecosystems. Rhizospheric soil samples of S. canadensis were obtained from nine urban ecosystems [Three replicate quadrats (including uninvaded sites and invaded sites) for each type of urban ecosystem]. S. canadensis invasion did not significantly affect soil physicochemical properties, the taxonomic diversity of plant communities, or the diversity and richness of SNB. However, some SNB taxa (i.e., f_Micromonosporaceae, f_Oscillatoriaceae, and f_Bacillaceae) changed significantly with S. canadensis invasion. Thus, S. canadensis invasion may alter the community structure, rather than the diversity and richness of SNB, to facilitate its invasion process. Of the nine urban ecosystems, the diversity and richness of SNB was highest in farmland wasteland. Accordingly, the community invasibility of farmland wasteland may be higher than that of the other types of urban ecosystem. In brief, landscape heterogeneity, rather than S. canadensis invasion, was the strongest controlling factor for the diversity and richness of SNB. One possible reason may be the differences in soil electrical conductivity and the taxonomic diversity of plant communities in the nine urban ecosystems, which can cause notable shifts in the diversity and richness of SNB. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Interactions among invasive plants: Lessons from Hawai‘i

    Science.gov (United States)

    D'Antonio, Carla M.; Ostertag, Rebecca; Cordell, Susan; Yelenik, Stephanie G.

    2017-01-01

    Most ecosystems have multiple-plant invaders rather than single-plant invaders, yet ecological studies and management actions focus largely on single invader species. There is a need for general principles regarding invader interactions across varying environmental conditions, so that secondary invasions can be anticipated and managers can allocate resources toward pretreatment or postremoval actions. By reviewing removal experiments conducted in three Hawaiian ecosystems (a dry tropical forest, a seasonally dry mesic forest, and a lowland wet forest), we evaluate the roles environmental harshness, priority effects, productivity potential, and species interactions have in influencing secondary invasions, defined here as invasions that are influenced either positively (facilitation) or negatively (inhibition/priority effects) by existing invaders. We generate a conceptual model with a surprise index to describe whether long-term plant invader composition and dominance is predictable or stochastic after a system perturbation such as a removal experiment. Under extremely low resource availability, the surprise index is low, whereas under intermediate-level resource environments, invader dominance is more stochastic and the surprise index is high. At high resource levels, the surprise index is intermediate: Invaders are likely abundant in the environment but their response to a perturbation is more predictable than at intermediate resource levels. We suggest further testing across environmental gradients to determine key variables that dictate the predictability of postremoval invader composition.

  5. Viewpoint: Sustainability of piñon-juniper ecosystems - A unifying perspective of soil erosion thresholds

    Science.gov (United States)

    Davenport, David W.; Breshears, D.D.; Wilcox, B.P.; Allen, Craig D.

    1998-01-01

    Many pinon-juniper ecosystem in the western U.S. are subject to accelerated erosion while others are undergoing little or no erosion. Controversy has developed over whether invading or encroaching pinon and juniper species are inherently harmful to rangeland ecosystems. We developed a conceptual model of soil erosion in pinon-jumper ecosystems that is consistent with both sides of the controversy and suggests that the diverse perspectives on this issue arise from threshold effects operating under very different site conditions. Soil erosion rate can be viewed as a function of (1) site erosion potential (SEP), determined by climate, geomorphology and soil erodibility; and (2) ground cover. Site erosion potential and cove act synergistically to determine soil erosion rates, as evident even from simple USLE predictions of erosion. In pinon-juniper ecosystem with high SEP, the erosion rate is highly sensitive to ground cover and can cross a threshold so that erosion increases dramatically in response to a small decrease in cover. The sensitivity of erosion rate to SEP and cover can be visualized as a cusp catastrophe surface on which changes may occur rapidly and irreversibly. The mechanisms associated with a rapid shift from low to high erosion rate can be illustrated using percolation theory to incorporate spatial, temporal, and scale-dependent patterns of water storage capacity on a hillslope. Percolation theory demonstrates how hillslope runoff can undergo a threshold response to a minor change in storage capacity. Our conceptual model suggests that pinion and juniper contribute to accelerated erosion only under a limited range of site conditions which, however, may exist over large areas.

  6. 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

  7. Plant invasions in the Czech Republic: current state, introduction dynamics, invasive species and invaded habitats

    Czech Academy of Sciences Publication Activity Database

    Pyšek, Petr; Chytrý, M.; Pergl, Jan; Sádlo, Jiří; Wild, Jan

    2012-01-01

    Roč. 84, č. 3 (2012), s. 575-629 ISSN 0032-7786 R&D Projects: GA ČR(CZ) GAP504/11/1028 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : invasive species * invaded habitats * Czech Republic Subject RIV: EF - Botanics Impact factor: 2.833, year: 2012

  8. Predicting how altering propagule pressure changes establishment rates of biological invaders across species pools.

    Science.gov (United States)

    Brockerhoff, Eckehard G; Kimberley, Mark; Liebhold, Andrew M; Haack, Robert A; Cavey, Joseph F

    2014-03-01

    Biological invasions resulting from international trade can cause major environmental and economic impacts. Propagule pressure is perhaps the most important factor influencing establishment, although actual arrival rates of species are rarely recorded. Furthermore, the pool of potential invaders includes many species that vary in their arrival rate and establishment potential. Therefore, we stress that it is essential to consider the size and composition of species pools arriving from source regions when estimating probabilities of establishment and effects of pathway infestation rates. To address this, we developed a novel framework and modeling approach to enable prediction of future establishments in relation to changes in arrival rate across entire species pools. We utilized 13 828 border interception records from the United States and New Zealand for 444 true bark beetle (Scolytinae) and longhorned beetle (Cerambycidae) species detected between 1949 and 2008 as proxies for arrival rates to model the relationship between arrival and establishment rates. Nonlinearity in this relationship implies that measures intended to reduce the unintended transport of potential invaders (such as phytosanitary treatments) must be highly effective in order to substantially reduce the rate of future invasions, particularly if trade volumes continue to increase.

  9. 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

  10. Great Basin land managers provide detailed feedback about usefulness of two climate information web applications

    Directory of Open Access Journals (Sweden)

    Chad Zanocco

    Full Text Available Land managers in the Great Basin are working to maintain or restore sagebrush ecosystems as climate change exacerbates existing threats. Web applications delivering climate change and climate impacts information have the potential to assist their efforts. Although many web applications containing climate information currently exist, few have been co-produced with land managers or have incorporated information specifically focused on land managers’ needs. Through surveys and interviews, we gathered detailed feedback from federal, state, and tribal sagebrush land managers in the Great Basin on climate information web applications targeting land management. We found that a managers are searching for weather and climate information they can incorporate into their current management strategies and plans; b they are willing to be educated on how to find and understand climate related web applications; c both field and administrative-type managers want data for timescales ranging from seasonal to decadal; d managers want multiple levels of climate information, from simple summaries, to detailed descriptions accessible through the application; and e managers are interested in applications that evaluate uncertainty and provide projected climate impacts. Keywords: Great Basin, Sagebrush, Land management, Climate change, Web application, Co-production

  11. Contribution to the alien flora of Montenegro and Supplementum to the Preliminary list of plant invaders

    Directory of Open Access Journals (Sweden)

    Stešević, D.

    2013-12-01

    Full Text Available This contribution is based on the field observations from 2011 to 2013. Besides new data about distribution of some known plant invaders, one new alien species for the flora of Montenegro is reported- Solidago gigantea. This plant was recorded in 2011, on two distinct localities near the road side in peri-urban area of Nikšić and Mojkovac, in the vicinity of gardens, were it has been grown as ornamental. In 2012 survey, species was again reported for Mojkovac, but it disappeared from Nikšić, due to environmental changes caused by road construction. Remaining locality is placed near the Tara river bank, so considering ecological preferences (roadsides, disturbed river banks and moist soils, this species might become more frequent in the area. It is included into the EPPO list of invasive alien plants. In addition, alien plant Tagetes minuta is added to the preliminary list of plant invaders in Montenegro.

  12. Spatial pattern and scale influence invader demographic response to simulated precipitation change in an annual grassland community

    Science.gov (United States)

    It is important to predict which invasive species will benefit from future changes in climate, and thereby identify those invaders that need particular attention and prioritization of management efforts. Because establishment, persistence, and spread determine invasion success, this prediction requ...

  13. Induction concurrent chemoradiation therapy for invading apical non-small cell lung cancer

    International Nuclear Information System (INIS)

    Miyoshi, Shinichiro; Nakamura, Kenji

    2004-01-01

    Although non-small cell lung cancer (NSCLC) involving the superior sulcus has been generally treated with radiation therapy (RT) followed by surgery, local recurrence is still a big problem to be solved. We investigated a role of induction therapy, especially induction concurrent chemoradiation therapy (CRT), on the surgical results of this type of NSCLC. We retrospectively reviewed 30 patients with NSCLC invading the apex of the chest wall who underwent surgery from 1987 to 1996. Ten patients (57±8 years) received surgery alone, 9 (55±13 years) received RT (42±7 Gy) followed by surgery and 11 (51±9 years) received cisplatin based chemotherapy and RT (47±5 Gy) as an induction therapy. Two and 4-year survival rates were 30% and 20% in patients with surgery alone, 22% and 11% in patients with induction RT, and 73% and 53% in patients with induction CRT, respectively. The survival was significantly better in patients with induction CRT than those with induction RT or surgery alone. Univariate analysis demonstrated that curability (yes versus no: p=0.027) and induction therapy (surgery alone and RT versus CRT: p=0.0173) were significant prognostic factors. Multivariate analysis revealed that only induction therapy (p=0.0238) was a significant prognostic factor. Induction CRT seems to improve the survival in patients with NSCLC invading the apex of the chest wall compared with induction RT or surgery alone. (author)

  14. Darwin's naturalization hypothesis up-close: Intermountain grassland invaders differ morphologically and phenologically from native community dominants

    Science.gov (United States)

    Dean E. Pearson; Yvette K. Ortega; Samantha J. Sears

    2012-01-01

    Darwin's naturalization hypothesis predicts that successful invaders will tend to differ taxonomically from native species in recipient communities because less related species exhibit lower niche overlap and experience reduced biotic resistance. This hypothesis has garnered substantial support at coarse scales. However, at finer scales, the influence of traits...

  15. Fungal endophytes which invade insect galls: insect pathogens, benign saprophytes, or fungal inquilines?

    Science.gov (United States)

    Wilson, Dennis

    1995-08-01

    Fungi are frequently found within insect galls. However, the origin of these fungi, whether they are acting as pathogens, saprophytes invading already dead galls, or fungal inquilines which invade the gall but kill the gall maker by indirect means, is rarely investigated. A pathogenic role for these fungi is usually inferred but never tested. I chose the following leaf-galling-insect/host-plant pairs (1) a cynipid which forms two-chambered galls on the veins of Oregon white oak, (2) a cynipid which forms single-chambered galls on California coast live oak, and (3) an aphid which forms galls on narrowleaf cottonwood leaves. All pairs were reported to have fungi associated with dead insects inside the gall. These fungi were cultured and identified. For the two cynipids, all fungi found inside the galls were also present in the leaves as fungal endophytes. The cottonwood leaves examined did not harbor fungal endophytes. For the cynipid on Oregon white oak, the fungal endophyte grows from the leaf into the gall and infects all gall tissue but does not directly kill the gall maker. The insect dies as a result of the gall tissue dying from fungal infection. Therefore, the fungus acts as an inquiline. Approximately 12.5% of these galls die as a result of invasion by the fungal endophyte.

  16. Ecosystem-based management and the wealth of ecosystems

    Science.gov (United States)

    Yun, Seong Do; Hutniczak, Barbara; Abbott, Joshua K.; Fenichel, Eli P.

    2017-01-01

    We merge inclusive wealth theory with ecosystem-based management (EBM) to address two challenges in the science of sustainable management of ecosystems. First, we generalize natural capital theory to approximate realized shadow prices for multiple interacting natural capital stocks (species) making up an ecosystem. These prices enable ecosystem components to be better included in wealth-based sustainability measures. We show that ecosystems are best envisioned as portfolios of assets, where the portfolio’s performance depends on the performance of the underlying assets influenced by their interactions. Second, changes in ecosystem wealth provide an attractive headline index for EBM, regardless of whether ecosystem wealth is ultimately included in a broader wealth index. We apply our approach to the Baltic Sea ecosystem, focusing on the interacting community of three commercially important fish species: cod, herring, and sprat. Our results incorporate supporting services embodied in the shadow price of a species through its trophic interactions. Prey fish have greater shadow prices than expected based on market value, and predatory fish have lower shadow prices than expected based on market value. These results are because correctly measured shadow prices reflect interdependence and limits to substitution. We project that ecosystem wealth in the Baltic Sea fishery ecosystem generally increases conditional on the EBM-inspired multispecies maximum sustainable yield management beginning in 2017, whereas continuing the current single-species management generally results in declining wealth. PMID:28588145

  17. Ecosystem-based management and the wealth of ecosystems.

    Science.gov (United States)

    Yun, Seong Do; Hutniczak, Barbara; Abbott, Joshua K; Fenichel, Eli P

    2017-06-20

    We merge inclusive wealth theory with ecosystem-based management (EBM) to address two challenges in the science of sustainable management of ecosystems. First, we generalize natural capital theory to approximate realized shadow prices for multiple interacting natural capital stocks (species) making up an ecosystem. These prices enable ecosystem components to be better included in wealth-based sustainability measures. We show that ecosystems are best envisioned as portfolios of assets, where the portfolio's performance depends on the performance of the underlying assets influenced by their interactions. Second, changes in ecosystem wealth provide an attractive headline index for EBM, regardless of whether ecosystem wealth is ultimately included in a broader wealth index. We apply our approach to the Baltic Sea ecosystem, focusing on the interacting community of three commercially important fish species: cod, herring, and sprat. Our results incorporate supporting services embodied in the shadow price of a species through its trophic interactions. Prey fish have greater shadow prices than expected based on market value, and predatory fish have lower shadow prices than expected based on market value. These results are because correctly measured shadow prices reflect interdependence and limits to substitution. We project that ecosystem wealth in the Baltic Sea fishery ecosystem generally increases conditional on the EBM-inspired multispecies maximum sustainable yield management beginning in 2017, whereas continuing the current single-species management generally results in declining wealth.

  18. Repelling invaders: Hawaiian foresters use ecology to counter invasive species

    Science.gov (United States)

    Jim Kling; Julie Featured: Denslow; Tracy Johnson; Susan Cordell

    2008-01-01

    The Hawaiian Islands are one of the United States' most treasured natural resources. Their natural beauty attracts legions of visitors every year, and they represent a unique set of ecosystems. Despite their limited geographic size, Hawai‘i hosts a remarkable range of habitats. On some islands, dry tropical forest, wet rain forest, and alpine ecosystems are found...

  19. The fungus that came in from the cold: dry rot's pre-adapted ability to invade buildings.

    Science.gov (United States)

    Balasundaram, S V; Hess, J; Durling, M B; Moody, S C; Thorbek, L; Progida, C; LaButti, K; Aerts, A; Barry, K; Grigoriev, I V; Boddy, L; Högberg, N; Kauserud, H; Eastwood, D C; Skrede, I

    2018-03-01

    Many organisms benefit from being pre-adapted to niches shaped by human activity, and have successfully invaded man-made habitats. One such species is the dry rot fungus Serpula lacrymans, which has a wide distribution in buildings in temperate and boreal regions, where it decomposes coniferous construction wood. Comparative genomic analyses and growth experiments using this species and its wild relatives revealed that S. lacrymans evolved a very effective brown rot decay compared to its wild relatives, enabling an extremely rapid decay in buildings under suitable conditions. Adaptations in intracellular transport machineries promoting hyphal growth, and nutrient and water transport may explain why it is has become a successful invader of timber in houses. Further, we demonstrate that S. lacrymans has poor combative ability in our experimental setup, compared to other brown rot fungi. In sheltered indoor conditions, the dry rot fungus may have limited encounters with other wood decay fungi compared to its wild relatives. Overall, our analyses indicate that the dry rot fungus is an ecological specialist with poor combative ability against other fungi.

  20. A native species with invasive behaviour in coastal dunes: evidence for progressing decay and homogenization of habitat types

    DEFF Research Database (Denmark)

    Nielsen, Knud Erik; Degn, Hans Jørgen; Damgaard, Christian

    2011-01-01

    A new species has recently invaded coastal dune ecosystems in North West Europe. The native and expansive inland grass, Deschampsia flexuosa, progressively dominating inland heaths, has recently invaded coastal dunes in Denmark, occasionally even as a dominant species. A total of 222 coastal loca...

  1. Faster N Release, but Not C Loss, From Leaf Litter of Invasives Compared to Native Species in Mediterranean Ecosystems

    Directory of Open Access Journals (Sweden)

    Guido Incerti

    2018-04-01

    Full Text Available Plant invasions can have relevant impacts on biogeochemical cycles, whose extent, in Mediterranean ecosystems, have not yet been systematically assessed comparing litter carbon (C and nitrogen (N dynamics between invasive plants and native communities. We carried out a 1-year litterbag experiment in 4 different plant communities (grassland, sand dune, riparian and mixed forests on 8 invasives and 24 autochthonous plant species, used as control. Plant litter was characterized for mass loss, N release, proximate lignin and litter chemistry by 13C CPMAS NMR. Native and invasive species showed significant differences in litter chemical traits, with invaders generally showing higher N concentration and lower lignin/N ratio. Mass loss data revealed no consistent differences between native and invasive species, although some woody and vine invaders showed exceptionally high decomposition rate. In contrast, N release rate from litter was faster for invasive plants compared to native species. N concentration, lignin content and relative abundance of methoxyl and N-alkyl C region from 13C CPMAS NMR spectra were the parameters that better explained mass loss and N mineralization rates. Our findings demonstrate that during litter decomposition invasive species litter has no different decomposition rates but greater N release rate compared to natives. Accordingly, invasives are expected to affect N cycle in Mediterranean plant communities, possibly promoting a shift of plant assemblages.

  2. Control fast or control smart: When should invading pathogens be controlled?

    Directory of Open Access Journals (Sweden)

    Robin N Thompson

    2018-02-01

    Full Text Available The intuitive response to an invading pathogen is to start disease management as rapidly as possible, since this would be expected to minimise the future impacts of disease. However, since more spread data become available as an outbreak unfolds, processes underpinning pathogen transmission can almost always be characterised more precisely later in epidemics. This allows the future progression of any outbreak to be forecast more accurately, and so enables control interventions to be targeted more precisely. There is also the chance that the outbreak might die out without any intervention whatsoever, making prophylactic control unnecessary. Optimal decision-making involves continuously balancing these potential benefits of waiting against the possible costs of further spread. We introduce a generic, extensible data-driven algorithm based on parameter estimation and outbreak simulation for making decisions in real-time concerning when and how to control an invading pathogen. The Control Smart Algorithm (CSA resolves the trade-off between the competing advantages of controlling as soon as possible and controlling later when more information has become available. We show-using a generic mathematical model representing the transmission of a pathogen of agricultural animals or plants through a population of farms or fields-how the CSA allows the timing and level of deployment of vaccination or chemical control to be optimised. In particular, the algorithm outperforms simpler strategies such as intervening when the outbreak size reaches a pre-specified threshold, or controlling when the outbreak has persisted for a threshold length of time. This remains the case even if the simpler methods are fully optimised in advance. Our work highlights the potential benefits of giving careful consideration to the question of when to start disease management during emerging outbreaks, and provides a concrete framework to allow policy-makers to make this decision.

  3. Control fast or control smart: When should invading pathogens be controlled?

    Science.gov (United States)

    Thompson, Robin N; Gilligan, Christopher A; Cunniffe, Nik J

    2018-02-01

    The intuitive response to an invading pathogen is to start disease management as rapidly as possible, since this would be expected to minimise the future impacts of disease. However, since more spread data become available as an outbreak unfolds, processes underpinning pathogen transmission can almost always be characterised more precisely later in epidemics. This allows the future progression of any outbreak to be forecast more accurately, and so enables control interventions to be targeted more precisely. There is also the chance that the outbreak might die out without any intervention whatsoever, making prophylactic control unnecessary. Optimal decision-making involves continuously balancing these potential benefits of waiting against the possible costs of further spread. We introduce a generic, extensible data-driven algorithm based on parameter estimation and outbreak simulation for making decisions in real-time concerning when and how to control an invading pathogen. The Control Smart Algorithm (CSA) resolves the trade-off between the competing advantages of controlling as soon as possible and controlling later when more information has become available. We show-using a generic mathematical model representing the transmission of a pathogen of agricultural animals or plants through a population of farms or fields-how the CSA allows the timing and level of deployment of vaccination or chemical control to be optimised. In particular, the algorithm outperforms simpler strategies such as intervening when the outbreak size reaches a pre-specified threshold, or controlling when the outbreak has persisted for a threshold length of time. This remains the case even if the simpler methods are fully optimised in advance. Our work highlights the potential benefits of giving careful consideration to the question of when to start disease management during emerging outbreaks, and provides a concrete framework to allow policy-makers to make this decision.

  4. Management process invaded Ames as the Center shifted from NACA to NASA oversight. Ames constructed

    Science.gov (United States)

    1968-01-01

    Management process invaded Ames as the Center shifted from NACA to NASA oversight. Ames constructed a review room in its headquarters building where, in the graphical style that prevailed in the 1960's, Ames leadership could review progress against schedule, budget and performance measures. Shown, in October 1965 is Merrill Mead chief of Ames' program and resources office. (for H Julian Allen Retirement album)

  5. Ecosystem services in the face of invasion: the persistence of native and nonnative spiders in an agricultural landscape.

    Science.gov (United States)

    Hogg, Brian N; Daane, Kent M

    2011-03-01

    The presence of intact natural ecosystems in agricultural landscapes can mitigate losses in the diversity of natural enemies and enhance ecosystem services. However, native natural enemies may fail to persist in agroecosystems if invaders dominate species interactions. In this study, native and nonnative spiders were sampled along transects that extended from oak woodland and riparian zones into surrounding California vineyards, to assess the role of natural habitat as a source for spider biodiversity in the vineyard landscape, and to compare the dominance of exotic Cheiracanthium spiders between habitats. Many spider species were more abundant in natural habitat than in vineyards, and numbers of spiders and spider species within vineyards were higher at the vineyard edge adjacent to oak woodland. These results suggest that natural habitat is a key source for spiders in vineyards. The positive effect of oak woodland on the vineyard spider community extended only to the vineyard edge, however. Proportions of Cheiracanthium spiders increased dramatically in the vineyard, while numbers of native wandering spiders (the native ecological homologues of Cheiracanthium spiders) decreased. Dispersal limitation and strong habitat preferences may have prevented native wandering spiders from establishing far from the vineyard edge. Exotic Cheiracanthium spiders, in contrast, may possess specific adaptations to vineyards or to a wide range of habitats. Results suggest that the ecosystem services provided by intact natural habitat may be limited in agricultural landscapes that are dominated by invasive species.

  6. Ecosystem water availability in juniper versus sagebrush snow-dominated rangelands

    Science.gov (United States)

    Western Juniper (J. occidentalis Hook.) now dominates over 3.6 million ha of rangeland in the Intermountain Western US. Critical ecological relationships among snow distribution, water budgets, plant community transitions, and habitat requirements for wildlife, such as sage grouse, remain poorly und...

  7. Recurrent malignant pilomatrixoma invading the cranial cavity: improved local control with adjuvant radiation

    International Nuclear Information System (INIS)

    Aherne, N. J.; Fitzpatrick, D. A.; Armstrong, J. G.; Gibbons, D.; Collins, C. D.

    2009-01-01

    Full text: We report the case of a 41-year-old mentally retarded male with recurrent pilomatrix carcinoma of the occipital region which invaded the occipital bone, left cerebellum and left temporal lobe. At his initial presentation the patient had a craniotomy and subtotal excision of the lesion with positive margins. He received no adjuvant therapy. After an early intracranial recurrence he had subtotal debulking and was referred for external beam radiotherapy. At 27 months follow-up after adjuvant external beam radiotherapy the intracranial component has not progressed and the patient remains clinically well

  8. Ecosystem Vulnerability Review: Proposal of an Interdisciplinary Ecosystem Assessment Approach

    Science.gov (United States)

    Weißhuhn, Peter; Müller, Felix; Wiggering, Hubert

    2018-06-01

    To safeguard the sustainable use of ecosystems and their services, early detection of potentially damaging changes in functional capabilities is needed. To support a proper ecosystem management, the analysis of an ecosystem's vulnerability provide information on its weaknesses as well as on its capacity to recover after suffering an impact. However, the application of the vulnerability concept to ecosystems is still an emerging topic. After providing background on the vulnerability concept, we summarize existing ecosystem vulnerability research on the basis of a systematic literature review with a special focus on ecosystem type, disciplinary background, and more detailed definition of the ecosystem vulnerability components. Using the Web of ScienceTM Core Collection, we overviewed the literature from 1991 onwards but used the 5 years from 2011 to 2015 for an in-depth analysis, including 129 articles. We found that ecosystem vulnerability analysis has been applied most notably in conservation biology, climate change research, and ecological risk assessments, pinpointing a limited spreading across the environmental sciences. It occurred primarily within marine and freshwater ecosystems. To avoid confusion, we recommend using the unambiguous term ecosystem vulnerability rather than ecological, environmental, population, or community vulnerability. Further, common ground has been identified, on which to define the ecosystem vulnerability components exposure, sensitivity, and adaptive capacity. We propose a framework for ecosystem assessments that coherently connects the concepts of vulnerability, resilience, and adaptability as different ecosystem responses. A short outlook on the possible operationalization of the concept by ecosystem vulnerabilty indices, and a conclusion section complete the review.

  9. Preface: Ecosystem services, ecosystem health and human communities

    Science.gov (United States)

    Plag, Hans-Peter

    2018-04-01

    This special issue contains a collection of manuscripts that were originally intended to be included in the special issue on "Physics and Economics of Ecosystem Services Flows" (Volume 101, guest editors H. Su, J. Dong and S. Nagarajan) and "Biogeochemical Processes in the Changing Wetland Environment" (Volume 103, guest editors J. Bai, L. Huang and H. Gao). All of them are addressing issues related to ecosystem services in different settings. Ecosystem services are of high value for both the ecosystems and human communities, and understanding the impacts of environmental processes and human activities on ecosystems is of fundamental importance for the preservation of these services.

  10. Use of Plant Hydraulic Theory to Predict Ecosystem Fluxes Across Mountainous Gradients in Environmental Controls and Insect Disturbances

    Science.gov (United States)

    Ewers, B. E.; Pendall, E.; Reed, D. E.; Barnard, H. R.; Whitehouse, F.; Frank, J. M.; Massman, W. J.; Brooks, P. D.; Biederman, J. A.; Harpold, A. A.; Naithani, K. J.; Mitra, B.; Mackay, D. S.; Norton, U.; Borkhuu, B.

    2011-12-01

    While mountainous areas are critical for providing numerous ecosystem benefits at the regional scale, the strong gradients in environmental controls make predictions difficult. A key part of the problem is quantifying and predicting the feedback between mountain gradients and plant function which then controls ecosystem cycling. The emerging theory of plant hydraulics provides a rigorous yet simple platform from which to generate testable hypotheses and predictions of ecosystem pools and fluxes. Plant hydraulic theory predicts that plant controls over carbon, water, energy and nutrient fluxes can be derived from the limitation of plant water transport from the soil through xylem and out of stomata. In addition, the limit to plant water transport can be predicted by combining plant structure (e.g. xylem diameters or root-to-shoot ratios) and plant function (response of stomatal conductance to vapor pressure deficit or root vulnerability to cavitation). We evaluate the predictions of the plant hydraulic theory by testing it against data from a mountain gradient encompassing sagebrush steppe through subalpine forests (2700 to 3400 m). We further test the theory by predicting the carbon, water and nutrient exchanges from several coniferous trees in the same gradient that are dying from xylem dysfunction caused by blue-stain fungi carried by bark beetles. The common theme of both of these data sets is a change in water limitation caused by either changing precipitation along the mountainous gradient or lack of access to soil water from xylem-occluding fungi. Across all of the data sets which range in scale from individual plants to hillslopes, the data fit the predictions of plant hydraulic theory. Namely, there was a proportional tradeoff between the reference canopy stomatal conductance to water vapor and the sensitivity of that conductance to vapor pressure deficit that quantitatively fits the predictions of plant hydraulic theory. Incorporating this result into

  11. Epizootic ulcerative syndrome: Exotic fish disease threatens Africa’s aquatic ecosystems

    Directory of Open Access Journals (Sweden)

    Karl D.A. Huchzermeyer

    2012-09-01

    Full Text Available In late 2006 an unusual ulcerative condition in wild fish was reported for the first time in Africa from the Chobe and upper Zambezi Rivers in Botswana and Namibia. Concern increased with subsistence fishermen reporting large numbers of ulcerated fish in their catches. In April 2007 the condition was confirmed as an outbreak of epizootic ulcerative syndrome (EUS. The causative agent, Aphanomyces invadans, is a pathogenic water mould of fish that shows little host specificity. Ulcers follow infection of tissues by oomycete zoospores, resulting in a granulomatous inflammation associated with invading oomycete hyphae. Granulomatous tracts surrounding oomycete hyphae within the necrotic tissues characterise the diagnostic histological picture. The upper Zambezi floodplain at the confluence with the Chobe River spans the four countries of Botswana, Namibia, Zambia and Zimbabwe, making disease control a challenge. The floodplain ecosystem supports a high fish diversity of around 80 species, and is an important breeding and nursery ground. The annual cycle of flooding brings about changes in water quality that are thought to favour the infectivity of A. invadans, with diseased fish appearing soon after the plains become flooded. Since 2006 the disease has spread rapidly upstream along the upper Zambezi and its tributaries. By 2010 the disease was reported from the Okavango Delta in Botswana and in 2011 from the Western Cape Province of South Africa. EUS has the potential to disrupt floodplain ecosystems elsewhere in Africa where high fish diversity forms the basis of subsistence fisheries and local economies, and is a direct threat to freshwater fish culture.

  12. Genomic signatures of rapid adaptive evolution in the bluespotted cornetfish, a Mediterranean Lessepsian invader.

    Science.gov (United States)

    Bernardi, Giacomo; Azzurro, Ernesto; Golani, Daniel; Miller, Michael Ryan

    2016-07-01

    Biological invasions are increasingly creating ecological and economical problems both on land and in aquatic environments. For over a century, the Mediterranean Sea has steadily been invaded by Indian Ocean/Red Sea species (called Lessepsian invaders) via the Suez Canal, with a current estimate of ~450 species. The bluespotted cornetfish, Fistularia commersonii, considered a 'Lessepsian sprinter', entered the Mediterranean in 2000 and by 2007 had spread through the entire basin from Israel to Spain. The situation is unique and interesting both because of its unprecedented rapidity and by the fact that it took this species c. 130 years to immigrate into the Mediterranean. Using genome scans, with restriction site-associated DNA (RAD) sequencing, we evaluated neutral and selected genomic regions for Mediterranean vs. Red Sea cornetfish individuals. We found that few fixed neutral changes were detectable among populations. However, almost half of the genes associated with the 47 outlier loci (potentially under selection) were related to disease resistance and osmoregulation. Due to the short time elapsed from the beginning of the invasion to our sampling, we interpret these changes as signatures of rapid adaptation that may be explained by several mechanisms including preadaptation and strong local selection. Such genomic regions are therefore good candidates to further study their role in invasion success. © 2016 John Wiley & Sons Ltd.

  13. Efficacy of prophylactic splenectomy for proximal advanced gastric cancer invading greater curvature.

    Science.gov (United States)

    Ohkura, Yu; Haruta, Shusuke; Shindoh, Junichi; Tanaka, Tsuyoshi; Ueno, Masaki; Udagawa, Harushi

    2017-05-25

    For proximal gastric cancer invading the greater curvature, concomitant splenectomy is frequently performed to secure the clearance of lymph node metastases. However, prognostic impact of prophylactic splenectomy remains unclear. The aim of this study was to clarify the oncological significance of prophylactic splenectomy for advanced proximal gastric cancer invading the greater curvature. Retrospective review of 108 patients who underwent total or subtotal gastrectomy for advanced proximal gastric cancer involving the greater curvature was performed. Short-term and long-term outcomes were compared between the patients who underwent splenectomy (n = 63) and those who did not (n = 45). Patients who underwent splenectomy showed higher amount of blood loss (538 vs. 450 mL, p = 0.016) and morbidity rate (30.2 vs. 13.3, p = 0.041) compared with those who did not undergo splenectomy. In particular, pancreas-related complications were frequently observed among patients who received splenectomy (17.4 vs. 0%, p = 0.003). However, no significant improvement of long-term outcomes were confirmed in the cases with splenectomy (5-year recurrence-free rate, 60.2 vs. 67.3%; p = 0.609 and 5-year overall survival rates, 63.7 vs. 73.6%; p = 0.769). On the other hand, splenectomy was correlated with marginally better survival in patients with Borrmann type 1 or 2 gastric cancer (p = 0.072). For advanced proximal gastric cancer involving the greater curvature, prophylactic splenectomy may have no significant prognostic impact despite the increased morbidity rate after surgery. Such surgical procedure should be avoided as long as lymph node involvement is not evident.

  14. Reconstruction of a Marjolin Ulcer Defect of the Scalp Invading Brain and Causing Brain Abscess Formation Using Free Latissimus Dorsi Flap.

    Science.gov (United States)

    Tenekeci, Goktekin; Sari, Alper; Hamzaoglu, Vural; Ozalp, Hakan

    2017-07-01

    Marjolin ulcers are known as aggressive malignant tumors that mostly arise over chronic wounds and cutaneous scars. Brain abscess is a serious medical condition that requires surgical drainage along with antibiotic treatment. Here, we report a case with a Marjolin ulcer located over the right parietal bone with intracranial abscess formation along with tumor invasion into brain parenchyma. This patient was a 64-year-old man and had a 4 × 4 cm open wound on his scalp from which a purulent discharge was coming. This wound required surgical excision with security margins, resection of bone, evacuation of the cystic cavity, and excision of the walls of the cystic cavity, which were invaded by the tumor. Duraplasty and reconstruction of the defect with a free lattisimus dorsi flap are performed. To the best of our knowledge, the case reported here is unique because of the formation of brain abscess in the background of a long-lasting Marjolin ulcer invading brain parenchyma. It must be remembered that on the background of cutaneous scars located over the scalp, a Marjolin ulcer may develop, and if left untreated, tumor cells may invade even the brain parenchyma. Long-term asymptomatic brain infections may also accompany the given scenario, and complicate differential diagnosis.

  15. Mangrove forests: a tough system to invade

    Science.gov (United States)

    Ariel E. Lugo

    1998-01-01

    Tropical forests are the most species-rich forests in the world. As many as 225 tree species per hectare have been reported in these ecosystems, values that are equivalent to almost finding a different tree species every other tree encountered in the forest. Under some conditions, tree species richness decreases in tropical forests. For example, Hart et al. (1989)...

  16. Effects of Bromus tectorum invasion on microbial carbon and nitrogen cycling in two adjacent undisturbed arid grassland communities

    Science.gov (United States)

    Schaeffer, Sean M.; Ziegler, Susan E.; Belnap, Jayne; Evans, R.D.

    2012-01-01

    Soil nitrogen (N) is an important component in maintaining ecosystem stability, and the introduction of non-native plants can alter N cycling by changing litter quality and quantity, nutrient uptake patterns, and soil food webs. Our goal was to determine the effects of Bromus tectorum (C3) invasion on soil microbial N cycling in adjacent non-invaded and invaded C3 and C4 native arid grasslands. We monitored resin-extractable N, plant and soil δ13C and δ15N, gross rates of inorganic N mineralization and consumption, and the quantity and isotopic composition of microbial phospholipid biomarkers. In invaded C3 communities, labile soil organic N and gross and net rates of soil N transformations increased, indicating an increase in overall microbial N cycling. In invaded C4 communities labile soil N stayed constant, but gross N flux rates increased. The δ13C of phospholipid biomarkers in invaded C4 communities showed that some portion of the soil bacterial population preferentially decomposed invader C3-derived litter over that from the native C4 species. Invasion in C4 grasslands also significantly decreased the proportion of fungal to bacterial phospholipid biomarkers. Different processes are occurring in response to B. tectorum invasion in each of these two native grasslands that: 1) alter the size of soil N pools, and/or 2) the activity of the microbial community. Both processes provide mechanisms for altering long-term N dynamics in these ecosystems and highlight how multiple mechanisms can lead to similar effects on ecosystem function, which may be important for the construction of future biogeochemical process models.

  17. Integrating novel chemical weapons and evolutionarily increased competitive ability in success of a tropical invader.

    Science.gov (United States)

    Zheng, Yu-Long; Feng, Yu-Long; Zhang, Li-Kun; Callaway, Ragan M; Valiente-Banuet, Alfonso; Luo, Du-Qiang; Liao, Zhi-Yong; Lei, Yan-Bao; Barclay, Gregor F; Silva-Pereyra, Carlos

    2015-02-01

    The evolution of increased competitive ability (EICA) hypothesis and the novel weapons hypothesis (NWH) are two non-mutually exclusive mechanisms for exotic plant invasions, but few studies have simultaneously tested these hypotheses. Here we aimed to integrate them in the context of Chromolaena odorata invasion. We conducted two common garden experiments in order to test the EICA hypothesis, and two laboratory experiments in order to test the NWH. In common conditions, C. odorata plants from the nonnative range were better competitors but not larger than plants from the native range, either with or without the experimental manipulation of consumers. Chromolaena odorata plants from the nonnative range were more poorly defended against aboveground herbivores but better defended against soil-borne enemies. Chromolaena odorata plants from the nonnative range produced more odoratin (Eupatorium) (a unique compound of C. odorata with both allelopathic and defensive activities) and elicited stronger allelopathic effects on species native to China, the nonnative range of the invader, than on natives of Mexico, the native range of the invader. Our results suggest that invasive plants may evolve increased competitive ability after being introduced by increasing the production of novel allelochemicals, potentially in response to naïve competitors and new enemy regimes. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  18. Sonoran Desert ecosystem transformation by a C4 grass without the grass/fire cycle

    Science.gov (United States)

    Olsson, Aaryn D.; Betancourt, Julio; McClaran, Mitchel P.; Marsh, Stuart E.

    2012-01-01

    Aim Biological invasions facilitate ecosystem transformation by altering the structure and function, diversity, dominance and disturbance regimes. A classic case is the grass–fire cycle in which grass invasion increases the frequency, scale and/or intensity of wildfires and promotes the continued invasion of invasive grasses. Despite wide acceptance of the grass–fire cycle, questions linger about the relative roles that interspecific plant competition and fire play in ecosystem transformations. Location Sonoran Desert Arizona Upland of the Santa Catalina Mountains, Arizona, USA. Methods We measured species cover, density and saguaro (Carnegiea gigantea) size structure along gradients of Pennisetum ciliare invasion at 10 unburned/ungrazed P. ciliare patches. Regression models quantified differences in diversity, cover and density with respect to P. ciliare cover, and residence time and a Fisher's exact test detected demographic changes in saguaro populations. Because P. ciliare may have initially invaded locations that were both more invasible and less diverse, we ran analyses with and without the plots in which initial infestations were located. Results Richness and diversity decreased with P. ciliare cover as did cover and density of most dominant species. Richness and diversity declined with increasing time since invasion, suggesting an ongoing transformation. The proportion of old-to-young Carnegiea gigantea was significantly lower in plots with dominant P. ciliare cover. Main conclusions Rich desert scrub (15–25 species per plot) was transformed into depauperate grassland (2–5 species per plot) within 20 years following P. ciliare invasion without changes to the fire regime. While the onset of a grass–fire cycle may drive ecosystem change in the later stages and larger scales of grass invasions of arid lands, competition by P. ciliare can drive small-scale transformations earlier in the invasion. Linking competition-induced transformation rates with

  19. Ecosystem services as a common language for coastal ecosystem-based management.

    Science.gov (United States)

    Granek, Elise F; Polasky, Stephen; Kappel, Carrie V; Reed, Denise J; Stoms, David M; Koch, Evamaria W; Kennedy, Chris J; Cramer, Lori A; Hacker, Sally D; Barbier, Edward B; Aswani, Shankar; Ruckelshaus, Mary; Perillo, Gerardo M E; Silliman, Brian R; Muthiga, Nyawira; Bael, David; Wolanski, Eric

    2010-02-01

    Ecosystem-based management is logistically and politically challenging because ecosystems are inherently complex and management decisions affect a multitude of groups. Coastal ecosystems, which lie at the interface between marine and terrestrial ecosystems and provide an array of ecosystem services to different groups, aptly illustrate these challenges. Successful ecosystem-based management of coastal ecosystems requires incorporating scientific information and the knowledge and views of interested parties into the decision-making process. Estimating the provision of ecosystem services under alternative management schemes offers a systematic way to incorporate biogeophysical and socioeconomic information and the views of individuals and groups in the policy and management process. Employing ecosystem services as a common language to improve the process of ecosystem-based management presents both benefits and difficulties. Benefits include a transparent method for assessing trade-offs associated with management alternatives, a common set of facts and common currency on which to base negotiations, and improved communication among groups with competing interests or differing worldviews. Yet challenges to this approach remain, including predicting how human interventions will affect ecosystems, how such changes will affect the provision of ecosystem services, and how changes in service provision will affect the welfare of different groups in society. In a case study from Puget Sound, Washington, we illustrate the potential of applying ecosystem services as a common language for ecosystem-based management.

  20. Ecosystem Services

    Science.gov (United States)

    Ecosystem goods and services are the many life-sustaining benefits we receive from nature and contribute to environmental and human health and well-being. Ecosystem-focused research will develop methods to measure ecosystem goods and services.

  1. Species replacement by a nonnative salmonid alters ecosystem function by reducing prey subsidies that support riparian spiders

    Science.gov (United States)

    Benjamin, J.R.; Fausch, K.D.; Baxter, C.V.

    2011-01-01

    Replacement of a native species by a nonnative can have strong effects on ecosystem function, such as altering nutrient cycling or disturbance frequency. Replacements may cause shifts in ecosystem function because nonnatives establish at different biomass, or because they differ from native species in traits like foraging behavior. However, no studies have compared effects of wholesale replacement of a native by a nonnative species on subsidies that support consumers in adjacent habitats, nor quantified the magnitude of these effects. We examined whether streams invaded by nonnative brook trout (Salvelinus fontinalis) in two regions of the Rocky Mountains, USA, produced fewer emerging adult aquatic insects compared to paired streams with native cutthroat trout (Oncorhynchus clarkii), and whether riparian spiders that depend on these prey were less abundant along streams with lower total insect emergence. As predicted, emergence density was 36% lower from streams with the nonnative fish. Biomass of brook trout was higher than the cutthroat trout they replaced, but even after accounting for this difference, emergence was 24% lower from brook trout streams. More riparian spiders were counted along streams with greater total emergence across the water surface. Based on these results, we predicted that brook trout replacement would result in 6-20% fewer spiders in the two regions. When brook trout replace cutthroat trout, they reduce cross-habitat resource subsidies and alter ecosystem function in stream-riparian food webs, not only owing to increased biomass but also because traits apparently differ from native cutthroat trout. ?? 2011 Springer-Verlag.

  2. Isolated Retroperitoneal Hydatid Cyst Invading Splenic Hilum

    Directory of Open Access Journals (Sweden)

    Safak Ozturk

    2014-01-01

    Full Text Available Introduction. Hydatid disease (HD is an infestation that is caused by the larval stage of Echinococcus granulosus. The liver is affected in approximately two-thirds of patients, the lungs in 25%, and other organs in a small proportion. Primary retroperitoneal hydatid cyst is extremely rare. The most common complaint is abdominal pain; however, the clinical features of HD may be generally dependent on the location of the cyst. Case Presentation. A 43-year-old female was admitted with the complaint of abdominal pain. Her physical examination was normal. Computed tomography (CT revealed a 17 × 11 cm cystic lesion, with a thick and smooth wall that is located among the left liver lobe, diaphragm, spleen, tail of the pancreas, and transverse colon and invading the splenic hilum. Total cystectomy and splenectomy were performed. Pathological examination was reported as cyst hydatid. Discussion. Cysts in the peritoneal cavity are mainly the result of the spontaneous or traumatic rupture of concomitant hepatic cysts or surgical inoculation of a hepatic cyst. Serological tests contribute to diagnosis. In symptomatic and large hydatid peritoneal cysts, surgical resection is the only curative treatment. Total cystectomy is the gold standard. Albendazole or praziquantel is indicated for inoperable and disseminated cases. Percutaneous aspiration, injection, and reaspiration (PAIR technique is another nonsurgical option.

  3. Predicting invasion in grassland ecosystems: is exotic dominance the real embarrassment of richness?

    Energy Technology Data Exchange (ETDEWEB)

    Seabloom, Eric W. [Department of Ecology, Evolution, and Behavior, University of MN, St. Paul MN 55108 USA; Borer, Elizabeth T. [Department of Ecology, Evolution, and Behavior, University of MN, St. Paul MN 55108 USA; Buckley, Yvonne [ARC Centre of Excellence for Environmental Decisions, School of Biological Sciences, The University of Queensland, Brisbane Queensland 4072 Australia; Cleland, Elsa E. [Ecology, Behavior & Evolution Section, University of California, San Diego La Jolla CA 92093 USA; Davies, Kendi [Department of Ecology and Evolutionary Biology, University of Colorado, Boulder CO 80309 USA; Firn, Jennifer [Queensland University of Technology, Biogeosciences, Brisbane Queensland 4000 Australia; Harpole, W. Stanley [Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames IA 50011 USA; Hautier, Yann [Department of Ecology, Evolution, and Behavior, University of MN, St. Paul MN 55108 USA; Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190 CH-8057 Zurich Switzerland; Lind, Eric [Department of Ecology, Evolution, and Behavior, University of MN, St. Paul MN 55108 USA; MacDougall, Andrew [Department of Integrative Biology, University of Guelph, Guelph Ontario N1G 2W1 Canada; Orrock, John L. [Department of Zoology, University of Wisconsin, Madison WI 53706 USA; Prober, Suzanne M. [CSIRO Ecosystem Sciences, Private Bag 5 Wembley WA 6913 Australia; Adler, Peter [Department of Wildland Resources and the Ecology Center, Utah State University, Logan UT 84322 USA; Alberti, Juan [Instituto de Investigaciones Marinas y Costeras (UNMdP-CONICET), Mar del Plata Argentina; Michael Anderson, T. [Department of Biology, Wake Forest University, Winston-Salem NC 27109 USA; Bakker, Jonathan D. [School of Environmental and Forest Sciences, University of Washington, Seattle WA 98195-4115 USA; Biederman, Lori A. [Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames IA 50011 USA; Blumenthal, Dana [Rangeland Resources Research Unit, USDA Agricultural Research Service, Fort Collins CO 80526 USA; Brown, Cynthia S. [Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins CO 80523 USA; Brudvig, Lars A. [Department of Plant Biology, Michigan State University, East Lansing MI 48824 USA; Caldeira, Maria [Centro de Estudos Florestais, Instituto Superior de Agronomia, Technical University of Lisbon, Lisbon Portugal; Chu, Chengjin [School of Life Sciences, Lanzhou University, Lanzhou 730000 China; Crawley, Michael J. [Department of Biology, Imperial College London, Silwood Park Ascot SL5 7PY UK; Daleo, Pedro [Instituto de Investigaciones Marinas y Costeras (UNMdP-CONICET), Mar del Plata Argentina; Damschen, Ellen I. [Department of Zoology, University of Wisconsin, Madison WI 53706 USA; D' Antonio, Carla M. [Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara CA 93106 USA; DeCrappeo, Nicole M. [U.S. Geological Survey Forest and Rangeland Ecosystem Science Center, Corvallis OR 97331 USA; Dickman, Chris R. [Desert Ecology Research Group, School of Biological Sciences, University of Sydney, Sydney NSW 2006 Australia; Du, Guozhen [School of Life Sciences, Lanzhou University, Lanzhou 730000 China; Fay, Philip A. [USDA-ARS Grassland Soil and Water Research Lab, Temple TX 76502 USA; Frater, Paul [Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames IA 50011 USA; Gruner, Daniel S. [Department of Entomology, University of Maryland, College Park MD 20742 USA; Hagenah, Nicole [School of Life Sciences, University of KwaZulu-Natal, Scottsville Pietermaritzburg 3209 South Africa; Department of Ecology, Evolutionary Biology, Yale University, New Haven CT 06520 USA; Hector, Andrew [Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190 CH-8057 Zurich Switzerland; Helm, Aveliina [Institute of Ecology and Earth Sciences, University of Tartu, Tartu Estonia; Hillebrand, Helmut [Institute for Chemistry and Biology of the Marine Environment, Carl-von-Ossietzky University, Wilhelmshaven Germany; Hofmockel, Kirsten S. [Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames IA 50011 USA; Humphries, Hope C. [INSTAAR, University of Colorado, Boulder CO 80309-0450 USA; Iribarne, Oscar [Instituto de Investigaciones Marinas y Costeras (UNMdP-CONICET), Mar del Plata Argentina; Jin, Virginia L. [USDA-ARS Agroecosystem Management Research Unit, Lincoln NE 68583 USA; Kay, Adam [Biology Department, University of St. Thomas, Saint Paul MN 55105 USA; Kirkman, Kevin P. [School of Life Sciences, University of KwaZulu-Natal, Scottsville Pietermaritzburg 3209 South Africa; Klein, Julia A. [Department Forest, Rangeland & Watershed Stewardship, Colorado State University, Fort Collins CO 80523-1472 USA; Knops, Johannes M. H. [School of Biological Sciences, University of Nebraska, Lincoln NE 68588 USA; La Pierre, Kimberly J. [Department of Ecology, Evolutionary Biology, Yale University, New Haven CT 06520 USA; Ladwig, Laura M. [Department of Biology, University of New Mexico, Albuquerque NM 87103 USA; Lambrinos, John G. [Department of Horticulture, Oregon State University, Corvallis OR 97331 USA; Leakey, Andrew D. B. [Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana IL 61801 USA; Li, Qi [Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008 Qinghai China; Li, Wei [Yunnan Academy of Biodiversity, Southwest Forestry University, Kunming 650224 China; McCulley, Rebecca [Department of Plant & Soil Sciences, University of Kentucky, Lexington KY 40546 USA; Melbourne, Brett [Department of Ecology and Evolutionary Biology, University of Colorado, Boulder CO 80309 USA; Mitchell, Charles E. [Department of Biology, University of North Carolina, Chapel Hill NC 27599 USA; Moore, Joslin L. [Australian Research Centre for Urban Ecology, Melbourne, c/o School of Botany, University of Melbourne, Melbourne Victoria 3010 Australia; Morgan, John [Department of Botany, La Trobe University, Bundoora 3086 Victoria Australia; Mortensen, Brent [Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames IA 50011 USA; O' Halloran, Lydia R. [Department of Zoology, Oregon State University, Corvallis OR 97331 USA; Pärtel, Meelis [Institute of Ecology and Earth Sciences, University of Tartu, Tartu Estonia; Pascual, Jesús [Instituto de Investigaciones Marinas y Costeras (UNMdP-CONICET), Mar del Plata Argentina; Pyke, David A. [U.S. Geological Survey Forest and Rangeland Ecosystem Science Center, Corvallis OR 97331 USA; Risch, Anita C. [Swiss Federal Institute for Forest, Snow and Landscape Research, 8903 Birmensdorf Switzerland; Salguero-Gómez, Roberto [ARC Centre of Excellence for Environmental Decisions, School of Biological Sciences, The University of Queensland, Brisbane Queensland 4072 Australia; Sankaran, Mahesh [National Centre for Biological Sciences, GKVK Campus, Bellary Road Bangalore 560065 India; Schuetz, Martin [Swiss Federal Institute for Forest, Snow and Landscape Research, 8903 Birmensdorf Switzerland; Simonsen, Anna [Department of Ecology & Evolutionary Biology, University of Toronto, Toronto ON M5S 3B2 Canada; Smith, Melinda [Department of Biology, Colorado State University, Fort Collins CO 80523 USA; Stevens, Carly [Lancaster Environment Center, Lancaster University, Lancaster LA1 4YQ UK; Sullivan, Lauren [Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames IA 50011 USA; Wardle, Glenda M. [Desert Ecology Research Group, School of Biological Sciences, University of Sydney, Sydney NSW 2006 Australia; Wolkovich, Elizabeth M. [Biodiversity Research Centre, University of British Columbia, Vancouver V6T 1Z4 Canada; Wragg, Peter D. [Department of Ecology, Evolution, and Behavior, University of MN, St. Paul MN 55108 USA; Wright, Justin [Department of Biology, Duke University, Durham NC 27708 USA; Yang, Louie [Department of Entomology, University of California, Davis CA 95616 USA

    2013-10-16

    Invasions have increased the size of regional species pools, but are typically assumed to reduce native diversity. However, global-scale tests of this assumption have been elusive because of the focus on exotic species richness, rather than relative abundance. This is problematic because low invader richness can indicate invasion resistance by the native community or, alternatively, dominance by a single exotic species. Here, we used a globally replicated study to quantify relationships between exotic richness and abundance in grass-dominated ecosystems in 13 countries on six continents, ranging from salt marshes to alpine tundra. We tested effects of human land use, native community diversity, herbivore pressure, and nutrient limitation on exotic plant dominance. Despite its widespread use, exotic richness was a poor proxy for exotic dominance at low exotic richness, because sites that contained few exotic species ranged from relatively pristine (low exotic richness and cover) to almost completely exotic-dominated ones (low exotic richness but high exotic cover). Both exotic cover and richness were predicted by native plant diversity (native grass richness) and land use (distance to cultivation). Although climate was important for predicting both exotic cover and richness, climatic factors predicting cover (precipitation variability) differed from those predicting richness (maximum temperature and mean temperature in the wettest quarter). Herbivory and nutrient limitation did not predict exotic richness or cover. Exotic dominance was greatest in areas with low native grass richness at the site- or regional-scale. Although this could reflect native grass displacement, a lack of biotic resistance is a more likely explanation, given that grasses comprise the most aggressive invaders. These findings underscore the need to move beyond richness as a surrogate for the extent of invasion, because this metric confounds monodominance with invasion resistance. Monitoring

  4. Facilitating the recovery of natural evergreen forests in South Africa via invader plant stands

    Directory of Open Access Journals (Sweden)

    Coert J. Geldenhuys

    2017-11-01

    Full Text Available Contrary to general belief, planted and naturalized stands of introduced species facilitate the recovery of natural evergreen forests and their diversity. Forest rehabilitation actions are often performed at great cost: mature forest species are planted, while species with adaptations to recover effectively and quickly after severe disturbance are ignored; or stands are cleared of invasive alien species before native tree species are planted. By contrast, cost-effective commercial plantation forestry systems generally use fast-growing pioneer tree species introduced from other natural forest regions. Such planted tree stands often facilitate the recovery of shade-tolerant native forest species. This paper provides a brief overview of disturbance-recovery processes at landscape level, and how pioneer stands of both native and introduced tree species develop from monocultures to diverse mature forest communities. It uses one example of a study of how natural forest species from small forest patches of 3 ha in total invaded a 90-ha stand of the invasive Black wattle, Acacia mearnsii, over a distance of 3.1 ha at Swellendam near Cape Town, South Africa. The study recorded 329 forest species clusters across the wattle stand: more large clusters closer to and more smaller clusters further away from natural forest patches. The 28 recorded forest species (of potentially 40 species in the surrounding forest patches included 79% tree and 21% shrub species. Colonizing forest species had mostly larger fleshy fruit and softer small seeds, and were dispersed by mostly birds and primate species. Maturing forest trees within developing clusters in the wattle stand became a source for forest regeneration away from the clusters, showing different expansion patterns. Four sets of fenced-unfenced plots in the wattle stand showed the impact of browsing by livestock, antelope, rodents and insects on the successful establishment of regenerating forest species, and the

  5. Impacts of invasive plants on carbon pools depend on both species' traits and local climate.

    Science.gov (United States)

    Martin, Philip A; Newton, Adrian C; Bullock, James M

    2017-04-01

    Invasive plants can alter ecosystem properties, leading to changes in the ecosystem services on which humans depend. However, generalizing about these effects is difficult because invasive plants represent a wide range of life forms, and invaded ecosystems differ in their plant communities and abiotic conditions. We hypothesize that differences in traits between the invader and native species can be used to predict impacts and so aid generalization. We further hypothesize that environmental conditions at invaded sites modify the effect of trait differences and so combine with traits to predict invasion impacts. To test these hypotheses, we used systematic review to compile data on changes in aboveground and soil carbon pools following non-native plant invasion from studies across the World. Maximum potential height (H max ) of each species was drawn from trait databases and other sources. We used meta-regression to assess which of invasive species' H max , differences in this height trait between native and invasive plants, and climatic water deficit, a measure of water stress, were good predictors of changes in carbon pools following invasion. We found that aboveground biomass in invaded ecosystems relative to uninvaded ones increased as the value of H max of invasive relative to native species increased, but that this effect was reduced in more water stressed ecosystems. Changes in soil carbon pools were also positively correlated with the relative H max of invasive species, but were not altered by water stress. This study is one of the first to show quantitatively that the impact of invasive species on an ecosystem may depend on differences in invasive and native species' traits, rather than solely the traits of invasive species. Our study is also the first to show that the influence of trait differences can be altered by climate. Further developing our understanding of the impacts of invasive species using this framework could help researchers to identify not

  6. Staged invasions across disparate grasslands: Effects of seed provenance, consumers and disturbance on productivity and species richness

    Science.gov (United States)

    John L. Maron; Harald Auge; Dean E. Pearson; Lotte Korell; Isabell Hensen; Katharine N. Suding; Claudia Stein

    2014-01-01

    Exotic plant invasions are thought to alter productivity and species richness, yet these patterns are typically correlative. Few studies have experimentally invaded sites and asked how addition of novel species influences ecosystem function and community structure and examined the role of competitors and/or consumers in mediating these patterns. We invaded disturbed...

  7. Synergistic interactions of CO2 enrichment and nitrogen deposition promote growth and ecophysiological advantages of invading Eupatorium adenophorum in Southwest China.

    Science.gov (United States)

    Lei, Yan-bao; Wang, Wei-bin; Feng, Yu-long; Zheng, Yu-long; Gong, He-de

    2012-10-01

    Global environmental change and ongoing biological invasions are the two prominent ecological issues threatening biodiversity worldwide, and investigations of their interaction will aid to predict plant invasions and inform better management strategies in the future. In this study, invasive Eupatorium adenophorum and native congener E. stoechadosmum were compared at ambient and elevated atmospheric carbon dioxide (CO(2)) concentrations combined with three levels of nitrogen (N; reduced, control and increased) in terms of growth, energy gain, and cost. Compared with E. stoechadosmum, E. adenophorum adopted a quicker-return energy-use strategy, i.e. higher photosynthetic energy-use efficiency and shorter payback time. Lower leaf mass per area may be a pivotal trait for the invader, which contributed to an increased N allocation to Rubisco at the expense of cell walls and therefore to higher photosynthetic energy gain. CO(2) enrichment and N deposition synergistically promoted plant growth and influenced some related ecophysiological traits, and the synergistic effects were greater for the invader than for the native congener. Reducing N availability by applying sugar eliminated the advantages of the invader over its native congener at both CO(2) levels. Our results indicate that CO(2) enrichment and N deposition may exacerbate E. adenophorum's invasion in the future, and manipulating environmental resources such as N availability may be a feasible tool for managing invasion impacts of E. adenophorum.

  8. 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...

  9. Rapid evolution mitigates the ecological consequences of an invasive species (Bythotrephes longimanus) in lakes in Wisconsin.

    Science.gov (United States)

    Gillis, Michael K; Walsh, Matthew R

    2017-07-12

    Invasive species have extensive negative consequences for biodiversity and ecosystem health. Novel species also drive contemporary evolution in many native populations, which could mitigate or amplify their impacts on ecosystems. The predatory zooplankton Bythotrephes longimanus invaded lakes in Wisconsin, USA, in 2009. This invasion caused precipitous declines in zooplankton prey ( Daphnia pulicaria ), with cascading impacts on ecosystem services (water clarity). Here, we tested the link between Bythotrephes invasion, evolution in Daphnia and post-invasion ecological dynamics using 15 years of long-term data in conjunction with comparative experiments. Invasion by Bythotrephes is associated with rapid increases in the body size of Daphnia Laboratory experiments revealed that such shifts have a genetic component; third-generation laboratory-reared Daphnia from 'invaded' lakes are significantly larger and exhibit greater reproductive effort than individuals from 'uninvaded' lakes. This trajectory of evolution should accelerate Daphnia population growth and enhance population persistence. We tested this prediction by comparing analyses of long-term data with laboratory-based simulations, and show that rapid evolution in Daphnia is associated with increased population growth in invaded lakes. © 2017 The Authors.

  10. Persistence of Native Trees in an Invaded Hawaiian Lowland Wet Forest: Experimental Evaluation of Light and Water Constraints

    Science.gov (United States)

    Jodie R. Schulten; T. Colleen Cole; Susan Cordell; Keiko M. Publico; Rebecca Ostertag; Jaime E. Enoka; Jené D. Michaud

    2014-01-01

    Hawaiian lowland wet forests are heavily invaded and their restoration is most likely to be successful if native species selected for restoration have efficient resource-use traits. We evaluated growth, survival, and ecophysiological responses of four native and four invasive species in a greenhouse experiment that simulated reduced light and water conditions commonly...

  11. A contribution to improved radiotherapy for muscle invading urinary bladder cancer

    Energy Technology Data Exchange (ETDEWEB)

    Muren, Ludvig PAul

    2002-07-01

    Cystectomy has traditionally been regarded the treatment of choice for muscle invading urinary bladder cancer in most countries. Radiotherapy has been offered patients considered unfit for cystectomy. Since the contraindications of surgery are frequent among bladder cancer patients, a substantial amount of patients with muscle invading bladder cancer (typically 50%) are still managed primarily with radiation. Recently, a tri-modality, organsparing treatment (trans-urethral resection and radio-chemotherapy) has been proposed for bladder cancer, like in the management of a range of other common malignancies. This approach may provide as high control rates as cystectomy yet maintain a higher quality of life for selected patient groups. In both the radical radiotherapy and the combined modality approach, high radiation doses are needed to improve local disease control. Radiation dose escalation requires improved conformation of dose distributions. This PhD programme aimed to develop improved conformal radiotherapy procedures in the management of patients with muscle invading urinary bladder cancer. In the initial phase of this work, computer-controlled movement of the linear accelerator collimator jaws during beam delivery was applied to shape so-called partially wedged beams (PWBs), that were designed specifically to tailor the dose distribution in bladder irradiation closer to the defined bladder target. The dosimetric verification and treatment planning implementation of this beam delivery concept were addressed, and we documented that these dynamic beams were delivered as accurately as standard beams. Particular attention was given to the BMS-96 diode array system, as it was adapted to dynamic beam dosimetry. Next, the potential clinical impact of these beams was analysed. In a retrospectively study of a set of urinary bladder treatment plans, the PWBs were seen to improve the dose homogeneity inside the bladder target as well as to reduce normal tissue (small

  12. A contribution to improved radiotherapy for muscle invading urinary bladder cancer

    International Nuclear Information System (INIS)

    Muren, Ludvig PAul

    2002-01-01

    Cystectomy has traditionally been regarded the treatment of choice for muscle invading urinary bladder cancer in most countries. Radiotherapy has been offered patients considered unfit for cystectomy. Since the contraindications of surgery are frequent among bladder cancer patients, a substantial amount of patients with muscle invading bladder cancer (typically 50%) are still managed primarily with radiation. Recently, a tri-modality, organsparing treatment (trans-urethral resection and radio-chemotherapy) has been proposed for bladder cancer, like in the management of a range of other common malignancies. This approach may provide as high control rates as cystectomy yet maintain a higher quality of life for selected patient groups. In both the radical radiotherapy and the combined modality approach, high radiation doses are needed to improve local disease control. Radiation dose escalation requires improved conformation of dose distributions. This PhD programme aimed to develop improved conformal radiotherapy procedures in the management of patients with muscle invading urinary bladder cancer. In the initial phase of this work, computer-controlled movement of the linear accelerator collimator jaws during beam delivery was applied to shape so-called partially wedged beams (PWBs), that were designed specifically to tailor the dose distribution in bladder irradiation closer to the defined bladder target. The dosimetric verification and treatment planning implementation of this beam delivery concept were addressed, and we documented that these dynamic beams were delivered as accurately as standard beams. Particular attention was given to the BMS-96 diode array system, as it was adapted to dynamic beam dosimetry. Next, the potential clinical impact of these beams was analysed. In a retrospectively study of a set of urinary bladder treatment plans, the PWBs were seen to improve the dose homogeneity inside the bladder target as well as to reduce normal tissue (small

  13. Do riparian plant community characteristics differ between Tamarix (L.) invaded and non-invaded sites on the upper Verde River, Arizona?

    Science.gov (United States)

    Tyler D. Johnson; Thomas E. Kolb; Alvin L. Medina

    2009-01-01

    Invasion by Tamarix (L.) can severely alter riparian areas of the western U.S., which are globally rare ecosystems. The upper Verde River, Arizona, is a relatively free-flowing river and has abundant native riparian vegetation. Tamarix is present on the upper Verde but is a minor component of the vegetation (8% of stems). This...

  14. Measuring Entrepreneurial Ecosystems

    OpenAIRE

    Stam, F.C.

    2017-01-01

    How can entrepreneurial ecosystems and productive entrepreneurship can be traced empirically and how is entrepreneurship related to entrepreneurial ecosystems. The analyses in this chapter show the value of taking a systems view on the context of entrepreneurship. We measure entrepreneurial ecosystem elements and use these to compose an entrepreneurial ecosystem index. Next, we measure the output of entrepreneurial ecosystems with different indicators of high-growth firms. We use the 12 provi...

  15. Invasive plant species in hardwood tree plantations

    Science.gov (United States)

    Rochelle R. Beasley; Paula M. Pijut

    2010-01-01

    Invasive plants are species that can grow and spread aggressively, mature quickly, and invade an ecosystem causing economic and environmental damage. Invasive plants usually invade disturbed areas, but can also colonize small areas quickly, and may spread and dominate large areas in a few short years. Invasive plant species displace native or desirable forest...

  16. Self-reinforcing impacts of plant invasions change over time.

    Science.gov (United States)

    Yelenik, Stephanie G; D'Antonio, Carla M

    2013-11-28

    Returning native species to habitats degraded by biological invasions is a critical conservation goal. A leading hypothesis poses that exotic plant dominance is self-reinforced by impacts on ecosystem processes, leading to persistent stable states. Invaders have been documented to modify fire regimes, alter soil nutrients or shift microbial communities in ways that feed back to benefit themselves over competitors. However, few studies have followed invasions through time to ask whether ecosystem impacts and feedbacks persist. Here we return to woodland sites in Hawai'i Volcanoes National Park that were invaded by exotic C4 grasses in the 1960s, the ecosystem impacts of which were studied intensively in the 1990s. We show that positive feedbacks between exotic grasses and soil nitrogen cycling have broken down, but rather than facilitating native vegetation, the weakening feedbacks facilitate new exotic species. Data from the 1990s showed that exotic grasses increased nitrogen-mineralization rates by two- to fourfold, but were nitrogen-limited. Thus, the impacts of the invader created a positive feedback early in the invasion. We now show that annual net soil nitrogen mineralization has since dropped to pre-invasion levels. In addition, a seedling outplanting experiment that varied soil nitrogen and grass competition demonstrates that the changing impacts of grasses do not favour native species re-establishment. Instead, decreased nitrogen availability most benefits another aggressive invader, the nitrogen-fixing tree Morella faya. Long-term studies of invasions may reveal that ecosystem impacts and feedbacks shift over time, but that this may not benefit native species recovery.

  17. Mapping Ecosystem Services

    OpenAIRE

    Georgiev,Teodor; Burkhard,Benjamin; Maes,Joachim

    2017-01-01

    Ecosystem services are the contributions of ecosystem structure and function (in combination with other inputs) to human well-being. That means, humankind is strongly dependent on well-functioning ecosystems and natural capital that are the base for a constant flow of ecosystem services from nature to society. Therefore ecosystem services have the potential to become a major tool for policy and decision making on global, national, regional and local scales. Possible applications are manifold:...

  18. Distribució i grau d’invasió de la formiga argentina (Linepithema humile Mayr) (Hymenoptera: Formicidae) al Parc Natural de s’Albufera des Grau, Menorca (Illes Balears)

    OpenAIRE

    Abril, Silvia; Gómez, Crisanto

    2012-01-01

    The Argentine ant is an exotic invasive species present in all the Mediterranean and subtropical ecosystems of the world. It is closely associated to urban and human-disturbed areas, even though it can also invade natural areas causing a strong negative effect in the biodiversity of the invaded area. In Menorca, the fist record of its presence was in 1976. In 2004 it was detected for the first time invading a natural area in the island, the s’Albufera des Grau Natural Park. ...

  19. Linking Native and Invader Traits Explains Native Spider Population Responses to Plant Invasion.

    Directory of Open Access Journals (Sweden)

    Jennifer N Smith

    Full Text Available Theoretically, the functional traits of native species should determine how natives respond to invader-driven changes. To explore this idea, we simulated a large-scale plant invasion using dead spotted knapweed (Centaurea stoebe stems to determine if native spiders' web-building behaviors could explain differences in spider population responses to structural changes arising from C. stoebe invasion. After two years, irregular web-spiders were >30 times more abundant and orb weavers were >23 times more abundant on simulated invasion plots compared to controls. Additionally, irregular web-spiders on simulated invasion plots built webs that were 4.4 times larger and 5.0 times more likely to capture prey, leading to >2-fold increases in recruitment. Orb-weavers showed no differences in web size or prey captures between treatments. Web-spider responses to simulated invasion mimicked patterns following natural invasions, confirming that C. stoebe's architecture is likely the primary attribute driving native spider responses to these invasions. Differences in spider responses were attributable to differences in web construction behaviors relative to historic web substrate constraints. Orb-weavers in this system constructed webs between multiple plants, so they were limited by the overall quantity of native substrates but not by the architecture of individual native plant species. Irregular web-spiders built their webs within individual plants and were greatly constrained by the diminutive architecture of native plant substrates, so they were limited both by quantity and quality of native substrates. Evaluating native species traits in the context of invader-driven change can explain invasion outcomes and help to identify factors limiting native populations.

  20. Ecosystem Jenga!

    Science.gov (United States)

    Umphlett, Natalie; Brosius, Tierney; Laungani, Ramesh; Rousseau, Joe; Leslie-Pelecky, Diandra L.

    2009-01-01

    To give students a tangible model of an ecosystem and have them experience what could happen if a component of that ecosystem were removed; the authors developed a hands-on, inquiry-based activity that visually demonstrates the concept of a delicately balanced ecosystem through a modification of the popular game Jenga. This activity can be…

  1. Alpine ecosystems

    Science.gov (United States)

    P.W. Rundel; C.I. Millar

    2016-01-01

    Alpine ecosystems are typically defined as those areas occurring above treeline, while recognizing that alpine ecosystems at a local scale may be found below this boundary for reasons including geology, geomorphology, and microclimate. The lower limit of the alpine ecosystems, the climatic treeline, varies with latitude across California, ranging from about 3500 m in...

  2. Methods for converting continuous shrubland ecosystem component values to thematic National Land Cover Database classes

    Science.gov (United States)

    Rigge, Matthew B.; Gass, Leila; Homer, Collin G.; Xian, George Z.

    2017-10-26

    The National Land Cover Database (NLCD) provides thematic land cover and land cover change data at 30-meter spatial resolution for the United States. Although the NLCD is considered to be the leading thematic land cover/land use product and overall classification accuracy across the NLCD is high, performance and consistency in the vast shrub and grasslands of the Western United States is lower than desired. To address these issues and fulfill the needs of stakeholders requiring more accurate rangeland data, the USGS has developed a method to quantify these areas in terms of the continuous cover of several cover components. These components include the cover of shrub, sagebrush (Artemisia spp), big sagebrush (Artemisia tridentata spp.), herbaceous, annual herbaceous, litter, and bare ground, and shrub and sagebrush height. To produce maps of component cover, we collected field data that were then associated with spectral values in WorldView-2 and Landsat imagery using regression tree models. The current report outlines the procedures and results of converting these continuous cover components to three thematic NLCD classes: barren, shrubland, and grassland. To accomplish this, we developed a series of indices and conditional models using continuous cover of shrub, bare ground, herbaceous, and litter as inputs. The continuous cover data are currently available for two large regions in the Western United States. Accuracy of the “cross-walked” product was assessed relative to that of NLCD 2011 at independent validation points (n=787) across these two regions. Overall thematic accuracy of the “cross-walked” product was 0.70, compared to 0.63 for NLCD 2011. The kappa value was considerably higher for the “cross-walked” product at 0.41 compared to 0.28 for NLCD 2011. Accuracy was also evaluated relative to the values of training points (n=75,000) used in the development of the continuous cover components. Again, the “cross-walked” product outperformed NLCD

  3. Do species differ in their ability to coexist with the dominant alien Lupinus polyphyllus? A comparison between two distinct invaded ranges and a native range

    Directory of Open Access Journals (Sweden)

    Martin Hejda

    2013-06-01

    Full Text Available The community-level impacts of invasive plants are likely to vary depending on the character of native species of the target communities and their ability to thrive within the stands of the dominant alien invader. Therefore, I examined the response of native species richness to the cover of the dominant alien Lupinus polyphyllus in two distinct invaded ranges: Czech Republic (Central Europe and New Zealand. I compared the relation between native species richness and the cover of the dominant alien L. polyphyllus with that in its native range, Pacific Northwest, USA.In the native range, I found no response of native species richness to the cover of L. polyphyllus. In the Czech Republic (central Europe, the richness of native species related to it negativelly, but the relation was only marginally significant. Contrary to that, the richness of species native to New Zealand related to the cover of L. polyphyllus strongly negatively and the negative relation was significantly stronger than that of species native to Europe.Of the two invaded ranges, species native to New Zealand have been documented to be much more vulnerable to the conditions associated with the invasion and dominance of L. polyphyllus, compared to species native to central Europe. This principle has been shown both across these two invaded ranges and in New Zealand, where the aliens of european origin successfully coexist with the dominant invasive alien L. polyphyllus. Similarly, species in the native range of L. polyphyllus showed no relation to its cover, indicating their ability to thrive even in dense stands of this dominant species.

  4. Preoperative radiation therapy for muscle-invading bladder carcinoma

    International Nuclear Information System (INIS)

    Cox, J.A.; Greven, K.M.; Anscher, M.S.; Morgan, T.M.; Scott, J.

    1991-01-01

    This paper reports on low-dose and high-dose radiation therapy (RT) followed by cystectomy for bladder carcinoma that was evaluated for survival, failure patterns, and complications as these outcomes have been incompletely documented in the past. One hundred five patients with clinical stages T2-T4 (muscle-invading) transitional cell carcinoma of the bladder who completed preoperative RT followed by total cystectomy were evaluated. Eighty-five patients received 20-27 Gy in 4-7 fractions (group A). Twenty patients received 40-50 Gy in 20-28 fractions (group B). Actuarial 5-year survival was 45% and 29% (P = .06) for groups A and B, respectively; 6% of group A was stage T4 compared with 30% of group B. Five-year actuarial survival for patients with stages T2-T3 in groups A and B was 46% and 42%, respectively, while that for T4 was 33% and 0% in groups A and B, respectively. Multivariate analysis revealed that stage, grade, and presence of hydronephrosis independently affected survival. Five-year actuarial local control rates for T2, T3, and T4 were 93%, 93%, and 22%, respectively, with no significant difference between RT groups. Rates of distant metastasis and complications versus preoperative regime and stage were similar

  5. Rapid ecosystem shifts in peatlands: linking plant physiology and succession.

    Science.gov (United States)

    Granath, Gustaf; Strengbom, Joachim; Rydin, Håkan

    2010-10-01

    Stratigraphic records from peatlands suggest that the shift from a rich fen (calcareous fen) to an ombrotrophic bog can occur rapidly. This shift constitutes a switch from a species-rich ecosystem to a species-poor one with greater carbon storage. In this process, the invasion and expansion of acidifying bog species of Sphagnum (peat mosses) play a key role. To test under what conditions an acidifying bog species could invade a rich fen, we conducted three experiments, contrasting the bog species S. fucsum with the rich-fen species S. warnstorfii and S. teres. We first tested the effect of calcareous water by growing the three species at different constant height above the water table (HWT; 2, 7, and 14 cm) in a rich-fen pool and measured maximum photosynthetic rate and production and difference in length growth as an indicator of competition. In none of the species was the photosynthetic capacity negatively affected when placed at low HWT, but S. fuscum was a weaker competitor at low HWT. In our second experiment we transplanted the three species into microhabitats with different and naturally varying HWT in a rich fen. Here, S. fuscum nearly ceased to photosynthesize when transplanted to low HWT (brown moss carpet), while it performed similarly to the two rich-fen species at the intermediate level (S. warnstorfii hummock level). In contrast to S. fuscum, the rich-fen sphagna performed equally well in both habitats. The brown moss carpet was seasonally flooded, and in our third experiment we found that S. fuscum, but not S. teres, was severely damaged when submerged in rich-fen water. Our results suggest two thresholds in HWT affecting the ecosystem switch: one level that reduces the risk of submergence and a higher one that makes bog sphagna competitive against the rich-fen species.

  6. Strategic ecosystems of Colombia

    International Nuclear Information System (INIS)

    Marquez Calle German

    2002-01-01

    The author relates the ecosystems in Colombia, he makes a relationship between ecosystems and population, utility of the ecosystems, transformation of the ecosystems and poverty and he shows a methodology of identification of strategic ecosystems

  7. Introduction: Exotic annual Bromus in the western USA [Chapter 1

    Science.gov (United States)

    Matthew J. Germino; Jeanne C. Chambers; Cynthia S. Brown

    2016-01-01

    The spread and impacts of exotic species are unambiguous, global threats to many ecosystems. A prominent example is the suite of annual grasses in the Bromus genus (Bromus hereafter) that originate from Europe and Eurasia but have invaded or are invading large areas of the Western USA. This book brings a diverse, multidisciplinary group of authors together to...

  8. Transformation of Digital Ecosystems

    DEFF Research Database (Denmark)

    Henningsson, Stefan; Hedman, Jonas

    2014-01-01

    the Digital Ecosystem Technology Transformation (DETT) framework for explaining technology-based transformation of digital ecosystems by integrating theories of business and technology ecosystems. The framework depicts ecosystem transformation as distributed and emergent from micro-, meso-, and macro- level......In digital ecosystems, the fusion relation between business and technology means that the decision of technical compatibility of the offering is also the decision of how to position the firm relative to the coopetive relations that characterize business ecosystems. In this article we develop...... coopetition. The DETT framework consists an alternative to the existing explanations of digital ecosystem transformation as the rational management of one central actor balancing ecosystem tensions. We illustrate the use of the framework by a case study of transformation in the digital payment ecosystem...

  9. Multi-year net ecosystem carbon balance at a horticulture-extracted restored peatland

    Science.gov (United States)

    Nugent, Kelly; Strachan, Ian; Strack, Maria

    2017-04-01

    Restoration of previously extracted peatlands is essential to minimize the impact of drainage and peat removal. Best practices restoration methods have been developed that include ditch blocking, site leveling and reintroducing bog vegetation using the moss layer transfer technique. A long term goal of restoration is the return to a peat accumulating ecosystem. Bois-des-Bel is a cool-temperate bog, located in eastern Quebec, Canada, that was vacuum harvested until 1980 and restored in 1999. While several studies have used discrete (chamber) methods to determine the net carbon exchange from rewetted or restored peatlands, ours appears to be the first to have multiple complete years of net ecosystem carbon exchange from a restored northern peatland. An eddy covariance flux tower instrumented with a sonic anemometer and open-path CO2/H2O and CH4 analyzers was operated continuously over three years to produce a robust estimate of net carbon sequestration. Our initial results indicate that this restored peatland was a consistent moderate annual net sink for CO2, a moderate source of CH4 and had low losses of dissolved organic carbon compared to undisturbed northern latitude peatlands. Closed chambers combined with a fast response CO2/H2O/CH4 analyzer were used to investigate ecohydrological controls on net ecosystem exchange of CO2 (NEE) and CH4 flux from the restored fields and remnant ditches at the site. CH4 release was found to be an order of magnitude higher in the ditches compared to the fields, with non-vegetated ditch showing a greater range in flux compared to areas invaded by Typha latifolia. Bubble magnitude and count were highest in the non-vegetated ditch, followed by Typha plots and were undetectable in the restored fields. The latter may be partially attributed to the high cover of Eriophorum vaginatum in the restored fields, plants that have aerenchymous tissue, as well as a much deeper water table level. While the non-vegetated ditch areas were a steady

  10. Diffuse infiltrating retinoblastoma invading subarachnoid space

    Directory of Open Access Journals (Sweden)

    Kase S

    2011-06-01

    Full Text Available Satoru Kase1, Kazuhiko Yoshida1, Shigenobu Suzuki2, Koh-ichi Ohshima3, Shigeaki Ohno4, Susumu Ishida11Department of Ophthalmology, Hokkaido University Graduate School of Medicine, Sapporo; 2Department of Ophthalmic Oncology, National Cancer Center Hospital, Tokyo; 3Section of Ophthalmology, Okayama Medical Center, Okayama; 4Department of Ocular Inflammation and Immunology, Hokkaido University Graduate School of Medicine, Sapporo, JapanAbstract: We report herein an unusual case of diffuse infiltrating retinoblastoma involving the brain, which caused a patient’s death 27 months after enucleation. An eight-year-old boy complained of blurred vision in his right eye (OD in October 2006. Funduscopic examination showed optic disc swelling, dense whitish vitreous opacity, and an orange-colored subretinal elevated lesion adjacent to the optic disc. Fluorescein angiography revealed hyperfluorescence in the peripapillary region at an early-phase OD. Because the size of the subretinal lesion and vitreous opacity gradually increased, he was referred to us. His visual acuity was 20/1000 OD on June 20, 2007. Slit-lamp biomicroscopy showed a dense anterior vitreous opacity. Ophthalmoscopically, the subretinal orange-colored area spread out until reaching the mid peripheral region. A B-mode sonogram and computed tomography showed a thick homogeneous lesion without calcification. Gadolinium-enhanced magnetic resonance imaging showed a markedly enhanced appearance of the underlying posterior retina. Enucleation of the right eye was performed nine months after the initial presentation. Histopathology demonstrated retinal detachment and a huge choroidal mass invading the optic nerve head. The tumor was consistent with diffuse infiltrating retinoblastoma. The patient died due to brain involvement 27 months after enucleation. Ophthalmologists should be aware that diffuse infiltrating retinoblastoma may show an unfavorable course if its diagnosis is delayed

  11. Magnetic Resonance Imaging of a Liver Hydatid Cyst Invading the Portal Vein and Causing Portal Cavernomatosis.

    Science.gov (United States)

    Herek, Duygu; Sungurtekin, Ugur

    2015-01-01

    Hepatic hydatid cysts rarely invade portal veins causing portal cavernomatosis as a secondary complication. We report the case of a patient with direct invasion of the right portal vein by hydatid cysts causing portal cavernomatosis diagnosed via magnetic resonance imaging (MRI). The presented case highlights the useful application of MRI with T2-weighted images and gadolinium-enhanced T1-weighted images in the diagnosis of hepatic hydatid lesions presenting with a rare complication of portal cavernomatosis.

  12. The role of adjuvant external beam radiation therapy for papillary thyroid carcinoma invading the trachea

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Suk; Choi, Jae Hyuck; Kim, Kwang Sik [Jeju National University Hospital, Jeju National University School of Medicine, Jeju (Korea, Republic of); and others

    2017-06-15

    To evaluate the effect of adjuvant external beam radiation therapy (EBRT) on local failure-free survival rate (LFFS) for papillary thyroid cancer (PTC) invading the trachea. Fifty-six patients with locally advanced PTC invading the trachea were treated with surgical resection. After surgery, 21 patients received adjuvant EBRT and radioactive iodine therapy (EBRT group) and 35 patients were treated with radioactive iodine therapy (control group). The age range was 26–87 years (median, 56 years). The median follow-up period was 43 months (range, 4 to 145 months). EBRT doses ranged from 50.4 to 66 Gy (median, 60 Gy). Esophagus invasion and gross residual disease was more frequent in the EBRT group. In the control group, local recurrence developed in 9 (9/35, 26%) and new distant metastasis in 2 (2/35, 6%) patients, occurring 4 to 68 months (median, 37 months) and 53 to 68 months (median, 60 months) after surgery, respectively. Two patients had simultaneous local recurrence and new distant metastasis. There was one local failure in the EBRT group at 18 months after surgery (1/21, 5%). The 5-year LFFS was 95% in the EBRT group and 63% in the control group (p = 0.103). In the EBRT group, one late grade 2 xerostomia was developed. Although, EBRT group had a higher incidence of esophagus invasion and gross residual disease, EBRT group showed a better 5-year LFFS. Adjuvant EBRT may have contributed to the better LFFS in these patients.

  13. Fishing for ecosystem services.

    Science.gov (United States)

    Pope, Kevin L; Pegg, Mark A; Cole, Nicholas W; Siddons, Stephen F; Fedele, Alexis D; Harmon, Brian S; Ruskamp, Ryan L; Turner, Dylan R; Uerling, Caleb C

    2016-12-01

    Ecosystems are commonly exploited and manipulated to maximize certain human benefits. Such changes can degrade systems, leading to cascading negative effects that may be initially undetected, yet ultimately result in a reduction, or complete loss, of certain valuable ecosystem services. Ecosystem-based management is intended to maintain ecosystem quality and minimize the risk of irreversible change to natural assemblages of species and to ecosystem processes while obtaining and maintaining long-term socioeconomic benefits. We discuss policy decisions in fishery management related to commonly manipulated environments with a focus on influences to ecosystem services. By focusing on broader scales, managing for ecosystem services, and taking a more proactive approach, we expect sustainable, quality fisheries that are resilient to future disturbances. To that end, we contend that: (1) management always involves tradeoffs; (2) explicit management of fisheries for ecosystem services could facilitate a transition from reactive to proactive management; and (3) adaptive co-management is a process that could enhance management for ecosystem services. We propose adaptive co-management with an ecosystem service framework where actions are implemented within ecosystem boundaries, rather than political boundaries, through strong interjurisdictional relationships. Published by Elsevier Ltd.

  14. Ecosystem degradation in India

    International Nuclear Information System (INIS)

    Sinha, B.N.

    1990-01-01

    Environmental and ecosystem studies have assumed greater relevance in the last decade of the twentieth century than even before. The urban settlements are becoming over-crowded and industries are increasingly polluting the air, water and sound in our larger metropolises. Degradation of different types of ecosystem are discussed in this book, Ecosystem Degradation in India. The book has been divided into seven chapters: Introduction, Coastal and Delta Ecosystem, River Basin Ecosystem, Mountain Ecosystem, Forest Ecosystem, Urban Ecosystem and the last chapter deals with the Environmental Problems and Planning. In the introduction the environmental and ecosystem degradation problems in India is highlighted as a whole while in other chapters mostly case studies by experts who know their respective terrain very intimately are included. The case study papers cover most part of India and deal with local problems, stretching from east coast to west coast and from Kashmir to Kanyakumari. (author)

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Linking ecosystem characteristics to final ecosystem services for public policy

    Science.gov (United States)

    Wong, Christina P; Jiang, Bo; Kinzig, Ann P; Lee, Kai N; Ouyang, Zhiyun

    2015-01-01

    Governments worldwide are recognising ecosystem services as an approach to address sustainability challenges. Decision-makers need credible and legitimate measurements of ecosystem services to evaluate decisions for trade-offs to make wise choices. Managers lack these measurements because of a data gap linking ecosystem characteristics to final ecosystem services. The dominant method to address the data gap is benefit transfer using ecological data from one location to estimate ecosystem services at other locations with similar land cover. However, benefit transfer is only valid once the data gap is adequately resolved. Disciplinary frames separating ecology from economics and policy have resulted in confusion on concepts and methods preventing progress on the data gap. In this study, we present a 10-step approach to unify concepts, methods and data from the disparate disciplines to offer guidance on overcoming the data gap. We suggest: (1) estimate ecosystem characteristics using biophysical models, (2) identify final ecosystem services using endpoints and (3) connect them using ecological production functions to quantify biophysical trade-offs. The guidance is strategic for public policy because analysts need to be: (1) realistic when setting priorities, (2) attentive to timelines to acquire relevant data, given resources and (3) responsive to the needs of decision-makers. PMID:25394857

  17. Invasive, naturalized and casual alien plants in southern Africa: a sum­mary based on the Southern African Plant Invaders Atlas (SAPIA

    Directory of Open Access Journals (Sweden)

    L. Henderson

    2007-08-01

    Full Text Available The primary objective of this publication is to provide an overview of the species identity, invasion status, geographical extent, and abundance of alien plants in South Africa, Swaziland and Lesotho, based on field records from 1979 to the end of 2000. The dataset is all the species records for the study area in the Southern African Plant Invaders Atlas (SAPIA database during this time period. A total of 548 naturalized and casual alien plant species were catalogued and invasion was recorded almost throughout the study area. Most invasion, in terms of both species numbers and total species abundance, was recorded along the southern, southwestern and eastern coastal belts and in the adjacent interior. This area includes the whole of the Fynbos and Forest Biomes, and the moister eastern parts of the Grassland and Savanna Biomes. This study reinforces previous studies that the Fynbos Biome is the most extensively invaded vegetation type in South Africa but it also shows that parts of Savanna and Grassland are as heavily invaded as parts of the Fynbos. The Fabaceae is prominent in all biomes and Acacia with 17 listed species, accounts for a very large proportion of all invasion. Acacia mearmii was by far the most prominent invasive species in the study area, followed by A. saligna, Lantana camara, A. cyclops, Opuntia ficus-indica. Solarium mauritianum, Populus alba/xcanescens, Melia azedarach, A. dealbata and species of Prosopis.

  18. Non-native and native organisms moving into high elevation and high latitude ecosystems in an era of climate change: new challenges for ecology and conservation

    Science.gov (United States)

    Pauchard, Aníbal; Albihn, Ann; Alexander, Jake; Burgess, Treena; Daehler, Curt; Essl, Franz; Evengard, Birgitta; Greenwood, Greg; Haider, Sylvia; Lenoir, Jonathan; McDougall, K.; Milbau, Ann; Muths, Erin L.; Nunez, Martin; Pellissier, Lois; Rabitsch, Wolfgang; Rew, Lisa; Robertson, Mark; Sanders, Nathan; Kueffer, Christoph

    2016-01-01

    Cold environments at high elevation and high latitude are often viewed as resistant to biological invasions. However, climate warming, land use change and associated increased connectivity all increase the risk of biological invasions in these environments. Here we present a summary of the key discussions of the workshop ‘Biosecurity in Mountains and Northern Ecosystems: Current Status and Future Challenges’ (Flen, Sweden, 1–3 June 2015). The aims of the workshop were to (1) increase awareness about the growing importance of species expansion—both non-native and native—at high elevation and high latitude with climate change, (2) review existing knowledge about invasion risks in these areas, and (3) encourage more research on how species will move and interact in cold environments, the consequences for biodiversity, and animal and human health and wellbeing. The diversity of potential and actual invaders reported at the workshop and the likely interactions between them create major challenges for managers of cold environments. However, since these cold environments have experienced fewer invasions when compared with many warmer, more populated environments, prevention has a real chance of success, especially if it is coupled with prioritisation schemes for targeting invaders likely to have greatest impact. Communication and co-operation between cold environment regions will facilitate rapid response, and maximise the use of limited research and management resources.

  19. Towards ecosystem accounting

    NARCIS (Netherlands)

    Duku, C.; Rathjens, H.; Zwart, S.J.; Hein, L.

    2015-01-01

    Ecosystem accounting is an emerging field that aims to provide a consistent approach to analysing environment-economy interactions. One of the specific features of ecosystem accounting is the distinction between the capacity and the flow of ecosystem services. Ecohydrological modelling to support

  20. The Ecosystem of Startups as a Component of the Innovation Ecosystem

    Directory of Open Access Journals (Sweden)

    Sytnik Natalia I.

    2017-08-01

    Full Text Available The article analyzes the current theoretical perceptions of the ecosystem of startups and presents the author’s own vision of this entity. It has been proposed to consider the ecosystem of startups as a subsystem of the innovation ecosystem, which aims at creating innovative products and services by startup companies. The ecosystem of startups is an open dynamic system in which the backbone subject is a startup company at various stages of the life cycle. The sustenance subjects in an ecosystem are the organizations, associations and individuals that cause impacts, to varying degrees, on the establishing or development of startups. The activities of the subjects are carried out in the following directions: public regulation, financing, training, information, and infrastructure support for startups. The ecosystem consists of a number of economic, material-and-technical, market, and socio-cultural factors that directly or indirectly influence the actions of the subjects. The vital activity of the ecosystem of startups is maintained by the active interaction of the subjects, connected by a network of internal links with the environment and between themselves.

  1. Elucidating mechanical transition effects of invading cancer cells with a subnucleus-scaled microfluidic serial dimensional modulation device†

    OpenAIRE

    Mak, Michael; Reinhart-King, Cynthia A.; Erickson, David

    2013-01-01

    Mechanical boundaries that define and regulate biological processes, such as cell-cell junctions and dense extracellular matrix networks, exist throughout the physiological landscape. During metastasis, cancer cells are able to invade across these barriers and spread to distant tissues. While transgressing boundaries is a necessary step for distal colonies to form, little is known about interface effects on cell behavior during invasion. Here we introduce a device and metric to assess cell tr...

  2. Complex effects of ecosystem engineer loss on benthic ecosystem response to detrital macroalgae

    NARCIS (Netherlands)

    Rossi, F.; Gribsholt, B.; Gazeau, F.; Di Santo, V.; Middelburg, J.J.

    2013-01-01

    Ecosystem engineers change abiotic conditions, community assembly and ecosystem functioning. Consequently, their loss may modify thresholds of ecosystem response to disturbance and undermine ecosystem stability. This study investigates how loss of the bioturbating lugworm Arenicola marina modifies

  3. Complex Effects of Ecosystem Engineer Loss on Benthic Ecosystem Response to Detrital Macroalgae

    NARCIS (Netherlands)

    Rossi, F.; Gribsholt, B.; Gazeau, F.; Di Santo, V.; Middelburg, J.J.

    2013-01-01

    Ecosystem engineers change abiotic conditions, community assembly and ecosystem functioning. Consequently, their loss may modify thresholds of ecosystem response to disturbance and undermine ecosystem stability. This study investigates how loss of the bioturbating lugworm Arenicola marina modifies

  4. Linking ecosystem characteristics to final ecosystem services for public policy.

    Science.gov (United States)

    Wong, Christina P; Jiang, Bo; Kinzig, Ann P; Lee, Kai N; Ouyang, Zhiyun

    2015-01-01

    Governments worldwide are recognising ecosystem services as an approach to address sustainability challenges. Decision-makers need credible and legitimate measurements of ecosystem services to evaluate decisions for trade-offs to make wise choices. Managers lack these measurements because of a data gap linking ecosystem characteristics to final ecosystem services. The dominant method to address the data gap is benefit transfer using ecological data from one location to estimate ecosystem services at other locations with similar land cover. However, benefit transfer is only valid once the data gap is adequately resolved. Disciplinary frames separating ecology from economics and policy have resulted in confusion on concepts and methods preventing progress on the data gap. In this study, we present a 10-step approach to unify concepts, methods and data from the disparate disciplines to offer guidance on overcoming the data gap. We suggest: (1) estimate ecosystem characteristics using biophysical models, (2) identify final ecosystem services using endpoints and (3) connect them using ecological production functions to quantify biophysical trade-offs. The guidance is strategic for public policy because analysts need to be: (1) realistic when setting priorities, (2) attentive to timelines to acquire relevant data, given resources and (3) responsive to the needs of decision-makers. © 2014 The Authors. Ecology Letters published by John Wiley & Sons Ltd and CNRS.

  5. Contribution to the alien flora of Montenegro and Supplementum to the Preliminary list of plant invaders

    OpenAIRE

    Stešević, D.; Caković, D.

    2013-01-01

    This contribution is based on the field observations from 2011 to 2013. Besides new data about distribution of some known plant invaders, one new alien species for the flora of Montenegro is reported- Solidago gigantea. This plant was recorded in 2011, on two distinct localities near the road side in peri-urban area of Nikšić and Mojkovac, in the vicinity of gardens, were it has been grown as ornamental. In 2012 survey, species was again reported for Mojkovac, but it disappeared f...

  6. Ecosystem service valuations of mangrove ecosystems to inform decision making and future valuation exercises.

    Directory of Open Access Journals (Sweden)

    Nibedita Mukherjee

    Full Text Available The valuation of ecosystem services is a complex process as it includes several dimensions (ecological, socio-cultural and economic and not all of these can be quantified in monetary units. The aim of this paper is to conduct an ecosystem services valuation study for mangroves ecosystems, the results of which can be used to inform governance and management of mangroves. We used an expert-based participatory approach (the Delphi technique to identify, categorize and rank the various ecosystem services provided by mangrove ecosystems at a global scale. Subsequently we looked for evidence in the existing ecosystem services literature for monetary valuations of these ecosystem service categories throughout the biogeographic distribution of mangroves. We then compared the relative ranking of ecosystem service categories between the monetary valuations and the expert based analysis. The experts identified 16 ecosystem service categories, six of which are not adequately represented in the literature. There was no significant correlation between the expert based valuation (the Delphi technique and the economic valuation, indicating that the scope of valuation of ecosystem services needs to be broadened. Acknowledging this diversity in different valuation approaches, and developing methodological frameworks that foster the pluralism of values in ecosystem services research, are crucial for maintaining the credibility of ecosystem services valuation. To conclude, we use the findings of our dual approach to valuation to make recommendations on how to assess and manage the ecosystem services provided by mangrove ecosystems.

  7. Ecosystem service valuations of mangrove ecosystems to inform decision making and future valuation exercises.

    Science.gov (United States)

    Mukherjee, Nibedita; Sutherland, William J; Dicks, Lynn; Hugé, Jean; Koedam, Nico; Dahdouh-Guebas, Farid

    2014-01-01

    The valuation of ecosystem services is a complex process as it includes several dimensions (ecological, socio-cultural and economic) and not all of these can be quantified in monetary units. The aim of this paper is to conduct an ecosystem services valuation study for mangroves ecosystems, the results of which can be used to inform governance and management of mangroves. We used an expert-based participatory approach (the Delphi technique) to identify, categorize and rank the various ecosystem services provided by mangrove ecosystems at a global scale. Subsequently we looked for evidence in the existing ecosystem services literature for monetary valuations of these ecosystem service categories throughout the biogeographic distribution of mangroves. We then compared the relative ranking of ecosystem service categories between the monetary valuations and the expert based analysis. The experts identified 16 ecosystem service categories, six of which are not adequately represented in the literature. There was no significant correlation between the expert based valuation (the Delphi technique) and the economic valuation, indicating that the scope of valuation of ecosystem services needs to be broadened. Acknowledging this diversity in different valuation approaches, and developing methodological frameworks that foster the pluralism of values in ecosystem services research, are crucial for maintaining the credibility of ecosystem services valuation. To conclude, we use the findings of our dual approach to valuation to make recommendations on how to assess and manage the ecosystem services provided by mangrove ecosystems.

  8. Analysis and design of software ecosystem architectures – Towards the 4S telemedicine ecosystem

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Hansen, Klaus Marius; Kyng, Morten

    2014-01-01

    performed a descriptive, revelatory case study of the Danish telemedicine ecosystem and for ii), we experimentally designed, implemented, and evaluated the architecture of 4S. Results We contribute in three areas. First, we define the software ecosystem architecture concept that captures organization......, and application stove-pipes that inhibit the adoption of telemedical solutions. To which extent can a software ecosystem approach to telemedicine alleviate this? Objective In this article, we define the concept of software ecosystem architecture as the structure(s) of a software ecosystem comprising elements...... experience in creating and evolving the 4S telemedicine ecosystem. Conclusion The concept of software ecosystem architecture can be used analytically and constructively in respectively the analysis and design of software ecosystems....

  9. [Urban ecosystem services: A review].

    Science.gov (United States)

    Mao, Qi-zheng; Huang, Gan-lin; Wu, Jian-guo

    2015-04-01

    Maintaining and improving ecosystem services in urban areas and human well-being are essential for sustainable development and therefore constitute an important topic in urban ecology. Here we reviewed studies on ecosystem services in urban areas. Based on the concept and classification of urban ecosystem services, we summarized characteristics of urban ecosystem services, including the human domination, high demand of ecosystem services in urban areas, spatial heterogeneity and temporal dynamics of ecosystem services supply and demand in urban areas, multi-services of urban green infrastructures, the socio-economic dimension of ecosystem services supply and ecosystem disservices in urban areas. Among different urban ecosystem services, the regulating service and cultural service are particularly indispensable to benefit human health. We pointed out that tradeoffs among different types of ecosystem services mostly occur between supportive service and cultural service, as well as regulating service and cultural service. In particular, we emphasized the relationship between landscape design (i.e. green infrastructure) and ecosystem services supply. Finally, we discussed current gaps to link urban ecosystem services studies to landscape design and management and pointed out several directions for future research in urban ecosystem services.

  10. Temporal scales, ecosystem dynamics, stakeholders and the valuation of ecosystems services

    NARCIS (Netherlands)

    Hein, Lars; Koppen, van C.S.A.K.; Ierland, van Ekko C.; Leidekker, Jakob

    2016-01-01

    Temporal dimensions are highly relevant to the analysis of ecosystem services and their economic value. In this paper, we provide a framework that can be used for analyzing temporal dimensions of ecosystem services, we present a case study including an analysis of the supply of three ecosystem

  11. Impacts of an invasive plant are fundamentally altered by a co-occurring forest disturbance.

    Science.gov (United States)

    Sokol, Noah W; Kuebbing, Sara E; Bradford, Mark A

    2017-08-01

    Invasive species frequently co-occur with other disturbances, which can impact the same ecosystem functions as the invader. Yet invasion studies rarely control for the presence of these other disturbances, although their overlapping effects may influence the direction and magnitude of impacts attributed to the invader alone. Here, we ask whether controlling for the presence of a co-occurring disturbance, as well as the time since disturbance, yields different values of an invader's ecosystem effects than when these factors remain unaddressed. We used a chronosequence of six forest stands at a single site: five logged stands that each contained paired invaded-uninvaded plots of the forest understory invasive grass Microstegium vimineum, as well as one unlogged and uninvaded control stand. By controlling for the presence of both logging and invasion, we untangled the effects of each through time. We found that the co-occurring disturbance of logging can dramatically alter the measured effects of M. vimineum by amplifying, dampening, negating, or entirely reversing the direction of the invader's impacts. During its period of peak impact, logging amplified the invader's positive effect on the size of the soil microbial biomass pool by 24%, reduced the invader's positive effect on soil water holding capacity by 5%, negated the invader's positive effect on the particulate organic matter carbon pool (from a 9% increase to no significant effect), and reversed the direction of the invader's impact on net nitrogen mineralization rate from a 51% increase to a 52% decrease. Furthermore, the influence of logging on the invader's impacts was not static, but dynamic through time. The results from our site therefore demonstrate that failure to account for the impacts of a co-occurring disturbance, as well as the time since disturbance, can result in flawed inference about the nature of an invader's effects. Future research should determine how widespread such flawed inference

  12. Middle-preserving pancreatectomy for advanced transverse colon cancer invading the duodenun and non-functioning endocrine tumor in the pancreatic tail.

    Science.gov (United States)

    Noda, Hiroshi; Kato, Takaharu; Kamiyama, Hidenori; Toyama, Nobuyuki; Konishi, Fumio

    2011-02-01

    A 73-year-old female was referred to our hospital with a diagnosis of advanced transverse colon cancer with severe anemia and body weight loss. Preoperative evaluations, including colonoscopy, gastroduodenoscopy, and computed tomography, revealed not only a transverse colon cancer massively invading the duodenum, but also a non-functioning endocrine tumor in the pancreatic tail. We performed middle-preserving pancreatectomy (MPP) with right hemicolectomy for these tumors with a curative intent. After the resection, about 6 cm of the body of the pancreas was preserved, and signs of diabetes mellitus have not appeared. The postoperative course was complicated by a grade B pancreatic fistula, but this was successfully treated with conservative management. After a 33-day hospital stay, the patient returned to daily life without signs of pancreatic exocrine insufficiency. Although the long-term follow-up of the patient is indispensable, in this case, MPP might be able to lead to the curative resection of transverse colon cancer massively invading the duodenum and non-functioning endocrine tumor in the pancreatic tail with preservation of pancreatic function.

  13. Honey locust (Gleditsia triacanthos l. (Fabaceae)) invasion effect on temperature, light and metabolism of a Pampean Stream

    International Nuclear Information System (INIS)

    Giorgi, Adonis David; Vilches, Carolina; Rodriguez Castro, Maria Carolina; Zunino, Eduardo; Debandi, Juan; Kravetz, Sebastian; Torremorell, Ana

    2014-01-01

    The establishment of invader species in a region generally modifies the ecosystems where they are introduced. In this study we analyze the effect produced by a gleditsia triacanthos (Honey locust) invasion on a Pampean Stream. This organism modifies the temperature and the light reaching the stream. Thermal range shows significant differences between reaches but mean tem between 85 and 95 % down the trees. These modifications reduce the primary gross production of 2.7 to 1.7 g 02. M"2 at spring and of 25 to 20 g 02. M"2 at summer. Respiration in spring and summer is halved at invaded reaches, but net ecosystem metabolism is similar in both reach and seasons. Moreover, the reach invaded by honey locust show scarce macrophytes. We argue that the honey locust reduces the diversity by reduction of macrophytes and their associated organisms but also reduce the primary production causing changes in the food web

  14. Spatial Pattern and Scale Influence Invader Demographic Response to Simulated Precipitation Change in an Annual Grassland Community.

    Directory of Open Access Journals (Sweden)

    Meghan J Skaer Thomason

    Full Text Available It is important to predict which invasive species will benefit from future changes in climate, and thereby identify those invaders that need particular attention and prioritization of management efforts. Because establishment, persistence, and spread determine invasion success, this prediction requires detailed demographic information. Explicit study of the impact of pattern on demographic response is particularly important for species that are naturally patchy, such as the invasive grass, Aegilops triuncialis. In the northern California Coast Range, where climate change may increase or decrease mean annual rainfall, we conducted a field experiment to understand the interaction of climate change and local-scale patterning on the demography of A. triuncialis. We manipulated precipitation (reduced, ambient, or augmented, seed density, and seeding pattern. Demographic and environmental data were collected for three years following initial seeding. Pattern and scale figure prominently in the demographic response of A. triuncialis to precipitation manipulation. Pattern interacts with precipitation and seeding density in its influence on per-plant seed output. Although per-plot seed production was highest when seeds were not aggregated, per-plant seed output was higher in aggregated patches. Results suggest aggregation of invasive A. triuncialis reduces the detrimental impact of interspecific competition in its invaded community, and that interspecific competition per se has a stronger impact than intraspecific competition.

  15. Entrepreneurial Ecosystems

    NARCIS (Netherlands)

    Stam, F.C.; Spigel, Ben

    2016-01-01

    This paper reviews and discusses the emergent entrepreneurial ecosystem approach. Entrepreneurial ecosystems are defined as a set of interdependent actors and factors coordinated in such a way that they enable productive entrepreneurship within a particular territory. The purpose of this paper is to

  16. Mapping monetary values of ecosystem services in support of developing ecosystem accounts

    NARCIS (Netherlands)

    Sumarga, Elham; Hein, Lars; Edens, Bram; Suwarno, Aritta

    2015-01-01

    Ecosystem accounting has been proposed as a comprehensive, innovative approach to natural capital accounting, and basically involves the biophysical and monetary analysis of ecosystem services in a national accounting framework. Characteristic for ecosystem accounting is the spatial approach

  17. Greater sage-grouse (Centrocercus urophasianus) nesting and brood-rearing microhabitat in Nevada and California—Spatial variation in selection and survival patterns

    Science.gov (United States)

    Coates, Peter S.; Brussee, Brianne E.; Ricca, Mark A.; Dudko, Jonathan E.; Prochazka, Brian G.; Espinosa, Shawn P.; Casazza, Michael L.; Delehanty, David J.

    2017-08-10

    Greater sage-grouse (Centrocercus urophasianus; hereinafter, "sage-grouse") are highly dependent on sagebrush (Artemisia spp.) dominated vegetation communities for food and cover from predators. Although this species requires the presence of sagebrush shrubs in the overstory, it also inhabits a broad geographic distribution with significant gradients in precipitation and temperature that drive variation in sagebrush ecosystem structure and concomitant shrub understory conditions. Variability in understory conditions across the species’ range may be responsible for the sometimes contradictory findings in the scientific literature describing sage-grouse habitat use and selection during important life history stages, such as nesting. To help understand the importance of this variability and to help guide management actions, we evaluated the nesting and brood-rearing microhabitat factors that influence selection and survival patterns in the Great Basin using a large dataset of microhabitat characteristics from study areas spanning northern Nevada and a portion of northeastern California from 2009 to 2016. The spatial and temporal coverage of the dataset provided a powerful opportunity to evaluate microhabitat factors important to sage-grouse reproduction, while also considering habitat variation associated with different climatic conditions and areas affected by wildfire. The summary statistics for numerous microhabitat factors, and the strength of their association with sage-grouse habitat selection and survival, are provided in this report to support decisions by land managers, policy-makers, and others with the best-available science in a timely manner.

  18. 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.

  19. Exotic annual Bromus invasions: Comparisons among species and ecoregions in the western United States [Chapter 2

    Science.gov (United States)

    Matthew L. Brooks; Cynthia S. Brown; Jeanne C. Chambers; Carla M. D' Antonio; Jon E. Keeley; Jayne Belnap

    2016-01-01

    Exotic annual Bromus species are widely recognized for their potential to invade, dominate, and alter the structure and function of ecosystems. In this chapter, we summarize the invasion potential, ecosystem threats, and management strategies for different Bromus species within each of five ecoregions of the western United States. We characterize invasion...

  20. Ecosystem services in ECOCLIM

    DEFF Research Database (Denmark)

    Sørensen, Lise Lotte; Boegh, Eva; Bendtsen, J

    that actions initiated to reduce anthropogenic GHG emissions are sustainable and not destructive to existing ecosystem services. Therefore it is important to address i.e. land use change in relation to the regulating services of the ecosystems, such as carbon sequestration and climate regulation. At present...... a thorough understanding of the ecosystem processes controlling the uptake or emissions of GHG is fundamental. Here we present ECOCLIM in the context of ecosystem services and the experimental studies within ECOCLIM which will lead to an enhanced understanding of Danish ecosystems....

  1. Invading of intrauterine contraceptive device into the sigmoid colon through uterine perforation caused by a blunt trauma.

    Science.gov (United States)

    Davoodabadi, Abdoulhossein; Mohammadzadeh, Mahdi; Amirbeigi, Mahdieh; Jazayeri, Hoda

    2015-01-01

    Intrauterine contraceptive device (IUCD) is relatively safe but still with some serious risks. Uterus perforation is rare and would be fatal. A case of Cu-7 IUCD invading into the sigmoid colon through uterine perforation caused by a pelvic blunt trauma was presented. Our case showed that uterus perforation by an IUCD could induce utero-sigmoid fistula which is likely to be missed. Imaging is required when the patients with IUCD present abdominal pain, particularly with a history of trauma.

  2. Ecosystem thermodynamics

    International Nuclear Information System (INIS)

    Gomez Palacio, German Rau

    1998-01-01

    Ecology is no more a descriptive and self-sufficient science. Many viewpoints are needed simultaneously to give a full coverage of such complex systems: ecosystems. These viewpoints come from physics, chemistry, and nuclear physics, without a new far from equilibrium thermodynamics and without new mathematical tools such as catastrophe theory, fractal theory, cybernetics and network theory, the development of ecosystem science would never have reached the point of today. Some ideas are presented about the importance that concept such as energy, entropy, exergy information and none equilibrium have in the analysis of processes taking place in ecosystems

  3. Increasing Potential Risk of a Global Aquatic Invader in Europe in Contrast to Other Continents under Future Climate Change

    Science.gov (United States)

    Liu, Xuan; Guo, Zhongwei; Ke, Zunwei; Wang, Supen; Li, Yiming

    2011-01-01

    Background Anthropogenically-induced climate change can alter the current climatic habitat of non-native species and can have complex effects on potentially invasive species. Predictions of the potential distributions of invasive species under climate change will provide critical information for future conservation and management strategies. Aquatic ecosystems are particularly vulnerable to invasive species and climate change, but the effect of climate change on invasive species distributions has been rather neglected, especially for notorious global invaders. Methodology/Principal Findings We used ecological niche models (ENMs) to assess the risks and opportunities that climate change presents for the red swamp crayfish (Procambarus clarkii), which is a worldwide aquatic invasive species. Linking the factors of climate, topography, habitat and human influence, we developed predictive models incorporating both native and non-native distribution data of the crayfish to identify present areas of potential distribution and project the effects of future climate change based on a consensus-forecast approach combining the CCCMA and HADCM3 climate models under two emission scenarios (A2a and B2a) by 2050. The minimum temperature from the coldest month, the human footprint and precipitation of the driest quarter contributed most to the species distribution models. Under both the A2a and B2a scenarios, P. clarkii shifted to higher latitudes in continents of both the northern and southern hemispheres. However, the effect of climate change varied considerately among continents with an expanding potential in Europe and contracting changes in others. Conclusions/Significance Our findings are the first to predict the impact of climate change on the future distribution of a globally invasive aquatic species. We confirmed the complexities of the likely effects of climate change on the potential distribution of globally invasive species, and it is extremely important to develop

  4. Conceptualising the interactive effects of climate change and biological invasions on subarctic freshwater fish.

    Science.gov (United States)

    Rolls, Robert J; Hayden, Brian; Kahilainen, Kimmo K

    2017-06-01

    Climate change and species invasions represent key threats to global biodiversity. Subarctic freshwaters are sentinels for understanding both stressors because the effects of climate change are disproportionately strong at high latitudes and invasion of temperate species is prevalent. Here, we summarize the environmental effects of climate change and illustrate the ecological responses of freshwater fishes to these effects, spanning individual, population, community and ecosystem levels. Climate change is modifying hydrological cycles across atmospheric, terrestrial and aquatic components of subarctic ecosystems, causing increases in ambient water temperature and nutrient availability. These changes affect the individual behavior, habitat use, growth and metabolism, alter population spawning and recruitment dynamics, leading to changes in species abundance and distribution, modify food web structure, trophic interactions and energy flow within communities and change the sources, quantity and quality of energy and nutrients in ecosystems. Increases in temperature and its variability in aquatic environments underpin many ecological responses; however, altered hydrological regimes, increasing nutrient inputs and shortened ice cover are also important drivers of climate change effects and likely contribute to context-dependent responses. Species invasions are a complex aspect of the ecology of climate change because the phenomena of invasion are both an effect and a driver of the ecological consequences of climate change. Using subarctic freshwaters as an example, we illustrate how climate change can alter three distinct aspects of species invasions: (1) the vulnerability of ecosystems to be invaded, (2) the potential for species to spread and invade new habitats, and (3) the subsequent ecological effects of invaders. We identify three fundamental knowledge gaps focused on the need to determine (1) how environmental and landscape characteristics influence the

  5. Ecosystem Under Construction: An Action Research Study on Entrepreneurship in a Business Ecosystem

    Directory of Open Access Journals (Sweden)

    Leni Kuivaniemi

    2012-06-01

    Full Text Available In recent years, we have seen increasing interest in new service concepts that take advantage of the capabilities of business ecosystems instead of single companies. In this article, we describe how a business ecosystem begins to develop around a service business idea proposed by an entrepreneur. We aim to recognize the different domains of players that are or should be involved in the ecosystem while it is under construction. The article concludes with an ecosystem model consisting of six sub-ecosystems having different change drivers and clockspeeds.

  6. The value of producing food, energy, and ecosystem services within an agro-ecosystem

    DEFF Research Database (Denmark)

    Porter, John Roy; Constanza, Robert; Sandhu, Harpinder

    2009-01-01

    Ecosystem Services within an Agro- Ecosystem Agricultural ecosystems produce food, fiber, and nonmarketed ecosystem services (ES). Agriculture also typically involves high negative external costs associated with, for example, fossil fuel use. We estimated, via fieldscale ecological monitoring...... and economic value-transfer methods, the market and nonmarket ES value of a combined food and energy (CFE) agro-ecosystem that simultaneously produces food, fodder, and bioenergy. Such novel CFE agro-ecosystems can provide a significantly increased net crop, energy, and nonmarketed ES compared...... with conventional agriculture, and require markedly less fossil-based inputs. Extrapolated to the European scale, the value of nonmarket ES from the CFE system exceeds current European farm subsidy payments. Such integrated food and bioenergy systems can thus provide environmental value for money for European Union...

  7. Using landscape limnology to classify freshwater ecosystems for multi-ecosystem management and conservation

    Science.gov (United States)

    Soranno, Patricia A.; Cheruvelil, Kendra Spence; Webster, Katherine E.; Bremigan, Mary T.; Wagner, Tyler; Stow, Craig A.

    2010-01-01

    Governmental entities are responsible for managing and conserving large numbers of lake, river, and wetland ecosystems that can be addressed only rarely on a case-by-case basis. We present a system for predictive classification modeling, grounded in the theoretical foundation of landscape limnology, that creates a tractable number of ecosystem classes to which management actions may be tailored. We demonstrate our system by applying two types of predictive classification modeling approaches to develop nutrient criteria for eutrophication management in 1998 north temperate lakes. Our predictive classification system promotes the effective management of multiple ecosystems across broad geographic scales by explicitly connecting management and conservation goals to the classification modeling approach, considering multiple spatial scales as drivers of ecosystem dynamics, and acknowledging the hierarchical structure of freshwater ecosystems. Such a system is critical for adaptive management of complex mosaics of freshwater ecosystems and for balancing competing needs for ecosystem services in a changing world.

  8. First Remote Measurements Of Smoke On The Ground At Night

    Science.gov (United States)

    Gary L. Achtemeier

    1998-01-01

    1. IntroductionFire is recognized as a fundamental ecological process in many forest and rangeland ecosystems throughout the U.S. Ecosystems depend upon fire for health, reproduction, and protection from invading species. The Southern States are leaders in using prescribed fire and understanding its effects. Approximately 200 million acres of forest land are...

  9. Indicators of biodiversity and ecosystem services: A synthesis across ecosystems and spatial scales

    Science.gov (United States)

    Feld, C.K.; Da Silva, P.M.; Sousa, J.P.; De Bello, F.; Bugter, R.; Grandin, U.; Hering, D.; Lavorel, S.; Mountford, O.; Pardo, I.; Partel, M.; Rombke, J.; Sandin, Leonard; Jones, K. Bruce; Harrison, P.

    2009-01-01

    According to the Millennium Ecosystem Assessment, common indicators are needed to monitor the loss of biodiversity and the implications for the sustainable provision of ecosystem services. However, a variety of indicators are already being used resulting in many, mostly incompatible, monitoring systems. In order to synthesise the different indicator approaches and to detect gaps in the development of common indicator systems, we examined 531 indicators that have been reported in 617 peer-reviewed journal articles between 1997 and 2007. Special emphasis was placed on comparing indicators of biodiversity and ecosystem services across ecosystems (forests, grass- and shrublands, wetlands, rivers, lakes, soils and agro-ecosystems) and spatial scales (from patch to global scale). The application of biological indicators was found most often focused on regional and finer spatial scales with few indicators applied across ecosystem types. Abiotic indicators, such as physico-chemical parameters and measures of area and fragmentation, are most frequently used at broader (regional to continental) scales. Despite its multiple dimensions, biodiversity is usually equated with species richness only. The functional, structural and genetic components of biodiversity are poorly addressed despite their potential value across habitats and scales. Ecosystem service indicators are mostly used to estimate regulating and supporting services but generally differ between ecosystem types as they reflect ecosystem-specific services. Despite great effort to develop indicator systems over the past decade, there is still a considerable gap in the widespread use of indicators for many of the multiple components of biodiversity and ecosystem services, and a need to develop common monitoring schemes within and across habitats. Filling these gaps is a prerequisite for linking biodiversity dynamics with ecosystem service delivery and to achieving the goals of global and sub-global initiatives to halt

  10. Coastal ecosystems, productivity and ecosystem protection: Coastal ecosystem management

    International Nuclear Information System (INIS)

    Ngoile, M.A.K.; Horrill, C.J.

    1993-01-01

    The coastal zone is a complex ecosystem under the influence of physical, chemical and biological processes. Under natural conditions these processes interact and maintain an equilibrium in the coastal ecosystem. Man makes a variety of important uses of coastal resources, ranging from harvesting of living resources, extraction of nonliving resources, and recreation, to the disposal of wastes. Man's extensive use of the oceans introduces factors which bring about an imbalance in the natural processes, and may result in harmful and hazardous effects to life hindering further use. Man's pressure on the resources of the coastal zone is already manifest and will increase manifold. This calls for an immediate solution to the protection and sustainable use of coastal resources. The current sectorized approach to the management of human activities will not solve the problem because the different resources of the coastal zone interact in such a manner that disturbances in one cause imbalance in the others. This is further complicated by the sectorized approach to research and limited communication between policy makers, managers, and scientists. This paper discusses strategies for managing coastal-resources use through an integrated approach. The coastal zone is presented as a unified ecosystem in equilibrium and shows that man's extensive use of the coastal resources destabilizes this equilibrium. Examples from the East Africa Region are presented. 15 refs, 2 figs, 3 tabs

  11. Horizontal and vertical variability of soil moisture in savanna ecosystems

    Science.gov (United States)

    Caylor, K.; D'Odorico, P.; Rodriguez-Iturbe, I.

    2004-12-01

    Soil moisture is a key hydrological variable that mediates the interactions between climate, soil, and vegetation dynamics in water-limited ecosystems. Because of the importance of water limitation in savannas, a number of theoretical models of tree-grass coexistence have been developed which differ in their underlying assumptions about the ways in which trees and grasses access and use soil moisture. However, clarification of the mechanisms that allow savanna vegetation to persist as a mixture of grasses and trees remains a vexing problem in both hydrological and vegetation science. A particular challenge is the fact that the spatial pattern of vegetation is both a cause and effect of variation in water availability in semiarid ecosystems. At landscape to regional scales, climatic and geologic constraints on soil moisture availability are primary determinants of vegetation structural pattern. However, at local to landscape scales the patchy vegetation structural mosaic serves to redistribute the availability of soil moisture in ways that have important consequences for structural dynamics and community composition. In this regard, the emerging field of ecohydrology is well suited to investigate questions concerning couplings between the patchy structural mosaic of savanna vegetation and the kinds self-organizing dynamics known to exist in other light and nutrient-limited vegetation systems. Here we address the role of patchy vegetation structure through the use of a lumped model of soil moisture dynamics that accounts for the effect of tree canopy on the lateral and vertical distribution of soil moisture. The model includes mechanisms for the drying of the ground surface due to soil evaporation in the sites with no tree cover, and for the lateral water uptake due to root invading areas with no canopy cover located in the proximity of trees. The model, when applied to a series of sites along a rainfall gradient in southern Africa, is able to explain the cover

  12. Ecosystem services science, practice, and policy: Perspectives from ACES, A Community on Ecosystem Services

    Science.gov (United States)

    Shapiro, Carl D.; Arthaud, Greg; Casey, Frank; Hogan, Dianna M.

    2015-01-01

    Ecosystem services are at a crossroad. The natural capital needed to produce them is diminishing (Millennium Ecosystem Assessment, 2005). At the same time, the science relating to their identification, production, and valuation is advancing. Examples of ecosystem services applications are abundant in the literature. In addition, the concept of ecosystem services and its applications are attracting attention and are becoming more visible. The concept of ecosystem services, however, is still not routinely applied to many natural resource management decisions.

  13. BUSINESS ECOSYSTEMS VS BUSINESS DIGITAL ECOSYSTEMS

    Directory of Open Access Journals (Sweden)

    Marinela Lazarica

    2006-05-01

    Full Text Available E-business is often described as the small organisations’ gateway to global business and markets. The adoption of Internet-based technologies for e-business is a continuous process, with sequential steps of evolution. The latter step in the adoption of Internet-based technologies for business, where the business services and the software components are supported by a pervasive software environment, which shows an evolutionary and self-organising behaviour are named digital business ecosystems. The digital business ecosystems are characterized by intelligent software components and services, knowledge transfer, interactive training frameworks and integration of business processes and e-government models.

  14. A primer on potential impacts, management priorities, and future directions for Elodea spp. in high latitude systems: learning from the Alaskan experience

    Science.gov (United States)

    Carey, Michael P.; Sethi, Suresh A; Larsen, Sabrina J; Rich, Cecil F

    2016-01-01

    Invasive species introductions in Arctic and Subarctic ecosystems are growing as climate change manifests and human activity increases in high latitudes. The aquatic plants of the genus Elodea are potential invaders to Arctic and Subarctic ecosystems circumpolar and at least one species is already established in Alaska, USA. To illustrate the problems of preventing, eradicating, containing, and mitigating aquatic, invasive plants in Arctic and Subarctic ecosystems, we review the invasion dynamics of Elodea and provide recommendations for research and management efforts in Alaska. Foremost, we conclude the remoteness of Arctic and Subarctic systems such as Alaska is no longer a protective attribute against invasions, as transportation pathways now reach throughout these regions. Rather, high costs of operating in remote Arctic and Subarctic systems hinders detection of infestations and limits eradication or mitigation, emphasizing management priorities of prevention and containment of aquatic plant invaders in Alaska and other Arctic and Subarctic systems.

  15. Ecosystem approach in education

    Science.gov (United States)

    Nabiullin, Iskander

    2017-04-01

    Environmental education is a base for sustainable development. Therefore, in our school we pay great attention to environmental education. Environmental education in our school is based on ecosystem approach. What is an ecosystem approach? Ecosystem is a fundamental concept of ecology. Living organisms and their non-living environments interact with each other as a system, and the biosphere planet functions as a global ecosystem. Therefore, it is necessary for children to understand relationships in ecosystems, and we have to develop systems thinking in our students. Ecosystem approach and systems thinking should help us to solve global environmental problems. How do we implement the ecosystem approach? Students must understand that our biosphere functions as a single ecosystem and even small changes can lead to environmental disasters. Even the disappearance of one plant or animal species can lead to irreversible consequences. So in the classroom we learn the importance of each living organism for the nature. We pay special attention to endangered species, which are listed in the Red Data List. Kids are doing projects about these organisms, make videos, print brochures and newspapers. Fieldwork also plays an important role for ecosystem approach. Every summer, we go out for expeditions to study species of plants and animals listed in the Red Data List of Tatarstan. In class, students often write essays on behalf of any endangered species of plants or animals, this also helps them to understand the importance of each living organism in nature. Each spring we organise a festival of environmental projects among students. Groups of 4-5 students work on a solution of environmental problems, such as water, air or soil pollution, waste recycling, the loss of biodiversity, etc. Participants shoot a clip about their project, print brochures. Furthermore, some of the students participate in national and international scientific Olympiads with their projects. In addition to

  16. Progress and challenges in the development of ecosystem accounting as a tool to analyse ecosystem capital

    NARCIS (Netherlands)

    Hein, Lars; Obst, Carl; Edens, Bram; Remme, R.P.

    2015-01-01

    Ecosystem accounting has been developed as a systematic approach to incorporate measures of ecosystem services and ecosystem assets into an accounting structure. Ecosystem accounting involves spatially explicit modelling of ecosystem services and assets, in both physical and monetary terms. A

  17. Global Ecosystem Restoration Index

    DEFF Research Database (Denmark)

    Fernandez, Miguel; Garcia, Monica; Fernandez, Nestor

    2015-01-01

    The Global ecosystem restoration index (GERI) is a composite index that integrates structural and functional aspects of the ecosystem restoration process. These elements are evaluated through a window that looks into a baseline for degraded ecosystems with the objective to assess restoration...

  18. Rights to ecosystem services

    NARCIS (Netherlands)

    Davidson, M.

    2014-01-01

    Ecosystem services are the benefits people obtain from ecosystems. Many of these services are provided outside the borders of the land where they are produced; this article investigates who is entitled to these non-excludable ecosystem services from two libertarian perspectives. Taking a

  19. Radio-capacity of ecosystems

    International Nuclear Information System (INIS)

    Kultakhmedov, Yu.; Kultakhmedova-Vyshnyakova, V.

    1997-01-01

    This paper consider a universal approach to ecosystems of different types, based on representation of their radio-capacity. The concept of ecosystem includes reproduction of components (bio-productivity) and conditions such as maintaining of environment quality. Radio-capacity in the case of radionuclide pollution appears in accumulation and redistribution of radionuclides in the ecosystem. As a result the radionuclides are redistributed and buried in soil or lake bottom sediments. Estimation models for the radio-capacity of water and terrestrial ecosystems are represented. The calculations of the radio-capacity factor of water ecosystems are performed, and the high radio-capacity of a freshwater reservoir (F=0.6-0.8) and extremely high radio-capacity of a reservoir cascade (F c =0.99) is shown material from the Dnieper's cascade reservoirs. The methods of radio-capacity estimation of agroecosystems, wood and marine ecosystems are developed. (authors)

  20. 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

  1. Monetary accounting of ecosystem services

    NARCIS (Netherlands)

    Remme, R.P.; Edens, Bram; Schröter, Matthias; Hein, Lars

    2015-01-01

    Ecosystem accounting aims to provide a better understanding of ecosystem contributions to the economy in a spatially explicit way. Ecosystem accounting monitors ecosystem services and measures their monetary value using exchange values consistent with the System of National Accounts (SNA). We

  2. Greater sage-grouse winter habitat use on the eastern edge of their range

    Science.gov (United States)

    Swanson, Christopher C.; Rumble, Mark A.; Grovenburg, Troy W.; Kaczor, Nicholas W.; Klaver, Robert W.; Herman-Brunson, Katie M.; Jenks, Jonathan A.; Jensen, Kent C.

    2013-01-01

    Greater sage-grouse (Centrocercus urophasianus) at the western edge of the Dakotas occur in the transition zone between sagebrush and grassland communities. These mixed sagebrush (Artemisia sp.) and grasslands differ from those habitats that comprise the central portions of the sage-grouse range; yet, no information is available on winter habitat selection within this region of their distribution. We evaluated factors influencing greater sage-grouse winter habitat use in North Dakota during 2005–2006 and 2006–2007 and in South Dakota during 2006–2007 and 2007–2008. We captured and radio-marked 97 breeding-age females and 54 breeding-age males from 2005 to 2007 and quantified habitat selection for 98 of these birds that were alive during winter. We collected habitat measurements at 340 (177 ND, 163 SD) sage-grouse use sites and 680 random (340 each at 250 m and 500 m from locations) dependent sites. Use sites differed from random sites with greater percent sagebrush cover (14.75% use vs. 7.29% random; P 2 use vs. 0.94 plants/m2 random; P ≤ 0.001), but lesser percent grass cover (11.76% use vs. 16.01% random; P ≤ 0.001) and litter cover (4.34% use vs. 5.55% random; P = 0.001) and lower sagebrush height (20.02 cm use vs. 21.35 cm random; P = 0.13) and grass height (21.47 cm use vs. 23.21 cm random; P = 0.15). We used conditional logistic regression to estimate winter habitat selection by sage-grouse on continuous scales. The model sagebrush cover + sagebrush height + sagebrush cover × sagebrush height (wi = 0.60) was the most supported of the 13 models we considered, indicating that percent sagebrush cover strongly influenced selection. Logistic odds ratios indicated that the probability of selection by sage-grouse increased by 1.867 for every 1% increase in sagebrush cover (95% CI = 1.627–2.141) and by 1.041 for every 1 cm increase in sagebrush height (95% CI = 1.002–1.082). The

  3. Consumer-driven nutrient dynamics in freshwater ecosystems: from individuals to ecosystems.

    Science.gov (United States)

    Atkinson, Carla L; Capps, Krista A; Rugenski, Amanda T; Vanni, Michael J

    2017-11-01

    The role of animals in modulating nutrient cycling [hereafter, consumer-driven nutrient dynamics (CND)] has been accepted as an important influence on both community structure and ecosystem function in aquatic systems. Yet there is great variability in the influence of CND across species and ecosystems, and the causes of this variation are not well understood. Here, we review and synthesize the mechanisms behind CND in fresh waters. We reviewed 131 articles on CND published between 1973 and 1 June 2015. The rate of new publications in CND has increased from 1.4 papers per year during 1973-2002 to 7.3 per year during 2003-2015. The majority of investigations are in North America with many concentrating on fish. More recent studies have focused on animal-mediated nutrient excretion rates relative to nutrient demand and indirect impacts (e.g. decomposition). We identified several mechanisms that influence CND across levels of biological organization. Factors affecting the stoichiometric plasticity of consumers, including body size, feeding history and ontogeny, play an important role in determining the impact of individual consumers on nutrient dynamics and underlie the stoichiometry of CND across time and space. The abiotic characteristics of an ecosystem affect the net impact of consumers on ecosystem processes by influencing consumer metabolic processes (e.g. consumption and excretion/egestion rates), non-CND supply of nutrients and ecosystem nutrient demand. Furthermore, the transformation and transport of elements by populations and communities of consumers also influences the flow of energy and nutrients across ecosystem boundaries. This review highlights that shifts in community composition or biomass of consumers and eco-evolutionary underpinnings can have strong effects on the functional role of consumers in ecosystem processes, yet these are relatively unexplored aspects of CND. Future research should evaluate the value of using species traits and abiotic

  4. Invading stacking primer: A trigger for high-efficiency isothermal amplification reaction with superior selectivity for detecting microRNA variants.

    Science.gov (United States)

    Liu, Weipeng; Zhu, Minjun; Liu, Hongxing; Wei, Jitao; Zhou, Xiaoming; Xing, Da

    2016-07-15

    Searching for a strategy to enhance the efficiency of nucleic acid amplification and achieve exquisite discrimination of nucleic acids at the single-base level for biological detection has become an exciting research direction in recent years. Here, we have developed a simple and universal primer design strategy which produces a fascinating effect on isothermal strand displacement amplification (iSDA). We refer to the resultant primer as "invading stacking primer (IS-Primer)" which is based on contiguous stacking hybridization and toehold-mediated exchange reaction and function by merely changing the hybridization location of the primer. Using the IS-Primer, the sensitivity in detecting the target miR-21 is improved approximately five fold compared with the traditional iSDA reaction. It was further demonstrated that the IS-Primer acts as an invading strand to initiate branch migration which can increase the efficiency of the untwisting of the hairpin probe. This effect is equivalent to reducing the free energy of the stem, and the technique shows superior selectivity for single-base mismatches. By demonstrating the enhanced effect of the IS-Primer in the iSDA reaction, this work may provide a potentially new avenue for developing more sensitive and selective nucleic acids assays. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Lessons learned for spatial modelling of ecosystem services in support of ecosystem accounting

    NARCIS (Netherlands)

    Schroter, M.; Remme, R.P.; Sumarga, E.; Barton, D.N.; Hein, L.G.

    2015-01-01

    Assessment of ecosystem services through spatial modelling plays a key role in ecosystem accounting. Spatial models for ecosystem services try to capture spatial heterogeneity with high accuracy. This endeavour, however, faces several practical constraints. In this article we analyse the trade-offs

  6. Competitive helping increases with the size of biological markets and invades defection.

    Science.gov (United States)

    Barclay, Pat

    2011-07-21

    Cooperation between unrelated individuals remains a puzzle in evolutionary biology. Recent work indicates that partner choice can select for high levels of helping. More generally, helping can be seen as but one strategy used to compete for partners within a broader biological market, yet giving within such markets has received little mathematical investigation. In the present model, individuals help others to attract attention from them and thus receive a larger share of any help actively or passively provided by those others. The evolutionarily stable level of helping increases with the size of the biological market and the degree of partner choice. Furthermore, if individuals passively produce some no-cost help to partners, competitive helping can then invade populations of non-helpers because helpers directly benefit from increasing their access to potential partners. This framework of competitive helping demonstrates how high helping can be achieved and why different populations may differ in helping levels. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. [Research progress of ecosystem service flow.

    Science.gov (United States)

    Liu, Hui Min; Fan, Yu Long; Ding, Sheng Yan

    2016-07-01

    With the development of social economy, human disturbance has resulted in a variety of ecosystem service degradation or disappearance. Ecosystem services flow plays an important role in delivery, transformation and maintenance of ecosystem services, and becomes one of the new research directions. In this paper, based on the classification of ecosystem services flow, we analyzed ecosystem service delivery carrier, and investigated the mechanism of ecosystem service flow, including the information, property, scale features, quantification and cartography. Moreover, a tentative analysis on cost-effective of ecosystem services flow (such as transportation costs, conversion costs, usage costs and cost of relativity) was made to analyze the consumption cost in ecosystem services flow process. It aimed to analyze dissipation cost in ecosystem services flow process. To a certain extent, the study of ecosystem service flow solved the problem of "double counting" in ecosystem services valuation, which could make a contribution for the sake of recognizing hot supply and consumption spots of ecosystem services. In addition, it would be conducive to maximizing the ecosystem service benefits in the transmission process and putting forward scientific and reasonable ecological compensation.

  8. Incorporating historical ecosystem diversity into conservation planning efforts in grass and shrub ecosystems

    Science.gov (United States)

    Amy C. Ganguli; Johathan B. Haufler; Carolyn A. Mehl; Jimmie D. Chew

    2011-01-01

    Understanding historical ecosystem diversity and wildlife habitat quality can provide a useful reference for managing and restoring rangeland ecosystems. We characterized historical ecosystem diversity using available empirical data, expert opinion, and the spatially explicit vegetation dynamics model SIMPPLLE (SIMulating Vegetative Patterns and Processes at Landscape...

  9. On Man and Ecosystems.

    Science.gov (United States)

    Brookfield, Harold

    1982-01-01

    Distinctions between natural ecosystems and human ecosystems are misleading. Natural and social sciences can be integrated through the concept of a "human-use ecosystem," in which social scientists analyze the community, household, and individual, and natural scientists analyze the land. Includes a case study of St. Kitts. (KC)

  10. Mapping cultural ecosystem services:

    DEFF Research Database (Denmark)

    Paracchini, Maria Luisa; Zulian, Grazia; Kopperoinen, Leena

    2014-01-01

    Research on ecosystem services mapping and valuing has increased significantly in recent years. However, compared to provisioning and regulating services, cultural ecosystem services have not yet been fully integrated into operational frameworks. One reason for this is that transdisciplinarity...... surveys are a main source of information. Among cultural ecosystem services, assessment of outdoor recreation can be based on a large pool of literature developed mostly in social and medical science, and landscape and ecology studies. This paper presents a methodology to include recreation...... in the conceptual framework for EU wide ecosystem assessments (Maes et al., 2013), which couples existing approaches for recreation management at country level with behavioural data derived from surveys, and population distribution data. The proposed framework is based on three components: the ecosystem function...

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

    Science.gov (United States)

    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

  12. Capability-Driven Design of Business Service Ecosystem to Support Risk Governance in Regulatory Ecosystems

    Directory of Open Access Journals (Sweden)

    Christophe Feltus

    2017-04-01

    Full Text Available Risk-based regulation and risk governance gain momentum in most sectorial ecosystems, should they be the finance, the healthcare or the telecommunications ecosystems. Although there is a profusion of tools to address this issue at the corporate level, worth is to note that no solution fulfils this function at the ecosystem level yet. Therefore, in this article, the Business Service Ecosystem (BSE metamodel is semantically extended, considering the Capability as a Service (CaaS theory, in order to raise the enterprise risk management from the enterprise level up to the ecosystem level. This extension allows defining a concrete ecosystem metamodel which is afterwards mapped with an information system risk management model to support risk governance at the ecosystem level. This mapping is illustrated and validated on the basis of an application case for the Luxembourgish financial sector applied to the most important concepts from the BSE: capability, resource, service and goal.

  13. From theoretical to actual ecosystem services: mapping beneficiaries and spatial flows in ecosystem service assessments

    Directory of Open Access Journals (Sweden)

    Kenneth J. Bagstad

    2014-06-01

    Full Text Available Ecosystem services mapping and modeling has focused more on supply than demand, until recently. Whereas the potential provision of economic benefits from ecosystems to people is often quantified through ecological production functions, the use of and demand for ecosystem services has received less attention, as have the spatial flows of services from ecosystems to people. However, new modeling approaches that map and quantify service-specific sources (ecosystem capacity to provide a service, sinks (biophysical or anthropogenic features that deplete or alter service flows, users (user locations and level of demand, and spatial flows can provide a more complete understanding of ecosystem services. Through a case study in Puget Sound, Washington State, USA, we quantify and differentiate between the theoretical or in situ provision of services, i.e., ecosystems' capacity to supply services, and their actual provision when accounting for the location of beneficiaries and the spatial connections that mediate service flows between people and ecosystems. Our analysis includes five ecosystem services: carbon sequestration and storage, riverine flood regulation, sediment regulation for reservoirs, open space proximity, and scenic viewsheds. Each ecosystem service is characterized by different beneficiary groups and means of service flow. Using the ARtificial Intelligence for Ecosystem Services (ARIES methodology we map service supply, demand, and flow, extending on simpler approaches used by past studies to map service provision and use. With the exception of the carbon sequestration service, regions that actually provided services to people, i.e., connected to beneficiaries via flow paths, amounted to 16-66% of those theoretically capable of supplying services, i.e., all ecosystems across the landscape. These results offer a more complete understanding of the spatial dynamics of ecosystem services and their effects, and may provide a sounder basis for

  14. Didymosphenia geminata invasion in South America: Ecosystem impacts and potential biogeochemical state change in Patagonian rivers

    Science.gov (United States)

    Reid, Brian; Torres, Rodrigo

    2014-01-01

    The diatom Didymosphenia geminata has emerged as a major global concern, as both an aggressive invader of rivers and streams in the southern hemisphere, and for its ability to form nuisance blooms in oligotrophic systems in its native range. South American D. geminata blooms were first documented in Chilean Patagonia in May 2010, and have spread to over five regions and three provinces, in Chile and Argentina respectively. The Patagonian invasion represents a distinct challenge compared to other regions; not only are affected systems poorly characterized, but also a general synthesis of the nature and magnitude of ecosystem impacts is still lacking. The latter is essential in evaluating impacts to ecosystem services, forms the basis for a management response that is proportional to the potentially valid threats, or aids in the determination of whether action is warranted or feasible. Based on a revision of the recent literature, some of the most significant impacts may be mediated through physical changes: substantially increased algal biomass, trapping of fine sediment, altered hydrodynamics, and consequent effects on biogeochemical states and processes such as redox condition, pH and nutrient cycling in the benthic zone. Surveys conducted during the early invasion in Chile show a strong correlation between benthic biomass and associated fine sediments, both of which were one-two orders of magnitude higher within D. geminata blooms. Experimental phosphorous amendments showed significant abiotic uptake, while interstitial water in D. geminata mats had nearly 10-20 fold higher soluble reactive phosphorous and a pronounced pH cycle compared to the water column. A dominant and aggressive stalk-forming diatom with this combination of characteristics is in sharp contrast to the colonial cyanobacteria and bare gravel substrate that characterize many Patagonian streams. The potential displacement of native benthic algal communities with contrasting functional groups

  15. Non-Native Plant Invasion along Elevation and Canopy Closure Gradients in a Middle Rocky Mountain Ecosystem.

    Directory of Open Access Journals (Sweden)

    Joshua P Averett

    Full Text Available Mountain environments are currently among the ecosystems least invaded by non-native species; however, mountains are increasingly under threat of non-native plant invasion. The slow pace of exotic plant invasions in mountain ecosystems is likely due to a combination of low anthropogenic disturbances, low propagule supply, and extreme/steep environmental gradients. The importance of any one of these factors is debated and likely ecosystem dependent. We evaluated the importance of various correlates of plant invasions in the Wallowa Mountain Range of northeastern Oregon and explored whether non-native species distributions differed from native species along an elevation gradient. Vascular plant communities were sampled in summer 2012 along three mountain roads. Transects (n = 20 were evenly stratified by elevation (~70 m intervals along each road. Vascular plant species abundances and environmental parameters were measured. We used indicator species analysis to identify habitat affinities for non-native species. Plots were ordinated in species space, joint plots and non-parametric multiplicative regression were used to relate species and community variation to environmental variables. Non-native species richness decreased continuously with increasing elevation. In contrast, native species richness displayed a unimodal distribution with maximum richness occurring at mid-elevations. Species composition was strongly related to elevation and canopy openness. Overlays of trait and environmental factors onto non-metric multidimensional ordinations identified the montane-subalpine community transition and over-story canopy closure exceeding 60% as potential barriers to non-native species establishment. Unlike native species, non-native species showed little evidence for high-elevation or closed-canopy specialization. These data suggest that non-native plants currently found in the Wallowa Mountains are dependent on open canopies and disturbance for

  16. Non-Native Plant Invasion along Elevation and Canopy Closure Gradients in a Middle Rocky Mountain Ecosystem.

    Science.gov (United States)

    Averett, Joshua P; McCune, Bruce; Parks, Catherine G; Naylor, Bridgett J; DelCurto, Tim; Mata-González, Ricardo

    2016-01-01

    Mountain environments are currently among the ecosystems least invaded by non-native species; however, mountains are increasingly under threat of non-native plant invasion. The slow pace of exotic plant invasions in mountain ecosystems is likely due to a combination of low anthropogenic disturbances, low propagule supply, and extreme/steep environmental gradients. The importance of any one of these factors is debated and likely ecosystem dependent. We evaluated the importance of various correlates of plant invasions in the Wallowa Mountain Range of northeastern Oregon and explored whether non-native species distributions differed from native species along an elevation gradient. Vascular plant communities were sampled in summer 2012 along three mountain roads. Transects (n = 20) were evenly stratified by elevation (~70 m intervals) along each road. Vascular plant species abundances and environmental parameters were measured. We used indicator species analysis to identify habitat affinities for non-native species. Plots were ordinated in species space, joint plots and non-parametric multiplicative regression were used to relate species and community variation to environmental variables. Non-native species richness decreased continuously with increasing elevation. In contrast, native species richness displayed a unimodal distribution with maximum richness occurring at mid-elevations. Species composition was strongly related to elevation and canopy openness. Overlays of trait and environmental factors onto non-metric multidimensional ordinations identified the montane-subalpine community transition and over-story canopy closure exceeding 60% as potential barriers to non-native species establishment. Unlike native species, non-native species showed little evidence for high-elevation or closed-canopy specialization. These data suggest that non-native plants currently found in the Wallowa Mountains are dependent on open canopies and disturbance for establishment in low

  17. Inverted papilloma of lacrimal sac invading into the orbit: Case report and review of literature

    Directory of Open Access Journals (Sweden)

    Alistair W Hardy

    2015-01-01

    Full Text Available Inverted papilloma (IP is a sinonasal tumor of benign etiology with local invasion and malignant potential. IP arising in lacrimal sac invading the orbit is extremely rare with only one case reported so far. The presented case appears to be the second such case reported in the literature. A 60-year-old Caucasian male presented with a medial canthal mass and epiphora. Incisional biopsy confirmed a transitional neoplasm. The lesion was completely excised enbloc with clear margins by using a Weber-Ferguson incision; orbital clearance and nasolacrimalfossa clearance was achieved via a medial maxillectomy. Enbloc resection of orbital and nasolacrimal parts of the tumor with clear margins is recommended.

  18. Perception, acquisition and use of ecosystem services: human behavior, and ecosystem management and policy implications

    Science.gov (United States)

    Stanley T. Asah; Anne D. Guerry; Dale J. Blahna; Joshua J. Lawler

    2014-01-01

    Ecosystem services, fundamental to livelihoods and well-being, are reshaping environmental management and policy. However, the behavioral dimensions of ecosystem services and the responses of ordinary people to the management of those services, is less well understood. The ecosystem services framework lends itself to understanding the relationship between ecosystems...

  19. Ecosystem Management. A Management View

    DEFF Research Database (Denmark)

    Ravn-Jonsen, Lars

    The need for management of the marine ecosystem using a broad perspective has been recommended under a variety of names. This paper uses the term Ecosystem Management, which is seen as a convergence between the ecological idea of an organisational hierarchy and the idea of strategic planning...... with a planning hierarchy---with the ecosystem being the strategic planning level. Management planning requires, in order to establish a quantifiable means and ends chain, that the goals at the ecosystem level can be linked to operational levels; ecosystem properties must therefore be reducible to lower...... organisational levels. Emergence caused by constraints at both the component and system levels gives rise to phenomena that can create links between the ecosystem and operational levels. To create these links, the ecosystem's functional elements must be grouped according to their functionality, ignoring any...

  20. Going beyond the Millennium Ecosystem Assessment: an index system of human dependence on ecosystem services.

    Science.gov (United States)

    Yang, Wu; Dietz, Thomas; Liu, Wei; Luo, Junyan; Liu, Jianguo

    2013-01-01

    The Millennium Ecosystem Assessment (MA) estimated that two thirds of ecosystem services on the earth have degraded or are in decline due to the unprecedented scale of human activities during recent decades. These changes will have tremendous consequences for human well-being, and offer both risks and opportunities for a wide range of stakeholders. Yet these risks and opportunities have not been well managed due in part to the lack of quantitative understanding of human dependence on ecosystem services. Here, we propose an index of dependence on ecosystem services (IDES) system to quantify human dependence on ecosystem services. We demonstrate the construction of the IDES system using household survey data. We show that the overall index and sub-indices can reflect the general pattern of households' dependences on ecosystem services, and their variations across time, space, and different forms of capital (i.e., natural, human, financial, manufactured, and social capitals). We support the proposition that the poor are more dependent on ecosystem services and further generalize this proposition by arguing that those disadvantaged groups who possess low levels of any form of capital except for natural capital are more dependent on ecosystem services than those with greater control of capital. The higher value of the overall IDES or sub-index represents the higher dependence on the corresponding ecosystem services, and thus the higher vulnerability to the degradation or decline of corresponding ecosystem services. The IDES system improves our understanding of human dependence on ecosystem services. It also provides insights into strategies for alleviating poverty, for targeting priority groups of conservation programs, and for managing risks and opportunities due to changes of ecosystem services at multiple scales.

  1. Ecosystem Services : In Nordic Freshwater Management

    DEFF Research Database (Denmark)

    Magnussen, Kristin; Hasler, Berit; Zandersen, Marianne

    Human wellbeing is dependent upon and benefit from ecosystem services which are delivered by well-functioning ecosystems. Ecosystem services can be mapped and assessed consistently within an ecosystem service framework. This project aims to explore the use and usefulness of the ecosystem service ...

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

    Science.gov (United States)

    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.

  3. Ecosystem classification, Chapter 2

    Science.gov (United States)

    M.J. Robin-Abbott; L.H. Pardo

    2011-01-01

    The ecosystem classification in this report is based on the ecoregions developed through the Commission for Environmental Cooperation (CEC) for North America (CEC 1997). Only ecosystems that occur in the United States are included. CEC ecoregions are described, with slight modifications, below (CEC 1997) and shown in Figures 2.1 and 2.2. We chose this ecosystem...

  4. From theoretical to actual ecosystem services: mapping beneficiaries and spatial flows in ecosystem service assessments

    Science.gov (United States)

    Bagstad, Kenneth J.; Villa, Ferdinando; Batker, David; Harrison-Cox, Jennifer; Voigt, Brian; Johnson, Gary W.

    2014-01-01

    Ecosystem services mapping and modeling has focused more on supply than demand, until recently. Whereas the potential provision of economic benefits from ecosystems to people is often quantified through ecological production functions, the use of and demand for ecosystem services has received less attention, as have the spatial flows of services from ecosystems to people. However, new modeling approaches that map and quantify service-specific sources (ecosystem capacity to provide a service), sinks (biophysical or anthropogenic features that deplete or alter service flows), users (user locations and level of demand), and spatial flows can provide a more complete understanding of ecosystem services. Through a case study in Puget Sound, Washington State, USA, we quantify and differentiate between the theoretical or in situ provision of services, i.e., ecosystems’ capacity to supply services, and their actual provision when accounting for the location of beneficiaries and the spatial connections that mediate service flows between people and ecosystems. Our analysis includes five ecosystem services: carbon sequestration and storage, riverine flood regulation, sediment regulation for reservoirs, open space proximity, and scenic viewsheds. Each ecosystem service is characterized by different beneficiary groups and means of service flow. Using the ARtificial Intelligence for Ecosystem Services (ARIES) methodology we map service supply, demand, and flow, extending on simpler approaches used by past studies to map service provision and use. With the exception of the carbon sequestration service, regions that actually provided services to people, i.e., connected to beneficiaries via flow paths, amounted to 16-66% of those theoretically capable of supplying services, i.e., all ecosystems across the landscape. These results offer a more complete understanding of the spatial dynamics of ecosystem services and their effects, and may provide a sounder basis for economic

  5. Biological invasions: economic and environmental costs of alien plant, animal, and microbe species

    National Research Council Canada - National Science Library

    Pimentel, David

    2011-01-01

    ...: Economic and Environmental Costs of Alien Plant, Animal, and Microbe Species, this reference discusses how non-native species invade new ecosystems and the subsequent economic and environmental effects of these species...

  6. Measuring Entrepreneurial Ecosystems

    NARCIS (Netherlands)

    Stam, F.C.

    How can entrepreneurial ecosystems and productive entrepreneurship can be traced empirically and how is entrepreneurship related to entrepreneurial ecosystems. The analyses in this chapter show the value of taking a systems view on the context of entrepreneurship. We measure entrepreneurial

  7. The biodiversity-dependent ecosystem service debt.

    Science.gov (United States)

    Isbell, Forest; Tilman, David; Polasky, Stephen; Loreau, Michel

    2015-02-01

    Habitat destruction is driving biodiversity loss in remaining ecosystems, and ecosystem functioning and services often directly depend on biodiversity. Thus, biodiversity loss is likely creating an ecosystem service debt: a gradual loss of biodiversity-dependent benefits that people obtain from remaining fragments of natural ecosystems. Here, we develop an approach for quantifying ecosystem service debts, and illustrate its use to estimate how one anthropogenic driver, habitat destruction, could indirectly diminish one ecosystem service, carbon storage, by creating an extinction debt. We estimate that c. 2-21 Pg C could be gradually emitted globally in remaining ecosystem fragments because of plant species loss caused by nearby habitat destruction. The wide range for this estimate reflects substantial uncertainties in how many plant species will be lost, how much species loss will impact ecosystem functioning and whether plant species loss will decrease soil carbon. Our exploratory analysis suggests that biodiversity-dependent ecosystem service debts can be globally substantial, even when locally small, if they occur diffusely across vast areas of remaining ecosystems. There is substantial value in conserving not only the quantity (area), but also the quality (biodiversity) of natural ecosystems for the sustainable provision of ecosystem services. © 2014 John Wiley & Sons Ltd/CNRS.

  8. Elasticity in ecosystem services: exploring the variable relationship between ecosystems and human well-being

    Directory of Open Access Journals (Sweden)

    Tim M. Daw

    2016-06-01

    Full Text Available Although ecosystem services are increasingly recognized as benefits people obtain from nature, we still have a poor understanding of how they actually enhance multidimensional human well-being, and how well-being is affected by ecosystem change. We develop a concept of "ecosystem service elasticity" (ES elasticity that describes the sensitivity of human well-being to changes in ecosystems. ES Elasticity is a result of complex social and ecological dynamics and is context dependent, individually variable, and likely to demonstrate nonlinear dynamics such as thresholds and hysteresis. We present a conceptual framework that unpacks the chain of causality from ecosystem stocks through flows, goods, value, and shares to contribute to the well-being of different people. This framework builds on previous conceptualizations, but places multidimensional well-being of different people as the final element. This ultimately disaggregated approach emphasizes how different people access benefits and how benefits match their needs or aspirations. Applying this framework to case studies of individual coastal ecosystem services in East Africa illustrates a wide range of social and ecological factors that can affect ES elasticity. For example, food web and habitat dynamics affect the sensitivity of different fisheries ecosystem services to ecological change. Meanwhile high cultural significance, or lack of alternatives enhance ES elasticity, while social mechanisms that prevent access can reduce elasticity. Mapping out how chains are interlinked illustrates how different types of value and the well-being of different people are linked to each other and to common ecological stocks. We suggest that examining chains for individual ecosystem services can suggest potential interventions aimed at poverty alleviation and sustainable ecosystems while mapping out of interlinkages between chains can help to identify possible ecosystem service trade-offs and winners and

  9. Ecosystem and Community Responses to Rainfall Manipulations in Shrublands Depends on Dominant Vegetation Cover

    Science.gov (United States)

    Esch, E. H.; Lipson, D.; Kim, J. B.; Cleland, E. E.

    2014-12-01

    Southern California is predicted to face decreasing precipitation with increased interannual variability in the coming century. Native shrublands in this area are increasingly invaded by exotic annual grasses, though invasion dynamics can vary by rainfall scenario, with wet years generally associated with high invasion pressure. Interplay between rainfall and invasion scenarios can influence carbon stocks and community composition. Here we asked how invasion alters ecosystem and community responses in drought versus high rainfall scenarios, as quantified by community identity, biomass production, and the normalized difference vegetation index (NDVI). To do this, we performed a rainfall manipulation experiment with paired plots dominated either by native shrubs or exotic herbaceous species, subjected to treatments of 50%, 100%, or 150% of ambient rainfall. The study site was located in a coastal sage scrub ecosystem, with patches dominated by native shrubs and exotic grasses located in San Diego County, USA. During two growing seasons, we found that native, herbaceous biomass production was significantly affected by rainfall treatment (p<0.05 for both years), though was not affected by dominant community composition. Photosynthetic biomass production of shrub species also varied by treatment (p=0.035). Exotic biomass production showed a significant interaction between dominant community composition and rainfall treatment, and both individual effects (p<0.001 for all). NDVI showed similar results, but also indicated the importance of rainfall timing on overall biomass production between years. Community composition data showed certain species, of both native and exotic identities, segregating by treatment. These results indicate that exotic species are more sensitive to rainfall, and that increased rainfall may promote greater carbon storage in annual dominated communities when compared to shrub dominated communities in high rainfall years, but with drought, this

  10. Scenarios for Ecosystem Services: An Overview

    Directory of Open Access Journals (Sweden)

    Stephen R. Carpenter

    2006-06-01

    Full Text Available The Millennium Ecosystem Assessment (MA scenarios address changes in ecosystem services and their implications for human well-being. Ecological changes pose special challenges for long-term thinking, because of the possibility of regime shifts that occur rapidly yet alter the availability of ecosystem services for generations. Moreover, ecological feedbacks can intensify human modification of ecosystems, creating a spiral of poverty and ecosystem degradation. Such complex dynamics were evaluated by a mixture of qualitative and quantitative analyses in the MA scenarios. Collectively, the scenarios explore problems such as the connections of poverty reduction and ecosystem services, and trade-offs among ecosystem services. Several promising approaches are considered by the scenarios, including uses of biodiversity to build resilience of ecosystem services, actively adaptive management, and green technology. Although the scenarios do not prescribe an optimal path, they illuminate the consequences of different policies toward ecosystem services.

  11. Socio-ecosystems and urban habitats

    Science.gov (United States)

    Margarita V. Alario

    2007-01-01

    The Millennium Ecosystem Assessment (MA)—a United Nations effort to assess the health of major global ecosystems—reported that over the past 50 years, humans have changed ecosystems more rapidly and extensively than in any comparable time in history. Around two thirds of the ecosystems services (anything from fresh water to air) are being degraded or used unsustainably...

  12. Human sepsis-associated Escherichia coli (SEPEC) is able to adhere to and invade kidney epithelial cells in culture

    Energy Technology Data Exchange (ETDEWEB)

    Conceição, R.A. [Departamento de Genética, Evolução e Bioagentes, Universidade Estadual de Campinas, Campinas, SP (Brazil); Ludovico, M.S. [Departamento de Microbiologia, Universidade Estadual de Londrina, Londrina, PR (Brazil); Andrade, C.G.T.J. [Departamento de Biologia Geral, Universidade Estadual de Londrina, Londrina, PR (Brazil); Yano, T. [Departamento de Genética, Evolução e Bioagentes, Universidade Estadual de Campinas, Campinas, SP (Brazil)

    2012-04-13

    The adhesins of extraintestinal pathogenic Escherichia coli are essential for mediating direct interactions between the microbes and the host cell surfaces that they infect. Using fluorescence microscopy and gentamycin protection assays, we observed that 49 sepsis-associated E. coli (SEPEC) strains isolated from human adults adhered to and invaded Vero cells in the presence of D-mannose (100%). In addition, bacteria concentrations of approximately 2 × 10{sup 7} CFU/mL were recovered from Vero cells following an invasion assay. Furthermore, PCR analysis of adhesin genes showed that 98.0% of these SEPEC strains tested positive for fimH, 69.4% for flu, 53.1% for csgA, 38.8% for mat, and 32.7% for iha. Analysis of the invasin genes showed that 16.3% of the SEPEC strains were positive for tia, 12.3% for gimB, and 10.2% for ibeA. Therefore, these data suggest that SEPEC adhesion to cell surfaces occurs through non-fimH mechanisms. Scanning electron microscopy showed the formation of microcolonies on the Vero cell surface. SEPEC invasiveness was also confirmed by the presence of intracellular bacteria, and ultrastructural analysis using electron transmission microscopy revealed bacteria inside the Vero cells. Taken together, these results demonstrate that these SEPEC strains had the ability to adhere to and invade Vero cells. Moreover, these data support the theory that renal cells may be the predominant pathway through which SEPEC enters human blood vessels.

  13. Native and exotic earthworms affect orchid seed loss

    OpenAIRE

    McCormick, Melissa K.; Parker, Kenneth L.; Szlavecz, Katalin; Whigham, Dennis F.

    2013-01-01

    Non-native earthworms have invaded ecosystems around the world but have recently received increased attention as they invaded previously earthworm-free habitats in northern North America. Earthworms can affect plants by ingesting seeds and burying them in the soil. These effects can be negative or positive but are expected to become increasingly negative with decreasing seed size. Orchids have some of the smallest seeds of any plants, so we hypothesized that earthworm consumption of seeds wou...

  14. Defining Ecosystem Assets for Natural Capital Accounting.

    Science.gov (United States)

    Hein, Lars; Bagstad, Ken; Edens, Bram; Obst, Carl; de Jong, Rixt; Lesschen, Jan Peter

    2016-01-01

    In natural capital accounting, ecosystems are assets that provide ecosystem services to people. Assets can be measured using both physical and monetary units. In the international System of Environmental-Economic Accounting, ecosystem assets are generally valued on the basis of the net present value of the expected flow of ecosystem services. In this paper we argue that several additional conceptualisations of ecosystem assets are needed to understand ecosystems as assets, in support of ecosystem assessments, ecosystem accounting and ecosystem management. In particular, we define ecosystems' capacity and capability to supply ecosystem services, as well as the potential supply of ecosystem services. Capacity relates to sustainable use levels of multiple ecosystem services, capability involves prioritising the use of one ecosystem service over a basket of services, and potential supply considers the ability of ecosystems to generate services regardless of demand for these services. We ground our definitions in the ecosystem services and accounting literature, and illustrate and compare the concepts of flow, capacity, capability, and potential supply with a range of conceptual and real-world examples drawn from case studies in Europe and North America. Our paper contributes to the development of measurement frameworks for natural capital to support environmental accounting and other assessment frameworks.

  15. Transpirational water loss in invaded and restored semiarid riparian forests

    Science.gov (United States)

    Georgianne W. Moore; M. Keith Owens

    2011-01-01

    The invasive tree, Tamarix sp., was introduced to the United States in the 1800s to stabilize stream banks. The riparian ecosystem adjacent to the middle Rio Grande River in central NewMexico consists of mature cottonwood (Populus fremontii ) gallery forests with a dense Tamarix understory. We hypothesized that Populus would compensate for reduced competition by...

  16. Ensemble ecosystem modeling for predicting ecosystem response to predator reintroduction.

    Science.gov (United States)

    Baker, Christopher M; Gordon, Ascelin; Bode, Michael

    2017-04-01

    Introducing a new or extirpated species to an ecosystem is risky, and managers need quantitative methods that can predict the consequences for the recipient ecosystem. Proponents of keystone predator reintroductions commonly argue that the presence of the predator will restore ecosystem function, but this has not always been the case, and mathematical modeling has an important role to play in predicting how reintroductions will likely play out. We devised an ensemble modeling method that integrates species interaction networks and dynamic community simulations and used it to describe the range of plausible consequences of 2 keystone-predator reintroductions: wolves (Canis lupus) to Yellowstone National Park and dingoes (Canis dingo) to a national park in Australia. Although previous methods for predicting ecosystem responses to such interventions focused on predicting changes around a given equilibrium, we used Lotka-Volterra equations to predict changing abundances through time. We applied our method to interaction networks for wolves in Yellowstone National Park and for dingoes in Australia. Our model replicated the observed dynamics in Yellowstone National Park and produced a larger range of potential outcomes for the dingo network. However, we also found that changes in small vertebrates or invertebrates gave a good indication about the potential future state of the system. Our method allowed us to predict when the systems were far from equilibrium. Our results showed that the method can also be used to predict which species may increase or decrease following a reintroduction and can identify species that are important to monitor (i.e., species whose changes in abundance give extra insight into broad changes in the system). Ensemble ecosystem modeling can also be applied to assess the ecosystem-wide implications of other types of interventions including assisted migration, biocontrol, and invasive species eradication. © 2016 Society for Conservation Biology.

  17. Analyzing, Modelling, and Designing Software Ecosystems

    DEFF Research Database (Denmark)

    Manikas, Konstantinos

    as the software development and distribution by a set of actors dependent on each other and the ecosystem. We commence on the hypothesis that the establishment of a software ecosystem on the telemedicine services of Denmark would address these issues and investigate how a software ecosystem can foster...... the development, implementation, and use of telemedicine services. We initially expand the theory of software ecosystems by contributing to the definition and understanding of software ecosystems, providing means of analyzing existing and designing new ecosystems, and defining and measuring the qualities...... of software ecosystems. We use these contributions to design a software ecosystem in the telemedicine services of Denmark with (i) a common platform that supports and promotes development from different actors, (ii) high software interaction, (iii) strong social network of actors, (iv) robust business...

  18. Review of Ecosystem Level Impacts of Emerald Ash Borer on Black Ash Wetlands: What Does the Future Hold?

    Directory of Open Access Journals (Sweden)

    Randall K. Kolka

    2018-04-01

    Full Text Available The emerald ash borer (EAB is rapidly spreading throughout eastern North America and devastating ecosystems where ash is a component tree. This rapid and sustained loss of ash trees has already resulted in ecological impacts on both terrestrial and aquatic ecosystems and is projected to be even more severe as EAB invades black ash-dominated wetlands of the western Great Lakes region. Using two companion studies that are simulating short- and long-term EAB infestations and what is known from the literature, we synthesize our current limited understanding and predict anticipated future impacts of EAB on black ash wetlands. A key response to the die-back of mature black ash will be higher water tables and the potential for flooding and resulting changes to both the vegetation and animal communities. Although seedling planting studies have shown some possible replacement species, little is known about how the removal of black ash from the canopy will affect non-ash species growth and regeneration. Because black ash litter is relatively high in nitrogen, it is expected that there will be important changes in nutrient and carbon cycling and subsequent rates of productivity and decomposition. Changes in hydrology and nutrient and carbon cycling will have cascading effects on the biological community which have been scarcely studied. Research to address these important gaps is currently underway and should lead to alternatives to mitigate the effects of EAB on black ash wetland forests and develop management options pre- and post-EAB invasion.

  19. Global W`o'rming and Darwin Revisited: Quantifying Soil Mixing Rates by Non-native Earthworms in Fennoscandian Boreal and Arctic Ecosystems

    Science.gov (United States)

    Wackett, A. A.; Yoo, K.; Cameron, E. K.; Olid, C.; Klaminder, J.

    2017-12-01

    Fennoscandian boreal and arctic ecosystems represent some of the most pristine environments in Europe and store sizeable quantities of soil carbon. Both ecosystems may have evolved without native earthworms since the last glaciation, but are now increasingly subject to arrivals of novel geoengineering earthworm species due to human activities. As a result, invaded areas are devoid of the typical thick organic horizon present in earthworm free forest soils and instead contain carbon-rich mineral (A-horizon) soils at the surface. How rapidly this transition occurs and how it affects the fate of soil organic carbon (SOC) pools is not well known. In this study, we quantify the rates at which earthworm-mediated mixing of forest soils proceeds in these formerly glaciated landscapes. We infer soil mass fluxes using the vertical distribution of 210Pb in soils from Fennoscandia (N=4) and North America (N=1) and quantify annual mixing velocities as well as vertical fluxes of organic and mineral matter throughout the upper soil profiles. Across the sites, mixing velocities generally increase with increasing earthworm biomass and functional group diversity, and our annual mixing rates closely align with those predicted by Darwin for earthworm-engineered ecosystems in the UK 130 years earlier. Reduction of the O-horizon is concomitant with a decrease in surface SOC contents. However, we observe minimal changes to SOC inventories with earthworm invasion across the sites, reflecting the upward translocation of mineral soil and accompanying increase in soil bulk densities. Thus, the reduction or depletion of organic horizon by exotic earthworms does not necessarily involve loss of SOC via earthworm-accelerated decomposition, but is rather compensated for by physical mixing of organic matter and minerals, which may facilitate stabilizing organo-mineral interactions. This work constitutes an important step to elucidate how non-native earthworms impact SOC inventories and potentially

  20. Appropriate experimental ecosystem warming methods by ecosystem, objective, and practicality

    Science.gov (United States)

    E.L. Aronson; S.G. McNulty

    2009-01-01

    The temperature of the Earth is rising, and is highly likely to continue to do so for the foreseeable future. The study of the effects of sustained heating on the ecosystems of the world is necessary so that wemight predict and respond to coming changes on both large and small spatial scales. To this end, ecosystem warming studies have...

  1. Defining Ecosystem Assets for Natural Capital Accounting

    Science.gov (United States)

    Hein, Lars; Bagstad, Ken; Edens, Bram; Obst, Carl; de Jong, Rixt; Lesschen, Jan Peter

    2016-01-01

    In natural capital accounting, ecosystems are assets that provide ecosystem services to people. Assets can be measured using both physical and monetary units. In the international System of Environmental-Economic Accounting, ecosystem assets are generally valued on the basis of the net present value of the expected flow of ecosystem services. In this paper we argue that several additional conceptualisations of ecosystem assets are needed to understand ecosystems as assets, in support of ecosystem assessments, ecosystem accounting and ecosystem management. In particular, we define ecosystems’ capacity and capability to supply ecosystem services, as well as the potential supply of ecosystem services. Capacity relates to sustainable use levels of multiple ecosystem services, capability involves prioritising the use of one ecosystem service over a basket of services, and potential supply considers the ability of ecosystems to generate services regardless of demand for these services. We ground our definitions in the ecosystem services and accounting literature, and illustrate and compare the concepts of flow, capacity, capability, and potential supply with a range of conceptual and real-world examples drawn from case studies in Europe and North America. Our paper contributes to the development of measurement frameworks for natural capital to support environmental accounting and other assessment frameworks. PMID:27828969

  2. Defining ecosystem assets for natural capital accounting

    Science.gov (United States)

    Hein, Lars; Bagstad, Kenneth J.; Edens, Bram; Obst, Carl; de Jong, Rixt; Lesschen, Jan Peter

    2016-01-01

    In natural capital accounting, ecosystems are assets that provide ecosystem services to people. Assets can be measured using both physical and monetary units. In the international System of Environmental-Economic Accounting, ecosystem assets are generally valued on the basis of the net present value of the expected flow of ecosystem services. In this paper we argue that several additional conceptualisations of ecosystem assets are needed to understand ecosystems as assets, in support of ecosystem assessments, ecosystem accounting and ecosystem management. In particular, we define ecosystems’ capacity and capability to supply ecosystem services, as well as the potential supply of ecosystem services. Capacity relates to sustainable use levels of multiple ecosystem services, capability involves prioritising the use of one ecosystem service over a basket of services, and potential supply considers the ability of ecosystems to generate services regardless of demand for these services. We ground our definitions in the ecosystem services and accounting literature, and illustrate and compare the concepts of flow, capacity, capability, and potential supply with a range of conceptual and real-world examples drawn from case studies in Europe and North America. Our paper contributes to the development of measurement frameworks for natural capital to support environmental accounting and other assessment frameworks.

  3. The Economics of Ecosystems: Efficiency, Sustainability and Equity in Ecosystem Management

    NARCIS (Netherlands)

    Hein, L.G.

    2010-01-01

    The Economics of Ecosystems demonstrates how the concepts of economic efficiency, sustainability and equity can be applied in ecosystem management. The book presents an overview of these three key concepts, a framework for their analysis and modelling and three case studies. Specific attention is

  4. A Size-based Ecosystem Model

    DEFF Research Database (Denmark)

    Ravn-Jonsen, Lars

     Ecosystem Management requires models that can link the ecosystem level to the operation level. This link can be created by an ecosystem production model. Because the function of the individual fish in the marine ecosystem, seen in trophic context, is closely related to its size, the model groups...... fish according to size. The model summarises individual predation events into ecosystem level properties, and thereby uses the law of conversation of mass as a framework. This paper provides the background, the conceptual model, basic assumptions, integration of fishing activities, mathematical...... the predator--prey interaction, (ii) mass balance in the predator--prey allocation, and (iii) mortality and somatic growth as a consequence of the predator--prey allocation. By incorporating additional assumptions, the model can be extended to other dimensions of the ecosystem, for example, space or species...

  5. 76 FR 75858 - Endangered and Threatened Wildlife and Plants; 6-Month Extension of Final Determination for the...

    Science.gov (United States)

    2011-12-05

    ... of Final Determination for the Proposed Listing of the Dunes Sagebrush Lizard as Endangered AGENCY... of whether to list the dunes sagebrush lizard (Sceloporus arenicolus) (lizard) as endangered and... published a proposed rule (75 FR 77801) to list the dunes sagebrush lizard, a lizard known from southeastern...

  6. Evaluation of zebra mussels (Dreissena polymorpha) as biomonitors of mercury contamination in aquatic ecosystems.

    Science.gov (United States)

    Blackwell, Bradley D; Driscoll, Charles T; Spada, Michael E; Todorova, Svetoslava G; Montesdeoca, Mario R

    2013-03-01

    Zebra mussels have invaded many lakes in the United States and could be a useful tool for monitoring responses of aquatic biota to changes in mercury loading. The goal of the present study was to evaluate zebra mussels for use as a biomonitor of mercury contamination by comparing zebra mussel mercury concentrations between a lake with only indirect atmospheric mercury contamination (Otisco Lake, NY, USA) and a lake that was directly contaminated by mercury discharges (Onondaga Lake, NY, USA). Zebra mussels were sampled in both the spring and fall of 2004 and 2005. Total mercury (THg) concentrations in zebra mussels were approximately seven times greater in Onondaga Lake than in Otisco Lake, and water column mercury concentrations differed by an order of magnitude between the two lakes. Seasonal differences resulted in significantly higher zebra mussel THg concentrations during the fall for both lakes. There was also significant variation among different sampling sites in Onondaga Lake. Mussel methylmercury concentrations averaged 53% of THg concentrations but were highly variable. Strong relationships between water column THg and zebra mussel THg suggest that zebra mussels are a good indicator of aquatic mercury concentrations and could be used as an effective biomonitor of mercury contamination in aquatic ecosystems. Copyright © 2013 SETAC.

  7. Invasion of yellow crazy ant Anoplolepis gracilipes in a Seychelles UNESCO palm forest

    Directory of Open Access Journals (Sweden)

    Christopher Kaiser-Bunbury

    2014-06-01

    Full Text Available The mature palm forest of the Vallée de Mai, a UNESCO World Heritage Site, on the Seychelles island of Praslin, is a unique ecosystem containing many endemic species, including the iconic coco de mer palm Lodoicea maldivica. In 2009, the invasive yellow crazy ant Anoplolepis gracilipes was recorded for the first time within the palm forest, raising concern about its potential impacts on the endemic fauna. This research aimed: (1 to assess the current distribution and spread of A. gracilipes within the palm forest; (2 to identify environmental variables that are linked to A. gracilipes distribution; and (3 to compare endemic species richness and abundance in A. gracilipes invaded and uninvaded areas. Anoplolepis gracilipes was confined to the north-east of the site and remained almost stationary between April 2010 and December 2012, with isolated outbreaks into the forest. Infested areas had significantly higher temperature and humidity and lower canopy cover. Abundance and species richness of the endemic arboreal fauna were lower in the A. gracilipes invaded area. Molluscs were absent from the invaded area. The current restricted distribution of A. gracilipes in this ecosystem, combined with lower abundance of endemic fauna in the invaded area, highlight the need for further research to assess control measures and the possible role of biotic resistance to the invasion of the palm forest by A. gracilipes.

  8. Management Strategy Evaluation Applied to Coral Reef Ecosystems in Support of Ecosystem-Based Management.

    Directory of Open Access Journals (Sweden)

    Mariska Weijerman

    Full Text Available Ecosystem modelling is increasingly used to explore ecosystem-level effects of changing environmental conditions and management actions. For coral reefs there has been increasing interest in recent decades in the use of ecosystem models for evaluating the effects of fishing and the efficacy of marine protected areas. However, ecosystem models that integrate physical forcings, biogeochemical and ecological dynamics, and human induced perturbations are still underdeveloped. We applied an ecosystem model (Atlantis to the coral reef ecosystem of Guam using a suite of management scenarios prioritized in consultation with local resource managers to review the effects of each scenario on performance measures related to the ecosystem, the reef-fish fishery (e.g., fish landings and coral habitat. Comparing tradeoffs across the selected scenarios showed that each scenario performed best for at least one of the selected performance indicators. The integrated 'full regulation' scenario outperformed other scenarios with four out of the six performance metrics at the cost of reef-fish landings. This model application quantifies the socio-ecological costs and benefits of alternative management scenarios. When the effects of climate change were taken into account, several scenarios performed equally well, but none prevented a collapse in coral biomass over the next few decades assuming a business-as-usual greenhouse gas emissions scenario.

  9. Management Strategy Evaluation Applied to Coral Reef Ecosystems in Support of Ecosystem-Based Management.

    Science.gov (United States)

    Weijerman, Mariska; Fulton, Elizabeth A; Brainard, Russell E

    2016-01-01

    Ecosystem modelling is increasingly used to explore ecosystem-level effects of changing environmental conditions and management actions. For coral reefs there has been increasing interest in recent decades in the use of ecosystem models for evaluating the effects of fishing and the efficacy of marine protected areas. However, ecosystem models that integrate physical forcings, biogeochemical and ecological dynamics, and human induced perturbations are still underdeveloped. We applied an ecosystem model (Atlantis) to the coral reef ecosystem of Guam using a suite of management scenarios prioritized in consultation with local resource managers to review the effects of each scenario on performance measures related to the ecosystem, the reef-fish fishery (e.g., fish landings) and coral habitat. Comparing tradeoffs across the selected scenarios showed that each scenario performed best for at least one of the selected performance indicators. The integrated 'full regulation' scenario outperformed other scenarios with four out of the six performance metrics at the cost of reef-fish landings. This model application quantifies the socio-ecological costs and benefits of alternative management scenarios. When the effects of climate change were taken into account, several scenarios performed equally well, but none prevented a collapse in coral biomass over the next few decades assuming a business-as-usual greenhouse gas emissions scenario.

  10. FEGS at the inflection point: How linking Ecosystem Services to Human Benefit improves management of coastal ecosystems.

    Science.gov (United States)

    Final ecosystem goods and services (FEGS) are the connection between the ecosystem resources and human stakeholders that benefit from natural capital. The FEGS concept is an extension of the ecosystem services (ES) concept (e.g., Millennium Ecosystem Assessment) and results from...

  11. Characterizing the Danish telemedicine ecosystem

    DEFF Research Database (Denmark)

    Manikas, Konstantinos; Hansen, Klaus Marius

    2013-01-01

    and interoperability issues, silo solutions, and lack of guidelines and standards. In this paper, we characterise the ecosystem evolved around the telemedicine services in Denmark and study the actors involved in this ecosystem. We establish a method for this study, where we define two actor roles and ways...... of characterizing actor contributions, and apply the method to the largest healthcare region of Denmark. Our findings reveal an ecosystem that is relatively closed to new actors, where the actors tend to be related to single telemedicine applications, the applications have low connectivity, and the most influential...... actors of the ecosystem can be characterised as both being beneficial and inhibitory to the ecosystem prosperity....

  12. Vegetative Regeneration Capacities of Five Ornamental Plant Invaders After Shredding

    Science.gov (United States)

    Monty, Arnaud; Eugène, Marie; Mahy, Grégory

    2015-02-01

    Vegetation management often involves shredding to dispose of cut plant material or to destroy the vegetation itself. In the case of invasive plants, this can represent an environmental risk if the shredded material exhibits vegetative regeneration capacities. We tested the effect of shredding on aboveground and below-ground vegetative material of five ornamental widespread invaders in Western Europe that are likely to be managed by cutting and shredding techniques: Buddleja davidii (butterfly bush, Scrophulariaceae), Fallopia japonica (Japanese knotweed, Polygonaceae), Spiraea × billardii Hérincq (Billard's bridewort, Rosaceae), Solidago gigantea (giant goldenrod, Asteraceae), and Rhus typhina L. (staghorn sumac, Anacardiaceae). We looked at signs of vegetative regeneration and biomass production, and analyzed the data with respect to the season of plant cutting (spring vs summer), the type of plant material (aboveground vs below-ground), and the shredding treatment (shredded vs control). All species were capable of vegetative regeneration, especially the below-ground material. We found differences among species, but the regeneration potential was generally still present after shredding despite a reduction of growth rates. Although it should not be excluded in all cases (e.g., destruction of giant goldenrod and staghorn sumac aboveground material), the use of a shredder to destroy woody alien plant material cannot be considered as a general management option without significant environmental risk.

  13. Merging Platform Ecosystems in Technology Acquisitions

    DEFF Research Database (Denmark)

    Dowie, Jamie; Henningsson, Stefan; Kude, Thomas

    2017-01-01

    of the merging companies. Given the increasing importance of platforms and value co-creation with third-party providers for companies making technology acquisitions, we complement existing literature by reframing the analysis of technology acquisitions to include the merger of the broader partner ecosystems....... Specifically, we draw on theories of ecosystem governance to analyze how ecosystem tensions unfolded during the ecosystem merger and how the acquirer governed these tensions in SAP SE’s acquisition of the e-commerce provider Hybris AG. Our findings suggest that the governance of ecosystem tensions...... is an important aspect of managing technology acquisitions. We identify the pre-acquisition relation between the acquired company’s ecosystem partners and the acquirer as an important context factor for explaining how a partner company is exposed to the ecosystem tensions during the merger....

  14. Ecosystem quality in LCIA

    DEFF Research Database (Denmark)

    Woods, John S.; Damiani, Mattia; Fantke, Peter

    2017-01-01

    Purpose: Life cycle impact assessment (LCIA) results are used to assess potential environmental impacts of different products and services. As part of the UNEP-SETAC life cycle initiative flagship project that aims to harmonize indicators of potential environmental impacts, we provide a consensus...... viewpoint and recommendations for future developments in LCIA related to the ecosystem quality area of protection (AoP). Through our recommendations, we aim to encourage LCIA developments that improve the usefulness and global acceptability of LCIA results. Methods: We analyze current ecosystem quality...... metrics and provide recommendations to the LCIA research community for achieving further developments towards comparable and more ecologically relevant metrics addressing ecosystem quality. Results and discussion: We recommend that LCIA development for ecosystem quality should tend towards species...

  15. The Coevolution of Digital Ecosystems

    Science.gov (United States)

    SungYong, Um

    2016-01-01

    Digital ecosystems are one of the most important strategic issues in the current digital economy. Digital ecosystems are dynamic and generative. They evolve as new firms join and as heterogeneous systems are integrated into other systems. These features digital ecosystems determine economic and technological success in the competition among…

  16. Linking Ecosystem Services Benefit Transfer Databases and Ecosystem Services Production Function Libraries

    Science.gov (United States)

    The quantification or estimation of the economic and non-economic values of ecosystem services can be done from a number of distinct approaches. For example, practitioners may use ecosystem services production function models (ESPFMs) for a particular location, or alternatively, ...

  17. Predicting Ecosystem Alliances Using Landscape Theory

    Directory of Open Access Journals (Sweden)

    Shruti Satsangi

    2012-08-01

    Full Text Available Previous articles in the TIM Review have covered various aspects of the concept of business ecosystems, from the types of ecosystems to keystone strategy, to different member roles and value co-creation. While there is no dearth of suggested best practices that organizations should follow as ecosystem members, it can be difficult to apply these insights into actionable steps for them to take. This is especially true when the ecosystem members already have a prior history of cooperation or competition with each other, as opposed to where a new ecosystem is created. Landscape theory, a political science approach to predicting coalition formation and strategic alliances, can be a useful complement to ecosystems studies by providing a tool to evaluate the best possible alliance options for an organization, given information about itself and the other companies in the system. As shown in the case study of mobile device manufacturers choosing platform providers in the mobile ecosystem, this tool is highly flexible and customizable, with more data providing a more accurate view of the alliances in the ecosystem. At the same time, with even basic parameters, companies can glean significant information about which coalitions will best serve their interest and overall standing within the ecosystem. This article shows the synergies between landscape theory and an ecosystems approach and offers a practical, actionable way in which to analyze individual member benefits.

  18. Value of ecosystem hydropower service and its impact on the payment for ecosystem services.

    Science.gov (United States)

    Fu, B; Wang, Y K; Xu, P; Yan, K; Li, M

    2014-02-15

    Hydropower is an important service provided by ecosystems. We surveyed all the hydropower plants in the Zagunao River Basin, Southwest China. Then, we assessed the hydropower service by using the InVEST (The Integrated Value and Tradeoff of Ecosystem Service Tools) model. Finally, we discussed the impact on ecological compensation. The results showed that: 1) hydropower service value of ecosystems in the Zagunao River Basin is 216.29 Euro/hm(2) on the average, of which the high-value area with more than 475.65 Euro/hm(2) is about 750.37 km(2), accounting for 16.12% of the whole watershed, but it provides 53.47% of the whole watershed service value; 2) ecosystem is an ecological reservoir with a great regulation capacity. Dams cannot completely replace the reservoir water conservation function of ecosystems, and has high economic and environmental costs that must be paid as well. Compensation for water conservation services should become an important basis for ecological compensation of hydropower development. 3) In the current PES cases, the standard of compensation is generally low. Cascade development makes the value of upstream ecosystem services become more prominent, reflecting the differential rent value, and the value of ecosystem services should be based on the distribution of differentiated ecological compensation. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Ecosystem services capacity across heterogeneous forest types: understanding the interactions and suggesting pathways for sustaining multiple ecosystem services.

    Science.gov (United States)

    Alamgir, Mohammed; Turton, Stephen M; Macgregor, Colin J; Pert, Petina L

    2016-10-01

    As ecosystem services supply from tropical forests is declining due to deforestation and forest degradation, much effort is essential to sustain ecosystem services supply from tropical forested landscapes, because tropical forests provide the largest flow of multiple ecosystem services among the terrestrial ecosystems. In order to sustain multiple ecosystem services, understanding ecosystem services capacity across heterogeneous forest types and identifying certain ecosystem services that could be managed to leverage positive effects across the wider bundle of ecosystem services are required. We sampled three forest types, tropical rainforests, sclerophyll forests, and rehabilitated plantation forests, over an area of 32,000m(2) from Wet Tropics bioregion, Australia, aiming to compare supply and evaluate interactions and patterns of eight ecosystem services (global climate regulation, air quality regulation, erosion regulation, nutrient regulation, cyclone protection, habitat provision, energy provision, and timber provision). On average, multiple ecosystem services were highest in the rainforests, lowest in sclerophyll forests, and intermediate in rehabilitated plantation forests. However, a wide variation was apparent among the plots across the three forest types. Global climate regulation service had a synergistic impact on the supply of multiple ecosystem services, while nutrient regulation service was found to have a trade-off impact. Considering multiple ecosystem services, most of the rehabilitated plantation forest plots shared the same ordination space with rainforest plots in the ordination analysis, indicating that rehabilitated plantation forests may supply certain ecosystem services nearly equivalent to rainforests. Two synergy groups and one trade-off group were identified. Apart from conserving rainforests and sclerophyll forests, our findings suggest two additional integrated pathways to sustain the supply of multiple ecosystem services from a

  20. An Indicator for ecosystem externalities in fishing

    DEFF Research Database (Denmark)

    Ravn-Jonsen, Lars; Andersen, Ken Haste; Vestergaard, Niels

    Ecosystem externalities arise when one use of an ecosystem affects its other uses through the production functions of the ecosystem.We use simulations from a size-spectrum ecosystem model to investigate the ecosystem externality created by fishing of multiple species. The model is based upon...

  1. Promoting Transfer of Ecosystems Concepts

    Science.gov (United States)

    Yu, Yawen; Hmelo-Silver, Cindy E.; Jordan, Rebecca; Eberbach, Catherine; Sinha, Suparna

    2016-01-01

    This study examines to what extent students transferred their knowledge from a familiar aquatic ecosystem to an unfamiliar rainforest ecosystem after participating in a technology-rich inquiry curriculum. We coded students' drawings for components of important ecosystems concepts at pre- and posttest. Our analysis examined the extent to which each…

  2. From COS ecosystem fluxes to GPP: integrating soil, branch and ecosystem fluxes.

    Science.gov (United States)

    Kooijmans, L.; Maseyk, K. S.; Vesala, T.; Mammarella, I.; Baker, I. T.; Seibt, U.; Sun, W.; Aalto, J.; Franchin, A.; Kolari, P.; Keskinen, H.; Levula, J.; Chen, H.

    2016-12-01

    The close coupling of Carbonyl Sulfide (COS) and CO2 due to a similar uptake pathway into plant stomata makes COS a promising new tracer that can potentially be used to partition the Net Ecosystem Exchange into gross primary production (GPP) and respiration. Although ecosystem-scale measurements have been made at several sites, the contribution of different ecosystem components to the total COS budget is often unknown. Besides that, the average Leaf Relative Uptake (LRU) ratio needs to be better determined to accurately translate COS ecosystem fluxes into GPP estimates when the simple linear correlation between GPP estimates and COS plant uptake is used. We performed two campaigns in the summer of 2015 and 2016 at the SMEAR II site in Hyytiälä, Finland to provide better constrained COS flux data for boreal forests. A combination of COS measurements were made during both years, i.e. atmospheric profile concentrations up to 125 m, eddy-covariance fluxes and soil chamber fluxes. In addition to these, branch chamber measurements were done in 2016 in an attempt to observe the LRU throughout the whole season. The LRU ratio shows an exponential correlation with photosynthetic active radiation (PAR) but is constant for PAR levels above 500 µmol m-2 s-1. Mid-day LRU values are 1.0 (aspen) and 1.5 (pine). The correlation between LRU and PAR can be explained by the fact that COS is hydrolyzed with the presence of the enzyme carbonic anhydrase, and is not light dependent, whereas the photosynthetic uptake of CO2 is. We observed nighttime fluxes on the order of 25-30 % of the daily maximum COS uptake. Soils are a small sink of COS and contribute to 3 % of the total ecosystem COS flux during daytime. In a comparison between observed and simulated fluxes from the Simple Biosphere (SiB) model, the modelled COS and CO2 ecosystem fluxes are on average 40 % smaller than the observed fluxes, however, the Ecosystem Relative Uptake (ERU) ratios are identical at a value of 1.9 ± 0

  3. Coral reefs - Specialized ecosystems

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.

    This paper discusses briefly some aspects that characterize and differentiate coral reef ecosystems from other tropical marine ecosystems. A brief account on the resources that are extractable from coral reefs, their susceptibility to natural...

  4. Formation of Service Ecosystems

    DEFF Research Database (Denmark)

    Jonas, Julia M.; Sörhammar, David; Satzger, Gerhard

    – i.e. the “birth phase” (Moore, 2009) of a service ecosystem. This paper, therefore, aims to explore how the somewhat “magic” processes of service ecosystem formation that are being taken for granted actually occur. Methodology/Approach: Building on a review of core elements in the definitions...... for Harvard students) or value proposition (share messages, photos, videos, etc. with friends). Processes of configuring actors, resources, and value propositions are influenced by the structural embeddedness of the service ecosystem (e.g., regional infrastructure, existing networks of actors, or resource...... availability) as well as guided by the actors’ own and shared institutions (e.g., rules, norms,and beliefs).We contextualize each starting point with illustrative cases and analyze the service ecosystem configuration process: “Axoon/Trumpf” (initiated by resources), “JOSEPHS – the service manufactory...

  5. Ecosystem overfishing in the ocean.

    Science.gov (United States)

    Coll, Marta; Libralato, Simone; Tudela, Sergi; Palomera, Isabel; Pranovi, Fabio

    2008-01-01

    Fisheries catches represent a net export of mass and energy that can no longer be used by trophic levels higher than those fished. Thus, exploitation implies a depletion of secondary production of higher trophic levels (here the production of mass and energy by herbivores and carnivores in the ecosystem) due to the removal of prey. The depletion of secondary production due to the export of biomass and energy through catches was recently formulated as a proxy for evaluating the ecosystem impacts of fishing-i.e., the level of ecosystem overfishing. Here we evaluate the historical and current risk of ecosystem overfishing at a global scale by quantifying the depletion of secondary production using the best available fisheries and ecological data (i.e., catch and primary production). Our results highlight an increasing trend in the number of unsustainable fisheries (i.e., an increase in the risk of ecosystem overfishing) from the 1950s to the 2000s, and illustrate the worldwide geographic expansion of overfishing. These results enable to assess when and where fishing became unsustainable at the ecosystem level. At present, total catch per capita from Large Marine Ecosystems is at least twice the value estimated to ensure fishing at moderate sustainable levels.

  6. Software ecosystems – a systematic literature review

    DEFF Research Database (Denmark)

    Manikas, Konstantinos; Hansen, Klaus Marius

    2013-01-01

    A software ecosystem is the interaction of a set of actors on top of a common technological platform that results in a number of software solutions or services. Arguably, software ecosystems are gaining importance with the advent of, e.g., the Google Android, Apache, and Salesforce.com ecosystems....... However, there exists no systematic overview of the research done on software ecosystems from a software engineering perspective. We performed a systematic literature review of software ecosystem research, analyzing 90 papers on the subject taken from a gross collection of 420. Our main conclusions...... are that while research on software ecosystems is increasing (a) there is little consensus on what constitutes a software ecosystem, (b) few analytical models of software ecosystems exist, and (c) little research is done in the context of real-world ecosystems. This work provides an overview of the field, while...

  7. 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.

  8. 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.

  9. Ecosystem services provided by bats.

    Science.gov (United States)

    Kunz, Thomas H; Braun de Torrez, Elizabeth; Bauer, Dana; Lobova, Tatyana; Fleming, Theodore H

    2011-03-01

    Ecosystem services are the benefits obtained from the environment that increase human well-being. Economic valuation is conducted by measuring the human welfare gains or losses that result from changes in the provision of ecosystem services. Bats have long been postulated to play important roles in arthropod suppression, seed dispersal, and pollination; however, only recently have these ecosystem services begun to be thoroughly evaluated. Here, we review the available literature on the ecological and economic impact of ecosystem services provided by bats. We describe dietary preferences, foraging behaviors, adaptations, and phylogenetic histories of insectivorous, frugivorous, and nectarivorous bats worldwide in the context of their respective ecosystem services. For each trophic ensemble, we discuss the consequences of these ecological interactions on both natural and agricultural systems. Throughout this review, we highlight the research needed to fully determine the ecosystem services in question. Finally, we provide a comprehensive overview of economic valuation of ecosystem services. Unfortunately, few studies estimating the economic value of ecosystem services provided by bats have been conducted to date; however, we outline a framework that could be used in future studies to more fully address this question. Consumptive goods provided by bats, such as food and guano, are often exchanged in markets where the market price indicates an economic value. Nonmarket valuation methods can be used to estimate the economic value of nonconsumptive services, including inputs to agricultural production and recreational activities. Information on the ecological and economic value of ecosystem services provided by bats can be used to inform decisions regarding where and when to protect or restore bat populations and associated habitats, as well as to improve public perception of bats. © 2011 New York Academy of Sciences.

  10. The use of steady state neutron flux measurement to determine the size of an invaded region following fluid injection

    International Nuclear Information System (INIS)

    Parsons, R.J.

    1983-01-01

    By using a combination of Monte-Carlo and diffusion theory techniques, the behaviour of the thermal neutron flux during fluid injection is studied. It is shown that the change in neutron flux induced by the fluid injection, is equal to the neutron flux due to a certain thermal neutron source distribution. Using this result, a method of estimating the size of an elliptical invaded region is given. This choice of region shape is not a necessity but a convenience and it is possible that the method may be generalised to include higher order shapes. (author)

  11. Phenology, growth, and fecundity as determinants of distribution in closely related nonnative taxa

    Science.gov (United States)

    Marushia, Robin G.; Brooks, Matthew L.; Holt, Jodie S.

    2012-01-01

    Invasive species researchers often ask: Why do some species invade certain habitats while others do not? Ecological theories predict that taxonomically related species may invade similar habitats, but some related species exhibit contrasting invasion patterns. Brassica nigra, Brassica tournefortii, and Hirschfeldia incana are dominant, closely related nonnative species that have overlapping, but dissimilar, distributions. Brassica tournefortii is rapidly spreading in warm deserts of the southwestern United States, whereas B. nigra and H. incana are primarily limited to semiarid and mesic regions. We compared traits of B. tournefortii that might confer invasiveness in deserts with those of related species that have not invaded desert ecosystems. Brassica tournefortii, B. nigra and H. incana were compared in controlled experiments conducted outdoors in a mesic site (Riverside, CA) and a desert site (Blue Diamond, NV), and in greenhouses, over 3 yr. Desert and mesic B. tournefortii populations were also compared to determine whether locally adapted ecotypes contribute to desert invasion. Experimental variables included common garden sites and soil water availability. Response variables included emergence, growth, phenology, and reproduction. There was no evidence for B. tournefortii ecotypes, but B. tournefortii had a more rapid phenology than B. nigra or H. incana. Brassica tournefortii was less affected by site and water availability than B. nigra and H. incana, but was smaller and less fecund regardless of experimental conditions. Rapid phenology allows B. tournefortii to reproduce consistently under variable, stressful conditions such as those found in Southwestern deserts. Although more successful in milder, mesic ecosystems, B. nigra and H. incana may be limited by their ability to reproduce under desert conditions. Rapid phenology and drought response partition invasion patterns of nonnative mustards along a gradient of aridity in the southwestern United States

  12. Producer-decomposer matching in a simple model ecosystem: A network coevolutionary approach to ecosystem organization

    International Nuclear Information System (INIS)

    Higashi, Masahiko; Yamamura, Norio; Nakajima, Hisao; Abe, Takuya

    1993-01-01

    The present not is concerned with how the ecosystem maintains its energy and matter processes, and how those processes change throughout ecological and geological time, or how the constituent biota of an ecosystem maintain their life, and how ecological (species) succession and biological evolution proceed within an ecosystem. To advance further Tansky's (1976) approach to ecosystem organization, which investigated the characteristic properties of the developmental process of a model ecosystem, by applying Margalef's (1968) maximum maturity principle to derive its long term change, we seek a course for deriving the macroscopic trends along the organization process of an ecosystem as a consequence of the interactions among its biotic components and their modification of ecological traits. Using a simple ecosystem model consisting of four aggregated components (open-quotes compartmentsclose quotes) connected by nutrient flows, we investigate how a change in the value of a parameter alters the network pattern of flows and stocks, even causing a change in the value of another parameter, which in turn brings about further change in the network pattern and values of some (possible original) parameters. The continuation of this chain reaction involving feedbacks constitutes a possible mechanism for the open-quotes coevolutionclose quotes or open-quotes matchingclose quotes among flows, stocks, and parameters

  13. Response of bird community structure to habitat management in piñon-juniper woodland-sagebrush ecotones

    Science.gov (United States)

    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.

  14. Dimensions of ecosystem theory

    International Nuclear Information System (INIS)

    O'Neill, R.V.; Reichle, D.E.

    1979-01-01

    Various dimensions of ecosystem structure and behavior that seem to develop from the ubiquitous phenomena of system growth and persistence were studied. While growth and persistence attributes of ecosystems may appear to be simplistic phenomena upon which to base a comprehensive ecosystem theory, these same attributes have been fundamental to the theoretical development of other biological disciplines. These attributes were explored at a hierarchical level in a self-organizing system, and adaptive system strategies that result were analyzed. Previously developed causative relations (Reichle et al., 1975c) were examined, their theoretical implications expounded upon, and the assumptions tested with data from a variety of forest types. The conclusions are not a theory in themselves, but a state of organization of concepts contributing towards a unifying theory, along the lines promulgated by Bray (1958). The inferences drawn rely heavily upon data from forested ecosystems of the world, and have yet to be validated against data from a much more diverse range of ecosystem types. Not all of the interpretations are logically tight - there is room for other explanations, which it is hoped will provide fruitful grounds for further speculation

  15. Soil-based ecosystem services

    DEFF Research Database (Denmark)

    Ghaley, Bhim Bahadur; Porter, John Roy; Sandhu, Harpinder S.

    2014-01-01

    Among the soil-based ecosystem services (ES), nutrient cycling and carbon sequestration have direct influence on the biogeochemical cycles and greenhouse gas emissions affecting provision of other ES that support human existence. We reviewed methods to assess the two key ES by identifying...... their strengths and weaknesses and have made suggestions for using appropriate methods for better understanding of the ecosystem functions for the provision of ES. Relevant papers for the review were chosen on the basis of (i) diversity of studies on the two key ES in different ecosystems, (ii) methodologies...... applied and (iii) detailed descriptions of the trial locations in terms of vegetation, soil type, location and climatic information. We concluded that (i) elemental stoichiometrical ratios could be a potential approach to assess the health of ecosystems in terms of provision of the two ES discussed, (ii...

  16. List identifies threatened ecosystems

    Science.gov (United States)

    Showstack, Randy

    2012-09-01

    The International Union for Conservation of Nature (IUCN) announced on 9 September that it will develop a new Red List of Ecosystems that will identify which ecosystems are vulnerable or endangered. The list, which is modeled on the group's Red List of Threatened Species™, could help to guide conservation activities and influence policy processes such as the Convention on Biological Diversity, according to the group. “We will assess the status of marine, terrestrial, freshwater, and subterranean ecosystems at local, regional, and global levels,” stated Jon Paul Rodriguez, leader of IUCN's Ecosystems Red List Thematic Group. “The assessment can then form the basis for concerted implementation action so that we can manage them sustainably if their risk of collapse is low or restore them if they are threatened and then monitor their recovery.”

  17. Ecosystem services for energy security

    Energy Technology Data Exchange (ETDEWEB)

    Athanas, Andrea; McCormick, Nadine

    2010-09-15

    The world is at an energy crossroads. The changes underway will have implications for ecosystems and livelihoods. Energy security is the reliable supply of affordable energy, of which there are two dimensions; reliability and resilience. Changes in ecosystem services linked to degradation and climate change have the potential to impact both on the reliabiity of energy systems and on their resiliance. Investing in ecosystems can help safeguard energy systems, and mitigate unforeseen risks to energy security. The energy and conservation community should come together to build reliable and resilliant energy systems in ways which recognise and value supporting ecosystems.

  18. RELATIONSHIPS OF ALIEN PLANT SPECIES ABUNDANCE TO RIPARIAN VEGETATION, ENVIRONMENT, AND DISTURBANCE

    Science.gov (United States)

    Riparian ecosystems are often invaded by alien species. We evaluated vegetation, environment, and disturbance conditions and their interrelationships with alien species abundance along reaches of 29 streams in eastern Oregon, USA. Using flexible-BETA clustering, indicator species...

  19. Uncovering ecosystem service bundles through social preferences.

    Directory of Open Access Journals (Sweden)

    Berta Martín-López

    Full Text Available Ecosystem service assessments have increasingly been used to support environmental management policies, mainly based on biophysical and economic indicators. However, few studies have coped with the social-cultural dimension of ecosystem services, despite being considered a research priority. We examined how ecosystem service bundles and trade-offs emerge from diverging social preferences toward ecosystem services delivered by various types of ecosystems in Spain. We conducted 3,379 direct face-to-face questionnaires in eight different case study sites from 2007 to 2011. Overall, 90.5% of the sampled population recognized the ecosystem's capacity to deliver services. Formal studies, environmental behavior, and gender variables influenced the probability of people recognizing the ecosystem's capacity to provide services. The ecosystem services most frequently perceived by people were regulating services; of those, air purification held the greatest importance. However, statistical analysis showed that socio-cultural factors and the conservation management strategy of ecosystems (i.e., National Park, Natural Park, or a non-protected area have an effect on social preferences toward ecosystem services. Ecosystem service trade-offs and bundles were identified by analyzing social preferences through multivariate analysis (redundancy analysis and hierarchical cluster analysis. We found a clear trade-off among provisioning services (and recreational hunting versus regulating services and almost all cultural services. We identified three ecosystem service bundles associated with the conservation management strategy and the rural-urban gradient. We conclude that socio-cultural preferences toward ecosystem services can serve as a tool to identify relevant services for people, the factors underlying these social preferences, and emerging ecosystem service bundles and trade-offs.

  20. Neighbourhood-scale urban forest ecosystem classification.

    Science.gov (United States)

    Steenberg, James W N; Millward, Andrew A; Duinker, Peter N; Nowak, David J; Robinson, Pamela J

    2015-11-01

    Urban forests are now recognized as essential components of sustainable cities, but there remains uncertainty concerning how to stratify and classify urban landscapes into units of ecological significance at spatial scales appropriate for management. Ecosystem classification is an approach that entails quantifying the social and ecological processes that shape ecosystem conditions into logical and relatively homogeneous management units, making the potential for ecosystem-based decision support available to urban planners. The purpose of this study is to develop and propose a framework for urban forest ecosystem classification (UFEC). The multifactor framework integrates 12 ecosystem components that characterize the biophysical landscape, built environment, and human population. This framework is then applied at the neighbourhood scale in Toronto, Canada, using hierarchical cluster analysis. The analysis used 27 spatially-explicit variables to quantify the ecosystem components in Toronto. Twelve ecosystem classes were identified in this UFEC application. Across the ecosystem classes, tree canopy cover was positively related to economic wealth, especially income. However, education levels and homeownership were occasionally inconsistent with the expected positive relationship with canopy cover. Open green space and stocking had variable relationships with economic wealth and were more closely related to population density, building intensity, and land use. The UFEC can provide ecosystem-based information for greening initiatives, tree planting, and the maintenance of the existing canopy. Moreover, its use has the potential to inform the prioritization of limited municipal resources according to ecological conditions and to concerns of social equity in the access to nature and distribution of ecosystem service supply. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Fort Collins Science Center: Ecosystem Dynamics

    Science.gov (United States)

    Bowen, Zack

    2004-01-01

    Many challenging natural resource management issues require consideration of a web of interactions among ecosystem components. The spatial and temporal complexity of these ecosystem problems demands an interdisciplinary approach integrating biotic and abiotic processes. The goals of the Ecosystem Dynamics Branch are to provide sound science to aid federal resource managers and use long-term, place-focused research and monitoring on federal lands to advance ecosystem science.

  2. The Multifaceted Aspects of Ecosystem Integrity

    Directory of Open Access Journals (Sweden)

    Giulio A. De Leo

    1997-06-01

    Full Text Available The need to reduce human impacts on ecosystems creates pressure for adequate response, but the rush to solutions fosters the oversimplification of such notions as sustainable development and ecosystem health. Hence, it favors the tendency to ignore the complexity of natural systems. In this paper, after a brief analysis of the use and abuse of the notion of ecosystem health, we address the problem of a sound definition of ecosystem integrity, critically review the different methodological and conceptual approaches to the management of natural resources, and sketch the practical implications stemming from their implementation. We show thatthere are merits and limitations in different definitions of ecosystem integrity, for each acknowledges different aspects of ecosystem structure and functioning and reflects the subjective perspectives of humans on the value, importance, and role of biological diversity. This evaluation is based on a brief sketch of the links among biodiversity, ecosystem functioning and resilience, and a description of the problems that arise in distinguishing between natural and anthropogenic disturbance. We also emphasize the difficulty of assessing the economic value of species and habitats and the need to use adaptive management policies to deal with uncertainty and ecosystem complexity. In conclusion, while acknowledging that environmental legislation requires objective statements on ecosystem status and trends, we stress that the notion of ecological integrity is so complex that its measure cannot be expressed through a single indicator, but rather requires a set of indicators at different spatial, temporal, and hierarchical levels of ecosystem organization. Ecosystem integrity is not an absolute, monolithic concept. The existence of different sets of values regarding biological diversity and environmental risks must be explicitly accounted for and incorporated in the decision process, rather than ignored or averaged out.

  3. Towards ecosystem-based management

    NARCIS (Netherlands)

    Tam, Jamie C.; Link, Jason S.; Rossberg, Axel G.; Rogers, Stuart I.; Levin, Philip S.; Rochet, Marie-Joelle; Bundy, Alida; Belgrano, Andrea; Libralato, Simone; Tomczak, Maciej; Wolfshaar, van de K.E.; Pranovi, Fabio; Gorokhova, Elena; Large, Scott I.; Niquil, Nathalie; Greenstreet, Simon P.R.; Druon, Jean-Noel; Lesutiene, Jurate; Johansen, Marie; Preciado, Izaskun; Patricio, Joana; Palialexis, Andreas; Tett, Paul; Johansen, Geir O.; Houle, Jennifer; Rindorf, Anna

    2017-01-01

    Modern approaches to Ecosystem-Based Management and sustainable use of marine resources must account for the myriad of pressures (interspecies, human and environmental) affecting marine ecosystems. The network of feeding interactions between co-existing species and populations (food webs) are an

  4. 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).

  5. Biodiversity and Resilience of Ecosystem Functions.

    Science.gov (United States)

    Oliver, Tom H; Heard, Matthew S; Isaac, Nick J B; Roy, David B; Procter, Deborah; Eigenbrod, Felix; Freckleton, Rob; Hector, Andy; Orme, C David L; Petchey, Owen L; Proença, Vânia; Raffaelli, David; Suttle, K Blake; Mace, Georgina M; Martín-López, Berta; Woodcock, Ben A; Bullock, James M

    2015-11-01

    Accelerating rates of environmental change and the continued loss of global biodiversity threaten functions and services delivered by ecosystems. Much ecosystem monitoring and management is focused on the provision of ecosystem functions and services under current environmental conditions, yet this could lead to inappropriate management guidance and undervaluation of the importance of biodiversity. The maintenance of ecosystem functions and services under substantial predicted future environmental change (i.e., their 'resilience') is crucial. Here we identify a range of mechanisms underpinning the resilience of ecosystem functions across three ecological scales. Although potentially less important in the short term, biodiversity, encompassing variation from within species to across landscapes, may be crucial for the longer-term resilience of ecosystem functions and the services that they underpin. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. The potential distribution of invading Helicoverpa armigera in North America: is it just a matter of time?

    Directory of Open Access Journals (Sweden)

    Darren J Kriticos

    Full Text Available Helicoverpa armigera has recently invaded South and Central America, and appears to be spreading rapidly. We update a previously developed potential distribution model to highlight the global invasion threat, with emphasis on the risks to the United States. The continued range expansion of H. armigera in Central America is likely to change the invasion threat it poses to North America qualitatively, making natural dispersal from either the Caribbean islands or Mexico feasible. To characterise the threat posed by H. armigera, we collated the value of the major host crops in the United States growing within its modelled potential range, including that area where it could expand its range during favourable seasons. We found that the annual value of crops that would be exposed to H. armigera totalled approximately US$78 billion p.a., with US$843 million p.a. worth growing in climates that are optimal for the pest. Elsewhere, H. armigera has developed broad-spectrum pesticide resistance; meaning that if it invades the United States, protecting these crops from significant production impacts could be challenging. It may be cost-effective to undertake pre-emptive biosecurity activities such as slowing the spread of H. armigera throughout the Americas, improving the system for detecting H. armigera, and methods for rapid identification, especially distinguishing between H. armigera, H. zea and potential H. armigera x H. zea hybrids. Developing biological control programs, especially using inundative techniques with entomopathogens and parasitoids could slow the spread of H. armigera, and reduce selective pressure for pesticide resistance. The rapid spread of H. armigera through South America into Central America suggests that its spread into North America is a matter of time. The likely natural dispersal routes preclude aggressive incursion responses, emphasizing the value of preparatory communication with agricultural producers in areas suitable for

  7. Revisiting software ecosystems research

    DEFF Research Database (Denmark)

    Manikas, Konstantinos

    2016-01-01

    ‘Software ecosystems’ is argued to first appear as a concept more than 10 years ago and software ecosystem research started to take off in 2010. We conduct a systematic literature study, based on the most extensive literature review in the field up to date, with two primarily aims: (a) to provide...... an updated overview of the field and (b) to document evolution in the field. In total, we analyze 231 papers from 2007 until 2014 and provide an overview of the research in software ecosystems. Our analysis reveals a field that is rapidly growing both in volume and empirical focus while becoming more mature...... from evolving. We propose means for future research and the community to address them. Finally, our analysis shapes the view of the field having evolved outside the existing definitions of software ecosystems and thus propose the update of the definition of software ecosystems....

  8. Alternative states of a semiarid grassland ecosystem: implications for ecosystem services

    Science.gov (United States)

    Miller, Mark E.; Belote, R. Travis; Bowker, Matthew A.; Garman, Steven L.

    2011-01-01

    Ecosystems can shift between alternative states characterized by persistent differences in structure, function, and capacity to provide ecosystem services valued by society. We examined empirical evidence for alternative states in a semiarid grassland ecosystem where topographic complexity and contrasting management regimes have led to spatial variations in levels of livestock grazing. Using an inventory data set, we found that plots (n = 72) cluster into three groups corresponding to generalized alternative states identified in an a priori conceptual model. One cluster (biocrust) is notable for high coverage of a biological soil crust functional group in addition to vascular plants. Another (grass-bare) lacks biological crust but retains perennial grasses at levels similar to the biocrust cluster. A third (annualized-bare) is dominated by invasive annual plants. Occurrence of grass-bare and annualized-bare conditions in areas where livestock have been excluded for over 30 years demonstrates the persistence of these states. Significant differences among all three clusters were found for percent bare ground, percent total live cover, and functional group richness. Using data for vegetation structure and soil erodibility, we also found large among-cluster differences in average levels of dust emissions predicted by a wind-erosion model. Predicted emissions were highest for the annualized-bare cluster and lowest for the biocrust cluster, which was characterized by zero or minimal emissions even under conditions of extreme wind. Results illustrate potential trade-offs among ecosystem services including livestock production, soil retention, carbon storage, and biodiversity conservation. Improved understanding of these trade-offs may assist ecosystem managers when evaluating alternative management strategies.

  9. Risk and markets for ecosystem services.

    Science.gov (United States)

    Bendor, Todd K; Riggsbee, J Adam; Doyle, Martin

    2011-12-15

    Market-based environmental regulations (e.g., cap and trade, "payments for ecosystem services") are increasingly common. However, few detailed studies of operating ecosystem markets have lent understanding to how such policies affect incentive structures for improving environmental quality. The largest U.S. market stems from the Clean Water Act provisions requiring ecosystem restoration to offset aquatic ecosystems damaged during development. We describe and test how variations in the rules governing this ecosystem market shift risk between regulators and entrepreneurs to promote ecological restoration. We analyze extensive national scale data to assess how two critical aspects of market structure - (a) the geographic scale of markets and (b) policies dictating the release of credits - affect the willingness of entrepreneurs to enter specific markets and produce credits. We find no discernible relationship between policies attempting to ease market entry and either the number of individual producers or total credits produced. Rather, market entry is primarily related to regional geography (the prevalence of aquatic ecosystems) and regional economic growth. Any improvements to policies governing ecosystem markets require explicit evaluation of the interplay between policy and risk elements affecting both regulators and entrepreneurial credit providers. Our findings extend to emerging, regulated ecosystem markets, including proposed carbon offset mechanisms, biodiversity banking, and water quality trading programs.

  10. Invertebrates, ecosystem services and climate change.

    Science.gov (United States)

    Prather, Chelse M; Pelini, Shannon L; Laws, Angela; Rivest, Emily; Woltz, Megan; Bloch, Christopher P; Del Toro, Israel; Ho, Chuan-Kai; Kominoski, John; Newbold, T A Scott; Parsons, Sheena; Joern, A

    2013-05-01

    The sustainability of ecosystem services depends on a firm understanding of both how organisms provide these services to humans and how these organisms will be altered with a changing climate. Unquestionably a dominant feature of most ecosystems, invertebrates affect many ecosystem services and are also highly responsive to climate change. However, there is still a basic lack of understanding of the direct and indirect paths by which invertebrates influence ecosystem services, as well as how climate change will affect those ecosystem services by altering invertebrate populations. This indicates a lack of communication and collaboration among scientists researching ecosystem services and climate change effects on invertebrates, and land managers and researchers from other disciplines, which becomes obvious when systematically reviewing the literature relevant to invertebrates, ecosystem services, and climate change. To address this issue, we review how invertebrates respond to climate change. We then review how invertebrates both positively and negatively influence ecosystem services. Lastly, we provide some critical future directions for research needs, and suggest ways in which managers, scientists and other researchers may collaborate to tackle the complex issue of sustaining invertebrate-mediated services under a changing climate. © 2012 The Authors. Biological Reviews © 2012 Cambridge Philosophical Society.

  11. Nitrogen cycling process rates across urban ecosystems.

    Science.gov (United States)

    Reisinger, Alexander J; Groffman, Peter M; Rosi-Marshall, Emma J

    2016-09-21

    Nitrogen (N) pollution of freshwater, estuarine, and marine ecosystems is widespread and has numerous environmental and economic impacts. A portion of this excess N comes from urban watersheds comprised of natural and engineered ecosystems which can alter downstream N export. Studies of urban N cycling have focused on either specific ecosystems or on watershed-scale mass balances. Comparisons of specific N transformations across ecosystems are required to contextualize rates from individual studies. Here we reviewed urban N cycling in terrestrial, aquatic, and engineered ecosystems, and compared N processing in these urban ecosystem types to native reference ecosystems. We found that net N mineralization and net nitrification rates were enhanced in urban forests and riparian zones relative to reference ecosystems. Denitrification was highly variable across urban ecosystem types, but no significant differences were found between urban and reference denitrification rates. When focusing on urban streams, ammonium uptake was more rapid than nitrate uptake in urban streams. Additionally, reduction of stormwater runoff coupled with potential decreases in N concentration suggests that green infrastructure may reduce downstream N export. Despite multiple environmental stressors in urban environments, ecosystems within urban watersheds can process and transform N at rates similar to or higher than reference ecosystems. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. The Gene tia, Harbored by the Subtilase-Encoding Pathogenicity Island, Is Involved in the Ability of Locus of Enterocyte Effacement-Negative Shiga Toxin-Producing Escherichia coli Strains To Invade Monolayers of Epithelial Cells

    Science.gov (United States)

    Chiani, Paola; Michelacci, Valeria; Minelli, Fabio; Caprioli, Alfredo; Morabito, Stefano

    2017-01-01

    ABSTRACT Locus of enterocyte effacement (LEE)-negative Shiga toxin (Stx)-producing Escherichia coli (STEC) strains are human pathogens that lack the LEE locus, a pathogenicity island (PAI) involved in the intimate adhesion of LEE-positive strains to the host gut epithelium. The mechanism used by LEE-negative STEC strains to colonize the host intestinal mucosa is still not clear. The cell invasion determinant tia, previously described in enterotoxigenic E. coli strains, has been identified in LEE-negative STEC strains that possess the subtilase-encoding pathogenicity island (SE-PAI). We evaluated the role of the gene tia, present in these LEE-negative STEC strains, in the invasion of monolayers of cultured cells. We observed that these strains were able to invade Caco-2 and HEp-2 cell monolayers and compared their invasion ability with that of a mutant strain in which the gene tia had been inactivated. Mutation of the gene tia resulted in a strong reduction of the invasive phenotype, and complementation of the tia mutation with a functional copy of the gene restored the invasion activity. Moreover, we show that the gene tia is overexpressed in bacteria actively invading cell monolayers, demonstrating that tia is involved in the ability to invade cultured monolayers of epithelial cells shown by SE-PAI-positive E. coli, including STEC, strains. However, the expression of the tia gene in the E. coli K-12 strain JM109 was not sufficient, in its own right, to confer to this strain the ability to invade cell monolayers, suggesting that at least another factor must be involved in the invasion ability displayed by the SE-PAI-positive strains. PMID:28893912

  13. The Gene tia, Harbored by the Subtilase-Encoding Pathogenicity Island, Is Involved in the Ability of Locus of Enterocyte Effacement-Negative Shiga Toxin-Producing Escherichia coli Strains To Invade Monolayers of Epithelial Cells.

    Science.gov (United States)

    Bondì, Roslen; Chiani, Paola; Michelacci, Valeria; Minelli, Fabio; Caprioli, Alfredo; Morabito, Stefano

    2017-12-01

    Locus of enterocyte effacement (LEE)-negative Shiga toxin (Stx)-producing Escherichia coli (STEC) strains are human pathogens that lack the LEE locus, a pathogenicity island (PAI) involved in the intimate adhesion of LEE-positive strains to the host gut epithelium. The mechanism used by LEE-negative STEC strains to colonize the host intestinal mucosa is still not clear. The cell invasion determinant tia , previously described in enterotoxigenic E. coli strains, has been identified in LEE-negative STEC strains that possess the subtilase-encoding pathogenicity island (SE-PAI). We evaluated the role of the gene tia , present in these LEE-negative STEC strains, in the invasion of monolayers of cultured cells. We observed that these strains were able to invade Caco-2 and HEp-2 cell monolayers and compared their invasion ability with that of a mutant strain in which the gene tia had been inactivated. Mutation of the gene tia resulted in a strong reduction of the invasive phenotype, and complementation of the tia mutation with a functional copy of the gene restored the invasion activity. Moreover, we show that the gene tia is overexpressed in bacteria actively invading cell monolayers, demonstrating that tia is involved in the ability to invade cultured monolayers of epithelial cells shown by SE-PAI-positive E. coli , including STEC, strains. However, the expression of the tia gene in the E. coli K-12 strain JM109 was not sufficient, in its own right, to confer to this strain the ability to invade cell monolayers, suggesting that at least another factor must be involved in the invasion ability displayed by the SE-PAI-positive strains. Copyright © 2017 American Society for Microbiology.

  14. Management of invading pathogens should be informed by epidemiology rather than administrative boundaries.

    Science.gov (United States)

    Thompson, Robin N; Cobb, Richard C; Gilligan, Christopher A; Cunniffe, Nik J

    2016-03-24

    Plant and animal disease outbreaks have significant ecological and economic impacts. The spatial extent of control is often informed solely by administrative geography - for example, quarantine of an entire county or state once an invading disease is detected - with little regard for pathogen epidemiology. We present a stochastic model for the spread of a plant pathogen that couples spread in the natural environment and transmission via the nursery trade, and use it to illustrate that control deployed according to administrative boundaries is almost always sub-optimal. We use sudden oak death (caused by Phytophthora ramorum ) in mixed forests in California as motivation for our study, since the decision as to whether or not to deploy plant trade quarantine is currently undertaken on a county-by-county basis for that system. However, our key conclusion is applicable more generally: basing management of any disease entirely upon administrative borders does not balance the cost of control with the possible economic and ecological costs of further spread in the optimal fashion.

  15. Biodiversity, climate change, and ecosystem services

    CSIR Research Space (South Africa)

    Mooney, H

    2009-08-01

    Full Text Available of ecosystems, deepen our understanding of the biological underpinnings for ecosystem service delivery and develop new tools and techniques for maintaining and restoring resilient biological and social systems. We will be building on an ecosystem foundation...

  16. Ecological Values of Mangrove Forest Ecosystem

    OpenAIRE

    Kusmana, Cecep

    1996-01-01

    Research on quantification of ecological values of mangrove forest ecosystem are urgently needed, due to its importance as the basics for utilization and management of resources. From the ecological point of vlew, the main prohlem of mangrove ecosystem is rarity and inconsistency of data and limited accurate methods inquantifying ecological values of that ecosystem. Results show that mangrove has the significant ecological values on coastal ecosystem. However, there must be further research t...

  17. Ecosystems science: Genes to landscapes

    Science.gov (United States)

    ,

    2018-05-09

    Bountiful fisheries, healthy and resilient wildlife, flourishing forests and vibrant grasslands are coveted resources that benefit all Americans. U.S. Geological Survey (USGS) science supports the conservation and management of the Nation’s fish and wildlife, and the landscapes they inhabit. Our biological resources—ecosystems and the wild things that live in them—are the foundation of our conservation heritage and an economic asset to current and future generations of Americans.The USGS Ecosystems Mission Area, the biological research arm of the Department of the Interior (DOI), provides science to help America achieve sustainable management and conservation of its biological resources. This work is done within the broader mission of the USGS—to serve the Nation with science that advances understanding of our natural resources, informs land and water stewardship, and helps safeguard communities from natural and environmental hazards. The Ecosystems Mission Area provides research, technical assistance, and education conducted by Cooperative Research Units and Science Centers located in nearly every State.The quality of life and economic strength in America hinges on healthy ecosystems that support living things and natural processes. Ecosystem science better enables society to understand how and why ecosystems change and to guide actions that can prevent damage to, and restore and sustain ecosystems. It is through this knowledge that informed decisions are made about natural resources that can enhance our Nation’s economic and environmental well-being.

  18. Animal ecosystem engineers modulate the diversity-invasibility relationship.

    Directory of Open Access Journals (Sweden)

    Nico Eisenhauer

    Full Text Available Invasions of natural communities by non-indigenous species are currently rated as one of the most important global-scale threats to biodiversity. Biodiversity itself is known to reduce invasions and increase stability. Disturbances by ecosystem engineers affect the distribution, establishment, and abundance of species but this has been ignored in studies on diversity-invasibility relationships.We determined natural plant invasion into 46 plots varying in the number of plant species (1, 4, and 16 and plant functional groups (1, 2, 3, and 4 for three years beginning two years after the establishment of the Jena Experiment. We sampled subplots where earthworms were artificially added and others where earthworm abundance was reduced. We also performed a seed-dummy experiment to investigate the role of earthworms as secondary seed dispersers along a plant diversity gradient. Horizontal dispersal and burial of seed dummies were significantly reduced in subplots where earthworms were reduced in abundance. Seed dispersal by earthworms decreased with increasing plant species richness and presence of grasses but increased in presence of small herbs. These results suggest that dense vegetation inhibits the surface activity of earthworms. Further, there was a positive relationship between the number of earthworms and the number and diversity of invasive plants. Hence, earthworms decreased the stability of grassland communities against plant invasion.Invasibility decreased and stability increased with increasing plant diversity and, most remarkably, earthworms modulated the diversity-invasibility relationship. While the impacts of earthworms were unimportant in low diverse (low earthworm densities and high diverse (high floral structural complexity plant communities, earthworms decreased the stability of intermediate diverse plant communities against plant invasion. Overall, the results document that fundamental processes in plant communities like plant seed

  19. Review on the Progress of Marine Ecosystem Management

    Institute of Scientific and Technical Information of China (English)

    Yao Xuefen; Zhang Luoping

    2007-01-01

    Along with the industrial development, adverse impacts on the natural environment become more serious, and ecosystem health and ecological security have also been deteriorated.The traditional environment management focused on the shortterm and economic benefits. Such managing pattern is not accommodating to the new situation of increasingly global environment problems and large scale marine environment problems.This paper introduces the advance and definition of a new managing pattern-ecosystem management. Meanwhile, the connotation of ecosystem management was summarized as seven points: Sustainability; Human is an important aspect of ecosystem management; Cooperation is the foundation of ecosystem management; Maintain health and security of ecosystem; Ecological diversity protection characters ecosystem management; Maintain the integrity of ecosystem; Ecosystem management must be founded on scientific theories and precise information. Somebody said Ecosystem Management is "a new label of old ideas". However, there is an essential difference between ecosystem management and traditional environmental management. In the last part of this paper, the differences of the approaches between ecosystem management and traditional environmental management are compared.

  20. Evaluating the governance model of hardware-dependent software ecosystems - a case study of the axis ecosystem

    DEFF Research Database (Denmark)

    Wnuk, Krzysztof; Manikas, Konstantinos; Runeson, Per

    2014-01-01

    specifically, we evaluate the governance model applied by Axis, a network video and surveillance camera producer, that is the platform owner and orchestrator of the Application Development Partner (ADP) software ecosystem. We conduct an exploratory case study collecting data from observations and interviews...... and apply the governance model for prevention and improvement of the software ecosystem health proposed by Jansen and Cusumano. Our results reveal that although the governance actions do not address the majority of their governance model, the ADP ecosystem is considered a growing ecosystem providing...