WorldWideScience

Sample records for riparian forest dynamics

  1. SNAG AND LARGE WOODY DEBRIS DYNAMICS IN RIPARIAN FORESTS

    Science.gov (United States)

    Important components of riparian forests are snags and streamside large woody debris (LWD) because they are functional in maintaining water quality and providing habitat for numerous plants and animals. To effectively manage riparian forests, it is important to understand the dy...

  2. Coevolution of floodplain and riparian forest dynamics on large, meandering rivers

    Science.gov (United States)

    Stella, J. C.; Riddle, J. D.; Battles, J. J.

    2012-12-01

    On large meandering rivers, riparian forests coevolve with the floodplains that support them. Floodplain characteristics such as local disturbance regime, deposition rates and sediment texture drive plant community dynamics, which in turn feed back to the abiotic processes. We investigated floodplain and riparian forest coevolution along the along the Sacramento River (California, USA), a large, mediterranean-climate river that has been extensively regulated for 70 years, but whose 160-km middle reach (Red Bluff to Colusa) retains some channel mobility and natural forest stands. Guided by maps of floodplain change over time and current vegetation cover, we conducted an extensive forest inventory and chronosequence analysis to quantify how abiotic conditions and forest structural characteristics such as tree density, basal area and biomass vary with floodplain age. We inventoried 285 fixed-area plots distributed across 19 large point bars within vegetation patches ranging in age from 4 to 107 years. Two successional trajectories were evident: (1) shifting species dominance over time within forested areas, from willow to cottonwood to walnut, boxelder and valley oak; and (2) patches of shrub willow (primarily Salix exigua) that maintained dominance throughout time. Sediment accretion was reduced in the persistent willow plots compared to the successional forest stands, suggesting an association between higher flood energy and arrested succession. Forested stands 40-60 years old were the most extensive across the chronosequence in terms of floodplain area, and supported the highest biomass, species diversity, and functional wildlife habitat. These stands were dominated by Fremont cottonwood (Populus fremontii) and reached their maxima in terms of tree size and biomass at age 50 years. The persistent willow stands reached their structural maxima earlier (32 years) and supported lower biomass. Basal area and abundance of large trees decreased in stands >90 years old

  3. Ecological assessment of riparian forests in Benin

    NARCIS (Netherlands)

    Natta, A.K.

    2003-01-01

    The present research deals with the flora, phytosociology and ecology of riparian forests. The overall objective of this research is to contribute to a better knowledge of the flora, diversity and ecology of riparian forests in

  4. Quantifying geomorphic controls on riparian forest dynamics using a linked physical-biological model: implications for river corridor conservation

    Science.gov (United States)

    Stella, J. C.; Harper, E. B.; Fremier, A. K.; Hayden, M. K.; Battles, J. J.

    2009-12-01

    In high-order alluvial river systems, physical factors of flooding and channel migration are particularly important drivers of riparian forest dynamics because they regulate habitat creation, resource fluxes of water, nutrients and light that are critical for growth, and mortality from fluvial disturbance. Predicting vegetation composition and dynamics at individual sites in this setting is challenging, both because of the stochastic nature of the flood regime and the spatial variability of flood events. Ecological models that correlate environmental factors with species’ occurrence and abundance (e.g., ’niche models’) often work well in infrequently-disturbed upland habitats, but are less useful in river corridors and other dynamic zones where environmental conditions fluctuate greatly and selection pressures on disturbance-adapted organisms are complex. In an effort to help conserve critical riparian forest habitat along the middle Sacramento River, CA, we are taking a mechanistic approach to quantify linkages between fluvial and biotic processes for Fremont cottonwood (Populus fremontii), a keystone pioneer tree in dryland rivers ecosystems of the U.S. Southwest. To predict the corridor-wide population effects of projected changes to the disturbance regime from flow regulation, climate change, and landscape modifications, we have coupled a physical model of channel meandering with a patch-based population model that incorporates the climatic, hydrologic, and topographic factors critical for tree recruitment and survival. We employed these linked simulations to study the relative influence of the two most critical habitat types--point bars and abandoned channels--in sustaining the corridor-wide cottonwood population over a 175-year period. The physical model uses discharge data and channel planform to predict the spatial distribution of new habitat patches; the population model runs on top of this physical template to track tree colonization and survival on

  5. Biomass and carbon pools of disturbed riparian forests

    Science.gov (United States)

    Laura A. B. Giese; W. M. Aust; Randall K. Kolka; Carl C. Trettin

    2003-01-01

    Quantification of carbon pools as affected by forest age/development can facilitate riparian restoration and increase awareness of the potential for forests to sequester global carbon. Riparian forest biomass and carbon pools were quantified for four riparian forests representing different seral stages in the South Carolina Upper Coastal Plain. Three of the riparian...

  6. Effects of riparian buffer width on wood loading in headwater streams after repeated forest thinning

    Science.gov (United States)

    Julia I. Burton; Deanna H. Olson; Klaus J. Puettmann

    2016-01-01

    Forested riparian buffer zones are used in conjunction with upland forest management, in part, to provide for the recruitment for large wood to streams. Small headwater streams account for the majority of stream networks in many forested regions. Yet, our understanding of how riparian buffer width influences wood dynamics in headwater streams is relatively less...

  7. Evaluating the quality of riparian forest vegetation: the Riparian Forest Evaluation (RFV index

    Directory of Open Access Journals (Sweden)

    Fernando Magdaleno

    2014-08-01

    Full Text Available Aim of study: This paper presents a novel index, the Riparian Forest Evaluation (RFV index, for assessing the ecological condition of riparian forests. The status of riparian ecosystems has global importance due to the ecological and social benefits and services they provide. The initiation of the European Water Framework Directive (2000/60/CE requires the assessment of the hydromorphological quality of natural channels. The Directive describes riparian forests as one of the fundamental components that determine the structure of riverine areas. The RFV index was developed to meet the aim of the Directive and to complement the existing methodologies for the evaluation of riparian forests.Area of study: The RFV index was applied to a wide range of streams and rivers (170 water bodies inSpain.Materials and methods: The calculation of the RFV index is based on the assessment of both the spatial continuity of the forest (in its three core dimensions: longitudinal, transversal and vertical and the regeneration capacity of the forest, in a sampling area related to the river hydromorphological pattern. This index enables an evaluation of the quality and degree of alteration of riparian forests. In addition, it helps to determine the scenarios that are necessary to improve the status of riparian forests and to develop processes for restoring their structure and composition.Main results: The results were compared with some previous tools for the assessment of riparian vegetation. The RFV index got the highest average scores in the basins of northernSpain, which suffer lower human influence. The forests in central and southern rivers got worse scores. The bigger differences with other tools were found in complex and partially altered streams and rivers.Research highlights: The study showed the index’s applicability under diverse hydromorphological and ecological conditions and the main advantages of its application. The utilization of the index allows a

  8. Function, Design, and Establishment of Riparian Forest Buffers: A Review

    OpenAIRE

    Klapproth, Julia Caldwell

    1999-01-01

    Through the interaction of their soils, hydrology, and biotic communities, riparian forests protect and improve water quality, provide habitat for plants and animals, support aquatic communities, and provide many benefits to humans. Virginia, along with other states in the Chesapeake Bay region, has recognized the importance of riparian forests by implementing a plan to restore forested buffers along streams, rivers, and lakes. This project reviews selected literature on riparian forest bu...

  9. Thinning and riparian buffer configuration effects on down wood abundance in headwater streams in coniferous forests

    Science.gov (United States)

    Adrian Ares; Deanna H. Olson; Klaus J. Puettmann

    2013-01-01

    Down wood is associated with the function, structure, and diversity of riparian systems. Considerable knowledge has been generated regarding down wood stocks and dynamics in temperate forests, but there are few studies on effects of silvicultural practices and riparian buffer design on down wood, particularly in headwater streams. We analyzed interactive eff ects of...

  10. Riparian forests, a unique but endangered ecosystem in Benin

    NARCIS (Netherlands)

    Natta, A.K.; Sinsin, B.; Maesen, van der L.J.G.

    2002-01-01

    Riparian forests are often small in area, but are of extreme ecological and economic value for local people. The interest of riparian forests lies in their resources: basically fertile and moist soils, water, wood and non-timber forest products that are utilised by neighbouring populations to

  11. Adaptation of the QBR index for use in riparian forests of central Ohio

    Science.gov (United States)

    Stephanie R. Colwell; David M. Hix

    2008-01-01

    Although high quality riparian forests are an endangered ecosystem type throughout the world, there has been no ecological index to measure the habitat quality of riparian forests in Ohio. The QBR (qualitat del bosc de ribera, or riparian forest quality) index was developed to assess the quality of habitat in Mediterranean forested riparian areas, and we have modified...

  12. Fire history of coniferous riparian forests in the Sierra Nevada

    Science.gov (United States)

    K. Van de Water; M. North

    2010-01-01

    Fire is an important ecological process in many western U.S. coniferous forests, yet high fuel loads, rural home construction and other factors have encouraged the suppression of most wildfires. Using mechanical thinning and prescribed burning, land managers often try to reduce fuels in strategic areas with the highest fuel loads. Riparian forests, however, are often...

  13. Linked in: connecting riparian areas to support forest biodiversity

    Science.gov (United States)

    Marie Oliver; Kelly Burnett; Deanna Olson

    2010-01-01

    Many forest-dwelling species rely on both terrestrial and aquatic habitat for their survival. These species, including rare and little-understood amphibians and arthropods, live in and around headwater streams and disperse overland to neighboring headwater streams. Forest management policies that rely on riparian buffer strips and structurebased management—practices...

  14. Water use sources of desert riparian Populus euphratica forests.

    Science.gov (United States)

    Si, Jianhua; Feng, Qi; Cao, Shengkui; Yu, Tengfei; Zhao, Chunyan

    2014-09-01

    Desert riparian forests are the main body of natural oases in the lower reaches of inland rivers; its growth and distribution are closely related to water use sources. However, how does the desert riparian forest obtains a stable water source and which water sources it uses to effectively avoid or overcome water stress to survive? This paper describes an analysis of the water sources, using the stable oxygen isotope technique and the linear mixed model of the isotopic values and of desert riparian Populus euphratica forests growing at sites with different groundwater depths and conditions. The results showed that the main water source of Populus euphratica changes from water in a single soil layer or groundwater to deep subsoil water and groundwater as the depth of groundwater increases. This appears to be an adaptive selection to arid and water-deficient conditions and is a primary reason for the long-term survival of P. euphratica in the desert riparian forest of an extremely arid region. Water contributions from the various soil layers and from groundwater differed and the desert riparian P. euphratica forests in different habitats had dissimilar water use strategies.

  15. Water-use dynamics of an alien-invaded riparian forest within the Mediterranean climate zone of the Western Cape, South Africa

    Science.gov (United States)

    Scott-Shaw, Bruce C.; Everson, Colin S.; Clulow, Alistair D.

    2017-09-01

    In South Africa, the invasion of riparian forests by alien trees has the potential to affect the country's limited water resources. Tree water-use measurements have therefore become an important component of recent hydrological studies. It is difficult for South African government initiatives, such as the Working for Water (WfW) alien clearing program, to justify alien tree removal and implement rehabilitation unless hydrological benefits are known. Consequently, water use within a riparian forest along the Buffeljags River in the Western Cape of South Africa was monitored over a 3-year period. The site consisted of an indigenous stand of Western Cape afrotemperate forest adjacent to a large stand of introduced Acacia mearnsii. The heat ratio method of the heat pulse velocity sap flow technique was used to measure the sap flow of a selection of indigenous species in the indigenous stand, a selection of A. mearnsii trees in the alien stand and two clusters of indigenous species within the alien stand. The indigenous trees in the alien stand at Buffeljags River showed significant intraspecific differences in the daily sap flow rates varying from 15 to 32 L day-1 in summer (sap flow being directly proportional to tree size). In winter (June), this was reduced to only 7 L day-1 when limited energy was available to drive the transpiration process. The water use in the A. mearnsii trees showed peaks in transpiration during the months of March 2012, September 2012 and February 2013. These periods had high average temperatures, rainfall and high daily vapor pressure deficits (VPDs - average of 1.26 kPa). The average daily sap flow ranged from 25 to 35 L in summer and approximately 10 L in the winter. The combined accumulated daily sap flow per year for the three Vepris lanceolata and three A. mearnsii trees was 5700 and 9200 L, respectively, clearly demonstrating the higher water use of the introduced Acacia trees during the winter months. After spatially upscaling the

  16. Evaluation of the riparian forest state program in Pitangueiras county, Parana

    OpenAIRE

    Peres, Marli Candalaft Alcantara Parra; Universidade Estadual de Londrina/UEL; Ralisch, Ricardo; Universidade Estadual de Londrina/UEL; Ripol, Cristovon Videira; Instituto Paranaense de Assistência Técnica e Extensão Rural do Paraná/EMATER

    2009-01-01

    Riparian forest restoration is fundamental for maintenance of vegetable, animal and human life. The objective of this study was to evaluate the efficiency of a Riparian Forest state program in the enlargement of the riparian forests in Pitangueiras county, state of Paraná, in the period of 2004 to 2006. Concerning the riparian reforestation, it was ansewered the reasons that convinced the farmers to join the program, the main difficulties found in its execution, and their views on environment...

  17. A phytosociological study of riparian forests in Benin (West Africa)

    NARCIS (Netherlands)

    Natta, A.K.; Sinsin, B.; Maesen, van der L.J.G.

    2004-01-01

    Floristic ordination and classification of riparian forests in Benin were derived from a comprehensive floristic inventory. TWINSPAN classification and DCA analysis of a data set of 818 plant species and 180 releve's yielded 12 plant communities. Importance of waterways, relief, topography, latitude

  18. 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...

  19. Effects of dams and geomorphic context on riparian forests of the Elwha River, Washington

    Science.gov (United States)

    Shafroth, Patrick B.; Perry, Laura G; Rose, Chanoane A; Braatne, Jeffrey H

    2016-01-01

    Understanding how dams affect the shifting habitat mosaic of river bottomlands is key for protecting the many ecological functions and related goods and services that riparian forests provide and for informing approaches to riparian ecosystem restoration. We examined the downstream effects of two large dams on patterns of forest composition, structure, and dynamics within different geomorphic contexts and compared them to upstream reference conditions along the Elwha River, Washington, USA. Patterns of riparian vegetation in river segments downstream of the dams were driven largely by channel and bottomland geomorphic responses to a dramatically reduced sediment supply. The river segment upstream of both dams was the most geomorphically dynamic, whereas the segment between the dams was the least dynamic due to substantial channel armoring, and the segment downstream of both dams was intermediate due to some local sediment supply. These geomorphic differences were linked to altered characteristics of the shifting habitat mosaic, including older forest age structure and fewer young Populus balsamifera subsp. trichocarpa stands in the relatively static segment between the dams compared to more extensive early-successional forests (dominated by Alnus rubra and Salix spp.) and pioneer seedling recruitment upstream of the dams. Species composition of later-successional forest communities varied among river segments as well, with greater Pseudotsuga menziesii and Tsuga heterophylla abundance upstream of both dams, Acer spp. abundance between the dams, and P. balsamifera subsp. trichocarpa and Thuja plicata abundance below both dams. Riparian forest responses to the recent removal of the two dams on the Elwha River will depend largely on channel and geomorphic adjustments to the release, transport, and deposition of the large volume of sediment formerly stored in the reservoirs, together with changes in large wood dynamics.

  20. Riparian soil development linked to forest succession above and below dams along the Elwha River, Washington, USA

    Science.gov (United States)

    Perry, Laura G; Shafroth, Patrick B.; Perakis, Steven

    2017-01-01

    Riparian forest soils can be highly dynamic, due to frequent fluvial disturbance, erosion, and sediment deposition, but effects of dams on riparian soils are poorly understood. We examined soils along toposequences within three river segments located upstream, between, and downstream of two dams on the Elwha River to evaluate relationships between riparian soil development and forest age, succession, and channel proximity, explore dam effects on riparian soils, and provide a baseline for the largest dam removal in history. We found that older, later-successional forests and geomorphic surfaces contained soils with finer texture and greater depth to cobble, supporting greater forest floor mass, mineral soil nutrient levels, and cation exchange. Forest stand age was a better predictor than channel proximity for many soil characteristics, though elevation and distance from the channel were often also important, highlighting how complex interactions between fluvial disturbance, sediment deposition, and biotic retention regulate soil development in this ecosystem. Soils between the dams, and to a lesser extent below the lower dam, had finer textures and higher mineral soil carbon, nitrogen, and cation exchange than above the dams. These results suggested that decreased fluvial disturbance below the dams, due to reduced sediment supply and channel stabilization, accelerated soil development. In addition, reduced sediment supply below the dams may have decreased soil phosphorus. Soil δ15N suggested that salmon exclusion by the dams had no discernable effect on nitrogen inputs to upstream soils. Recent dam removal may alter riparian soils further, with ongoing implications for riparian ecosystems.

  1. EnviroAtlas - Memphis, TN - 15m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 15-m riparian buffer that is forested. Forest is defined as Trees & Forest and Woody Wetlands. There is a...

  2. EnviroAtlas - New York, NY - 15m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 15-m riparian buffer that is forested. In this community, forest is defined as Trees & Forest. There is a...

  3. EnviroAtlas - Cleveland, OH - 15m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 15-m riparian buffer that is forested. In this community, forest is defined as Trees & Forest and Woody...

  4. EnviroAtlas - Minneapolis/St. Paul, MN - 51m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. In this community, forest is defined as Trees and Forest and Woody...

  5. EnviroAtlas - New York, NY - 51m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. In this community, forest is defined as Trees & Forest. There is a...

  6. EnviroAtlas - Minneapolis/St. Paul, MN - 15m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 15-m riparian buffer that is forested. In this community, forest is defined as Trees and Forest and Woody...

  7. Soil water nitrate concentrations in giant cane and forest riparian buffer zones

    Science.gov (United States)

    Jon E. Schoonover; Karl W. J. Williard; James J. Zaczek; Jean C. Mangun; Andrew D. Carver

    2003-01-01

    Soil water nitrate concentrations in giant cane and forest riparian buffer zones along Cypress Creek in southern Illinois were compared to determine if the riparian zones were sources or sinks for nitrogen in the rooting zone. Suction lysimeters were used to collect soil water samples from the lower rooting zone in each of the two vegetation types. The cane riparian...

  8. Understanding the Science Behind Riparian Forest Buffers: Effects on Plant and Animal Communities

    OpenAIRE

    Klapproth, Julia C.; Johnson, James E. (James Eric), 1952-

    2009-01-01

    Discusses riparian forests' ability to support many species of wildlife and explains that the importance of a particular riparian area for wildlife will depend on the size of the area, adjoining land uses, riparian vegetation, features inside the area, and the wildlife species of interest.

  9. PHYTOCOENOSES OF URBAN RIPARIAN FORESTS ON THE EXAMPLE OF THE LAS OSOBOWICKI FOREST (WROCŁAW

    Directory of Open Access Journals (Sweden)

    Ewa Stefańska-Krzaczek

    2014-10-01

    Full Text Available The Las Osobowicki forest is remnant riparian woodland of the Odra valley. Floristic data were collected from circular 100m2 plots (with a radius of 5.64m which were systematically chosen in forest communities. Four plant communities were determined within data set. They were represented Fagetalia order and Querco-Fagetea class. Flood prevention caused disappearance of riparian forest species, expansion of common hornbeam and Norway maple expansion and a decrease of species richness. However, spatial distribution of phytocoenoses proves the river influence on the vegetation.

  10. Cicada emergence in southwestern riparian forest: Influences of wildfire and vegetation composition

    Science.gov (United States)

    D. Max Smith; Jeffrey Kelly; Deborah M. Finch

    2006-01-01

    Annually emerging cicadas are a numerically and ecologically dominant species in Southwestern riparian forests. Humans have altered disturbance regimes that structure these forests such that floods are less common and wildfires occur more frequently than was historically the case. Impacts of these changes on primary consumers such as riparian cicadas are unknown....

  11. Avian nest box selection and nest success in burned and unburned southwestern riparian forests

    Science.gov (United States)

    D. Max Smith; Jeffrey F. Kelly; Deborah M. Finch

    2007-01-01

    Riparian forest communities in the southwestern United States were historically structured by a disturbance regime of annual flooding. In recent decades, however, frequency of flooding has decreased and frequency of wildfires has increased. Riparian forests provide important breeding habitat for a large variety of bird species, and the effects of this altered...

  12. Evaluating hillslope and riparian contributions to dissolved nitrogen (N) export from a boreal forest catchment

    Science.gov (United States)

    Blackburn, M.; Ledesma, José L. J.; Näsholm, Torgny; Laudon, Hjalmar; Sponseller, Ryan A.

    2017-02-01

    Catchment science has long held that the chemistry of small streams reflects the landscapes they drain. However, understanding the contribution of different landscape units to stream chemistry remains a challenge which frequently limits our understanding of export dynamics. For limiting nutrients such as nitrogen (N), an implicit assumption is that the most spatially extensive landscape units (e.g., uplands) act as the primary sources to surface waters, while near-stream zones function more often as sinks. These assumptions, based largely on studies in high-gradient systems or in regions with elevated inputs of anthropogenic N, may not apply to low-gradient, nutrient-poor, and peat-rich catchments characteristic of many northern ecosystems. We quantified patterns of N mobilization along a hillslope transect in a northern boreal catchment to assess the extent to which organic matter-rich riparian soils regulate the flux of N to streams. Contrary to the prevailing view of riparian functioning, we found that near-stream, organic soils supported concentrations and fluxes of ammonium (NH4+) and dissolved organic nitrogen that were much higher than the contributing upslope forest soils. These results suggest that stream N chemistry is connected to N mobilization and mineralization within the riparian zone rather than the wider landscape. Results further suggest that water table fluctuation in near-surface riparian soils may promote elevated rates of net N mineralization in these landscapes.

  13. Floodplain forest succession reveals fluvial processes: A hydrogeomorphic model for temperate riparian woodlands.

    Science.gov (United States)

    Egger, Gregory; Politti, Emilio; Lautsch, Erwin; Benjankar, Rohan; Gill, Karen M; Rood, Stewart B

    2015-09-15

    River valley floodplains are physically-dynamic environments where fluvial processes determine habitat gradients for riparian vegetation. These zones support trees and shrubs whose life stages are adapted to specific habitat types and consequently forest composition and successional stage reflect the underlying hydrogeomorphic processes and history. In this study we investigated woodland vegetation composition, successional stage and habitat properties, and compared these with physically-based indicators of hydraulic processes. We thus sought to develop a hydrogeomorphic model to evaluate riparian woodland condition based on the spatial mosaic of successional phases of the floodplain forest. The study investigated free-flowing and dam-impacted reaches of the Kootenai and Flathead Rivers, in Idaho and Montana, USA and British Columbia, Canada. The analyses revealed strong correspondence between vegetation assessments and metrics of fluvial processes indicating morphodynamics (erosion and shear stress), inundation and depth to groundwater. The results indicated that common successional stages generally occupied similar hydraulic environments along the different river segments. Comparison of the spatial patterns between the free-flowing and regulated reaches revealed greater deviation from the natural condition for the braided channel segment than for the meandering segment. This demonstrates the utility of the hydrogeomorphic approach and suggests that riparian woodlands along braided channels could have lower resilience than those along meandering channels and might be more vulnerable to influences such as from river damming or climate change. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Riparian forest buffers mitigate the effects of deforestation on fish assemblages in tropical headwater streams.

    Science.gov (United States)

    Lorion, Christopher M; Kennedy, Brian P

    2009-03-01

    Riparian forest buffers may play a critical role in moderating the impacts of deforestation on tropical stream ecosystems, but very few studies have examined the ecological effects of riparian buffers in the tropics. To test the hypothesis that riparian forest buffers can reduce the impacts of deforestation on tropical stream biota, we sampled fish assemblages in lowland headwater streams in southeastern Costa Rica representing three different treatments: (1) forested reference stream reaches, (2) stream reaches adjacent to pasture with a riparian forest buffer averaging at least 15 m in width on each bank, and (3) stream reaches adjacent to pasture without a riparian forest buffer. Land cover upstream from the study reaches was dominated by forest at all of the sites, allowing us to isolate the reach-scale effects of the three study treatments. Fish density was significantly higher in pasture reaches than in forest and forest buffer reaches, mostly due to an increase in herbivore-detritivores, but fish biomass did not differ among reach types. Fish species richness was also higher in pasture reaches than in forested reference reaches, while forest buffer reaches were intermediate. Overall, the taxonomic and trophic structure of fish assemblages in forest and forest buffer reaches was very similar, while assemblages in pasture reaches were quite distinct. These patterns were persistent across three sampling periods during our 15-month study. Differences in stream ecosystem conditions between pasture reaches and forested sites, including higher stream temperatures, reduced fruit and seed inputs, and a trend toward increased periphyton abundance, appeared to favor fish species normally found in larger streams and facilitate a native invasion process. Forest buffer reaches, in contrast, had stream temperatures and allochthonous inputs more similar to forested streams. Our results illustrate the importance of riparian areas to stream ecosystem integrity in the tropics

  15. The negative influences of the new brazilian forest code on the conservation of riparian forests

    Directory of Open Access Journals (Sweden)

    Silva Normandes Matos da

    2017-12-01

    Full Text Available More than one million hectares of riparian forests were degraded or altered in Mato Grosso State (Brazil up to 2009. The aim of the research is to set a comparative scenario to show differences in the quantification of environmental liabilities in riparian forest areas resulting from the change in native vegetation protection rules due to the transition between Laws 4771/65 and 12651/2012. Data collection took place in a marginal stretch of Vermelho River in Rondonópolis County, Mato Grosso State. The following data set was taken into consideration: aerial images derived from unmanned aerial vehicle, Rapid Eye satellite images and orbital images hosted at Google Earth. The spatial resolution of those images was compared. The aerial photos composed a mosaic that was photo-interpreted to generate land use and occupation classes. The riparian forest areas of a rural property were used as parameter, and their environmental situation was compared in 05 meter and 100 meter strips. Thus, by taking into consideration the current rules, 23,501 m2 of area ceased to be an environmental liability within the riparian forest and became a consolidated rural area. According to the previous Forest Code, in a different scenario, that is, in a set of rural properties, the public authority would receive USD 68,600.00 in fines. The new Brazilian Forestry Code of 2012, which replaces the previous one made in 1965, exempts those responsible for rural property from regenerating previously deforested native vegetation - an obligation established by older Forest Code. We have shown that the new Forest Code has diminished the legal responsibility of the rural owners in relation to the maintenance of forest fragments in their properties.

  16. Forest dynamics.

    Science.gov (United States)

    Frelich, Lee

    2016-01-01

    Forest dynamics encompass changes in stand structure, species composition, and species interactions with disturbance and environment over a range of spatial and temporal scales. For convenience, spatial scale is defined as individual tree, neighborhood, stand, and landscape. Whether a given canopy-leveling disturbance will initiate a sequence of development in structure with little change in composition or initiate an episode of succession depends on a match or mismatch, respectively, with traits of the dominant tree species that allow the species to survive disturbance. When these match, certain species-disturbance type combinations lock in a pattern of stand and landscape dynamics that can persist for several generations of trees; thus, dominant tree species regulate, as well as respond to, disturbance. A complex interaction among tree species, neighborhood effects, disturbance type and severity, landform, and soils determines how stands of differing composition form and the mosaic of stands that compose the landscape. Neighborhood effects (e.g., serotinous seed rain, sprouting, shading, leaf-litter chemistry, and leaf-litter physical properties) operate at small spatial extents of the individual tree and its neighbors but play a central role in forest dynamics by contributing to patch formation at stand scales and dynamics of the entire landscape. Dominance by tree species with neutral to negative neighborhood effects leads to unstable landscape dynamics in disturbance-prone regions, wherein most stands are undergoing succession; stability can only occur under very low-severity disturbance regimes. Dominance by species with positive effects leads to stable landscape dynamics wherein only a small proportion of stands undergo succession at any one time. Positive neighborhood effects are common in temperate and boreal zones, whereas negative effects are more common in tropical climates. Landscapes with positive dynamics have alternate categories of dynamics

  17. Seeing the Forest through the Trees: Citizen Scientists Provide Critical Data to Refine Aboveground Carbon Estimates in Restored Riparian Forests

    Science.gov (United States)

    Viers, J. H.

    2013-12-01

    (< 50 Mg/ha), but significantly less than naturally recruiting riparian forests (50 - 200 Mg/ha). Monitoring and assessment of dynamic ecosystem processes and functions will increasingly use data intensive methodologies; however, this research shows the utility of engaging citizen scientists in developing more robust data streams that not only reduces uncertainty, but also provide invaluable opportunities for improved education and outreach.

  18. The intertwining paths of the density managment and riparian buffer study and the Northwest Forest Plan

    Science.gov (United States)

    Kenneth J. Ruzicka; Deanna H. Olson; Klaus J. Puettmann

    2013-01-01

    Initiated simultaneously, the Density Management and Riparian Buff er Study of western Oregon and the Northwest Forest Plan have had intertwining paths related to federal forest management and policy changes in the Pacifi c Northwest over the last 15 to 20 years. We briefl y discuss the development of the Northwest Forest Plan and how it changed the way forest policy...

  19. Chinese Privet (Ligustrum sinense) removal and its effect on native plant communities of Riparian Forests

    Science.gov (United States)

    James Hanula; Scott Horn; John W. Taylor

    2010-01-01

    Chinese privet is a major invasive shrub within riparian zones throughout the southeastern United States. Weremoved privet shrubs from four riparian forests in October 2005 with a GyrotracH mulching machine or by handfelling with chainsaws and machetes to determine how well these treatments controlled privet and how they affected plant...

  20. Watershed scale assessment of the impact of forested riparian zones on stream water quality

    Science.gov (United States)

    J. A. Webber; K. W. J. Williard; M. R. Whiles; M. L. Stone; J. J. Zaczek; D. K. Davie

    2003-01-01

    Federal and state land management agencies have been promoting forest and grass riparian zones to combat non-point source nutrient and sediment pollution of our nations' waters. The majority of research examining the effectiveness of riparian buffers at reducing nutrient and sediment inputs to streams has been conducted at the field scale. This study took a...

  1. Dendroclimatic signals deduced from riparian versus upland forest interior pines in North Karelia, Finland

    DEFF Research Database (Denmark)

    Helama, Samuli; Arentoft, Birgitte W.; Collin-Haubensak, Olivier

    2013-01-01

    Radial growth of boreal tree species is only rarely studied in riparian habitats. Here we investigated chronologies of earlywood, latewood, and annual ring widths and blue intensity (BI; a surrogate to latewood density) from riparian lake shore and upland forest interior pines (Pinus sylvestris L...

  2. Riparian buffer and density management influences on microclimate of young headwater forests of Western Oregon.

    Science.gov (United States)

    Paul D. Anderson; David J. Larson; Samuel S. Chan

    2007-01-01

    Thinning of 30- to 70-year-old Douglas-fir (Psuedotsuga menziesii [Mirb.] Franco) stands is a common silvicultural activity on federal forest lands of the Pacific Northwest, United States. Empirical relationships among riparian functions, silvicultural treatments, and different riparian buffer widths are not well documented for small headwater...

  3. Soil organic carbon in riparian forests, rice fields, and pastures in Piedras, Tolima, Colombia.

    Directory of Open Access Journals (Sweden)

    Hernán Jair Andrade-Castañeda

    2016-06-01

    Full Text Available The aim of the study was to estimate the soil organic carbon (SOC storage in the interface between riparian forests and a matrix of rice fields and pastures with organic management. The study took place in Piedras, Tolima, Colombia. Two plots in production (rice and pasture were selected and SOC was estimated in these areas and in the edge and the interior of adjacent riparian forests at a depth of 0 to 20 cm. Bulk density and SOC concentration were quantified between May and July, 2013. Potential change in SOC storage due to land use change among rice fields, pastures, and riparian forests was estimated. The interfaces rice field-riparian forest and pasture-riparian forest stored an average of 65.6 and 61.3 t C/ha, respectively, with no statistical differences (p>0.05. Statistical differences were not detected (p>0.05 between agricultural matrices (rice fields and pastures in any of the variables. The sampling position (matrix and the edge and interior of forests had a significant impact (p<0.05 just in bulk density: 1.7 vs 1.1 vs 1.0 g/cm3 in interior and edge of the riparian forests and the matrix, respectively. SOC was not statistically affected (p>0.05 by the position in the riparian forest-matrix interface. Conversion from riparian forests to rice fields or pastures with organic management is not emitting greenhouse gases, on the contrary, it is increasing SOC in 3.2 t C/ha. 

  4. EnviroAtlas - Durham, NC - 51m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the...

  5. EnviroAtlas - Phoenix, AZ - 15m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 15-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the...

  6. EnviroAtlas - Tampa, FL - 15m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 15-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the...

  7. EnviroAtlas - Fresno, CA - 51m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the...

  8. EnviroAtlas - Woodbine, IA - 15m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 15-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the...

  9. Structure, composition and regeneration of riparian forest along an altitudinal gradient in northern Iran

    Science.gov (United States)

    Mohammad Naghi Adel; Hassan Pourbabaei; Ali Salehi; Seyed Jalil Alavi; Daniel C. Dey

    2017-01-01

    In order to protect and understand the regeneration of riparian forests, it is important to understand the environmental conditions that lead to their vegetation differentiation. We evaluated the structure, composition, density and regeneration of woody species in forests along the river Safaroud in Ramsar forest in northern Iran in relation to elevation, soil...

  10. Benefits of riparian forest for the aquatic ecosystem assessed at a large geographic scale

    Directory of Open Access Journals (Sweden)

    Van Looy K.

    2013-04-01

    Full Text Available Claimed benefits of riparian forest cover for the aquatic ecosystem include purification, thermal control, organic matter input and habitat provision, which may improve physicochemical and biotic quality. However, these beneficial effects might be flawed by multiple stressor conditions of intensive agriculture and urbanization in upstream catchments. We examined the relationship between riparian forest cover and physicochemical quality and biotic integrity indices in extensive large scale datasets. Measurements of hydromorphological conditions and riparian forest cover across different buffer widths for 59 × 103 river stretches covering 230 × 103 km of the French river network were coupled with data for physicochemical and biotic variables taken from the national monitoring network. General linear and quantile regression techniques were used to determine responses of physicochemical variables and biological integrity indices for macroinvertebrates and fish to riparian forest cover in selections of intermediate stress for 2nd to 4th order streams. Significant responses to forest cover were found for the nutrient variables and biological indices. According to these responses a 60% riparian forest cover in the 10 m buffer corresponds to good status boundaries for physicochemical and biotic elements. For the 30 m buffer, the observed response suggests that riparian forest coverage of at least 45% corresponds with good ecological status in the aquatic ecosystem. The observed consistent responses indicate significant potential for improving the quality of the aquatic environment by restoring riparian forest. The effects are more substantial in single-stressor environments but remain significant in multi-stressor environments.

  11. Initial riparian down wood dynamics in relation to thinning and buffer width

    Science.gov (United States)

    Paul D. Anderson; Deanna H. Olson; Adrian. Ares

    2013-01-01

    Down wood plays many functional roles in aquatic and riparian ecosystems. Simplifi cation of forest structure and low abundance of down wood in stream channels and riparian areas is a common legacy of historical management in headwater forests west of the Cascade Range in the US northwest. Contemporary management practices emphasize the implementation of vegetation...

  12. Pavement and riparian forest shape the bird community along an urban river corridor

    Directory of Open Access Journals (Sweden)

    Christopher J.W. McClure

    2015-07-01

    Full Text Available Knowledge of habitat use by animals within urban-riparian corridors during the breeding season is important for conservation, yet remains understudied. We examined the bird community along an urban-riparian corridor through metropolitan Boise, Idaho and predicted that occupancy of individual species and species richness would be greater in forested areas than in urbanized areas. We surveyed birds throughout the summers of 2009 and 2010 and quantified the m2 of each cover-type within 50-m, 100-m, and 200-m buffers surrounding each survey location using satellite imagery. Occupancy modeling revealed that eight of 14 species analyzed were positively associated with riparian forest, and no species avoided forest. Species richness was negatively associated with the amount of paved surface within 100 m of a survey site with richness declining by more than two species for every hectare of paved surface. Most associations with cover-types–especially riparian forest–were at ⩾100 m. Therefore, the riparian forest within 100 m of a given site along an urban-riparian corridor should be the most important for maintaining species richness.

  13. [Floristic composition and distribution of the Andean subtropical riparian forests of Lules River, Tucuman, Argentina].

    Science.gov (United States)

    Sirombra, Martín G; Mesa, Leticia M

    2010-03-01

    We studied the floristic composition and distribution of the riparian forest of two hydrographical systems in a subtropical Andean region. Using uni and multivariate techniques, we tested the hypotheses that a differentiable riparian forest exists, composed by native vegetation typical of the Yungas phytogeographical province, and that the distribution of vegetation varied significantly with geomorphologic characteristics. Parallel transects along the water courses were used to collect presence-absence data of vegetation in eleven sites. Detrended Correspondence Analysis defined a group of common riparian species for the studied area (Solanum riparium, Phenax laevigatus, Tipuana tipu, Cestrum parqui, Carica quercifolia, Acacia macracantha, Celtis iguanaea, Juglans australis, Pisoniella arborescens, Baccharis salicifolia, Cinnamomum porphyrium and Eugenia uniflora) and identified two reference sites. The distribution of the riparian vegetation varied significantly with the geomorphic characteristics along the studied sites. Riparian habitats were composed by native and exotic species. A distinct riparian flora, different in structure and function from adjacent terrestrial vegetation, could not be identified. Riparian species were similar to the adjacent terrestrial strata. These species would not be limited by the proximity to the river. Anthropogenic impacts were important factors regulating the introduction and increase of exotic vegetation. The lack of regulation of some activities in the zone could cause serious problems in the integrity of this ecosystem.

  14. Quantifying change in riparian ash forests following the introduction of EAB in Michigan and Indiana

    Science.gov (United States)

    Susan J. Crocker; Dacia M. Meneguzzo

    2012-01-01

    The emerald ash borer (Agrilus planipennis Fairmaire; Coleoptera: Buprestidae; EAB) is an introduced beetle that kills ash (Fraxinus spp.) trees. While most EAB-related ash mortality has been documented in urban areas, the effects of EAB in forested settings, particularly in riparian forests, are not well known. This study utilizes...

  15. Breeding birds in riparian and upland dry forests of the Cascade Range

    Science.gov (United States)

    John F. Lehmkuhl; E. Dorsey Burger; Emily K. Drew; John P. Lindsey; Maryellen Haggard; Kent Z. Woodruff

    2007-01-01

    We quantified breeding bird abundance, diversity, and indicator species in riparian and upland dry forests along six third- to fourth-order streams on the east slope of the Cascade Range, Washington, USA. Upland mesic forest on southerly aspects was dominated by open ponderosa pine (Pinus ponderosa) and dry Douglas-fir (Pseudotsuga menziesii...

  16. Environmental and Anthropogenic Factors Influencing Salamanders in Riparian Forests: A Review

    Directory of Open Access Journals (Sweden)

    Hannah L. Clipp

    2014-11-01

    Full Text Available Salamanders and riparian forests are intimately interconnected. Salamanders are integral to ecosystem functions, contributing to vertebrate biomass and complex food webs in riparian forests. In turn, these forests are critical ecosystems that perform many environmental services, facilitate high biodiversity and species richness, and provide habitat to salamander populations. Due to the global decline of amphibians, it is important to understand, as thoroughly and holistically as possible, the roles of environmental parameters and the impact of human activities on salamander abundance and diversity in riparian forests. To determine the population responses of salamanders to a variety of environmental factors and anthropogenic activities, we conducted a review of published literature that compared salamander abundance and diversity, and then summarized and synthesized the data into general patterns. We identify stream quality, leaf litter and woody debris, riparian buffer width, and soil characteristics as major environmental factors influencing salamander populations in riparian forests, describe and explain salamander responses to those factors, and discuss the effects of anthropogenic activities such as timber harvest, prescribed fires, urbanization, road construction, and habitat fragmentation. This review can assist land and natural resource managers in anticipating the consequences of human activities and preparing strategic conservation plans.

  17. Arthropod prey for riparian associated birds in headwater forests of the Oregon Coast Range

    Science.gov (United States)

    Hagar, Joan C.; Li, Judith; Sobota, Janel; Jenkins, Stephanie

    2012-01-01

    Headwater riparian areas occupy a large proportion of the land base in Pacific Northwest forests, and thus are ecologically and economically important. Although a primary goal of management along small headwater streams is the protection of aquatic resources, streamside habitat also is important for many terrestrial wildlife species. However, mechanisms underlying the riparian associations of some terrestrial species have not been well studied, particularly for headwater drainages. We investigated the diets of and food availability for four bird species associated with riparian habitats in montane coastal forests of western Oregon, USA. We examined variation in the availability of arthropod prey as a function of distance from stream. Specifically, we tested the hypotheses that (1) emergent aquatic insects were a food source for insectivorous birds in headwater riparian areas, and (2) the abundances of aquatic and terrestrial arthropod prey did not differ between streamside and upland areas during the bird breeding season. We found that although adult aquatic insects were available for consumption throughout the study period, they represented a relatively small proportion of available prey abundance and biomass and were present in only 1% of the diet samples from only one of the four riparian-associated bird species. Nonetheless, arthropod prey, comprised primarily of insects of terrestrial origin, was more abundant in streamside than upland samples. We conclude that food resources for birds in headwater riparian areas are primarily associated with terrestrial vegetation, and that bird distributions along the gradient from streamside to upland may be related to variation in arthropod prey availability. Because distinct vegetation may distinguish riparian from upland habitats for riparian-associated birds and their terrestrial arthropod prey, we suggest that understory communities be considered when defining management zones for riparian habitat.

  18. Landscape structure, groundwater dynamics, and soil water content influence soil respiration across riparian-hillslope transitions in the Tenderfoot Creek Experimental Forest, Montana

    Science.gov (United States)

    Vincent J. Pacific; Brian L. McGlynn; Diego A. Riveros-Iregui; Daniel L. Welsch; Howard E. Epstein

    2011-01-01

    Variability in soil respiration at various spatial and temporal scales has been the focus of much research over the last decade aimed to improve our understanding and parameterization of physical and environmental controls on this flux. However, few studies have assessed the control of landscape position and groundwater table dynamics on the spatiotemporal variability...

  19. Surface runoff generation in a small watershed covered by sugarcane and riparian forest

    Directory of Open Access Journals (Sweden)

    Rafael Pires Fernandes

    2013-12-01

    Full Text Available Since an understanding of how runoff is generated is of great importance to soil conservation, to water availability and to the management of a watershed, the objective of this study was to understand the generation of surface runoff in a watershed covered by sugarcane and riparian forest. Nine surface runoff plots were set up, evenly distributed on the lower, middle and upper slopes. The lower portion was covered by riparian forest. We showed that the average surface runoff coefficient along the slope in the present study was higher than in other studies under different land uses. Furthermore, the surface runoff was higher under sugarcane compared to the riparian forest, especially after sugarcane harvesting. Besides land cover, other factors such as the characteristics of rainfall events, relief and physical soil characteristics such as soil bulk density and saturated hydraulic conductivity influenced the surface runoff generation.

  20. Effects of changes in the riparian forest on the butterfly community (Insecta: Lepidoptera in Cerrado areas

    Directory of Open Access Journals (Sweden)

    Helena S.R. Cabette

    Full Text Available ABSTRACT Preserved riparian vegetation usually has greater environmental complexity than the riparian vegetation modified by human actions. These systems may have a greater availability and diversity of food resources for the species. Our objective was to evaluate the effect of changes on the structure of the riparian forest on species richness, beta diversity and composition of butterfly species in the Cerrado of Mato Grosso. We tested the hypotheses that: (i higher species richness and (ii beta diversity would be recorded in more preserved environments; and (iii species composition would be more homogeneous in disturbed habitats. For hypothesis testing, the riparian vegetation of eight streams were sampled in four periods of the year in a fixed transect of 100 m along the shores. The richness of butterfly species is lower in disturbed than in preserved areas. However, species richness is not affected by habitat integrity. Beta diversity differed among sites, such that preserved sites have greater beta diversity, showing greater variation in species composition. In addition, beta diversity was positively affected by environmental heterogeneity. A total of 23 of the 84 species sampled occurred only in the changed environment, 42 were exclusive to preserved sites and 19 occurred in both environments. The environmental change caused by riparian forest removal drastically affects the butterfly community. Therefore, riparian vegetation is extremely important for butterfly preservation in the Cerrado and may be a true biodiversity oasis, especially during the dry periods, when the biome undergoes water stress and resource supply is more limited.

  1. Floristic composition of the riparian forest in the lower Gramame river, Paraíba, Brazil

    Directory of Open Access Journals (Sweden)

    Hermes de Oliveira Machado Filho

    2015-09-01

    Full Text Available Riparian forest has a key ecological and economic significance to productive chains associated with it. This study aimed to conduct a floristic survey of riparian forest stretches in the Gramame river, state of Paraíba, Brazilian Northeast region, and analyze the floristic similarity with Brazilian riparian vegetation fragments. We found 136 species belonging to 106 genera and 43 families. The most representative families were: Fabaceae (19 spp., Cyperaceae (16 spp., and Rubiaceae (11 spp.. The predominant habit was herbaceous and the best represented biological spectrum was camephyte. Regarding the geographic distribution, there was a predominance of widely distributed species associated with the Neotropical province. The distribution patterns have shown a low similarity between areas, and largely distributed species stand out. Similarity analysis pointed out that the area was floristically related to other two coastal areas in the Brazilian Northeast and Southeast regions. Only species typically related to estuarine environments might explain the floristic connections detected.

  2. Removing Chinese privet from riparian forests still benefits pollinators five years later

    Science.gov (United States)

    Jacob R. Hudson; James Hanula; Scott Horn

    2014-01-01

    Chinese privet (Ligustrum sinense) is an invasive shrub of the Southeastern U.S. that forms dense stands and limits biodiversity. It was removed from heavily infested riparian forests of the Georgia Piedmont in 2005 by mulching machine or chainsaw felling and subsequent herbicide application. Abundance and species richness of bees and butterflies...

  3. Nesting characteristics of mourning doves in central New Mexico: Response to riparian forest change

    Science.gov (United States)

    D. Max Smith; Deborah M. Finch; David L. Hawksworth

    2012-01-01

    Riparian forests of the American Southwest are especially prone to changes in composition and structure due to natural and anthropogenic factors. To determine how breeding mourning doves (Zenaida macroura) respond to these changes, we examined nest site use and nest survival in control plots, fuel reduction plots before and after mechanical thinning, and post-wildfire...

  4. Removing an exotic shrub from riparian forests increases butterfly abundance and diversity

    Science.gov (United States)

    James Hanula; Scott Horn

    2011-01-01

    Invasive plants are one of the greatest threats to endangered insect species and a major threat to Lepidoptera in eastern North America. We investigated the effects of the invasive shrub Chinese privet (Ligustrum sinense) and two methods (mulching or hand-felling) of removing it from riparian forests on butterfly communities and compared them to untreated, heavily...

  5. Rhododendron maximum impacts seed bank composition and richness following Tsuga canadensis loss in riparian forests

    Science.gov (United States)

    Tristan M. Cofer; Katherine J. Elliott; Janis K. Bush; Chelcy F. Miniat

    2018-01-01

    Southern Appalachian riparian forests have undergone changes in composition and function from invasive pathogens and pests. Castanea dentata mortality in the 1930s from chestnut blight (Cryphonectria parasitica) and Tsuga canadensis mortality in the 2000s from the hemlock woolly adelgid (Adelges tsugae) have led to the expansion and...

  6. Greenhouse Gas Dynamics in Streams and Riparian Floodplains located within Forested Landscapes of the US Northeast: Impact of Key Floodplain Geomorphic Features on Greenhouse Gas Production in a Forested Watershed in Northern New York State, USA.

    Science.gov (United States)

    Serchan, S. P.; Vidon, P.

    2015-12-01

    This study measured dissolved greenhouse gas (GHG) concentrations in interstitial water and stream across various "hotspots" in headwater catchments of Archer Creek watershed, New York, USA. Results indicated that stream water was hyper saturated with methane (CH4), and moderately saturated with carbon dioxide (CO2), and nitrous oxide (N2O). The values of dissolved CO2 (88.3 μmol/L), dissolved CH4 (1.2 μmol/L), and dissolved N2O (0.02 μmol/L) found in the stream were 5.8, 432, and 2.3 times in excess of atmospheric equilibrium, respectively. Results of dissolved GHG measured in interstitial water across various sites: riparian dry (RZ-Dry), riparian wet (RZ-Wet), riparian mucky (RZ-Mucky), pool with fine textured bed sediments (IS-fine-sedpool), pool with coarse textured bed sediments (IS-coarse-sed-pool), and riffles (Riffle) indicated high variations in the degree of saturation of all three GHG. RZ-Mucky, RZ-Wet, and IS-fine-sedpool sites were hotspots of CH4 and CO2 relative to other sites. RZ-Dry sites were hotspots of N2O. Multiple linear regression models indicated that dissolved oxygen (D.O.) and dissolved organic carbon (DOC) influenced dissolved CO2 and CH4 at most of the sites. Relationships between dissolved N2O and predictor variables were highly variable across all sites. Patterns of dissolved N2O in relatively oxic RZ-Dry sites (D.O. 5.3 mg/L) were positively correlated with nitrate (NO3) indicating nitrification as a dominant process in N2O production. In contrast, patterns of dissolved N2O were positively correlated with ammonium (NH4+) at RZ-Wet and RZ-Mucky sites where concentrations of D.O. were significantly lower compared to other sites.

  7. Radionuclide transport along a boreal hill slope - elevated soil water concentrations in riparian forest soils

    Energy Technology Data Exchange (ETDEWEB)

    Lidman, Fredrik; Boily, Aasa; Laudon, Hjalmar [Dept. of Forest Ecology and Management, Swedish University of Agricultural Sciences, 901 83 Umeaa (Sweden); Koehler, Stephan J. [Dept. of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, P.O. 7050, 750 07 Uppsala (Sweden)

    2014-07-01

    The transport of radionuclides from forest ecosystems and out into surface waters is a crucial process for understanding the long-term fate of radionuclides in the boreal landscape. Boreal forests are typically dominated by podzol soils, but the streams draining the forests are often lined by highly organic, often peat-like soils, which the radionuclides must pass through in order to reach the stream. This so-called riparian zone therefore represents a fundamentally different biogeochemical environment than ordinary forest soils, e.g. by exhibiting significantly lower pH and higher concentrations of organic colloids, which significantly can affect the mobility of many radionuclides. Since the riparian zone is the last terrestrial environment that the groundwater is in contact with before it enters the stream, previous research has demonstrated its profound impact on the stream water chemistry. Hence, the riparian soils should also be important for the transport and accumulation of radionuclides. Therefore, soil water was sampled using suction lysimeters installed at different depths along a 22 m long forested hill slope transect in northern Sweden, following the flow pathway of the groundwater from the uphill podzol to the riparian zone near the stream channel. The analyses included a wide range of hydrochemical parameters and many radiologically important elements, e.g. U, Th, Ni, C, Sr, Cs, REEs and Cl. The sampling was repeated ten times throughout a year in order to also capture the temporal variability of the soil water chemistry. The water chemistry of the investigated transect displayed a remarkable change as the groundwater approached the stream channel. Strongly increased concentrations of many elements were observed in the riparian soils. For instance, the concentrations of Th were more than 100 times higher than in the riparian zone than in the uphill forest, suggesting that the riparian zone may be a hotspot for radionuclide accumulation. The reason

  8. Simulation of Soil Quality with Riparian Forests and Cultivated with Sugarcane

    Science.gov (United States)

    da Silva, Luiz Gabriel; Colato, Alexandre; Casagrande, José Carlos; Soares, Marcio Roberto; Perissatto Meneghin, Silvana

    2013-04-01

    Riparian forests are entrusted with important hydrological functions, such as riparian zone protection, filtering sediments and nutrients and mitigation of the amount of nutrients and xenobiotic molecules from the surrounding agro ecosystems. The soil was sampled in the depths of 0-0,2 and 0.2-0.4 m and its chemical (nutrient content and organic matter, cationic exchange capacity - CEC, sum of bases-SB, bases saturation, V%, and aluminum saturation, m%); physical (particle size distribution, density and porosity) and microbiological attributes (basal respiration and microbial biomass) were determined. This work aimed to study the liner method of combining data, figures of merit (FoM), weighing process and the scoring functions developed by Wymore and asses the quality of the soil (SQI) by means of chemical, physical and microbiological soil attributes, employing the additive pondered model for two areas of riparian forest at different stages of ecological succession and an adjacent area cultivated with sugar cane, located on the dam shores of Sugar Mill Saint Lucia-Araras/SP. Some hierarchical functions containing FoMs and their parameters were constructed, and from them weights were assigned to each FoM and parameter, in a way that cluster of structures with the same FoMs and parameters with different weights were formed. These clusters were used to calculate the SQI for all vegetal formations considering two types of soil (Oxisol and Podzol), in that way, the SQI was calculated for each combination of vegetation and soil. The SQIs values were usually higher in the oldest riparian forest, while the recent riparian forest showed the smallest SQI values, for both types of soil. The variation of values within a combination vegetation/soil was also different between all combinations, being that the set of values from the oldest riparian forest presented the lowest amplitude. It was also observed that the Oxisols, regardless of the vegetation, presented higher SQIs

  9. Variable density management in riparian reserves: lessons learned from an operational study in managed forests of western Oregon, USA.

    Science.gov (United States)

    Samuel Chan; Paul Anderson; John Cissel; Larry Lateen; Charley Thompson

    2004-01-01

    A large-scale operational study has been undertaken to investigate variable density management in conjunction with riparian buffers as a means to accelerate development of late-seral habitat, facilitate rare species management, and maintain riparian functions in 40-70 year-old headwater forests in western Oregon, USA. Upland variable retention treatments include...

  10. An initial evaluation of potential options for managing riparian reserves of the Aquatic Conservation Strategy of the Northwest Forest Plan

    Science.gov (United States)

    Gordon H. Reeves; Brian R. Pickard; K. Norman. Johnson

    2016-01-01

    The Aquatic Conservation Strategy (ACS) of the Northwest Forest Plan guides management of riparian and aquatic ecosystems on federal lands in western Oregon, western Washington, and northern California. We applied new scientific findings and tools to evaluate two potential options, A and B, for refining interim riparian reserves to meet ACS goals and likely challenges...

  11. The influence of connectivity in forest patches, and riparian vegetation width on stream macroinvertebrate fauna

    Directory of Open Access Journals (Sweden)

    IC Valle

    Full Text Available We assessed two dimensions of stream connectivity: longitudinal (between forest patches along the stream and lateral (riparian vegetation, using macroinvertebrate assemblages as bioindicators. Sites representing different land-uses were sampled in a lowland basin that holds a mosaic of protected areas. Land-use analysis, forest successional stages and riparian zone widths were calculated by the GIS analysis. Macroinvertebrate fauna was strongly affected by land-use. We observed a continuous decrease in the number of sensitive species, %Shredders and IBE-IOC biotic index from the upstream protected area to highly deforested sites, increasing again where the stream crosses a Biological Reserve. When analysing buffer strips, we found aquatic fauna responding to land-use alterations beyond the 30 m riparian corridor (60 m and 100 m wide. We discussed the longitudinal connectivity between forest patches and the riparian vegetation buffer strips necessary to hold high macroinvertebrate diversity. We recommend actions for the increase/maintenance of biodiversity in this and other lowland basins.

  12. Assessing the Effects of Periodic Flooding on the Population Structure and Recruitment Rates of Riparian Tree Forests

    Directory of Open Access Journals (Sweden)

    Jean-Sébastien Berthelot

    2014-08-01

    Full Text Available Riparian forest stands are subjected to a variety of hydrological stresses as a result of annual fluctuations in water levels during the growing season. Spring floods create additional water-related stress as a result of a major inflow of water that floods riverside land. This exploratory study assesses the impacts of successive floods on tree dynamics and regeneration in an active sedimentation area, while determining the age of the stands using the recruitment rates, tree structure and tree rings based on dendrochronological analysis. Environmental data were also recorded for each vegetation quadrat. In total, 2633 tree stems were tallied throughout the quadrats (200 m2, and tree specimens were analyzed based on the various flood zones. A total of 720 specimens were counted (100 m2 strip to measure natural regeneration. Higher recruitment rates are noted for the no-flood zones and lower rates in active floodplains. During the period of the establishment of tree species, the survival rates are comparable between the flood zones and the no-flood zones. Tree diameter distribution reveals a strong predominance of young trees in flooded areas. Different factors appear to come into play in the dynamics of riparian forest stands, including the disruptions associated with successive flooding.

  13. EnviroAtlas - Memphis, TN - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. Forest is defined as Trees & Forest and Woody Wetlands. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  14. EnviroAtlas - Des Moines, IA - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. Forest is defined as Trees & Forest. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://enviroatlas.epa.gov/EnviroAtlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets)

  15. EnviroAtlas - New York, NY - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. In this community, forest is defined as Trees & Forest. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets)

  16. EnviroAtlas - Minneapolis/St. Paul, MN - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. In this community, forest is defined as Trees and Forest and Woody Wetlands. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  17. EnviroAtlas - Cleveland, OH - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. In this community, forest is defined as Trees & Forest and Woody Wetlands. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas ) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets)

  18. EnviroAtlas - Austin, TX - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. Forest is defined as Trees & Forest. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  19. Evapotranspiration Rates of Riparian Forests, Platte River, Nebraska, 2002-06

    Science.gov (United States)

    Landon, Matthew K.; Rus, David L.; Dietsch, Benjamin J.; Johnson, Michaela R.; Eggemeyer, Kathleen D.

    2009-01-01

    Evapotranspiration (ET) in riparian areas is a poorly understood component of the regional water balance in the Platte River Basin, where competing demands have resulted in water shortages in the ground-water/surface-water system. From April 2002 through March 2006, the U.S. Geological Survey, Nebraska Platte River Cooperative Hydrology Study Group, and Central Platte Natural Resources District conducted a micrometeorological study of water and energy balances at two sites in central Nebraska near Odessa and Gothenburg to improve understanding of ET rates and factors affecting them in Platte River riparian forests. A secondary objective of the study was to constrain estimates of ground-water use by riparian vegetation to satisfy ET consumptive demands, a useful input to regional ground-water flow models. Both study sites are located on large islands within the Platte River characterized by a cottonwood-dominated forest canopy on primarily sandy alluvium. Although both sites are typical of riparian forests along the Platte River in Nebraska, the Odessa understory is dominated by deciduous shrubs, whereas the Gothenburg understory is dominated by eastern redcedars. Additionally, seasonal ground-water levels fluctuated more at Odessa than at Gothenburg. The study period of April 2002 through March 2006 encompassed precipitation conditions ranging from dry to wet. This study characterized the components of the water balance in the riparian zone of each site. ET was evaluated from eddy-covariance sensors installed on towers above the forest canopy at a height of 26.1 meters. Precipitation was measured both above and below the forest canopy. A series of sensors measured soil-moisture availability within the unsaturated zone in two different vertical profiles at each site. Changes in ground-water altitude were evaluated from piezometers. The areal footprint represented in the water balance extended up to 800 meters from each tower. During the study, ET was less variable

  20. Effect of emergent aquatic insects on bat foraging in a riparian forest.

    Science.gov (United States)

    Fukui, Dai; Murakami, Masashi; Nakano, Shigeru; Aoi, Toshiki

    2006-11-01

    1. Riparian zones serve several ecological functions for bats. They provide a source of prey and likely provide favourable structural habitats and shelter from predators. Many studies have shown that bats use the space above streams, ponds or riparian vegetation as feeding habitat. These studies, however, have never distinguished between the effects of habitat structure and prey availability on the foraging activities of bats. Such effects can only be distinguished by an experimental approach. We predicted that bat activity along a stream is influenced by the number of emerged aquatic insects. 2. We evaluated the response of terrestrial consumers, insectivorous bats, to changes in the abundance of emergent aquatic insects by conducting a manipulative field experiment. In a deciduous riparian forest in Japan, aquatic insect flux from the stream to the riparian zone was controlled with an insect-proof cover over a 1.2 km stream reach. 3. We estimated the abundance of emergent aquatic and flying terrestrial arthropods near the treatment and control reaches using Malaise traps. The foraging activity of bats was evaluated in both treatment and control reaches using ultrasonic detectors. 4. The insect-proof cover effectively reduced the flux of emergent aquatic insects to the riparian zone adjacent to the treatment reach. Adjacent to the control reach, adult aquatic insect biomass was highest in spring, and then decreased gradually. Terrestrial insect biomass increased gradually during the summer at both treatment and control reaches. 5. Foraging activity of bats was correlated with insect abundance. In spring, foraging activity of bats at the control reach was significantly greater than at the treatment reach, and increased at both sites with increasing terrestrial insect abundance. 6. Our result suggests that the flux of aquatic insects emerging from streams is one of the most important factors affecting the distribution of riparian-foraging bats. As is the case with

  1. Comparison of riparian and upland forest stand structure and fuel loads in beetle infested watersheds, southern Rocky Mountains

    Science.gov (United States)

    Kathleen A. Dwire; Robert Hubbard; Roberto Bazan

    2015-01-01

    Extensive outbreaks of mountain pine beetle (MPB), spruce beetle (SB), and other insects are altering forest stand structure throughout western North America, and thereby contributing to the heterogeneity of fuel distribution. In forested watersheds, conifer-dominated riparian forests frequently occur as narrow linear features in the landscape mosaic and contribute to...

  2. Abundance and species richness of snakes along the Middle Rio Grande riparian forest in New Mexico

    Science.gov (United States)

    Heather L. Bateman; Alice Chung-MacCoubrey; Howard L. Snell; Deborah M. Finch

    2009-01-01

    To understand the effects of removal of non-native plants and fuels on wildlife in the riparian forest of the Middle Rio Grande in New Mexico, we monitored snakes from 2000 to 2006 using trap arrays of drift fences, pitfalls, and funnel traps. We recorded 158 captures of 13 species of snakes from 12 study sites. We captured more snakes in funnel traps than in pitfalls...

  3. Do Riparian Buffers Protect Stream Invertebrate Communities in South American Atlantic Forest Agricultural Areas?

    Science.gov (United States)

    Hunt, L.; Marrochi, N.; Bonetto, C.; Liess, M.; Buss, D. F.; Vieira da Silva, C.; Chiu, M.-C.; Resh, V. H.

    2017-12-01

    We investigated the influence and relative importance of insecticides and other agricultural stressors in determining variability in invertebrate communities in small streams in intensive soy-production regions of Brazil and Paraguay. In Paraguay we sampled 17 sites on tributaries of the Pirapó River in the state of Itapúa and in Brazil we sampled 18 sites on tributaries of the San Francisco River in the state of Paraná. The riparian buffer zones generally contained native Atlantic forest remnants and/or introduced tree species at various stages of growth. In Brazil the stream buffer width was negatively correlated with sediment insecticide concentrations and buffer width was found to have moderate importance in mitigating effects on some sensitive taxa such as mayflies. However, in both regions insecticides had low relative importance in explaining variability in invertebrate communities, while various habitat parameters were more important. In Brazil, the percent coverage of soft depositional sediment in streams was the most important agriculture-related explanatory variable, and the overall stream-habitat score was the most important variable in Paraguay streams. Paraguay and Brazil both have laws requiring forested riparian buffers. The ample forested riparian buffer zones typical of streams in these regions are likely to have mitigated the effects of pesticides on stream invertebrate communities. This study provides evidence that riparian buffer regulations in the Atlantic Forest region are protecting stream ecosystems from pesticides and other agricultural stressors. Further studies are needed to determine the minimum buffer widths necessary to achieve optimal protection.

  4. EnviroAtlas - Paterson, NJ - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. EnviroAtlas defines tree buffer for this community as only trees and forest. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  5. Analysis of carbon and nitrogen dynamics in riparian soils: model development.

    Science.gov (United States)

    Brovelli, A; Batlle-Aguilar, J; Barry, D A

    2012-07-01

    The quality of riparian soils and their ability to buffer contaminant releases to aquifers and streams are connected intimately to moisture content and nutrient dynamics, in particular of carbon (C) and nitrogen (N). A multi-compartment model-named the Riparian Soil Model (RSM)-was developed to help investigate the influence and importance of environmental parameters, climatic factors and management practices on soil ecosystem functioning in riparian areas. The model improves existing tools, in particular regarding its capability to simulate a wide range of temporal scales, from days to centuries, along with its ability to predict the concentration and vertical distribution of dissolved organic matter (DOM). It was found that DOM concentration controls the amount of soil organic matter (SOM) stored in the soil as well as the respiration rate. The moisture content was computed using a detailed water budget approach, assuming that within each time step all the water above field capacity drains to the layer underneath, until it becomes fully saturated. A mass balance approach was also used for nutrient transport, whereas the biogeochemical reaction network was developed as an extension of an existing C and N turnover model. Temperature changes across the soil profile were simulated analytically, assuming periodic temperature changes in the topsoil. To verify the consistency of model predictions and to illustrate its capabilities, a synthetic but realistic soil profile in a deciduous forest was simulated. Model parameters were taken from the literature, and model predictions were consistent with experimental observations for a similar scenario. Modelling results stressed the importance of environmental conditions on SOM cycling in soils. The mineral and organic C and N stocks fluctuate at different time scales in response to oscillations in climatic conditions and vegetation inputs/uptake. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Dinâmica de populações de Euglossina (Hymenoptera, Apidae em mata ciliar, Urbano Santos, Maranhão, Brasil Population dynamics of Euglossina (Hymenoptera, Apidae in riparian forest, Urbano Santos, Maranhão, Brazil

    Directory of Open Access Journals (Sweden)

    Cristiane C. de Carvalho

    2006-06-01

    Full Text Available Machos de Euglossina foram coletados por meio de iscas-odores de benzoato de benzila, eucaliptol, eugenol, salicilato de metila, vanilina, durante um ano em área de mata ciliar, no município de Urbano Santos, Maranhão. As coletas foram realizadas mensalmente, entre 8 h e 16 h, totalizando 96 horas de amostragem. Foram amostrados 283 indivíduos, 4 gêneros e 16 espécies. Euglossa Latreille, 1802 foi o gênero mais abundante, seguido por Eufriesea Cockerell, 1909, Eulaema Lepeletier, 1841 e Exaerete Hoffmannsegg, 1817. As espécies mais freqüentes foram Euglossa modestior (Dressler, 1982, Euglossa cordata (Linnaeus, 1758, Eulaema cingulata (Fabricius, 1804, Exaerete smaragdina (Guérin-Menéville, 1845, Eulaema nigrita Lepeletier, 1841 e Euglossa gaianii Dressler, 1982. Eucaliptol foi a essência mais atrativa. As maiores freqüências de visitas ocorreram no período da manhã e a maior diversidade de espécies ocorreu no período chuvoso.Males of Euglossina bees were collected in benzil benzoate, eucaliptol, eugenol, methyl salicylate and vanillin scent baits, during one year in a riparian forest area, located in the municipality of Urbano Santos, Maranhão. The collections were carried out monthly, between 8 am and 4 pm, totalling 96 hours of sampling, resulting in 283 individuals, 4 genera and 16 species. Euglossa Latreille, 1802 was the most abundant genus, followed by Eufriesea Cockerell, 1909, Eulaema Lepeletier, 1841 and Exaerete Hoffmannsegg, 1817. The most frequent species were Euglossa modestior (Dressler, 1982, Euglossa cordata (Linnaeus, 1758, Eulaema cingulata (Fabricius, 1804, Exaerete smaragdina (Guérin-Menéville, 1845, Eulaema nigrita Lepeletier, 1841 and Euglossa gaianii (Dressler, 1982. Eucaliptol was the most attractive chemical bait. The highest frequencies of visits were in the morning and the highest diversity of species occurred in the rainy period.

  7. Regeneration of Salicaceae riparian forests in the Northern Hemisphere: A new framework and management tool.

    Science.gov (United States)

    González, Eduardo; Martínez-Fernández, Vanesa; Shafroth, Patrick B; Sher, Anna A; Henry, Annie L; Garófano-Gómez, Virginia; Corenblit, Dov

    2018-04-25

    Human activities on floodplains have severely disrupted the regeneration of foundation riparian shrub and tree species of the Salicaceae family (Populus and Salix spp.) throughout the Northern Hemisphere. Restoration ecologists initially tackled this problem from a terrestrial perspective that emphasized planting. More recently, floodplain restoration activities have embraced an aquatic perspective, inspired by the expanding practice of managing river flows to improve river health (environmental flows). However, riparian Salicaceae species occupy floodplain and riparian areas, which lie at the interface of both terrestrial and aquatic ecosystems along watercourses. Thus, their regeneration depends on a complex interaction of hydrologic and geomorphic processes that have shaped key life-cycle requirements for seedling establishment. Ultimately, restoration needs to integrate these concepts to succeed. However, while regeneration of Salicaceae is now reasonably well-understood, the literature reporting restoration actions on Salicaceae regeneration is sparse, and a specific theoretical framework is still missing. Here, we have reviewed 105 peer-reviewed published experiences in restoration of Salicaceae forests, including 91 projects in 10 world regions, to construct a decision tree to inform restoration planning through explicit links between the well-studied biophysical requirements of Salicaceae regeneration and 17 specific restoration actions, the most popular being planting (in 55% of the projects), land contouring (30%), removal of competing vegetation (30%), site selection (26%), and irrigation (24%). We also identified research gaps related to Salicaceae forest restoration and discuss alternative, innovative and feasible approaches that incorporate the human component. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Floristic composition of the riparian forest in the lower Gramame river, Paraíba, Brazil

    Directory of Open Access Journals (Sweden)

    Thiago da Silva Farias

    2015-04-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2015v28n3p23 Riparian forest has a key ecological and economic significance to productive chains associated with it. This study aimed to conduct a floristic survey of riparian forest stretches in the Gramame river, state of Paraíba, Brazilian Northeast region, and analyze the floristic similarity with Brazilian riparian vegetation fragments. We found 136 species belonging to 106 genera and 43 families. The most representative families were: Fabaceae (19 spp., Cyperaceae (16 spp., and Rubiaceae (11 spp.. The predominant habit was herbaceous and the best represented biological spectrum was camephyte. Regarding the geographic distribution, there was a predominance of widely distributed species associated with the Neotropical province. The distribution patterns have shown a low similarity between areas, and largely distributed species stand out. Similarity analysis pointed out that the area was floristically related to other two coastal areas in the Brazilian Northeast and Southeast regions. Only species typically related to estuarine environments might explain the floristic connections detected.

  9. EnviroAtlas - Portland, Maine - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  10. EnviroAtlas - Portland, OR - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area.This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (http:/www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  11. EnviroAtlas - Pittsburgh, PA - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  12. EnviroAtlas - Fresno, CA - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area.This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  13. EnviroAtlas - Woodbine, Iowa - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area.This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  14. EnviroAtlas - Phoenix, AZ - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  15. EnviroAtlas - Tampa, FL - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  16. EnviroAtlas - Milwaukee, WI - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  17. EnviroAtlas - Durham, NC - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas ) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets ).

  18. EnviroAtlas - Green Bay, WI - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area.This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets ).

  19. EnviroAtlas - New Bedford, MA - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  20. Historical range of variation assessment for wetland and riparian ecosystems, U.S. Forest Service Rocky Mountain Region

    Science.gov (United States)

    Edward Gage; David J. Cooper

    2013-01-01

    This document provides an overview of historical range of variation concepts and explores their application to wetland and riparian ecosystems in the US Forest Service Rocky Mountain Region (Region 2), which includes National Forests and National Grasslands occurring in the states of Colorado, Wyoming, Nebraska, Kansas, and South Dakota. For each of five ecosystem...

  1. Effectiveness monitoring for the aquatic and riparian component of the Northwest Forest Plan: conceptual framework and options.

    Science.gov (United States)

    Gordon H. Reeves; David B. Hohler; David P. Larsen; David E. Busch; Kim Kratz; Keith Reynolds; Karl F. Stein; Thomas Atzet; Polly Hays; Michael. Tehan

    2004-01-01

    An Aquatic and Riparian Effectiveness Monitoring Plan (AREMP) for the Northwest Forest Plan is intended to characterize the ecological condition of watersheds and aquatic ecosystems. So to determine the effectiveness of the Northwest Forest Plan to meet relevant objectives, this report presents the conceptual foundation of options for use in pilot testing and...

  2. ASSESSMENT OF A 5-YEAR-OLD REHABILITATED RIPARIAN FOREST: IS IT ALREADY SUSTAINABLE?

    Directory of Open Access Journals (Sweden)

    Vinícius Londe

    2015-08-01

    Full Text Available ABSTRACTAs important as the establishment of projects of ecological restoration is its assessment post-implementation to know whether the area is becoming self-sustainable or need to be redirected. In this way, this study aimed to know the current situation of a 5-year-old rehabilitated riparian forest,inserted in an anthropogenic impacted region,at the das Velhas River, Minas Gerais State, studying the canopy openness and recruitment of seedlings as plant indicators. 15 plots were allocated in the forest, where hemispherical photographs were taken to analyze the canopy openness and evaluate all seedlings from 0.30 m to 1.30 m height.Canopy openness ranged from 23.7% to 38.8% between seasons and only 192 seedlings were found,from 13 species, five of them exotic and aggressive. Although canopy openness was low, it seems that lateral penetration of light has been favoring the development and dominancy of plants from invasive species, whereas few native ones have been recruited. The exotic/invasive plants may compromise the success of restoration mainly by competition with native planted species. The outcomes evidenced an unsustainability of the riparian forest and the requirement of some management actions to control exotic and invasive plants and ensure the preservation of the area and its ecological roles over time.

  3. Perspectives on screening winter-flood-tolerant woody species in the riparian protection forests of the three gorges reservoir.

    Science.gov (United States)

    Yang, Fan; Wang, Yong; Chan, Zhulong

    2014-01-01

    The establishment of riparian protection forests in the Three Gorges Reservoir (TGR) is an ideal measure to cope with the eco-environmental problems of the water-level fluctuation zone (WLFZ). Thus, the information for screening winter-flood-tolerant woody plant species is useful for the recovery and re-establishment of the riparian protection forests in the TGR WLFZ. Therefore, we discussed the possibilities of constructing and popularizing riparian protection forests in the TGR WLFZ from several aspects, including the woody plant species distribution in the WLFZ, the survival rate analyses of suitable candidate woody species under controlled flooding conditions, the survival rate investigation of some woody plant species planted in the TGR WLFZ, and the physiological responses of some woody plant species during the recovery stage after winter floods. The results of woody species investigation showed that most woody plant species that existed as annual seedlings in the TGR WLFZ are not suitable candidates for the riparian protection forests. However, arbor species (e.g., Salix matsudana, Populus×canadensis, Morus alba, Pterocarya stenoptera, Taxodium ascendens, and Metasequoia glyptostroboides) and shrub species (e.g., Salix variegata, Distylium chinensis, Lycium chinense, Myricaria laxiflora, and Rosa multiflora) might be considered suitable candidates for the riparian protection forests in the TGR WLFZ by survival rate analyses under controlled winter flooding conditions, and survival rate investigations of woody plant species planted in the TGR WLFZ, respectively. Physiological analyses showed that P.×canadensis, M. alba, L. chinense, and S. variegata could develop specific self-repairing mechanisms to stimulate biomass accumulation and carbohydrate synthesis via the increases in chlorophyll pigments and photosynthesis during recovery after winter floods. Our results suggested these woody plant species could endure the winter flooding stress and recover well

  4. Perspectives on screening winter-flood-tolerant woody species in the riparian protection forests of the three gorges reservoir.

    Directory of Open Access Journals (Sweden)

    Fan Yang

    Full Text Available The establishment of riparian protection forests in the Three Gorges Reservoir (TGR is an ideal measure to cope with the eco-environmental problems of the water-level fluctuation zone (WLFZ. Thus, the information for screening winter-flood-tolerant woody plant species is useful for the recovery and re-establishment of the riparian protection forests in the TGR WLFZ. Therefore, we discussed the possibilities of constructing and popularizing riparian protection forests in the TGR WLFZ from several aspects, including the woody plant species distribution in the WLFZ, the survival rate analyses of suitable candidate woody species under controlled flooding conditions, the survival rate investigation of some woody plant species planted in the TGR WLFZ, and the physiological responses of some woody plant species during the recovery stage after winter floods. The results of woody species investigation showed that most woody plant species that existed as annual seedlings in the TGR WLFZ are not suitable candidates for the riparian protection forests. However, arbor species (e.g., Salix matsudana, Populus×canadensis, Morus alba, Pterocarya stenoptera, Taxodium ascendens, and Metasequoia glyptostroboides and shrub species (e.g., Salix variegata, Distylium chinensis, Lycium chinense, Myricaria laxiflora, and Rosa multiflora might be considered suitable candidates for the riparian protection forests in the TGR WLFZ by survival rate analyses under controlled winter flooding conditions, and survival rate investigations of woody plant species planted in the TGR WLFZ, respectively. Physiological analyses showed that P.×canadensis, M. alba, L. chinense, and S. variegata could develop specific self-repairing mechanisms to stimulate biomass accumulation and carbohydrate synthesis via the increases in chlorophyll pigments and photosynthesis during recovery after winter floods. Our results suggested these woody plant species could endure the winter flooding stress

  5. Decoupling of dissolved organic matter patterns between stream and riparian groundwater in a headwater forested catchment

    Science.gov (United States)

    Bernal, Susana; Lupon, Anna; Catalán, Núria; Castelar, Sara; Martí, Eugènia

    2018-03-01

    Streams are important sources of carbon to the atmosphere, though knowing whether they merely outgas terrestrially derived carbon dioxide or mineralize terrestrial inputs of dissolved organic matter (DOM) is still a big challenge in ecology. The objective of this study was to investigate the influence of riparian groundwater (GW) and in-stream processes on the temporal pattern of stream DOM concentrations and quality in a forested headwater stream, and whether this influence differed between the leaf litter fall (LLF) period and the remaining part of the year (non-LLF). The spectroscopic indexes (fluorescence index, biological index, humification index, and parallel factor analysis components) indicated that DOM had an eminently protein-like character and was most likely originated from microbial sources and recent biological activity in both stream water and riparian GW. However, paired samples of stream water and riparian GW showed that dissolved organic carbon (DOC) and nitrogen (DON) concentrations as well as the spectroscopic character of DOM differed between the two compartments throughout the year. A simple mass balance approach indicated that in-stream processes along the reach contributed to reducing DOC and DON fluxes by 50 and 30 %, respectively. Further, in-stream DOC and DON uptakes were unrelated to each other, suggesting that these two compounds underwent different biogeochemical pathways. During the LLF period, stream DOC and DOC : DON ratios were higher than during the non-LLF period, and spectroscopic indexes suggested a major influence of terrestrial vegetation on stream DOM. Our study highlights that stream DOM is not merely a reflection of riparian GW entering the stream and that headwater streams have the capacity to internally produce, transform, and consume DOM.

  6. Regeneration of Salicaceae riparian forests in the Northern Hemisphere: A new framework and management tool

    Science.gov (United States)

    Gonzalez, Eduardo; Martinez-Fernandez, Vanesa; Shafroth, Patrick B.; Sher, Anna A.; Henry, Annie L.; Garofano-Gomez, Virginia; Corenblit, Dov

    2018-01-01

    Human activities on floodplains have severely disrupted the regeneration of foundation riparian shrub and tree species of the Salicaceae family (Populus and Salix spp.) throughout the Northern Hemisphere. Restoration ecologists initially tackled this problem from a terrestrial perspective that emphasized planting. More recently, floodplain restoration activities have embraced an aquatic perspective, inspired by the expanding practice of managing river flows to improve river health (environmental flows). However, riparian Salicaceae species occupy floodplain and riparian areas, which lie at the interface of both terrestrial and aquatic ecosystems along watercourses. Thus, their regeneration depends on a complex interaction of hydrologic and geomorphic processes that have shaped key life-cycle requirements for seedling establishment. Ultimately, restoration needs to integrate these concepts to succeed. However, while regeneration of Salicaceae is now reasonably well-understood, the literature reporting restoration actions on Salicaceae regeneration is sparse, and a specific theoretical framework is still missing. Here, we have reviewed 105 peer-reviewed published experiences in restoration of Salicaceae forests, including 91 projects in 10 world regions, to construct a decision tree to inform restoration planning through explicit links between the well-studied biophysical requirements of Salicaceaeregeneration and 17 specific restoration actions, the most popular being planting (in 55% of the projects), land contouring (30%), removal of competing vegetation (30%), site selection (26%), and irrigation (24%). We also identified research gaps related to Salicaceae forest restoration and discuss alternative, innovative and feasible approaches that incorporate the human component.

  7. Colonization by benthic macroinvertebrates in two artificial substrate types of a Riparian Forest

    Directory of Open Access Journals (Sweden)

    Lívia Borges dos Santos

    Full Text Available Abstract: Aim To analyze the efficiency of organic and inorganic substrates in samples of benthic macroinvertebrates of riparian forests from the Cerrado. Specific objectives (i characterize the ecological succession and taxonomic richness of benthic macroinvertebrates in stream affluent of a riparian forest; (ii analyze the influence of seasonality on the colonization of macroinvertebrates; and (iii determine the effect of the types of artificial substrates on the richness, composition and abundance of the benthic community. Methods Sampling was carried out in the rainy and dry seasons, and we installed in the watercourse two types of substrates: organic (leaf packs and inorganic (bricks, organized in pairs. Six samples per season were done to verify colonization, succession, richness and abundance of benthic community. The substrates were carefully sorted and the organisms were identified to the lowest possible taxonomic level. Results The ecological succession was clearly observed, with the initial occurrence of Chironomidae and Baetidae (considered early colonizers, and a late occurrence of organisms such as Helotrephidae and Trichoptera (considered late colonizers. No significant difference was found in the richness and abundance among the studied seasons (rainy and dry, but the organic substrate was significantly higher than the inorganic substrate for these parameters. Conclusion Organic artificial substrates are more efficient in characterizing the community of benthic macroinvertebrates in the study area, because they are more similar to the conditions of the substrate found naturally in the environment.

  8. Effects of groundwater-flow paths on nitrate concentrations across two riparian forest corridors

    Science.gov (United States)

    Speiran, Gary K.

    2010-01-01

    Groundwater levels, apparent age, and chemistry from field sites and groundwater-flow modeling of hypothetical aquifers collectively indicate that groundwater-flow paths contribute to differences in nitrate concentrations across riparian corridors. At sites in Virginia (one coastal and one Piedmont), lowland forested wetlands separate upland fields from nearby surface waters (an estuary and a stream). At the coastal site, nitrate concentrations near the water table decreased from more than 10 mg/L beneath fields to 2 mg/L beneath a riparian forest buffer because recharge through the buffer forced water with concentrations greater than 5 mg/L to flow deeper beneath the buffer. Diurnal changes in groundwater levels up to 0.25 meters at the coastal site reflect flow from the water table into unsaturated soil where roots remove water and nitrate dissolved in it. Decreases in aquifer thickness caused by declines in the water table and decreases in horizontal hydraulic gradients from the uplands to the wetlands indicate that more than 95% of the groundwater discharged to the wetlands. Such discharge through organic soil can reduce nitrate concentrations by denitrification. Model simulations are consistent with field results, showing downward flow approaching toe slopes and surface waters to which groundwater discharges. These effects show the importance of buffer placement over use of fixed-width, streamside buffers to control nitrate concentrations.

  9. INDICATED SPECIES TO RESTORATION OF RIPARIAN FORESTS IN SUBWATERSHED OF PEIXE-BOI RIVER, PARÁ STATE

    Directory of Open Access Journals (Sweden)

    Igor do Vale

    2014-09-01

    Full Text Available http://dx.doi.org/10.5902/1980509815736This study aims to indicate native species to be used in the restoration of degraded riparian forests in the subwatershed of Peixe-Boi river. All trees and shrubs with diameter at breast height (DBH > 5 cm were inventoried in ten areas of secondary forest and six areas of igapó forest. The results were analyzed by Principal Component Analysis and the silviculture of the species was assessed by literature review. In Igapó areas 66 species were found; the areas had low richness and low diversity index of Shannon, when compared with data from the secondary forests. The floristic composition was heterogeneous, and the floristic similarity is higher between areas that are closer geographically. In the secondary forests were found 175 species; the areas showed high abundance of individuals, high species richness, diversity and evenness. Secondary forests were separated according to geographic proximity and age, which is directly linked to the successional stage. The PCA analysis established the ecological importance of 29 tree species; however only ten species had enough silvicultural information. Due to a greater ecological importance and viable silvicultural techniques available in the literature, Carapa guianensis, Pachira aquatica, Spondias mombin, Tapirira guianensis and Virola guianensis are the most suitable species to restore the degraded areas, in association with Inga edulis, Jacaranda copaia, Pseudopiptadenia psilostachya, Simarouba amara and Vismia guianensis of the secondary forests, that can be planted in the borders and in the nearby areas of igapó forests.

  10. Throughfall and stemflow dynamics in a riparian cedar swamp: possible ecohydrological feedbacks

    Science.gov (United States)

    Duval, T. P.

    2012-12-01

    Partitioning of rainfall through forest canopies as throughfall and stemflow have deservedly been the subject of much research in the past; however, very little is known about the fluxes of water and solutes through forested wetland communities. Temperate swamps are characterized by intermittent canopy coverage, with areas that are denser than upland forests of similar species, but also contain canopy gaps of meadow and marsh communities,. Understanding the role of vegetation on the distribution of precipitation in these ecosystems is necessary to effectively constrain water balance estimates and predict possible community responses to shifting climate regimes. This study examines throughfall, stemflow, and interception dynamics in a riparian cedar swamp in Alliston, Ontario, Canada over the 2012 growing season. Throughfall averaged 76 % of above-canopy rainfall; however, there were spatial-magnitude interaction variations within the swamp. For events less than 20 mm, between 17 and 75 % of the measured swamp floor received greater depth of rain than above the canopy, whereas for events greater than 20 mm only between 2 and 23 % of the sampled swamp floor received more water than the actual event. The observed spatial variability in throughfall was not related to leaf area index, suggesting remote sensing modelling efforts may not be an accurate method for quantification of wetland precipitation dynamics. Stemflow along the predominantly cedar trees averaged 5 %; therefore, net precipitation on a seasonal basis in this cedar swamp was 81 % of above canopy rainfall. Throughfall DOC and total nitrogen concentrations averaged 31 and 2.2 mg/L, respectively, with stemflow DOC and TN concentrations averaging 109 and 6.5 mg/L, respectively. These values are much higher than reported for upland forest species. In general, throughfall magnitudes increased and solute concentrations decreased with increasing distance from the existing forest boles. The delivery of high

  11. Impacts of removing Chinese privet from riparian forests on plant communities and tree growth five years later

    Science.gov (United States)

    Jacob R. Hudson; James L. Hanula; Scott Horn

    2014-01-01

    An invasive shrub, Chinese privet (Ligustrum sinense Lour.), was removed from heavily infested riparian forests in the Georgia Piedmont in 2005 by mulching machine or chainsaw felling. Subsequent herbicide treatment eliminated almost all privet by 2007. Recovery of plant communities, return of Chinese privet, and canopy tree growth were measured on...

  12. Removing an invasive shrub (Chinese privet) increases native bee diversity and abundance in riparian forests of the southeastern United States

    Science.gov (United States)

    James L. Hanula; Scott Horn

    2011-01-01

    1. Chinese privet (Ligustrum sinense Lour.) was removed from riparian forests in the Piedmont of Georgia in November 2005 by mulching with a track-mounted mulching machine or by chainsaw felling. The remaining privet in the herbaceous layer was killed with herbicide in December 2006. 2. Bee (Hymentoptera: Apoidea) abundance, diversity and community similarity in the...

  13. Flat Branch monitoring project: stream water temperature and sediment responses to forest cutting in the riparian zone

    Science.gov (United States)

    Barton D. Clinton; James M. Vose; Dick L. Fowler

    2010-01-01

    Stream water protection during timber-harvesting activities is of primary interest to forest managers. In this study, we examine the potential impacts of riparian zone tree cutting on water temperature and total suspended solids. We monitored stream water temperature and total suspended solids before and after timber harvesting along a second-order tributary of the...

  14. Inundation and Fire Shape the Structure of Riparian Forests in the Pantanal, Brazil.

    Science.gov (United States)

    Arruda, Wellinton de Sá; Oldeland, Jens; Paranhos Filho, Antonio Conceição; Pott, Arnildo; Cunha, Nicolay L; Ishii, Iria Hiromi; Damasceno-Junior, Geraldo Alves

    2016-01-01

    Inundation and fire can affect the structure of riparian vegetation in wetlands. Our aim was to verify if there are differences in richness, abundance, basal area, composition and topographic preference of woody species in riparian forests related to the fire history, flooding duration, or the interaction between both. The study was conducted in the riparian forests of the Paraguay River some of which were burned three times between 2001 and 2011. We sampled trees with a girth of at least 5 cm at breast height in 150 5 × 10 m plots (79 burned and 71 unburned). We also measured height of the flood mark and estimated the flooding duration of each plot. We performed Generalized Linear Mixed Models to verify differences in richness, basal area, and abundance of individuals associated to interaction of fire and inundation. We used an analysis of similarity (ANOSIM) and indicator species analysis to identify differences in composition of species and the association with burned and unburned area according to different levels of inundation. Finally, we used a hierarchical set of Generalized Linear Models (GLM), the so-called HOF models, to analyse each species' specific response to inundation based on topography and to determine their preferred optimal topographic position for both burned as well as unburned areas. Richness was positively associated with elevation only in burned areas while abundance was negatively influenced by inundation only in burned areas. Basal area was negatively associated with time of inundation independent of fire history. There were 15 species which were significant indicators for at least one combination of the studied factors. We found nine species in burned areas and 15 in unburned areas, with response curves in HOF models along the inundation gradient. From these, five species shifted their optimal position along the inundation gradient in burned areas. The interaction of fire and inundation did not appear to affect the basal area, but it

  15. Structure and Composition of Old-Growth and Unmanaged Second-Growth Riparian Forests at Redwood National Park, USA

    Directory of Open Access Journals (Sweden)

    Christopher R. Keyes

    2014-02-01

    Full Text Available Restoration of second-growth riparian stands has become an important issue for managers of redwood (Sequoia sempervirens [D. Don] Endl. forest reserves. Identifying differences between old-growth and second-growth forest vegetation is a necessary step in evaluating restoration needs and targets. The objective of this study was to characterize and contrast vegetation structure and composition in old-growth and unmanaged second-growth riparian forests in adjacent, geomorphologically similar watersheds at Redwood National Park. In the old-growth, redwood was the dominant overstory species in terms of stem density, basal area, and importance values. Second-growth was dominated by red alder (Alnus rubra Bong., Douglas-fir (Pseudotsuga menziesii [Mirbel] Franco, and redwood. Understory species were similar in both forests, with several key differences: Oxalis oregana Nutt. and Trillium ovatum Pursh had greater importance values in the old-growth, and Vaccinium parvifolium Sm., Dryopteris spp. and sedges Carex spp. had greater importance values in the second-growth. Notable differences in structure and composition suggest that restoration practices such as thinning could expedite the acquisition of old-growth characteristics in second-growth riparian forests.

  16. Variable Width Riparian Model Enhances Landscape and Watershed Condition

    Science.gov (United States)

    Abood, S. A.; Spencer, L.

    2017-12-01

    Riparian areas are ecotones that represent about 1% of USFS administered landscape and contribute to numerous valuable ecosystem functions such as wildlife habitat, stream water quality and flows, bank stability and protection against erosion, and values related to diversity, aesthetics and recreation. Riparian zones capture the transitional area between terrestrial and aquatic ecosystems with specific vegetation and soil characteristics which provide critical values/functions and are very responsive to changes in land management activities and uses. Two staff areas at the US Forest Service have coordinated on a two phase project to support the National Forests in their planning revision efforts and to address rangeland riparian business needs at the Forest Plan and Allotment Management Plan levels. The first part of the project will include a national fine scale (USGS HUC-12 digits watersheds) inventory of riparian areas on National Forest Service lands in western United States with riparian land cover, utilizing GIS capabilities and open source geospatial data. The second part of the project will include the application of riparian land cover change and assessment based on selected indicators to assess and monitor riparian areas on annual/5-year cycle basis.This approach recognizes the dynamic and transitional nature of riparian areas by accounting for hydrologic, geomorphic and vegetation data as inputs into the delineation process. The results suggest that incorporating functional variable width riparian mapping within watershed management planning can improve riparian protection and restoration. The application of Riparian Buffer Delineation Model (RBDM) approach can provide the agency Watershed Condition Framework (WCF) with observed riparian area condition on an annual basis and on multiple scales. The use of this model to map moderate to low gradient systems of sufficient width in conjunction with an understanding of the influence of distinctive landscape

  17. Effect of river flow fluctuations on riparian vegetation dynamics: Processes and models

    Science.gov (United States)

    Vesipa, Riccardo; Camporeale, Carlo; Ridolfi, Luca

    2017-12-01

    Several decades of field observations, laboratory experiments and mathematical modelings have demonstrated that the riparian environment is a disturbance-driven ecosystem, and that the main source of disturbance is river flow fluctuations. The focus of the present work has been on the key role that flow fluctuations play in determining the abundance, zonation and species composition of patches of riparian vegetation. To this aim, the scientific literature on the subject, over the last 20 years, has been reviewed. First, the most relevant ecological, morphological and chemical mechanisms induced by river flow fluctuations are described from a process-based perspective. The role of flow variability is discussed for the processes that affect the recruitment of vegetation, the vegetation during its adult life, and the morphological and nutrient dynamics occurring in the riparian habitat. Particular emphasis has been given to studies that were aimed at quantifying the effect of these processes on vegetation, and at linking them to the statistical characteristics of the river hydrology. Second, the advances made, from a modeling point of view, have been considered and discussed. The main models that have been developed to describe the dynamics of riparian vegetation have been presented. Different modeling approaches have been compared, and the corresponding advantages and drawbacks have been pointed out. Finally, attention has been paid to identifying the processes considered by the models, and these processes have been compared with those that have actually been observed or measured in field/laboratory studies.

  18. Novel plant communities limit the effects of a managed flood to restore riparian forests along a large regulated river

    Science.gov (United States)

    Cooper, D.J.; Andersen, D.C.

    2012-01-01

    Dam releases used to create downstream flows that mimic historic floods in timing, peak magnitude and recession rate are touted as key tools for restoring riparian vegetation on large regulated rivers. We analysed a flood on the 5th-order Green River below Flaming Gorge Dam, Colorado, in a broad alluvial valley where Fremont cottonwood riparian forests have senesced and little recruitment has occurred since dam completion in 1962. The stable post dam flow regime triggered the development of novel riparian communities with dense herbaceous plant cover. We monitored cottonwood recruitment on landforms inundated by a managed flood equal in magnitude and timing to the average pre-dam flood. To understand the potential for using managed floods as a riparian restoration tool, we implemented a controlled and replicated experiment to test the effects of artificially modified ground layer vegetation on cottonwood seedling establishment. Treatments to remove herbaceous vegetation and create bare ground included herbicide application (H), ploughing (P), and herbicide plus ploughing (H+P). Treatment improved seedling establishment. Initial seedling densities on treated areas were as much as 1200% higher than on neighbouring control (C) areas, but varied over three orders of magnitude among the five locations where manipulations were replicated. Only two replicates showed the expected seedling density rank of (H+P)>P>H>C. Few seedlings established in control plots and none survived 1 year. Seedling density was strongly affected by seed rain density. Herbivory affected growth and survivorship of recruits, and few survived nine growing seasons. Our results suggest that the novel plant communities are ecologically and geomorphically resistant to change. Managed flooding alone, using flows equal to the pre-dam mean annual peak flood, is an ineffective riparian restoration tool where such ecosystem states are present and floods cannot create new habitat for seedling establishment

  19. Caloric content of leaves of five tree species from the riparian vegetation in a forest fragment from South Brazil

    Directory of Open Access Journals (Sweden)

    Leandro Fabrício Fiori

    2015-09-01

    Full Text Available Abstract Aim: The measurement of the caloric content evidences the amount of energy that remains in the leaf and that can be released to the aquatic trophic chain. We assessed the energy content of leaves from five riparian tree species of a forest fragment in south Brazil and analyzed whether leaf caloric content varied between leaf species and between seasons (dry and wet. The studied sites are located in Northwest of Paraná State, inside a Semi-Deciduous Forest fragment beside two headwater streams. Methods Sampling sites were located along the riparian vegetation of these two water bodies, and due to its proximity and absence of statistical differences of caloric values, analyzed as one compartment. Results Caloric content varied significantly among species and among all pairs of species, with exception of Nectandra cuspidata Ness and Calophyllum brasiliensis Cambess. Two species presented significant differences between seasons, Sloanea guianensis (Aubl. Ben and Calophyllum brasiliensis Cambess. Conclusions The absence of significant seasonal differences of energy content for some species may be due to the characteristics of the tropical forest, in which temperature did not varied dramatically between seasons. However, the energy differed between species and seasons for some species, emphasizing the necessity of a preliminary inspection of energy content, before tracing energy fluxes instead of using a single value to all species from riparian vegetation.

  20. Inter-species competition-facilitation in stochastic riparian vegetation dynamics.

    Science.gov (United States)

    Tealdi, Stefano; Camporeale, Carlo; Ridolfi, Luca

    2013-02-07

    Riparian vegetation is a highly dynamic community that lives on river banks and which depends to a great extent on the fluvial hydrology. The stochasticity of the discharge and erosion/deposition processes in fact play a key role in determining the distribution of vegetation along a riparian transect. These abiotic processes interact with biotic competition/facilitation mechanisms, such as plant competition for light, water, and nutrients. In this work, we focus on the dynamics of plants characterized by three components: (1) stochastic forcing due to river discharges, (2) competition for resources, and (3) inter-species facilitation due to the interplay between vegetation and fluid dynamics processes. A minimalist stochastic bio-hydrological model is proposed for the dynamics of the biomass of two vegetation species: one species is assumed dominant and slow-growing, the other is subdominant, but fast-growing. The stochastic model is solved analytically and the probability density function of the plant biomasses is obtained as a function of both the hydrologic and biologic parameters. The impact of the competition/facilitation processes on the distribution of vegetation species along the riparian transect is investigated and remarkable effects are observed. Finally, a good qualitative agreement is found between the model results and field data. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Phenology of Guarea macrophylla Vahl (Meliaceae in subtropical riparian forest in southern Brazil

    Directory of Open Access Journals (Sweden)

    A. Müller

    2017-08-01

    Full Text Available Abstract Climate is one of the main factors that affect plant behavior. The phenology of Guarea macrophylla Vahl, which is a small tree used for reforestation of degraded areas, was monitored for 18 months in a riparian forest at the Schmidt Stream, Campo Bom, in the state of Rio Grande do Sul, southern Brazil. Vegetative (leaf fall and leaf flushing and reproductive events were observed, with the latter divided into flowering (flower buds and anthesis and fruiting (unripe, ripening and ripe fruit. Phenological events were related to temperature, photoperiod and precipitation and their seasonality was verified by circular statistical analysis. Vegetative phenophases were continuous; they were not related to climate factors and presented low intensity, emphasizing the perennial aspect of the species. Flowering occurred during spring and summer. Both flower buds and anthesis were related to temperature and photoperiod. Fruiting was constant and went through all stages of development. Unripe fruits developed during the months with the lowest photoperiod and ripen more intensely in winter, on colder days. Ripe fruit became available for dispersal in spring, in times of longer photoperiod and higher temperatures. Except for leaf fall, all other phenological events showed seasonality in their manifestation. The one-month difference between the onsets of the flowering phases observed in this study indicated that local climate changes induced the early occurrence of this phenophase.

  2. Experimental study on water transport observations of desert riparian forests in the lower reaches of the Tarim River in China.

    Science.gov (United States)

    Chen, Yaning; Li, Weihong; Zhou, Honghua; Chen, Yapeng; XinmingHao; Fu, Aihong; Ma, Jianxin

    2017-06-01

    Studying the water use processes of desert riparian vegetation in arid regions and analyzing the response and adaptation strategies of plants to drought stress are of great significance for developing ecological restoration measures. Based on field monitoring and test analyses of physiological ecological indicators of dominant species (Populus euphratica and Tamarix chinensis) in the desert riparian forest in the lower reaches of the Tarim River, the water relations of P. euphratica and T. chinensis under drought stress are discussed and some water use strategies put forward. The results show that (1) concerning plant water uptake, desert riparian forests depend mainly on groundwater to survive under long-term water stress. (2) Concerning plant water distribution, the survival of P. euphratica and nearby shallow root plants is mainly due to the hydraulic lift and water redistribution of P. euphratica under drought stress. (3) Concerning plant water transport, P. euphratica sustains the survival of competitive and advantageous branches by improving their ability to acquire water while restraining the growth of inferior branches. (4) Concerning plant transpiration, the sap flow curves of daily variations of P. euphratica and T. chinensis were wide-peak sin and narrower-peak respectively. T. chinensis has better environmental adaptability.

  3. Soil Quality under Riparian Forest at Different Stages of Ecological Succession and Cultivated with Sugarcane

    Science.gov (United States)

    Silva, Luiz Gabriel; Casagrande, José Carlos; Colato, Alexandre; Soares, Marcio Roberto; Perissatto Meneghin, Silvana

    2014-05-01

    This work aimed at evaluating the quality of the soil through its chemical, physical and microbiological attributes, using additive pondered model, as well as studying the characteristics of the linear method of combination of data, figures of merit (FoMs), the process of assigning weights and standard score functions, using measurements collected in three areas (two riparian forests and a commercial crop of sugarcane) in two soil types (Oxisol and Podzol) located on the dam shores of Sugar Mill Saint Lucia-Araras/SP. The soil was sampled in the depths of 0-0.2 and 0.2-0.4m, and was determined some of its chemical attributes (nutrient content and organic matter, cationic exchange capacity - CEC, etc.), physical (particle size distribution, density and porosity) and microbiological (microbial biomass and basal respiration). Two models were built, one containing two hierarchical levels of FoMs (Mod1), and another containing three levels (Mod2), in order to try to isolate FoMs highly correlated from each other within a top-level FoM. At FoMs of Mod1 were assigned various combinations of weights, and those of Mod2 were assigned weights from three methods, distribution from fixed value, classification and pair-wise comparison. In the Mod1, in virtually all combinations of weights used, values of Soil Quality Index (SQI) were superior in older forests, while the most recent forest presented the lowest SQI, for both types of soil. The variation of SQI values obtained from the sets of weights used also differed between the combinations tested, with the set of values of the ancient forest showing smaller amplitude. It could also be observed that the sets of values of Oxisol showed higher SQI and lower amplitude in relation to that of Podzol. It was observed that these facts are due mainly to the soil organic matter content (MO), which differs between the vegetations and soil types, and influences many parameters used in the model. Thus, in the structures where MO had

  4. A novel dendrochronological approach reveals drivers of carbon sequestration in tree species of riparian forests across spatiotemporal scales.

    Science.gov (United States)

    Rieger, Isaak; Kowarik, Ingo; Cherubini, Paolo; Cierjacks, Arne

    2017-01-01

    Aboveground carbon (C) sequestration in trees is important in global C dynamics, but reliable techniques for its modeling in highly productive and heterogeneous ecosystems are limited. We applied an extended dendrochronological approach to disentangle the functioning of drivers from the atmosphere (temperature, precipitation), the lithosphere (sedimentation rate), the hydrosphere (groundwater table, river water level fluctuation), the biosphere (tree characteristics), and the anthroposphere (dike construction). Carbon sequestration in aboveground biomass of riparian Quercus robur L. and Fraxinus excelsior L. was modeled (1) over time using boosted regression tree analysis (BRT) on cross-datable trees characterized by equal annual growth ring patterns and (2) across space using a subsequent classification and regression tree analysis (CART) on cross-datable and not cross-datable trees. While C sequestration of cross-datable Q. robur responded to precipitation and temperature, cross-datable F. excelsior also responded to a low Danube river water level. However, CART revealed that C sequestration over time is governed by tree height and parameters that vary over space (magnitude of fluctuation in the groundwater table, vertical distance to mean river water level, and longitudinal distance to upstream end of the study area). Thus, a uniform response to climatic drivers of aboveground C sequestration in Q. robur was only detectable in trees of an intermediate height class and in taller trees (>21.8m) on sites where the groundwater table fluctuated little (≤0.9m). The detection of climatic drivers and the river water level in F. excelsior depended on sites at lower altitudes above the mean river water level (≤2.7m) and along a less dynamic downstream section of the study area. Our approach indicates unexploited opportunities of understanding the interplay of different environmental drivers in aboveground C sequestration. Results may support species-specific and

  5. Assessing Anthropogenic Influence and Edge Effect Influence on Forested Riparian Buffer Spatial Configuration and Structure: An Example Using Lidar Remote Sensing Methods

    Science.gov (United States)

    Wasser, L. A.; Chasmer, L. E.

    2012-12-01

    Forested riparian buffers (FRB) perform numerous critical ecosystem services. However, globally, FRB spatial configuration and structure have been modified by anthropogenic development resulting in widespread ecological degradation as seen in the Gulf of Mexico and the Chesapeake Bay. Riparian corridors within developed areas are particularly vulnerable to disturbance given two edges - the naturally occurring stream edge and the matrix edge. Increased edge length predisposes riparian vegetation to "edge effects", characterized by modified physical and environmental conditions at the interface between the forested buffer and the adjacent landuse, or matrix and forest fragment degradation. The magnitude and distance of edge influence may be further influenced by adjacent landuse type and the width of the buffer corridor at any given location. There is a need to quantify riparian buffer spatial configuration and structure over broad geographic extents and within multiple riparian systems in support of ecologically sound management and landuse decisions. This study thus assesses the influence of varying landuse types (agriculture, suburban development and undeveloped) on forested riparian buffer 3-dimensional structure and spatial configuration using high resolution Light Detection and Ranging (LiDAR) data collected within a headwater watershed. Few studies have assessed riparian buffer structure and width contiguously for an entire watershed, an integral component of watershed planning and restoration efforts such as those conducted throughout the Chesapeake Bay. The objectives of the study are to 1) quantify differences in vegetation structure at the stream and matrix influenced riparian buffer edges, compared to the forested interior and 2) assess continuous patterns of changes in vegetation structure throughout the buffer corridor beginning at the matrix edge and ending at the stream within buffers a) of varying width and b) that are adjacent to varying landuse

  6. Black-chinned hummingbird nest-site selection and nest survival in response to fuel reduction in a southwestern riparian forest

    Science.gov (United States)

    D. Max Smith; Deborah M. Finch; David L. Hawksworth

    2009-01-01

    Despite widespread efforts to avert wildfire by reducing the density of flammable vegetation, little is known about the effects of this practice on the reproductive biology of forest birds. We examined nest-site selection and nest survival of the Black-chinned Hummingbird (Archilochus alexandri) in New Mexico riparian forests treated or not for fuel...

  7. Forest attributes and fuel loads of riparian vs. upland stands in mountain pine beetle infested watersheds, southern Rocky Mountains [Chapter 13

    Science.gov (United States)

    Kathleen A. Dwire; Roberto A. Bazan; Robert Hubbard

    2015-01-01

    Extensive outbreaks of mountain pine beetle (MPB), spruce beetle (SB), and other insects are altering forest stand structure throughout the Western United States, and thereby increasing the natural heterogeneity of fuel distribution. Riparian forests frequently occur as narrow linear features in the landscape mosaic and can contribute to the spatial complexity of...

  8. Effects of Construction of the Digital Multipurpose Range Complex (DMPRC) on Riparian and Stream Ecosystems at Fort Benning, Georgia. Addendum

    Science.gov (United States)

    2009-06-01

    root dynamics in riparian forests. Soil Science Society of America 69(3):729-737. Houser, J. N., P. J. Mulholland, and K. O. Maloney. 2006. Upland...Forested Wetlands, D. M. Amatya and J. Nettles (eds). New Bern, NC. American Society of Agricultural and Biological Engineers, St. Joseph, MI...primary productivity, vegetation composition, structure, and fine root dynamics in riparian forests. Kelly O. Maloney, Ph.D. in Biological Sciences

  9. Methane Fluxes at the Tree Stem, Soil, and Ecosystem-scales in a Cottonwood Riparian Forest

    Science.gov (United States)

    Flanagan, L. B.; Nikkel, D. J.; Scherloski, L. M.; Tkach, R. E.; Rood, S. B.

    2017-12-01

    Trees can emit methane to the atmosphere that is produced by microbes inside their decaying stems or by taking up and releasing methane that is produced by microbes in adjacent, anoxic soil layers. The significance of these two methane production pathways for possible net release to the atmosphere depends on the magnitude of simultaneous oxidation of atmospheric methane that occurs in well-aerated, shallow soil zones. In order to quantify the significance of these processes, we made methane flux measurements using the eddy covariance technique at the ecosystem-scale and via chamber-based methods applied on the soil surface and on tree stems in a riparian cottonwood ecosystem in southern Alberta that was dominated by Populus tree species and their natural hybrids. Tree stem methane fluxes varied greatly among individual Populus trees and changed seasonally, with peak growing season average values of 4 nmol m-2 s-1 (tree surface area basis). When scaled to the ecosystem, the tree stem methane emissions (0.9 nmol m-2 s-1, ground area basis) were slightly higher than average soil surface methane uptake rates (-0.8 nmol m-2 s-1). In addition, we observed regular nighttime increases in methane concentration within the forest boundary layer (by 300 nmol mol-1 on average at 22 m height during July). The majority of the methane concentration build-up was flushed from the ecosystem to the well-mixed atmosphere, with combined eddy covariance and air column storage fluxes reaching values of 70-80 nmol m-2 s-1 for approximately one hour after sunrise. Daily average net methane emission rates at the ecosystem-scale were 4.4 nmol m-2 s-1 during July. Additional lab studies demonstrated that tree stem methane was produced via the CO2-reduction pathway, as tissue in the central stem of living Populus trees was being decomposed. This study demonstrated net methane emission from an upland, cottonwood forest ecosystem, resulting from microbe methane production in tree stems that

  10. Dynamics of secondary forests

    NARCIS (Netherlands)

    Breugel, van M.

    2007-01-01

    The succession of tropical secondary forests on abandoned agricultural fields has been studied since long, most often by comparing stands of different age since abandonment. These so-called chronosequence studies have yielded much insight in general patterns of succession and the constraints and

  11. Insects of the riparian

    Science.gov (United States)

    Terrence J. Rogers

    1996-01-01

    This paper describes life histories, defoliation problems and other activities of insects associated with forest tree species growing along high elevation streams and river banks. In addition, examples of insects and diseases associated with lower elevation riparian areas are given.

  12. Spatial Structure of Soil Macrofauna Diversity and Tree Canopy in Riparian Forest of Maroon River

    Directory of Open Access Journals (Sweden)

    Ehsan Sayad

    2017-02-01

    Full Text Available Introduction: Sustainability and maintenance of riparian vegetation or restoring of degraded sites is critical to sustain inherent ecosystem function and values. Description of patterns in species assemblages and diversity is an essential step before generating hypotheses in functional ecology. If we want to have information about ecosystem function, soil biodiversity is best considered by focusing on the groups of soil organisms that play major roles in ecosystem functioning when exploring links with provision of ecosystem services. Information about the spatial pattern of soil biodiversity at the regional scale is limited though required, e.g. for understanding regional scale effects of biodiversity on ecosystem processes. The practical consequences of these findings are useful for sustainable management of soils and in monitoring soil quality. Soil macrofauna play significant, but largely ignored roles in the delivery of ecosystem services by soils at plot and landscape scales. One main reason responsible for the absence of information about biodiversity at regional scale is the lack of adequate methods for sampling and analyzing data at this dimension. An adequate approach for the analysis of spatial patterns is a transect study in which samples are taken in a certain order and with a certain distance between samples. Geostatistics provide descriptive tools such as variogram to characterize the spatial pattern of continuous and categorical soil attributes. This method allows assessment of consistency of spatial patterns as well as the scale at which they are expressed. This study was conducted to analyze spatial patterns of soil macrofauna in relation to tree canopy in the riparian forest landscape of Maroon. Materilas and Methods: The study was carried out in the Maroon riparian forest of the southeasternIran (30o 38/- 30 o 39/ N and 50 o 9/- 50 o 10/ E. The climate of the study area is semi-arid. Average yearly rainfall is about 350.04 mm

  13. Assessment of a subtropical riparian forest focusing on botanical, meteorological, ecological characterization and chemical analysis of rainwater

    Directory of Open Access Journals (Sweden)

    Vanessa Graeff

    2018-05-01

    Full Text Available Riparian forests are heterogeneous environments, in which epiphytes find ideal conditions to develop. These plants absorb the necessary nutrients for survival from the atmosphere, and their occurrence and distribution can be influenced by the quality and quantity of precipitation. The objective of this research was to perform an integrated analysis of botanical, meteorological and chemical precipitation parameters so as to compare them in fragments of the riparian forest in the lower (São Leopoldo-SL and upper (Caraá-CA stretches of the Rio dos Sinos Hydrographic Basin (RSHB, RS, Brazil. Rainwater was chemically analyzed, the community structure of epiphytic ferns was surveyed and the ecological characterization was evaluated through the Rapid Habitat Assessment Protocol (RHAP. The results showed that the chemical composition of rainwater is influenced by the environment of each area. In the upper stretch (CA, for instance, the main contribution is that of marine ions, while in the lower stretch (SL, the most impacting aspects are urbanization and industrialization. Similarly, the results depict a reduction of richness and a simplification of the community structure of epiphytic ferns and their environmental quality according to the RHAP categories, towards the base level of the RSHB. The integrated analysis, in which different methods were applied, proved to be an efficient tool to evaluate environmental quality. This analysis considers that a greater number of biotic and abiotic variables may be applied in different scenarios.

  14. Forest ownership dynamics of southern forests

    Science.gov (United States)

    Brett J. Butler; David N. Wear

    2013-01-01

    Key FindingsPrivate landowners hold 86 percent of the forest area in the South; two-thirds of this area is owned by families or individuals.Fifty-nine percent of family forest owners own between 1 and 9 acres of forest land, but 60 percent of family-owned forests are in holdings of 100 acres or more.Two-...

  15. Oldman river dam mitigation program downstream vegetation project report, Volume II: The potential effects of an operating plan for the Oldman River dam on Riparian cottonwood forests

    Energy Technology Data Exchange (ETDEWEB)

    Mahoney, J.M.

    1993-01-01

    Extensive cottonwood (poplar) forests exist in the Oldman River valley downstream of the Oldman River dam. Studies of similar forests in nearby river valleys and elsewhere on the western prairies have found significant declines of some riparian forests following river damming. This investigation was initiated to determine the causes of cottonwood forest decline downstream from existing dams in southern Alberta; inventory the existing river valley forests in the Oldman Basin; establish study sites in the Oldman River forests to monitor changes in forest status following commissioning of the Oldman River dam, and evaluate the probable impact of proposed operating plans for the Oldman River dam and associated water control structures on downstream forests. This report summarizes the progress made in the analyses of the probable effects on the survival of the forests, including a discussion of the hydrological conditions essential for cottonwood forest regeneration and an explanation of the effects of altering these characteristics on riparian forests; the hydrological alterations expected along various river reaches in the Oldman Basin with the implementation of the proposed OD05 Oldman Dam operating plan; and preliminary analyses of the problem impacts of the OD05 operating plan on the cottonwood forests along these reaches.

  16. Modeling the effects of anadromous fish nitrogen on the carbon balance of riparian forests in central Idaho

    Science.gov (United States)

    Noble Stuen, A. J.; Kavanagh, K.; Wheeler, T.

    2010-12-01

    Wild anadromous fish such as Pacific Chinook salmon (Oncorynchus tshawytscha) and steelhead (Oncorhyncus mykiss) were once abundant in Idaho, where they deposited their carcasses, rich in marine-derived nutrients (MDN), in the tributaries of the Columbia River. Anadromous fish are believed to have been a historically important nutrient source to the relatively nutrient-poor inland ecosystems of central Idaho, but no longer reach many inland watersheds due to presence of dams. This study investigates the multi-decadal cumulative effect of presence versus absence of anadromous fish nitrogen on net ecosystem exchange (NEE), or net carbon uptake, of riparian forests along historically salmon-bearing streams in the North Fork Boise River watershed, Idaho, in the context of a changing climate. The ecosystem process model BIOME-BGC is used to develop a representative forest ecosystem and predict the impact of decades of addition and continuing absence of MDN on NEE and net primary production (NPP). The study has 2 objectives: 1) to determine whether BIOME-BGC can reasonably simulate the riparian forests of central Idaho. A potentially confounding factor is the complex terrain of the region, particularly regarding soil water: water accumulation in valley bottoms and their riparian zones may lead to discrepancies in soil moisture and productivity of the riparian forest and of the simulations. The model is parameterized using local ecophysiology and site data and validated using field measurements of leaf area and soil moisture. Objective 2): to determine the effects on forest carbon balance and productivity of the presence or ongoing absence of anadromous-fish derived nitrogen. The forest simulation developed in objective 1 is run under two scenarios into the mid-20th century; one continuing without any supplemental nitrogen and one with nitrogen added in levels consistent with estimates of historical deposition by anadromous fish. Both scenarios incorporate warming due to

  17. Structural and compositional controls on transpiration in 40- and 450-year-old riparian forests in western Oregon, USA.

    Science.gov (United States)

    Moore, Georgianne W; Bond, Barbara J; Jones, Julia A; Phillips, Nathan; Meinzer, Federick C

    2004-05-01

    Large areas of forests in the Pacific Northwest are being transformed to younger forests, yet little is known about the impact this may have on hydrological cycles. Previous work suggests that old trees use less water per unit leaf area or sapwood area than young mature trees of the same species in similar environments. Do old forests, therefore, use less water than young mature forests in similar environments, or are there other structural or compositional components in the forests that compensate for tree-level differences? We investigated the impacts of tree age, species composition and sapwood basal area on stand-level transpiration in adjacent watersheds at the H.J. Andrews Forest in the western Cascades of Oregon, one containing a young, mature (about 40 years since disturbance) conifer forest and the other an old growth (about 450 years since disturbance) forest. Sap flow measurements were used to evaluate the degree to which differences in age and species composition affect water use. Stand sapwood basal area was evaluated based on a vegetation survey for species, basal area and sapwood basal area in the riparian area of two watersheds. A simple scaling exercise derived from estimated differences in water use as a result of differences in age, species composition and stand sapwood area was used to estimate transpiration from late June through October within the entire riparian area of these watersheds. Transpiration was higher in the young stand because of greater sap flux density (sap flow per unit sapwood area) by age class and species, and greater total stand sapwood area. During the measurement period, mean daily sap flux density was 2.30 times higher in young compared with old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees. Sap flux density was 1.41 times higher in young red alder (Alnus rubra Bong.) compared with young P. menziesii trees, and was 1.45 times higher in old P. menziesii compared with old western hemlock (Tsuga heterophylla (Raf

  18. Plant litter dynamics in the forest-stream interface: precipitation is a major control across tropical biomes

    OpenAIRE

    Tonin, Alan M.; Gon?alves, Jos? F.; Bambi, Paulino; Couceiro, Sheyla R. M.; Feitoza, Lorrane A. M.; Fontana, Lucas E.; Hamada, Neusa; Hepp, Luiz U.; Lezan-Kowalczuk, V?nia G.; Leite, Gustavo F. M.; Lemes-Silva, Aurea L.; Lisboa, Leonardo K.; Loureiro, Rafael C.; Martins, Renato T.; Medeiros, Adriana O.

    2017-01-01

    Riparian plant litter is a major energy source for forested streams across the world and its decomposition has repercussions on nutrient cycling, food webs and ecosystem functioning. However, we know little about plant litter dynamics in tropical streams, even?though the tropics occupy 40% of the Earth?s land surface. Here we investigated spatial and temporal (along a year cycle) patterns of litter inputs and storage in multiple streams of three tropical biomes in Brazil (Atlantic forest, Ama...

  19. Influence of Vegetation Structure on Lidar-derived Canopy Height and Fractional Cover in Forested Riparian Buffers During Leaf-Off and Leaf-On Conditions

    Science.gov (United States)

    Wasser, Leah; Day, Rick; Chasmer, Laura; Taylor, Alan

    2013-01-01

    Estimates of canopy height (H) and fractional canopy cover (FC) derived from lidar data collected during leaf-on and leaf-off conditions are compared with field measurements from 80 forested riparian buffer plots. The purpose is to determine if existing lidar data flown in leaf-off conditions for applications such as terrain mapping can effectively estimate forested riparian buffer H and FC within a range of riparian vegetation types. Results illustrate that: 1) leaf-off and leaf-on lidar percentile estimates are similar to measured heights in all plots except those dominated by deciduous compound-leaved trees where lidar underestimates H during leaf off periods; 2) canopy height models (CHMs) underestimate H by a larger margin compared to percentile methods and are influenced by vegetation type (conifer needle, deciduous simple leaf or deciduous compound leaf) and canopy height variability, 3) lidar estimates of FC are within 10% of plot measurements during leaf-on periods, but are underestimated during leaf-off periods except in mixed and conifer plots; and 4) depth of laser pulse penetration lower in the canopy is more variable compared to top of the canopy penetration which may influence within canopy vegetation structure estimates. This study demonstrates that leaf-off lidar data can be used to estimate forested riparian buffer canopy height within diverse vegetation conditions and fractional canopy cover within mixed and conifer forests when leaf-on lidar data are not available. PMID:23382966

  20. Trading Natural Riparian Forests for Urban Shelterbelt Plantations—A Sustainability Assessment of the Kökyar Protection Forest in NW China

    Directory of Open Access Journals (Sweden)

    Siegmund Missall

    2018-03-01

    Full Text Available Cities at the fringe of the Taklimakan desert in NW China are prone to dust and sand storms with serious consequences for human well-being. The Kökyar Protection Forest was established in the 1980s as an ecological engineering project with the intent of protecting the city of Aksu, NW China, from these impacts. It is designed as a combination of poplar shelterbelts and orchards, irrigated by river water from the Aksu River, the main tributary of the Tarim River. Prevalent literature describes it as an afforestation project for combatting desertification with manifold positive effects for the economic, social, and environmental dimension of sustainable development. This paper sets out to challenge these claims by a sustainability assessment in which the plantation is examined from a broader perspective, embedding it to the wider context of social and environmental problems in South Xinjiang. Methods comprise evapotranspiration calculations, interviews, a socioeconomic household survey, stakeholder dialogues, and literature research. Results affirm its economic sustainability, but see a mixed record for the social sphere. From the nature conservation point of view, it has to be classified as unsustainable because its high irrigation water consumption results in the downstream desiccation and desertification of natural riparian forests along the Tarim River, causing a forest loss in the downstream area twice the size of the forest gain in the upstream area. There is a trade-off between artificial shelterbelt plantations for urban ecosystem services on the one hand side, and natural riparian forests and their biodiversity on the other hand side. The paper recommends restricting agricultural extension, and using locally adapted less water consuming agroforestry schemes to protect urban dwellers from dust stress.

  1. PLANT INVASIONS IN RHODE ISLAND RIPARIAN ZONES

    Science.gov (United States)

    The vegetation in riparian zones provides valuable wildlife habitat while enhancing instream habitat and water quality. Forest fragmentation, sunlit edges, and nutrient additions from adjacent development may be sources of stress on riparian zones. Landscape plants may include no...

  2. Simulation of Forest Cover Dynamics for Eastern Eurasian Boreal Forests

    Science.gov (United States)

    Shugart, H. H.; Yan, X.; Zhang, N.; Isaev, A. S.; Shuman, J. K.

    2006-12-01

    We are developing and testing a boreal zone forest dynamics model capable of simulating the forest cover dynamics of the Eurasian boreal forest, a major biospheric ecosystem with potentially large roles in the planetary carbon cycle and in the feedback between terrestrial surface and the atmosphere. In appreciating the role of this region in the coupling between atmosphere and terrestrial surface, on must understand the interactions between CO2 source/sink relationships (associated with growing or clearing forests) and the albedo effects (from changes in terrestrial surface cover). There is some evidence that in the Eurasian Boreal zone, the Carbon budget effects from forest change may oppose the albedo changes. This creates complex feedbacks between surface and atmosphere and motivates the need for a forest dynamics model that simultaneous represents forest vegetation and carbon storage and release. A forest dynamics model applied to Eastern Eurasia, FAREAST, has been tested using three types of information: 1. Direct species composition comparisons between simulated and observed mature forests at the same locations; 2. Forest type comparisons between simulated and observed forests along altitudinal gradients of several different mountains; 3. Comparison with forest stands in different succession stages of simulated forests. Model comparisons with independent data indicate the FAREAST model is capable of representing many of the broad features of the forests of Northeastern China. After model validation in the Northeast China region, model applications were developed for the forests of the Russian Far East. Continental-scale forest cover can be simulated to a relatively realistic degree using a forest gap model with standard representations of individual-plant processes. It appears that such a model, validated relatively locally in this case, in Northeastern China, can then be applied over a much larger region and under conditions of climatic change.

  3. Riparian area protection and outdoor recreation: lessons from the Northwest Forest Plan

    Science.gov (United States)

    Patrick Impero Wilson; Troy E. Hall; Linda E. Kruger

    2012-01-01

    The Northwest Forest Plan required the US Forest Service (USFS) to shift its management focus to ecological values rather than the utilitarian ones that had dominated forest policy in the region. This article examines the effects of this shift on the USFS's historic mission to provide recreational access to the region's forests. Focusing on six national...

  4. Feeding ecology of Auchenipterichthys longimanus (Siluriformes: Auchenipteridae in a riparian flooded forest of Eastern Amazonia, Brazil

    Directory of Open Access Journals (Sweden)

    Tiago Magalhães da Silva Freitas

    2011-01-01

    Full Text Available Feeding habits of the midnight catfish Auchenipterichthys longimanus collected in rivers of the Caxiuanã National Forest (Eastern Amazonia, Brazil were investigated through the different hydrological periods (dry, filing, flood and drawdown. A total of 589 specimens were collected throughout seven samplings between July 2008 and July 2009, of which 74 were young males, 177 adult males, 89 young females and 249 adult females. The diet composition (Alimentary index - Ai% was analyzed by a non-metric multidimensional scaling (nMDS and by the analysis of similarity (ANOSIM, which included 37 items grouped into nine categories (Aquatic insects, Other aquatic invertebrates, Arthropods fragment, Fish, Plant fragment, Seeds, Terrestrial insects, Other terrestrial invertebrates, and Terrestrial vertebrates. We also calculated the niche breadth (Levins index and the repletion index (RI%. Differences in the diet composition between hydrological seasons were registered, primarily on diet composition between dry and flood season, but changes related with sex and maturity were not observed. The midnight catfish showed more specialists feeder habit in the flood period (March 2009 and more generalist habits in the dry season (November 2008. The amount of food eaten by A. longimanus based on repletion index (RI%, did not differ significantly from sex and maturity. However, we evidenced differences in RI% when comparing the studied months. These results provide important biological information about the trophic ecology of auchenipterids fish. In view of the higher occurrence of allochthonous items, this research also underpins the importance of riparian forests as critical environments in the maintenance and conservation of wild populations of fish in the Amazon basin.Neste estudo foram investigados os hábitos alimentares do bagre Auchenipterichthys longimanus coletados em rios da Floresta Nacional de Caxiuanã (Amazônia Oriental, Brasil ao longo de diferentes

  5. Noise-driven cooperative dynamics between vegetation and topography in riparian zones

    Science.gov (United States)

    Vesipa, Riccardo; Camporeale, Carlo; Ridolfi, Luca

    2016-04-01

    Riparian ecosystems exhibit complex biotic and abiotic dynamics, where the triad vegetation-sediments-stream determines the eco-geomorphological features of the river landscape. Random fluctuations of the water stage are a key trait of this triad, and a number of behaviors of the fluvial environment can be understood only taking into consideration the role of noise. In fact, in a given plot, vegetation biomass can grow (if the stage is below the plot elevation) or decay (if the stage is above the plot elevation). As a result, biomass exhibits significant temporal variations. In this framework, the capability of vegetation to alter the transect topography (namely, the plot elevation) is crucial. Vegetation can increase the plot elevation by a number of mechanisms (trapping of water- and wind-transported sediment particles, production of organic soil, stabilization of the soil surface). The increment of plot elevation induces the reduction of the plot-specific magnitude, frequency and duration of floods. These more favorable plot-specific hydrological conditions, in turn, induce an increment of biomass. Moreover, the higher the vegetation biomass, the higher the plot elevation increment induced by these mechanisms. In order to elucidate how the stochastically varying water stage and the vegetation-induced topographic alteration shape the bio-morphological characteristics of riparian transects, a stochastic model that takes into account the main links between vegetation, sediments and the stream was adopted. In particular, the capability of vegetation to alter the plot topography was emphasized. In modeling such interactions, the minimalistic approach was pursued. The complex vegetation-sediments-stream interactions were modeled by a set of state-depended stochastic eco-hydraulic equations. The probability density function of vegetation biomass was then analytically evaluated in any transect plot. This pdf strongly depends on the vegetation-topography feedback. We

  6. Crepuscular activity of culicids (Diptera, Culicidae in the peridomicile and in the remaining riparian forest in Tibagi river, State of Paraná, Brazil

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    Gerson A. Müller

    2012-03-01

    Full Text Available Crepuscular activity of culicids (Diptera, Culicidae in the peridomicile and in the remaining riparian forest in Tibagi river, State of Paraná, Brazil. Human-attracted mosquitoes were collected for one hour, around sunset time (half hour before and half after, from April to December 2006, in two environments (riparian forest and near houses, in Tibagi river basin, Palmeira municipality, State of Paraná. Seven-hundred forty-nine mosquitoes, belonging to 13 species, were collected. Psorophora champerico Dyar & Knab, 1906 (42.86% and Psorophora discrucians (Walker, 1856 (40.59% were the most frequent species. No significant differences between quantities of Ps. champerico (t = -0.792; d.f. = 16; p = 0.43 and Ps. discrucians (t = 0.689; d.f. = 16; p = 0.49 obtained in riparian forest and near houses were observed, indicating similar conditions for crepuscular activity of these species in both environments. Psorophora champerico and Ps. discrucians responded (haematophagic activity to environmental stimuli associated with the twilight hours differently in distinct habitats studied. The former species is registered for the first time in the Atlantic forest biome.

  7. The role of riparian vegetation density, channel orientation and water velocity in determining river temperature dynamics

    Science.gov (United States)

    Garner, Grace; Malcolm, Iain A.; Sadler, Jonathan P.; Hannah, David M.

    2017-10-01

    A simulation experiment was used to understand the importance of riparian vegetation density, channel orientation and flow velocity for stream energy budgets and river temperature dynamics. Water temperature and meteorological observations were obtained in addition to hemispherical photographs along a ∼1 km reach of the Girnock Burn, a tributary of the Aberdeenshire Dee, Scotland. Data from nine hemispherical images (representing different uniform canopy density scenarios) were used to parameterise a deterministic net radiation model and simulate radiative fluxes. For each vegetation scenario, the effects of eight channel orientations were investigated by changing the position of north at 45° intervals in each hemispheric image. Simulated radiative fluxes and observed turbulent fluxes drove a high-resolution water temperature model of the reach. Simulations were performed under low and high water velocity scenarios. Both velocity scenarios yielded decreases in mean (≥1.6 °C) and maximum (≥3.0 °C) temperature as canopy density increased. Slow-flowing water resided longer within the reach, which enhanced heat accumulation and dissipation, and drove higher maximum and lower minimum temperatures. Intermediate levels of shade produced highly variable energy flux and water temperature dynamics depending on the channel orientation and thus the time of day when the channel was shaded. We demonstrate that in many reaches relatively sparse but strategically located vegetation could produce substantial reductions in maximum temperature and suggest that these criteria are used to inform future river management.

  8. The spatial distribution and temporal variation of desert riparian forests and their influencing factors in the downstream Heihe River basin, China

    Science.gov (United States)

    Ding, Jingyi; Zhao, Wenwu; Daryanto, Stefani; Wang, Lixin; Fan, Hao; Feng, Qiang; Wang, Yaping

    2017-05-01

    Desert riparian forests are the main restored vegetation community in Heihe River basin. They provide critical habitats and a variety of ecosystem services in this arid environment. Since desert riparian forests are also sensitive to disturbance, examining the spatial distribution and temporal variation of these forests and their influencing factors is important to determine the limiting factors of vegetation recovery after long-term restoration. In this study, field experiment and remote sensing data were used to determine the spatial distribution and temporal variation of desert riparian forests and their relationship with the environmental factors. We classified five types of vegetation communities at different distances from the river channel. Community coverage and diversity formed a bimodal pattern, peaking at the distances of 1000 and 3000 m from the river channel. In general, the temporal normalized difference vegetation index (NDVI) trend from 2000 to 2014 was positive at different distances from the river channel, except for the region closest to the river bank (i.e. within 500 m from the river channel), which had been undergoing degradation since 2011. The spatial distribution of desert riparian forests was mainly influenced by the spatial heterogeneity of soil properties (e.g. soil moisture, bulk density and soil particle composition). Meanwhile, while the temporal variation of vegetation was affected by both the spatial heterogeneity of soil properties (e.g. soil moisture and soil particle composition) and to a lesser extent, the temporal variation of water availability (e.g. annual average and variability of groundwater, soil moisture and runoff). Since surface (0-30 cm) and deep (100-200 cm) soil moisture, bulk density and the annual average of soil moisture at 100 cm obtained from the remote sensing data were regarded as major determining factors of community distribution and temporal variation, conservation measures that protect the soil structure

  9. Dynamics of forest soil chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Alveteg, M

    1998-11-01

    Acidification caused by emissions of nitrogen and sulphur and associated adverse effects on forest ecosystems has been an issue on the political agenda for decades. Temporal aspects of soil acidification and/or recovery can be investigated using the soil chemistry model SAFE, a dynamic version of the steady-state model PROFILE used in critical loads assessment on the national level, e.g. for Sweden. In this thesis, possibilities to replace the use of apparent gibbsite solubility coefficients with a more mechanistic Al sub-model are investigated and a reconstruction model, MAKEDEP, is presented which makes hindcasts and forecasts of atmospheric deposition and nutrient uptake and cycling. A regional application of SAFE/MAKEDEP based on 622 sites in Switzerland is also presented. It is concluded that the quantitative information on pools and fluxes of Al in forest ecosystems is very limited and that there currently exists no mechanistic alternative in modelling soil solution Al. MAKEDEP is a valuable and operational tool for deriving input to dynamic soil chemistry models such as SMART, MAGIC and SAFE. For multi-layer models, e.g. the SAFE model, including nutrient cycling in MAKEDEP is shown to be important. The strength of the regional assessment strategy presented in this thesis lies in its transparency and modularity. All sub-modules, including models, transfer functions, assumptions in the data acquisition strategy, etc., can be checked and replaced individually. As the presented assessment strategy is based on knowledge and data from a wide range of scientists and fields it is of vital importance that the research community challenge the assumptions made. The many measurable intermediate results produced by the included models will hopefully encourage scientists to challenge the models through additional measurements at the calculation sites. It is concluded that current reduction plans are not sufficient for all forest ecosystems in Switzerland to recover from

  10. Quantifying Forested Riparian Buffer Ability to Ameliorate Stream Temperature in a Missouri Ozark Border Stream of the Central U.S

    Science.gov (United States)

    Bulliner, E. A.; Hubbart, J. A.

    2009-12-01

    Riparian buffers play an important role in modulating stream water quality, including temperature. There is a need to better understand riparian form and function to validate and improve contemporary management practices. Further studies are warranted to characterize energy attenuation by forested riparian canopy layers that normally buffer stream temperature, particularly in the central hardwood forest regions of the United States where relationships between canopy density and stream temperature are unknown. To quantify these complex processes, two intensively instrumented hydroclimate stations were installed along two stream reaches of a riparian stream in central Missouri, USA in the winter of 2008. Hydroclimate stations are located along stream reaches oriented in both cardinal directions, which will allow interpolation of results to other orientations. Each station consists of an array of instrumentation that senses the flux of water and energy into and out of the riparian zone. Reference data are supplied from a nearby flux tower (US DOE) located on top of a forested ridge. The study sites are located within a University of Missouri preserved wildland area on the border of the southern Missouri’s Ozark region, an ecologically distinct region in the central United States. Limestone underlies the study area, resulting in a distinct semi-Karst hydrologic system. Vegetation forms a complex, multi-layered canopy extending from the stream edge through the riparian zone and into surrounding hills. Climate is classified as humid continental, with approximate average annual temperature and precipitation of 13.2°C and 970mm, respectively. Preliminary results (summer 2009 data) indicate incoming short-wave radiation is 24.9% higher at the N-S oriented stream reach relative to the E-W oriented reach. Maximum incoming short wave radiation during the period was 64.5% lower at the N-S reach relative to E-W reach. Average air temperature for the E-W reach was 0.3°C lower

  11. GIS applications in riparian management

    Science.gov (United States)

    Carrie Christman; Douglas W. Shaw; Charles L. Spann; Penny Luehring

    1996-01-01

    GIS was used to prioritize watersheds for treatment needs across the USDA Forest Service Southwestern Region. Factors in this analysis included soil condition, riparian habitat, population centers and mining sites.

  12. Vegetation development following stream/river restoration: more natural fluvial dynamics and morphology, return of aquatic and riparian plant species?

    Science.gov (United States)

    Soons, M. B.

    2012-04-01

    After centuries of human interventions in stream/river dynamics and morphology aimed at optimizing landscapes for agricultural and industrial purposes, new insights have inspired water managers to try and combine stream and river ecosystem functions with the conservation of biodiversity. Around the world, aquatic and riparian species have declined strongly due to pollution, destruction and fragmentation of their habitat, so that biodiversity conservation initiatives primarily focus on habitat restoration. In the past decades many stream and river restoration projects have been carried out and often hydrological dynamics and morphology have been restored to a more natural state. However, the successful restoration of aquatic and riparian habitats very often failed to result in restoration of their biodiversity. This lack of success from a biodiversity conservation perspective is usually attributed to 'dispersal limitation', meaning that the habitat may be restored, but species fail to reach the site and re-colonize it. Especially re-colonization by aquatic and riparian plant species is important, as such species function as ecosystem engineers: their presence alters fluvial dynamics and morphology, generates additional habitat heterogeneity and provides habitat and food for animal species. Following minor disturbances, re-colonization is often possible through locally remaining populations, by seeds in the seed bank or by surviving plant fragments. However, following major disturbances, colonization and establishment from other source populations are necessary. This usually occurs through dispersal of seeds (and in more aquatic species also by dispersal of vegetative fragments) into the restored wetland area. As dispersal occurs predominantly over short distances and source populations of aquatic and riparian species may be lacking in the surroundings, dispersal may be a limiting factor in the development of aquatic and riparian vegetation at a restored site. But

  13. Tree mortality in mature riparian forest: Implications for Fremont cottonwood conservation in the American southwest

    Science.gov (United States)

    Andersen, Douglas

    2015-01-01

    Mature tree mortality rates are poorly documented in desert riparian woodlands. I monitored deaths and calculated annual survivorship probability (Ps) in 2 groups of large (27–114 cm DBH), old (≥40 years old) Fremont cottonwood (Populus fremontii Wats.) in a stand along the free-flowing Yampa River in semiarid northwestern Colorado. Ps = 0.993 year-1 in a group (n = 126) monitored over 2003–2013, whereas Ps = 0.985 year-1 in a group (n = 179) monitored over the same period plus 3 earlier years (2000–2003) that included drought and a defoliating insect outbreak. Assuming Ps was the same for both groups during the 10-year postdrought period, the data indicate that Ps = 0.958 year-1 during the drought. I found no difference in canopy dieback level between male and female survivors. Mortality was equal among size classes, suggesting Ps is independent of age, but published longevity data imply that either Ps eventually declines with age or, as suggested in this study, periods with high Ps are interrupted by episodes of increased mortality. Stochastic population models featuring episodes of low Ps suggest a potential for an abrupt decline in mature tree numbers where recruitment is low. The modeling results have implications for woodland conservation, especially for relictual stands along regulated desert rivers.

  14. Soil water content drives spatiotemporal patterns of CO2 and N2O emissions from a Mediterranean riparian forest soil

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    S. Poblador

    2017-09-01

    Full Text Available Riparian zones play a fundamental role in regulating the amount of carbon (C and nitrogen (N that is exported from catchments. However, C and N removal via soil gaseous pathways can influence local budgets of greenhouse gas (GHG emissions and contribute to climate change. Over a year, we quantified soil effluxes of carbon dioxide (CO2 and nitrous oxide (N2O from a Mediterranean riparian forest in order to understand the role of these ecosystems on catchment GHG emissions. In addition, we evaluated the main soil microbial processes that produce GHG (mineralization, nitrification, and denitrification and how changes in soil properties can modify the GHG production over time and space. Riparian soils emitted larger amounts of CO2 (1.2–10 g C m−2 d−1 than N2O (0.001–0.2 mg N m−2 d−1 to the atmosphere attributed to high respiration and low denitrification rates. Both CO2 and N2O emissions showed a marked (but antagonistic spatial gradient as a result of variations in soil water content across the riparian zone. Deep groundwater tables fueled large soil CO2 effluxes near the hillslope, while N2O emissions were higher in the wet zones adjacent to the stream channel. However, both CO2 and N2O emissions peaked after spring rewetting events, when optimal conditions of soil water content, temperature, and N availability favor microbial respiration, nitrification, and denitrification. Overall, our results highlight the role of water availability on riparian soil biogeochemistry and GHG emissions and suggest that climate change alterations in hydrologic regimes can affect the microbial processes that produce GHG as well as the contribution of these systems to regional and global biogeochemical cycles.

  15. Riparian Forest Buffers - Function for Protection and Enhancement of Water Resources

    Science.gov (United States)

    David J. Welsch

    1991-01-01

    Streamside forests are crucial to the protection and enhancement of the water resources of the Eastern United States. They are extremely complex ecosystems that help provide optimum food and habitat for stream communities as well as being useful in mitigating or controlling nonpoint source pollution (NPS). Used as a component of an integrated management system...

  16. Runoff water quality from a sierran upland forest, transition ecotone, and riparian wet meadow

    Science.gov (United States)

    High concentrations of inorganic N, P, and S have been reported in overland and litter interflow within forested uplands of the Tahoe basin and surrounding watersheds. In this study we compared runoff nutrient concentration and load as well as soil nutrient fluxes at three watershed locations; an up...

  17. Incorporating climate change and exotic species into forecasts of riparian forest distribution.

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    Dana H Ikeda

    Full Text Available We examined the impact climate change (CC will have on the availability of climatically suitable habitat for three native and one exotic riparian species. Due to its increasing prevalence in arid regions throughout the western US, we predicted that an exotic species, Tamarix, would have the greatest increase in suitable habitat relative to native counterparts under CC. We used an ecological niche model to predict range shifts of Populus fremontii, Salix gooddingii, Salix exigua and Tamarix, from present day to 2080s, under five general circulation models and one climate change scenario (A1B. Four major findings emerged. 1 Contrary to our original hypothesis, P. fremontii is projected to have the greatest increase in suitable habitat under CC, followed closely by Tamarix. 2 Of the native species, S. gooddingii and S. exigua showed the greatest loss in predicted suitable habitat due to CC. 3 Nearly 80 percent of future P. fremontii and Salix habitat is predicted to be affected by either CC or Tamarix by the 2080s. 4 By the 2080s, 20 percent of S. gooddingii habitat is projected to be affected by both Tamarix and CC concurrently, followed by S. exigua (19 percent and P. fremontii (13 percent. In summary, while climate change alone will negatively impact both native willow species, Tamarix is likely to affect a larger portion of all three native species' distributions. We discuss these and other results in the context of prioritizing restoration and conservation efforts to optimize future productivity and biodiversity. As we are accounting for only direct effects of CC and Tamarix on native habitat, we present a possible hierarchy of effects- from the direct to the indirect- and discuss the potential for the indirect to outweigh the direct effects. Our results highlight the need to account for simultaneous challenges in the face of CC.

  18. Digital data collection in forest dynamics plots

    Science.gov (United States)

    Faith Inman-Narahari; Christian Giardina; Rebecca Ostertag; Susan Cordell; Lawren Sack

    2010-01-01

    Summary 1. Computers are widely used in all aspects of research but their application to in-field data collection for forest plots has rarely been evaluated. 2. We developed digital data collection methods using ESRI mapping software and ruggedized field computers to map and measure ~30 000 trees in two 4-ha forest dynamics plots in wet and dry...

  19. The Role of Phytodiversity in Riparian Alder Forests in Supporting the Provision of Ecosystem Services

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    Mariničová Patrícia

    2016-11-01

    Full Text Available Nature, ecosystems and biodiversity provide human society with many benefits known as ecosystem services. Functional diversity is an important aspect of biodiversity. In this paper, we applied inductive approach to the identification, mapping and evaluation of ecosystem services of the Aegopodio-Alnetum glutinosae community in Tribeč Mts. The results from 2015 show that the alder floodplain forest represents one of the most productive forest ecosystems with seasonal maximum production of 59.03 g m−2, species diversity of N0 = 40 and functional diversity of FD = 10. The forage potential of this community is medium, the melliferous potential is high and the therapeutic potential was estimated as extremely rich in medicinal plants. From the functional groups for providing ecosystem services, woody plants and hemicryptophytes play the most significant role.

  20. Scaling up and error analysis of transpiration for Populus euphratica in a desert riparian forest

    Science.gov (United States)

    Si, J.; Li, W.; Feng, Q.

    2013-12-01

    Water consumption information of the forest stand is the most important factor for regional water resources management. However, water consumption of individual trees are usually measured based on the limited sample trees , so, it is an important issue how to realize eventual scaling up of data from a series of sample trees to entire stand. Estimation of sap flow flux density (Fd) and stand sapwood area (AS-stand) are among the most critical factors for determining forest stand transpiration using sap flow measurement. To estimate Fd, the various links in sap flow technology have great impact on the measurement of sap flow, to estimate AS-stand, an appropriate indirect technique for measuring each tree sapwood area (AS-tree) is required, because it is impossible to measure the AS-tree of all trees in a forest stand. In this study, Fd was measured in 2 mature P. euphratic trees at several radial depths, 0~10, 10~30mm, using sap flow sensors with the heat ratio method, the relationship model between AS-tree and stem diameter (DBH), growth model of AS-tree were established, using investigative original data of DBH, tree-age, and AS-tree. The results revealed that it can achieve scaling up of transpiration from sample trees to entire forest stand using AS-tree and Fd, however, the transpiration of forest stand (E) will be overvalued by 12.6% if using Fd of 0~10mm, and it will be underestimated by 25.3% if using Fd of 10~30mm, it implied that major uncertainties in mean stand Fd estimations are caused by radial variations in Fd. E will be obviously overvalued when the AS-stand is constant, this result imply that it is the key to improve the prediction accuracy that how to simulate the AS-stand changes in the day scale; They also showed that the potential errors in transpiration with a sample size of approximately ≥30 were almost stable for P.euphrtica, this suggests that to make an allometric equation it might be necessary to sample at least 30 trees.

  1. Cellulose Dynamics during Foliar Litter Decomposition in an Alpine Forest Meta-Ecosystem

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    Kai Yue

    2016-08-01

    Full Text Available To investigate the dynamics and relative drivers of cellulose degradation during litter decomposition, a field experiment was conducted in three individual ecosystems (i.e., forest floor, stream, and riparian zone of an alpine forest meta-ecosystem on the eastern Tibetan Plateau. Four litter species (i.e., willow: Salix paraplesia, azalea: Rhododendron lapponicum, cypress: Sabina saltuaria, and larch: Larix mastersiana that had varying initial litter chemical traits were placed separately in litterbags and then incubated on the soil surface of forest floor plots or in the water of the stream and riparian zone plots. Litterbags were retrieved five times each year during the two-year experiment, with nine replicates each time for each treatment. The results suggested that foliar litter lost 32.2%–89.2% of the initial dry mass depending on litter species and ecosystem type after two-year’s incubation. The cellulose lost 60.1%–96.8% of the initial mass with degradation rate in the order of stream > riparian zone > forest floor. Substantial cellulose degradation occurred at the very beginning (i.e., in the first pre-freezing period of litter decomposition. Litter initial concentrations of phosphorus (P and lignin were found to be the dominant chemical traits controlling cellulose degradation regardless of ecosystems type. The local-scale environmental factors such as temperature, pH, and nutrient availability were important moderators of cellulose degradation rate. Although the effects of common litter chemical traits (e.g., P and lignin concentrations on cellulose degradation across different individual ecosystems were identified, local-scale environmental factors such as temperature and nutrient availability were found to be of great importance for cellulose degradation. These results indicated that local-scale environmental factors should be considered apart from litter quality for generating a reliable predictive framework for the drivers

  2. Functional species traits of carabid beetles living in two riparian alder forests of the Sila plateau subject to different disturbance factors (Coleoptera: Carabidae

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    Antonio Mazzei

    2015-06-01

    Full Text Available We studied carabid beetle assemblages found in riparian black alder forests in the Sila plateau (Southern Apennines. These carabid assemblages are characterized by a high incidence of endemic small-sized, low dispersal, highly stenotopic (hygrophilic, and trophycally specialized species. To evaluate the influence of anthropogenic disturbance on these insects, we compared carabid assemblage of an old undisturbed forest (65-170y, wilderness landscape with that of a younger, partly grazed stand (40-60y, cropland landscape. The carabid assemblage of the disturbed stand was characterized by a higher number of species, but showed a lower incidence of zoophagous specialists and brachypterous beetles, with many species probably coming from an adjacent cropland. However, the disturbed stand maintains almost 80% of the core species found in the older forest, which suggests that these insects are not particularly sensitive to disturbance factors represented by periodic wood harvesting and extensive cattle grazing.

  3. INFLUENCE OF ECOLOGICAL GROUP COMPOSITION, PLANTATION SPACING AND ARRANGEMENT IN THE RESTORATION OF RIPARIAN FOREST ON RESERVOIR SHORES

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    Alvaro Augusto Vieira Soares

    2016-01-01

    Full Text Available This work aimed to assess the effect of spacing, arrangement and ecological group composition of planted seedlings on the restoration process of artificial reservoir shores in southeastern Brazil. The assessments were performed 12 years after the settlement of the experiment in which five mixed stand models were tested. First, a general evaluation of the stand was performed when we surveyed the overstory and understory, seed bank and soil for chemical analysis.Then, the restoration indicators survival of planted trees, basal area and density of the tree community, litter accumulated on the soil and canopy closure index were utilized to compare the plantation models and to assess the influence the experimental factors on these parameters. In the general analysis, we found that the studied stand presents low diversity, poor regeneration, and seed bank dominated mostly by one planted exotic tree species and weeds, which may jeopardize the self- maintenance of the stand in the future. The factor that most influenced the models was the ecological group composition with the best performance found for models in which both pioneer and non-pioneer groups were used. Probably, the plantation arrangement and spacing did not have greater influence due to both plant mortality and natural regeneration that has developed to this age. Hence, it is not recommended the use of only pioneer species in the implantation of riparian forest and the proportion of 50% pioneers and 50% non-pioneers using as much species as possible is indicated for areas that might present constraints for the natural regeneration.

  4. Comparing the Sexual Reproductive Success of Two Exotic Trees Invading Spanish Riparian Forests vs. a Native Reference.

    Science.gov (United States)

    Cabra-Rivas, Isabel; Castro-Díez, Pilar

    2016-01-01

    A widely accepted hypothesis in invasion ecology is that invasive species have higher survival through the early stages of establishment than do non-invasive species. In this study we explore the hypothesis that the sexual reproductive success of the invasive trees Ailanthus altissima (Mill.) Swingle and Robinia pseudoacacia L. is higher than that of the native Fraxinus angustifolia Vahl., all three species coexisting within the riparian forests of Central Spain. We compared different stages of the early life cycle, namely seed rain, seed infestation by insects, seed removal by local fauna, seed germination under optimal conditions and seedling abundance between the two invasive trees and the native, in order to assess their sexual reproductive success. The exotic species did not differ from the native reference (all three species displaying high seed rain and undergoing seed losses up to 50% due to seed removal by the local fauna). Even if the exotic R. pseudoacacia showed a high percentage of empty and insect-parasited seeds along with a low seedling emergence and the exotic A. altissima was the species with more viable seeds and of higher germinability, no differences were found regarding these variables when comparing them with the native F. angustifolia. Unsuitable conditions might have hampered either seedling emergence and survival, as seedling abundance in the field was lower than expected in all species -especially in R. pseudoacacia-. Our results rather suggest that the sexual reproductive success was not higher in the exotic trees than in the native reference, but studies focusing on long-term recruitment would help to shed light on this issue.

  5. Comparing the Sexual Reproductive Success of Two Exotic Trees Invading Spanish Riparian Forests vs. a Native Reference.

    Directory of Open Access Journals (Sweden)

    Isabel Cabra-Rivas

    Full Text Available A widely accepted hypothesis in invasion ecology is that invasive species have higher survival through the early stages of establishment than do non-invasive species. In this study we explore the hypothesis that the sexual reproductive success of the invasive trees Ailanthus altissima (Mill. Swingle and Robinia pseudoacacia L. is higher than that of the native Fraxinus angustifolia Vahl., all three species coexisting within the riparian forests of Central Spain. We compared different stages of the early life cycle, namely seed rain, seed infestation by insects, seed removal by local fauna, seed germination under optimal conditions and seedling abundance between the two invasive trees and the native, in order to assess their sexual reproductive success. The exotic species did not differ from the native reference (all three species displaying high seed rain and undergoing seed losses up to 50% due to seed removal by the local fauna. Even if the exotic R. pseudoacacia showed a high percentage of empty and insect-parasited seeds along with a low seedling emergence and the exotic A. altissima was the species with more viable seeds and of higher germinability, no differences were found regarding these variables when comparing them with the native F. angustifolia. Unsuitable conditions might have hampered either seedling emergence and survival, as seedling abundance in the field was lower than expected in all species -especially in R. pseudoacacia-. Our results rather suggest that the sexual reproductive success was not higher in the exotic trees than in the native reference, but studies focusing on long-term recruitment would help to shed light on this issue.

  6. Biodiversity management approaches for stream-riparian areas: perspectives for Pacific Northwest headwater forests, microclimates, and amphibians.

    Science.gov (United States)

    D.H. Olson; P.D. Anderson; C.A. Frissell; H.H. Welsh; D.F. Bradford

    2007-01-01

    New science insights are redefining stream riparian zones, particularly relative to headwaters, microclimate conditions, and fauna such as amphibians. We synthesize data on these topics, and propose management approaches to target sensitive biota at reach to landscape scales.

  7. Biomass Carbon Sequestration Potential by Riparian Forest in the Tarim River Watershed, Northwest China: Implication for the Mitigation of Climate Change Impact

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    Tayierjiang Aishan

    2018-04-01

    Full Text Available Carbon management in forests has become the most important agenda of the first half of the 21st century in China in the context of the mitigation of climate change impact. As the main producer of the inland river basin ecosystem in arid region of Northwest China, the desert riparian forest maintains the regional environment and also holds a great significance in regulating the regional/global carbon cycle. In this study, we estimated the total biomass, carbon storage, as well as monetary ecosystem service values of desert riparian Populus euphratica Oliv. in the lower reaches of the Tarim River based on terrestrial forest inventory data within an area of 100 ha (100 plots with sizes of 100 m × 100 m and digitized tree data within 1000 ha (with 10 m × 10 m grid using a statistical model of biomass estimation against tree height (TH and diameter at breast height (DBH data. Our results show that total estimated biomass and carbon storage of P. euphratica within the investigated area ranged from 3.00 to 4317.00 kg/ha and from 1.82 to 2158.73 kg/ha, respectively. There was a significant negative relationship (p < 0.001 between biomass productivity of these forests and distance to the river and groundwater level. Large proportions of biomass (64% of total biomass are estimated within 200 m distance to the river where groundwater is relatively favorable for vegetation growth and biomass production. However, our data demonstrated that total biomass showed a sharp decreasing trend with increasing distance to the river; above 800 m distance, less biomass and carbon storage were estimated. The total monetary value of the ecosystem service “carbon storage” provided by P. euphratica was estimated to be $6.8 × 104 USD within the investigated area, while the average monetary value was approximately $70 USD per ha, suggesting that the riparian forest ecosystem in the Tarim River Basin should be considered a relevant regional carbon sink. The findings of

  8. Successional dynamics drive tropical forest nutrient limitation

    Science.gov (United States)

    Chou, C.; Hedin, L. O. O.

    2017-12-01

    It is increasingly recognized that nutrients such as N and P may significantly constrain the land carbon sink. However, we currently lack a complete understanding of these nutrient cycles in forest ecosystems and how to incorporate them into Earth System Models. We have developed a framework of dynamic forest nutrient limitation, focusing on the role of secondary forest succession and canopy gap disturbances as bottlenecks of high plant nutrient demand and limitation. We used succession biomass data to parameterize a simple ecosystem model and examined the dynamics of nutrient limitation throughout tropical secondary forest succession. Due to the patterns of biomass recovery in secondary tropical forests, we found high nutrient demand from rapid biomass accumulation in the earliest years of succession. Depending on previous land use scenarios, soil nutrient availability may also be low in this time period. Coupled together, this is evidence that there may be high biomass nutrient limitation early in succession, which is partially met by abundant symbiotic nitrogen fixation from certain tree species. We predict a switch from nitrogen limitation in early succession to one of three conditions: (i) phosphorus only, (ii) phosphorus plus nitrogen, or (iii) phosphorus, nitrogen, plus light co-limitation. We will discuss the mechanisms that govern the exact trajectory of limitation as forests build biomass. In addition, we used our model to explore scenarios of tropical secondary forest impermanence and the impacts of these dynamics on ecosystem nutrient limitation. We found that secondary forest impermanence exacerbates nutrient limitation and the need for nitrogen fixation early in succession. Together, these results indicate that biomass recovery dynamics early in succession as well as their connection to nutrient demand and limitation are fundamental for understanding and modeling nutrient limitation of the tropical forest carbon sink.

  9. Sediment dynamics in the restored reach of the Kissimmee River Basin, Florida: A vast subtropical riparian wetland

    Science.gov (United States)

    Schenk, E.R.; Hupp, C.R.; Gellis, A.

    2012-01-01

    Historically, the Kissimmee River Basin consisted of a broad nearly annually inundated riparian wetland similar in character to tropical Southern Hemisphere large rivers. The river was channelized in the 1960s and 1970s, draining the wetland. The river is currently being restored with over 10 000 hectares of wetlands being reconnected to 70 river km of naturalized channel. We monitored riparian wetland sediment dynamics between 2007 and 2010 at 87 sites in the restored reach and 14 sites in an unrestored reference reach. Discharge and sediment transport were measured at the downstream end of the restored reach. There were three flooding events during the study, two as annual flood events and a third as a greater than a 5-year flood event. Restoration has returned periodic flood flow to the riparian wetland and provides a mean sedimentation rate of 11.3 mm per year over the study period in the restored reach compared with 1.7 mm per year in an unrestored channelized reach. Sedimentation from the two annual floods was within the normal range for alluvial Coastal Plain rivers. Sediment deposits consisted of over 20% organics, similar to eastern blackwater rivers. The Kissimmee River is unique in North America for its hybrid alluvial/blackwater nature. Fluvial suspended-sediment measurements for the three flood events indicate that a majority of the sediment (70%) was sand, which is important for natural levee construction. Of the total suspended sediment load for the three flood events, 3%–16% was organic and important in floodplain deposition. Sediment yield is similar to low-gradient rivers draining to the Chesapeake Bay and alluvial rivers of the southeastern USA. Continued monitoring should determine whether observed sediment transport and floodplain deposition rates are normal for this river and determine the relationship between historic vegetation community restoration, hydroperiod restoration, and sedimentation.

  10. Structural Dynamics of Tropical Moist Forest Gaps

    Science.gov (United States)

    Hunter, Maria O.; Keller, Michael; Morton, Douglas; Cook, Bruce; Lefsky, Michael; Ducey, Mark; Saleska, Scott; de Oliveira, Raimundo Cosme; Schietti, Juliana

    2015-01-01

    Gap phase dynamics are the dominant mode of forest turnover in tropical forests. However, gap processes are infrequently studied at the landscape scale. Airborne lidar data offer detailed information on three-dimensional forest structure, providing a means to characterize fine-scale (1 m) processes in tropical forests over large areas. Lidar-based estimates of forest structure (top down) differ from traditional field measurements (bottom up), and necessitate clear-cut definitions unencumbered by the wisdom of a field observer. We offer a new definition of a forest gap that is driven by forest dynamics and consistent with precise ranging measurements from airborne lidar data and tall, multi-layered tropical forest structure. We used 1000 ha of multi-temporal lidar data (2008, 2012) at two sites, the Tapajos National Forest and Ducke Reserve, to study gap dynamics in the Brazilian Amazon. Here, we identified dynamic gaps as contiguous areas of significant growth, that correspond to areas > 10 m2, with height gap at Tapajos National Forest (4.8 %) as compared to Ducke Reserve (2.0 %). On average, gaps were smaller at Ducke Reserve and closed slightly more rapidly, with estimated height gains of 1.2 m y-1 versus 1.1 m y-1 at Tapajos. At the Tapajos site, height growth in gap centers was greater than the average height gain in gaps (1.3 m y-1 versus 1.1 m y-1). Rates of height growth between lidar acquisitions reflect the interplay between gap edge mortality, horizontal ingrowth and gap size at the two sites. We estimated that approximately 10 % of gap area closed via horizontal ingrowth at Ducke Reserve as opposed to 6 % at Tapajos National Forest. Height loss (interpreted as repeat damage and/or mortality) and horizontal ingrowth accounted for similar proportions of gap area at Ducke Reserve (13 % and 10 %, respectively). At Tapajos, height loss had a much stronger signal (23 % versus 6 %) within gaps. Both sites demonstrate limited gap contagiousness defined by an

  11. RICHNESS AND FLORISTIC COMPOSITION OF THE FERN COMMUNITY IN RIPARIAN FOREST OF THE RIVER ‘CADEIA’, IN RIO GRANDE DO SUL STATE, BRAZIL

    Directory of Open Access Journals (Sweden)

    Ivanete Teresinha Mallmann

    2014-03-01

    Full Text Available http://dx.doi.org/10.5902/1980509813327The present study analyzed richness and specific composition of the fern community in fragments fromthe riparian forest of river ‘Cadeia’, under different levels of human impact, in Santa Maria do Herval, RioGrande do Sul state, Brazil. An amount of 120 sample units were delimited, equitably distributed in threefragments (FI, II and III in which all species were surveyed and the richness was recorded. The floristiccomposition among fragments was compared using Jaccard’s index and spatial distribution of units wasevaluated through multidimensional scaling. Richness data were presented in the form of rarefaction curvesbased on samples and non-parametric diversity estimators. A total of 40 species were found, belonging to13 families. The greater floristic similarity was between FI and FII. Sample units from FI formed the mostdefined grouping and they had more exclusive species than the others. The rarefaction curve for the totalsampling almost reached the asymptote and estimators indicated a maximum of 45 species, which meansthat the majority of species was surveyed at the study site. A decreasing gradient of mean richness per unitwas observed as the urbanization increased in the matrix habitat of the fragments. These results form a database to be used in management, conservation and reforestation measures in degraded riparian forests. Theycan be directly compared to results from other studies that used rarefaction and richness estimators, whichis not possible to do with many of the surveys accomplished in Brazil so far.

  12. Biodiversity and Phytosociological Studies of Upstream and Downstream Riparian Areas of Pakistan: Special Reference to Taunsa Wildlife Sanctuary and Keti Shah Forests

    International Nuclear Information System (INIS)

    Arfeen, R. Z.; Saleem, A.; Mirza, S. N.; Tayyab, H. M.; Akmal, M.; Afzal, O.

    2015-01-01

    Pakistan riparian zone mostly belongs to Sindh and Punjab provinces and prone to climatic problems and anthropogenic activities. The research was conduct to estimate and compare the structure and composition of riverine floral diversity in low riparian zone of River Indus. The data was collected from Keti Shah forest and Taunsa wildlife sanctuary. Total 14259 plants/individuals were recorded, which belong to 54 plant species with 18 different families. In Taunsa pre-monsoon survey, total 30 plant species were found with 4476 plants from 16 different families. In Taunsa post-monsoon survey total 3348 individuals were recorded from 20 plant species and 9 families. Similarly, in Keti Shah forest, total 3975 individual were recorded from 22 species and 11 families during the pre-monsoon season and 2460 plants were recorded in post-monsoon season, belonging to 16 species and 10 families. These species mostly belong to Fabaceae, Poaceae, Cyperaceae and Asclepiadaceae. Different phytosociological parameters indicate Tamarix dioca, Cynodon dactylon, Desmostachya bipinnata, Imperata cylindrica, Fimbristylis hispidula, Acacia nilotica, Phragmites karka, Tamarix sp. and Saccharum bengalense as dominant species. The biodiversity in upstream and downstream areas were rich in pre-monsoon season in comparison to post-monsoon season in surveyed areas. This study is useful for management of the area in the future as conservation strategies can be made through considering the adaptive tree species in future plantation and endangered species can be conserved. (author)

  13. Large-Scale Mapping of Carbon Stocks in Riparian Forests with Self-Organizing Maps and the k-Nearest-Neighbor Algorithm

    Directory of Open Access Journals (Sweden)

    Leonhard Suchenwirth

    2014-07-01

    Full Text Available Among the machine learning tools being used in recent years for environmental applications such as forestry, self-organizing maps (SOM and the k-nearest neighbor (kNN algorithm have been used successfully. We applied both methods for the mapping of organic carbon (Corg in riparian forests due to their considerably high carbon storage capacity. Despite the importance of floodplains for carbon sequestration, a sufficient scientific foundation for creating large-scale maps showing the spatial Corg distribution is still missing. We estimated organic carbon in a test site in the Danube Floodplain based on RapidEye remote sensing data and additional geodata. Accordingly, carbon distribution maps of vegetation, soil, and total Corg stocks were derived. Results were compared and statistically evaluated with terrestrial survey data for outcomes with pure remote sensing data and for the combination with additional geodata using bias and the Root Mean Square Error (RMSE. Results show that SOM and kNN approaches enable us to reproduce spatial patterns of riparian forest Corg stocks. While vegetation Corg has very high RMSEs, outcomes for soil and total Corg stocks are less biased with a lower RMSE, especially when remote sensing and additional geodata are conjointly applied. SOMs show similar percentages of RMSE to kNN estimations.

  14. Arboreous vegetation of an alluvial riparian forest and their soil relations: Porto Rico island, Paraná river, Brazil

    Directory of Open Access Journals (Sweden)

    Campos João Batista

    2002-01-01

    Full Text Available The dynamics of alluvial deposits in floodplains forms islands and sandbanks. Deposits frequently accumulate at the river margins and on islands with consequent side growths. One of these sandbanks which started to form in 1952 annexed an area of 12.4ha to the Porto Rico island (53masculine15?W and 22masculine45?S. At present a forest fragment of approximately 2.0 ha exists in this place. The structural analysis of arboreous vegetation of this fragment showed a floristic gradient related to the physical and chemical variations of the substratum. High density of pioneer species associated to the absence of recruitment of new individuals of these and other successional categories indicated that the forest was impaired in its succession process. This fact could be associated with constant disturbances caused by cattle in the area.

  15. Light habitat, structure, diversity and dynamic of the tropical dry forest

    Directory of Open Access Journals (Sweden)

    Omar Melo-Cruz

    2017-01-01

    Full Text Available Tropical dry forests are complex and fragile ecosystems with high anthropic intervention and restricted reproductive cycles. These have unique richness, structural diversity, physiological and phenological . This research was executed  in the Upper Magdalena Valley, in four forest fragments with different successional stages. In each fragment four permanent plots of 0.25 ha were established and lighting habitat associated with richness, relative abundance and rarity of species. The forest dynamics included the mortality, recruitment and diameter growth for a period of 5.25 years. The species rischness found in the mature riparian forestis higher than that reported in other studies of similar areas in Valle del Cauca and the Atlantic coast.  The values of richness, diversity and rarity species are more evidenced  than the magnitudes found in  drier areas of Tolima. The structure, diversity and dynamics of forests were correlated with the lighting habitat, showing differences in canopy architecture and its role in the capture and absorption of radiation. Forests with dense canopy have limited availability of photosynthetically active radiation in understory related low species richness, while illuminated undergrowth are richer and heterogeneous.

  16. Riparian Inventory

    Data.gov (United States)

    Kansas Data Access and Support Center — This dataset is a digital representation of the 1:24,000 Land Use Riparian Areas Inventory for the state of Kansas. The dataset includes a 100 foot buffer around all...

  17. Perceptions of environmental change and use of traditional knowledge to plan riparian forest restoration with relocated communities in Alcântara, Eastern Amazon.

    Science.gov (United States)

    Celentano, Danielle; Rousseau, Guillaume Xavier; Engel, Vera Lex; Façanha, Cristiane Lima; Oliveira, Elivaldo Moreira de; Moura, Emanoel Gomes de

    2014-01-27

    Riparian forests provide ecosystem services that are essential for human well-being. The Pepital River is the main water supply for Alcântara (Brazil) and its forests are disappearing. This is affecting water volume and distribution in the region. Promoting forest restoration is imperative. In deprived regions, restoration success depends on the integration of ecology, livelihoods and traditional knowledge (TEK). In this study, an interdisciplinary research framework is proposed to design riparian forest restoration strategies based on ecological data, TEK and social needs. This study takes place in a region presenting a complex history of human relocation and land tenure. Local populations from seven villages were surveyed to document livelihood (including 'free-listing' of agricultural crops and homegarden tree species). Additionally, their perceptions toward environmental changes were explored through semi-structured interviews (n = 79). Ethnobotanical information on forest species and their uses were assessed by local-specialists (n = 19). Remnants of conserved forests were surveyed to access ecological information on tree species (three plots of 1,000 m2). Results included descriptive statistics, frequency and Smith’s index of salience of the free-list results. The local population depends primarily on slash-and-burn subsistence agriculture to meet their needs. Interviewees showed a strong empirical knowledge about the environmental problems of the river, and of their causes, consequences and potential solutions. Twenty-four tree species (dbh > 10 cm) were found at the reference sites. Tree density averaged 510 individuals per hectare (stdv = 91.6); and 12 species were considered the most abundant (density > 10ind/ha). There was a strong consensus among plant-specialists about the most important trees. The species lists from reference sites and plant-specialists presented an important convergence. Slash-and-burn agriculture is the main source of livelihood

  18. Tree mortality in response to typhoon-induced floods and mudslides is determined by tree species, size, and position in a riparian Formosan gum forest in subtropical Taiwan.

    Science.gov (United States)

    Tzeng, Hsy-Yu; Wang, Wei; Tseng, Yen-Hsueh; Chiu, Ching-An; Kuo, Chu-Chia; Tsai, Shang-Te

    2018-01-01

    Global warming-induced extreme climatic changes have increased the frequency of severe typhoons bringing heavy rains; this has considerably affected the stability of the forest ecosystems. Since the Taiwan 921 earthquake occurred in 21 September 1999, the mountain geology of the Island of Taiwan has become unstable and typhoon-induced floods and mudslides have changed the topography and geomorphology of the area; this has further affected the stability and functions of the riparian ecosystem. In this study, the vegetation of the unique Aowanda Formosan gum forest in Central Taiwan was monitored for 3 years after the occurrence of floods and mudslides during 2009-2011. Tree growth and survival, effects of floods and mudslides, and factors influencing tree survival were investigated. We hypothesized that (1) the effects of floods on the survival are significantly different for each tree species; (2) tree diameter at breast height (DBH) affects tree survival-i.e., the larger the DBH, the higher the survival rate; and (3) the relative position of trees affects tree survival after disturbances by floods and mudslides-the farther trees are from the river, the higher is their survival rate. Our results showed that after floods and mudslides, the lifespans of the major tree species varied significantly. Liquidambar formosana displayed the highest flood tolerance, and the trunks of Lagerstoemia subcostata began rooting after disturbances. Multiple regression analysis indicated that factors such as species, DBH, distance from sampled tree to the above boundary of sample plot (far from the riverbank), and distance from the upstream of the river affected the lifespans of trees; the three factors affected each tree species to different degrees. Furthermore, we showed that insect infestation had a critical role in determining tree survival rate. Our 3-year monitoring investigation revealed that severe typhoon-induced floods and mudslides disturbed the riparian vegetation in the

  19. Tree mortality in response to typhoon-induced floods and mudslides is determined by tree species, size, and position in a riparian Formosan gum forest in subtropical Taiwan

    Science.gov (United States)

    Tzeng, Hsy-Yu; Wang, Wei; Tseng, Yen-Hsueh; Chiu, Ching-An; Kuo, Chu-Chia

    2018-01-01

    Global warming-induced extreme climatic changes have increased the frequency of severe typhoons bringing heavy rains; this has considerably affected the stability of the forest ecosystems. Since the Taiwan 921 earthquake occurred in 21 September 1999, the mountain geology of the Island of Taiwan has become unstable and typhoon-induced floods and mudslides have changed the topography and geomorphology of the area; this has further affected the stability and functions of the riparian ecosystem. In this study, the vegetation of the unique Aowanda Formosan gum forest in Central Taiwan was monitored for 3 years after the occurrence of floods and mudslides during 2009–2011. Tree growth and survival, effects of floods and mudslides, and factors influencing tree survival were investigated. We hypothesized that (1) the effects of floods on the survival are significantly different for each tree species; (2) tree diameter at breast height (DBH) affects tree survival–i.e., the larger the DBH, the higher the survival rate; and (3) the relative position of trees affects tree survival after disturbances by floods and mudslides–the farther trees are from the river, the higher is their survival rate. Our results showed that after floods and mudslides, the lifespans of the major tree species varied significantly. Liquidambar formosana displayed the highest flood tolerance, and the trunks of Lagerstoemia subcostata began rooting after disturbances. Multiple regression analysis indicated that factors such as species, DBH, distance from sampled tree to the above boundary of sample plot (far from the riverbank), and distance from the upstream of the river affected the lifespans of trees; the three factors affected each tree species to different degrees. Furthermore, we showed that insect infestation had a critical role in determining tree survival rate. Our 3-year monitoring investigation revealed that severe typhoon-induced floods and mudslides disturbed the riparian vegetation

  20. Faster Fully-Dynamic minimum spanning forest

    DEFF Research Database (Denmark)

    Holm, Jacob; Rotenberg, Eva; Wulff-Nilsen, Christian

    2015-01-01

    We give a new data structure for the fully-dynamic minimum spanning forest problem in simple graphs. Edge updates are supported in O(log4 n/log logn) expected amortized time per operation, improving the O(log4 n) amortized bound of Holm et al. (STOC’98, JACM’01).We also provide a deterministic data...

  1. Forecast for the dynamics of forests in Krasnoyarsk Krai

    Directory of Open Access Journals (Sweden)

    V. A. Sokolov

    2017-08-01

    Full Text Available Dynamics of the forest ecosystems connects closely with the natural and anthropogenic changes (succession processes, forest fires, windfalls, forest insects, forest diseases, forest harvesting, reforestation, the infrastructure development associated and not associated with forestry and so forth. Authors do not consider the up-to-day problem of global warming on the Earth, as opinions of scientists are controversial. Retrospective analysis of forest dynamics of the Krasnoyarsk Territory for the last 50 years has allowed to assess the impact of these changes on condition of forests. The univocal conclusion of deterioration of forest quality has been drawn. Area of coniferous forests has decreased by 9 %, including the 25 % reduction of mature and overmature forest stands. To forecast forest dynamics, modelling of natural and anthropogenic processes in the forest ecosystems has been applied, taking into account that the existing system of measures for reforestation and tending care of forest actually does not affect dynamics of the forests. The provision about increase in forest harvesting volume to 37.6 million м3 of the Development Strategy of the Krasnoyarsk Forest Industrial Complex has been used for forecasting. It has been proved that such scale of forest harvesting will inevitably lead to the over-cutting of ecological and economic accessible allowable cut that will negatively affect the forest condition in 50 years. Our forecast of forest dynamics of the Krasnoyarsk Territory for the next 50 years has showed that negative changes will continue at the same pace under the current extensive form of forest management. What is more, the maximum decrease of forest area might be in pine forests (32.9 % with the significant increase of broadleaves forests – 22.7 %. To improve the situation in the Russian forest sector, a radical change in the system of forest management is needed.

  2. Survey of vegetation and its diametric distribution in an area of cerrado sensu stricto and riparian forest fragment at Dois Irmãos stream in the Area of Environmental Protection (APA of Cafuringa, Federal District, Brazil.

    Directory of Open Access Journals (Sweden)

    José Elias de Paula

    2009-09-01

    Full Text Available All individual trees with a diameter at breast height (DBH of over 5cm, as well as the natural succession, were identified in 2,500m2 of the savannah (cerrado sensu stricto area and in 5,000m2 of the “Dois Irmãos” riparian forest vegetation (15º30’19”S and 48º06’18”W. The floristic composition of the cerrado sensu stricto was composed by 100 trees distributed in 25 species, and the riparian forest consisted of 155 trees distributed in 55 species. The natural regeneration was formed with 211 and 287 individuals in the cerrado sensu stricto and riparian forest distributed into 38 and 55 species respectively. The basal areas of the trees occupied 3.40m2.ha-1 in the cerrado sensu stricto and 5.08m2.ha-1 in the riparian forest. The diametric distribution curves for both plant communities, adjusted by the Meyers equation, demonstrated a typical tendency of reversed-J shape with strongly antropic action in the 11 to 17cm diametric classes.

  3. Stream water responses to timber harvest: Riparian buffer width effectiveness

    Science.gov (United States)

    Barton D. Clinton

    2011-01-01

    Vegetated riparian buffers are critical for protecting aquatic and terrestrial processes and habitats in southern Appalachian ecosystems. In this case study, we examined the effect of riparian buffer width on stream water quality following upland forest management activities in four headwater catchments. Three riparian buffer widths were delineated prior to cutting; 0m...

  4. Dynamics of radionuclides in forest ecosystems

    International Nuclear Information System (INIS)

    Steiner, M.

    2004-01-01

    The unique physiology and the layered structure of forest ecosystems result in dynamic transport and transfer processes which greatly differ from those in agricultural ecosystems. Radionuclides are retained in the upper organic horizons of forest soil for several decades and remain highly available for uptake by fungi and green plants. Contamination levels of mushrooms and game may therefore by far exceed those of agricultural produce. The efficient cycling of nutrients and radionuclides, which is characteristic for ecosystems poor in nutrients, can largely be attributed to forest soil with its complex and multi-layered structure and fungal activity. Fungi directly affect dynamic processes, playing a key role in the mobilization, uptake and translocation of nutrients and radionuclides. Fungal fruit bodies may be highly contaminated foodstuff and fodder. They are most likely the cause of the surprising trend of increasing contamination of wild boar which has been observed in the last few years in Germany. This paper is intended to give a qualitative survey of dynamic transport processes in forests and their relevance for radiation exposure to man. (orig.)

  5. Methane emission in a specific riparian-zone sediment decreased with bioelectrochemical manipulation and corresponded to the microbial community dynamics

    Directory of Open Access Journals (Sweden)

    Elliot S. Friedman

    2016-01-01

    Full Text Available Dissimilatory metal-reducing bacteria are widespread in terrestrial ecosystems, especially in anaerobic soils and sediments. Thermodynamically, dissimilatory metal reduction is more favorable than sulfate reduction and methanogenesis but less favorable than denitrification and aerobic respiration. It is critical to understand the complex relationships, including the absence or presence of terminal electron acceptors, that govern microbial competition and coexistence in anaerobic soils and sediments, because subsurface microbial processes can effect greenhouse gas emissions from soils, possibly resulting in impacts at the global scale. Here, we elucidated the effect of an inexhaustible, ferrous-iron and humic-substance mimicking terminal electron acceptor by deploying potentiostatically poised electrodes in the sediment of a very specific stream riparian zone in Upstate New York state. At two sites within the same stream riparian zone during the course of six weeks in the spring of 2013, we measured CH4 and N2/N2O emissions from soil chambers containing either poised or unpoised electrodes, and we harvested biofilms from the electrodes to quantify microbial community dynamics. At the upstream site, which had a lower vegetation cover and highest soil temperatures, the poised electrodes inhibited CH4 emissions by ~45% (when normalized to remove temporal effects. CH4 emissions were not significantly impacted at the downstream site. N2/N2O emissions were generally low at both sites and were not impacted by poised electrodes. We did not find a direct link between bioelectrochemical treatment and microbial community membership; however, we did find a correspondence between environment/function and microbial community dynamics.

  6. Avian diversity and feeding guilds in a secondary forest, an oil palm plantation and a paddy field in riparian areas of the kerian river basin, perak, malaysia.

    Science.gov (United States)

    Azman, Nur Munira; Latip, Nurul Salmi Abdul; Sah, Shahrul Anuar Mohd; Akil, Mohd Abdul Muin Md; Shafie, Nur Juliani; Khairuddin, Nurul Liyana

    2011-12-01

    The diversity and the feeding guilds of birds in three different habitats (secondary forest, oil palm plantation and paddy field) were investigated in riparian areas of the Kerian River Basin (KRB), Perak, Malaysia. Point-count observation and mist-netting methods were used to determine bird diversity and abundance. A total of 132 species of birds from 46 families were recorded in the 3 habitats. Species diversity, measured by Shannon's diversity index, was 3.561, 3.183 and 1.042 in the secondary forest, the paddy field and the oil palm plantation, respectively. The vegetation diversity and the habitat structure were important determinants of the number of bird species occurring in an area. The relative abundance of the insectivore, insectivore-frugivore and frugivore guilds was greater in the forest than in the monoculture plantation. In contrast, the relative abundance of the carnivore, granivore and omnivore guilds was higher in the plantation. The results of the study show that the conversion of forest to either oil palm plantation or paddy fields produced a decline in bird diversity and changes in the distribution of bird feeding guilds.

  7. A Regional Guidebook for Conducting Functional Assessments of Forested Wetlands and Riparian Areas in the Ozark Mountains Region of Arkansas

    Science.gov (United States)

    2008-09-01

    declines in the black bear and Florida panther . The extent to which patch size affects animal populations has been most thoroughly investi- gated with... animal communities. Reservoir construction and agricultural practices have eliminated or severely degraded many of the wetlands and riparian areas...oak (Q. falcata), and black oak (Q. velutina), and a variety of hickories, including mockernut (Carya tomentosa), pignut (C. glabra), and shagbark

  8. Dynamic conservation of forest genetic resources in 33 European countries

    NARCIS (Netherlands)

    Lefevre, F.; Koskela, J.; Hubert, J.; Kraigher, H.; Longauer, R.; Olrik, D.C.; Vries, de S.M.G.

    2013-01-01

    Dynamic conservation of forest genetic resources (FGR) means maintaining the genetic diversity of trees within an evolutionary process and allowing generation turnover in the forest. We assessed the network of forests areas managed for the dynamic conservation of FGR (conservation units) across

  9. Monitoring U.S. forest dynamics with Landsat [Chapter 12

    Science.gov (United States)

    Jeffrey G. Masek; Sean P. Healey

    2012-01-01

    Forest dynamics in the United States differ substantially from those in the developing world and thus present unique monitoring requirements. While deforestation and conversion to semipermanent agriculture dominate tropical forest dynamics, the area of forest land in the United States has remained fairly constant for the last 50-60 years (Birdsey and Lewis 2003)....

  10. Riparian responses to extreme climate and land-use change scenarios.

    Science.gov (United States)

    Fernandes, Maria Rosário; Segurado, Pedro; Jauch, Eduardo; Ferreira, Maria Teresa

    2016-11-01

    Climate change will induce alterations in the hydrological and landscape patterns with effects on riparian ecotones. In this study we assess the combined effect of an extreme climate and land-use change scenario on riparian woody structure and how this will translate into a future risk of riparian functionality loss. The study was conducted in the Tâmega catchment of the Douro basin. Boosted Regression Trees (BRTs) were used to model two riparian landscape indicators related with the degree of connectivity (Mean Width) and complexity (Area Weighted Mean Patch Fractal Dimension). Riparian data were extracted by planimetric analysis of high spatial-resolution Word Imagery Layer (ESRI). Hydrological, climatic and land-use variables were obtained from available datasets and generated with process-based modeling using current climate data (2008-2014), while also considering the high-end RCP8.5 climate-change and "Icarus" socio-economic scenarios for the 2046-2065 time slice. Our results show that hydrological and land-use changes strongly influence future projections of riparian connectivity and complexity, albeit to diverse degrees and with differing effects. A harsh reduction in average flows may impair riparian zones while an increase in extreme rain events may benefit connectivity by promoting hydrologic dynamics with the surrounding floodplains. The expected increase in broad-leaved woodlands and mixed forests may enhance the riparian galleries by reducing the agricultural pressure on the area in the vicinity of the river. According to our results, 63% of river segments in the Tâmega basin exhibited a moderate risk of functionality loss, 16% a high risk, and 21% no risk. Weaknesses and strengths of the method are highlighted and results are discussed based on a resilience perspective with regard to riparian ecosystems. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. The dynamics of radionuclides in forest ecosystems

    International Nuclear Information System (INIS)

    Steiner, M.

    2003-01-01

    Foodstuff from forests, notably mushrooms and game, is still much higher contaminated than agricultural products. The dynamic transport and transfer processes relevant to radiocesium in forest ecosystems will be discussed. Fungi, notably their mycelia, and migration processes in forest soil play a key role. In the first phase after deposition, radiocesium is very mobile and infiltrates forest soil after direct deposition or weathering from the canopy, where it is quickly immobilized. Subsequently, it moves to deeper soil layers due to decomposition and mineralization of organic matter. This downward migration of radiocesium is almost completely compensated by an upward transport in fungal mycelia. Whereas the specific activities in the uppermost organic horizons decrease comparatively fast, the radiocesium content in deeper horizons may remain almost constant or even increase at the beginning. Fungi which specific to their species take up nutrients from different soil layers, reflect the different trends with time in their fruit bodies. Fungal mycelia play an important role not only in the vertical migration, but also in the horizontal transport of radiocesium in forest soil and the uptake by green plants. Most green plants of the forest ecosystem poor in nutrients take up nutrients and radiocesium through symbiotic fungi. The fruit bodies of Deer Truffle which grow below ground can exhibit activity levels one order of magnitude higher than those of edible mushrooms. At present there is a debate, whether highly contaminated Deer Truffle eaten by wild boar as a delicacy, can explain the trend of increasing contamination of wild boar which has been observed in the last few years in different regions of Germany. (orig.)

  12. Forest structure and carbon dynamics in Amazonian tropical rain forests.

    Science.gov (United States)

    Vieira, Simone; de Camargo, Plinio Barbosa; Selhorst, Diogo; da Silva, Roseana; Hutyra, Lucy; Chambers, Jeffrey Q; Brown, I Foster; Higuchi, Niro; dos Santos, Joaquim; Wofsy, Steven C; Trumbore, Susan E; Martinelli, Luiz Antonio

    2004-08-01

    Living trees constitute one of the major stocks of carbon in tropical forests. A better understanding of variations in the dynamics and structure of tropical forests is necessary for predicting the potential for these ecosystems to lose or store carbon, and for understanding how they recover from disturbance. Amazonian tropical forests occur over a vast area that encompasses differences in topography, climate, and geologic substrate. We observed large differences in forest structure, biomass, and tree growth rates in permanent plots situated in the eastern (near Santarém, Pará), central (near Manaus, Amazonas) and southwestern (near Rio Branco, Acre) Amazon, which differed in dry season length, as well as other factors. Forests at the two sites experiencing longer dry seasons, near Rio Branco and Santarém, had lower stem frequencies (460 and 466 ha(-1) respectively), less biodiversity (Shannon-Wiener diversity index), and smaller aboveground C stocks (140.6 and 122.1 Mg C ha(-1)) than the Manaus site (626 trees ha(-1), 180.1 Mg C ha(-1)), which had less seasonal variation in rainfall. The forests experiencing longer dry seasons also stored a greater proportion of the total biomass in trees with >50 cm diameter (41-45 vs 30% in Manaus). Rates of annual addition of C to living trees calculated from monthly dendrometer band measurements were 1.9 (Manaus), 2.8 (Santarém), and 2.6 (Rio Branco) Mg C ha(-1) year(-1). At all sites, trees in the 10-30 cm diameter class accounted for the highest proportion of annual growth (38, 55 and 56% in Manaus, Rio Branco and Santarém, respectively). Growth showed marked seasonality, with largest stem diameter increment in the wet season and smallest in the dry season, though this may be confounded by seasonal variation in wood water content. Year-to-year variations in C allocated to stem growth ranged from nearly zero in Rio Branco, to 0.8 Mg C ha(-1) year(-1) in Manaus (40% of annual mean) and 0.9 Mg C ha(-1) year(-1) (33% of

  13. Snowmelt induced hydrologic perturbations drive dynamic microbiological and geochemical behaviors across a shallow riparian aquifer

    Directory of Open Access Journals (Sweden)

    Robert eDanczak

    2016-05-01

    Full Text Available Shallow riparian aquifers represent hotspots of biogeochemical activity in the arid western US. While these environments provide extensive ecosystem services, little is known of how natural environmental perturbations influence subsurface microbial communities and associated biogeochemical processes. Over a six-month period we tracked the annual snowmelt-driven incursion of groundwater into the vadose zone of an aquifer adjacent to the Colorado River, leading to increased dissolved oxygen (DO concentrations in the normally suboxic saturated zone. Strong biogeochemical heterogeneity was measured across the site, with abiotic reactions between DO and sulfide minerals driving rapid DO consumption and mobilization of redox active species in reduced aquifer regions. Conversely, extensive DO increases were detected in less reduced sediments. 16S rRNA gene surveys tracked microbial community composition within the aquifer, revealing strong correlations between increases in putative oxygen-utilizing chemolithoautotrophs and heterotrophs and rising DO concentrations. The gradual return to suboxic aquifer conditions favored increasing abundances of 16S rRNA sequences matching members of the Microgenomates (OP11 and Parcubacteria (OD1 that have been strongly implicated in fermentative processes. Microbial community stability measurements indicated that deeper aquifer locations were relatively less affected by geochemical perturbations, while communities in shallower locations exhibited the greatest change. Reactive transport modeling of the geochemical and microbiological results supported field observations, suggesting that a predictive framework can be applied to develop a greater understanding of such environments.

  14. Snowmelt induced hydrologic perturbations drive dynamic microbiological and geochemical behaviors across a shallow riparian aquifer

    Science.gov (United States)

    Danczak, Robert; Yabusaki, Steven; Williams, Kenneth; Fang, Yilin; Hobson, Chad; Wilkins, Michael

    2016-05-01

    Shallow riparian aquifers represent hotspots of biogeochemical activity in the arid western US. While these environments provide extensive ecosystem services, little is known of how natural environmental perturbations influence subsurface microbial communities and associated biogeochemical processes. Over a six-month period we tracked the annual snowmelt-driven incursion of groundwater into the vadose zone of an aquifer adjacent to the Colorado River, leading to increased dissolved oxygen (DO) concentrations in the normally suboxic saturated zone. Strong biogeochemical heterogeneity was measured across the site, with abiotic reactions between DO and sulfide minerals driving rapid DO consumption and mobilization of redox active species in reduced aquifer regions. Conversely, extensive DO increases were detected in less reduced sediments. 16S rRNA gene surveys tracked microbial community composition within the aquifer, revealing strong correlations between increases in putative oxygen-utilizing chemolithoautotrophs and heterotrophs and rising DO concentrations. The gradual return to suboxic aquifer conditions favored increasing abundances of 16S rRNA sequences matching members of the Microgenomates (OP11) and Parcubacteria (OD1) that have been strongly implicated in fermentative processes. Microbial community stability measurements indicated that deeper aquifer locations were relatively less affected by geochemical perturbations, while communities in shallower locations exhibited the greatest change. Reactive transport modeling of the geochemical and microbiological results supported field observations, suggesting that a predictive framework can be applied to develop a greater understanding of such environments.

  15. Modeling the Effects of Hydrogeomorphology and Climactic Factors on Nitrogen, Phosphorus, and Greenhouse Gas Dynamics in Riparian Zones.

    Science.gov (United States)

    Hassanzadeh, Y.; Vidon, P.; Gold, A.; Pradhanang, S. M.; Addy, K.

    2017-12-01

    Vegetated riparian zones are often considered for use as best management practices to mitigate the impacts of agriculture on water quality. However, riparian zones can also be a source of greenhouse gases and their influence on water quality varies depending on landscape hydrogeomorphic characteristics and climate. Methods used to evaluate riparian zone functions include conceptual models, and spatially explicit and process based models (REMM), but very few attempts have been made to connect riparian zone characteristics with function using easily accessible landscape scale data. Here, we present comprehensive statistical models that can be used to assess riparian zone functions with easily obtainable landscape-scale hydrogeomorphic attributes and climate data. Models were developed from a database spanning 88 years and 36 sites. Statistical methods including principal component analysis and stepwise regression were used to reduced data dimensionality and identify significant predictors. Models were validated using additional data collected from scientific literature. The 8 models developed connect landscape characteristics to nitrogen and phosphorus concentration and removal (1-4), greenhouse gas emissions (5-7), and water table depth (8). Results show the range of influence that various climate and landscape characteristics have on riparian zone functions, and the tradeoffs that exist with regards to nitrogen, phosphorous, and greenhouse gases. These models will help reduce the need for extensive field measurements and help scientists and land managers make more informed decisions regarding the use of riparian zones for water quality management.

  16. Crepuscular activity of culicids (Diptera, Culicidae in the peridomicile and in the remaining riparian forest in Tibagi river, State of Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Gerson A. Müller

    2012-03-01

    Full Text Available Crepuscular activity of culicids (Diptera, Culicidae in the peridomicile and in the remaining riparian forest in Tibagi river, State of Paraná, Brazil. Human-attracted mosquitoes were collected for one hour, around sunset time (half hour before and half after, from April to December 2006, in two environments (riparian forest and near houses, in Tibagi river basin, Palmeira municipality, State of Paraná. Seven-hundred forty-nine mosquitoes, belonging to 13 species, were collected. Psorophora champerico Dyar & Knab, 1906 (42.86% and Psorophora discrucians (Walker, 1856 (40.59% were the most frequent species. No significant differences between quantities of Ps. champerico (t = -0.792; d.f. = 16; p = 0.43 and Ps. discrucians (t = 0.689; d.f. = 16; p = 0.49 obtained in riparian forest and near houses were observed, indicating similar conditions for crepuscular activity of these species in both environments. Psorophora champerico and Ps. discrucians responded (haematophagic activity to environmental stimuli associated with the twilight hours differently in distinct habitats studied. The former species is registered for the first time in the Atlantic forest biome.Atividade crepuscular de culicídeos (Diptera, Culicidae no peridomicílio e remanescentes de matas ciliares do Rio Tibagi. Estado do Paraná, Brasil. Mosquitos atraídos por humanos foram coletados por uma hora em torno do crepúsculo vespertino (meia hora antes e meia hora depois, de abril a dezembro de 2006, em dois locais (mata ciliar e peridomicílio na bacia do Rio Tibagi, município de Palmeira, Estado do Paraná. Foram capturados 749 mosquitos distribuídos em 13 espécies. Psorophora champerico Dyar & Knab, 1906 (42,86% e Ps. discrucians (Walker, 1856 (40,59% foram as espécies mais freqüentes. Não foram registradas diferenças significativas entre as médias de indivíduos capturados entre os pontos de mata ciliar e peridomicílio para Ps. champerico (t = -0,792; g.l. = 16; p = 0

  17. ANALYSIS OF GROWTH AND GAS EXCHANGE OF PLANTS Lonchocarpus sericeus (Poir. D.C. IN FLOODING FOR THE RECOVERY OF THE RIPARIAN FORESTS

    Directory of Open Access Journals (Sweden)

    Jean Marcel Sousa Lira

    2013-12-01

    Full Text Available http://dx.doi.org/10.5902/1980509812349In order to select species for using in the restoration of riparian forests on the banks of the Sao FranciscoRiver, in the state of Sergipe, an experiment was conducted to evaluate the growth and gas exchange ofplants Lonchocarpus sericeus (Poir. D.C., subject to flooding conditions in the nursery. The experimentwas conducted at Forest Nursery, Department of Forest Sciences, Federal University of Sergipe (UFS,the municipality of São Cristóvão, (11 º 01 'S latitude and 37 º 12' longitude W, altitude 20 m , stateof Sergipe, Brazil, from October 2006 to January 2007 under ambient conditions. We used a completelyrandomized design (CRD, factorial (2x7, two treatments (control - T0, plants at field capacity and flooded- T1 and days after flooding (0, 15, 30, 45, 60, 75 and 90 days. To simulate the condition of flooding,the plants were placed in plastic pots of black color with a volume of 5 L and more substrate. Followingthese pots were attached to pots with a volume of 10 L, which was added water until it reaches a waterdepth of 5 cm above the top of the plants. The control plants kept in pots with a volume of 5 L substratemaintained at field capacity. In non-destructive variables were used four replicates per treatment evaluatedevery fifteen days, where each replicate consists of six plants, totaling 24. Destructive variables used were4 replicates per treatment, determined biweekly from 15 days after flooding, where each replicate consistsof a plant totaling 24 plants. Therefore, 48 plants were used per treatment. The non-destructive variableswere height, diameter and number of leaves. While the destructive variables analyzed were dry weight ofroots, dry weight of shoots and dry weight of root / shoot ratio. In addition, we carried out analysis of gasexchange on a monthly basis and evaluated twelve plants per treatment, with two sampling leaves, fullyexpanded, per plant. The biometric variables were

  18. Animal water balance drives top-down effects in a riparian forest-implications for terrestrial trophic cascades.

    Science.gov (United States)

    McCluney, Kevin E; Sabo, John L

    2016-08-17

    Despite the clear importance of water balance to the evolution of terrestrial life, much remains unknown about the effects of animal water balance on food webs. Based on recent research suggesting animal water imbalance can increase trophic interaction strengths in cages, we hypothesized that water availability could drive top-down effects in open environments, influencing the occurrence of trophic cascades. We manipulated large spider abundance and water availability in 20 × 20 m open-air plots in a streamside forest in Arizona, USA, and measured changes in cricket and small spider abundance and leaf damage. As expected, large spiders reduced both cricket abundance and herbivory under ambient, dry conditions, but not where free water was added. When water was added (free or within moist leaves), cricket abundance was unaffected by large spiders, but spiders still altered herbivory, suggesting behavioural effects. Moreover, we found threshold-type increases in herbivory at moderately low soil moisture (between 5.5% and 7% by volume), suggesting the possibility that water balance may commonly influence top-down effects. Overall, our results point towards animal water balance as an important driver of direct and indirect species interactions and food web dynamics in terrestrial ecosystems. © 2016 The Author(s).

  19. Geography of Global Forest Carbon Stocks & Dynamics

    Science.gov (United States)

    Saatchi, S. S.; Yu, Y.; Xu, L.; Yang, Y.; Fore, A.; Ganguly, S.; Nemani, R. R.; Zhang, G.; Lefsky, M. A.; Sun, G.; Woodall, C. W.; Naesset, E.; Seibt, U. H.

    2014-12-01

    Spatially explicit distribution of carbon stocks and dynamics in global forests can greatly reduce the uncertainty in the terrestrial portion of the global carbon cycle by improving estimates of emissions and uptakes from land use activities, and help with green house gas inventory at regional and national scales. Here, we produce the first global distribution of carbon stocks in living woody biomass at ~ 100 m (1-ha) resolution for circa 2005 from a combination of satellite observations and ground inventory data. The total carbon stored in live woody biomass is estimated to be 337 PgC with 258 PgC in aboveground and 79 PgC in roots, and partitioned globally in boreal (20%), tropical evergreen (50%), temperate (12%), and woodland savanna and shrublands (15%). We use a combination of satellite observations of tree height, remote sensing data on deforestation and degradation to quantify the dynamics of these forests at the biome level globally and provide geographical distribution of carbon storage dynamics in terms sinks and sources globally.

  20. Plant litter dynamics in the forest-stream interface: precipitation is a major control across tropical biomes.

    Science.gov (United States)

    Tonin, Alan M; Gonçalves, José F; Bambi, Paulino; Couceiro, Sheyla R M; Feitoza, Lorrane A M; Fontana, Lucas E; Hamada, Neusa; Hepp, Luiz U; Lezan-Kowalczuk, Vânia G; Leite, Gustavo F M; Lemes-Silva, Aurea L; Lisboa, Leonardo K; Loureiro, Rafael C; Martins, Renato T; Medeiros, Adriana O; Morais, Paula B; Moretto, Yara; Oliveria, Patrícia C A; Pereira, Evelyn B; Ferreira, Lidiane P; Pérez, Javier; Petrucio, Mauricio M; Reis, Deusiano F; S Rezende, Renan; Roque, Nadia; Santos, Luiz E P; Siegloch, Ana E; Tonello, Gabriela; Boyero, Luz

    2017-09-07

    Riparian plant litter is a major energy source for forested streams across the world and its decomposition has repercussions on nutrient cycling, food webs and ecosystem functioning. However, we know little about plant litter dynamics in tropical streams, even though the tropics occupy 40% of the Earth's land surface. Here we investigated spatial and temporal (along a year cycle) patterns of litter inputs and storage in multiple streams of three tropical biomes in Brazil (Atlantic forest, Amazon forest and Cerrado savanna), predicting major differences among biomes in relation to temperature and precipitation regimes. Precipitation explained most of litter inputs and storage, which were generally higher in more humid biomes (litterfall: 384, 422 and 308 g m -2 y -1 , storage: 55, 113 and 38 g m -2 , on average in Atlantic forest, Amazon and Cerrado, respectively). Temporal dynamics varied across biomes in relation to precipitation and temperature, with uniform litter inputs but seasonal storage in Atlantic forest streams, seasonal inputs in Amazon and Cerrado streams, and aseasonal storage in Amazon streams. Our findings suggest that litter dynamics vary greatly within the tropics, but point to the major role of precipitation, which contrasts with the main influence of temperature in temperate areas.

  1. Co-evolution of Riparian Vegetation and Channel Dynamics in an Aggrading Braided River System, Mount Pinatubo, Philippines

    Science.gov (United States)

    Gran, K. B.; Michal, T.

    2014-12-01

    Increased bank stability by riparian vegetation in braided rivers can decrease bed reworking rates and focus the flow. The magnitude of influence and resulting channel morphology are functions of vegetation strength vs. channel dynamics, a concept encapsulated in a dimensionless ratio between timescales for vegetation growth and channel reworking known as T*. We investigate this relationship in an aggrading braided river at Mount Pinatubo, Philippines, and compare results to numerical and physical models. Gradual reductions in post-eruption sediment loads have reduced bed reworking rates, allowing vegetation to persist year-round and impact channel dynamics on the Pasig-Potrero and Sacobia Rivers. From 2009-2011, we collected data detailing vegetation extent, type, density, and root strength. Incorporating these data into RipRoot and BSTEM models shows cohesion due to roots increased from zero in unvegetated conditions to >10.2 kPa in densely-growing grasses. Field-based parameters were incorporated into a cellular model comparing vegetation growth and sediment mobility effects on braided channel dynamics. The model shows that both low sediment mobility and high vegetation strength lead to less active systems, reflecting trends observed in the field. An estimated T* between 0.8 - 2.3 for the Pasig-Potrero River suggests channels were mobile enough to maintain the braidplain width clear of vegetation and even experience slight gains in area through annual removal of existing vegetation. However, persistent vegetation focused flow and thus aggradation over the unvegetated fraction of braidplain, leading to an aggradational imbalance and transition to a more avulsive state. While physical models predict continued narrowing of the active braidplain as T* declines, the future trajectory of channel-vegetation interactions at Pinatubo as sedimentation rates decline appears more complicated due to strong seasonal variability in precipitation and sediment loads. By 2011

  2. Dynamic surface water-groundwater exchange and nitrogen transport in the riparian aquifer of a tidal river

    Science.gov (United States)

    Sawyer, A. H.; Barnes, R.; Wallace, C.; Knights, D.; Tight, D.; Bayer, M.

    2017-12-01

    Tides in coastal rivers can propagate tens to hundreds of kilometers inland and drive large daily changes in water and nitrogen exchange across the sediment-water interface. We use field observations and numerical models to illuminate hydrodynamic controls on nitrogen export from the riparian aquifer to a fresh, tidal reach of White Clay Creek (Delaware, USA). In the banks, an aerobic zone with high groundwater nitrate concentrations occurs near the fluctuating water table. Continuous depth-resolved measurements of redox potential suggest that this zone is relatively stable over tidal timescales but moves up or down in response to storms. The main source of dissolved oxygen is soil air that is imbibed in the zone of water table fluctuations, and the source of nitrate is likely nitrification of ammonium produced locally from the mineralization of organic matter in floodplain soils. Much of the nitrate is removed by denitrification along oscillating flow paths towards the channel. Within centimeters of the sediment-water interface, denitrification is limited by the mixing of groundwater with oxygen-rich river water. Our models predict that the benthic zones of tidal rivers play an important role in removing new nitrate inputs from discharging groundwater but may be less effective at removing nitrate from river water. Nitrate removal and production rates are expected to vary significantly along tidal rivers as permeability, organic matter content, tidal range vary. It is imperative that we understand nitrogen dynamics along tidal rivers and their role in nitrogen export to the coast.

  3. Dynamic of radionuclides behaviour in forest soils

    International Nuclear Information System (INIS)

    Ruehm, W.; Steiner, M.; Wirth, E.; Dvornik, A.; Zhuchenko, T.A.; Kliashtorin, A.; Rafferty, B.; Shaw, G.; Kuchma, N.

    1996-01-01

    Within the research project ECP-5, the dynamics of radionuclides in automorphic forest soils within the 30-km-zone of Chernobyl and of hydromorphic forest soils in Belarus have been investigated. In upland forest soils, the lower layers of the organic horizons are characterized by the highest residence times for radiocesium and represent the largest pool for all radionuclides investigated. According to a preliminary estimate, radiocesium is more mobile compared to 125 Sb, which in turn migrates faster than 60 Co, 144 Ce, and 154 Eu. 106 Ru shows the lowest mobility. With regard to radiocesium, hydromorphic soils exhibit migration rates and transfer factors from soil to trees, which by far exceed those in automorphic soils. Based on a two-component quasi-diffusional model the average bias of 137 Cs in mesotrophic swamp soils was predicted. The activity concentrations of U, Pu, and Cs suggest that U and Pu were originally deposited as hot particles and that U is naturally accumulated in organic horizons

  4. Forest dynamics [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Lee Frelich

    2016-02-01

    Full Text Available Forest dynamics encompass changes in stand structure, species composition, and species interactions with disturbance and environment over a range of spatial and temporal scales. For convenience, spatial scale is defined as individual tree, neighborhood, stand, and landscape. Whether a given canopy-leveling disturbance will initiate a sequence of development in structure with little change in composition or initiate an episode of succession depends on a match or mismatch, respectively, with traits of the dominant tree species that allow the species to survive disturbance. When these match, certain species-disturbance type combinations lock in a pattern of stand and landscape dynamics that can persist for several generations of trees; thus, dominant tree species regulate, as well as respond to, disturbance. A complex interaction among tree species, neighborhood effects, disturbance type and severity, landform, and soils determines how stands of differing composition form and the mosaic of stands that compose the landscape. Neighborhood effects (e.g., serotinous seed rain, sprouting, shading, leaf-litter chemistry, and leaf-litter physical properties operate at small spatial extents of the individual tree and its neighbors but play a central role in forest dynamics by contributing to patch formation at stand scales and dynamics of the entire landscape. Dominance by tree species with neutral to negative neighborhood effects leads to unstable landscape dynamics in disturbance-prone regions, wherein most stands are undergoing succession; stability can only occur under very low-severity disturbance regimes. Dominance by species with positive effects leads to stable landscape dynamics wherein only a small proportion of stands undergo succession at any one time. Positive neighborhood effects are common in temperate and boreal zones, whereas negative effects are more common in tropical climates. Landscapes with positive dynamics have alternate categories

  5. Implementation of a subcanopy solar radiation model on a forested headwater basin in the Southern Appalachians to estimate riparian canopy density and stream insolation for stream temperature models

    Science.gov (United States)

    Belica, L.; Petras, V.; Iiames, J. S., Jr.; Caldwell, P.; Mitasova, H.; Nelson, S. A. C.

    2016-12-01

    Water temperature is a key aspect of water quality and understanding how the thermal regimes of forested headwater streams may change in response to climatic and land cover changes is increasingly important to scientists and resource managers. In recent years, the forested mountain watersheds of the Southeastern U.S. have experienced changing climatic patterns as well as the loss of a keystone riparian tree species and anticipated hydrologic responses include lower summer stream flows and decreased stream shading. Solar radiation is the main source of thermal energy to streams and a key parameter in heat-budget models of stream temperature; a decrease in flow volume combined with a reduction in stream shading during summer have the potential to increase stream temperatures. The high spatial variability of forest canopies and the high spatio-temporal variability in sky conditions make estimating the solar radiation reaching small forested headwater streams difficult. The Subcanopy Solar Radiation Model (SSR) (Bode et al. 2014) is a GIS model that generates high resolution, spatially explicit estimates of solar radiation by incorporating topographic and vegetative shading with a light penetration index derived from leaf-on airborne LIDAR data. To evaluate the potential of the SSR model to provide estimates of stream insolation to parameterize heat-budget models, it was applied to the Coweeta Basin in the Southern Appalachians using airborne LIDAR (NCALM 2009, 1m resolution). The LIDAR derived canopy characteristics were compared to current hyperspectral images of the canopy for changes and the SSR estimates of solar radiation were compared with pyranometer measurements of solar radiation at several subcanopy sites during the summer of 2016. Preliminary results indicate the SSR model was effective in identifying variations in canopy density and light penetration, especially in areas associated with road and stream corridors and tree mortality. Current LIDAR data and

  6. Fire, humans, and climate: modeling distribution dynamics of boreal forest waterbirds.

    Science.gov (United States)

    Börger, Luca; Nudds, Thomas D

    2014-01-01

    Understanding the effects of landscape change and environmental variability on ecological processes is important for evaluating resource management policies, such as the emulation of natural forest disturbances. We analyzed time series of detection/nondetection data using hierarchical models in a Bayesian multi-model inference framework to decompose the dynamics of species distributions into responses to environmental variability, spatial variation in habitat conditions, and population dynamics and interspecific interactions, while correcting for observation errors and variation in sampling regimes. We modeled distribution dynamics of 14 waterbird species (broadly defined, including wetland and riparian species) using data from two different breeding bird surveys collected in the Boreal Shield ecozone within Ontario, Canada. Temporal variation in species occupancy (2000-2006) was primarily driven by climatic variability. Only two species showed evidence of consistent temporal trends in distribution: Ring-necked Duck (Aythya collaris) decreased, and Red-winged Blackbird (Agelaius phoeniceus) increased. The models had good predictive ability on independent data over time (1997-1999). Spatial variation in species occupancy was strongly related to the distribution of specific land cover types and habitat disturbance: Fire and forest harvesting influenced occupancy more than did roads, settlements, or mines. Bioclimatic and habitat heterogeneity indices and geographic coordinates exerted negligible influence on most species distributions. Estimated habitat suitability indices had good predictive ability on spatially independent data (Hudson Bay Lowlands ecozone). Additionally, we detected effects of interspecific interactions. Species responses to fire and forest harvesting were similar for 13 of 14 species; thus, forest-harvesting practices in Ontario generally appeared to emulate the effects of fire for waterbirds over timescales of 10-20 years. Extrapolating to all

  7. Scaling of Sediment Dynamics in a Reach-Scale Laboratory Model of a Sand-Bed Stream with Riparian Vegetation

    Science.gov (United States)

    Gorrick, S.; Rodriguez, J. F.

    2011-12-01

    A movable bed physical model was designed in a laboratory flume to simulate both bed and suspended load transport in a mildly sinuous sand-bed stream. Model simulations investigated the impact of different vegetation arrangements along the outer bank to evaluate rehabilitation options. Preserving similitude in the 1:16 laboratory model was very important. In this presentation the scaling approach, as well as the successes and challenges of the strategy are outlined. Firstly a near-bankfull flow event was chosen for laboratory simulation. In nature, bankfull events at the field site deposit new in-channel features but cause only small amounts of bank erosion. Thus the fixed banks in the model were not a drastic simplification. Next, and as in other studies, the flow velocity and turbulence measurements were collected in separate fixed bed experiments. The scaling of flow in these experiments was simply maintained by matching the Froude number and roughness levels. The subsequent movable bed experiments were then conducted under similar hydrodynamic conditions. In nature, the sand-bed stream is fairly typical; in high flows most sediment transport occurs in suspension and migrating dunes cover the bed. To achieve similar dynamics in the model equivalent values of the dimensionless bed shear stress and the particle Reynolds number were important. Close values of the two dimensionless numbers were achieved with lightweight sediments (R=0.3) including coal and apricot pips with a particle size distribution similar to that of the field site. Overall the moveable bed experiments were able to replicate the dominant sediment dynamics present in the stream during a bankfull flow and yielded relevant information for the analysis of the effects of riparian vegetation. There was a potential conflict in the strategy, in that grain roughness was exaggerated with respect to nature. The advantage of this strategy is that although grain roughness is exaggerated, the similarity of

  8. Forest production dynamics along a wood density spectrum in eastern US forests

    Science.gov (United States)

    C.W. Woodall; M.B. Russell; B.F. Walters; A.W. D' Amato; K. Zhu; S.S. Saatchi

    2015-01-01

    Emerging plant economics spectrum theories were confirmed across temperate forest systems of the eastern US where the use of a forest stand's mean wood density elucidated forest volume and biomass production dynamics integrating aspects of climate, tree mortality/growth, and rates of site occupancy.

  9. Rocky Mountain Riparian Digest

    Science.gov (United States)

    Deborah M. Finch

    2008-01-01

    The Rocky Mountain Riparian Digest presents the many facets of riparian research at the station. Included are articles about protecting the riparian habitat, the social and economic values of riparian environments, watershed restoration, remote sensing tools, and getting kids interested in the science.

  10. Clustering Timber Harvests and the Effects of Dynamic Forest Management Policy on Forest Fragmentation

    Science.gov (United States)

    Eric J. Gustafson

    1998-01-01

    To integrate multiple uses (mature forest and commodity production) better on forested lands, timber management strategies that cluster harvests have been proposed. One such approach clusters harvest activity in space and time, and rotates timber production zones across the landscape with a long temporal period (dynamic zoning). Dynamic zoning has...

  11. Assessment of Vegetation Density and Soil Macrofauna Relationship in Riparian Forest of Karkhe River for the Determination of Rivers Buffer Zone

    Directory of Open Access Journals (Sweden)

    SH. Gholami

    2014-06-01

    Full Text Available The spatial distribution of soil organisms is influenced by the plant cover, thus resulting in a horizontal mosaic of areas subjected to gradients of nutrient availability and microclimatic conditions.This study was conducted to investigate the spatial variability of soil macrofauna in relation to vegetation density in the riparian forest landscape of Karkhe. The vegetation density was determined by calculating the NDVI index. Soil macrofauna were sampled using 200 sampling points along parallel transects (perpendicular to the river. The maximum distance between samples was 0.5 km. Soil macrofauna were extracted from 50 cm×50 cm×25 cm soil monolith by the hand-sorting procedure. Abundance, diversity (Shannon H’ index, richness (Menhinick index and evenness (Sheldon index were calculated. Soil macrofauna and NDVI data were analyzed using geostatistics (variogram in order to describe and quantify the spatial continuity. The variograms were spherical, revealing the presence of spatial autocorrelation. The range of influence was 1724 m for abundance, 1326 m for diversity, 1825 m for richness, 1450 for evenness and 1977 m for NDVI. The kriging maps showed that the NDVI Index and soil macrofauna had spatial variability. The spatial pattern of soil macrofauna abundance and biodiversity were similar to the spatial pattern of vegetation density as shown in the correlation.

  12. Human uses of forested watersheds and riparian corridors: hazard mitigation as an ecosystem service, with examples from Panama, Puerto Rico, and Venezuela

    Science.gov (United States)

    Larsen, M. C.

    2015-12-01

    Humans have long favored settlement along rivers for access to water supply for drinking and agriculture, for transport corridors, and for food sources. Additionally, settlement in or near montane forests include benefits such as food sources, wood supply, esthetic values, and high quality water resources derived from watersheds where upstream human disturbance and environmental degradation is generally reduced. However, the advantages afforded by these riparian and montane settings pose episodic risks for communities located there as floods, landslides, and wildfires cause loss of life, destroy infrastructure, and damage or destroy crops. A basic understanding of flood probability and magnitude as well as hillslope stability by residents in these environments can mitigate these risks. Early humans presumably developed some degree of knowledge about these risks by means of their long periods of occupation in these environments and their observations of seasonal and storm rainfall patterns and river discharge, which became more refined as agriculture developed over the past 10,000 years. Modern global urbanization, particularly in regions of rapid economic growth, has resulted in much of this "organic" knowledge being lost, as rural populations move into megacities, many of which encroach on floodplains and mountain fronts. Moreover, the most likely occupants of these hazardous locations are often economically constrained, increasing their vulnerabity. Effective stewardship of river floodplains and upstream montane forests yields a key ecosystem service, which in addition to the well-known services, ie. water, hydroelectric energy, etc., provides a risk mitigation service, by reducing hazard and vulnerability. Puerto Rico, Panama, and Venezuela illustrate a range of practices and results, providing useful examples for planners and land use managers.

  13. Forest Dynamics in the Eastern Ghats of Tamil Nadu, India

    Science.gov (United States)

    Jayakumar, S.; Ramachandran, A.; Bhaskaran, G.; Heo, J.

    2009-02-01

    The primary deciduous forests in the Eastern Ghats (EG) of Tamil Nadu (TN) India have undergone many changes owing to various need-based forest managements, such as timber extraction for industry, railway sleepers, charcoal, and forest clearance for hydroelectric projects and agriculture, during preindependence and postindependence periods (i.e., from 1800 to 1980). The enactment of a forest conservation act during the 1980s changed the perception of forest managers from utilization to conservation. This study was taken up to assess the forests dynamics in the EG of TN spatially between 1990 and 2003 and nonspatially between 1900 and the 1980s. Landsat Thematic Mapper (TM) and Indian Remote Sensing satellite (IRS) 1D Linear Imaging and Self Scanning (LISS III) data were used to assess forests during 1990 and 2003, respectively. Field floristic survey and secondary data (such as published literature, floras, books, and forest working plans) were used to assess the forest dynamics in terms of forest type and species composition among the preindependence period, the postindependence period, and the present (i.e., before and after 1980). The satellite data analysis revealed a considerable amount of changes in all forest types during the 13 years. The comparison of species composition and forest types between the past and present revealed that need-based forest management along with anthropogenic activity have altered the primary deciduous forest in to secondary and postextraction secondary forests such as southern thorn and southern thorn scrub forests in the middle [400-900 m above mean sea level (MSL)] and lower slopes (900 m MSL) and plateau seemed not to be much affected by the forest management. The changes estimated by the satellite data processing in the major forest types such as evergreen, deciduous, southern thorn, and southern thorn scrub are really alarming because these changes have occurred after the implementation of a forest conservation act. The

  14. Survival and growth of restored Piedmont riparian forests as affected by site preparation, planting stock, and planting aids

    Science.gov (United States)

    Chelsea M. Curtis; W. Michael Aust; John R. Seiler; Brian D. Strahm

    2015-01-01

    Forest mitigation sites may have poor survival and growth of planted trees due to poor drainage, compacted soils, and lack of microtopography. The effects of five replications of five forestry mechanical site preparation techniques (Flat, Rip, Bed, Pit, and Mound), four regeneration sources (Direct seed, Bare root, Tubelings, and Gallon), and three planting aids (None...

  15. SELECTIVE FORAGING ON WOODY SPECIES BY THE BEAVER CASTOR FIBER, AND ITS IMPACT ON A RIPARIAN WILLOW FOREST

    NARCIS (Netherlands)

    NOLET, BA; HOEKSTRA, A; OTTENHEIM, MM

    1994-01-01

    Beavers were re-introduced in the Biesbosch, The Netherlands, a wood dominated by willows Salix spp. Conservationists expected that herbivory by beavers would enhance succession to a mixed broad-leaved forest. Willows formed the staple food of the beavers, but they removed only 1.4% of the standing

  16. Are riparian forest reserves sources of invertebrate biodiversity spillover and associated ecosystem functions in oil palm landscapes?

    Czech Academy of Sciences Publication Activity Database

    Gray, C. L.; Simmons, B. I.; Fayle, Tom Maurice; Mann, D. J.; Slade, E. M.

    2016-01-01

    Roč. 194, Feb 01 (2016), s. 176-183 ISSN 0006-3207 R&D Projects: GA ČR GA14-32302S; GA ČR(CZ) GA16-09427S Institutional support: RVO:60077344 Keywords : ecosystem function * forest fragments * tropical agriculture Subject RIV: EH - Ecology, Behaviour Impact factor: 4.022, year: 2016 http://www.sciencedirect.com/science/article/pii/S0006320715301956

  17. Variable effects of climate on forest growth in relation to climate extremes, disturbance, and forest dynamics.

    Science.gov (United States)

    Itter, Malcolm S; Finley, Andrew O; D'Amato, Anthony W; Foster, Jane R; Bradford, John B

    2017-06-01

    Changes in the frequency, duration, and severity of climate extremes are forecast to occur under global climate change. The impacts of climate extremes on forest productivity and health remain difficult to predict due to potential interactions with disturbance events and forest dynamics-changes in forest stand composition, density, size and age structure over time. Such interactions may lead to non-linear forest growth responses to climate involving thresholds and lag effects. Understanding how forest dynamics influence growth responses to climate is particularly important given stand structure and composition can be modified through management to increase forest resistance and resilience to climate change. To inform such adaptive management, we develop a hierarchical Bayesian state space model in which climate effects on tree growth are allowed to vary over time and in relation to past climate extremes, disturbance events, and forest dynamics. The model is an important step toward integrating disturbance and forest dynamics into predictions of forest growth responses to climate extremes. We apply the model to a dendrochronology data set from forest stands of varying composition, structure, and development stage in northeastern Minnesota that have experienced extreme climate years and forest tent caterpillar defoliation events. Mean forest growth was most sensitive to water balance variables representing climatic water deficit. Forest growth responses to water deficit were partitioned into responses driven by climatic threshold exceedances and interactions with insect defoliation. Forest growth was both resistant and resilient to climate extremes with the majority of forest growth responses occurring after multiple climatic threshold exceedances across seasons and years. Interactions between climate and disturbance were observed in a subset of years with insect defoliation increasing forest growth sensitivity to water availability. Forest growth was particularly

  18. African savanna-forest boundary dynamics

    DEFF Research Database (Denmark)

    Cuni Sanchez, Aida; White, Lee J. T.; Calders, Kim

    2016-01-01

    -term inventory plots we quantify changes in vegetation structure, above-ground biomass (AGB) and biodiversity of trees ≥10 cm diameter over 20 years for five vegetation types: savanna; colonising forest (F1), monodominant Okoume forest (F2); young Marantaceae forest (F3); and mixed Marantaceae forest (F4...... substantially in structure, AGB or diversity. Critically, the stability of the F3 stage implies that this stage may be maintained for long periods. Soil carbon was low, and did not show a successional gradient as for AGB and diversity. TLS vertical plant profiles showed distinctive differences amongst...... the vegetation types, indicating that this technique can improve ecological understanding. We highlight two points: (i) as forest colonises, changes in biodiversity are much slower than changes in forest structure or AGB; and (ii) all forest types store substantial quantities of carbon. Multidecadal monitoring...

  19. Dynamics of Plains Cottonwood ( Populus deltoides) Forests and Historical Landscape Change along Unchannelized Segments of the Missouri River, USA

    Science.gov (United States)

    Dixon, Mark D.; Johnson, W. Carter; Scott, Michael L.; Bowen, Daniel E.; Rabbe, Lisa A.

    2012-05-01

    Construction of six large dams and reservoirs on the Missouri River over the last 50-75 years has resulted in major landscape changes and alterations in flow patterns, with implications for riparian forests dominated by plains cottonwood ( Populus deltoides). We quantified changes in land cover from 1892-1950s and the 1950s-2006 and the current extent and age structure of cottonwood forests on seven segments (two reservoir and five remnant floodplain) comprising 1127 km (53 %) of the unchannelized upper two-thirds of the Missouri River. Riparian forest area declined by 49 %; grassland 61 %; shrubland 52 %; and sandbar habitat 96 %; while agricultural cropland increased six-fold and river/reservoir surface area doubled from 1892 to 2006. Net rates of erosion and accretion declined between the 1892-1950s and 1950s-2006 periods. Accretion exceeded erosion on remnant floodplain segments, resulting in declines in active channel width, particularly in 1950s-2006. Across all study segments in 2006, most cottonwood stands (67 %) were >50 years old, 22 % were 25-50 years old, and only 10 % were <25 years old. Among stands <50 years old, the higher proportion of 25-50 year old stands represents recruitment that accompanied initial post-dam channel narrowing; while declines in sandbar and shrubland area and the low proportion of stands <25 years old suggest declines in geomorphic dynamism and limited recruitment under recent river management. Future conservation and restoration efforts should focus both on limiting further loss of remnant cottonwood stands and developing approaches to restore river dynamics and cottonwood recruitment processes.

  20. A framework for analyzing workforce dynamics in forest harvesting in ...

    African Journals Online (AJOL)

    A framework for measuring, monitoring and managing labour dynamics is used and tested in forest harvesting operations in South Africa and the results presented. Overall, the workforce in forest harvesting is unstable: the median labour turnover (monthly basis) and absenteeism (daily basis) are 4 % and 6 %, respectively.

  1. Modelling forest dynamics along climate gradients in Bolivia

    NARCIS (Netherlands)

    Seiler, C.; Hutjes, R.W.A.; Kruijt, B.; Quispe, J.; Añez, S.; Arora, V.K.; Melton, J.R.; Hickler, T.; Kabat, P.

    2014-01-01

    Dynamic vegetation models have been used to assess the resilience of tropical forests to climate change, but the global application of these modeling experiments often misrepresents carbon dynamics at a regional level, limiting the validity of future projections. Here a dynamic vegetation model

  2. Variable effects of climate on forest growth in relation to climate extremes, disturbance, and forest dynamics

    Science.gov (United States)

    Itter, Malcolm S.; Finley, Andrew O.; D'Amato, Anthony W.; Foster, Jane R.; Bradford, John B.

    2017-01-01

    Changes in the frequency, duration, and severity of climate extremes are forecast to occur under global climate change. The impacts of climate extremes on forest productivity and health remain difficult to predict due to potential interactions with disturbance events and forest dynamics—changes in forest stand composition, density, size and age structure over time. Such interactions may lead to non-linear forest growth responses to climate involving thresholds and lag effects. Understanding how forest dynamics influence growth responses to climate is particularly important given stand structure and composition can be modified through management to increase forest resistance and resilience to climate change. To inform such adaptive management, we develop a hierarchical Bayesian state space model in which climate effects on tree growth are allowed to vary over time and in relation to past climate extremes, disturbance events, and forest dynamics. The model is an important step toward integrating disturbance and forest dynamics into predictions of forest growth responses to climate extremes. We apply the model to a dendrochronology data set from forest stands of varying composition, structure, and development stage in northeastern Minnesota that have experienced extreme climate years and forest tent caterpillar defoliation events. Mean forest growth was most sensitive to water balance variables representing climatic water deficit. Forest growth responses to water deficit were partitioned into responses driven by climatic threshold exceedances and interactions with insect defoliation. Forest growth was both resistant and resilient to climate extremes with the majority of forest growth responses occurring after multiple climatic threshold exceedances across seasons and years. Interactions between climate and disturbance were observed in a subset of years with insect defoliation increasing forest growth sensitivity to water availability. Forest growth was particularly

  3. The Importance and Future Condition of Western Riparian Ecosystems as Migratory Bird Habitat

    Science.gov (United States)

    Susan K. Skagen; Rob Hazlewood; Michael L. Scott

    2005-01-01

    Riparian forests have long been considered important habitats for breeding western landbirds, and growing evidence reinforces their importance during the migratory period as well. Extensive modification of natural flow regimes, grazing, and forest clearing along many rivers in the western U.S. have led to loss and simplification of native riparian forests and to...

  4. Flooding Regime Impacts on Radiation, Evapotranspiration, and Latent Energy Fluxes over Groundwater-Dependent Riparian Cottonwood and Saltcedar Forests

    Directory of Open Access Journals (Sweden)

    James Cleverly

    2015-01-01

    Full Text Available Radiation and energy balances are key drivers of ecosystem water and carbon cycling. This study reports on ten years of eddy covariance measurements over groundwater-dependent ecosystems (GDEs in New Mexico, USA, to compare the role of drought and flooding on radiation, water, and energy budgets of forests differing in species composition (native cottonwood versus nonnative saltcedar and flooding regime. After net radiation (700–800 W m−2, latent heat flux was the largest energy flux, with annual values of evapotranspiration exceeding annual precipitation by 250–600%. Evaporative cooling dominated the energy fluxes of both forest types, although cottonwood generated much lower daily values of sensible heat flux (<−5 MJ m−2 d−1. Drought caused a reduction in evaporative cooling, especially in the saltcedar sites where evapotranspiration was also reduced, but without a substantial decline in depth-to-groundwater. Our findings have broad implications on water security and the management of native and nonnative vegetation within semiarid southwestern North America. Specifically, consideration of the energy budgets of GDEs as they respond to fluctuations in climatic conditions can inform the management options for reducing evapotranspiration and maintaining in-stream flow, which is legally mandated as part of interstate and international water resources agreements.

  5. Riparian adaptive management symposium: a conversation between scientists and management

    Science.gov (United States)

    Douglas F. Ryan; John M. Calhoun

    2010-01-01

    Scientists, land managers and policy makers discussed whether riparian (stream side) forest management and policy for state, federal and private lands in western Washington are consistent with current science. Answers were mixed: some aspects of riparian policy and management have a strong basis in current science, while other aspects may not. Participants agreed that...

  6. Influences of watershed geomorphology on extent and composition of riparian vegetation

    Science.gov (United States)

    Blake M. Engelhardt; Peter J. Weisberg; Jeanne C. Chambers

    2011-01-01

    Watershed (drainage basin) morphometry and geology were derived from digital data sets (DEMs and geologic maps). Riparian corridors were classified into five vegetation types (riparian forest, riparian shrub, wet/mesic meadow, dry meadow and shrub dry meadow) using high-resolution aerial photography. Regression and multivariate analyses were used to relate geomorphic...

  7. From soil water to surface water – how the riparian zone controls element transport from a boreal forest to a stream

    Directory of Open Access Journals (Sweden)

    F. Lidman

    2017-06-01

    Full Text Available Boreal headwaters are often lined by strips of highly organic soils, which are the last terrestrial environment to leave an imprint on discharging groundwater before it enters a stream. Because these riparian soils are so different from the Podzol soils that dominate much of the boreal landscape, they are known to have a major impact on the biogeochemistry of important elements such as C, N, P and Fe and the transfer of these elements from terrestrial to aquatic ecosystems. For most elements, however, the role of the riparian zone has remained unclear, although it should be expected that the mobility of many elements is affected by changes in, for example, pH, redox potential and concentration of organic carbon as they are transported through the riparian zone. Therefore, soil water and groundwater was sampled at different depths along a 22 m hillslope transect in the Krycklan catchment in northern Sweden using soil lysimeters and analysed for a large number of major and trace elements (Al, As, B, Ba, Ca, Cd, Cl, Co, Cr, Cs, Cu, Fe, K, La, Li, Mg, Mn, Na, Ni, Pb, Rb, Se, Si, Sr, Th, Ti, U, V, Zn, Zr and other parameters such as sulfate and total organic carbon (TOC. The results showed that the concentrations of most investigated elements increased substantially (up to 60 times as the water flowed from the uphill mineral soils and into the riparian zone, largely as a result of higher TOC concentrations. The stream water concentrations of these elements were typically somewhat lower than in the riparian zone, but still considerably higher than in the uphill mineral soils, which suggests that riparian soils have a decisive impact on the water quality of boreal streams. The degree of enrichment in the riparian zone for different elements could be linked to the affinity for organic matter, indicating that the pattern with strongly elevated concentrations in riparian soils is typical for organophilic substances. One likely explanation is that the

  8. Floristic and phytosociological description of a riparian forest and the relationship with the edaphic environment in Caiuá Ecological Station - Paraná - Brazil

    Directory of Open Access Journals (Sweden)

    Lysias Vellozo da Costa Filho

    2006-09-01

    Full Text Available Relationship in soil physical and chemical properties of soil, floristic and phytosociological association of semi-deciduous riparian forest of the Paranapanema River (R and Rosana Reservoir (Re in the Caiuá Ecological Station were evaluated. Aerial photography and satellite image were used to determine the forest cover and to locate 15 transects 50 x 30m (1500m²,which were used to sample trees with diameters at breast height (DBH>15 cm. R contained 1487 individuals from 33 families, 64 genders and 73 species. The Shannon-weaver index (H' was 3.318. Re contained 1146 individuals from 35 families, 72 genders and 85 species and the H' was 3.755. There was a statistically significant difference (PDas análises das propriedades física e química dos solos, da florística e da fítossociológica da vegetação arbórea de fragmentos da floresta estacional semidecidual localizados às margens do Rio Paranapanema (R e do Reservatório de Rosana (Re na Estação Ecológica do Caiuá (22°41'S e 52°55'W, verificou-se as correlações vegetação x solo. Utilizou-se fotografias aéreas e imagens de satélite para determinar a similaridade da cobertura florestal e alocar 15 transectos de 50m x 30m (1500m² cada, amostrou-se os indivíduos com perímetro a altura do peito (PAP 15 cm. No R amostrou-se 1487 indivíduos, de 33 famílias, 64 gêneros e 73 espécies e índice de Shannon-weaver (H' de 3,318. No Re registrou-se 1146 indivíduos de 35 famílias, 72 gêneros e 85 espécies e H' de 3,755. Os resultados mostraram ambientes estatisticamente diferentes e efetiva correlação entre os atributos físicos do solo e os Valores de Importância (VI ordenados pela Detrended Correspondence Analysis (DCA.

  9. Forest Ecosystem Dynamics Assessment and Predictive Modelling in Eastern Himalaya

    Science.gov (United States)

    Kushwaha, S. P. S.; Nandy, S.; Ahmad, M.; Agarwal, R.

    2011-09-01

    This study focused on the forest ecosystem dynamics assessment and predictive modelling deforestation and forest cover prediction in a part of north-eastern India i.e. forest areas along West Bengal, Bhutan, Arunachal Pradesh and Assam border in Eastern Himalaya using temporal satellite imagery of 1975, 1990 and 2009 and predicted forest cover for the period 2028 using Cellular Automata Markov Modedel (CAMM). The exercise highlighted large-scale deforestation in the study area during 1975-1990 as well as 1990-2009 forest cover vectors. A net loss of 2,334.28 km2 forest cover was noticed between 1975 and 2009, and with current rate of deforestation, a forest area of 4,563.34 km2 will be lost by 2028. The annual rate of deforestation worked out to be 0.35 and 0.78% during 1975-1990 and 1990-2009 respectively. Bamboo forest increased by 24.98% between 1975 and 2009 due to opening up of the forests. Forests in Kokrajhar, Barpeta, Darrang, Sonitpur, and Dhemaji districts in Assam were noticed to be worst-affected while Lower Subansiri, West and East Siang, Dibang Valley, Lohit and Changlang in Arunachal Pradesh were severely affected. Among different forest types, the maximum loss was seen in case of sal forest (37.97%) between 1975 and 2009 and is expected to deplete further to 60.39% by 2028. The tropical moist deciduous forest was the next category, which decreased from 5,208.11 km2 to 3,447.28 (33.81%) during same period with further chances of depletion to 2,288.81 km2 (56.05%) by 2028. It noted progressive loss of forests in the study area between 1975 and 2009 through 1990 and predicted that, unless checked, the area is in for further depletion of the invaluable climax forests in the region, especially sal and moist deciduous forests. The exercise demonstrated high potential of remote sensing and geographic information system for forest ecosystem dynamics assessment and the efficacy of CAMM to predict the forest cover change.

  10. FOREST ECOSYSTEM DYNAMICS ASSESSMENT AND PREDICTIVE MODELLING IN EASTERN HIMALAYA

    Directory of Open Access Journals (Sweden)

    S. P. S. Kushwaha

    2012-09-01

    Full Text Available This study focused on the forest ecosystem dynamics assessment and predictive modelling deforestation and forest cover prediction in a part of north-eastern India i.e. forest areas along West Bengal, Bhutan, Arunachal Pradesh and Assam border in Eastern Himalaya using temporal satellite imagery of 1975, 1990 and 2009 and predicted forest cover for the period 2028 using Cellular Automata Markov Modedel (CAMM. The exercise highlighted large-scale deforestation in the study area during 1975–1990 as well as 1990–2009 forest cover vectors. A net loss of 2,334.28 km2 forest cover was noticed between 1975 and 2009, and with current rate of deforestation, a forest area of 4,563.34 km2 will be lost by 2028. The annual rate of deforestation worked out to be 0.35 and 0.78% during 1975–1990 and 1990–2009 respectively. Bamboo forest increased by 24.98% between 1975 and 2009 due to opening up of the forests. Forests in Kokrajhar, Barpeta, Darrang, Sonitpur, and Dhemaji districts in Assam were noticed to be worst-affected while Lower Subansiri, West and East Siang, Dibang Valley, Lohit and Changlang in Arunachal Pradesh were severely affected. Among different forest types, the maximum loss was seen in case of sal forest (37.97% between 1975 and 2009 and is expected to deplete further to 60.39% by 2028. The tropical moist deciduous forest was the next category, which decreased from 5,208.11 km2 to 3,447.28 (33.81% during same period with further chances of depletion to 2,288.81 km2 (56.05% by 2028. It noted progressive loss of forests in the study area between 1975 and 2009 through 1990 and predicted that, unless checked, the area is in for further depletion of the invaluable climax forests in the region, especially sal and moist deciduous forests. The exercise demonstrated high potential of remote sensing and geographic information system for forest ecosystem dynamics assessment and the efficacy of CAMM to predict the forest cover change.

  11. Biomass dynamics in a logged forest

    NARCIS (Netherlands)

    Nam, Vu Thanh; Anten, Niels P.R.; Kuijk, van Marijke

    2018-01-01

    Wood density (WD) is believed to be a key trait in driving growth strategies of tropical forest species, and as it entails the amount of mass per volume of wood, it also tends to correlate with forest carbon stocks. Yet there is relatively little information on how interspecific variation in WD

  12. The dynamics of strangling among forest trees.

    Science.gov (United States)

    Okamoto, Kenichi W

    2015-11-07

    Strangler trees germinate and grow on other trees, eventually enveloping and potentially even girdling their hosts. This allows them to mitigate fitness costs otherwise incurred by germinating and competing with other trees on the forest floor, as well as minimize risks associated with host tree-fall. If stranglers can themselves host other strangler trees, they may not even seem to need non-stranglers to persist. Yet despite their high fitness potential, strangler trees neither dominate the communities in which they occur nor is the strategy particularly common outside of figs (genus Ficus). Here we analyze how dynamic interactions between strangling and non-strangling trees can shape the adaptive landscape for strangling mutants and mutant trees that have lost the ability to strangle. We find a threshold which strangler germination rates must exceed for selection to favor the evolution of strangling, regardless of how effectively hemiepiphytic stranglers may subsequently replace their hosts. This condition describes the magnitude of the phenotypic displacement in the ability to germinate on other trees necessary for invasion by a mutant tree that could potentially strangle its host following establishment as an epiphyte. We show how the relative abilities of strangling and non-strangling trees to occupy empty sites can govern whether strangling is an evolutionarily stable strategy, and obtain the conditions for strangler coexistence with non-stranglers. We then elucidate when the evolution of strangling can disrupt stable coexistence between commensal epiphytic ancestors and their non-strangling host trees. This allows us to highlight parallels between the invasion fitness of strangler trees arising from commensalist ancestors, and cases where strangling can arise in concert with the evolution of hemiepiphytism among free-standing ancestors. Finally, we discuss how our results can inform the evolutionary ecology of antagonistic interactions more generally

  13. Evaluation of the riparian forest state program in Pitangueiras county, Parana / Avaliação do programa estadual “Mata Ciliar” no município de Pitangueiras, Paraná

    Directory of Open Access Journals (Sweden)

    Cristovon Videira Ripol

    2009-10-01

    Full Text Available Riparian forest restoration is fundamental for maintenance of vegetable, animal and human life. The objective of this study was to evaluate the efficiency of a Riparian Forest state program in the enlargement of the riparian forests in Pitangueiras county, state of Paraná, in the period of 2004 to 2006. Concerning the riparian reforestation, it was ansewered the reasons that convinced the farmers to join the program, the main difficulties found in its execution, and their views on environmental preservation and law. The results by means of interviews with the farmers and county leaders. It was concluded that the reparian forest state program was efficient due to the partner ship between Pitangueiras City Hall, Government Department of Environment and Coffee Farmer Association. The installation of a native tree nursery in Pitangueiras offered plants to farmers at the opportune period for planting; the farmers have conscience about the necessity of planting riparing forests; and is necessary to do a public policy to include the farmers in the carbon credict projects created with the riparian forest restoration.O uso de extratos vegetais com propriedades nematicidas no controle de fitonematóides representa mais uma alternativa para os pequenos produtores, com valor prático e econômico, e sem riscos de contaminação do ambiente. A adição ao solo dos extratos aquosos de 20 espécies de plantas foi avaliada sobre a população de Meloidogyne javanica em plantas de tomateiro, em casa de vegetação. Estas foram divididas em dois grupos e avaliadas em dois experimentos separados. No mesmo dia em que se infestou o solo com 5.000 ovos do nematóide, adicionou-se 20 mL dos extratos aquosos obtidos de folhas de artemísia (Chrysanthemum parthenium, bardana (Arctium lappa, capim cidreira (Cymbopogon citratus, carqueja (Bacharis trimera, cavalinha (Equisetum sp., cinamomo (Melia azedarach, hortelã (Mentha sp., mamona (Ricinus communis, manjeric

  14. Distribution and dynamics of mangrove forests of South Asia

    Science.gov (United States)

    Giri, Chandra; Long, Jordan; Abbas, Sawaid; Murali, R. Mani; Qamer, Faisal M.; Pengra, Bruce; Thau, David

    2014-01-01

    Mangrove forests in South Asia occur along the tidal sea edge of Bangladesh, India, Pakistan, and Sri Lanka. These forests provide important ecosystem goods and services to the region's dense coastal populations and support important functions of the biosphere. Mangroves are under threat from both natural and anthropogenic stressors; however the current status and dynamics of the region's mangroves are poorly understood. We mapped the current extent of mangrove forests in South Asia and identified mangrove forest cover change (gain and loss) from 2000 to 2012 using Landsat satellite data. We also conducted three case studies in Indus Delta (Pakistan), Goa (India), and Sundarbans (Bangladesh and India) to identify rates, patterns, and causes of change in greater spatial and thematic details compared to regional assessment of mangrove forests.

  15. Effects of riparian buffers on hydrology of northern seasonal ponds

    Science.gov (United States)

    Randall K. Kolka; Brian J. Palik; Daniel P. Tersteeg; James C. Bell

    2011-01-01

    Although seasonal ponds are common in northern, glaciated, forested landscapes, forest management guidelines are generally lacking for these systems. The objective of this study was to determine the effect of riparian buffer type on seasonal pond hydrology following harvest of the adjacent upland forest. A replicated block design consisting of four buffer treatments...

  16. Best management practices for riparian areas

    Science.gov (United States)

    Michael J. Phillips; Lloyd W. Swift; Charles R. Blinn

    2000-01-01

    Forest streams, lakes, and other water bodies create unique conditions along their margins that control and influence transfers of energy, nutrients, and sediments between aquatic and terrestrial systems. These riparian areas are among the most critical features of the landscape because they contain a rich diversity of plants and animals and help to maintain water...

  17. RELATIONSHIPS AMONG GEOMORPHOLOGY, HYDROLOGY, AND VEGETATION IN RIPARIAN MEADOWS: RESTORATION IMPLICATIONS

    Science.gov (United States)

    Vegetation patterns and dynamics within riparian corridors are controlled largely by geomorphic position, substrate characteristics and hydrologic regimes. Understanding management and restoration options for riparian meadow complexes exhibiting stream incision requires knowledge...

  18. Dynamics of radionuclides in forest environments

    International Nuclear Information System (INIS)

    Belli, M.; Tikhomirov, F.A.; Kliashtorin, A.; Shcheglov, A.; Rafferty, B.; Shaw, G.; Wirth, E.; Kammerer, L.; Ruehm, W.; Steiner, M.; Delvaux, B.; Maes, E.; Kruyts, N.; Bunzl, K.; Dvornik, A.M.; Kuchma, N.

    1996-01-01

    In the CIS countries, during the Chernobyl accident, more than 30000 km 2 of forested areas received a 137 Cs deposition higher than 37 kBq m -2 and about 1000 km 2 a deposition of radiocesium higher than 1.5 MBq m -2 . Before the accident only few data were available on the behaviour of radionuclides in forests and during last eight years, the understanding of the fate of radionuclides in these ecosystems has been improved significantly. This paper reports the results achieved in the frame of 1991-1996 EU/CIS collaborative project on the consequences of the Chernobyl accident. The ECP-5 project deals with the impact of radioactive contamination on natural and semi-natural environment. The investigations were carried out in different forest ecosystems, located in the near field (within the 30-km zone around the Chernobyl nuclear power plant) as well as in the far field in the CIS and in the western Europe countries. The results achieved have been used to develop a simplified model representation of the behaviour of radiocesium within forest ecosystems

  19. Mathematical model of 137Cs dynamics in the deciduous forest

    International Nuclear Information System (INIS)

    Mamikhin, S.V.; Klyashtorin, A.L.

    1999-01-01

    A mathematical model of 137 Cs behaviour in the forest ecosystem is presented. The behaviour of this radionuclide is assumed to obey the same regularities as the behaviour of its stable chemical analogue, potassium. Radionuclide dynamics are considered in parallel with the dynamics of the phytomass. Radionuclides contained in the vegetation are pooled into two basic compartments: external and internal contamination, with separate analysis of each. The model was verified using the data obtained in the 30-km zone of the Chernobyl NPP in 1986-1994. The algorithm described was found to be the most efficient in terms of 137 Cs behaviour in the forest environments

  20. Forest composition modifies litter dynamics and decomposition in regenerating tropical dry forest.

    Science.gov (United States)

    Schilling, Erik M; Waring, Bonnie G; Schilling, Jonathan S; Powers, Jennifer S

    2016-09-01

    We investigated how forest composition, litter quality, and rainfall interact to affect leaf litter decomposition across three successional tropical dry forests in Costa Rica. We monitored litter stocks and bulk litter turnover in 18 plots that exhibit substantial variation in soil characteristics, tree community structure, fungal communities (including forests dominated by ecto- or arbuscular mycorrhizal host trees), and forest age. Simultaneously, we decomposed three standard litter substrates over a 6-month period spanning an unusually intense drought. Decay rates of standard substrates depended on the interaction between litter identity and forest type. Decomposition rates were correlated with tree and soil fungal community composition as well as soil fertility, but these relationships differed among litter types. In low fertility soils dominated by ectomycorrhizal oak trees, bulk litter turnover rates were low, regardless of soil moisture. By contrast, in higher fertility soils that supported mostly arbuscular mycorrhizal trees, bulk litter decay rates were strongly dependent on seasonal water availability. Both measures of decomposition increased with forest age, as did the frequency of termite-mediated wood decay. Taken together, our results demonstrate that soils and forest age exert strong control over decomposition dynamics in these tropical dry forests, either directly through effects on microclimate and nutrients, or indirectly by affecting tree and microbial community composition and traits, such as litter quality.

  1. Forest microbiome: diversity, complexity and dynamics

    Czech Academy of Sciences Publication Activity Database

    Baldrian, Petr

    2017-01-01

    Roč. 41, č. 2 (2017), s. 109-130 ISSN 0168-6445 R&D Projects: GA ČR GA13-06763S; GA ČR GA13-27454S; GA MŠk(CZ) LD15086 Institutional support: RVO:61388971 Keywords : forests * microbiome * habitat Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 12.198, year: 2016

  2. Temporal carbon dynamics of forests in Washington, US: implications for ecological theory and carbon management

    Science.gov (United States)

    Crystal L. Raymond; Donald. McKenzie

    2014-01-01

    We quantified carbon (C) dynamics of forests in Washington, US using theoretical models of C dynamics as a function of forest age. We fit empirical models to chronosequences of forest inventory data at two scales: a coarse-scale ecosystem classification (ecosections) and forest types (potential vegetation) within ecosections. We hypothesized that analysis at the finer...

  3. River flow and riparian vegetation dynamics - implications for management of the Yampa River through Dinosaur National Monument

    Science.gov (United States)

    Scott, Michael L; Friedman, Jonathan M.

    2018-01-01

    This report addresses the relation between flow of the Yampa River and occurrence of herbaceous and woody riparian vegetation in Dinosaur National Monument (DINO) with the goal of informing management decisions related to potential future water development. The Yampa River in DINO flows through diverse valley settings, from the relatively broad restricted meanders of Deerlodge Park to narrower canyons, including debris fan-affected reaches in the upper Yampa Canyon and entrenched meanders in Harding Hole and Laddie Park. Analysis of occurrence of all plant species measured in 1470 quadrats by multiple authors over the last 24 years shows that riparian vegetation along the Yampa River is strongly related to valley setting and geomorphic surfaces, defined here as active channel, active floodplain, inactive floodplain, and upland. Principal Coordinates Ordination arrayed quadrats and species along gradients of overall cover and moisture availability, from upland and inactive floodplain quadrats and associated xeric species like western wheat grass (Pascopyrum smithii), cheatgrass (Bromus tectorum), and saltgrass (Distichlis spicata) to active channel and active floodplain quadrats supporting more mesic species including sandbar willow (Salix exigua), wild licorice (Glycyrrhiza lepidota), and cordgrass (Spartina spp.). Indicator species analysis identified plants strongly correlated with geomorphic surfaces. These species indicate state changes in geomorphic surfaces, such as the conversion of active channel to floodplain during channel narrowing. The dominant woody riparian species along the Yampa River are invasive tamarisk (Tamarix ramosissima), and native Fremont cottonwood (Populus deltoides ssp. wislizenii), box elder (Acer negundo L. var. interius), and sandbar willow (Salix exigua). These species differ in tolerance of drought, salinity, inundation, flood disturbance and shade, and in seed size, timing of seed dispersal and ability to form root sprouts. These

  4. Spatio-temporal dynamics of the tropical rain forest

    Energy Technology Data Exchange (ETDEWEB)

    Chave, J. [CEN Saclay, Gif-sur-Yvette (France). Service de Physique de l' Etat Condense

    2000-07-01

    Mechanisms which drive the dynamics of forest ecosystems are complex, from seedling establishment to pollination, and seed dispersal by animals, running water or wind. These processes are more complex when the ecosystem shelters a large number of species and of vegetative forms, as it is the case in the tropical rainforest. To take them into account, we must develop and use models. I present a review of the fundamental mechanisms for the of a natural forest dynamics - photosynthesis, tree growth, recruitment and mortality - as well as a description of the past and of the present of tropical rainforests. This information is used to develop a spatially-explicit and individual-based forest model. Simplified models are deduced from it, and they serve to address more specific issues, such as the resilience of the forest to climate disturbances, or savanna-forest dynamics. The last topic is related to the spatio-temporal description of tropical plant biodiversity. A detailed introduction to the problem is provided, and models accounting for the maintenance of diversity are compared. These models include non spatial as well a spatial approaches (branching anihilating random walks and voter model with mutation). (orig.)

  5. Estimating Carbon Dynamics in an Intact Lowland Mixed Dipterocarp Forest Using a Forest Carbon Model

    Directory of Open Access Journals (Sweden)

    Jongyeol Lee

    2017-04-01

    Full Text Available Intact dipterocarp forests in Asia act as crucial carbon (C reservoirs, and it is therefore important to investigate the C dynamics in these forests. We estimated C dynamics, together with net ecosystem production (NEP, in an intact tropical dipterocarp forest of Brunei Darussalam. Fifty-four simulation units (plots; 20 m × 20 m were established and initial C stocks were determined via direct field measurement. The C dynamics were annually simulated with a regression model and the Forest Biomass and Dead organic matter Carbon (FBDC model. The initial C stock (Mg C·ha−1 of biomass, litter, dead wood and mineral soil were 213.1 ± 104.8, 2.0 ± 0.8, 31.3 ± 38.8, and 80.7 ± 15.5, respectively. Their annual changes (Mg C·ha−1·year−1 were 3.2 ± 1.1, 0.2 ± 0.2, −3.7 ± 6.1, and −0.3 ± 1.1, respectively. NEP was −0.6 ± 6.1 Mg C·ha−1·year−1, showing large heterogeneity among the plots. The initial C stocks of biomass and dead wood, biomass turnover rates and dead wood decay rates were elucidated as dominant factors determining NEP in a sensitivity analysis. Accordingly, investigation on those input data can constrain an uncertainty in determining NEP in the intact tropical forests.

  6. Forest fragmentation and bird community dynamics: inference at regional scales

    Science.gov (United States)

    Thierry Boulinier; James D. Nichols; James E. Hines; John R. Sauer; Curtis H. Flather; Kenneth H. Pollock

    2001-01-01

    With increasing fragmentation of natural areas and a dramatic reduction of forest cover in several parts of the world, quantifying the impact of such changes on species richness and community dynamics has been a subject of much concern. Here, we tested whether in more fragmented landscapes there was a lower number of area-sensitive species and higher local extinction...

  7. Regional biomass stores and dynamics in forests of coastal Alaska

    Science.gov (United States)

    Mikhaill A. Yatskov; Mark E. Harmon; Olga N. Krankina; Tara M. Barrett; Kevin R. Dobelbower; Andrew N. Gray; Becky Fasth; Lori Trummer; Toni L. Hoyman; Chana M. Dudoit

    2015-01-01

    Coastal Alaska is a vast forested region (6.2 million ha) with the potential to store large amounts of carbon in live and dead biomass thus influencing continental and global carbon dynamics. The main objectives of this study were to assess regional biomass stores, examine the biomass partitioning between live and dead pools, and evaluate the effect of disturbance on...

  8. Environmental drivers of deadwood dynamics in woodlands and forests

    Science.gov (United States)

    M. Garbarino; R. Marzano; John Shaw; J. N. Long

    2015-01-01

    Deadwood dynamics play a key role in many forest ecosystems. Understanding the mechanisms involved in the accumulation and depletion of deadwood can enhance our understanding of fundamental processes such as carbon sequestration and disturbance regimes, allowing better predictions of future changes related to alternative management and climate scenarios. A...

  9. Woody debris dynamics in Interior West forests and woodlands

    Science.gov (United States)

    John D. Shaw; James Long; Raffaella Marzano; Matteo Garbarino

    2012-01-01

    Managers are interested in the dynamics of down woody material because of its role as a fuel component, a feature of wildlife habitat, a carbon pool, and other characteristics. We analyzed nearly 9,000 plots from the Interior West, spanning the range from sparse juniper and mesquite woodland to dense spruce-fir forests, in order to characterize down woody material as...

  10. A review of malaria transmission dynamics in forest ecosystems

    Science.gov (United States)

    2014-01-01

    Malaria continues to be a major health problem in more than 100 endemic countries located primarily in tropical and sub-tropical regions around the world. Malaria transmission is a dynamic process and involves many interlinked factors, from uncontrollable natural environmental conditions to man-made disturbances to nature. Almost half of the population at risk of malaria lives in forest areas. Forests are hot beds of malaria transmission as they provide conditions such as vegetation cover, temperature, rainfall and humidity conditions that are conducive to distribution and survival of malaria vectors. Forests often lack infrastructure and harbor tribes with distinct genetic traits, socio-cultural beliefs and practices that greatly influence malaria transmission dynamics. Here we summarize the various topographical, entomological, parasitological, human ecological and socio-economic factors, which are crucial and shape malaria transmission in forested areas. An in-depth understanding and synthesis of the intricate relationship of these parameters in achieving better malaria control in various types of forest ecosystems is emphasized. PMID:24912923

  11. Modeling forest dynamics along climate gradients in Bolivia

    Science.gov (United States)

    Seiler, C.; Hutjes, R. W. A.; Kruijt, B.; Quispe, J.; Añez, S.; Arora, V. K.; Melton, J. R.; Hickler, T.; Kabat, P.

    2014-05-01

    Dynamic vegetation models have been used to assess the resilience of tropical forests to climate change, but the global application of these modeling experiments often misrepresents carbon dynamics at a regional level, limiting the validity of future projections. Here a dynamic vegetation model (Lund Potsdam Jena General Ecosystem Simulator) was adapted to simulate present-day potential vegetation as a baseline for climate change impact assessments in the evergreen and deciduous forests of Bolivia. Results were compared to biomass measurements (819 plots) and remote sensing data. Using regional parameter values for allometric relations, specific leaf area, wood density, and disturbance interval, a realistic transition from the evergreen Amazon to the deciduous dry forest was simulated. This transition coincided with threshold values for precipitation (1400 mm yr-1) and water deficit (i.e., potential evapotranspiration minus precipitation) (-830 mm yr-1), beyond which leaf abscission became a competitive advantage. Significant correlations were found between modeled and observed values of seasonal leaf abscission (R2 = 0.6, p days. Decreasing rainfall trends were simulated to reduce GPP in the Amazon. The current model setup provides a baseline for assessing the potential impacts of climate change in the transition zone from wet to dry tropical forests in Bolivia.

  12. Forests

    International Nuclear Information System (INIS)

    Melin, J.

    1997-01-01

    Forests have the capacity to trap and retain radionuclides for a substantial period of time. The dynamic behaviour of nutrients, pollution and radionuclides in forests is complex. The rotation period of a forest stand in the Nordic countries is about 100 years, whilst the time for decomposition of organic material in a forest environment can be several hundred years. This means that any countermeasure applied in the forest environment must have an effect for several decades, or be reapplied continuously for long periods of time. To mitigate the detrimental effect of a contaminated forest environment on man, and to minimise the economic loss in trade of contaminated forest products, it is necessary to understand the mechanisms of transfer of radionuclides through the forest environment. It must also be stressed that any countermeasure applied in the forest environment must be evaluated with respect to long, as well as short term, negative effects, before any decision about remedial action is taken. Of the radionuclides studied in forests in the past, radiocaesium has been the main contributor to dose to man. In this document, only radiocaesium will be discussed since data on the impact of other radionuclides on man are too scarce for a proper evaluation. (EG)

  13. Water quality and fish dynamics in forested wetlands associated with an oxbow lake

    Science.gov (United States)

    Andrews, Caroline S.; Miranda, Leandro E.; Kroger, Robert

    2015-01-01

    Forested wetlands represent some of the most distinct environments in the Lower Mississippi Alluvial Valley. Depending on season, water in forested wetlands can be warm, stagnant, and oxygen-depleted, yet may support high fish diversity. Fish assemblages in forested wetlands are not well studied because of difficulties in sampling heavily structured environments. During the April–July period, we surveyed and compared the water quality and assemblages of small fish in a margin wetland (forested fringe along a lake shore), contiguous wetland (forested wetland adjacent to a lake), and the open water of an oxbow lake. Dissolved-oxygen levels measured hourly 0.5 m below the surface were higher in the open water than in either of the forested wetlands. Despite reduced water quality, fish-species richness and catch rates estimated with light traps were greater in the forested wetlands than in the open water. The forested wetlands supported large numbers of fish and unique fish assemblages that included some rare species, likely because of their structural complexity. Programs developed to refine agricultural practices, preserve riparian zones, and restore lakes should include guidance to protect and reestablish forested wetlands.

  14. Forest fragmentation and bird community dynamics: inference at regional scales

    Science.gov (United States)

    Boulinier, T.; Nichols, J.D.; Hines, J.E.; Sauer, J.R.; Flather, C.H.; Pollock, K.H.

    2001-01-01

    With increasing fragmentation of natural areas and a dramatic reduction of forest cover in several parts of the world, quantifying the impact of such changes on species richness and community dynamics has been a subject of much concern. Here, we tested whether in more fragmented landscapes there was a lower number of area-sensitive species and higher local extinction and turnover rates, which could explain higher temporal variability in species richness. To investigate such potential landscape effects at a regional scale, we merged two independent, large-scale monitoring efforts: the North American Breeding Bird Survey (BBS) and the Land Use and Land Cover Classification data from the U.S. Geological Survey. We used methods that accounted for heterogeneity in the probability of detecting species to estimate species richness and temporal changes in the bird communities for BBS routes in three mid-Atlantic U.S. states. Forest breeding bird species were grouped prior to the analyses into area-sensitive and non-area-sensitive species according to previous studies. We tested predictions relating measures of forest structure at one point in time (1974) to species richness at that time and to parameters of forest bird community change over the following 22-yr-period (1975-1996). We used the mean size of forest patches to characterize landscape structure, as high correlations among landscape variables did not allow us to disentangle the relative roles of habitat fragmentation per se and habitat loss. As predicted, together with lower species richness for area-sensitive species on routes surrounded by landscapes with lower mean forest-patch size, we found higher mean year-to-year rates of local extinction. Moreover, the mean year-to-year rates of local turnover (proportion of locally new species) for area-sensitive species were also higher in landscapes with lower mean forest-patch size. These associations were not observed for the non-area-sensitive species group. These

  15. Decomposition of leaf litter from a native tree and an actinorhizal invasive across riparian habitats.

    Science.gov (United States)

    Harner, Mary J; Crenshaw, Chelsea L; Abelho, Manuela; Stursova, Martina; Shah, Jennifer J Follstad; Sinsabaugh, Robert L

    2009-07-01

    Dynamics of nutrient exchange between floodplains and rivers have been altered by changes in flow management and proliferation of nonnative plants. We tested the hypothesis that the nonnative, actinorhizal tree, Russian olive (Elaeagnus angustifolia), alters dynamics of leaf litter decomposition compared to native cottonwood (Populus deltoides ssp. wislizeni) along the Rio Grande, a river with a modified flow regime, in central New Mexico (U.S.A.). Leaf litter was placed in the river channel and the surface and subsurface horizons of forest soil at seven riparian sites that differed in their hydrologic connection to the river. All sites had a cottonwood canopy with a Russian olive-dominated understory. Mass loss rates, nutrient content, fungal biomass, extracellular enzyme activities (EEA), and macroinvertebrate colonization were followed for three months in the river and one year in forests. Initial nitrogen (N) content of Russian olive litter (2.2%) was more than four times that of cottonwood (0.5%). Mass loss rates (k; in units of d(-1)) were greatest in the river (Russian olive, k = 0.0249; cottonwood, k = 0.0226), intermediate in subsurface soil (Russian olive, k = 0.0072; cottonwood, k = 0.0031), and slowest on the soil surface (Russian olive, k = 0.0034; cottonwood, k = 0.0012) in a ratio of about 10:2:1. Rates of mass loss in the river were indistinguishable between species and proportional to macroinvertebrate colonization. In the riparian forest, Russian olive decayed significantly faster than cottonwood in both soil horizons. Terrestrial decomposition rates were related positively to EEA, fungal biomass, and litter N, whereas differences among floodplain sites were related to hydrologic connectivity with the river. Because nutrient exchanges between riparian forests and the river have been constrained by flow management, Russian olive litter represents a significant annual input of N to riparian forests, which now retain a large portion of slowly

  16. Examining Pseudotsuga menziesii biomass change dynamics through succession using a regional forest inventory system

    Science.gov (United States)

    David M. Bell; Andrew N. Gray

    2015-01-01

    Models of forest succession provide an appealing conceptual framework for understanding forest dynamics, but uncertainty in the degree to which patterns are regionally consistent might limit the application of successional theory in forest management. Remeasurements of forest inventory networks provide an opportunity to assess this consistency, improving our...

  17. Extinction threshold for spatial forest dynamics with height structure.

    Science.gov (United States)

    Garcia-Domingo, Josep L; Saldaña, Joan

    2011-05-07

    We present a pair-approximation model for spatial forest dynamics defined on a regular lattice. The model assumes three possible states for a lattice site: empty (gap site), occupied by an immature tree, and occupied by a mature tree, and considers three nonlinearities in the dynamics associated to the processes of light interference, gap expansion, and recruitment. We obtain an expression of the basic reproduction number R(0) which, in contrast to the one obtained under the mean-field approach, uses information about the spatial arrangement of individuals close to extinction. Moreover, we analyze the corresponding survival-extinction transition of the forest and the spatial correlations among gaps, immature and mature trees close to this critical point. Predictions of the pair-approximation model are compared with those of a cellular automaton. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Phosphorus retention in riparian buffers: review of their efficiency.

    Science.gov (United States)

    Hoffmann, Carl Christian; Kjaergaard, Charlotte; Uusi-Kämppä, Jaana; Hansen, Hans Christian Bruun; Kronvang, Brian

    2009-01-01

    Ground water and surface water interactions are of fundamental importance for the biogeochemical processes governing phosphorus (P) dynamics in riparian buffers. The four most important conceptual hydrological pathways for P losses from and P retention in riparian buffers are reviewed in this paper: (i) The diffuse flow path with ground water flow through the riparian aquifer, (ii) the overland flow path across the riparian buffer with water coming from adjacent agricultural fields, (iii) irrigation of the riparian buffer with tile drainage water from agricultural fields where disconnected tile drains irrigate the riparian buffer, and (iv) inundation of the riparian buffer (floodplain) with river water during short or longer periods. We have examined how the different flow paths in the riparian buffer influence P retention mechanisms theoretically and from empirical evidence. The different hydrological flow paths determine where and how water-borne P compounds meet and interact with iron and aluminum oxides or other minerals in the geochemical cycling of P in the complex and dynamic environment that constitutes a riparian buffer. The main physical process in the riparian buffer-sedimentation-is active along several flow paths and may account for P retention rates of up to 128 kg P ha(-1) yr(-1), while plant uptake may temporarily immobilize up to 15 kg P ha(-1) yr(-1). Retention of dissolved P in riparian buffers is not as pronounced as retention of particulate P and is often below 0.5 kg P ha(-1) yr(-1). Several studies show significant release of dissolved P (i.e., up to 8 kg P ha(-1) yr(-1)).

  19. Importance of riparian remnants for frog species diversity in a highly fragmented rainforest.

    Science.gov (United States)

    Rodríguez-Mendoza, Clara; Pineda, Eduardo

    2010-12-23

    Tropical forests undergo continuous transformation to other land uses, resulting in landscapes typified by forest fragments surrounded by anthropogenic habitats. Small forest fragments, specifically strip-shaped remnants flanking streams (referred to as riparian remnants), can be particularly important for the maintenance and conservation of biodiversity within highly fragmented forests. We compared frog species diversity between riparian remnants, other forest fragments and cattle pastures in a tropical landscape in Los Tuxtlas, Mexico. We found similar species richness in the three habitats studied and a similar assemblage structure between riparian remnants and forest fragments, although species composition differed by 50 per cent. Frog abundance was halved in riparian remnants compared with forest fragments, but was twice that found in pastures. Our results suggest that riparian remnants play an important role in maintaining a portion of frog species diversity in a highly fragmented forest, particularly during environmentally stressful (hot and dry) periods. In this regard, however, the role of riparian remnants is complementary, rather than substitutive, with respect to the function of other forest fragments within the fragmented forest.

  20. Temporal dynamics of a subtropical urban forest in San Juan, Puerto Rico, 2001-2010

    Science.gov (United States)

    J. M. Tucker Lima; C. L. Staudhammer; T. J. Brandeis; F. J. Escobedo; W. Zipperer

    2013-01-01

    Several studies report urban tree growth and mortality rates as well as species composition, structural dynamics, and other characteristics of urban forests in mostly temperate, inland urban areas. Temporal dynamics of urban forests in subtropical and tropical forest regions are, until now, little explored and represent a new and important direction for study and...

  1. Forest canopy temperatures: dynamics, controls, and relationships with ecosystem fluxes

    Science.gov (United States)

    Still, C. J.; Griffith, D.; Kim, Y.; Law, B. E.; Hanson, C. V.; Kwon, H.; Schulze, M.; Detto, M.; Pau, S.

    2017-12-01

    Temperature strongly affects enzymatic reactions, ecosystem biogeochemistry, and species distributions. Although most focus is on air temperature, the radiative or skin temperature of plants is more relevant. Canopy skin temperature dynamics reflect biophysical, physiological, and anatomical characteristics and interactions with the environment, and can be used to examine forest responses to stresses like droughts and heat waves. Thermal infrared (TIR) imaging allows for extensive temporal and spatial sampling of canopy temperatures, particularly compared to spot measurements using thermocouples. We present results of TIR imaging of forest canopies at eddy covariance flux tower sites in the US Pacific Northwest and in Panama. These forests range from an old-growth temperate rainforest to a second growth semi-arid pine forest to a semi-deciduous tropical forest. Canopy temperature regimes at these sites are highly variable. Canopy temperatures at all forest sites displayed frequent departures from air temperature, particularly during clear sky conditions, with elevated canopy temperatures during the day and depressed canopy temperatures at night compared to air temperature. Comparison of canopy temperatures to fluxes of carbon dioxide, water vapor, and energy reveals stronger relationships than those found with air temperature. Daytime growing season net ecosystem exchange at the pine forest site is better explained by canopy temperature (r2 = 0.61) than air temperature (r2 = 0.52). At the semi-deciduous tropical forest, canopy photosynthesis is highly correlated with canopy temperature (r2 = 0.51), with a distinct optimum temperature for photosynthesis ( 31 °C) that agrees with leaf-level measurements. During the peak of one heat wave at an old-growth temperate rainforest, hourly averaged air temperature exceeded 35 °C, 10 °C above average. Peak hourly canopy temperature approached 40 °C, and leaf-to-air vapor pressure deficit exceeded 6 kPa. These extreme

  2. Development and application of multi-proxy indices of land use change for riparian soils in southern New England, USA.

    Science.gov (United States)

    Ricker, M C; Donohue, S W; Stolt, M H; Zavada, M S

    2012-03-01

    Understanding the effects of land use on riparian systems is dependent upon the development of methodologies to recognize changes in sedimentation related to shifts in land use. Land use trends in southern New England consist of shifts from forested precolonial conditions, to colonial and agrarian land uses, and toward modern industrial-urban landscapes. The goals of this study were to develop a set of stratigraphic indices that reflect these land use periods and to illustrate their applications. Twenty-four riparian sites from first- and second-order watersheds were chosen for study. Soil morphological features, such as buried surface horizons (layers), were useful to identify periods of watershed instability. The presence of human artifacts and increases in heavy metal concentration above background levels, were also effective indicators of industrial-urban land use periods. Increases and peak abundance of non-arboreal weed pollen (Ambrosia) were identified as stratigraphic markers indicative of agricultural land uses. Twelve 14C dates from riparian soils indicated that the rise in non-arboreal pollen corresponds to the start of regional deforestation (AD 1749 +/- 56 cal yr; mean +/- 2 SD) and peak non-arboreal pollen concentration corresponds to maximum agricultural land use (AD 1820 +/- 51 cal yr). These indices were applied to elucidate the impact of land use on riparian sedimentation and soil carbon (C) dynamics. This analysis indicated that the majority of sediment and soil organic carbon (SOC) stored in regional riparian soils is of postcolonial origins. Mean net sedimentation rates increased -100-fold during postcolonial time periods, and net SOC sequestration rates showed an approximate 200-fold increase since precolonial times. These results suggest that headwater riparian zones have acted as an effective sink for alluvial sediment and SOC associated with postcolonial land use.

  3. Riparian zone controls on base cation concentrations in boreal streams

    Science.gov (United States)

    Ledesma, J. L. J.; Grabs, T.; Futter, M. N.; Bishop, K. H.; Laudon, H.; Köhler, S. J.

    2013-01-01

    Forest riparian zones are a major in control of surface water quality. Base cation (BC) concentrations, fluxes, and cycling in the riparian zone merit attention because of increasing concern of negative consequences for re-acidification of surface waters from future climate and forest harvesting scenarios. We present a two-year study of BC and silica (Si) flow-weighted concentrations from 13 riparian zones and 14 streams in a boreal catchment in northern Sweden. The Riparian Flow-Concentration Integration Model (RIM) was used to estimate riparian zone flow-weighted concentrations and tested to predict the stream flow-weighted concentrations. Spatial variation in BC and Si concentrations as well as in flow-weighted concentrations was related to differences in Quaternary deposits, with the largest contribution from lower lying silty sediments and the lowest contribution from wetland areas higher up in the catchment. Temporal stability in the concentrations of most elements, a remarkably stable Mg / Ca ratio in the soil water and a homogeneous mineralogy suggest that the stable patterns found in the riparian zones are a result of distinct mineralogical upslope groundwater signals integrating the chemical signals of biological and chemical weathering. Stream water Mg / Ca ratio indicates that the signal is subsequently maintained in the streams. RIM gave good predictions of Ca, Mg, and Na flow-weighted concentrations in headwater streams. The difficulty in modelling K and Si suggests a stronger biogeochemical influence on these elements. The observed chemical dilution effect with flow in the streams was related to variation in groundwater levels and element concentration profiles in the riparian zones. This study provides a first step toward specific investigations of the vulnerability of riparian zones to changes induced by forest management or climate change, with focus on BC or other compounds.

  4. Drivers of forest cover dynamics in smallholder farming systems: the case of northwestern Vietnam.

    Science.gov (United States)

    Jadin, Isaline; Vanacker, Veerle; Hoang, Huong Thi Thu

    2013-04-01

    The national-scale forest recovery of Vietnam started in the early 1990s and is associated with a shift from net deforestation to net reforestation. Large disparities in forest cover dynamics are, however, observed at the local scale. This study aims to unravel the mechanisms driving forest cover change for a mountainous region located in northwest Vietnam. Statistical analyses were used to explore the association between forest cover change and household characteristics. In Sa Pa district, deforestation rates are decreasing, but forest degradation continues at similar rates. Deforestation is not necessarily associated with impoverished ethnic communities or high levels of subsistence farming, and the largest forest cover dynamics are found in villages with the best socio-economic conditions. Our empirical study does not provide strong evidence of a dominant role of agriculture in forest cover dynamics. It shows that empirical studies on local-scale forest dynamics remain important to unravel the complexity of human-environment interactions.

  5. Reducing uncertainty for estimating forest carbon stocks and dynamics using integrated remote sensing, forest inventory and process-based modeling

    Science.gov (United States)

    Poulter, B.; Ciais, P.; Joetzjer, E.; Maignan, F.; Luyssaert, S.; Barichivich, J.

    2015-12-01

    Accurately estimating forest biomass and forest carbon dynamics requires new integrated remote sensing, forest inventory, and carbon cycle modeling approaches. Presently, there is an increasing and urgent need to reduce forest biomass uncertainty in order to meet the requirements of carbon mitigation treaties, such as Reducing Emissions from Deforestation and forest Degradation (REDD+). Here we describe a new parameterization and assimilation methodology used to estimate tropical forest biomass using the ORCHIDEE-CAN dynamic global vegetation model. ORCHIDEE-CAN simulates carbon uptake and allocation to individual trees using a mechanistic representation of photosynthesis, respiration and other first-order processes. The model is first parameterized using forest inventory data to constrain background mortality rates, i.e., self-thinning, and productivity. Satellite remote sensing data for forest structure, i.e., canopy height, is used to constrain simulated forest stand conditions using a look-up table approach to match canopy height distributions. The resulting forest biomass estimates are provided for spatial grids that match REDD+ project boundaries and aim to provide carbon estimates for the criteria described in the IPCC Good Practice Guidelines Tier 3 category. With the increasing availability of forest structure variables derived from high-resolution LIDAR, RADAR, and optical imagery, new methodologies and applications with process-based carbon cycle models are becoming more readily available to inform land management.

  6. Dynamic analysis and pattern visualization of forest fires.

    Science.gov (United States)

    Lopes, António M; Tenreiro Machado, J A

    2014-01-01

    This paper analyses forest fires in the perspective of dynamical systems. Forest fires exhibit complex correlations in size, space and time, revealing features often present in complex systems, such as the absence of a characteristic length-scale, or the emergence of long range correlations and persistent memory. This study addresses a public domain forest fires catalogue, containing information of events for Portugal, during the period from 1980 up to 2012. The data is analysed in an annual basis, modelling the occurrences as sequences of Dirac impulses with amplitude proportional to the burnt area. First, we consider mutual information to correlate annual patterns. We use visualization trees, generated by hierarchical clustering algorithms, in order to compare and to extract relationships among the data. Second, we adopt the Multidimensional Scaling (MDS) visualization tool. MDS generates maps where each object corresponds to a point. Objects that are perceived to be similar to each other are placed on the map forming clusters. The results are analysed in order to extract relationships among the data and to identify forest fire patterns.

  7. Width of riparian buffer and structure of adjacent plantations influence occupancy of conservation priority birds

    Science.gov (United States)

    Roger W. Perry; T. Bently Wigley; M. Anthony Melchiors; Ronald E. Thill; Philip A. Tappe; Darren A. Miller

    2011-01-01

    Conservation of biodiversity on forest landscapes dominated by plantations has become an increasingly important topic, and opportunities to maintain or enhance biodiversity within these forests need to be recognized and applied. Riparian buffers of mature forest retained along streams in managed forest landscapes offer an opportunity to enhance biodiversity across...

  8. Advances on Modelling Riparian Vegetation-Hydromorphology Interactions

    NARCIS (Netherlands)

    Solari, L.; Van Oorschot, M.; Belletti, B.; Hendriks, D.; Rinaldi, M.; Vargas-Luna, A.

    2016-01-01

    Riparian vegetation actively interacts with fluvial systems affecting river hydrodynamics, morphodynamics and groundwater. These interactions can be coupled because both vegetation and hydromorphology (i.e. the combined scientific study of hydrology and fluvial geomorphology) involve dynamic

  9. Post-wildfire recovery of riparian vegetation during a period of water scarcity in the southwestern USA

    Science.gov (United States)

    D. Max Smith; Deborah M. Finch; Christian Gunning; Roy Jemison; Jeffrey F. Kelly

    2009-01-01

    Wildland fires occur with increasing frequency in southwestern riparian forests, yet little is known about the effects of fire on populations of native and exotic vegetation. From 2003 to 2006, we monitored recovering woody vegetation in wildfire sites in the bosque (riparian forest) along the Middle Rio Grande of central New Mexico, USA. To examine recovery potential...

  10. Simulated impacts of insect defoliation on forest carbon dynamics

    International Nuclear Information System (INIS)

    Medvigy, D; Clark, K L; Skowronski, N S; Schäfer, K V R

    2012-01-01

    Many temperate and boreal forests are subject to insect epidemics. In the eastern US, over 41 million meters squared of tree basal area are thought to be at risk of gypsy moth defoliation. However, the decadal-to-century scale implications of defoliation events for ecosystem carbon dynamics are not well understood. In this study, the effects of defoliation intensity, periodicity and spatial pattern on the carbon cycle are investigated in a set of idealized model simulations. A mechanistic terrestrial biosphere model, ecosystem demography model 2, is driven with observations from a xeric oak–pine forest located in the New Jersey Pine Barrens. Simulations indicate that net ecosystem productivity (equal to photosynthesis minus respiration) decreases linearly with increasing defoliation intensity. However, because of interactions between defoliation and drought effects, aboveground biomass exhibits a nonlinear decrease with increasing defoliation intensity. The ecosystem responds strongly with both reduced productivity and biomass loss when defoliation periodicity varies from 5 to 15 yr, but exhibits a relatively weak response when defoliation periodicity varies from 15 to 60 yr. Simulations of spatially heterogeneous defoliation resulted in markedly smaller carbon stocks than simulations with spatially homogeneous defoliation. These results show that gypsy moth defoliation has a large effect on oak–pine forest biomass dynamics, functioning and its capacity to act as a carbon sink. (letter)

  11. Growth Dynamics of Araucaria after Management Interventions in Natural Forest

    Directory of Open Access Journals (Sweden)

    Régis Villanova Longhi

    2018-02-01

    Full Text Available ABSTRACT The objective of this study was to evaluate the effect of selective logging on the growth dynamics of Araucaria angustifolia in a natural forest of Rio Grande do Sul state, Brazil. Treatments were based on percentage reduction of the basal area per DBH class, namely, T0 (control = 0%; T1 (light selective logging = reduction of 20-30%; T2 (moderate selective logging = reduction of 40-50%. Data were obtained prior to the management interventions and four, eight and 13 years after selective logging. Changes between treatments were assessed using the following parameters: absolute density, absolute dominance, importance value index, and growth rates. Results show that population reduction and canopy opening provided greater recruitment and higher growth rates for araucaria in the management treatments (T1 and T2 compared with those of the control treatment (T0. These results reinforce that management practices are necessary for the continuous development of araucaria in this forest formation.

  12. REMM: The Riparian Ecosystem Management Model

    Energy Technology Data Exchange (ETDEWEB)

    Lowrance, R.; Altier, L.S.; Williams, R.G.; Inamdar, S.P.; Sheridan, J.M.; Bosch, D.D.; Hubbard, R.K.; Thomas, D.L.

    2000-03-01

    Riparian buffer zones are effective in mitigating nonpoint source pollution and have been recommended as a best management practice (BMP). The Riparian Ecosystem Management Model (REMM) has been developed for researchers and natural resource agencies as a modeling tool that can help quantify the water quality benefits of riparian buffers under varying site conditions. Processes simulated in REMM include surface and subsurface hydrology; sediment transport and deposition; carbon, nitrogen, and phosphorus transport, removal, and cycling; and vegetation growth. Management options, such as vegetation type, size of the buffer zone, and biomass harvesting also can be simulated. REMM can be used in conjunction with upland models, empirical data, or estimated loadings to examine scenarios of buffer zone design for a hillslope. Evaluation of REMM simulations with field observations shows generally good agreement between simulated and observed data for groundwater nitrate concentrations and water table depths in a mature riparian forest buffer. Sensitivity analysis showed that changes that influenced the water balance or soil moisture storage affected the streamflow output. Parameter changes that influence either hydrology or rates of nutrient cycling affected total N transport and plant N uptake.

  13. Stream channel designs for riparian and wet meadow rangelands in the southwestern United States

    Science.gov (United States)

    Roy Jemison; Daniel G. Neary

    2000-01-01

    Inappropriate land uses have degraded wetland and riparian ecosystems throughout the Southwestern United States. In 1996, the Cibola National Forest in New Mexico implemented a channel relocation project, as part of a road improvement project, to determine the feasibility of restoring wet meadow and riparian ecosystems degraded by inappropriately located roads and...

  14. Riparian restoration in the Southwest: Species selection, propagation, planting methods, and case studies

    Science.gov (United States)

    David Dreesen; John Harrington; Tom Subirge; Pete Stewart; Greg Fenchel

    2002-01-01

    Riparian plant communities, though small in overall area, are among the most valuable natural areas in the Southwest. The causes of degradation of southwestern riparian zones range from excessive cattle and elk grazing in montane watersheds to invasive woody exotic species and lack of natural flooding in the cottonwood forests, "bosque," of low elevation...

  15. Distribution and dynamics of mangrove forests of South Asia.

    Science.gov (United States)

    Giri, Chandra; Long, Jordan; Abbas, Sawaid; Murali, R Mani; Qamer, Faisal M; Pengra, Bruce; Thau, David

    2015-01-15

    Mangrove forests in South Asia occur along the tidal sea edge of Bangladesh, India, Pakistan, and Sri Lanka. These forests provide important ecosystem goods and services to the region's dense coastal populations and support important functions of the biosphere. Mangroves are under threat from both natural and anthropogenic stressors; however the current status and dynamics of the region's mangroves are poorly understood. We mapped the current extent of mangrove forests in South Asia and identified mangrove forest cover change (gain and loss) from 2000 to 2012 using Landsat satellite data. We also conducted three case studies in Indus Delta (Pakistan), Goa (India), and Sundarbans (Bangladesh and India) to identify rates, patterns, and causes of change in greater spatial and thematic details compared to regional assessment of mangrove forests. Our findings revealed that the areal extent of mangrove forests in South Asia is approximately 1,187,476 ha representing ∼7% of the global total. Our results showed that from 2000 to 2012, 92,135 ha of mangroves were deforested and 80,461 ha were reforested with a net loss of 11,673 ha. In all three case studies, mangrove areas have remained the same or increased slightly, however, the turnover was greater than the net change. Both, natural and anthropogenic factors are responsible for the change and turnover. The major causes of forest cover change are similar throughout the region; however, specific factors may be dominant in specific areas. Major causes of deforestation in South Asia include (i) conversion to other land use (e.g. conversion to agriculture, shrimp farms, development, and human settlement), (ii) over-harvesting (e.g. grazing, browsing and lopping, and fishing), (iii) pollution, (iv) decline in freshwater availability, (v) floodings, (vi) reduction of silt deposition, (vii) coastal erosion, and (viii) disturbances from tropical cyclones and tsunamis. Our analysis in the region's diverse socio-economic and

  16. Climate change impact on landscape fire and forest biomass dynamics

    International Nuclear Information System (INIS)

    Li, C.

    2004-01-01

    The aim of this study was to improve current understandings of fire regimes. The estimation of biomass dynamics at the stand scale is essential for understanding landscape scale biomass dynamics, particularly in order to understand the potential effects of fire regimes. This study presented a synthesis of research results obtained from stand scale studies together with fire behaviour and weather variables. Landscape structure, topography and climate conditions were also considered. Integration of the data was conducted with the SEM-LAND model, a spatially explicit model for landscape dynamics. Equations for the model were presented, including fire initiation and spread, as well as a lightning fire process and simulated fire suppression. Results indicated that fire suppression could alter the distribution of fire sizes. The effect of tree and stand mortality on forest biomass estimates was also discussed along with the impact of climate change on fire regimes. Results indicate that fire activities are likely to increase. Results also demonstrate that fire frequency and size distribution are correlated without human intervention. Theoretical negative exponential forest age distribution is not always supported by empirical observations. Point-based fire frequency and fire cycle definitions are special cases from a computational perspective. Detection of quantitative interrelationships may simplify preconditions for estimating fire regimes, and serve as a means to address incomplete empirical observations. 12 refs., 3 figs

  17. DRAINMOD-FOREST: Integrated Modeling of Hydrology, Soil Carbon and Nitrogen Dynamics, and Plant Growth for Drained Forests.

    Science.gov (United States)

    Tian, Shiying; Youssef, Mohamed A; Skaggs, R Wayne; Amatya, Devendra M; Chescheir, G M

    2012-01-01

    We present a hybrid and stand-level forest ecosystem model, DRAINMOD-FOREST, for simulating the hydrology, carbon (C) and nitrogen (N) dynamics, and tree growth for drained forest lands under common silvicultural practices. The model was developed by linking DRAINMOD, the hydrological model, and DRAINMOD-N II, the soil C and N dynamics model, to a forest growth model, which was adapted mainly from the 3-PG model. The forest growth model estimates net primary production, C allocation, and litterfall using physiology-based methods regulated by air temperature, water deficit, stand age, and soil N conditions. The performance of the newly developed DRAINMOD-FOREST model was evaluated using a long-term (21-yr) data set collected from an artificially drained loblolly pine ( L.) plantation in eastern North Carolina, USA. Results indicated that the DRAINMOD-FOREST accurately predicted annual, monthly, and daily drainage, as indicated by Nash-Sutcliffe coefficients of 0.93, 0.87, and 0.75, respectively. The model also predicted annual net primary productivity and dynamics of leaf area index reasonably well. Predicted temporal changes in the organic matter pool on the forest floor and in forest soil were reasonable compared to published literature. Both predicted annual and monthly nitrate export were in good agreement with field measurements, as indicated by Nash-Sutcliffe coefficients above 0.89 and 0.79 for annual and monthly predictions, respectively. This application of DRAINMOD-FOREST demonstrated its capability for predicting hydrology and C and N dynamics in drained forests under limited silvicultural practices. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  18. Nitrogen dynamics in subtropical fringe and basin mangrove forests inferred from stable isotopes.

    Science.gov (United States)

    Reis, Carla Roberta Gonçalves; Nardoto, Gabriela Bielefeld; Rochelle, André Luis Casarin; Vieira, Simone Aparecida; Oliveira, Rafael Silva

    2017-03-01

    Mangroves exhibit low species richness compared to other tropical forests, but great structural and functional diversity. Aiming to contribute to a better understanding of the functioning of mangrove forests, we investigated nitrogen (N) dynamics in two physiographic types of mangroves (fringe and basin forests) in southeastern Brazil. Because fringe forests are under great influence of tidal flushing we hypothesized that these forests would exhibit higher N cycling rates in sediment and higher N losses to the atmosphere compared to basin forests. We quantified net N mineralization and nitrification rates in sediment and natural abundance of N stable isotopes (δ 15 N) in the sediment-plant-litter system. The fringe forest exhibited higher net N mineralization rates and δ 15 N in the sediment-plant-litter system, but net nitrification rates were similar to those of the basin forest. The results of the present study suggest that fringe forests exhibit higher N availability and N cycling in sediment compared to basin forests.

  19. Riparian landscapes: Linking geodiversity with habitat and biodiversity

    Science.gov (United States)

    Chmieleski, Jana; Danzeisen, Laura

    2017-04-01

    Keywords: Oder valley, biodiversity, geodiversity River landscapes of all scales originally showed a high diversity of structures and habitats at a small spatial entity, such as the stream beds, terrasses, sand and gravel banks. This variety, with a lot of different elements, patches and patterns, represents not only a variety of geoelements or geomorhological features but also a large biodiversity, both of habitats and species. Riparian landscapes are both, a natural as well as a geoheritage, often even a cultural heritage (sustainabe land use practices). Embankments, utilization for agriculture, constructions for navigation, management measures lead to a strong loss of these structures. This impacts the value of the landscape as well ecosystem functions, not only the biodiversity and the geodiversity but also the recreation function or the aesthetic values. A case study from the National Park Lower Oder Valley in the Northeastern part of Germany, wich is also part of a Geopark („Eiszeitland am Oderrand") presents the connections of the diversity of geomorphological features with biodiversity and shows the loss of features (loss of values) due to intensive utilisation by using GIS-analysis and landscape-metrics. The Northern part of the Oder valley (National Park, transnational protection area of Germany and Poland) have been modified by man since centuries but even so remained in near-natural state that allows semi-(natural) stream dynamics. While the Oder's reparian zone is marked by the stream itself, by its bayous, reed beds, periodically flooded wet meadows and by its natural riparian forest the mineral morainic plateaus are marked by semi-natural forests and dry grasslands. Two areas of different degradation states, a) near-natural and wilderness area and b) grassland area will be compared in order to identify: quantity and extent of features, relation of measure and coverage, connectivity with other features, quantity and types of habitats (with

  20. The interacting effects of ungulates and fire on forest dynamics: an analysis using the model FORSPACE

    NARCIS (Netherlands)

    Kramer, K.; Groen, T.A.; Wieren, van S.E.

    2003-01-01

    The effects of interactions between the density of ungulates and forest fires on forest dynamics were studied on an area of 1188 ha called Planken Wambuis. The vegetation consists mainly of heathland and Scots pine forest but also includes oak, beech and birch, and parts of former arable land that

  1. An ecoinformatics application for forest dynamics plot data management and sharing

    Science.gov (United States)

    Chau-Chin Lin; Abd Rahman Kassim; Kristin Vanderbilt; Donald Henshaw; Eda C. Melendez-Colom; John H. Porter; Kaoru Niiyama; Tsutomu Yagihashi; Sek Aun Tan; Sheng-Shan Lu; Chi-Wen Hsiao; Li-Wan Chang; Meei-Ru. Jeng

    2011-01-01

    Several forest dynamics plot research projects in the East-Asia Pacific region of the International Long-Term Ecological Research network actively collect long-term data, and some of these large plots are members of the Center for Tropical Forest Science network. The wealth of forest plot data presents challenges in information management to researchers. In order to...

  2. Grapevine dynamics after manual tending of juvenile stands on the Hoosier National Forest, Indiana

    Science.gov (United States)

    Robert C. Morrissey; Martin-Michel Gauthier; John A., Jr. Kershaw; Douglass F. Jacobs; Burnell C. Fischer; John R. Siefert

    2008-01-01

    Large woody vines, most notably grapevines, are a source of great concern for forest and wildlife managers in many parts of the Central Hardwood Forest Region of the United States. We examined grapevine dynamics in stands aged 21 - 35 years. The plots, located in regenerated clearcuts in the Hoosier National Forest (HNF), were evaluated for vine control, site, and tree...

  3. Effects of Forest Gaps on Litter Lignin and Cellulose Dynamics Vary Seasonally in an Alpine Forest

    Directory of Open Access Journals (Sweden)

    Han Li

    2016-01-01

    Full Text Available To understand how forest gaps and the associated canopy control litter lignin and cellulose dynamics by redistributing the winter snow coverage and hydrothermal conditions in the growing season, a field litterbag trial was conducted in the alpine Minjiang fir (Abies faxoniana Rehder and E.H. Wilson forest in a transitional area located in the upper reaches of the Yangtze River and the eastern Tibetan Plateau. Over the first year of litter decomposition, the litter exhibited absolute cellulose loss and absolute lignin accumulation except for the red birch litter. The changes in litter cellulose and lignin were significantly affected by the interactions among gap position, period and species. Litter cellulose exhibited a greater loss in the winter with the highest daily loss rate observed during the snow cover period. Both cellulose and lignin exhibited greater changes under the deep snow cover at the gap center in the winter, but the opposite pattern occurred under the closed canopy in the growing season. The results suggest that decreased snowpack seasonality due to winter warming may limit litter cellulose and lignin degradation in alpine forest ecosystems, which could further inhibit litter decomposition. As a result, the ongoing winter warming and gap vanishing would slow soil carbon sequestration from foliar litter in cold biomes.

  4. Trends of Forest Dynamics in Tiger Landscapes Across Asia

    Science.gov (United States)

    Mondal, Pinki; Nagendra, Harini

    2011-10-01

    Protected areas (PAs) are cornerstones of biodiversity conservation, but small parks alone cannot support wide-ranging species, such as the tiger. Hence, forest dynamics in the surrounding landscapes of PAs are also important to tiger conservation. Tiger landscapes often support considerable human population in proximity of the PA, sometimes within the core itself, and thus are subject to various land use activities (such as agricultural expansion and road development) driving habitat loss and fragmentation. We synthesize information from 27 journal articles in 24 tiger landscapes to assess forest-cover dynamics in tiger-range countries. Although 29% of the PAs considered in this study have negligible change in overall forest cover, approximately 71% are undergoing deforestation and fragmentation. Approximately 58% of the total case studies have human settlements within the core area. Most changes—including agricultural expansion, plantation, and farming (52%), fuelwood and fodder collection (43%), logging (38%), grazing (38%), and tourism and development (10%)—can be attributed to human impacts largely linked to the nature of the management regime. This study highlights the need for incorporating new perspectives, ideas, and lessons learned locally and across borders into management plans to ensure tiger conservation in landscapes dominated by human activities. Given the increasing isolation of most parks due to agricultural, infrastructural, and commercial developments at the periphery, it is imperative to conduct planning and evaluation at the landscape level, as well as incorporate multiple actors and institutions in planning, instead of focusing solely on conservation within the PAs as is currently the case in most tiger parks.

  5. Structure and dynamics of basin forested wetlands in North America

    International Nuclear Information System (INIS)

    Brown, S.

    1990-01-01

    Freshwater basin wetlands are found in depressions of various depths, generally in areas where precipitation exceeds evapotranspiration or where the depression intersects the water table creating groundwater seeps or springs. Forested basins are those that contain woody vegetation with the potential for reaching tree stature; they do not include woody shrub wetlands. In North America these areas are mainly in the central and eastern region. Pertinent information and reviews on the distribution, floristic composition, structure and dynamics of basin forested wetlands are summarized. The major emphasis is on freshwater wetlands, but data for saltwater wetlands mainly from Florida and tropical America are included. The external factors affecting basin wetlands or the important components of a wetlands energy signature are described as well as the distribution and floristic composition of representative basin wetlands. Sections on structural characteristics, organic matter dynamics, and nutrient cycling comprise the bulk of quantitative information. The effects of disturbances, both natural and human induced, with varying degrees of impact depending upon the intensity and on the part of the ecosystem to which the stressor is applied are evaluated. Examples of stressors in basin wetlands include water impoundment, water diversion, thermal stress from hot water, sedimentation, addition of toxic substances, addition of wastewater, oil spills, and harvesting. 86 refs., 5 figs., 11 tabs

  6. EnviroAtlas - Cleveland, OH - 51m Riparian Buffer Vegetated Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. In this community, vegetated cover is defined as Trees & Forest,...

  7. Bat activity following restoration prescribed burning in the central Appalachian Upland and riparian habitats

    Science.gov (United States)

    Austin, Lauren V.; Silvis, Alexander; Ford, W. Mark; Muthersbaugh, Michael; Powers, Karen E.

    2018-01-01

    After decades of fire suppression in eastern North America, land managers now are prioritizing prescribed fire as a management tool to restore or maintain fire-adapted vegetation communities. However, in long—fire-suppressed landscapes, such as the central and southern Appalachians, it is unknown how bats will respond to prescribed fire in both riparian and upland forest habitats. To address these concerns, we conducted zero-crossing acoustic surveys of bat activity in burned, unburned, riparian, and non-riparian areas in the central Appalachians, Virginia, USA. Burn and riparian variables had model support (ΔAICc fire differently between upland and riparian forest habitats, but overall, large landscape-level prescribed fire has a slightly positive to neutral impact on all bats species identified at our study site post—fire application.

  8. Forest insurance market participants’ game behavior in China: An analysis based on tripartite dynamic game model

    Directory of Open Access Journals (Sweden)

    Ning Ma

    2015-11-01

    Full Text Available Purpose: In forest insurance market, there are three main participants including the insurance company, the forest farmer and the government. As different participant has different benefit object, there will be a complex and dynamic game relationship among all participants. The purpose of this paper is to make the game relationship among all participants in forest insurance market clear, and then to put forward some policy suggestions on the implementation of forest insurance from the view of game theory. Design/methodology/approach: Firstly, the static game model between the insurance company and the forest farmer is set up. According to the result of static game model, it’s difficult to implement forest insurance without government. Secondly, the tripartite dynamic game model among the government, the insurance company and the forest farmer is proposed, and the equilibrium solution of tripartite dynamic game model is acquired. Finally, the behavioral characteristics of all participants are analyzed according to the equilibrium solution of tripartite dynamic game model. Findings: the government’s allowance will be an important positive factor to implement forest insurance. The loss of the insurance company, which the lower insurance premium brings, can be compensated by the allowance from the government. The more the government provides allowance, the more actively the insurance company will implement forest insurance at a low insurance premium. In this situation, the forest farmer will be more likely to purchase the forest insurance, then the scope of forest insurance implementation will expend. Originality/value: There is a complex and dynamic game relationship among all participants in forest insurance market. Based on the tripartite dynamic game model, to make the game relationship between each participant clear is conducive to the implementation of forest insurance market in China.

  9. Nitrate removal in a restored riparian groundwater system: functioning and importance of individual riparian zones

    Directory of Open Access Journals (Sweden)

    S. Peter

    2012-11-01

    Full Text Available For the design and the assessment of river restoration projects, it is important to know to what extent the elimination of reactive nitrogen (N can be improved in the riparian groundwater. We investigated the effectiveness of different riparian zones, characterized by a riparian vegetation succession, for nitrate (NO3 removal from infiltrating river water in a restored and a still channelized section of the river Thur, Switzerland. Functional genes of denitrification (nirS and nosZ were relatively abundant in groundwater from willow bush and mixed forest dominated zones, where oxygen concentrations remained low compared to the main channel and other riparian zones. After flood events, a substantial decline in NO3 concentration (> 50% was observed in the willow bush zone but not in the other riparian zones closer to the river. In addition, the characteristic enrichment of 15N and 18O in the residual NO3 pool (by up to 22‰ for δ15N and up to 12‰ for δ18O provides qualitative evidence that the willow bush and forest zones were sites of active denitrification and, to a lesser extent, NO3 removal by plant uptake. Particularly in the willow bush zone during a period of water table elevation after a flooding event, substantial input of organic carbon into the groundwater occurred, thereby fostering post-flood denitrification activity that reduced NO3 concentration with a rate of ~21 μmol N l−1 d−1. Nitrogen removal in the forest zone was not sensitive to flood pulses, and overall NO3 removal rates were lower (~6 μmol l−1 d−1. Hence, discharge-modulated vegetation–soil–groundwater coupling was found to be a key driver for riparian NO3 removal. We estimated that

  10. Piecing together the fragments: Elucidating edge effects on forest carbon dynamics

    Science.gov (United States)

    Hutyra, L.; Smith, I. A.; Reinmann, A.; Marrs, J.; Thompson, J.

    2017-12-01

    Forest fragmentation is pervasive throughout the world's forests, impacting growing conditions and carbon dynamics through edge effects that produce gradients in microclimate, biogeochemistry, and stand structure. Despite the majority of the world's forests being biome, but current forest carbon accounting methods and ecosystem models largely do not include edge effects, highlighting an important gap in our understanding of the terrestrial carbon cycle. Characterizing the role of forest fragmentation in regional and global biogeochemical cycles necessitates advancing our understanding of how shifts in microenvironment at the forest edge interact with local prevailing drivers of global change and limitations to microbial activity and forest growth. This study synthesizes the literature related to edge effects and the carbon cycle, considering how fragmentation affects the growing conditions of the world's remaining forests based on risks and opportunities for forests near the edge.

  11. Learning from the past: Trends and dynamics in livelihoods of Bolivian forest communities

    NARCIS (Netherlands)

    Zenteno, M.; Jong, de W.; Boot, R.; Zuidema, P.A.

    2014-01-01

    We use social ecological systems theory (SES) to analyse change in forest communities in the northern Bolivian Amazon. SES characterizes interdependent dynamics of social and ecological systems and we hypothesized it to be a useful frame to grasp dynamics of forest communities affected by changes in

  12. Chemical and microbiological properties of an eutrophic Oxisol under riparian forest buffer reforestation and pasture. Propriedades químicas e microbiológicas de um Latossolo Vermelho eutrófico sob reflorestamento de mata ciliar e pastagem.

    Directory of Open Access Journals (Sweden)

    Fabiana Marise PULITANO

    2013-06-01

    Full Text Available Regardless of their ecological importance, riparian forest strips are frequently suppressed to allow greater expansion of arable and urban areas. Agroforestry might be an effective alternative to recompose riparian forests. Soil chemical and microbial properties are important environmental indicators to evaluate the reclamation process. This study tested the hypothesis that, in the course of time, reforestation by means of agroforestry improved soil microbial and chemical properties in a riparian forest buffer. Soil samples were collected from three layers (0.0-2.5; 2.5-7.5; 7.5-20 cm in two sectors of a reforested riparian buffer strip in Cananéia Farm, São Paulo state, Brazil, one 18 years old and other 28 years old, and in an adjacent pasture area. The samples were assessed for pHH2O, available P and K, exchangeable, Ca, Mg and Al, H+Al, sum of bases (SB, pH 7.0 CEC, percent base saturation (V, soil organic matter (SOM and light organic matter (LOM. Microbial biomass carbon (MBC and nitrogen (MBN were analyzed only in the first layer. The pattern for Ca, Mg, SB and V (all layers was 28-year-old sector = 18-year-old-sector > pasture. The SOM at 0.0-2.5 cm was higher in the 28-year-old sector. The LOM pattern was 28-year-old sector > 18-year-old sector > pasture. MBC did not differ among areas. MBN was significantly higher comparing the 28-year-old sector and the pasture area. The results probably reflected the higher litterfall and the N-richer organic matter in the reforested sectors. Reforestation by means of agroforestry improved soil quality, contributing to the ecosystem sustainability. Independentemente de sua importância ecológica, matas ciliares são frequentemente suprimidas e ocupadas por lavouras e cidades. Agroflorestas podem ser eficazes para a recomposição dessas áreas. Propriedades químicas e microbiológicas do solo são importantes indicadores ambientais para avaliar o processo de recomposição. Este estudo testou a

  13. Edaphic, salinity, and stand structural trends in chronosequences of native and non-native dominated riparian forests along the Colorado River, USA

    Science.gov (United States)

    Merritt, David M.; Shafroth, Patrick B.

    2012-01-01

    Tamarix spp. are introduced shrubs that have become among the most abundant woody plants growing along western North American rivers. We sought to empirically test the long-held belief that Tamarix actively displaces native species through elevating soil salinity via salt exudation. We measured chemical and physical attributes of soils (e.g., salinity, major cations and anions, texture), litter cover and depth, and stand structure along chronosequences dominated by Tamarix and those dominated by native riparian species (Populus or Salix) along the upper and lower Colorado River in Colorado and Arizona/California, USA. We tested four hypotheses: (1) the rate of salt accumulation in soils is faster in Tamarix-dominated stands than stands dominated by native species, (2) the concentration of salts in the soil is higher in mature stands dominated by Tamarix compared to native stands, (3) soil salinity is a function of Tamarix abundance, and (4) available nutrients are more concentrated in native-dominated stands compared to Tamarix-dominated stands. We found that salt concentration increases at a faster rate in Tamarix-dominated stands along the relatively free-flowing upper Colorado but not along the heavily-regulated lower Colorado. Concentrations of ions that are known to be preferentially exuded by Tamarix (e.g., B, Na, and Cl) were higher in Tamarix stands than in native stands. Soil salt concentrations in older Tamarix stands along the upper Colorado were sufficiently high to inhibit germination, establishment, or growth of some native species. On the lower Colorado, salinity was very high in all stands and is likely due to factors associated with floodplain development and the hydrologic effects of river regulation, such as reduced overbank flooding, evaporation of shallow ground water, higher salt concentrations in surface and ground water due to agricultural practices, and higher salt concentrations in fine-textured sediments derived from naturally saline

  14. Determining effective riparian buffer width for nonnative plant exclusion and habitat enhancement

    Science.gov (United States)

    Gavin Ferris; Vincent D' Amico; Christopher K. Williams

    2012-01-01

    Nonnative plants threaten native biodiversity in landscapes where habitats are fragmented. Unfortunately, in developed areas, much of the remaining forested habitat occurs in fragmented riparian corridors. Because forested corridors of sufficient width may allow forest interior specializing native species to retain competitive advantage over edge specialist and...

  15. Riparian Sediment Delivery Ratio: Stiff Diagrams and Artifical Neural Networks

    Science.gov (United States)

    Various methods are used to estimate sediment transport through riparian buffers and grass jilters with the sediment delivery ratio having been the most widely applied. The U.S. Forest Service developed a sediment delivery ratio using the stiff diagram and a logistic curve to int...

  16. Influence of microtopography on soil chemistry and understory riparian vegetation

    Science.gov (United States)

    Irene M. Unger; Rose-Marie Muzika

    2008-01-01

    The success of riparian forest restoration efforts depends in part on an understanding of the relationship between soil characteristics and vegetation patterns and how these change with site conditions. To examine these relationships for floodplains in northern Missouri, we chose three unchannelized streams as study areas. A sampling grid was established at two plots...

  17. Assessing the extent and diversity of riparian ecosystems in Sonora, Mexico

    Science.gov (United States)

    Scott, M.L.; Nagler, P.L.; Glenn, E.P.; Valdes-Casillas, C.; Erker, J.A.; Reynolds, E.W.; Shafroth, P.B.; Gomez-Limon, E.; Jones, C.L.

    2009-01-01

    Conservation of forested riparian ecosystems is of international concern. Relatively little is known of the structure, composition, diversity, and extent of riparian ecosystems in Mexico. We used high- and low-resolution satellite imagery from 2000 to 2006, and ground-based sampling in 2006, to assess the spatial pattern, extent, and woody plant composition of riparian forests across a range of spatial scales for the state of Sonora, Mexico. For all 3rd and higher order streams, river bottomlands with riparian forests occupied a total area of 2,301 km2. Where forested bottomlands remained, on average, 34% of the area had been converted to agriculture while 39% remained forested. We estimated that the total area of riparian forest along the principal streams was 897 km2. Including fencerow trees, the total forested riparian area was 944 km2, or 0.5% of the total land area of Sonora. Ground-based sampling of woody riparian vegetation consisted of 92, 50 m radius circular plots. About 79 woody plant species were noted. The most important tree species, based on cover and frequency, were willow species Salix spp. (primarily S. goodingii and S. bonplandiana), mesquite species Prosopis spp. (primarily P. velutina), and Fremont cottonwood Populus fremontii. Woody riparian taxa at the reach scale showed a trend of increasing diversity from north to south within Sonora. Species richness was greatest in the willow-bald cypress Taxodium distichum var. mexicanum-Mexican cottonwood P. mexicana subsp. dimorphia ecosystem. The non-native tamarisk Tamarix spp. was rare, occurring at just three study reaches. Relatively natural stream flow patterns and fluvial disturbance regimes likely limit its establishment and spread. ?? 2008 Springer Science + Business Media BV.

  18. Benefit sharing and community participation dynamics in forest management

    DEFF Research Database (Denmark)

    Antony, Bindu; Treue, Thorsten; Salim, Shyam S.

    2014-01-01

    , in Chitwan district of Nepal. The results revealed that availabilty of the benefits do not have direct relation with neither paricipation in activities nor in decision making. Though motivation is a prerequisite to activate participation of people in any activity, other methods of persuasion is also vital...... to continue its pace. Whereas, to influence decision making process, other individual characteristics including nature, leadership quality, experience, knowledge etc. may have great control and can determine the participation dynamics which needs to be studied further....... management. However, it is quite difficult to address the interests of all users and to ensure the participation of all stakeholders in the decentralised forest management process. Moreover, it is evident that people need motivation to participate in any activities. Therefore the present study is focused...

  19. Simulation of the biomass dynamics of Masson pine forest under different management

    Institute of Scientific and Technical Information of China (English)

    ZHANG Gui-lian; WANG Kai-yun; LIU Xin-wei; PENG Shao-lin

    2006-01-01

    TREE submodel affiliated with TREEDYN was used to simulate biomass dynamics of Masson pine (Pinus massoniana) forest under different managements (including thinning, clear cutting, combining thinning with clear cutting). The purpose was to represent biomass dynamics involved in its development, which can provide scientific arguments for management of Masson pine forest. The results showed the scenario that 10% or 20% of biomass of the previous year was thinned every five years from 15 to 40 years made total biomass of pine forest increase slowly and it took more time to reach a mature community; If clear cutting and thinning were combined, the case C (clear cutting at 20 years of forest age, thinning 50% of remaining biomass at 30 years of forest age, and thinning 50% of remaining biomass again at 40 years of forest age) was the best scenario which can accelerate speed of development of Masson pine forest and gained better economic values.

  20. Where are the forests in the United States "not disturbed" over a quarter century?

    Science.gov (United States)

    Huang, C.; Zhao, F. A.; Goward, S. N.; Schleeweis, K.; Michaelis, A.; Masek, J. G.; Dungan, J. L.; Cohen, W. B.; Moisen, G.; Rishmawi, K.

    2015-12-01

    Forests provide many important ecosystem services. Logging, fire, and other disturbances can disrupt or even diminish the provision of these services. Although many map products and inventory data can be used to estimate the total forested area in the United States, it is not clear how much of the country's forest remained undisturbed in recent decades. Through the North American Forest Dynamics (NAFD) study, we have mapped both disturbed and undisturbed forests over the conterminous United States (CONUS) using sub-annual time series of Landsat observations. The results revealed that 33.6% of the land area of CONUS had forest cover during some or all of the years between 1986 and 2010. About two thirds of the nation's forests remained undisturbed during the 25-year period. Most of these undisturbed forests were distributed in western and northern parts of the eastern US. The percentage of undisturbed forest in the southeastern states were lower, about 50% or less. In these states, much of the undisturbed forest was distributed along riparian zones or in protected areas, including national parks and national forests. In the northeastern and western US, riparian zones did not have a significantly higher proportion of undisturbed forests than non-riparian areas. While most protected areas had a high percentage of undisturbed forests, some of them had lower percentages than the average values of their surrounding regions. Topography may also have played a role in keeping forests "undisturbed". Many ecoregions in the western and northern US had a substantially higher percentage of undisturbed forests at high elevations than at low elevations.

  1. Identifying forest patterns from space to explore dynamics across the circumpolar boreal

    Science.gov (United States)

    Montesano, P. M.; Neigh, C. S. R.; Feng, M.; Channan, S.; Sexton, J. O.; Wagner, W.; Wooten, M.; Poulter, B.; Wang, L.

    2017-12-01

    A variety of forest patterns are the result of interactions between broad-scale climate and local-scale site factors and history across the northernmost portion of the circumpolar boreal. Patterns of forest extent, height, and cover help describe forest structure transitions that influence future and reflect past dynamics. Coarse spaceborne observations lack structural detail at forest transitions, which inhibits understanding of these dynamics. We highlight: (1) the use of sub-meter spaceborne stereogrammetry for deriving structure estimates in boreal forests; (2) its potential to complement other spaceborne estimates of forest structure at critical scales; and (3) the potential of these sub-meter and other Landsat-derived structure estimates for improving understanding of broad-scale boreal dynamics such as carbon flux and albedo, capturing the spatial variability of the boreal-tundra biome boundary, and assessing its potential for change.

  2. Complex forest dynamics indicate potential for slowing carbon accumulation in the southeastern United States.

    Science.gov (United States)

    Coulston, John W; Wear, David N; Vose, James M

    2015-01-23

    Over the past century forest regrowth in Europe and North America expanded forest carbon (C) sinks and offset C emissions but future C accumulation is uncertain. Policy makers need insights into forest C dynamics as they anticipate emissions futures and goals. We used land use and forest inventory data to estimate how forest C dynamics have changed in the southeastern United States and attribute changes to land use, management, and disturbance causes. From 2007-2012, forests yielded a net sink of C because of net land use change (+6.48 Tg C yr(-1)) and net biomass accumulation (+75.4 Tg C yr(-1)). Forests disturbed by weather, insect/disease, and fire show dampened yet positive forest C changes (+1.56, +1.4, +5.48 Tg C yr(-1), respectively). Forest cutting caused net decreases in C (-76.7 Tg C yr(-1)) but was offset by forest growth (+143.77 Tg C yr(-1)). Forest growth rates depend on age or stage of development and projected C stock changes indicate a gradual slowing of carbon accumulation with anticipated forest aging (a reduction of 9.5% over the next five years). Additionally, small shifts in land use transitions consistent with economic futures resulted in a 40.6% decrease in C accumulation.

  3. Occupancy dynamics in a tropical bird community: unexpectedly high forest use by birds classified as non-forest species

    Science.gov (United States)

    Ruiz-Gutierrez, Viviana; Zipkin, Elise F.; Dhondt, Andre A.

    2010-01-01

    1. Worldwide loss of biodiversity necessitates a clear understanding of the factors driving population declines as well as informed predictions about which species and populations are at greatest risk. The biggest threat to the long-term persistence of populations is the reduction and changes in configuration of their natural habitat. 2. Inconsistencies have been noted in the responses of populations to the combined effects of habitat loss and fragmentation. These have been widely attributed to the effects of the matrix habitats in which remnant focal habitats are typically embedded. 3. We quantified the potential effects of the inter-patch matrix by estimating occupancy and colonization of forest and surrounding non-forest matrix (NF). We estimated species-specific parameters using a dynamic, multi-species hierarchical model on a bird community in southwestern Costa Rica. 4. Overall, we found higher probabilities of occupancy and colonization of forest relative to the NF across bird species, including those previously categorized as open habitat generalists not needing forest to persist. Forest dependency was a poor predictor of occupancy dynamics in our study region, largely predicting occupancy and colonization of only non-forest habitats. 5. Our results indicate that the protection of remnant forest habitats is key for the long-term persistence of all members of the bird community in this fragmented landscape, including species typically associated with open, non-forest habitats. 6.Synthesis and applications. We identified 39 bird species of conservation concern defined by having high estimates of forest occupancy, and low estimates of occupancy and colonization of non-forest. These species survive in forest but are unlikely to venture out into open, non-forested habitats, therefore, they are vulnerable to the effects of habitat loss and fragmentation. Our hierarchical community-level model can be used to estimate species-specific occupancy dynamics for focal

  4. Dynamics of Coarse Woody Debris Characteristics in the Qinling Mountain Forests in China

    Directory of Open Access Journals (Sweden)

    Jie Yuan

    2017-10-01

    Full Text Available Coarse woody debris (CWD is an essential component in defining the structure and function of forest ecosystems. Long-term dynamics of CWD characteristics not only affect the release rates of chemical elements from CWD, but also the species diversity of inhabiting plants, animals, insects, and microorganisms as well as the overall health of ecosystems. However, few quantitative studies have been done on the long-term dynamics of CWD characteristics in forest ecosystems in China. In this study, we conducted nine tree censuses between 1996 and 2016 at the Huoditang Experimental Forest in the Qinling Mountains of China. We quantified forest biomass including CWD and CWD characteristics such as decay states and diameter classes during this period and correlated with stand, site, and climatic variables. The forest biomass was dominated by live tree biomass (88%; followed by CWD mass (6%–10%. Understory biomass contributed only a small portion (1%–4% of the overall biomass. Significant differences in average annual increment of CWD mass were found among forest stands of different species (p < 0.0001. Forest biomass, stand age, forest type, aspect, slope, stand density, annual average temperature, and precipitation were all significantly correlated with CWD mass (p < 0.05, with forest type exhibiting the strongest correlation (r2 = 0.8256. Over time, the annual mass of different CWD characteristics increased linearly from 1996–2016 across all forest types. Our study revealed that forest biomass, including CWD characteristics, varied by forest type. Stand and site characteristics (forest biomass, forest type, aspect, slope and stand density along with temperature and precipitation played a major role in the dynamics of CWD in the studied forest ecosystems.

  5. Processos hidrológicos em diferentes modelos de plantio de restauração de mata ciliar em região de cerrado. Hydrological processes in different riparian forest restoration models in cerrado domain.

    Directory of Open Access Journals (Sweden)

    Karine Baldo de GÊNOVA

    2007-12-01

    Full Text Available A restauração de florestas ciliares temsido recomendada como a melhor estratégiavisando à proteção dos recursos hídricos e àrecuperação da biodiversidade. No entanto, quasenada se conhece sobre o papel hidrológico dasflorestas plantadas e seus efeitos protetores.O presente estudo teve como objetivo analisarcomparativamente alguns modelos de plantio demata ciliar em região de cerrado, para verificar sediferem quanto ao seu papel na interceptação daágua das chuvas e em sua influência na umidadedo solo, com reflexos sobre a função protetora dafloresta. Foram coletados, durante cinco meses,dados pluviométicos no interior de quatro modelosde plantio aos dezessete anos (um plantio mistocom espécies de cerrado e três plantios puros,com Pinus elliottii, Tapirira guianensis eAnadenanthera falcata e em área aberta paracomparação. Para análises de umidade, foramcoletadas amostras compostas da camada superficialdo solo (0 a 20 cm em cada uma das parcelas.Houve variação na porcentagem da água daschuvas interceptada pelas copas entre os diferentesmodelos, com o maior valor no plantio puro deTapirira guianensis (30,8%, espécie latifoliadaperenifólia e com a maior densidade de árvores.No outro extremo, o plantio de Anadenantherafalcata, uma espécie caducifólia de folhas muitopequenas, reteve apenas 12,5% da água daschuvas. A umidade do solo, como era esperado,foi inversamente proporcional à interceptação.Não se observou correlação entre a biomassaflorestal e a interceptação ou umidade do solo.Riparian forest restoration has beenreported as the most efficient strategy to protectwater resources and to recover biodiversity.However, few is known about the hydrologicalfunctioning of the planted forests and theirprotective effect. Some different riparian forestrestoration models were analized 17 years afterplanting, to verify the hypothesis that differentforest structure and composition are correlated todifferent hydrological

  6. Impact of Forest Harvesting and Forest Regeneration on Runoff Dynamics at Watersheds of Central Siberia

    Directory of Open Access Journals (Sweden)

    A. A. Onuchin

    2014-02-01

    Full Text Available In the paper disturbance of Angara river region forests were estimated and peculiarities of forest regeneration after logging and wild fires were analyzed. According to the landscape classification of the regional study, three groups of landscapes differencing on types of forest successions were developed. It was shown that water protective and water regulate functions of the Angara river region forests change under commercial forest harvesting. Comparisons of the inventory and hydrological data detected that hydrological consequences of commercial forest harvesting are dependent on climatic parameters and forest regeneration peculiarities. In the continental climate conditions, when forest regeneration is delayed, snow storms are more active, snow evaporation increases and runoff reduces. In the process of logging sites overgrown with secondary small-leaved forest, snow accumulation increases and runoff increases, exceeding the value of annual runoff at undisturbed watersheds.

  7. Distribution and dynamics of mangrove forests of South Asia..

    Digital Repository Service at National Institute of Oceanography (India)

    Giri, C.; Long, J.; Abbas, S.; ManiMurali, R.; Qamer, F.M.; Pengra, B.; Thau, D.

    Mangrove forests in South Asia occur along the tidal sea edge of Bangladesh, India, Pakistan, and Sri Lanka. These forests provide important ecosystem goods and services to the region's dense coastal populations and support important functions...

  8. Dynamics of forest cover conversion in and around Bwindi ...

    African Journals Online (AJOL)

    Michael Horsfall

    together determine the rates of deforestation in any particular place (Luoga et al., 2005). The conversions have not spared the forests in and around Bwindi impenetrable forest in Southern western Uganda. The protected forest has a unique eco-system with diverse gene reserves with worldwide interest. It is most popular for ...

  9. The dynamics of pine forests in Prebaikalia under anthropogenic impact

    Directory of Open Access Journals (Sweden)

    T. A. Mikhailova

    2017-02-01

    Full Text Available Analyzed and generalized were the results of prolonged (10–25 years monitoring of condition pine Pinus sylvestris L. forests affected by technogenic pollution and high recreation load in the South Prebaikalia. The results show that both factors have similarity in the stress effect on pine tree-stands, as confirmed by alteration in morphometric parameters of tree assimilating phytomass, decrease in photosynthetic pigments level, as well as by disturbance the nutrient elements proportions in the needles. As tree crown defoliation level reaches 65–70 %, the morphometric parameters for shoots and needles are found to decrease the background level by in 1.3–4.5 times. Under technogenic pollution, the needles’ chlorophylls sum was reduced 2.8–3.5 times, level of carotenoides – to 3.9 times maximum in comparison with the background needles while under high recreation load the green pigments content was reduced 1.9–5.7 times, carotenoids content – to 5.5 times. There is a imbalance in quantitative proportions between nutritional elements under any type of stress, N : P : K proportion changes due to increase of nitrogen level and reduction of phosphorus and potassium level. Index of tree-stand vital condition was calculated on the basis of the representative parameters to analyze the long forest dynamics. Significant reduction was shown in the index in the present time and correspondingly the obvious tendency to pine forest decline in the territories polluted by Irkutsk, Shelekhov, and Angarsk-Usolie industrial centers. At the same time near Cheremkhovo and Sayansk-Zima centers there are not heavy changes in the forest’s condition; during long time a middle level of weakening is registered but in the distance 20 km – a low level of weakening. In the territories characterized by a high recreation load, a sharp trend to declining pine tree-stands vital condition was found, and most clearly it is expressed in the towns of Khuzhir (Olkhon

  10. Response of herbaceous plant community diversity and composition to overstorey harvest within riparian management zones in Northern Hardwoods

    Science.gov (United States)

    Eric K. Zenner; Michelle A. Martin; Brian J. Palik; Jerilynn E. Peck; Charles R. Blinn

    2013-01-01

    Partial timber harvest within riparian management zones (RMZs) may permit active management of riparian forests while protecting stream ecosystems, but impacts on herbaceous communities are poorly understood. We compared herbaceous plant community abundance, diversity and composition in RMZs along small streams in northern Minnesota, USA, among four treatments before...

  11. Forests

    Science.gov (United States)

    Louis R. Iverson; Mark W. Schwartz

    1994-01-01

    Originally diminished by development, forests are coming back: forest biomass is accumulating. Forests are repositories for many threatened species. Even with increased standing timber, however, biodiversity is threatened by increased forest fragmentation and by exotic species.

  12. Distribuição espacial de Mesadenella cuspidata (Lindl. Garay (Orchidaceae em uma floresta ribeirinha em Santa Maria, RS, Brasil Spatial distribution of Mesadenella cuspidata (Lindl. Garay (Orchidaceae in a riparian forest, Santa Maria, RS, Brazil

    Directory of Open Access Journals (Sweden)

    Jean Carlos Budke

    2004-03-01

    Full Text Available Mesadenella cuspidata é uma orquídea terrícola encontrada no interior de florestas no Sul do Brasil. Apesar de seu valor ecológico e ornamental, pouco se conhece sobre a biologia desta espécie. Os objetivos deste trabalho foram identificar o padrão de distribuição espacial de M. cuspidata e verificar se há correlação entre o número de indivíduos jovens e adultos em uma floresta ribeirinha. Para o levantamento, foram amostradas 60 parcelas de 16m² cada. Durante agosto e setembro/2001 foram inventariados os indivíduos jovens e adultos das parcelas. Para identificar-se o padrão de distribuição espacial, utilizaram-se o índice de Morisita (MI e a razão de variância/média (R. Foram encontrados 463 indivíduos jovens e 178 adultos. Indivíduos jovens e adultos apresentaram distribuição espacial agrupada, sendo que os adultos (IM = 2,17; R = 4,52 estão mais agrupados que os jovens (IM = 1,82; R = 7,82. O coeficiente de correlação linear encontrado r = 0,61, demonstrou que a densidade de indivíduos adultos está altamente relacionada à densidade de indivíduos jovens.Mesadenella cuspidata (Lindl. Garay is a terrestrial orchid found inside Southern Brazilian forests. In spite of its ecological and ornamental value, little information is aviable on its biology. The aim of this work was the identification of the spatial distribution patterns of M. cuspidata in a riparian forest. We have sampled 60 quadrats of 16m² each. All the young and adult individuals of the quadrats were included. To identify the pattern of spatial distribution, the Morisita Index (MI and the variance/mean Reason (R were used. The linear correlation coefficient was used to verify if there is correlation between populations of the juvenils and adults. From 641 individuals sampled, 463 were juvenils and 178 were adults. Juvenils and adult individuals presented gregarious spatial distribution, but the adults (MI = 2,17; R = 4,52 were more gregarious than the

  13. Gap Dynamics and Structure of Two Old-Growth Beech Forest Remnants in Slovenia

    Science.gov (United States)

    Rugani, Tihomir; Diaci, Jurij; Hladnik, David

    2013-01-01

    Context Due to a long history of intensive forest exploitation, few European beech (Fagus sylvatica L.) old-growth forests have been preserved in Europe. Material and Methods We studied two beech forest reserves in southern Slovenia. We examined the structural characteristics of the two forest reserves based on data from sample plots and complete inventory obtained from four previous forest management plans. To gain a better understanding of disturbance dynamics, we used aerial imagery to study the characteristics of canopy gaps over an 11-year period in the Kopa forest reserve and a 20-year period in the Gorjanci forest reserve. Results The results suggest that these forests are structurally heterogeneous over small spatial scales. Gap size analysis showed that gaps smaller than 500 m2 are the dominant driving force of stand development. The percentage of forest area in canopy gaps ranged from 3.2 to 4.5% in the Kopa forest reserve and from 9.1 to 10.6% in the Gorjanci forest reserve. These forests exhibit relatively high annual rates of coverage by newly established (0.15 and 0.25%) and closed (0.08 and 0.16%) canopy gaps. New gap formation is dependant on senescent trees located throughout the reserve. Conclusion We conclude that these stands are not even-sized, but rather unevenly structured. This is due to the fact that the disturbance regime is characterized by low intensity, small-scale disturbances. PMID:23308115

  14. Forest dynamics in a forest-tundra ecotone, Medicine Bow Mountains, Wyoming

    Science.gov (United States)

    Christopher J. Earle

    1993-01-01

    The alpine timberline in much of western North America is characterized by a structurally complex transition from subalpine forest to alpine tundra, the forest-tundra ecotone. Trees within the ecotone are typically arrayed across the landscape within clumps or "ribbon forests," elongated strips oriented perpendicular to the prevailing winds. This study...

  15. African Savanna-Forest Boundary Dynamics: A 20-Year Study

    Science.gov (United States)

    Cuni-Sanchez, Aida; White, Lee J. T.; Calders, Kim; Jeffery, Kathryn J.; Abernethy, Katharine; Burt, Andrew; Disney, Mathias; Gilpin, Martin; Gomez-Dans, Jose L.; Lewis, Simon L.

    2016-01-01

    Recent studies show widespread encroachment of forest into savannas with important consequences for the global carbon cycle and land-atmosphere interactions. However, little research has focused on in situ measurements of the successional sequence of savanna to forest in Africa. Using long-term inventory plots we quantify changes in vegetation structure, above-ground biomass (AGB) and biodiversity of trees ≥10 cm diameter over 20 years for five vegetation types: savanna; colonising forest (F1), monodominant Okoume forest (F2); young Marantaceae forest (F3); and mixed Marantaceae forest (F4) in Lopé National Park, central Gabon, plus novel 3D terrestrial laser scanning (TLS) measurements to assess forest structure differences. Over 20 years no plot changed to a new stage in the putative succession, but F1 forests strongly moved towards the structure, AGB and diversity of F2 forests. Overall, savanna plots showed no detectable change in structure, AGB or diversity using this method, with zero trees ≥10 cm diameter in 1993 and 2013. F1 and F2 forests increased in AGB, mainly as a result of adding recruited stems (F1) and increased Basal Area (F2), whereas F3 and F4 forests did not change substantially in structure, AGB or diversity. Critically, the stability of the F3 stage implies that this stage may be maintained for long periods. Soil carbon was low, and did not show a successional gradient as for AGB and diversity. TLS vertical plant profiles showed distinctive differences amongst the vegetation types, indicating that this technique can improve ecological understanding. We highlight two points: (i) as forest colonises, changes in biodiversity are much slower than changes in forest structure or AGB; and (ii) all forest types store substantial quantities of carbon. Multi-decadal monitoring is likely to be required to assess the speed of transition between vegetation types. PMID:27336632

  16. Spatiotemporal Change Detection in Forest Cover Dynamics Along Landslide Susceptible Region of Karakoram Highway, Pakistan

    Science.gov (United States)

    Rashid, Barira; Iqbal, Javed

    2018-04-01

    Forest Cover dynamics and its understanding is essential for a country's social, environmental, and political engagements. This research provides a methodical approach for the assessment of forest cover along Karakoram Highway. It has great ecological and economic significance because it's a part of China-Pakistan Economic Corridor. Landsat 4, 5 TM, Landsat 7 ETM and Landsat 8 OLI imagery for the years 1990, 2000, 2010 and 2016 respectively were subjected to supervised classification in ArcMap 10.5 to identify forest change. The study area was categorized into five major land use land cover classes i.e., Forest, vegetation, urban, open land and snow cover. Results from post classification forest cover change maps illustrated notable decrease of almost 26 % forest cover over the time period of 26 years. The accuracy assessment revealed the kappa coefficients 083, 0.78, 0.77 and 0.85, respectively. Major reason for this change is an observed replacement of native forest cover with urban areas (12.5 %) and vegetation (18.6 %) However, there is no significant change in the reserved forests along the study area that contributes only 2.97 % of the total forest cover. The extensive forest degradation and risk prone topography of the region has increased the environmental risk of landslides. Hence, effective policies and forest management is needed to protect not only the environmental and aesthetic benefits of the forest cover but also to manage the disaster risks. Apart from the forest assessment, this research gives an insight of land cover dynamics, along with causes and consequences, thereby showing the forest degradation hotspots.

  17. Comparing soil organic carbon dynamics in plantation and secondary forest in wet tropics in Puerto Rico

    Science.gov (United States)

    LI YIQING; MING XU; ZOU XIAOMING; PEIJUN SHI§; YAOQI ZHANG

    2005-01-01

    We compared the soil carbon dynamics between a pine plantation and a secondary forest, both of which originated from the same farmland abandoned in 1976 with the same cropping history and soil conditions, in the wet tropics in Puerto Rico from July 1996 to June 1997. We found that the secondary forest accumulated the heavy-fraction organic carbon (HF-OC) measured by...

  18. Tropical forest harvesting and taxation: a dynamic model of harvesting behavior under selective extraction systems

    Science.gov (United States)

    Robert F. Conrad; Malcolm Gillis; D. Evan Mercer

    2005-01-01

    A dynamic model of selective harvesting in multi-species,multi-age tropical forests is developed. Forests are predicted to exhibit different optimal harvesting profiles depending on the nature of their joint cost functions and own or cross-species stock effects. The model is applied to the controversy about incentives produced by various taxes. The impacts of specific...

  19. Hurricane impacts on a pair of coastal forested watersheds: implications of selective hurricane damage to forest structure and streamflow dynamics

    Science.gov (United States)

    A.D. Jayakaran; T.M. Williams; H. Ssegane; D.M. Amatya; B. Song; C.C. Trettin

    2014-01-01

    Hurricanes are infrequent but influential disruptors of ecosystem processes in the southeastern Atlantic and Gulf coasts. Every southeastern forested wetland has the potential to be struck by a tropical cyclone. We examined the impact of Hurricane Hugo on two paired coastal South Carolina watersheds in terms of streamflow and vegetation dynamics, both before and after...

  20. From space and from the ground: determining forest dynamics in settlement projects in the Brazilian Amazon

    NARCIS (Netherlands)

    Diniz, F.H.; Kok, K.; Hott, H.C.; Hoogstra-Klein, M.A.; Arts, B.J.M.

    2013-01-01

    Deforestation in the Brazilian Amazon has been partially attributed to the establishment of settlement projects. Acknowledging the difficulties in quantifying the rate and patterns of deforestation, the objective of this paper is to determine forest dynamics (deforestation and reforestation) in

  1. Effects of local land-use on riparian vegetation, water quality, and the functional organization of macroinvertebrate assemblages.

    Science.gov (United States)

    Fierro, Pablo; Bertrán, Carlos; Tapia, Jaime; Hauenstein, Enrique; Peña-Cortés, Fernando; Vergara, Carolina; Cerna, Cindy; Vargas-Chacoff, Luis

    2017-12-31

    Land-use change is a principal factor affecting riparian vegetation and river biodiversity. In Chile, land-use change has drastically intensified over the last decade, with native forests converted to exotic forest plantations and agricultural land. However, the effects thereof on aquatic ecosystems are not well understood. Closing this knowledge gap first requires understanding how human perturbations affect riparian and stream biota. Identified biological indicators could then be applied to determine the health of fluvial ecosystems. Therefore, this study investigated the effects of land-use change on the health of riparian and aquatic ecosystems by assessing riparian vegetation, water quality, benthic macroinvertebrate assemblages, and functional feeding groups. Twenty-one sites in catchment areas with different land-uses (i.e. pristine forests, native forests, exotic forest plantations, and agricultural land) were selected and sampled during the 2010 to 2012 dry seasons. Riparian vegetation quality was highest in pristine forests. Per the modified Macroinvertebrate Family Biotic Index for Chilean species, the best conditions existed in native forests and the worst in agricultural catchments. Water quality and macroinvertebrate assemblages significantly varied across land-use areas, with forest plantations and agricultural land having high nutrient concentrations, conductivity, suspended solids, and apparent color. Macroinvertebrate assemblage diversity was lowest for agricultural and exotic forest plantation catchments, with notable non-insect representation. Collector-gatherers were the most abundant functional feeding group, suggesting importance independent of land-use. Land-use areas showed no significant differences in functional feeding groups. In conclusion, anthropogenic land-use changes were detectable through riparian quality, water quality, and macroinvertebrate assemblages, but not through functional feeding groups. These data, particularly the

  2. Local understanding of forest conservation in land use change dynamics

    DEFF Research Database (Denmark)

    Shaleh, Muhammad Adha; Guth, Miriam Karen; Rahman, Syed Ajijur

    2016-01-01

    Forest (SEPPSF), Malaysia. Nine in-depth interviews were conducted with Orang Asli Jakun living in SEPPSF using open-ended questions. Local communities have positive perspectives toward the forest conservation program, despite massive environmental changes in their living landscape. This study suggests......The success of local forest conservation program depends on a critical appreciation of local communities. Based on this understanding, the present study aims to explore people’s perspective of forest conservation in a context of changes in their living landscape at South East Pahang Peat Swamp...

  3. Comparison of Organic Matter Dynamics in Soil between Japanese Cedar (Cryptomeria japonica) Forest and Adjacent Japanese Red Pine (Pinus densiflora) Forest Established on Flatland

    OpenAIRE

    Terumasa, Takahashi; Akiko, Minami; Yoshito, Asano; Tatsuaki, Kobayashi; Faculty of Horticulture, Chiba Universit; Faculty of Horticulture, Chiba University:(Present)Hashikami town office; Faculty of Horticulture, Chiba University; Faculty of Horticulture, Chiba University

    1999-01-01

    In order to clarify the effects of tree species on organic matter dynamics in soil, we investigated the amount of forest floor material, leaf litter decomposition rate, soil chemical characteristics, soil respiration rate and cellulose decomposition rate in a Japanese cedar forest (cedar plot) and an adjacent Japanese red pine forest (pine plot) established on a flatland. The amount of forest floor material in the cedar plot was 34.5 Mg ha^ which was greater than that in the pine plot. Becaus...

  4. Carbon dynamics in lakes of the boreal forest under a changing climate

    Energy Technology Data Exchange (ETDEWEB)

    Benoy, G.; Wrona, F. [Environment Canada, Saskatoon, SK (Canada). National Water Research Inst.; Cash, K. [Environment Canada, Saskatoon, SK (Canada). Prairie and Northern Wildlife Research Centre; McCauley, E. [Calgary Univ., AB (Canada). Dept. of Biology

    2007-09-15

    This article reviewed factors influencing lake ecosystem carbon dynamics in boreal forest regions and identified research areas needed to accurately forecast the impacts of climate change on carbon pools and flux rates. The review suggested that carbon pools in profundal and littoral sediments across the boreal forest should be identified. Climate change experiments should be conducted to quantify ecosystem carbon dynamics as well as changes in aquatic food web structures. Whole system experiments are also needed to examine the hydrologic and bio-geochemical conditions in which allochthonous carbon is integrated into food webs in potentially drier climates. Results also indicated the need for a watershed-scale assessment of carbon budgets for lakes in transitional zones between boreal forests, prairies, parklands, forests, and tundra. It was concluded that studies are also needed to investigate the integration of lacustrine carbon pools and flux rates on carbon budgets at both the local watershed and boreal forest biome scale. 113 refs., 3 figs.

  5. Evaluation of Forest Dynamics Focusing on Various Minimum Harvesting Ages in Multi-Purpose Forest Management Planning

    Directory of Open Access Journals (Sweden)

    Derya Mumcu Kucuker

    2015-04-01

    Full Text Available Aim of study: Exploring the potential effects of various forest management strategies on the ability of forest ecosystems to sequester carbon and produce water has become of great concern among forest researchers. The main purpose of this study is to evaluate the effects of management strategies with different minimum harvesting ages on the amount and monetary worth of carbon, water and timber values. Area of study: The study was performed in the Yalnızçam planning unit located on the northeastern part of Turkey. Material and Methods: A forest management model with linear programming (LP was developed to determine the effects of various minimum harvesting ages. Twenty-four different management strategies were developed to maximize the economic Net Present Value (NPV of timber, water and carbon values in addition to their absolute quantities over time. Amount and NPV of forest values and ending inventory with different minimum harvesting ages were used as performance indicators to assess and thus understand forest dynamics. Main results: Amount and NPV of timber and carbon generally decreased with extended minimum harvesting ages. However, similar trends were not observed for water production values. The results pointed out that the performance of a management strategy depends highly on the development of a management strategy and the initial forest structure aside from the growth rate Research highlights: Minimum harvesting ages affect forest outputs under the same objectives and constraints. Performance of a management strategy highly depends on initial age class structure in addition to the contents of a management strategy.

  6. Aboveground Biomass and Litterfall Dynamics in Secondary Forest ...

    African Journals Online (AJOL)

    The differences in aboveground biomass, litterfall patterns and the seasonality of litterfall in three secondary forest fields aged 1, 5 and 10 years of age regenerating from degraded abandoned rubber plantation and a mature forest were studied in southern Nigeria. This is with a view to understanding the possibility of ...

  7. Evergreen understory dynamics in Coweeta forest, North Carolina

    Science.gov (United States)

    M.M. Dobbs; Albert J. Parker

    2004-01-01

    A number of studies have elucidated the distributional patterns of various components of Southern Appalachian forests. The evergreen understory here is composed largely of a dominant ericaceous shrub, Rhododendron maximum L., which is believed to be expanding and inhibiting the development of other species with consequent impacts on overall forest...

  8. Modeling population dynamics and woody biomass of Alaska coastal forest

    Science.gov (United States)

    Randy L. Peterson; Jingjing Liang; Tara M. Barrett

    2014-01-01

    Alaska coastal forest, 6.2 million ha in size, has been managed in the past mainly through clearcutting. Declining harvest and dwindling commercial forest resources over the past 2 decades have led to increased interest in management of young-growth stands and utilization of woody biomass for bioenergy. However, existing models to support these new management systems...

  9. Nitrogen alters carbon dynamics during early succession in boreal forest

    Science.gov (United States)

    Steven D. Allison; Tracy B. Gartner; Michelle C. Mack; Krista McGuire; Kathleen. Treseder

    2010-01-01

    Boreal forests are an important source of wood products, and fertilizers could be used to improve forest yields, especially in nutrient poor regions of the boreal zone. With climate change, fire frequencies may increase, resulting in a larger fraction of the boreal landscape present in early successional stages. Since most fertilization studies have focused on mature...

  10. Temperate forest dynamics and carbon storage: A 26-year case ...

    African Journals Online (AJOL)

    Overall, these results suggest that the forest is in a post-disturbance recovery phase, although favourable climatic conditions over the last three decades may also have had an influence on AGB accumulation. Keywords: aboveground biomass, carbon sequestration, forest conservation, long-term monitoring, succession ...

  11. Composição florística de florestas estacionais ribeirinhas no estado de Mato Grosso do Sul, Brasil Floristic composition of seasonal riparian forests in Mato Grosso do Sul state, Brazil

    Directory of Open Access Journals (Sweden)

    Vivian Ribeiro Baptista-Maria

    2009-06-01

    time. The floristic survey resulted in 56 families, 184 genera and 307 species. Of the total number of species, 68% were trees, 17% shrubs, 14% lianas and only 1% palms. The Fabaceae family (Leguminosae, represented by 51 (16.6% species, was the most species-rich. These results increase our knowledge of the Mato Grosso do Sul flora and its geographic distribution, thus emphasizing the need for conservation of these riparian forests and providing subsidies for restoration projects of the degraded areas around the conservation unit and permanent protection areas (APPs of regional rivers.

  12. RGB-NDVI colour composites for visualizing forest change dynamics

    Science.gov (United States)

    Sader, S. A.; Winne, J. C.

    1992-01-01

    The study presents a simple and logical technique to display and quantify forest change using three dates of satellite imagery. The normalized difference vegetation index (NDVI) was computed for each date of imagery to define high and low vegetation biomass. Color composites were generated by combining each date of NDVI with either the red, green, or blue (RGB) image planes in an image display monitor. Harvest and regeneration areas were quantified by applying a modified parallelepiped classification creating an RGB-NDVI image with 27 classes that were grouped into nine major forest change categories. Aerial photographs and stand history maps are compared with the forest changes indicated by the RGB-NDVI image. The utility of the RGB-NDVI technique for supporting forest inventories and updating forest resource information systems are presented and discussed.

  13. Anthropogenic Land-use Change and the Dynamics of Amazon Forest Biomass

    Science.gov (United States)

    Laurance, William F.

    2004-01-01

    This project was focused on assessing the effects of prevailing land uses, such as habitat fragmentation, selective logging, and fire, on biomass and carbon storage in Amazonian forests, and on the dynamics of carbon sequestration in regenerating forests. Ancillary goals included developing GIs models to help predict the future condition of Amazonian forests, and assessing the effects of anthropogenic climate change and ENS0 droughts on intact and fragmented forests. Ground-based studies using networks of permanent plots were linked with remote-sensing data (including Landsat TM and AVHRR) at regional scales, and higher-resolution techniques (IKONOS imagery, videography, LIDAR, aerial photographs) at landscape and local scales. The project s specific goals were quite eclectic and included: Determining the effects of habitat fragmentation on forest dynamics, floristic composition, and the various components of above- and below-ground biomass. Assessing historical and physical factors that affect trajectories of forest regeneration and carbon sequestration on abandoned lands. Extrapolating results from local studies of biomass dynamics in fragmented and regenerating forests to landscape and regional scales in Amazonia, using remote sensing and GIS. Testing the hypothesis that intact Amazonian forests are functioning as a significant carbon sink. Examining destructive synergisms between forest fragmentation and fire. Assessing the short-term impacts of selective logging on aboveground biomass. Developing GIS models that integrate current spatial data on forest cover, deforestation, logging, mining, highway and roads, navigable rivers, vulnerability to wild fires, protected areas, and existing and planned infrastructure projects, in an effort to predict the future condition of Brazilian Amazonian forests over the next 20-25 years. Devising predictive spatial models to assess the influence of varied biophysical and anthropogenic predictors on Amazonian deforestation.

  14. Composição da avifauna em duas matas ciliares na bacia do rio Jacaré-Pepira, São Paulo, Brasil Bird community composition of two riparian forests at Jacaré-Pepira river, São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Maria Elisa de Castro Almeida

    1999-01-01

    Full Text Available A quali-quantitative survey was carried out in two riparian forests fragmente (approximately 40 ha each at Jacaré-Pepira river. Our intention was to characterize its bird community conceming richness, abundance and species occurrence in these areas. The qualitative survey showed 130 species at Santa Elisa (Brotas, São Paulo and 151 at Morro Chato (Dourado, São Paulo, whereas the quantitative survey revealed the presence of 69 and 75 species at Santa Elisa and Morro Chato, respectively. The small size and the isolation might be responsible for the low number of species found. Observing the abundance index values (IPA we realize that there are a few number of species with a high IPA on the one hand, while on the other there is a large number of species with intermediate and low IPA rates. A high detection coefficient (vocalization, low predatoiy rates and competition might have contributed for the higher abundance values found among these species. Furthermore, we have also registered species which are abundant in a fragment, but absent in the other, which might be explained by initial exclusion or local extinction. In spite of the riparian forests being protected by law, its clearing process has not stopped yet. Therefore, the study of this bird community is of uppermost impoitance for the elaboration of both conservation and management projects regarding these areas.

  15. Linking Above- and Belowground Dynamics in Tropical Urban Forests

    Science.gov (United States)

    Atkinson, E. E.; Marin-Spiotta, E.

    2013-12-01

    Secondary forests that emerge after a long history of agriculture can have altered plant community composition and relative abundances of different species. These forests can look and behave differently compared to pre-agricultural forests due changes in primary productivity, resource allocation, and phenology, which can significantly affect processes such as carbon accumulation and nutrient availability. Our research explores how alternative successional trajectories following intensive agricultural use affect linkages among the establishment of novel plant communities, soil nutrient availability and turnover, and soil microbial community composition and function. We hypothesize that different plant species composition due to differing land use legacies and successional trajectories would drive changes in soil microbial community structure and function, affecting soil C and N chemistry and turnover. We conducted this research in the subtropical dry forest life zone of St. Croix, U.S. Virgin Islands where island-wide abandonment of sugarcane resulted in a mosaic of sites in different stages of forest succession. We identified replicate sites with the following post-sugarcane trajectories: 1) natural forest regeneration, 2) low intensity pasture use, followed by reforestation with timber plantation, which are no longer being managed, 3) high intensity pasture use and recent natural forest regeneration, and 4) high intensity pasture use and current active grazing. During 2011-2013, we sampled soils seasonally (0-10 cm) and measured tree species composition. The successional trajectories showed distinct tree species composition. The first two trajectories yielded 40-year old mixed-species secondary forest, dominated by the dry forest tree species Melicoccus bijugatas, Guapira fragrans, Maniklara zapota, and Sideroxylon foetidissimum. The tree species Melicoccus bijugatas primarily drove differences between the first two trajectories (natural forest regeneration vs

  16. Riparian Habitat - Product of 2 riparian habitat workshops

    Data.gov (United States)

    California Natural Resource Agency — In two riparian habitat workshops held between 2001 and 2002, scientists and managers identified the need for determining the scope of a consistent and acceptable...

  17. Contributions of secondary forest and nitrogen dynamics to terrestrial carbon uptake

    Directory of Open Access Journals (Sweden)

    X. Yang

    2010-10-01

    Full Text Available We use a terrestrial carbon-nitrogen cycle component of the Integrated Science Assessment Model (ISAM to investigate the impacts of nitrogen dynamics on regrowing secondary forests over the 20th century. We further examine what the impacts of nitrogen deposition and land use change history are on terrestrial carbon uptake since preindustrial time. Our results suggest that global total net land use emissions for the 1990s associated with changes in cropland, pastureland, and wood harvest are 1.22 GtC/yr. Without considering the secondary forest regrowth, the estimated net global total land use emissions are 1.58 GtC/yr or about 0.36 GtC/yr higher than if secondary forest regrowth is considered. Results also show that without considering the nitrogen dynamics and deposition, the estimated global total secondary forest sink for the 1990s is 0.90 GtC/yr or about 0.54 GtC/yr higher than estimates that include the impacts of nitrogen dynamics and deposition. Nitrogen deposition alone is responsible for about 0.13 GtC/yr of the total secondary forest sink. While nitrogen is not a limiting nutrient in the intact primary forests in tropical regions, our study suggests that nitrogen becomes a limiting nutrient for regrowing secondary forests of the tropical regions, in particular Latin America and Tropical Africa. This is because land use change activities, especially wood harvest, removes large amounts of nitrogen from the system when slash is burnt or wood is removed for harvest. However, our model results show that carbon uptake is enhanced in the tropical secondary forests of the Indian region. We argue that this may be due to enhanced nitrogen mineralization and increased nitrogen availability following land use change in the Indian tropical forest ecosystems. Results also demonstrate that there is a significant amount of carbon accumulating in the Northern Hemisphere where most land use changes and forest regrowth has occurred in recent decades

  18. Effects of reintroduced beaver (Castor canadensis) on riparian bird community structure along the upper San Pedro River, southeastern Arizona and northern Sonora, Mexico

    Science.gov (United States)

    Johnson, Glenn E.; van Riper, Charles

    2014-01-01

    Chapter 1.—We measured bird abundance and richness along the upper San Pedro River in 2005 and 2006, in order to document how beavers (Castor canadensis) may act as ecosystem engineers after their reintroduction to a desert riparian area in the Southwestern United States. In areas where beavers colonized, we found higher bird abundance and richness of bird groups, such as all breeding birds, insectivorous birds, and riparian specialists, and higher relative abundance of many individual species—including several avian species of conservation concern. Chapter 2.—We conducted bird surveys in riparian areas along the upper San Pedro River in southeastern Arizona (United States) and northern Sonora (Mexico) in order to describe factors influencing bird community dynamics and the distribution and abundance of species, particularly those of conservation concern. These surveys were also used to document the effects of the ecosystem-altering activities of a recently reintroduced beavers (Castor canadensis). Chapter 3.—We reviewed Southwestern Willow Flycatcher (Empidonax traillii extimus) nest records and investigated the potential for future breeding along the upper San Pedro River in southeastern Arizona, where in July 2005 we encountered the southernmost verifiable nest attempt for the species. Continued conservation and management of the area’s riparian vegetation and surface water has potential to contribute additional breeding sites for this endangered Willow Flycatcher subspecies. Given the nest record along the upper San Pedro River and the presence of high-density breeding sites to the north, the native cottonwood-willow forests of the upper San Pedro River could become increasingly important to E. t. extimus recovery, especially considering the anticipated effect of the tamarisk leaf beetle (Diorhabda carinulata) on riparian habitat north of the region.

  19. Dynamics of Industrial Forests in Southeast United States Assessed using Satellite and Field Inventory Data

    Science.gov (United States)

    Huang, C.; Tao, X.; Zhao, F. A.; Schleeweis, K.; Ling, P. Y.; Goward, S. N.; Masek, J. G.; Michaelis, A.

    2015-12-01

    The southeast United States (SE-US) is dominated by tree plantations and other forms of industrial forests that provide vital socio-ecological services to the human society. Most of these forests are managed to maximize economic outcome, and hence are often subject to intensive management practices and have different harvest-regrowth cycles as compared with natural forest ecosystems. Through the North American Forest Dynamics (NAFD) study, we have mapped forest disturbances for the conterminous United States using dense time series Landsat observations. The derived map products revealed that more than 50% of the forests in SE-US were harvested or disturbed by other forms of human or natural disturbance events at least once between 1986 and 2010. These products are being analyzed together with ancillary GIS data sets and field inventory data to identify industrial forests and to quantify their logging intensity, timber output, recovery rate, and the harvest-regrowth cycle. The derived results will be summarized in this presentation, along with discussions of the underlying environmental and management factors that may drive the spatio-temporal dynamics of the industrial forests in SE-US.

  20. Logging impacts on forest structure and seedling dynamics in a Prioria copaifera (Fabaceae) dominated tropical rain forest (Talamanca, Costa Rica).

    Science.gov (United States)

    Valverde-Barrantes, Oscar J; Rocha, Oscar J

    2014-03-01

    The factors that determine the existence of tropical forests dominated by a single species (monodominated forests) have been the subject of debate for a long time. It has been hypothesized that the low frequency of disturbances in monodominated forests and the tolerance to shade of the monodominant species are two important factors explaining the prolonged dominance of a single species. We determined the role of these two factors by examining the effects of logging activities on the floristic composition and seedling dynamics in a Prioria copaifera dominated forest in Southeastern Costa Rica. We determined the floristic composition for trees > or = 2.5cm DBH and the associated recruitment, survival and mortality of tree canopy seedlings in two sites logged two (L-02) and 12 years (L-12) prior to sampling and an unlogged forest (ULF). Our results showed that L-02 stands had lower species richness (25 species) than the L-12 and ULF stands (49 and 46 species, respectively). As expected, we found significant logging effects on the canopy structure of the altered forests, particularly when comparing the L-02 and the ULF stands. Seedling density was higher in ULF (0.96 seedlings/ m2) than in the L-02 and L-12 stands (0.322 and 0.466 seedlings/m2, respectively). However, seedling mortality was higher in the ULF stands (54%) than in the L-02 (26%) and L-12 (15%) stands. P. macroloba in L-02 was the only species with abundant regeneration under P. copaifera in L-02 stand, where it accounted for 35% of the seedlings. Despite the reduction in seedling abundance observed after logging, P. copaifera seems to maintain large seedling populations in these forests, suggesting that this species maintains its dominance after logging disturbances. Our findings challenge the hypothesis that the regeneration of monodominant species is not likely to occur under heavily disturbed canopy conditions.

  1. Logging impacts on forest structure and seedling dynamics in a Prioria copaifera (Fabaceae dominated tropical rain forest (Talamanca, Costa Rica

    Directory of Open Access Journals (Sweden)

    Oscar J. Valverde-Barrantes

    2014-03-01

    Full Text Available The factors that determine the existence of tropical forests dominated by a single species (monodominated forests have been the subject of debate for a long time. It has been hypothesized that the low frequency of disturbances in monodominated forests and the tolerance to shade of the monodominant species are two important factors explaining the prolonged dominance of a single species. We determined the role of these two factors by examining the effects of logging activities on the floristic composition and seedling dynamics in a Prioria copaifera dominated forest in Southeastern Costa Rica. We determined the floristic composition for trees ≥2.5cm DBH and the associated recruitment, survival and mortality of tree canopy seedlings in two sites logged two (L-02 and 12 years (L-12 prior to sampling and an unlogged forest (ULF. Our results showed that L-02 stands had lower species richness (25 species than the L-12 and ULF stands (49 and 46 species, respectively. As expected, we found significant logging effects on the canopy structure of the altered forests, particularly when comparing the L-02 and the ULF stands. Seedling density was higher in ULF (0.96 seedlings/m² than in the L-02and L-12 stands (0.322 and 0.466 seedlings/m², respectively. However, seedling mortality was higher in the ULF stands (54% than in the L-02 (26% and L-12 (15% stands. P. macroloba in L-02 was the only species with abundant regeneration under P. copaifera in L-02 stand, where it accounted for 35% of the seedlings. Despite the reduction in seedling abundance observed after logging, P. copaifera seems to maintain large seedling populations in these forests, suggesting that this species maintains its dominance after logging disturbances. Our findings challenge the hypothesis that the regeneration of monodominant species is not likely to occur under heavily disturbed canopy conditions. Rev. Biol. Trop. 62 (1: 347-357. Epub 2014 March 01.

  2. Nitrogen Deposition Effects on Soil Carbon Dynamics in Temperate Forests

    DEFF Research Database (Denmark)

    Ginzburg Ozeri, Shimon

    Soils contain the largest fraction of terrestrial carbon (C). Understanding the factors regulating the decomposition and storage of soil organic matter (SOM) is essential for predictions of the C sink strength of the terrestrial environment in the light of global change. Elevated long-term nitrog...... implications for modelling the carbon sink-strength of temperate forests under global change.......Soils contain the largest fraction of terrestrial carbon (C). Understanding the factors regulating the decomposition and storage of soil organic matter (SOM) is essential for predictions of the C sink strength of the terrestrial environment in the light of global change. Elevated long-term nitrogen...... (N) deposition into forest ecosystems has been increasing globally and was hypothesized to raise soil organic C (SOC) stocks by increasing forest productivity and by reducing SOM decomposition. Yet, these effects of N deposition on forest SOC stocks are uncertain and largely based on observations...

  3. Analyzing the ecosystem carbon dynamics of four European coniferous forests using a biogeochemistry model

    NARCIS (Netherlands)

    Churkina, G.; Tenhunen, J.; Thornton, P.; Falge, E.; Elbers, J.A.; Erhard, M.; Grünwald, T.; Kowalski, A.; Rannik, Ü.; Sprinz, D.

    2003-01-01

    This paper provides the first steps toward a regional-scale analysis of carbon (C) budgets. We explore the ability of the ecosystem model BIOME-BGC to estimate the daily and annual C dynamics of four European coniferous forests and shifts in these dynamics in response to changing environmental

  4. An individual-based process model to simulate landscape-scale forest ecosystem dynamics

    Science.gov (United States)

    Rupert Seidl; Werner Rammer; Robert M. Scheller; Thomas Spies

    2012-01-01

    Forest ecosystem dynamics emerges from nonlinear interactions between adaptive biotic agents (i.e., individual trees) and their relationship with a spatially and temporally heterogeneous abiotic environment. Understanding and predicting the dynamics resulting from these complex interactions is crucial for the sustainable stewardship of ecosystems, particularly in the...

  5. Riparian Habitat - San Joaquin River

    Data.gov (United States)

    California Natural Resource Agency — The immediate focus of this study is to identify, describe and map the extent and diversity of riparian habitats found along the main stem of the San Joaquin River,...

  6. Evaluating the sensitivity of Eurasian forest biomass to climate change using a dynamic vegetation model

    International Nuclear Information System (INIS)

    Shuman, J K; Shugart, H H

    2009-01-01

    Climate warming could strongly influence the structure and composition of the Eurasian boreal forest. Temperature related changes have occurred, including shifts in treelines and changes in regeneration. Dynamic vegetation models are well suited to the further exploration of the impacts that climate change may have on boreal forests. Using the individual-based gap model FAREAST, forest composition and biomass are simulated at over 2000 sites across Eurasia. Biomass output is compared to detailed forest data from a representative sample of Russian forests and a sensitivity analysis is performed to evaluate the impact that elevated temperatures and modified precipitation will have on forest biomass and composition in Eurasia. Correlations between model and forest inventory biomass are strong for several boreal tree species. A significant relationship is shown between altered precipitation and biomass. This analysis showed that a modest increase in temperature of 2 deg. C across 200 years had no significant effect on biomass; however further exploration with increased warming reflective of values measured within Siberia, or at an increased rate, are warranted. Overall, FAREAST accurately simulates forest biomass and composition at sites throughout a large geographic area with widely varying climatic conditions and produces reasonable biomass responses to simulated climatic shifts. These results indicate that this model is robust and useful in making predictions regarding the effect of future climate change on boreal forest structure across Eurasia.

  7. Hurricane impacts on a pair of coastal forested watersheds: implications of selective hurricane damage to forest structure and streamflow dynamics

    OpenAIRE

    A. D. Jayakaran; T. M. Williams; H. Ssegane; D. M. Amatya; B. Song; C. C. Trettin

    2014-01-01

    Hurricanes are infrequent but influential disruptors of ecosystem processes in the southeastern Atlantic and Gulf coasts. Every southeastern forested wetland has the potential to be struck by a tropical cyclone. We examined the impact of Hurricane Hugo on two paired coastal watersheds in South Carolina in terms of stream flow and vegetation dynamics, both before and after the hurricane's passage in 1989. The study objectives were to quantify the magnitude and timing of changes including a rev...

  8. The radiocesium dynamics in the Fukushima forests at the late stage after deposition

    Science.gov (United States)

    Yoschenko, Vasyl; Takase, Tsugiko; Nanba, Kenji; Konoplev, Alexei; Onda, Yuichi

    2017-04-01

    Forests cover about 2/3 of the territory of Areas 2 and 3 in the Fukushima prefecture. This territory was heavily contaminated with radiocesium released from the Fukushima Dai-Ichi Nuclear Power Plant in March 2011. The extensive decontamination measures aimed to prepare the return of population have been scheduled and are being implemented at the agricultural and residential lands at this territory. However, these measures will be not applied in the large scale in the Fukushima forests. The current radiocesium levels in wood at this territory exceed the Japanese standards for wood; thus, after return of population, the Fukushima forests may remain excluded from the economical use. Understanding of the further dynamics of radiocesium in the forest ecosystems is necessary for elaboration of the strategy concerning the radioactive contaminated Fukushima forests. In March 2011 radiocesium was intercepted by the tree canopies and then, at the early stage after the accident, was effectively transported to the soil surface with precipitation and litterfall, and partly translocated to wood forming the current levels. The general trend was the decrease of the radiocesium inventory in the aboveground forest biomass. After redistribution in the root-inhabited soil layer radiocesium became available for uptake into the trees through the roots. From the Chernobyl experience, the further levels of radiocesium in the forest ecosystem compartments at the late stage may increase or decrease depending on the intensities of the root uptake and removal fluxes. In the Fukushima forests, the stage of the root uptake has begun recently, and the parameters of the root uptake have not been studied well for the varieties of species, forest types and soil conditions. Our study is aimed to monitoring and modelling of the radiocesium redistribution in the Fukushima forests after the removal of its initial deposition from the tree canopies. The study has been performed since May 2014 at

  9. NACP North American Forest Dynamics Project: Forest Disturbance and Regrowth Data

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set provides the results of time-series analyses of Landsat imagery for 55 selected forested sites across the conterminous U.S.A. The output is a...

  10. Riparian planning in Yogyakarta City

    Science.gov (United States)

    Rachmawati, R.; Prakoso, E.; Sadali, M. I.; Yusuf, M. G.

    2018-04-01

    Riparian is a potential for slums in urban areas. The city of Yogyakarta is passed by three rivers namely Code, Gajahwong, and Winongo, crossing the city. Riparian in the three rivers are potential for slum if the area is not well managed. This paper is based on the survey results of the structured interview with the people living in the riparian area in Yogyakarta City. They were 75 respondents from the three riparian. The result shows that several reasons why people prefer to remain living in the area are limited spaces and high land price in the city as well as inherited from their parents. The facts that there are still several problems related to the condition of settlement environment in the riparian, i.e., The condition of densely-populated areas, limited availability of land, and limited public spaces. Efforts that can be done to solve problems related to the riparian planning are anticipating disasters like flood and landslide, paying attention to densely-populated and unwell-planned areas, and handling garbage that has been abandoned into the river. The program expected by those living along both riversides is intended to give priorities on providing some aid for those whose houses are not in good condition, controlling buildings without a permit, and building a dike along the river. Efficiency can be made by making use of the space adequately between the one for settlement and the other one for open-green space for both aesthetic and economic purposes.

  11. The impact of future forest dynamics on climate: interactive effects of changing vegetation and disturbance regimes

    Science.gov (United States)

    Thom, Dominik; Rammer, Werner; Seidl, Rupert

    2018-01-01

    Currently, the temperate forest biome cools the earth’s climate and dampens anthropogenic climate change. However, climate change will substantially alter forest dynamics in the future, affecting the climate regulation function of forests. Increasing natural disturbances can reduce carbon uptake and evaporative cooling, but at the same time increase the albedo of a landscape. Simultaneous changes in vegetation composition can mitigate disturbance impacts, but also influence climate regulation directly (e.g., via albedo changes). As a result of a number of interactive drivers (changes in climate, vegetation, and disturbance) and their simultaneous effects on climate-relevant processes (carbon exchange, albedo, latent heat flux) the future climate regulation function of forests remains highly uncertain. Here we address these complex interactions to assess the effect of future forest dynamics on the climate system. Our specific objectives were (1) to investigate the long-term interactions between changing vegetation composition and disturbance regimes under climate change, (2) to quantify the response of climate regulation to changes in forest dynamics, and (3) to identify the main drivers of the future influence of forests on the climate system. We investigated these issues using the individual-based forest landscape and disturbance model (iLand). Simulations were run over 200 yr for Kalkalpen National Park (Austria), assuming different future climate projections, and incorporating dynamically responding wind and bark beetle disturbances. To consistently assess the net effect on climate the simulated responses of carbon exchange, albedo, and latent heat flux were expressed as contributions to radiative forcing. We found that climate change increased disturbances (+27.7% over 200 yr) and specifically bark beetle activity during the 21st century. However, negative feedbacks from a simultaneously changing tree species composition (+28.0% broadleaved species) decreased

  12. The impact of future forest dynamics on climate: interactive effects of changing vegetation and disturbance regimes.

    Science.gov (United States)

    Thom, Dominik; Rammer, Werner; Seidl, Rupert

    2017-11-01

    Currently, the temperate forest biome cools the earth's climate and dampens anthropogenic climate change. However, climate change will substantially alter forest dynamics in the future, affecting the climate regulation function of forests. Increasing natural disturbances can reduce carbon uptake and evaporative cooling, but at the same time increase the albedo of a landscape. Simultaneous changes in vegetation composition can mitigate disturbance impacts, but also influence climate regulation directly (e.g., via albedo changes). As a result of a number of interactive drivers (changes in climate, vegetation, and disturbance) and their simultaneous effects on climate-relevant processes (carbon exchange, albedo, latent heat flux) the future climate regulation function of forests remains highly uncertain. Here we address these complex interactions to assess the effect of future forest dynamics on the climate system. Our specific objectives were (1) to investigate the long-term interactions between changing vegetation composition and disturbance regimes under climate change, (2) to quantify the response of climate regulation to changes in forest dynamics, and (3) to identify the main drivers of the future influence of forests on the climate system. We investigated these issues using the individual-based forest landscape and disturbance model (iLand). Simulations were run over 200 yr for Kalkalpen National Park (Austria), assuming different future climate projections, and incorporating dynamically responding wind and bark beetle disturbances. To consistently assess the net effect on climate the simulated responses of carbon exchange, albedo, and latent heat flux were expressed as contributions to radiative forcing. We found that climate change increased disturbances (+27.7% over 200 yr) and specifically bark beetle activity during the 21st century. However, negative feedbacks from a simultaneously changing tree species composition (+28.0% broadleaved species) decreased

  13. DEVELOPMENT OF AN INDEX OF ALIEN SPECIES INVASIVENESS: AN AID TO ASSESSING RIPARIAN VEGETATION CONDITION

    Science.gov (United States)

    Many riparian areas are invaded by alien plant species that negatively affect native species composition, community dynamics and ecosystem properties. We sampled vegetation along reaches of 31 low order streams in eastern Oregon, and characterized species assemblages at patch an...

  14. Model of plutonium dynamics in a deciduous forest ecosystem

    International Nuclear Information System (INIS)

    Garten, C.T. Jr.; Gardner, R.H.; Dahlman, R.C.

    1980-01-01

    A linear compartment model with donor-controlled flows between compartments was designed to describe and simulate the behavior of plutonium ( 239 240 Pu) in a contaminated forest ecosystem at Oak Ridge, TN. At steady states predicted by the model, less than 0.25% of the plutonium in the ecosystem resides in biota. Soil is the major repository of plutonium in the forest, and exchanges of plutonium between soil and litter or soil and tree roots were dominant transfers affecting the ecosystem distribution of plutonium. Variation in predicted steady-state amounts of plutonium in the forest, given variability in the model parameters, indicates that our ability to develop models of plutonium transport in ecosystems should improve with greater precision in data from natural environments and a better understanding of sources of variation in plutonium data

  15. Patterns, drivers and implications of dissolved oxygen dynamics in tropical mangrove forests

    Science.gov (United States)

    Mattone, Carlo; Sheaves, Marcus

    2017-10-01

    Estuarine mangrove forests regulate and facilitate many ecological processes, and provide nursery ground for many commercially important species. However, mangroves grow in sediments with high carbon loading and high respiration rates which can potentially influencing the dissolved oxygen (DO) dynamics of tidal water flowing into mangrove forests, as bacteria strip DO from the incoming water to carry out metabolic functions. In turn this is likely to influence the way nekton and other aquatic organisms utilize mangrove forests. Despite these possibilities, previous work has focused on looking at DO dynamics within mangrove creeks, with little research focusing on understanding DO dynamics within the mangrove forests themselves during tidal inundation or of DO levels of pools within the forest remaining once the tide has ebbed. The present study investigates the pattern in DO at various distances within an estuarine Rhizophora stylosa forest in tropical north Queensland. DO levels were recorded at 5 min interval over 2 days and multiple tidal cycles, data were collected between 2013 and 2014 for a total of 32 tidal cycles encompassing multiples seasons and tidal amplitudes. There were substantial fluctuations in DO, often varying from normoxic to hypoxic within the same tidal cycle. A range of factors influenced DO dynamics, in particular: tidal height, amount of sunlight, tidal phase, and distance from the outer edge of the mangrove forest. In fact, spring tides tend to have high DO saturation, particularly during the flooding phase, however as the tide starts ebbing, DO depletes rapidly especially in areas further inside the forest. Moreover during tidal disconnection the remnant pools within the forest quickly became anoxic. These variations in DO suggest that the use of mangrove forests by animals is likely to be constrained by their ability to withstand low DO levels, and provides a plausible explanation for the apparent paucity of benthic organism observed

  16. Long-term decrease in satellite vegetation indices in response to environmental variables in an iconic desert riparian ecosystem: the Upper San Pedro, Arizona, United States

    Science.gov (United States)

    Nguyen, Uyen; Glenn, Edward P.; Nagler, Pamela L.; Scott, Russell L.

    2015-01-01

    The Upper San Pedro River is one of the few remaining undammed rivers that maintain a vibrant riparian ecosystem in the southwest United States. However, its riparian forest is threatened by diminishing groundwater and surface water inputs, due to either changes in watershed characteristics such as changes in riparian and upland vegetation, or human activities such as regional groundwater pumping. We used satellite vegetation indices to quantify the green leaf density of the groundwater-dependent riparian forest from 1984 to 2012. The river was divided into a southern, upstream (mainly perennial flow) reach and a northern, downstream (mainly intermittent and ephemeral flow) reach. Pre-monsoon (June) Landsat normalized difference vegetation index (NDVI) values showed a 20% drop for the northern reach (P  0·05). NDVI and enhanced vegetation index values were positively correlated (P deterioration of the riparian forest in the northern reach.

  17. Long-term fragmentation effects on the distribution and dynamics of canopy gaps in a tropical montane forest

    Science.gov (United States)

    Nicholas R. Vaughn; Gregory P. Asner; Christian P. Giardina

    2015-01-01

    Fragmentation alters forest canopy structure through various mechanisms, which in turn drive subsequent changes to biogeochemical processes and biological diversity. Using repeated airborne LiDAR (Light Detection and Ranging) mappings, we investigated the size distribution and dynamics of forest canopy gaps across a topical montane forest landscape in Hawaii naturally...

  18. Simulating boreal forest carbon dynamics after stand-replacing fire disturbance : Insights from a global process-based vegetation model

    NARCIS (Netherlands)

    Yue, Chao; Ciais, P.; Luyssaert, S.; Cadule, Patricia; Harden, J. L.; Randerson, J.; Bellassen, V.; Wang, T.; Piao, S.L.; Poulter, B.; Viovy, N.

    2013-01-01

    Stand-replacing fires are the dominant fire type in North American boreal forests. They leave a historical legacy of a mosaic landscape of different aged forest cohorts. This forest age dynamics must be included in vegetation models to accurately quantify the role of fire in the historical and

  19. Evaluating the impacts of slope aspect on forest dynamic succession in Northwest China based on FAREAST model

    Science.gov (United States)

    Hu, Shanshan; Ma, Jianyong; Shugart, Herman H.; Yan, Xiaodong

    2018-03-01

    Mountain forests provide the main water resources and lumber for Northwest China. The understanding of the differences in forests growing among individual slope aspects in mountainous regions is of great significance to the wise management and planning of these natural systems. The aim of this study was to investigate the impacts of slope aspect on forest dynamic succession in Northwest China by using the dynamic forest succession model (FAREAST). First, the simulated forest composition and vertical forest zonation produced by the model were compared against recorded data in three sub-regions of the Altai Mountains. The FAREAST model accurately reproduced the vertical zonation, forest composition, growth curves of the dominant species (Larix sibirica), and forest biomass in the Altai Mountains. Transitions along the forest zones of the Altai Mountains averaged about a 400 m difference between the northern and southern sites. Biomass for forests on north-facing slopes were 11.0, 15.3 and 55.9 t C ha-1 higher than for south-facing slopes in the Northeast, Central and Southeast sub-regions, respectively. Second, our analyses showed that the FAREAST model can be used to predict dynamic forest succession in Northwest China under the influence of slope and aspect. In the Altai Mountains, the north-facing slopes supported the best forest growth, followed by the west- and east-facing slopes. South-facing slopes consistently exhibited the lowest growth, biomass storage and forest diversity.

  20. Primary forest dynamics in lowland dipterocarp forest at Danum Valley, Sabah, Malaysia, and the role of the understorey.

    Science.gov (United States)

    Newbery, D M; Kennedy, D N; Petol, G H; Madani, L; Ridsdale, C E

    1999-11-29

    Changes in species composition in two 4-ha plots of lowland dipterocarp rainforest at Danum, Sabah, were measured over ten years (1986-1996) for trees > or = 10 cm girth at breast height (gbh). Each included a lower-slope to ridge gradient. The period lay between two drought events of moderate intensity but the forest showed no large lasting responses, suggesting that its species were well adapted to this regime. Mortality and recruitment rates were not unusual in global or regional comparisons. The forest continued to aggrade from its relatively (for Sabah) low basal area in 1986 and, together with the very open upper canopy structure and an abundance of lianas, this suggests a forest in a late stage of recovery from a major disturbance, yet one continually affected by smaller recent setbacks. Mortality and recruitment rates were not related to population size in 1986, but across subplots recruitment was positively correlated with the density and basal area of small trees (10-change in mortality with increasing gbh: in the former it increased, in the latter it decreased. Forest processes are centred on this understorey quasi-stratum. The two replicate plots showed a high correspondence in the mortality, recruitment, population changes and growth rates of small trees for the 49 most abundant species in common to both. Overstorey species had higher rgrs than understorey ones, but both showed considerable ranges in mortality and recruitment rates. The supposed trade-off in traits, viz slower rgr, shade tolerance and lower population turnover in the understorey group versus faster potential growth rate, high light responsiveness and high turnover in the overstorey group, was only partly met, as some understorey species were also very dynamic. The forest at Danum, under such a disturbance-recovery regime, can be viewed as having a dynamic equilibrium in functional and structural terms. A second trade-off in shade-tolerance versus drought-tolerance is suggested for

  1. Mercury dynamics and mass balance in a subtropical forest, southwestern China

    Directory of Open Access Journals (Sweden)

    M. Ma

    2016-04-01

    Full Text Available The mid-subtropical forest area in southwest China was affected by anthropogenic mercury (Hg emissions over the past 3 decades. We quantified mercury dynamics on the forest field and measured fluxes and pools of Hg in litterfall, throughfall, stream water and forest soil in an evergreen broadleaved forest field in southwestern China. Total Hg (THg input by the throughfall and litterfall was assessed at 32.2 and 42.9 µg m−2 yr−1, respectively, which was remarkably higher than those observed from other forest fields in the background of North America and Europe. Hg fluxes across the soil–air interface (18.6 mg m−2 yr−1 and runoff and/or stream flow (7.2 µg m−2 yr−1 were regarded as the dominant ways for THg export from the forest field. The forest field hosts an enormous amount of atmospheric Hg, and its reserves is estimated to be 25 341 µg m2. The ratio of output to input Hg fluxes (0.34 is higher compared with other study sites. The higher output / input ratio may represent an important ecological risk for the downstream aquatic ecosystems, even if the forest field could be an effective sink of Hg.

  2. A hierarchical approach for simulating northern forest dynamics

    Science.gov (United States)

    Don C. Bragg; David W. Roberts; Thomas R. Crow

    2004-01-01

    Complexity in ecological systems has challenged forest simulation modelers for years, resulting in a number of approaches with varying degrees of success. Arguments in favor of hierarchical modeling are made, especially for considering a complex environmental issue like widespread eastern hemlock regeneration failure. We present the philosophy and basic framework for...

  3. System identification principles in studies of forest dynamics.

    Science.gov (United States)

    Rolfe A. Leary

    1970-01-01

    Shows how it is possible to obtain governing equation parameter estimates on the basis of observed system states. The approach used represents a constructive alternative to regression techniques for models expressed as differential equations. This approach allows scientists to more completely quantify knowledge of forest development processes, to express theories in...

  4. Dynamics of buckbrush populations under simulated forest restoration alternatives

    Science.gov (United States)

    David W. Huffman; Margaret M. Moore

    2008-01-01

    Plant population models are valuable tools for assessing ecological tradeoffs between forest management approaches. In addition, these models can provide insight on plant life history patterns and processes important for persistence and recovery of populations in changing environments. In this study, we evaluated a set of ecological restoration alternatives for their...

  5. Forest development and carbon dynamics after mountain pine beetle outbreaks

    Science.gov (United States)

    E. Matthew. Hansen

    2014-01-01

    Mountain pine beetles periodically infest pine forests in western North America, killing many or most overstory pine stems. The surviving secondary stand structure, along with recruited seedlings, will form the future canopy. Thus, even-aged pine stands become multiaged and multistoried. The species composition of affected stands will depend on the presence of nonpines...

  6. Dynamics of forest cover conversion in and around Bwindi ...

    African Journals Online (AJOL)

    Land use/cover map for 2010 was reconstructed by analyzing 2001 image, validated and/or reconstructed by ground truthing, use of secondary data and key ... The severe loss of woodlot outside the protected area not only poses a potential threat to the protected forest but also calls for intervention measures if efforts to ...

  7. Disturbance dynamics and ecosystem-based forest management

    Science.gov (United States)

    Kalev Jogiste; W. Keith Moser; Malle. Mandre

    2005-01-01

    Ecosystem-based management is intended to balance ecological, social and economic values of sustainable resource management. The desired future state of forest ecosystem is usually defined through productivity, biodiversity, stability or other terms. However, ecosystem-based management may produce an unbalanced emphasis on different components. Although ecosystem-based...

  8. Population dynamics of Garcinia lucida (Clusiaceae) in Cameroonian Atlantic forests.

    NARCIS (Netherlands)

    Guedje, N.M.; Lejoly, J.; Nkongmeneck, B.A.; Jonkers, W.B.J.

    2003-01-01

    Garcinia lucida Vesque (Clusiaceae) is a highly valued non-timber forest tree. The bark and the seeds are exploited and commercialised for medicinal purposes and palm wine processing in Cameroon, Gabon and Equatorial Guinea. The bark is often removed over almost the entire circumference of the stem,

  9. Principles for Establishing Ecologically Successful Riparian Corridors

    Science.gov (United States)

    Principles for establishing riparian areas. Riparian areas are three‐dimensional ecotones of interaction that include terrestrial and aquatic ecosystems, that extend down into the groundwater, up above the canopy, outward across the floodplain.

  10. Buffer Strips for Riparian Zone Management

    National Research Council Canada - National Science Library

    1991-01-01

    This study provides a review of technical literature concerning the width of riparian buffer strips needed to protect water quality and maintain other important values provided by riparian ecosystem...

  11. Theory, methods and tools for determining environmental flows for riparian vegetation: Riparian vegetation-flow response guilds

    Science.gov (United States)

    Merritt, D.M.; Scott, M.L.; Leroy, Poff N.; Auble, G.T.; Lytle, D.A.

    2010-01-01

    Riparian vegetation composition, structure and abundance are governed to a large degree by river flow regime and flow-mediated fluvial processes. Streamflow regime exerts selective pressures on riparian vegetation, resulting in adaptations (trait syndromes) to specific flow attributes. Widespread modification of flow regimes by humans has resulted in extensive alteration of riparian vegetation communities. Some of the negative effects of altered flow regimes on vegetation may be reversed by restoring components of the natural flow regime. 2. Models have been developed that quantitatively relate components of the flow regime to attributes of riparian vegetation at the individual, population and community levels. Predictive models range from simple statistical relationships, to more complex stochastic matrix population models and dynamic simulation models. Of the dozens of predictive models reviewed here, most treat one or a few species, have many simplifying assumptions such as stable channel form, and do not specify the time-scale of response. In many cases, these models are very effective in developing alternative streamflow management plans for specific river reaches or segments but are not directly transferable to other rivers or other regions. 3. A primary goal in riparian ecology is to develop general frameworks for prediction of vegetation response to changing environmental conditions. The development of riparian vegetation-flow response guilds offers a framework for transferring information from rivers where flow standards have been developed to maintain desirable vegetation attributes, to rivers with little or no existing information. 4. We propose to organise riparian plants into non-phylogenetic groupings of species with shared traits that are related to components of hydrologic regime: life history, reproductive strategy, morphology, adaptations to fluvial disturbance and adaptations to water availability. Plants from any river or region may be grouped

  12. Spatially dynamic forest management to sustain biodiversity and economic returns.

    Science.gov (United States)

    Mönkkönen, Mikko; Juutinen, Artti; Mazziotta, Adriano; Miettinen, Kaisa; Podkopaev, Dmitry; Reunanen, Pasi; Salminen, Hannu; Tikkanen, Olli-Pekka

    2014-02-15

    Production of marketed commodities and protection of biodiversity in natural systems often conflict and thus the continuously expanding human needs for more goods and benefits from global ecosystems urgently calls for strategies to resolve this conflict. In this paper, we addressed what is the potential of a forest landscape to simultaneously produce habitats for species and economic returns, and how the conflict between habitat availability and timber production varies among taxa. Secondly, we aimed at revealing an optimal combination of management regimes that maximizes habitat availability for given levels of economic returns. We used multi-objective optimization tools to analyze data from a boreal forest landscape consisting of about 30,000 forest stands simulated 50 years into future. We included seven alternative management regimes, spanning from the recommended intensive forest management regime to complete set-aside of stands (protection), and ten different taxa representing a wide variety of habitat associations and social values. Our results demonstrate it is possible to achieve large improvements in habitat availability with little loss in economic returns. In general, providing dead-wood associated species with more habitats tended to be more expensive than providing requirements for other species. No management regime alone maximized habitat availability for the species, and systematic use of any single management regime resulted in considerable reductions in economic returns. Compared with an optimal combination of management regimes, a consistent application of the recommended management regime would result in 5% reduction in economic returns and up to 270% reduction in habitat availability. Thus, for all taxa a combination of management regimes was required to achieve the optimum. Refraining from silvicultural thinnings on a proportion of stands should be considered as a cost-effective management in commercial forests to reconcile the conflict

  13. Addressing climate change in the Forest Vegetation Simulator to assess impacts on landscape forest dynamics

    Science.gov (United States)

    Nicholas L. Crookston; Gerald E. Rehfeldt; Gary E. Dixon; Aaron R. Weiskittel

    2010-01-01

    To simulate stand-level impacts of climate change, predictors in the widely used Forest Vegetation Simulator (FVS) were adjusted to account for expected climate effects. This was accomplished by: (1) adding functions that link mortality and regeneration of species to climate variables expressing climatic suitability, (2) constructing a function linking site index to...

  14. Future forest aboveground carbon dynamics in the central United States: the importance of forest demographic processes

    Science.gov (United States)

    Wenchi Jin; Hong S. He; Frank R. Thompson; Wen J. Wang; Jacob S. Fraser; Stephen R. Shifley; Brice B. Hanberry; William D. Dijak

    2017-01-01

    The Central Hardwood Forest (CHF) in the United States is currently a major carbon sink, there are uncertainties in how long the current carbon sink will persist and if the CHF will eventually become a carbon source. We used a multi-model ensemble to investigate aboveground carbon density of the CHF from 2010 to 2300 under current climate. Simulations were done using...

  15. Hurricane impacts on a pair of coastal forested watersheds: implications of selective hurricane damage to forest structure and streamflow dynamics

    Science.gov (United States)

    Jayakaran, A. D.; Williams, T. M.; Ssegane, H.; Amatya, D. M.; Song, B.; Trettin, C. C.

    2014-03-01

    Hurricanes are infrequent but influential disruptors of ecosystem processes in the southeastern Atlantic and Gulf coasts. Every southeastern forested wetland has the potential to be struck by a tropical cyclone. We examined the impact of Hurricane Hugo on two paired coastal South Carolina watersheds in terms of streamflow and vegetation dynamics, both before and after the hurricane's passage in 1989. The study objectives were to quantify the magnitude and timing of changes including a reversal in relative streamflow difference between two paired watersheds, and to examine the selective impacts of a hurricane on the vegetative composition of the forest. We related these impacts to their potential contribution to change watershed hydrology through altered evapotranspiration processes. Using over 30 years of monthly rainfall and streamflow data we showed that there was a significant transformation in the hydrologic character of the two watersheds - a transformation that occurred soon after the hurricane's passage. We linked the change in the rainfall-runoff relationship to a catastrophic change in forest vegetation due to selective hurricane damage. While both watersheds were located in the path of the hurricane, extant forest structure varied between the two watersheds as a function of experimental forest management techniques on the treatment watershed. We showed that the primary damage was to older pines, and to some extent larger hardwood trees. We believe that lowered vegetative water use impacted both watersheds with increased outflows on both watersheds due to loss of trees following hurricane impact. However, one watershed was able to recover to pre hurricane levels of evapotranspiration at a quicker rate due to the greater abundance of pine seedlings and saplings in that watershed.

  16. Carbon Budget and its Dynamics over Northern Eurasia Forest Ecosystems

    Science.gov (United States)

    Shvidenko, Anatoly; Schepaschenko, Dmitry; Kraxner, Florian; Maksyutov, Shamil

    2016-04-01

    The presentation contains an overview of recent findings and results of assessment of carbon cycling of forest ecosystems of Northern Eurasia. From a methodological point of view, there is a clear tendency in understanding a need of a Full and Verified Carbon Account (FCA), i.e. in reliable assessment of uncertainties for all modules and all stages of FCA. FCA is considered as a fuzzy (underspecified) system that supposes a system integration of major methods of carbon cycling study (land-ecosystem approach, LEA; process-based models; eddy covariance; and inverse modelling). Landscape-ecosystem approach 1) serves for accumulation of all relevant knowledge of landscape and ecosystems; 2) for strict systems designing the account, 3) contains all relevant spatially distributed empirical and semi-empirical data and models, and 4) is presented in form of an Integrated Land Information System (ILIS). The ILIS includes a hybrid land cover in a spatially and temporarily explicit way and corresponding attributive databases. The forest mask is provided by utilizing multi-sensor remote sensing data, geographically weighed regression and validation within GEO-wiki platform. By-pixel parametrization of forest cover is based on a special optimization algorithms using all available knowledge and information sources (data of forest inventory and different surveys, observations in situ, official statistics of forest management etc.). Major carbon fluxes within the LEA (NPP, HR, disturbances etc.) are estimated based on fusion of empirical data and aggregations with process-based elements by sets of regionally distributed models. Uncertainties within LEA are assessed for each module and at each step of the account. Within method results of LEA and corresponding uncertainties are harmonized and mutually constrained with independent outputs received by other methods based on the Bayesian approach. The above methodology have been applied to carbon account of Russian forests for 2000

  17. Dynamics of river sediments in forested headwater streams: Plynlimon

    Directory of Open Access Journals (Sweden)

    G. J. L. Leeks

    1997-01-01

    Full Text Available Long term studies of fluvial sediment processes in the Plynlimon catchments have contributed to the assessment and quantification of plantation forestry impacts in British upland catchments, at all stages of the forest cycle. The results from the Plynlimon studies are placed in the context of the observed impacts of particular forest practices and studies of forestry effects on sediment transport elsewhere in the world. The effects associated with drain excavation, ploughing, track construction, ground and channel disruption are outlined for both bedload and, particularly, for suspended load. Finally, recent data on sediment yields from 1995 to 1997 at Plynlimon are reported and discussed in the light of longer-term sediment yield estimates. This paper also provides background information relevant to other sediment process studies which use data from the main Plynlimon sediment monitoring network.

  18. RESPONSE OF RIPARIAN VEGETATION IN AUSTRALIA"S LARGEST RIVER BASIN TO INTER AND INTRA-ANNUAL CLIMATE VARIABILITY AND FLOODING AS QUANTIFIED WITH LANDSAT AND MODIS

    Directory of Open Access Journals (Sweden)

    M. Broich

    2016-06-01

    Full Text Available Australia is a continent subject to high rainfall variability, which has major influences on runoff and vegetation dynamics. However, the resulting spatial-temporal pattern of flooding and its influence on riparian vegetation has not been quantified in a spatially explicit way. Here we focused on the floodplains of the entire Murray-Darling Basin (MDB, an area that covers over 1M km2, as a case study. The MDB is the country’s primary agricultural area with scarce water resources subject to competing demands and impacted by climate change and more recently by the Millennium Drought (1999–2009. Riparian vegetation in the MDB floodplain suffered extensive decline providing a dramatic degradation of riparian vegetation. We quantified the spatial-temporal impact of rainfall, temperature and flooding patters on vegetation dynamics at the subcontinental to local scales and across inter to intra-annual time scales based on three decades of Landsat (25k images, Bureau of Meteorology data and one decade of MODIS data. Vegetation response varied in space and time and with vegetation types, densities and location relative to areas frequently flooded. Vegetation degradation trends were observed over riparian forests and woodlands in areas where flooding regimes have changed to less frequent and smaller inundation extents. Conversely, herbaceous vegetation phenology followed primarily a ‘boom’ and ‘bust’ cycle, related to inter-annual rainfall variability. Spatial patters of vegetation degradation changed along the N-S rainfall gradient but flooding regimes and vegetation degradation patterns also varied at finer scale, highlighting the importance of a spatially explicit, internally consistent analysis and setting the stage for investigating further cross-scale relationships. Results are of interest for land and water management decisions. The approach developed here can be applied to other areas globally such as the Nile river basin and

  19. Modeling the Influence of Dynamic Zoning of Forest Harvesting on Ecological Succession in a Northern Hardwoods Landscape

    Science.gov (United States)

    Patrick A. Zollner; Eric J. Gustafson; Hong S. He; Volker C. Radeloff; David J. Mladenoff

    2005-01-01

    Dynamic zoning (systematic alteration in the spatial and temporal allocation of even-aged forest management practices) has been proposed as a means to change the spatial pattern of timber harvest across a landscape to maximize forest interior habitat while holding timber harvest levels constant. Simulation studies have established that dynamic zoning strategies...

  20. Fifty years dynamics of Russian forests: Impacts on the earth system

    Science.gov (United States)

    Shvidenko, Anatoly; Schepaschenko, Dmitry; Kraxner, Florian

    2015-04-01

    The paper presents a succinct history of Russian forests during the time period of 1960-2010 and reanalysis of their impacts on global carbon and nitrogen cycles. We present dynamics of land cover change (including major categories of forest land) and biometric characteristics of forests (species composition, age structure, growing stock volume etc.) based on reconciling all relevant information (data of forest and land inventories, official forest management statistics, multi-sensor remote sensing products, data of forest pathological monitoring etc.). Completeness and reliability of background information was different during the period of the study. Forest inventory data and official statistics were partially modified based on relevant auxiliary information and used for 1960-2000. The analysis for 2001-2010 was provided with a crucial use of multi-sensor remote sensing data. For this last period a hybrid forest mask was developed at resolution of 230m by integration of 8 remote sensing products and using geographical weighted regression and data of crowdsourcing. During the considered 50 years forested areas of Russia substantially increased by middle of 1990s and slightly declined (at about 5%) after. Indicators needed for assessment of carbon and nitrogen cycles of forest ecosystems were defined for the entire period (aggregated estimates by decades for 1960-2000 and yearly for 2001-2010) based on unified methodology with some peculiarities following from availability of information. Major results were obtained by landscape-ecosystem method that uses as comprehensive as possible empirical and semi-empirical information on ecosystems and landscapes in form of an Integrated Land Information System and complimentary combines pool- and flux-based methods. We discuss and quantify major drivers of forest cover change (socio-economic, environmental and climatic) including forest management (harvest, reforestation and afforestation), impacts of seasonal weather on

  1. Interannual variation of carbon fluxes from three contrasting evergreen forests: the role of forest dynamics and climate.

    Science.gov (United States)

    Sierra, Carlos A; Loescher, Henry W; Harmon, Mark E; Richardson, Andrew D; Hollinger, David Y; Perakis, Steven S

    2009-10-01

    Interannual variation of carbon fluxes can be attributed to a number of biotic and abiotic controls that operate at different spatial and temporal scales. Type and frequency of disturbance, forest dynamics, and climate regimes are important sources of variability. Assessing the variability of carbon fluxes from these specific sources can enhance the interpretation of past and current observations. Being able to separate the variability caused by forest dynamics from that induced by climate will also give us the ability to determine if the current observed carbon fluxes are within an expected range or whether the ecosystem is undergoing unexpected change. Sources of interannual variation in ecosystem carbon fluxes from three evergreen ecosystems, a tropical, a temperate coniferous, and a boreal forest, were explored using the simulation model STANDCARB. We identified key processes that introduced variation in annual fluxes, but their relative importance differed among the ecosystems studied. In the tropical site, intrinsic forest dynamics contributed approximately 30% of the total variation in annual carbon fluxes. In the temperate and boreal sites, where many forest processes occur over longer temporal scales than those at the tropical site, climate controlled more of the variation among annual fluxes. These results suggest that climate-related variability affects the rates of carbon exchange differently among sites. Simulations in which temperature, precipitation, and radiation varied from year to year (based on historical records of climate variation) had less net carbon stores than simulations in which these variables were held constant (based on historical records of monthly average climate), a result caused by the functional relationship between temperature and respiration. This suggests that, under a more variable temperature regime, large respiratory pulses may become more frequent and high enough to cause a reduction in ecosystem carbon stores. Our results

  2. Interannual variation of carbon fluxes from three contrasting evergreen forests: The role of forest dynamics and climate

    Science.gov (United States)

    Sierra, C.A.; Loescher, H.W.; Harmon, M.E.; Richardson, A.D.; Hollinger, D.Y.; Perakis, S.S.

    2009-01-01

    Interannual variation of carbon fluxes can be attributed to a number of biotic and abiotic controls that operate at different spatial and temporal scales. Type and frequency of disturbance, forest dynamics, and climate regimes are important sources of variability. Assessing the variability of carbon fluxes from these specific sources can enhance the interpretation of past and current observations. Being able to separate the variability caused by forest dynamics from that induced by climate will also give us the ability to determine if the current observed carbon fluxes are within an expected range or whether the ecosystem is undergoing unexpected change. Sources of interannual variation in ecosystem carbon fluxes from three evergreen ecosystems, a tropical, a temperate coniferous, and a boreal forest, were explored using the simulation model STANDCARB. We identified key processes that introduced variation in annual fluxes, but their relative importance differed among the ecosystems studied. In the tropical site, intrinsic forest dynamics contributed ?? 30% of the total variation in annual carbon fluxes. In the temperate and boreal sites, where many forest processes occur over longer temporal scales than those at the tropical site, climate controlled more of the variation among annual fluxes. These results suggest that climate-related variability affects the rates of carbon exchange differently among sites. Simulations in which temperature, precipitation, and radiation varied from year to year (based on historical records of climate variation) had less net carbon stores than simulations in which these variables were held constant (based on historical records of monthly average climate), a result caused by the functional relationship between temperature and respiration. This suggests that, under a more variable temperature regime, large respiratory pulses may become more frequent and high enough to cause a reduction in ecosystem carbon stores. Our results also show

  3. Down by the riverside: urban riparian ecology

    Science.gov (United States)

    Peter M. Groffman; Daniel J. Bain; Lawrence E. Band; Kenneth T. Belt; Grace S. Brush; J. Morgan Grove; Richard V. Pouyat; Ian C. Yesilonis; Wayne C. Zipperer

    2003-01-01

    Riparian areas are hotspots of interactions between plants, soil, water, microbes, and people. While urban land use change has been shown to have dramatic effects on watershed hydrology, there has been surprisingly little analysis of its effects on riparian areas. Here we examine the ecology of urban riparian zones, focusing on work done in the Baltimore Ecosystem...

  4. Nitrous oxide emission from cropland and adjacent riparian buffers in contrasting hydrogeomorphic settings.

    Science.gov (United States)

    Fisher, K; Jacinthe, P A; Vidon, P; Liu, X; Baker, M E

    2014-01-01

    Riparian buffers are important nitrate (NO) sinks in agricultural watersheds, but limited information is available regarding the intensity and control of nitrous oxide (NO) emission from these buffers. This study monitored (December 2009-May 2011) NO fluxes at two agricultural riparian buffers in the White River watershed in Indiana to assess the impact of land use and hydrogeomorphologic (HGM) attributes on emission. The study sites included a riparian forest in a glacial outwash/alluvium setting (White River [WR]) and a grassed riparian buffer in tile-drained till plains (Leary Weber Ditch [LWD]). Adjacent corn ( L.) fields were monitored for land use assessment. Analysis of variance identified season, land use (riparian buffer vs. crop field), and site geomorphology as major drivers of NO fluxes. Strong relationships between N mineralization and NO fluxes were found at both sites, but relationships with other nutrient cycling indicators (C/N ratio, dissolved organic C, microbial biomass C) were detected only at LWD. Nitrous oxide emission showed strong seasonal variability; the largest NO peaks occurred in late spring/early summer as a result of flooding at the WR riparian buffer (up to 27.8 mg NO-N m d) and N fertilizer application to crop fields. Annual NO emission (kg NO-N ha) was higher in the crop fields (WR: 7.82; LWD: 6.37) than in the riparian areas. A significant difference ( LWD, respectively), and this difference was attributed to site geomorphology and flooding (WR is flood prone; no flooding occurred at tile-drained LWD). The study results demonstrate the significance of landscape geomorphology and land-stream connection (i.e., flood potential) as drivers of NO emission in riparian buffers and therefore argue that an HGM-based approach should be especially suitable for determination of regional NO budget in riparian ecosystems. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  5. Quantifying the contribution of riparian soils to the provision of ecosystem services.

    Science.gov (United States)

    de Sosa, Laura L; Glanville, Helen C; Marshall, Miles R; Prysor Williams, A; Jones, Davey L

    2018-05-15

    Riparian areas, the interface between land and freshwater ecosystems, are considered to play a pivotal role in the supply of regulating, provisioning, cultural and supporting services. Most previous studies, however, have tended to focus on intensive agricultural systems and only on a single ecosystem function. Here, we present the first study which attempts to assess a wide range of ecological processes involved in the provision of the ecosystem service of water quality regulation across a diverse range of riparian typologies. Specifically, we focus on 1) evaluating the spatial variation in riparian soils properties with respect to distance with the river and soil depth in contrasting habitat types; 2) gaining further insights into the underlying mechanisms of pollutant removal (i.e. pesticide sorption/degradation, denitrification, etc.) by riparian soils; and 3) quantify and evaluate how riparian vegetation across different habitat types contribute to the provision of watercourse shading. All the habitats were present within a single large catchment and included: (i) improved grassland, (ii) unimproved (semi-natural) grassland, (iii) broadleaf woodland, (iv) coniferous woodland, and (iv) mountain, heath and bog. Taking all the data together, the riparian soils could be statistically separated by habitat type, providing evidence that they deliver ecosystem services to differing extents. Overall, however, our findings seem to contradict the general assumption that soils in riparian area are different from neighbouring (non-riparian) areas and that they possess extra functionality in terms of ecosystem service provision. Watercourse shading was highly habitat specific and was maximal in forests (ca. 52% shade cover) in comparison to the other habitat types (7-17%). Our data suggest that the functioning of riparian areas in less intensive agricultural areas, such as those studied here, may be broadly predicted from the surrounding land use, however, further research

  6. [Dynamics of Amomum villosum growth and its fruit yield cultivated under tropical forests].

    Science.gov (United States)

    Zheng, Zheng; Gan, Jianmin; Feng, Zhili; Meng, Ying

    2004-01-01

    Investigations on the dynamics of Amomum villosum growth and its fruit yield cultivated under tropical ravine rainforest and secondary forest at different elevations in Xishuangbanna showed that the yield of A. villosum was influenced by the site age, sun light level of understorey, and water stress in dry season. The fruit yield and mature plant density decreased with increasing age of the A. villosum site. The fruit yield increased with sun light level when the light level in understorey was under 35% of full sun light (P forest was not significant. Planned cultivation of A. villosum in the secondary forest of the shifting cultivation land by ravine from 800-1000 m elevation instead of customary cultivation in the ravine rainforest, could not only resolve the problem of the effect of light deficiency in understorey and water stress in the dry season on A. villosum fruit yield, but also be useful to protect the tropical ravine rain forest.

  7. Temporal dynamics and leaf trait variability in Neotropical dry forests

    Science.gov (United States)

    Hesketh, Michael Sean

    This thesis explores the variability of leaf traits resulting from changes in season, ecosystem successional stage, and site characteristics. In chapter two, I present a review of the use of remote sensing analysis for the evaluation of Neotropical dry forests. Here, I stress the conclusion, drawn from studies on land cover characterization, biodiversity assessment, and evaluation of forest structural characteristics, that addressing temporal variability in spectral properties is an essential element in the monitoring of these ecosystems. Chapter three describes the effect of wet-dry seasonality on spectral classification of tree and liana species. Highly accurate classification (> 80%) was possible using data from either the wet or dry season. However, this accuracy decreased by a factor of ten when data from the wet season was classified using an algorithm trained on the dry, or vice versa. I also address the potential creation of a spectral taxonomy of species, but found that any clustering based on spectral properties resulted in markedly different arrangements in the wet and dry seasons. In chapter 4, I address the variation present in both physical and spectral leaf traits according to changes in forest successional stage at dry forest sites in Mexico and Costa Rica. I found significant differences in leaf traits between successional stages, but more strongly so in Costa Rica. This variability deceased the accuracy of spectral classification of tree species by a factor of four when classifying data using an algorithm trained on a different successional stage. Chapter 5 shows the influence of seasonality and succession on trait variability in Mexico. Differences in leaf traits between successional stages were found to be greater during the dry season, but were sufficient in both seasons to negatively influence spectral classification of tree species. Throughout this thesis, I show clear and unambiguous evidence of the variability of key physical and spectral

  8. Forestry best management practices relationships with aquatic and riparian fauna: A review

    Science.gov (United States)

    Warrington, Brooke M.; Aust, W. Michael; Barrett, Scott M.; Ford, W. Mark; Dolloff, C. Andrew; Schilling, Erik B.; Wigley, T. Bently; Bolding, M. Chad

    2017-01-01

    Forestry best management practices (BMPs) were developed to minimize water pollution from forestry operations by primarily addressing sediment and sediment transport, which is the leading source of pollution from silviculture. Implementation of water quality BMPs may also benefit riparian and aquatic wildlife, although wildlife benefits were not driving forces for BMP development. Therefore, we reviewed literature regarding potential contributions of sediment-reducing BMPs to conservation of riparian and aquatic wildlife, while realizing that BMPs also minimize thermal, nutrient, and chemical pollution. We reached five important conclusions: (1) a significant body of research confirms that forestry BMPs contribute to the protection of water quality and riparian forest structure; (2) data-specific relationships between forestry BMPs and reviewed species are limited; (3) forestry BMPs for forest road construction and maintenance, skid trails, stream crossings, and streamside management zones (SMZs) are important particularly for protection of water quality and aquatic species; (4) stream crossings should be carefully selected and installed to minimize sediment inputs and stream channel alterations; and (5) SMZs promote retention of older-age riparian habitat with benefits extending from water bodies to surrounding uplands. Overall, BMPs developed for protection of water quality should benefit a variety of riparian and aquatic species that are sensitive to changes in water quality or forest structure.

  9. Forestry Best Management Practices Relationships with Aquatic and Riparian Fauna: A Review

    Directory of Open Access Journals (Sweden)

    Brooke M. Warrington

    2017-09-01

    Full Text Available Forestry best management practices (BMPs were developed to minimize water pollution from forestry operations by primarily addressing sediment and sediment transport, which is the leading source of pollution from silviculture. Implementation of water quality BMPs may also benefit riparian and aquatic wildlife, although wildlife benefits were not driving forces for BMP development. Therefore, we reviewed literature regarding potential contributions of sediment-reducing BMPs to conservation of riparian and aquatic wildlife, while realizing that BMPs also minimize thermal, nutrient, and chemical pollution. We reached five important conclusions: (1 a significant body of research confirms that forestry BMPs contribute to the protection of water quality and riparian forest structure; (2 data-specific relationships between forestry BMPs and reviewed species are limited; (3 forestry BMPs for forest road construction and maintenance, skid trails, stream crossings, and streamside management zones (SMZs are important particularly for protection of water quality and aquatic species; (4 stream crossings should be carefully selected and installed to minimize sediment inputs and stream channel alterations; and (5 SMZs promote retention of older-age riparian habitat with benefits extending from water bodies to surrounding uplands. Overall, BMPs developed for protection of water quality should benefit a variety of riparian and aquatic species that are sensitive to changes in water quality or forest structure.

  10. Influence of different forest system management practices on leaf litter decomposition rates, nutrient dynamics and the activity of ligninolytic enzymes: a case study from central European forests.

    Science.gov (United States)

    Purahong, Witoon; Kapturska, Danuta; Pecyna, Marek J; Schulz, Elke; Schloter, Michael; Buscot, François; Hofrichter, Martin; Krüger, Dirk

    2014-01-01

    Leaf litter decomposition is the key ecological process that determines the sustainability of managed forest ecosystems, however very few studies hitherto have investigated this process with respect to silvicultural management practices. The aims of the present study were to investigate the effects of forest management practices on leaf litter decomposition rates, nutrient dynamics (C, N, Mg, K, Ca, P) and the activity of ligninolytic enzymes. We approached these questions using a 473 day long litterbag experiment. We found that age-class beech and spruce forests (high forest management intensity) had significantly higher decomposition rates and nutrient release (most nutrients) than unmanaged deciduous forest reserves (Pforest management (low forest management intensity) exhibited no significant differences in litter decomposition rate, C release, lignin decomposition, and C/N, lignin/N and ligninolytic enzyme patterns compared to the unmanaged deciduous forest reserves, but most nutrient dynamics examined in this study were significantly faster under such near-to-nature forest management practices. Analyzing the activities of ligninolytic enzymes provided evidence that different forest system management practices affect litter decomposition by changing microbial enzyme activities, at least over the investigated time frame of 473 days (laccase, Pforest system management practices can significantly affect important ecological processes and services such as decomposition and nutrient cycling.

  11. The role of gap phase processes in the biomass dynamics of tropical forests

    Science.gov (United States)

    Feeley, Kenneth J; Davies, Stuart J; Ashton, Peter S; Bunyavejchewin, Sarayudh; Nur Supardi, M.N; Kassim, Abd Rahman; Tan, Sylvester; Chave, Jérôme

    2007-01-01

    The responses of tropical forests to global anthropogenic disturbances remain poorly understood. Above-ground woody biomass in some tropical forest plots has increased over the past several decades, potentially reflecting a widespread response to increased resource availability, for example, due to elevated atmospheric CO2 and/or nutrient deposition. However, previous studies of biomass dynamics have not accounted for natural patterns of disturbance and gap phase regeneration, making it difficult to quantify the importance of environmental changes. Using spatially explicit census data from large (50 ha) inventory plots, we investigated the influence of gap phase processes on the biomass dynamics of four ‘old-growth’ tropical forests (Barro Colorado Island (BCI), Panama; Pasoh and Lambir, Malaysia; and Huai Kha Khaeng (HKK), Thailand). We show that biomass increases were gradual and concentrated in earlier-phase forest patches, while biomass losses were generally of greater magnitude but concentrated in rarer later-phase patches. We then estimate the rate of biomass change at each site independent of gap phase dynamics using reduced major axis regressions and ANCOVA tests. Above-ground woody biomass increased significantly at Pasoh (+0.72% yr−1) and decreased at HKK (−0.56% yr−1) independent of changes in gap phase but remained stable at both BCI and Lambir. We conclude that gap phase processes play an important role in the biomass dynamics of tropical forests, and that quantifying the role of gap phase processes will help improve our understanding of the factors driving changes in forest biomass as well as their place in the global carbon budget. PMID:17785266

  12. Spatial variation in population dynamics of Sitka mice in floodplain forests.

    Science.gov (United States)

    T.A. Hanley; J.C. Barnard

    1999-01-01

    Population dynamics and demography of the Sitka mouse, Peromyscus keeni sitkensis, were studied by mark-recapture live-trapping over a 4-year period in four floodplain and upland forest habitats: old-growth Sitka spruce (Picea sitchensis) floodplain; red alder (Alnus rubra) floodplain; beaver-pond...

  13. Crown dynamics and wood production of Douglas-fir trees in an old-growth forest

    Science.gov (United States)

    H. Roaki Ishii; Stephen C. Sillett; Allyson L. Carroll

    2017-01-01

    Large trees are the most prominent structural features of old-growth forests, which are considered to be globally important carbon sinks. Because of their large size, estimates of biomass and growth of large trees are often based on ground-level measurements (e.g., diameter at breast height, DBH) and little is known about growth dynamics within the crown. As trees...

  14. Fine root dynamics and trace gas fluxes in two lowland tropical forest soils.

    Science.gov (United States)

    WHENDEE L. SILVER; ANDREW W. THOMPSON; MEGAN E . MCGRODDY; RUTH K. VARNER; JADSON D. DIAS; HUDSON SILVA; CRILL PATRICK M.; MICHAEL KELLER

    2005-01-01

    Fine root dynamics have the potential to contribute significantly to ecosystem-scale biogeochemical cycling, including the production and emission of greenhouse gases. This is particularly true in tropical forests which are often characterized as having large fine root biomass and rapid rates of root production and decomposition. We examined patterns in fine root...

  15. Tree dynamics in canopy gaps in old-growth forests of Nothofagus pumilio in Southern Chile

    NARCIS (Netherlands)

    Fajardo, Alex; Graaf, de N.R.

    2004-01-01

    The gap dynamics of two Nothofagus pumilio (lenga) stands have been investigated. We evaluated and compared tree diameter distributions, spatial patterns, tree fall and gap characteristics and regeneration responses in gaps in two old-growth forests of Nothofagus pumilio in Southern Chile

  16. Amazon forest carbon dynamics predicted by profiles of canopy leaf area and light environment

    Science.gov (United States)

    S. C. Stark; V. Leitold; J. L. Wu; M. O. Hunter; C. V. de Castilho; F. R. C. Costa; S. M. McMahon; G. G. Parker; M. Takako Shimabukuro; M. A. Lefsky; M. Keller; L. F. Alves; J. Schietti; Y. E. Shimabukuro; D. O. Brandao; T. K. Woodcock; N. Higuchi; P. B de Camargo; R. C. de Oliveira; S. R. Saleska

    2012-01-01

    Tropical forest structural variation across heterogeneous landscapes may control above-ground carbon dynamics. We tested the hypothesis that canopy structure (leaf area and light availability) – remotely estimated from LiDAR – control variation in above-ground coarse wood production (biomass growth). Using a statistical model, these factors predicted biomass growth...

  17. Effects of harvest on carbon and nitrogen dynamics in a Pacific Northwest forest catchment

    Science.gov (United States)

    We used a new ecohydrological model, Visualizing Ecosystems for Land Management Assessments (VELMA), to analyze the effects of forest harvest on catchment carbon and nitrogen dynamics. We applied the model to a 10 ha headwater catchment in the western Oregon Cascade Range where t...

  18. Time series analysis of forest carbon dynamics: recovery of Pinus palustris physiology following a prescribed fire

    Science.gov (United States)

    G. Starr; C. L. Staudhammer; H. W. Loescher; R. Mitchell; A. Whelan; J. K. Hiers; J. J. O’Brien

    2015-01-01

    Frequency and intensity of fire determines the structure and regulates the function of savanna ecosystems worldwide, yet our understanding of prescribed fire impacts on carbon in these systems is rudimentary. We combined eddy covariance (EC) techniques and fuel consumption plots to examine the short-term response of longleaf pine forest carbon dynamics to one...

  19. Shape selection in Landsat time series: A tool for monitoring forest dynamics

    Science.gov (United States)

    Gretchen G. Moisen; Mary C. Meyer; Todd A. Schroeder; Xiyue Liao; Karen G. Schleeweis; Elizabeth A. Freeman; Chris Toney

    2016-01-01

    We present a new methodology for fitting nonparametric shape-restricted regression splines to time series of Landsat imagery for the purpose of modeling, mapping, and monitoring annual forest disturbance dynamics over nearly three decades. For each pixel and spectral band or index of choice in temporal Landsat data, our method delivers a smoothed rendition of...

  20. Strong persistent growth differences govern individual performance and population dynamics in a tropical forest understorey palm

    NARCIS (Netherlands)

    Jansen, M.; Zuidema, P.A.; Anten, N.P.R.; Martínez-Ramos, M.

    2012-01-01

    1. Persistent variation in growth rate between individual plants can have strong effects on population dynamics as fast growers reach the reproductive size at an earlier age and thus potentially contribute more to population growth than slow growers. In tropical forests, such persistent growth

  1. Influence of climate change factors on carbon dynamics in northern forested peatlands

    Science.gov (United States)

    C.C Trettin; R. Laiho; K. Minkkinen; J. Laine

    2005-01-01

    Peatlands are carbon-accumulating wetland ecosystems, developed through an imbalance among organic matter production and decomposition processes. Soil saturation is the principal cause of anoxic conditions that constrain organic matter decay. Accordingly, changes in the hydrologic regime will affect the carbon (C) dynamics in forested peatlands. Our objective is to...

  2. Required sample size for monitoring stand dynamics in strict forest reserves: a case study

    Science.gov (United States)

    Diego Van Den Meersschaut; Bart De Cuyper; Kris Vandekerkhove; Noel Lust

    2000-01-01

    Stand dynamics in European strict forest reserves are commonly monitored using inventory densities of 5 to 15 percent of the total surface. The assumption that these densities guarantee a representative image of certain parameters is critically analyzed in a case study for the parameters basal area and stem number. The required sample sizes for different accuracy and...

  3. Stream carbon dynamics in low-gradient headwaters of a forested watershed

    Science.gov (United States)

    April Bryant-Mason; Y. Jun Xu; Johnny M. Grace

    2013-01-01

    Headwater streams drain more than 70 percent of the total watershed area in the United States. Understanding of carbon dynamics in the headwater systems is of particular relevance for developing best silvicultural practices to reduce carbon export. This study was conducted in a low-gradient, predominantly forested watershed located in the Gulf Coastal Plain region, to...

  4. Wildfire and drought dynamics destabilize carbon stores of fire-suppressed forests

    Science.gov (United States)

    J. Mason Earles; Malcolm P. North; Matthew D. Hurteau

    2014-01-01

    Widespread fire suppression and thinning have altered the structure and composition of many forests in the western United States, making them more susceptible to the synergy of large-scale drought and fire events. We examine how these changes affect carbon storage and stability compared to historic fire-adapted conditions. We modeled carbon dynamics under possible...

  5. Short-term dynamics of second-growth mixed mesophytic forest strata in West Virginia

    Science.gov (United States)

    Cynthia C. Huebner; Steven L. Stephenson; Harold S. Adams; Gary W. Miller

    2007-01-01

    The short-term dynamics of mixed mesophytic forest strata in West Virginia were examined using similarity analysis and linear correlation of shared ordination space. The overstory tree, understory tree, shrub/vine, and herb strata were stable over a six year interval, whereas the tree seedling and sapling strata were unstable. All strata but the shrub/vine and tree...

  6. Human impacts on soil carbon dynamics of deep-rooted Amazonian forests

    Science.gov (United States)

    Nepstad, Daniel C.; Stone, Thomas A.; Davidson, Eric A.

    1994-01-01

    Deforestation and logging degrade more forest in eastern and southern Amazonia than in any other region of the world. This forest alteration affects regional hydrology and the global carbon cycle, but our current understanding of these effects is limited by incomplete knowledge of tropical forest ecosystems. It is widely agreed that roots are concentrated near the soil surface in moist tropical forests, but this generalization incorrectly implies that deep roots are unimportant in water and C budgets. Our results indicate that half of the closed-canopy forests of Brazilian Amazonic occur where rainfall is highly seasonal, and these forests rely on deeply penetrating roots to extract soil water. Pasture vegetation extracts less water from deep soil than the forest it replaces, thus increasing rates of drainage and decreasing rates of evapotranspiration. Deep roots are also a source of modern carbon deep in the soil. The soils of the eastern Amazon contain more carbon below 1 m depth than is present in above-ground biomass. As much as 25 percent of this deep soil C could have annual to decadal turnover times and may be lost to the atmosphere following deforestation. We compared the importance of deep roots in a mature, evergreen forest with an adjacent man-made pasture, the most common type of vegetation on deforested land in Amazonia. The study site is near the town of Paragominas, in the Brazilian state of Para, with a seasonal rainfall pattern and deeply-weathered, kaolinitic soils that are typical for large portions of Amazonia. Root distribution, soil water extraction, and soil carbon dynamics were studied using deep auger holes and shafts in each ecosystem, and the phenology and water status of the leaf canopies were measured. We estimated the geographical distribution of deeply-rooting forests using satellite imagery, rainfall data, and field measurements.

  7. Fine root dynamics in moso bamboo and Japanese cedar forest by scanner method in central Taiwan

    Science.gov (United States)

    Chen, Zhi-Wei; Lin, Po-Hsuan; Kume, Tomonori

    2017-04-01

    Phyllostachys pubescens is one of the most important economic plant in the world. Phyllostachys pubescens originates from China and it had been introduced to neighbor countries about three hundred ago due to its economic value. But substantial bamboo forests were abandoned due to declines in demand. These unmanaged bamboo forests have been expanding to adjacent original forests in northern Taiwan. This vegetation alternation may not only decrease the local biodiversity but also affect the carbon cycle. Fine roots are responsible for water and nutrients acquisition and forming the most active part of the whole root system. The characteristics of fine roots are non-woody, small diameter and short lifespan. When roots keep producing new roots and replacing old roots, carbon and nutrients was transported into soil. Consequently, fine root production is one of the important component to understand the below-ground carbon cycle. However, there is few studies about fine root production in moso bamboo forests. We still lack effective method to obtain quantitative and objective data in Taiwan. It severely limits us to understand the below-ground carbon dynamics there. Minirhizotrons method has been used to investigate fine root dynamics by inserting transparent tubes into soil and by comparing changes in root length in images taken by micro-camera. But this method has some shortcomings; i.e. Most of image analysis are conducted manually and time-consuming. And it is difficult to estimate the stand level fine root production from small observation view. A new method "scanner method", which collect A4-size image (bigger than minirhizotrons) can overcome some parts of the shortcoming of minirhizotrons. The transparent acrylic box with A4-box view is inserted into soil and the interface between soil and box is scanned by commercial scanner. We can monitor the total projected root area, growth and decomposition separately by series of images. The primary objective of this study

  8. Dynamic and inertial controls on forest carbon-water relations

    Science.gov (United States)

    Maxwell, T.; Silva, L.; Horwath, W. R.

    2017-12-01

    This study fuses theory, empirical measurements, and statistical models to evaluate multiple processes controlling coupled carbon-water cycles in forest ecosystems. A series of latitudinal and altitudinal transects across the California Sierra Nevada was used to study the effects of climatic and edaphic gradients on intrinsic water-use efficiency (iWUE) - CO2 fixed per unit of water lost via transpiration - of nine dominant trees species. Transfer functions were determined between leaf, litter, and soil organic matter stable isotope ratios of carbon, oxygen, and nitrogen, revealing causal links between the physiological performance of tree species and stand-level estimations of productivity and water balance. Our results show that species iWUE is governed both by leaf traits (24% of the variation) and edaphic properties, such as parent material and soil development (3% and 12% of the variation, respectively). We show that soil properties combined with isotopic indicators can be used to explain constraints over iWUE by regulating water and nutrient availability across elevation gradients. Based on observed compositional shifts likely driven by changing climates in the region, encroachment of broad leaf trees could lead to an 80% increase in water loss via transpiration for each unit of CO2 fixed in Sierra mixed conifer zones. A combination of field-based, laboratory, and remote sensed data provide a useful framework for differentiating the effect of multiple controls of carbon and water cycles in temperate forest ecosystems.

  9. Niche construction within riparian corridors. Part I: Exploring biogeomorphic feedback windows of three pioneer riparian species (Allier River, France)

    Science.gov (United States)

    Hortobágyi, Borbála; Corenblit, Dov; Steiger, Johannes; Peiry, Jean-Luc

    2018-03-01

    Within riparian corridors, biotic-abiotic feedback mechanisms occur between woody vegetation strongly influenced by hydrogeomorphic constraints (e.g., sediment transport and deposition, shear stress, hydrological variability), fluvial landforms, and morphodynamics, which in turn are modulated by the established vegetation. During field investigations in spring 2015, we studied 16 alluvial bars (e.g., point and lateral bars) within the dynamic riparian corridor of the Allier River (France) to assess the aptitude of three pioneer riparian Salicaceae species (Populus nigra L., Salix purpurea L., and Salix alba L.) to establish and act as ecosystem engineers by trapping sediment and constructing fluvial landforms. Our aim is to empirically identify the preferential establishment area (EA; i.e., the local areas where species become established) and the preferential biogeomorphic feedback window (BFW; i.e., where and to what extent the species and geomorphology interact) of these three species on alluvial bars within a 20-km-long river reach. Our results show that the EA and BFW of all three species vary significantly along the longitudinal profile, i.e., upstream-downstream exposure on the alluvial bars, as well as transversally, i.e., the main hydrological connectivity gradient from the river channel toward the floodplain. In the present-day context of the Allier River, P. nigra is the most abundant species, appearing to act as the main engineer species affecting landform dynamics at the bar scale; S. purpurea is established and acts as an ecosystem engineer at locations on alluvial bars that are most exposed to hydrosedimentary flow dynamics, while S. alba is established on the bar tail close to secondary channels and affects the geomorphology in mixed patches along with P. nigra. Our study highlights the role of functional trait diversity of riparian engineer species in controlling the extent of fluvial landform construction along geomorphic gradients within riparian

  10. Evaluation of sampling methods to quantify abundance of hardwoods and snags within conifer-dominated riparian zones

    Science.gov (United States)

    Theresa Marquardt; Hailemariam Temesgen; Paul D. Anderson; Bianca. Eskelson

    2012-01-01

    Six sampling alternatives were examined for their ability to quantify selected attributes of snags and hardwoods in conifer-dominated riparian areas of managed headwater forests in western Oregon. Each alternative was simulated 500 times at eight headwater forest locations based on a 0.52-ha square stem map. The alternatives were evaluated based on how well they...

  11. Density management and riparian buffer study in Western Oregon: Phase 1 results, launch of phase 2 [brochure

    Science.gov (United States)

    Rhonda Mazza

    2009-01-01

    Can we expedite the development of late-successional forest conditions by applying thinning treatments to young forest stands? What effect will these thinning treatments have on headwater ecosystems? These broad questions lie at the foundation of the Density Management and Riparian Buffer Study (DMS) of western Oregon.

  12. Land cover change and remote sensing: Examples of quantifying spatiotemporal dynamics in tropical forests

    Energy Technology Data Exchange (ETDEWEB)

    Krummel, J.R.; Su, Haiping [Argonne National Lab., IL (United States); Fox, J. [East-West Center, Honolulu, HI (United States); Yarnasan, S.; Ekasingh, M. [Chiang Mai Univ. (Thailand)

    1995-06-01

    Research on human impacts or natural processes that operate over broad geographic areas must explicitly address issues of scale and spatial heterogeneity. While the tropical forests of Southeast Asia and Mexico have been occupied and used to meet human needs for thousands of years, traditional forest management systems are currently being transformed by rapid and far-reaching demographic, political, economic, and environmental changes. The dynamics of population growth, migration into the remaining frontiers, and responses to national and international market forces result in a demand for land to produce food and fiber. These results illustrate some of the mechanisms that drive current land use changes, especially in the tropical forest frontiers. By linking the outcome of individual land use decisions and measures of landscape fragmentation and change, the aggregated results shows the hierarchy of temporal and spatial events that in summation result in global changes to the most complex and sensitive biome -- tropical forests. By quantifying the spatial and temporal patterns of tropical forest change, researchers can assist policy makers by showing how landscape systems in these tropical forests are controlled by physical, biological, social, and economic parameters.

  13. Forest Management and the Evolution of Project Design in Dynamic Wildland Urban Interface Fire Environments

    Science.gov (United States)

    Conway, S.

    2014-12-01

    The Truckee Ranger District on the Tahoe National Forest, in the heart of the Sierra Nevada Mountains, has a rich history of human activities. Native American influences, comstock-era logging, fire suppression, development, and recreation have all shaped the natural environment into what it is today. Like much of our national forests in California, forest conditions that have developed are generally much more homogenous and less resistant to disturbance from fire, insect, and disease than they might have been without the myriad of human influences. However, in order to improve the resiliency of our forests to stand replacing disturbances like high severity fire, while managing for integrated anthropomorphic values, it is imperative that management evolve to meet those dynamic needs. Recent advances in remote sensing and GIS allow land managers more access to forest information and can inform site specific prescriptions to change site specific undesirable conditions. It is ecologically and politically complex, yet our forests deserve that microscope. This particular presentation will focus on how the Truckee Ranger District began this process of incorporating several values, generated from stakeholder collaboration, into one project's goals and how those lessons learned informed their most recent project.

  14. A neighborhood analysis of the consequences of Quercus suber decline for regeneration dynamics in Mediterranean forests.

    Directory of Open Access Journals (Sweden)

    Beatriz Ibáñez

    Full Text Available In forests, the vulnerable seedling stage is largely influenced by the canopy, which modifies the surrounding environment. Consequently, any alteration in the characteristics of the canopy, such as those promoted by forest dieback, might impact regeneration dynamics. Our work analyzes the interaction between canopy neighbors and seedlings in Mediterranean forests affected by the decline of their dominant species (Quercus suber. Our objective was to understand how the impacts of neighbor trees and shrubs on recruitment could affect future dynamics of these declining forests. Seeds of the three dominant tree species (Quercus suber, Olea europaea and Quercus canariensis were sown in six sites during two consecutive years. Using a spatially-explicit, neighborhood approach we developed models that explained the observed spatial variation in seedling emergence, survival, growth and photochemical efficiency as a function of the size, identity, health, abundance and distribution of adult trees and shrubs in the neighborhood. We found strong neighborhood effects for all the performance estimators, particularly seedling emergence and survival. Tree neighbors positively affected emergence, independently of species identity or health. Alternatively, seedling survival was much lower in neighborhoods dominated by defoliated and dead Q. suber trees than in neighborhoods dominated by healthy trees. For the two oak species, these negative effects were consistent over the three years of the experimental seedlings. These results indicate that ongoing changes in species' relative abundance and canopy trees' health might alter the successional trajectories of Mediterranean oak-forests through neighbor-specific impacts on seedlings. The recruitment failure of dominant late-successional oaks in the gaps opened after Q. suber death would indirectly favor the establishment of other coexisting woody species, such as drought-tolerant shrubs. This could lead current

  15. Perspectives for the application of computer models to forest dynamics forecasting in bieszczadzki national park (Poland

    Directory of Open Access Journals (Sweden)

    Kozak Ihor

    2014-03-01

    Full Text Available This paper presents the perspectives for application of computer models in forecasting the dynamics of forest development on example of Moczarne area, in Bieszczadzki National Park, based on authors’ computer models. First, the possibilities for forecasting the dynamics of forest development in a local scale, i.e. within single rectangular or circular study plot, are presented. For this purpose, a computer prognostic model FORKOM E has been applied, using both general mathematical relationships functioning within a forest ecosystem and empirical ones, characteristic for tree stands at analysed plots. Additionally, a layer of 3D visualisation of a tree stand, which is an integral part of the mentioned model, is also presented. Presented also are the possibilities for forecasting the dynamics of forest development at landscape scale, applying the theory of cellular automata. For this purpose, a prognostic computer model CELLAUT was used in which the whole analysed tree stand is understood as a set of single cells, where stages of landscape development dominating within those cells are considered as also the influence of particular cells upon their neighbours. The paper also describes the perspectives for application of self-learning neural networks in the process of supplementation and verification of some parameters of a tree stand, calculated by the above-mentioned models.

  16. State-and-transition prototype model of riparian vegetation downstream of Glen Canyon Dam, Arizona

    Science.gov (United States)

    Ralston, Barbara E.; Starfield, Anthony M.; Black, Ronald S.; Van Lonkhuyzen, Robert A.

    2014-01-01

    Facing an altered riparian plant community dominated by nonnative species, resource managers are increasingly interested in understanding how to manage and promote healthy riparian habitats in which native species dominate. For regulated rivers, managing flows is one tool resource managers consider to achieve these goals. Among many factors that can influence riparian community composition, hydrology is a primary forcing variable. Frame-based models, used successfully in grassland systems, provide an opportunity for stakeholders concerned with riparian systems to evaluate potential riparian vegetation responses to alternative flows. Frame-based, state-and-transition models of riparian vegetation for reattachment bars, separation bars, and the channel margin found on the Colorado River downstream of Glen Canyon Dam were constructed using information from the literature. Frame-based models can be simple spreadsheet models (created in Microsoft® Excel) or developed further with programming languages (for example, C-sharp). The models described here include seven community states and five dam operations that cause transitions between states. Each model divides operations into growing (April–September) and non-growing seasons (October–March) and incorporates upper and lower bar models, using stage elevation as a division. The inputs (operations) can be used by stakeholders to evaluate flows that may promote dynamic riparian vegetation states, or identify those flow options that may promote less desirable states (for example, Tamarisk [Tamarix sp.] temporarily flooded shrubland). This prototype model, although simple, can still elicit discussion about operational options and vegetation response.

  17. [Distribution pattern of rare plants along riparian zone and its implication for conservation in Shennongjia area].

    Science.gov (United States)

    Jiang, Mingxi; Deng, Hongbing; Cai, Qinghua

    2002-11-01

    Due to the importance of riparian zone in maintaining and protecting regional biodiversity, more and more ecologists paid their attentions to riparian zone, and had been aware of the important effects of riparian zone in basic study and practical management. In this study, forty sampling belts (10 m x 100 m) parallel to the bank of Xiangxi River at different elevations in Shennongjia area were selected to investigate the riparian vegetation and rare plants. Fourteen species of rare plants were found in riparian zone, accounting for 42.4% of total rare plant species in Shennongjia area. The main distribution range of the fourteen rare plant species was the mixed evergreen and deciduous broadleaved forest at elevation of 1200-1800 m, where species diversity of plant community was the maximum at the moderate elevation. Fourteen rare plant species could be divided into three groups against the elevation, namely low elevation species group, moderate elevation species group, and high elevation group. In the paper, the authors discussed the reasons forming the distribution pattern of rare plant species, and pointed out the important function of riparian zone on rare plant species protection.

  18. Woody riparian vegetation response to different alluvial water table regimes

    Science.gov (United States)

    Shafroth, P.B.; Stromberg, J.C.; Patten, D.T.

    2000-01-01

    Woody riparian vegetation in western North American riparian ecosystems is commonly dependent on alluvial groundwater. Various natural and anthropogenic mechanisms can cause groundwater declines that stress riparian vegetation, but little quantitative information exists on the nature of plant response to different magnitudes, rates, and durations of groundwater decline. We observed groundwater dynamics and the response of Populus fremontii, Salix gooddingii, and Tamarix ramosissima saplings at 3 sites between 1995 and 1997 along the Bill Williams River, Arizona. At a site where the lowest observed groundwater level in 1996 (-1.97 m) was 1.11 m lower than that in 1995 (-0.86 m), 92-100% of Populus and Salix saplings died, whereas 0-13% of Tamarix stems died. A site with greater absolute water table depths in 1996 (-2.55 m), but less change from the 1995 condition (0.55 m), showed less Populus and Salix mortality and increased basal area. Excavations of sapling roots suggest that root distribution is related to groundwater history. Therefore, a decline in water table relative to the condition under which roots developed may strand plant roots where they cannot obtain sufficient moisture. Plant response is likely mediated by other factors such as soil texture and stratigraphy, availability of precipitation-derived soil moisture, physiological and morphological adaptations to water stress, and tree age. An understanding of the relationships between water table declines and plant response may enable land and water managers to avoid activities that are likely to stress desirable riparian vegetation.

  19. Dynamics of forest herbivory: quest for pattern and principle.

    Science.gov (United States)

    William J. Mattson; Pekka Niemila; Matti Rossi

    1996-01-01

    Herbivory on woody plants is highly variable in both space and time. This proceedings addresses one of its root causes, the highly intricate and dynamic relationships that exist between most herbivores and their host plants. It emphasizes that the consequences of herbivory both to the consumer and to the producer plant often balance on a razor`s edge--depending on...

  20. Great Basin Research and Management Project: Restoring and maintaining riparian ecosystem integrity

    Science.gov (United States)

    Jeanne C. Chambers

    2000-01-01

    The Great Basin Research and Management Project was initiated in 1994 by the USDA Forest Service, Rocky Mountain Research Station’s Ecology, Paleoecology, and Restoration of Great Basin Watersheds Project to address the problems of stream incision and riparian ecosystem degradation in central Nevada. It is a highly interdisciplinary project that is being conducted in...

  1. The riparian ecosystem management study: response of small mammals to streamside buffers in western Washington

    Science.gov (United States)

    Martin G. Raphael; Randall J. Wilk

    2013-01-01

    One of the fundamental concepts behind the conservation strategy in the U.S. federal Northwest Forest Plan is the importance of habitat buff ers in providing functional stream and streamside ecosystems. To better understand the importance of riparian buff ers in providing habitat for associated organisms, we investigated responses of small mammals to various streamside...

  2. Riparian influences on the biophysical characteristics of seston in headwater streams.

    Science.gov (United States)

    Scott R. Elliott; Robert J. Naiman; Peter A. Bisson

    2004-01-01

    Suspended particles (seston) in streams are an important source of nutrition for many invertebrates, forming a strong trophic link between plant and animal production. In forested regions the management of riparian corridors may alter alloehthonous and autochthonous contributions to streams, ultimately changing the biophysical characteristics of seston. This article...

  3. High temporal resolution photography for observing riparian area use and grazing behavior

    Science.gov (United States)

    In 2014, a 2.4 hectare site within the Apache-Sitgreaves National Forest in northeastern Arizona, USA was selected to characterize temporal and spatial patterns of riparian area use. Three consecutive 30, 8, and 46 day time periods representing 1) unrestricted access, 2) prescribed cattle use, and 3...

  4. Riparian ecotone: A functional definition and delineation for resource assessment

    Science.gov (United States)

    E. S Verry; C. A Dolloff; M. E. Manning

    2004-01-01

    We propose a geomorphic basis for defining riparian areas using the term: riparian ecotone, discuss how past definitions fall short, and illustrate how a linked sequence of definition, delineation, and riparian sampling are used to accurately assess riparian resources on the ground. Our riparian ecotone is based on the width of the valley (its floodprone area width)...

  5. Main dynamics and drivers of boreal forests fire regimes during the Holocene

    Science.gov (United States)

    Molinari, Chiara; Lehsten, Veiko; Blarquez, Olivier; Clear, Jennifer; Carcaillet, Christopher; Bradshaw, Richard HW

    2015-04-01

    Forest fire is one of the most critical ecosystem processes in the boreal megabiome, and it is likely that its frequency, size and severity have had a primary role in vegetation dynamics since the Last Ice Age (Kasischke & Stocks 2000). Fire not only organizes the physical and biological attributes of boreal forests, but also affects biogeochemical cycling, particularly the carbon balance (Balshi et al. 2007). Due to their location at climatically sensitive northern latitudes, boreal forests are likely to be significantly affected by global warming with a consequent increase in biomass burning (Soja et al. 2007), a variation in vegetation structure and composition (Johnstone et al. 2004) and a rise in atmospheric carbon dioxide concentration (Bond-Lamberty et al. 2007). Even if the ecological role of wildfire in boreal forest is widely recognized, a clearer understanding of the environmental factors controlling fire dynamics and how variations in fire regimes impact forest ecosystems is essential in order to place modern fire processes in a meaningful context for projecting ecosystem behaviour in a changing environment (Kelly et al. 2013). Because fire return intervals and successional cycles in boreal forests occur over decadal to centennial timescales (Hu et al. 2006), palaeoecological research seems to be one of the most promising tool for elucidating ecosystem changes over a broad range of environmental conditions and temporal scales. Within this context, our first aim is to reconstruct spatial and temporal patterns of boreal forests fire dynamics during the Holocene based on sedimentary charcoal records. As a second step, trends in biomass burning will be statistically analysed in order to disentangle between regional and local drivers. The use of European and north-American sites will give us the unique possibility to perform a large scale analysis on one of the broadest biome in the world and to underline the different patterns of fire in these two

  6. Dynamic model of forest area on flood zone of Padang City, West Sumatra Province-Indonesia

    Science.gov (United States)

    Dewata, Indang; Iswandi, U.

    2018-05-01

    The flood disaster has caused many harm to human life, and the change of watershed characteristic is one of the factors causing the flood disaster. The increase of deforestation due to the increase of water causes the occurrence of flood disaster in the rainy season. The research objective was to develop a dynamic model of forest on flood hazard zone using powersim 10.1. In model development, there are three scenarios: optimistic, moderate, and pessimistic. The study shows that in Padang there are about 13 percent of high flood hazard zones. Deforestation of 4.5 percent/year is one cause that may increased the flooding intensity in Padang. There will be 14 percent of total forest area when management policy of forest absence in 2050.

  7. Population dynamics of the epiphytic bromeliad Tillandsia butzii in cloud forest

    Science.gov (United States)

    Toledo-Aceves, Tarin; Hernández-Apolinar, Mariana

    2016-02-01

    Epiphytes are a major component of tropical montane cloud forests. Over-exploitation and forest loss and degradation affect remnant populations. In this study, we analysed the population dynamics of the epiphytic bromeliad Tillandsia butzii over a 2-y period in a tropical montane cloud forest fragment in southern Mexico. Matrix analysis revealed that the T. butzii population is likely to be stable at the study site. On average the λ value did not differ significantly from unity: λ (95% confidence interval) = 0.978 (0.936-1.001). λ was highly influenced by stasis, to a lesser extent by growth and only slightly by fecundity. Overall, adult plant stasis and phalanx growth habit played a fundamental role in population maintenance. T. butzii tolerance to xeric conditions may contribute to population stability in the studied region.

  8. Linking stream flow and groundwater to avian habitat in a desert riparian system.

    Science.gov (United States)

    Merritt, David M; Bateman, Heather L

    2012-10-01

    Increasing human populations have resulted in aggressive water development in arid regions. This development typically results in altered stream flow regimes, reduced annual flow volumes, changes in fluvial disturbance regimes, changes in groundwater levels, and subsequent shifts in ecological patterns and processes. Balancing human demands for water with environmental requirements to maintain functioning ecosystems requires quantitative linkages between water in streams and ecosystem attributes. Streams in the Sonoran Desert provide important habitat for vertebrate species, including resident and migratory birds. Habitat structure, food, and nest-building materials, which are concentrated in riparian areas, are provided directly or indirectly by vegetation. We measured riparian vegetation, groundwater and surface water, habitat structure, and bird occurrence along Cherry Creek, a perennial tributary of the Salt River in central Arizona, USA. The purpose of this work was to develop an integrated model of groundwater-vegetation-habitat structure and bird occurrence by: (1) characterizing structural and provisioning attributes of riparian vegetation through developing a bird habitat index (BHI), (2) validating the utility of our BHI through relating it to measured bird community composition, (3) determining the riparian plant species that best explain the variability in BHI, (4) developing predictive models that link important riparian species to fluvial disturbance and groundwater availability along an arid-land stream, and (5) simulating the effects of changes in flow regime and groundwater levels and determining their consequences for riparian bird communities. Riparian forest and shrubland vegetation cover types were correctly classified in 83% of observations as a function of fluvial disturbance and depth to water table. Groundwater decline and decreased magnitude of fluvial disturbance caused significant shifts in riparian cover types from riparian forest to

  9. Tree diversity, composition, forest structure and aboveground biomass dynamics after single and repeated fire in a Bornean rain forest

    NARCIS (Netherlands)

    Slik, J.W.F.; Bernard, C.S.; Beek, van M.; Breman, F.C.; Eichhorn, K.A.O.

    2008-01-01

    Forest fires remain a devastating phenomenon in the tropics that not only affect forest structure and biodiversity, but also contribute significantly to atmospheric CO2. Fire used to be extremely rare in tropical forests, leaving ample time for forests to regenerate to pre-fire conditions. In recent

  10. Trends in dynamics of forest upper boundary in high mountains of northern Baikal area

    Directory of Open Access Journals (Sweden)

    V. I. Voronin

    2016-08-01

    Full Text Available Studies of spatial-temporal variability of the upper boundary of the forest on the north-western coast of Lake Baikal (Baikal and Upper Angara Ridges are performed on the base of the analysis of forests renewal processes and of the dynamics of larch radial increment in the ecotone of the forest upper boundary and out of it. The presence of a large amount of well-developed uplands and circuses with considerable heights drops in the structure of mountain system favours formation of interrupted boundary between forest and subgoltsy belt. The timber stand of the upper forest boundary in the studied area is represented by Daurian larch. Three tree-ring chronologies of larch are obtained. The longest chronology is obtained for mountain taiga belt of Baikal Ridge and is as long as 460 years. Since 1980ies, a sustainable trend of increase of radial trees growth is observed. It is observed the most distinctly in trees of the upper forest boundary on the Baikal Ridge. There is advancing of trees species into subgoltsy belt and into mountain tundra, which depends, respectively, on slopes heights, exposition and tilting, on sites of growth of concrete cenoses. Modern peculiarity of the vegetation of the studied area is presence of abundant viable larch undergrowth (from 2–3 to 25 y.o. and fir in the ecotone of upper forest boundary and in subgoltsy belt, as well as appearing of single specimens of spruce. Main undergrowth mass (2/3 is presented by trees aged in average 15–25 y.o., i.e., they appeared in late 1980ies. Due to increase of snow cover thickness in winter, the trees young growth obtained great protection from freezing resulting in the increase of ability of young growth to live up to elder age.

  11. Forest - water dynamics in a Mediterranean mountain environment.

    Science.gov (United States)

    Eliades, Marinos; Bruggeman, Adriana; Lange, Manfred; Camera, Corrado; Christou, Andreas

    2015-04-01

    In semi-arid Mediterranean mountain environments, the soil layer is very shallow or even absent due to the steep slopes. Soil moisture in these environments is limited, but still vegetation thrives. There is limited knowledge about where the vegetation extracts the water from, how much water it uses, and how it interacts with other processes in the hydrological cycle. The main objective of this study is to quantify the water balance components of a Pinus brutia forest at tree level, by measuring the tree transpiration and the redistribution of the water from trees to the soil and the bedrock fractures. The study area is located on a forested hill slope on the outside edge of Peristerona watershed in Cyprus. The site was mapped with the use of a total station and a differentially-corrected GPS, in order to create a high resolution DEM and soil depth map of the area. Soil depth was measured at a 1-m grid around the trees. Biometric measurements were taken from a total of 45 trees. Four trees were selected for monitoring. Six sap flow sensors are installed in the selected trees for measuring transpiration and reverse flows. Two trees have two sensors each to assess the variability. Four volumetric soil moisture sensors are installed around each tree at distances 1 m and 2 m away from the tree trunk. An additional fifth soil moisture sensor is installed in soil depths exceeding 20-cm depth. Four throughfall rain gauges were installed randomly around each tree to compute interception losses. Stemflow is measured by connecting an opened surface plastic tube collar at 1.6 m height around each tree trunk. The trunk surface gaps were filled with silicon glue in order to avoid any stemflow losses. The plastic collar is connected to a sealed surface rain gauge. A weather station monitors all meteorological variables on an hourly basis. Results showed a maximum sap flow volume of 77.9 L/d, from November to January. The sensors also measured a maximum negative flow of 7.9 L

  12. [Dynamic Characteristics of Base Cations During Wet Deposition in Evergreen Broad-leaf Forest Ecosystem].

    Science.gov (United States)

    An, Si-wei; Sun, Tao; Ma, Ming; Wang, Ding-yong

    2015-12-01

    Based on field tests and laboratory experiments, effects of precipitation, throughfall, litterfall, and groundwater runoff of the ever-green broad-leaf forest on the dynamic characteristics of base cations in Simian Mountain were investigated from September 2012 to August 2013. The results showed that the rainfall of Simian Mountain was apparently acidic, with average pH of 4.90 and maximum pH of 5.14. The soil and canopies could increase pH of precipitation, with soils having the maximum increment, followed by the forest canopy. Forest canopy only had the function of interception on Na⁺. And precipitation could leach out Ca2⁺, Mg2⁺ and K⁺ of the canopies. Moreover, the degradation of litter was probably the main reason for the increase of base cations concentrations in the surface litter water. The litter water leached Ca2⁺, Mg2⁺ and Na⁺ of the forest soil through downward infiltration. The total retention rates of Ca²⁺, Mg²⁺, Na⁺ and K⁺ were 33.82%, -7.06%, 74.36% and 42.87%, respectively. Ca²⁺, Na⁺, K⁺ were found to be reserved in the forest ecosystem, and the highest interception rate was found for Na⁺.

  13. Seasonal dynamics of soil CO2 emission in the boreal forests in Central Siberia

    Science.gov (United States)

    Makhnykina, A. V.; Prokishkin, A. S.; Zyryanov, V.; Verkhovets, S. V.

    2016-12-01

    A large amount of carbon in soil is released to the atmosphere through soil respiration, which is the main pathway of transferring carbon from terrestrial ecosystems (Comstedt et al., 2011). Considering that boreal forests is a large terrestrial sink (Tans et al., 1990) and represent approximately 11 % of the Earth's total land area (Gower et al., 2001), even a small change in soil respiration could significantly intensify - or mitigate - current atmospheric increases of CO2, with potential feedbacks to climate change. The objectives of the present study are: (a) to study the dynamic of CO2emission from the soil surface during summer season (from May to October); (b) to identify the reaction of soil respiration to different amount of precipitation as the main limiting factor in the region. The research was carried out in the pine forests in Central Siberia (60°N, 90°E), Russia. Sample plots were represented by the lichen pine forest, moss pine forest, mixed forest and anthropogenic destroyed area. We used the automated soil CO2 flux system based on the infrared gas analyzer LI-8100 for measuring the soil efflux. Soil temperature was measured with Soil Temperature Probe Type E in three depths 5, 10, 15 cm. Volumetric soil moisture was measured with Theta Probe Model ML2. The presence and type of ground cover substantially affects the value of soil respiration fluxes. The carbon dioxide emission from the soil surface averaged was 5.4 ±2.3 μmol CO2 m-2 s-1. The destroyed area without plant cover demonstrated the lowest soil respiration (0.1-5.6 μmol CO2 m-2 s-1). The lowest soil respiration among forested areas was observed in the feathermoss pine forest. The lichen pine forest soil respiration was characterized by averages values. The maximum soil respiration values and seasonal fluctuations were obtained in the mixed forest (2.3-29.3 μmol CO2 m-2 s-1). The analysis of relation between soil CO2 efflux and amount of precipitation showed that the site without any

  14. Carbon stocks and dynamics at different successional stages in an Afromontane tropical forest

    Science.gov (United States)

    Nyirambangutse, Brigitte; Zibera, Etienne; Uwizeye, Félicien K.; Nsabimana, Donat; Bizuru, Elias; Pleijel, Håkan; Uddling, Johan; Wallin, Göran

    2017-03-01

    As a result of different types of disturbance, forests are a mixture of stands at different stages of ecological succession. Successional stage is likely to influence forest productivity and carbon storage, linking the degree of forest disturbance to the global carbon cycle and climate. Although tropical montane forests are an important part of tropical forest ecosystems (ca. 8 %, elevation > 1000 m a.s.l.), there are still significant knowledge gaps regarding the carbon dynamics and stocks of these forests, and how these differ between early (ES) and late successional (LS) stages. This study examines the carbon (C) stock, relative growth rate (RGR) and net primary production (NPP) of ES and LS forest stands in an Afromontane tropical rainforest using data from inventories of quantitatively important ecosystem compartments in fifteen 0.5 ha plots in Nyungwe National Park in Rwanda. The total C stock was 35 % larger in LS compared to ES plots due to significantly larger above-ground biomass (AGB; 185 and 76 Mg C ha-1 in LS and ES plots), while the soil and root C stock (down to 45 cm depth in the mineral soil) did not significantly differ between the two successional stages (178 and 204 Mg C ha-1 in LS and ES plots). The main reasons for the difference in AGB were that ES trees had significantly lower stature and wood density compared to LS trees. However, ES and LS stands had similar total NPP (canopy, wood and roots of all plots ˜ 9.4 Mg C ha-1) due to counterbalancing effects of differences in AGB (higher in LS stands) and RGR (higher in ES stands). The AGB in the LS plots was considerably higher than the average value reported for old-growth tropical montane forest of south-east Asia and Central and South America at similar elevations and temperatures, and of the same magnitude as in tropical lowland forest of these regions. The results of this study highlight the importance of accounting for disturbance regimes and differences in wood density and allometry of

  15. Selection and quality assessment of Landsat data for the North American forest dynamics forest history maps of the US

    Science.gov (United States)

    Schleeweis, Karen; Goward, Samuel N.; Huang, Chengquan; Dwyer, John L.; Dungan, Jennifer L.; Lindsey, Mary A.; Michaelis, Andrew; Rishmawi, Khaldoun; Masek, Jeffery G.

    2016-01-01

    Using the NASA Earth Exchange platform, the North American Forest Dynamics (NAFD) project mapped forest history wall-to-wall, annually for the contiguous US (1986–2010) using the Vegetation Change Tracker algorithm. As with any effort to identify real changes in remotely sensed time-series, data gaps, shifts in seasonality, misregistration, inconsistent radiometry and cloud contamination can be sources of error. We discuss the NAFD image selection and processing stream (NISPS) that was designed to minimize these sources of error. The NISPS image quality assessments highlighted issues with the Landsat archive and metadata including inadequate georegistration, unreliability of the pre-2009 L5 cloud cover assessments algorithm, missing growing-season imagery and paucity of clear views. Assessment maps of Landsat 5–7 image quantities and qualities are presented that offer novel perspectives on the growing-season archive considered for this study. Over 150,000+ Landsat images were considered for the NAFD project. Optimally, one high quality cloud-free image in each year or a total of 12,152 images would be used. However, to accommodate data gaps and cloud/shadow contamination 23,338 images were needed. In 220 specific path-row image years no acceptable images were found resulting in data gaps in the annual national map products.

  16. Seasonal estimates of riparian evapotranspiration using remote and in situ measurements

    Science.gov (United States)

    Goodrich, D.C.; Scott, R.; Qi, J.; Goff, B.; Unkrich, C.L.; Moran, M.S.; Williams, D.; Schaeffer, S.; Snyder, K.; MacNish, R.; Maddock, T.; Pool, D.; Chehbouni, A.; Cooper, D.I.; Eichinger, W.E.; Shuttleworth, W.J.; Kerr, Y.; Marsett, R.; Ni, W.

    2000-01-01

    In many semi-arid basins during extended periods when surface snowmelt or storm runoff is absent, groundwater constitutes the primary water source for human habitation, agriculture and riparian ecosystems. Utilizing regional groundwater models in the management of these water resources requires accurate estimates of basin boundary conditions. A critical groundwater boundary condition that is closely coupled to atmospheric processes and is typically known with little certainty is seasonal riparian evapotranspiration ET). This quantity can often be a significant factor in the basin water balance in semi-arid regions yet is very difficult to estimate over a large area. Better understanding and quantification of seasonal, large-area riparian ET is a primary objective of the Semi-Arid Land-Surface-Atmosphere (SALSA) Program. To address this objective, a series of interdisciplinary experimental Campaigns were conducted in 1997 in the San Pedro Basin in southeastern Arizona. The riparian system in this basin is primarily made up of three vegetation communities: mesquite (Prosopis velutina), sacaton grasses (Sporobolus wrightii), and a cottonwood (Populus fremontii)/willow (Salix goodingii) forest gallery. Micrometeorological measurement techniques were used to estimate ET from the mesquite and grasses. These techniques could not be utilized to estimate fluxes from the cottonwood/willow (C/W) forest gallery due to the height (20-30 m) and non-uniform linear nature of the forest gallery. Short-term (2-4 days) sap flux measurements were made to estimate canopy transpiration over several periods of the riparian growing season. Simultaneous remote sensing measurements were used to spatially extrapolate tree and stand measurements. Scaled C/W stand level sap flux estimates were utilized to calibrate a Penman-Monteith model to enable temporal extrapolation between Synoptic measurement periods. With this model and set of measurements, seasonal riparian vegetation water use

  17. Divergent carbon dynamics under climate change in forests with diverse soils, tree species, and land use histories

    Science.gov (United States)

    Robert M. Scheller; Alec M. Kretchun; Steve Van Tuyl; Kenneth L. Clark; Melissa S. Lucash; John Hom

    2012-01-01

    Accounting for both climate change and natural disturbances—which typically result in greenhouse gas emissions—is necessary to begin managing forest carbon sequestration. Gaining a complete understanding of forest carbon dynamics is, however, challenging in systems characterized by historic over-utilization, diverse soils and tree species, and...

  18. How do riparian woody seedlings survive seasonal drought?

    Science.gov (United States)

    Stella, John C; Battles, John J

    2010-11-01

    In semi-arid regions, a major population limitation for riparian trees is seedling desiccation during the dry season that follows annual spring floods. We investigated the stress response of first-year pioneer riparian seedlings to experimental water table declines (0, 1 and 3 cm day(-1)), focusing on the three dominant cottonwood and willows (family Salicaceae) in California's San Joaquin Basin. We analyzed growth and belowground allocation response to water stress, and used logistic regression to determine if these traits had an influence on individual survival. The models indicate that high root growth (>3 mm day(-1)) and low shoot:root ratios (water-use efficiency for surviving water stress. Both S. gooddingii and sandbar willow (S. exigua) reduced leaf size from controls, whereas Fremont cottonwood (Populus fremontii) sustained a 29% reduction in specific leaf area (from 13.4 to 9.6 m(2) kg(-1)). The functional responses exhibited by Goodding's willow, the more drought-tolerant species, may play a role in its greater relative abundance in dry regions such as the San Joaquin Basin. This study highlights the potential for a shift in riparian forest composition. Under a future drier climate regime or under reduced regulated river flows, our results suggest that willow establishment will be favored over cottonwood.

  19. Comparison of leaf-on and leaf-off ALS data for mapping riparian tree species

    Science.gov (United States)

    Laslier, Marianne; Ba, Antoine; Hubert-Moy, Laurence; Dufour, Simon

    2017-10-01

    Forest species composition is a fundamental indicator of forest study and management. However, describing forest species composition at large scales and of highly diverse populations remains an issue for which remote sensing can provide significant contribution, in particular, Airborne Laser Scanning (ALS) data. Riparian corridors are good examples of highly valuable ecosystems, with high species richness and large surface areas that can be time consuming and expensive to monitor with in situ measurements. Remote sensing could be useful to study them, but few studies have focused on monitoring riparian tree species using ALS data. This study aimed to determine which metrics derived from ALS data are best suited to identify and map riparian tree species. We acquired very high density leaf-on and leaf-off ALS data along the Sélune River (France). In addition, we inventoried eight main riparian deciduous tree species along the study site. After manual segmentation of the inventoried trees, we extracted 68 morphological and structural metrics from both leaf-on and leaf-off ALS point clouds. Some of these metrics were then selected using Sequential Forward Selection (SFS) algorithm. Support Vector Machine (SVM) classification results showed good accuracy with 7 metrics (0.77). Both leaf-on and leafoff metrics were kept as important metrics for distinguishing tree species. Results demonstrate the ability of 3D information derived from high density ALS data to identify riparian tree species using external and internal structural metrics. They also highlight the complementarity of leaf-on and leaf-off Lidar data for distinguishing riparian tree species.

  20. A comparison of nutrient dynamics in forest ecosystems along with the Warmth Index Gradient

    International Nuclear Information System (INIS)

    Iwatsubo, Goro; Li Changhua; Katagiri, Shigeo.

    1993-01-01

    Nutrient elements contained in litter fall flux, that of uptake flux and turnover rate had generally tended to increase with the increase in the Warmth Index, while the amount of nutrient in the A 0 horizon and nutrient use efficiency did not. However, it is suggested that topographic and climatic aridity, and the amount of available and exchangeable phosphorus, calcium and magnesium greatly affect the nutrient dynamics in a each forest ecosystem as the Warmth Index increases. (J.P.N.)

  1. Social-ecological dynamics of the small scale fisheries in Sundarban Mangrove Forest, Bangladesh

    OpenAIRE

    Mohammad Mojibul Hoque Mozumder; Md. Mostafa Shamsuzzaman; Md. Rashed-Un-Nabi; Ehsanul Karim

    2018-01-01

    The Sundarban Mangrove Forest (SMF) is an intricate ecosystem containing the most varied and profuse natural resources of Bangladesh. This study presents empirical research, based on primary and secondary data, regarding the social-ecological system (SES), social-ecological dynamics, different stakeholders and relevant management policies of small-scale or artisanal fisheries such as the SMF; showing how, despite extensive diversification, the livelihood activities of the artisanal fishers in...

  2. Dynamic Minimum Spanning Forest with Subpolynomial Worst-case Update Time

    DEFF Research Database (Denmark)

    Nanongkai, Danupon; Saranurak, Thatchaphol; Wulff-Nilsen, Christian

    2017-01-01

    Abstract: We present a Las Vegas algorithm for dynamically maintaining a minimum spanning forest of an nnode graph undergoing edge insertions and deletions. Our algorithm guarantees an O(no(1)) worst-case update time with high probability. This significantly improves the two recent Las Vegas algo...... the previous approach in [2], [3] which is based on Frederickson's 2-dimensional topology tree [6] and illustrates a new application to this old technique....

  3. Aerosol dynamics within and above forest in relation to turbulent transport and dry deposition

    OpenAIRE

    Rannik, Üllar; Zhou, Luxi; Zhou, Putian; Gierens, Rosa; Mammarella, Ivan; Sogachev, Andrey; Boy, Michael

    2016-01-01

    A 1-D atmospheric boundary layer (ABL) model coupled with a detailed atmospheric chemistry and aerosol dynamical model, the model SOSAA, was used to predict the ABL and detailed aerosol population (characterized by the number size distribution) time evolution. The model was applied over a period of 10 days in May 2013 to a pine forest site in southern Finland. The period was characterized by frequent new particle formation events and simultaneous intensive aerosol transforma...

  4. Microbial activity and the dynamics of ecosystem processes in forest soils

    Czech Academy of Sciences Publication Activity Database

    Baldrian, Petr

    2017-01-01

    Roč. 37, č. 3 (2017), s. 128-134 ISSN 1369-5274 R&D Projects: GA ČR GA13-06763S; GA ČR(CZ) GA16-08916S; GA MŠk(CZ) LD15086; GA MŠk(CZ) LM2015055 Institutional support: RVO:61388971 Keywords : ECTOMYCORRHIZAL FUNGAL LITTER * TEMPERATE OAK FOREST * SEASONAL DYNAMICS Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 6.635, year: 2016

  5. Long-term Seedling Dynamics of Tree Species in a Subtropical Rain Forest, Taiwan

    Directory of Open Access Journals (Sweden)

    Chia-Hao Chang-Yang

    2013-03-01

    Full Text Available Knowledge of demographical rates at seedling stage is critical for understanding forest composition and dynamics. We monitored the seedling dynamics of tree species in a subtropical rain forest in Fushan, northern Taiwan (24°45’ N, 121°35’ E during an 8-yr period (2003–2010. There were great temporal fluctuations in the seedling density, which might be largely driven by the pulses of seedling recruitment. Interspecific variation in the seedling abundance, however, was not related to the reproductive adult abundance. Previous studies showed that frequent typhoon disturbances contributed to the high canopy openness and high understory light availability at Fushan, which might benefit tree regeneration. But our results do not support this idea. Most of the newly recruited seedlings died within six months and only grew 1.55 ± 0.20 cm per year, which might be suppressed by the dense understory vegetation. Our results suggested that the majority of tree species in Fushan were recruitment limited, which might have important consequences for species coexistence. High temporal variability in recruitment density and low growth rates of seedlings emphasize the importance of long-term studies to our understandings of forest dynamics.

  6. Groundwater management institutions to protect riparian habitat

    Science.gov (United States)

    Orr, Patricia; Colby, Bonnie

    2004-12-01

    Groundwater pumping affects riparian habitat when it causes the water table to drop beyond the reach of riparian plants. Riparian habitat provides services that are not directly traded in markets, as is the case with many environmental amenities. There is no direct market where one may buy or sell the mix of services provided by a riparian corridor. The objective of this article is to review groundwater management mechanisms and assess their strengths and weaknesses for preserving the ecological integrity of riparian areas threatened by groundwater pumping. Policy instruments available to those concerned with the effects of groundwater pumping on riparian areas fall into three broad categories: (1) command and control (CAC), (2) incentive-based economic instruments, and (3) cooperative/suasive strategies. The case of the San Pedro River illustrates multiple and overlapping strategies applied in an ongoing attempt to reverse accumulating damage to a riparian ecosystem. Policy makers in the United States can choose among a broad menu of policy options to protect riparian habitat from groundwater pumping. They can capitalize on the clarity of command-and-control strategies, the flexibility and less obtrusive nature of incentive-based economic strategies, and the benefits that collaborative efforts can bring in the form of mutual consideration. While collaborative problem solving and market-based instruments are important policy tools, experience indicates that a well-formulated regulatory structure to limit regional groundwater pumping is an essential component of an effective riparian protection strategy.

  7. Increased drought impacts on temperate rainforests from southern South America: results of a process-based, dynamic forest model.

    Directory of Open Access Journals (Sweden)

    Alvaro G Gutiérrez

    Full Text Available Increased droughts due to regional shifts in temperature and rainfall regimes are likely to affect forests in temperate regions in the coming decades. To assess their consequences for forest dynamics, we need predictive tools that couple hydrologic processes, soil moisture dynamics and plant productivity. Here, we developed and tested a dynamic forest model that predicts the hydrologic balance of North Patagonian rainforests on Chiloé Island, in temperate South America (42°S. The model incorporates the dynamic linkages between changing rainfall regimes, soil moisture and individual tree growth. Declining rainfall, as predicted for the study area, should mean up to 50% less summer rain by year 2100. We analysed forest responses to increased drought using the model proposed focusing on changes in evapotranspiration, soil moisture and forest structure (above-ground biomass and basal area. We compared the responses of a young stand (YS, ca. 60 years-old and an old-growth forest (OG, >500 years-old in the same area. Based on detailed field measurements of water fluxes, the model provides a reliable account of the hydrologic balance of these evergreen, broad-leaved rainforests. We found higher evapotranspiration in OG than YS under current climate. Increasing drought predicted for this century can reduce evapotranspiration by 15% in the OG compared to current values. Drier climate will alter forest structure, leading to decreases in above ground biomass by 27% of the current value in OG. The model presented here can be used to assess the potential impacts of climate change on forest hydrology and other threats of global change on future forests such as fragmentation, introduction of exotic tree species, and changes in fire regimes. Our study expands the applicability of forest dynamics models in remote and hitherto overlooked regions of the world, such as southern temperate rainforests.

  8. Increased drought impacts on temperate rainforests from southern South America: results of a process-based, dynamic forest model.

    Science.gov (United States)

    Gutiérrez, Alvaro G; Armesto, Juan J; Díaz, M Francisca; Huth, Andreas

    2014-01-01

    Increased droughts due to regional shifts in temperature and rainfall regimes are likely to affect forests in temperate regions in the coming decades. To assess their consequences for forest dynamics, we need predictive tools that couple hydrologic processes, soil moisture dynamics and plant productivity. Here, we developed and tested a dynamic forest model that predicts the hydrologic balance of North Patagonian rainforests on Chiloé Island, in temperate South America (42°S). The model incorporates the dynamic linkages between changing rainfall regimes, soil moisture and individual tree growth. Declining rainfall, as predicted for the study area, should mean up to 50% less summer rain by year 2100. We analysed forest responses to increased drought using the model proposed focusing on changes in evapotranspiration, soil moisture and forest structure (above-ground biomass and basal area). We compared the responses of a young stand (YS, ca. 60 years-old) and an old-growth forest (OG, >500 years-old) in the same area. Based on detailed field measurements of water fluxes, the model provides a reliable account of the hydrologic balance of these evergreen, broad-leaved rainforests. We found higher evapotranspiration in OG than YS under current climate. Increasing drought predicted for this century can reduce evapotranspiration by 15% in the OG compared to current values. Drier climate will alter forest structure, leading to decreases in above ground biomass by 27% of the current value in OG. The model presented here can be used to assess the potential impacts of climate change on forest hydrology and other threats of global change on future forests such as fragmentation, introduction of exotic tree species, and changes in fire regimes. Our study expands the applicability of forest dynamics models in remote and hitherto overlooked regions of the world, such as southern temperate rainforests.

  9. Carbon and nitrogen dynamics of soil and litter along an altitudinal gradient in Atlantic Forest

    Science.gov (United States)

    Piccolo, M. D.; Martins, S. C.; Camargo, P. B.; Carmo, J. B.; Sousa Neto, E.; Martinelli, L. A.

    2008-12-01

    The Ombrophylus Dense Forest or Atlantic Forest is the second most important Biome in extension of Brazil, and it is considered a hot-spot in terms of biodiversity. It is localized in Brazilian Coast, and it covered originally 1.2 million km2, but currently only 8% of the original forest remains. The study was carried out in Sao Paulo State, Brazil (23° 24' S and 45° 11' W). The studied areas were: Restinga Vegetation (RV), 5 m above sea level; Low Altitude Ombrophylus Dense Forest (LAODF), 100 m asl; Submontane Ombrophylus Dense Forest (SODF), 600m asl and; Montane Ombrophylus Dense Forest (MODF), 1000 m asl. The aim of this study was to evaluate the effect of altitudinal gradient, with specific phytophysiognomies, on C and N dynamics in the soil and litter at Atlantic Forest. A sampling area of 1 ha was subdivided in contiguous sub- parcels (10 x 10 m). The forest floor litter accumulated (0.06 m2) was collected monthly (n=60), during 12 months, in each phytophysiognomies. Soils samples (0-0.05m depth) were collected (n=32) from square regular grids, 30 m away from each other. Changes in litter contents of C and N were not detected along the altitudinal gradient, and the values observed were 400 and 15g kg-1 for C and N, respectively. Litter ä13C values did not change significantly with the altitudinal gradient and were represented by C3 plants values. The C and N stocks were high in the clay soils (LAODF, SODF and MODF) when compared to sandy soil (RV). The soil C stocks (24 to 30 Mg ha-1) were similar among the altitudinal gradients, except RV (16 Mg ha-1). The areas of elevated altitude (MODF and SODF) showed high N stocks (2.3 Mg ha-1), followed by LAODF (1.8Mg ha-1) and RV (0.9Mg ha-1). In all altitudes there was 13C enrichment with soil depth, and it can be explained by the different fractions of the organic matter distributed along the soil profile, and also due the effect of the isotopic dilution between the forest floor litter and the soil.

  10. A Black Swan and Sub-continental Scale Dynamics in Humid, Late-Holocene Broadleaf Forests

    Science.gov (United States)

    Pederson, N.; Dyer, J.; McEwan, R.; Hessl, A. E.; Mock, C. J.; Orwig, D.; Rieder, H. E.; Cook, B. I.

    2012-12-01

    In humid regions with dense broadleaf-dominated forests where gap-dynamics is the prevailing disturbance regime, paleoecological evidence shows regional-scale changes in forest composition associated with climatic change. To investigate the potential for regional events in late-Holocene forests, we use tree-ring data from 76 populations covering 840,000 km2 and 5.3k tree recruitment dates spanning 1.4 million km2 in the eastern US to investigate the occurrence of simultaneous forest dynamics across a humid region. We compare regional forest dynamics with an independent set of annually-resolved tree ring record of hydroclimate to examine whether climate dynamics might drive forest dynamics in this humid region. In forests where light availability is an important limitation for tree recruitment, we document a pulse of tree recruitment during the mid- to late-1600s across the eastern US. This pulse, which can be inferred as large-scale canopy opening, occurred during an era that multiple proxies indicate as extended drought between two intense pluvial. Principal component analysis of the 76 populations indicates a step-change increase in average ring width during the late-1770s resembling a potential canopy accession event over 42,800 km2 of the southeastern US. Growth-release analysis of populations loading strongly on this eigenvector indicates severe canopy disturbance from 1775-1779 that peaked in 1776. The 1776 event follows a period with extended droughts and severe large-scale frost event. We hypothesize these climatic events lead to elevated tree mortality in the late-1770s and canopy accession for understory trees. Superposed epoch analysis reveals that spikes of elevated canopy disturbance from 1685-1850 CE are significantly associated with drought. Extreme value theory statistics indicates the 1776 event lies beyond the 99.9 quantile and nearly 7 sigmas above the 1685-1850 mean rate of disturbance. The time-series of canopy disturbance from 1685-1850 is so

  11. Riparian Habitat Management for Mammals on Corps of Engineers Projects

    National Research Council Canada - National Science Library

    Martin, Chester

    2002-01-01

    .... This note provides an overview of the importance of riparian ecosystems to mammals, discusses regional variation in mammal communities characteristic of riparian zones, identifies potential impacts...

  12. Long-Term Forest Dynamics and Land-Use Abandonment in the Mediterranean Mountains, Corsica, France

    Directory of Open Access Journals (Sweden)

    Almudena San Roman Sanz

    2013-06-01

    Full Text Available Human practices have had an impact on Mediterranean ecosystems for millennia, particularly through agricultural and pastoral activities. Since the mid-19th century, land-use abandonment has led to the expansion of shrubland and forest, especially in the mountainous areas of the northern Mediterranean basin. Knowledge of these factors is vital to understanding present forest patterns and predicting future forest dynamics in the Mediterranean mountains. We aimed to analyze and understand how land-use abandonment affected spatial modifications of landscapes in two study areas, 44,000 ha and 60,000 ha, located on the island of Corsica, France, representing a typical Mediterranean environment with chestnut forests. Our approach used land-cover archive documents from 1774, 1913, 1975, and 2000, and human population history, 1770 to present day, to describe landscape patterns following land-use abandonment. This research showed that dramatic changes in landscape at the two study areas were caused by the suspension of human influence and the interruption of traditional farming practices. Over the study period, both study sites showed significant reforestation of shrubland and cultivated areas marked by the presence of Quercus ilex forests (+3.40% yr-1 between 1975 and 2000 and by Pinus pinaster (+3.00% yr-1 between 1975 and 2000 at one study site that had experienced heavy rural exodus. At the same time, areas containing chestnut forests decreased by 50% between 1774 and 2000 (-0.09% yr-1 between 1774 and 1975 and -1.42% yr-1 between 1975 and 2000. Shrubland expansion remained limited at both study sites. Our study highlights the value of small-scale approaches for understanding the ecological consequences of land-use abandonment and present and future land-management decisions. Discussion concludes on the importance of working with long-term series for studies on resilience in social-ecological systems and on the consequences in terms of provision of

  13. Incorporating microbial dormancy dynamics into soil decomposition models to improve quantification of soil carbon dynamics of northern temperate forests

    Energy Technology Data Exchange (ETDEWEB)

    He, Yujie [Purdue Univ., West Lafayette, IN (United States). Dept. of Earth, Atmospheric, and Planetary Sciences; Yang, Jinyan [Univ. of Georgia, Athens, GA (United States). Warnell School of Forestry and Natural Resources; Northeast Forestry Univ., Harbin (China). Center for Ecological Research; Zhuang, Qianlai [Purdue Univ., West Lafayette, IN (United States). Dept. of Earth, Atmospheric, and Planetary Sciences; Purdue Univ., West Lafayette, IN (United States). Dept. of Agronomy; Harden, Jennifer W. [U.S. Geological Survey, Menlo Park, CA (United States); McGuire, Anthony D. [Alaska Cooperative Fish and Wildlife Research Unit, U.S. Geological Survey, Univ. of Alaska, Fairbanks, AK (United States). U.S. Geological Survey, Alaska Cooperative Fish and Wildlife Research Unit; Liu, Yaling [Purdue Univ., West Lafayette, IN (United States). Dept. of Earth, Atmospheric, and Planetary Sciences; Wang, Gangsheng [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Climate Change Science Inst. and Environmental Sciences Division; Gu, Lianhong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Environmental Sciences Division

    2015-11-20

    Soil carbon dynamics of terrestrial ecosystems play a significant role in the global carbon cycle. Microbial-based decomposition models have seen much growth recently for quantifying this role, yet dormancy as a common strategy used by microorganisms has not usually been represented and tested in these models against field observations. Here in this study we developed an explicit microbial-enzyme decomposition model and examined model performance with and without representation of microbial dormancy at six temperate forest sites of different forest types. We then extrapolated the model to global temperate forest ecosystems to investigate biogeochemical controls on soil heterotrophic respiration and microbial dormancy dynamics at different temporal-spatial scales. The dormancy model consistently produced better match with field-observed heterotrophic soil CO2 efflux (RH) than the no dormancy model. Our regional modeling results further indicated that models with dormancy were able to produce more realistic magnitude of microbial biomass (<2% of soil organic carbon) and soil RH (7.5 ± 2.4 PgCyr-1). Spatial correlation analysis showed that soil organic carbon content was the dominating factor (correlation coefficient = 0.4-0.6) in the simulated spatial pattern of soil RH with both models. In contrast to strong temporal and local controls of soil temperature and moisture on microbial dormancy, our modeling results showed that soil carbon-to-nitrogen ratio (C:N) was a major regulating factor at regional scales (correlation coefficient = -0.43 to -0.58), indicating scale-dependent biogeochemical controls on microbial dynamics. Our findings suggest that incorporating microbial dormancy could improve the realism of microbial-based decomposition models and enhance the integration of soil experiments and mechanistically based modeling.

  14. Incorporating microbial dormancy dynamics into soil decomposition models to improve quantification of soil carbon dynamics of northern temperate forests

    Science.gov (United States)

    He, Yujie; Yang, Jinyan; Zhuang, Qianlai; Harden, Jennifer W.; McGuire, A. David; Liu, Yaling; Wang, Gangsheng; Gu, Lianhong

    2015-01-01

    Soil carbon dynamics of terrestrial ecosystems play a significant role in the global carbon cycle. Microbial-based decomposition models have seen much growth recently for quantifying this role, yet dormancy as a common strategy used by microorganisms has not usually been represented and tested in these models against field observations. Here we developed an explicit microbial-enzyme decomposition model and examined model performance with and without representation of microbial dormancy at six temperate forest sites of different forest types. We then extrapolated the model to global temperate forest ecosystems to investigate biogeochemical controls on soil heterotrophic respiration and microbial dormancy dynamics at different temporal-spatial scales. The dormancy model consistently produced better match with field-observed heterotrophic soil CO2 efflux (RH) than the no dormancy model. Our regional modeling results further indicated that models with dormancy were able to produce more realistic magnitude of microbial biomass (analysis showed that soil organic carbon content was the dominating factor (correlation coefficient = 0.4–0.6) in the simulated spatial pattern of soil RHwith both models. In contrast to strong temporal and local controls of soil temperature and moisture on microbial dormancy, our modeling results showed that soil carbon-to-nitrogen ratio (C:N) was a major regulating factor at regional scales (correlation coefficient = −0.43 to −0.58), indicating scale-dependent biogeochemical controls on microbial dynamics. Our findings suggest that incorporating microbial dormancy could improve the realism of microbial-based decomposition models and enhance the integration of soil experiments and mechanistically based modeling.

  15. Similar below-ground carbon cycling dynamics but contrasting modes of nitrogen cycling between arbuscular mycorrhizal and ectomycorrhizal forests.

    Science.gov (United States)

    Lin, Guigang; McCormack, M Luke; Ma, Chengen; Guo, Dali

    2017-02-01

    Compared with ectomycorrhizal (ECM) forests, arbuscular mycorrhizal (AM) forests are hypothesized to have higher carbon (C) cycling rates and a more open nitrogen (N) cycle. To test this hypothesis, we synthesized 645 observations, including 22 variables related to below-ground C and N dynamics from 100 sites, where AM and ECM forests co-occurred at the same site. Leaf litter quality was lower in ECM than in AM trees, leading to greater forest floor C stocks in ECM forests. By contrast, AM forests had significantly higher mineral soil C concentrations, and this result was strongly mediated by plant traits and climate. No significant differences were found between AM and ECM forests in C fluxes and labile C concentrations. Furthermore, inorganic N concentrations, net N mineralization and nitrification rates were all higher in AM than in ECM forests, indicating 'mineral' N economy in AM but 'organic' N economy in ECM trees. AM and ECM forests show systematic differences in mineral vs organic N cycling, and thus mycorrhizal type may be useful in predicting how different tree species respond to multiple environmental change factors. By contrast, mycorrhizal type alone cannot reliably predict below-ground C dynamics without considering plant traits and climate. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  16. Riparian vegetation structure under desertification scenarios

    Science.gov (United States)

    Rosário Fernandes, M.; Segurado, Pedro; Jauch, Eduardo; Ferreira, M. Teresa

    2015-04-01

    Riparian areas are responsible for many ecological and ecosystems services, including the filtering function, that are considered crucial to the preservation of water quality and social benefits. The main goal of this study is to quantify and understand the riparian variability under desertification scenario(s) and identify the optimal riparian indicators for water scarcity and droughts (WS&D), henceforth improving river basin management. This study was performed in the Iberian Tâmega basin, using riparian woody patches, mapped by visual interpretation on Google Earth imagery, along 130 Sampling Units of 250 m long river stretches. Eight riparian structural indicators, related with lateral dimension, weighted area and shape complexity of riparian patches were calculated using Patch Analyst extension for ArcGis 10. A set of 29 hydrological, climatic, and hydrogeomorphological variables were computed, by a water modelling system (MOHID), using monthly meteorological data between 2008 and 2014. Land-use classes were also calculated, in a 250m-buffer surrounding each sampling unit, using a classification based system on Corine Land Cover. Boosted Regression Trees identified Mean-width (MW) as the optimal riparian indicator for water scarcity and drought, followed by the Weighted Class Area (WCA) (classification accuracy =0.79 and 0.69 respectively). Average Flow and Strahler number were consistently selected, by all boosted models, as the most important explanatory variables. However, a combined effect of hidrogeomorphology and land-use can explain the high variability found in the riparian width mainly in Tâmega tributaries. Riparian patches are larger towards Tâmega river mouth although with lower shape complexity, probably related with more continuous and almost monospecific stands. Climatic, hydrological and land use scenarios, singly and combined, were used to quantify the riparian variability responding to these changes, and to assess the loss of riparian

  17. Carbon dynamics after forest harvest in Central Siberia: the ZOTTO footprint area

    Science.gov (United States)

    Panov, Alexey; Zrazhevskaya, Galina; Shibistova, Olga; Onuchin, Alexander; Heimann, Martin

    2013-04-01

    Temperate and boreal forests of the Northern Hemisphere have been recognized as important carbon sinks. Accurate calculation of forest carbon budget and estimation of the temporal variations of forest net carbon fluxes are important topics to elucidate the ''missing sink'' question and follow up the changing carbon dynamics in forests. In the frame of the ongoing Russian-German partner project the Zotino Tall Tower Observatory (ZOTTO; www.zottoproject.org) a unique international research platform for large-scale climatic observations is operational about 20 km west of the Yenisei river (60.8°N; 89.35°E). The data of the ongoing greenhouse gas and aerosol measurements at the tall tower are used in atmospheric inversions studies to infer the distribution of carbon sinks and sources over the whole Northern Eurasia. The tall tower footprint area estimates of carbon stocks and fluxes are highly demanded for bottom-up validation of inversion estimates. The ZOTTO site lies in a vast region of forests and wetlands, still relatively undisturbed by anthropogenic influences, but a moderate human impact on vegetation, represented mainly by logging activities, becomes essential. Therefore, accurate estimates of carbon pools in vegetation and soil following harvesting are essential to inversion studies for ZOTTO and critical to predictions of both local ecosystem sustainability and global C exchange with the atmosphere. We present our investigation of carbon dynamics after forest harvest in the tall tower footprint area (~1000 km2). The changes in C pools and annual sequestration were quantified among several clear-cut lichen pine (Pinus sylvestris Lamb.) stands representing various stages of secondary succession with a "space-for-time substitution" technique. When viewed as a chronosequence, these stands represent snapshots showing how the effects of logging may propagate through time. The study concluded that ecosystems during the first 15 yrs after forest harvest become C

  18. Using Landsat time series for characterizing forest disturbance dynamics in the coupled human and natural systems of Central Europe.

    Science.gov (United States)

    Senf, Cornelius; Pflugmacher, Dirk; Hostert, Patrick; Seidl, Rupert

    2017-08-01

    Remote sensing is a key information source for improving the spatiotemporal understanding of forest ecosystem dynamics. Yet, the mapping and attribution of forest change remains challenging, particularly in areas where a number of interacting disturbance agents simultaneously affect forest development. The forest ecosystems of Central Europe are coupled human and natural systems, with natural and human disturbances affecting forests both individually and in combination. To better understand the complex forest disturbance dynamics in such systems, we utilize 32-year Landsat time series to map forest disturbances in five sites across Austria, the Czech Republic, Germany, Poland, and Slovakia. All sites consisted of a National Park and the surrounding forests, reflecting three management zones of different levels of human influence (managed, protected, strictly protected). This allowed for a comparison of spectral, temporal, and spatial disturbance patterns across a gradient from natural to coupled human and natural disturbances. Disturbance maps achieved overall accuracies ranging from 81% to 93%. Disturbance patches were generally small, with 95% of the disturbances being smaller than 10 ha. Disturbance rates ranged from 0.29% yr -1 to 0.95% yr -1 , and differed substantially among management zones and study sites. Natural disturbances in strictly protected areas were longer in duration (median of 8 years) and slightly less variable in magnitude compared to human-dominated disturbances in managed forests (median duration of 1 year). However, temporal dynamics between natural and human-dominated disturbances showed strong synchrony, suggesting that disturbance peaks are driven by natural events affecting managed and unmanaged areas simultaneously. Our study demonstrates the potential of remote sensing for mapping forest disturbances in coupled human and natural systems, such as the forests of Central Europe. Yet, we also highlight the complexity of such systems in

  19. Woodland: dynamics of average diameters of coniferous tree stands of the principal forest types

    Directory of Open Access Journals (Sweden)

    R. A. Ziganshin

    2016-08-01

    Full Text Available The analysis of age dynamics of average diameters of deciduous tree stands of different forest types at Highland Khamar-Daban (natural woodland in South-East Baikal Lake region has been done. The aggregate data of average tree, the analysis of age dynamics of average diameters of a deciduous tree stands of stand diameters by age classes, as well as tree stand current periodic and overall average increment are presented and discussed in the paper. Forest management appraisal is done. The most representative forest types have been selected to be analyzed. There were nine of them including three Siberian stone pine Pinus sibirica Du Tour stands, three Siberian fir Abies sibirica Ledeb. stands, one Siberian spruce Picea obovata Ledeb. stand, and two dwarf Siberian pine Pinus pumila (Pallas Regel stands. The whole high-altitude range of mountain taiga has been evaluated. Mathematical and statistic indicators have been calculated for every forest type. Stone pine stands are the largest. Dynamics of mean diameters of forest stands have been examined by dominant species for every forest type. Quite a number of interesting facts have been elicited. Generally, all species have maximal values of periodic annual increment that is typical for young stands, but further decrease of increment is going on differently and connects to the different lifetime of wood species. It is curious that annual increment of the dwarf Siberian pine stands almost does not decrease with aging. As for mean annual increment, it is more stable than periodic annual increment. From the fifth age class (age of stand approaching maturity mean annual increment of cedar stands varies from 0.20 to 0.24 cm per year; from 0.12–0.15 to 0.18–0.21 cm per year – in fir stands; from 0.18 to 0.24 cm per year – in spruce stands; and from 0.02–0.03 to 0.05–0.06 cm per year – in draft pine stands. Mean annual increment of dwarf Siberian pine increases with aging and increment of other

  20. Implications of the spatial dynamics of fire spread for the bistability of savanna and forest.

    Science.gov (United States)

    Schertzer, E; Staver, A C; Levin, S A

    2015-01-01

    The role of fire in expanding the global distribution of savanna is well recognized. Empirical observations and modeling suggest that fire spread has a threshold response to fuel-layer continuity, which sets up a positive feedback that maintains savanna-forest bistability. However, modeling has so far failed to examine fire spread as a spatial process that interacts with vegetation. Here, we use simple, well-supported assumptions about fire spread as an infection process and its effects on trees to ask whether spatial dynamics qualitatively change the potential for savanna-forest bistability. We show that the spatial effects of fire spread are the fundamental reason that bistability is possible: because fire spread is an infection process, it exhibits a threshold response to fuel continuity followed by a rapid increase in fire size. Other ecological processes affecting fire spread may also contribute including temporal variability in demography or fire spread. Finally, including the potential for spatial aggregation increases the potential both for savanna-forest bistability and for savanna and forest to coexist in a landscape mosaic.

  1. A walk on the wild side: Disturbance dynamics and the conservation and management of European mountain forest ecosystems.

    Science.gov (United States)

    Kulakowski, Dominik; Seidl, Rupert; Holeksa, Jan; Kuuluvainen, Timo; Nagel, Thomas A; Panayotov, Momchil; Svoboda, Miroslav; Thorn, Simon; Vacchiano, Giorgio; Whitlock, Cathy; Wohlgemuth, Thomas; Bebi, Peter

    2017-03-15

    Mountain forests are among the most important ecosystems in Europe as they support numerous ecological, hydrological, climatic, social, and economic functions. They are unique relatively natural ecosystems consisting of long-lived species in an otherwise densely populated human landscape. Despite this, centuries of intensive forest management in many of these forests have eclipsed evidence of natural processes, especially the role of disturbances in long-term forest dynamics. Recent trends of land abandonment and establishment of protected forests have coincided with a growing interest in managing forests in more natural states. At the same time, the importance of past disturbances highlighted in an emerging body of literature, and recent increasing disturbances due to climate change are challenging long-held views of dynamics in these ecosystems. Here, we synthesize aspects of this Special Issue on the ecology of mountain forest ecosystems in Europe in the context of broader discussions in the field, to present a new perspective on these ecosystems and their natural disturbance regimes. Most mountain forests in Europe, for which long-term data are available, show a strong and long-term effect of not only human land use but also of natural disturbances that vary by orders of magnitude in size and frequency. Although these disturbances may kill many trees, the forests themselves have not been threatened. The relative importance of natural disturbances, land use, and climate change for ecosystem dynamics varies across space and time. Across the continent, changing climate and land use are altering forest cover, forest structure, tree demography, and natural disturbances, including fires, insect outbreaks, avalanches, and wind disturbances. Projected continued increases in forest area and biomass along with continued warming are likely to further promote forest disturbances. Episodic disturbances may foster ecosystem adaptation to the effects of ongoing and future

  2. Evapotranspiration Calculation on the Basis of the Riparian Zone Water Balance

    Directory of Open Access Journals (Sweden)

    SZILÁGYI, József

    2008-01-01

    Full Text Available Riparian forests have a strong influence on groundwater levels and groundwater sustainedstream baseflow. An empirical and a hydraulic version of a new method were developed to calculateevapotranspiration values from riparian zone groundwater levels. The new technique was tested on thehydrometeorological data set of the Hidegvíz Valley (located in Sopron Hills at the eastern foothills ofthe Alps experimental catchment. Evapotranspiration values of this new method were compared tothe Penman-Monteith evapotranspiration values on a half hourly scale and to the White methodevapotranspiration values on a daily scale. Sensitivity analysis showed that the more reliable hydraulicversion of our ET estimation technique is most sensitive (i.e., linearly to the values of the saturatedhydraulic conductivity and specific yield taken from the riparian zone.

  3. The influence of riparian-hyporheic zone on the hydrological responses in an intermittent stream

    Directory of Open Access Journals (Sweden)

    A. Butturini

    2002-01-01

    Full Text Available Stream and riparian groundwater hydrology has been studied in a small intermittent stream draining a forested catchment for a system representative of a Mediterranean climate. The relationship between precipitation and stream runoff and the interactions between stream water and the surrounding riparian groundwater have been analysed under a wide spectrum of meteorological conditions. The hypothesis that the hydrological condition of the near-stream groundwater compartment can regulate the runoff generation during precipitation events was tested. Stream runoff is characterised by a summer dry period, and precipitation input explained only 25% of runoff variability over the study period (r2 =0.25, d.f.=51, p2=0.80, d.f.=34, p Keywords: riparian zone, groundwater hydrology, runoff, intermittent stream, Mediterranean climate

  4. Dynamics of soil inorganic nitrogen and their responses to nitrogen additions in three subtropical forests, south China

    Institute of Scientific and Technical Information of China (English)

    FANG Yun-ting; ZHU Wei-xing; MO Jiang-ming; ZHOU Guo-yi; GUNDERSEN Per

    2006-01-01

    Three forests with different historical land-use, forest age, and species assemblages in subtropical China were selected to evaluate current soil N status and investigate the responses of soil inorganic N dynamics to monthly ammonium nitrate additions.Results showed that the mature monsoon evergreen broadleaved forest that has been protected for more than 400 years exhibited an advanced soil N status than the pine (Pinus massoniana) and pine-broadleaf mixed forests, both originated from the 1930's clear-cut and pine plantation. Mature forests had greater extractable inorganic N pool, lower N retention capacity, higher inorganic N leaching,and higher soil C/N ratios. Mineral soil extractable NH4+-N and NO3--N concentrations were significantly increased by experimental N additions on several sampling dates, but repeated ANOVA showed that the effect was not significant over the whole year except NH4+-N in the mature forest. In contrast, inorganic N (both NH4+-N and NO3--N) in soil 20-cm below the surface was significantly elevated by the N additions. From 42% to 74% of N added was retained by the upper 20 cm soils in the pine and mixed forests, while 0%-70% was retained in the mature forest. Our results suggest that land-use history, forest age and species composition were likely to be some of the important factors that determine differing forest N retention responses to elevated N deposition in the study region.

  5. Long-term disturbance dynamics and resilience of tropical peat swamp forests.

    Science.gov (United States)

    Cole, Lydia E S; Bhagwat, Shonil A; Willis, Katherine J

    2015-01-01

    1. The coastal peat swamp forests of Sarawak, Malaysian Borneo, are undergoing rapid conversion, predominantly into oil palm plantations. This wetland ecosystem is assumed to have experienced insignificant disturbance in the past, persisting under a single ecologically-stable regime. However, there is limited knowledge of the past disturbance regime, long-term functioning and fundamentally the resilience of this ecosystem to changing natural and anthropogenic perturbations through time. 2. In this study, long-term ecological data sets from three degraded peatlands in Sarawak were collected to shed light on peat swamp forest dynamics. Fossil pollen and charcoal were counted in each sedimentary sequence to reconstruct vegetation and investigate responses to past environmental disturbance, both natural and anthropogenic. 3. Results demonstrate that peat swamp forest taxa have dominated these vegetation profiles throughout the last c . 2000-year period despite the presence of various drivers of disturbance. Evidence for episodes of climatic variability, predominantly linked to ENSO events, and wildfires is present throughout. However, in the last c . 500 years, burning and indicators of human disturbance have elevated beyond past levels at these sites, concurrent with a reduction in peat swamp forest pollen. 4. Two key insights have been gained through this palaeoecological analysis: (i) peat swamp forest vegetation has demonstrated resilience to disturbance caused by burning and climatic variability in Sarawak in the late Holocene, however (ii) coincident with increased fire combined with human impact c . 500 years ago, these communities started to decline. 5. Synthesis . Sarawak's coastal peat swamps have demonstrated resilience to past natural disturbances, with forest vegetation persisting through episodes of fire and climatic variability. However, palaeoecological data presented here suggest that recent, anthropogenic disturbances are of a greater magnitude

  6. Aerosol dynamics within and above forest in relation to turbulent transport and dry deposition

    Directory of Open Access Journals (Sweden)

    Ü. Rannik

    2016-03-01

    Full Text Available A 1-D atmospheric boundary layer (ABL model coupled with a detailed atmospheric chemistry and aerosol dynamical model, the model SOSAA, was used to predict the ABL and detailed aerosol population (characterized by the number size distribution time evolution. The model was applied over a period of 10 days in May 2013 to a pine forest site in southern Finland. The period was characterized by frequent new particle formation events and simultaneous intensive aerosol transformation. The aim of the study was to analyze and quantify the role of aerosol and ABL dynamics in the vertical transport of aerosols. It was of particular interest to what extent the fluxes above the canopy deviate from the particle dry deposition on the canopy foliage due to the above-mentioned processes. The model simulations revealed that the particle concentration change due to aerosol dynamics frequently exceeded the effect of particle deposition by even an order of magnitude or more. The impact was, however, strongly dependent on particle size and time. In spite of the fact that the timescale of turbulent transfer inside the canopy is much smaller than the timescales of aerosol dynamics and dry deposition, leading us to assume well-mixed properties of air, the fluxes at the canopy top frequently deviated from deposition inside the forest. This was due to transformation of aerosol concentration throughout the ABL and resulting complicated pattern of vertical transport. Therefore we argue that the comparison of timescales of aerosol dynamics and deposition defined for the processes below the flux measurement level do not unambiguously describe the importance of aerosol dynamics for vertical transport above the canopy. We conclude that under dynamical conditions reported in the current study the micrometeorological particle flux measurements can significantly deviate from the dry deposition into the canopy. The deviation can be systematic for certain size ranges so that the

  7. Seasonal dynamics of water use efficiency of typical forest and grassland ecosystems in China

    CERN Document Server

    Zhu, Xianjin; Wang, Qiufeng; Hu, Zhongmin; Han, Shijie; Yan, Junhua; Wang, Yanfen; Zhao, Liang

    2014-01-01

    We selected four sites of ChinaFLUX representing four major ecosystem types in China-Changbaishan temperate broad-leaved Korean pine mixed forest (CBS), Dinghushan subtropical evergreen broadleaved forest (DHS), Inner Mongolia temperate steppe (NM), and Haibei alpine shrub-meadow (HBGC)-to study the seasonal dynamics of ecosystem water use efficiency (WUE = GPP/ET, where GPP is gross primary productivity and ET is evapotranspiration) and factors affecting it. Our seasonal dynamics results indicated single-peak variation of WUE in CBS, NM, and HBGC, which were affected by air temperature (Ta) and leaf area index (LAI), through their effects on the partitioning of evapotranspiration (ET) into transpiration (T) (i.e., T/ET). In DHS, WUE was higher at the beginning and the end of the year, and minimum in summer. Ta and soil water content affected the seasonal dynamics of WUE through their effects on GPP/T. Our results indicate that seasonal dynamics of WUE were different because factors affecting the seasonal dyn...

  8. Winter climate controls soil carbon dynamics during summer in boreal forests

    International Nuclear Information System (INIS)

    Haei, Mahsa; Öquist, Mats G; Ilstedt, Ulrik; Laudon, Hjalmar; Kreyling, Juergen

    2013-01-01

    Boreal forests, characterized by distinct winter seasons, store a large proportion of the global terrestrial carbon (C) pool. We studied summer soil C-dynamics in a boreal forest in northern Sweden using a seven-year experimental manipulation of soil frost. We found that winter soil climate conditions play a major role in controlling the dissolution/mineralization of soil organic-C in the following summer season. Intensified soil frost led to significantly higher concentrations of dissolved organic carbon (DOC). Intensified soil frost also led to higher rates of basal heterotrophic CO 2 production in surface soil samples. However, frost-induced decline in the in situ soil CO 2 concentrations in summer suggests a substantial decline in root and/or plant associated rhizosphere CO 2 production, which overrides the effects of increased heterotrophic CO 2 production. Thus, colder winter soils, as a result of reduced snow cover, can substantially alter C-dynamics in boreal forests by reducing summer soil CO 2 efflux, and increasing DOC losses. (letter)

  9. Forest fire management to avoid unintended consequences: a case study of Portugal using system dynamics.

    Science.gov (United States)

    Collins, Ross D; de Neufville, Richard; Claro, João; Oliveira, Tiago; Pacheco, Abílio P

    2013-11-30

    Forest fires are a serious management challenge in many regions, complicating the appropriate allocation to suppression and prevention efforts. Using a System Dynamics (SD) model, this paper explores how interactions between physical and political systems in forest fire management impact the effectiveness of different allocations. A core issue is that apparently sound management can have unintended consequences. An instinctive management response to periods of worsening fire severity is to increase fire suppression capacity, an approach with immediate appeal as it directly treats the symptom of devastating fires and appeases the public. However, the SD analysis indicates that a policy emphasizing suppression can degrade the long-run effectiveness of forest fire management. By crowding out efforts to preventative fuel removal, it exacerbates fuel loads and leads to greater fires, which further balloon suppression budgets. The business management literature refers to this problem as the firefighting trap, wherein focus on fixing problems diverts attention from preventing them, and thus leads to inferior outcomes. The paper illustrates these phenomena through a case study of Portugal, showing that a balanced approach to suppression and prevention efforts can mitigate the self-reinforcing consequences of this trap, and better manage long-term fire damages. These insights can help policymakers and fire managers better appreciate the interconnected systems in which their authorities reside and the dynamics that may undermine seemingly rational management decisions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Temporal bird community dynamics are strongly affected by landscape fragmentation in a Central American tropical forest region

    Science.gov (United States)

    Blandón, A.C.; Perelman, S.B.; Ramírez, M.; López, A.; Javier, O.; Robbins, Chandler S.

    2016-01-01

    Habitat loss and fragmentation are considered the main causes of species extinctions, particularly in tropical ecosystems. The objective of this work was to evaluate the temporal dynamics of tropical bird communities in landscapes with different levels of fragmentation in eastern Guatemala. We evaluated five bird community dynamic parameters for forest specialists and generalists: (1) species extinction, (2) species turnover, (3) number of colonizing species, (4) relative species richness, and (5) a homogeneity index. For each of 24 landscapes, community dynamic parameters were estimated from bird point count data, for the 1998–1999 and 2008–2009 periods, accounting for species’ detection probability. Forest specialists had higher extinction rates and a smaller number of colonizing species in landscapes with higher fragmentation, thus having lower species richness in both time periods. Alternatively, forest generalists elicited a completely different pattern, showing a curvilinear association to forest fragmentation for most parameters. Thus, greater community dynamism for forest generalists was shown in landscapes with intermediate levels of fragmentation. Our study supports general theory regarding the expected negative effects of habitat loss and fragmentation on the temporal dynamics of biotic communities, particularly for forest specialists, providing strong evidence from understudied tropical bird communities.

  11. The StreamCat Dataset: Accumulated Attributes for NHDPlusV2 Catchments (Version 2.1) Riparian Buffer for the Conterminous United States: Forest Loss By Year 2001 to 2013

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset represents the characterization of global forest extent and change by year from 2001 through 2013 within individual local NHDPlusV2 catchments and...

  12. Estimating national forest carbon stocks and dynamics: combining models and remotely sensed information

    Science.gov (United States)

    Smallman, Thomas Luke; Exbrayat, Jean-François; Bloom, Anthony; Williams, Mathew

    2017-04-01

    Forests are a critical component of the global carbon cycle, storing significant amounts of carbon, split between living biomass and dead organic matter. The carbon budget of forests is the most uncertain component of the global carbon cycle - it is currently impossible to quantify accurately the carbon source/sink strength of forest biomes due to their heterogeneity and complex dynamics. It has been a major challenge to generate robust carbon budgets across landscapes due to data scarcity. Models have been used for estimating carbon budgets, but outputs have lacked an assessment of uncertainty, making a robust assessment of their reliability and accuracy challenging. Here a Metropolis Hastings - Markov Chain Monte Carlo (MH-MCMC) data assimilation framework has been used to combine remotely sensed leaf area index (MODIS), biomass (where available) and deforestation estimates, in addition to forest planting information from the UK's national forest inventory, an estimate of soil carbon from the Harmonized World Database (HWSD) and plant trait information with a process model (DALEC) to produce a constrained analysis with a robust estimate of uncertainty of the UK forestry carbon budget between 2000 and 2010. Our analysis estimates the mean annual UK forest carbon sink at -3.9 MgC ha-1 yr-1 with a 95 % confidence interval between -4.0 and -3.1 MgC ha-1yr-1. The UK national forest inventory (NFI) estimates the mean UK forest carbon sink to be between -1.4 and -5.5 MgC ha-1 yr-1. The analysis estimate for total forest biomass stock in 2010 is estimated at 229 (177/232) TgC, while the NFI an estimated total forest biomass carbon stock of 216 TgC. Leaf carbon area (LCA) is a key plant trait which we are able to estimate using our analysis. Comparison of median estimates for (LCA) retrieved from the analysis and a UK land cover map show higher and lower values for LCA are estimated areas dominated by needle leaf and broad leaf forests forest respectively, consistent with

  13. Cropland management dynamics as a driver of forest cover change in European Russia (Invited)

    Science.gov (United States)

    Tyukavina, A.; Krylov, A.; Potapov, P.; Turubanova, S.; Hansen, M.; McCarty, J. L.

    2013-12-01

    The European part of Russia spans over 40% of the European subcontinent and comprises most of Europe's temperate and boreal forests. The region has undergone a socio-economic transition during the last two decades that has resulted in radical changes in land management. Large-scale agriculture land abandonment caused massive afforestation in the Central and Northern parts of the region (Alcantara et al. 2012). Afforestation of former croplands is currently not included in the official forestry statistical reports (Potapov et al. 2012), but is likely to have major impacts on regional carbon budgets (Kuemmerle et al. 2009). We employed a complete archive of Landsat TM and ETM+ imagery and automatic data processing algorithm to create regional time-sequential image composites and multi-temporal metrics for 1985-2012. Spectral metrics were used as independent variables to map forest cover and change with help of supervised machine learning algorithms and trend analysis. Forest cover loss was attributed to fires, harvesting, and wind/disease dynamics, while forest cover gain was disaggregated into reforestation and afforestation using pre-1990 TM imagery as baseline data. Special attention was paid to agricultural abandonment. Fire events of the last decade have been further characterized by ignition place, time, and burning intensity using MODIS fire detection data. Change detection products have been validated using field data collected during summer 2012 and 2013 and high resolution imagery. Massive arable land abandonment caused forest area increase within Central agricultural regions. While total logging area decreased after the USSR breakdown, logging and other forms of clearing increased within the Central and Western parts of the region. Gross forest gain and loss were nearly balanced within region; however, the most populated regions of European Russia featured the highest rate of net forest cover loss during the last decade. The annual burned forest area as

  14. Quantifying Phosphorus Retnention in Soils of Riparian Buffers Influenced by Different Land Use Practices

    Science.gov (United States)

    Lancellotti, B.; Ross, D. S.; Adair, C.; Schroth, A. W.; Perdrial, J. N.

    2017-12-01

    Excess phosphorus (P) loading to freshwater systems can lead to eutrophication, resulting in algal blooms and subsequent fish kills. Lake Champlain, located between Vermont, New York, and Quebec, has historically exhibited negative effects of eutrophication due to P overloading from non-point sources. To reduce P inputs to the Lake, the Vermont Agency of Natural Resources requires and provides guidelines for the management of riparian buffers, which help protect adjacent water bodies from nutrient and sediment runoff. To better understand how phosphorous retention in riparian buffers is influenced by soil wetness and adjacent land use, we explored differences in P content between riparian buffers located in forested and agricultural watersheds. Within each land use type, we focused on two paired riparian buffers with contrasting soil moisture levels (one wet transect and one dry transect). At each of the four sites, soil pits were dug along a transect perpendicular to the streambank and were placed strategically to capture convergent and divergent landscape positions. Soil samples were collected from each horizon within 0-30cm. In each of these samples, we measured orthophosphate, degree of phosphorus saturation (DPS), and trace elements. We investigated the relationship between DPS and aluminum (Al) and iron (Fe) concentrations to determine how much of the variability in DPS was explained by Al and Fe concentrations, and compared these relationships between the four riparian buffer sites. We also assessed how these relationships varied with depth in the soil profile. The results of these analyses allow us to identify the characteristics of riparian buffers that promote the most effective P sequestration, which is beneficial to the effective management of riparian areas within the Lake Champlain basin.

  15. Using the Landsat data archive to assess long-term regional forest dynamics assessment in Eastern Europe, 1985-2012

    Science.gov (United States)

    Turubanova, S.; Potapov, P.; Krylov, A.; Tyukavina, A.; McCarty, J. L.; Radeloff, V. C.; Hansen, M. C.

    2015-04-01

    Dramatic political and economic changes in Eastern European countries following the dissolution of the "Eastern Bloc" and the collapse of the Soviet Union greatly affected land-cover and land-use trends. In particular, changes in forest cover dynamics may be attributed to the collapse of the planned economy, agricultural land abandonment, economy liberalization, and market conditions. However, changes in forest cover are hard to quantify given inconsistent forest statistics collected by different countries over the last 30 years. The objective of our research was to consistently quantify forest cover change across Eastern Europe from 1985 until 2012 using the complete Landsat data archive. We developed an algorithm for processing imagery from different Landsat platforms and sensors (TM and ETM+), aggregating these images into a common set of multi-temporal metrics, and mapping annual gross forest cover loss and decadal gross forest cover gain. Our results show that forest cover area increased from 1985 to 2012 by 4.7% across the region. Average annual gross forest cover loss was 0.41% of total forest cover area, with a statistically significant increase from 1985 to 2012. Most forest disturbance recovered fast, with only 12% of the areas of forest loss prior to 1995 not being recovered by 2012. Timber harvesting was the main cause of forest loss. Logging area declined after the collapse of socialism in the late 1980s, increased in the early 2000s, and decreased in most countries after 2007 due to the global economic crisis. By 2012, Central and Baltic Eastern European countries showed higher logging rates compared to their Western neighbours. Comparing our results with official forest cover and change estimates showed agreement in total forest area for year 2010, but with substantial disagreement between Landsat-based and official net forest cover area change. Landsat-based logging areas exhibit strong relationship with reported roundwood production at national

  16. RESEARCH NEEDS IN RIPARIAN BUFFER RESTORATION

    Science.gov (United States)

    Riparian buffer restorations are used as management tools to produce favorable water quality impacts; moreover, the basis for riparian buffers as an instrument of water quality restoration rests on a relatively firm foundation. However, the extent to which buffers can restore rip...

  17. Tamarisk coalition - native riparian plant materials program

    Science.gov (United States)

    Stacy Kolegas

    2012-01-01

    The Tamarisk Coalition (TC), a nonprofit organization dedicated to riparian restoration in the western United States, has created a Native Plant Materials Program to address the identified need for native riparian plant species for use in revegetation efforts on the Colorado Plateau. The specific components of the Native Plant Materials Program include: 1) provide seed...

  18. The Riparianness of a Desert Herpetofauna

    Science.gov (United States)

    Charles H. Lowe

    1989-01-01

    Within the Mojave, Sonoran, and Chihuahuan Desert subdivisions of the North American Desert in the U.S., more than half of 143 total amphibian and reptilian species perform as riparian and/or wetland taxa. For the reptiles, but not the amphibians, there is a significant inverse relationship between riparianness (obligate through preferential and facultative to...

  19. The Influence of Salmon Recolonization on Riparian Communities in the Cedar River, Washington, USA

    Science.gov (United States)

    Moravek, J.; Clipp, H.; Kiffney, P.

    2016-02-01

    Salmon are a valuable resource throughout the Pacific Northwest, but increasing human activity is degrading coastal ecosystems and threatening local salmon populations. Salmon conservation efforts often focus on habitat restoration, including the re-colonization of salmon into historically obstructed areas such as the Cedar River in Washington, USA. However, to assess the long term implications of salmon re-colonization on a landscape scale, it is critical to consider not only the river ecosystem but also the surrounding riparian habitat. Although prior studies suggest that salmon alter riparian food web dynamics, the riparian community on the Cedar River has not yet been characterized. To investigate possible connections between salmon and the riparian habitat after 12 years of re-colonization, we surveyed riparian spider communities along a gradient of salmon inputs (g/m2). In 10-m transects along the banks of the river, we identified spiders and spider webs, collected prey from webs, and characterized nearby aquatic macroinvertebrate communities. We found that the density of aquatic macroinvertebrates, as well as the density of spider prey, both had significant positive relationships with salmon inputs, supporting the hypothesis that salmon provide energy and nutrients for both aquatic and riparian food webs. We also found that spider diversity significantly decreased with salmon inputs, potentially due to confounding factors such as stream gradient or vegetation structure. Although additional information is needed to fully understand this relationship, the significant connection between salmon inputs and spider diversity is compelling motivation for further studies regarding the link between aquatic and riparian systems on the Cedar River. Understanding the connections between salmon and the riparian community is critical to characterizing the long term, landscape-scale implications of sustainable salmon management in the Pacific Northwest.

  20. Power and Conflict in Adaptive Management: Analyzing the Discourse of Riparian Management on Public Lands

    Directory of Open Access Journals (Sweden)

    Jennifer S. Arnold

    2012-03-01

    Full Text Available Adaptive collaborative management emphasizes stakeholder engagement as a crucial component of resilient social-ecological systems. Collaboration among diverse stakeholders is expected to enhance learning, build social legitimacy for decision making, and establish relationships that support learning and adaptation in the long term. However, simply bringing together diverse stakeholders does not guarantee productive engagement. Using critical discourse analysis, we examined how diverse stakeholders negotiated knowledge and power in a workshop designed to inform adaptive management of riparian livestock grazing on a National Forest in the southwestern USA. Publicly recognized as a successful component of a larger collaborative effort, we found that the workshop effectively brought together diverse participants, yet still restricted dialogue in important ways. Notably, workshop facilitators took on the additional roles of riparian experts and instructors. As they guided workshop participants toward a consensus view of riparian conditions and management recommendations, they used their status as riparian experts to emphasize commonalities with stakeholders supportive of riparian grazing and accentuate differences with stakeholders skeptical of riparian grazing, including some Forest Service staff with power to influence management decisions. Ultimately, the management plan published one year later did not fully adopt the consensus view from the workshop, but rather included and acknowledged a broader diversity of stakeholder perspectives. Our findings suggest that leaders and facilitators of adaptive collaborative management can more effectively manage for productive stakeholder engagement and, thus, social-ecological resilience if they are more tentative in their convictions, more critical of the role of expert knowledge, and more attentive to the knowledge, interests, and power of diverse stakeholders.

  1. Transporting dynamics of radioactive cesium in a forest ecosystem and its discharge processes

    Energy Technology Data Exchange (ETDEWEB)

    Iseda, Kohei; Ohte, Nobuhito; Tanoi, Keitaro; Endo, Izuki; Oda, Tomoki; Kato, Hiroyu [Graduate School of Agricultural and Life Sciences, University of Tokyo (Japan)

    2014-07-01

    A lot of radioactive substance including {sup 137}Cs, {sup 134}Cs fell out to Tohoku and Kanto region in particular Fukushima prefecture after the accident of Fukushima-daiichi nuclear power plant. Generally, cesium tends to attach to clay particle and organic matter. These clay particle and organic matter can potentially flow out from the forest through the river to the downstream not only as particulate matter but also dissolved matter. It is likely that behavior of cesium is similar to sediment locomotion. The objective of this study is to understand transporting dynamics of radioactive cesium inside and outside of the forest. We started investigations on transporting dynamics of cesium in the forest upper stream of Kami-Oguni river in Date city Fukushima prefecture located in about 50 km from the nuclear power plant since July 2012. We conducted river water sampling at 9 points along the river from the uppermost stream to the middle reaches during low flow condition once a month. We also sampled river water during storm event for 5 times in order to capture the change of {sup 137}Cs concentration in a flood stage. Samples were filtered and separated into particulate and dissolved matters using glass micro-fiber filters (GF/F). Samples were analyzed their {sup 137}Cs concentration by Germanium semiconductor detector at University of Tokyo. During low flow condition, {sup 137}Cs was detected only a very small amount both in particulate and dissolved matters. In contrast, during high flow condition, {sup 137}Cs was detected about 10-100 times higher than that of during low flow condition in particulate matter. We estimated discharge flux of {sup 137}Cs from the forest using the relations between water discharge and {sup 137}Cs concentration. It was 0.977 Bq/(m2 day ) (2012/8/31-2013/4/19). In the forest, we set 2 deciduous tree plots (Quercus serrata, Zelkova serrata and so on) and 1 evergreen confer plot (Cyptomeria japonica). Atmospheric depositions of {sup 137

  2. Human dynamics and forest management: a baseline assessment of the socioeconomic characteristics of the region surrounding the El Yunque National Forest

    Science.gov (United States)

    Kathleen McGinley

    2016-01-01

    In this paper, I examine the socioeconomic dynamics and human–environment interactions in the region surrounding the El Yunque National Forest (EYNF) in northeastern Puerto Rico and their implications for policy development and sustainable resource use. As part of a larger, comprehensive assessment of the conditions and trends of the EYNF and broader region, I...

  3. Linear compartment model of plutonium dynamics in a deciduous forest ecosystem

    International Nuclear Information System (INIS)

    Garten, C.T. Jr.; Gardner, R.H.; Dahlman, R.C.

    1977-01-01

    Systems ecology techniques have been useful in simulating the fate and dynamics of radionuclides in forest ecosystems. The applications of systems models in this context are twofold: projection of the time-dependent distribution of radioisotopes among various ecosystems components, and manipulation of the modeled system to determine the sensitivity of components to variation in transfer coefficients and, thereby, identify critical fluxes affecting system behavior. The present paper describes a systems model that projects the possible fate of plutonium in a deciduous forest ecosystem. The isotopes of interest are 239 Pu and 240 Pu which have physical half lives of 2.44 x 10 4 and 6540 years, respectively. These isotopes are indistinguishable by alpha spectrometry hence 239 Pu is used to refer to both

  4. Aerosol dynamics within and above forest in relation to turbulent transport and dry deposition

    DEFF Research Database (Denmark)

    Rannik, Üllar; Zhou, Luxi; Zhou, Putian

    2016-01-01

    of 10 days in May 2013 to a pine forest site in southern Finland. The period was characterized by frequent new particle formation events and simultaneous intensive aerosol transformation. The aim of the study was to analyze and quantify the role of aerosol and ABL dynamics in the vertical transport...... of aerosols. It was of particular interest to what extent the fluxes above the canopy deviate from the particle dry deposition on the canopy foliage due to the above-mentioned processes. The model simulations revealed that the particle concentration change due to aerosol dynamics frequently exceeded...... the effect of particle deposition by even an order of magnitude or more. The impact was, however, strongly dependent on particle size and time. In spite of the fact that the timescale of turbulent transfer inside the canopy is much smaller than the timescales of aerosol dynamics and dry deposition, leading...

  5. Evaluating the impact of abrupt changes in forest policy and management practices on landscape dynamics: analysis of a Landsat image time series in the Atlantic Northern Forest.

    Science.gov (United States)

    Legaard, Kasey R; Sader, Steven A; Simons-Legaard, Erin M

    2015-01-01

    Sustainable forest management is based on functional relationships between management actions, landscape conditions, and forest values. Changes in management practices make it fundamentally more difficult to study these relationships because the impacts of current practices are difficult to disentangle from the persistent influences of past practices. Within the Atlantic Northern Forest of Maine, U.S.A., forest policy and management practices changed abruptly in the early 1990s. During the 1970s-1980s, a severe insect outbreak stimulated salvage clearcutting of large contiguous tracts of spruce-fir forest. Following clearcut regulation in 1991, management practices shifted abruptly to near complete dependence on partial harvesting. Using a time series of Landsat satellite imagery (1973-2010) we assessed cumulative landscape change caused by these very different management regimes. We modeled predominant temporal patterns of harvesting and segmented a large study area into groups of landscape units with similar harvest histories. Time series of landscape composition and configuration metrics averaged within groups revealed differences in landscape dynamics caused by differences in management history. In some groups (24% of landscape units), salvage caused rapid loss and subdivision of intact mature forest. Persistent landscape change was created by large salvage clearcuts (often averaging > 100 ha) and conversion of spruce-fir to deciduous and mixed forest. In groups that were little affected by salvage (56% of landscape units), contemporary partial harvesting caused loss and subdivision of intact mature forest at even greater rates. Patch shape complexity and edge density reached high levels even where cumulative harvest area was relatively low. Contemporary practices introduced more numerous and much smaller patches of stand-replacing disturbance (typically averaging forest ecology.

  6. A dynamic organic soil biogeochemical model for simulating the effects of wildfire on soil environmental conditions and carbon dynamics of black spruce forests

    Science.gov (United States)

    Shuhua Yi; A. David McGuire; Eric Kasischke; Jennifer Harden; Kristen Manies; Michelle Mack; Merritt. Turetsky

    2010-01-01

    Ecosystem models have not comprehensively considered how interactions among fire disturbance, soil environmental conditions, and biogeochemical processes affect ecosystem dynamics in boreal forest ecosystems. In this study, we implemented a dynamic organic soil structure in the Terrestrial Ecosystem Model (DOS-TEM) to investigate the effects of fire on soil temperature...

  7. Nitrogen limitation of growth and nutrient dynamics in a disturbed mangrove forest, Indian River Lagoon, Florida

    Science.gov (United States)

    Feller, Ilka C.; Whigham, D.F.; McKee, K.L.; Lovelock, C.E.

    2003-01-01

    The objectives of this study were to determine effects of nutrient enrichment on plant growth, nutrient dynamics, and photosynthesis in a disturbed mangrove forest in an abandoned mosquito impoundment in Florida. Impounding altered the hydrology and soil chemistry of the site. In 1997, we established a factorial experiment along a tree-height gradient with three zones, i.e., fringe, transition, dwarf, and three fertilizer treatment levels, i.e., nitrogen (N), phosphorus (P), control, in Mosquito Impoundment 23 on the eastern side of Indian River. Transects traversed the forest perpendicular to the shoreline, from a Rhizophora mangle-dominated fringe through an Avicennia germinans stand of intermediate height, and into a scrub or dwarf stand of A. germinans in the hinterland. Growth rates increased significantly in response to N fertilization. Our growth data indicated that this site is N-limited along the tree-height gradient. After 2 years of N addition, dwarf trees resembled vigorously growing saplings. Addition of N also affected internal dynamics of N and P and caused increases in rates of photosynthesis. These findings contrast with results for a R. mangle-dominated forest in Belize where the fringe is N-limited, but the dwarf zone is P-limited and the transition zone is co-limited by N and P. This study demonstrated that patterns of nutrient limitation in mangrove ecosystems are complex, that not all processes respond similarly to the same nutrient, and that similar habitats are not limited by the same nutrient when different mangrove forests are compared.

  8. Dynamics of combined forest damage risks for 21st century (SRES A1B, B1)

    Science.gov (United States)

    Panferov, Oleg; Merklein, Johannes; Sogachev, Andrey; Junghans, Udo; Ahrends, Bernd

    2010-05-01

    of forest ecosystems, wind loading on trees and biotic damage for several tree species and typical soil types. The damage risks a certain forest stand at a given soil results from daily combinations of air and soil temperatures, soil water characteristics, static and gust wind loads on trees with dynamic LAI and of soil texture. Some damaged stands show higher vulnerability and thus - positive feedbacks to climate forcing (Vygodskaya et al., 2007). Therefore, changes of microclimate in remaining stands after changes in forest structure are taken into account. Model output is aggregated to 30-years periods and compared to "present conditions" of 1981-2010. The results show considerable increment of both biotic and abiotic risks towards 2100 relatively to "present" caused by weak changes in precipitation and wind patterns and strong increase of mean air temperature and soil temperatures. It is shown, e.g. that the wind- damage-induced changes of structure and microclimate provide a positive feedback i.e. - increase the probability of the next damage event. The study was financed by BMBF within the frames of joint project "Decision Support System - Forest and Climate Change" (DSS-WuK) and by Grant of Ministry for Science and Culture of Lower Saxony "KLIFF". We gratefully acknowledge this support.

  9. Post Wildfire Changes in Plant Functioning and Vegetation Dynamics: Implications for Water Fluxes in Re-sprouting Forests

    Science.gov (United States)

    Nolan, R. H.; Lane, P. N.; Mitchell, P. J.; Bradstock, R. A.

    2011-12-01

    Fire induced changes to the vegetation dynamics in temperate forests have been demonstrated to affect evapotranspiration (Et) rates through increases in plant size and density and stand-level transpiration and interception. In many cases these transient changes in forest structure result in substantial declines in stream flow for protracted periods after the disturbance. However to date research has focused on the wetter 'ash' forests of south-eastern Australia which solely regenerate via seedlings, it is unknown what changes in Et may occur in those forests which re-sprout post-fire. We hypothesize that Et fluxes track post-fire changes in sapwood area and leaf area index (L) in re-sprouting temperate forests, increasing as the forest regenerates. Following the 2009 Black Saturday wildfires in Victoria, we monitored Et rates for over a year in both damp and dry re-sprouting forest, incorporating a range of fire severity classes. Components of Et including overstorey transpiration, rainfall interception loss and forest floor Et were measured in conjunction with changes in L, sapwood area and leaf physiology. The monitoring period began one year post-fire with a typical hot, dry summer, at which stage Et rates in burnt forest were similar or less than those in unburnt forest. During the following summer, which was one of the wettest on record, Et increased across all monitoring plots but particularly so in the burnt forest where seedling regeneration resulted in an understorey L nearly twice that of unburnt forest. Forest floor Et was up to 46% higher in burnt forest, and rainfall interception values accounted for approximately 25% of rainfall compared to 15% in unburnt forest. The greatest increase in canopy transpiration rates over this period occurred in those trees subject to a low intensity fire where most of the canopy remained intact but there was also fire-triggered sprouting of new leaves along the trunk and main branches. In these trees rates of sapflow

  10. Dynamics of Phosphorus export from small forested catchments in low mountain ranges in Germany

    Science.gov (United States)

    Julich, Stefan; Julich, Dorit; Benning, Raphael; Feger, Karl-Heinz

    2017-04-01

    Phosphorus (P) plays an important role in the nutrition of forest ecosystem. The transport of P in forest soils predominantly occurs along preferential water flow pathways bypassing large parts of the soil matrix. Therefore, rapid flow processes by preferential flow and/or during storm events may lead to significant P losses from forest soils. However only little knowledge about the dynamics, magnitude and driving processes of P exports into surface water exist. In this contribution, we present the results of two studies where two small forested catchments have been monitored for a period around 3 years. Both catchments are situated in low mountain ranges in Saxony (catchment size 21 ha) and Thuringia (catchment size 5 ha) representing medium P contents in the topsoil of 1142 mg kg-1 and 834 mg kg-1 respectively. During the regular sampling (monthly to weekly sampling frequency), the mean Total-P concentrations of 23 μg L-1(Thuringian Site) and 8 μg L-1(Saxonian Site) have been measured. However, during single storm events Total-P concentrations increased considerably with maximum concentrations of 134 μg L-1(Thuringian Site) and 203 μg L-1(Saxonian Site). Our findings indicate that during storm events, especially after longer dry periods, significant amounts of phosphorus can be exported from forest ecosystems. Comparison of discharge-concentration patterns of Total-P, Nitrogen and DOC, as well as dye tracer experiments, suggest that preferential flow along biopores and stone surfaces, and the interface between mineral soil and litter layer are main pathways of export from forests. For the site in Saxony we calculated mean annual export rates of 32.8 to 33.5 g ha-1 a-1 based on the weekly sampling with different load calculation methods (flow weighted methods up to linear regression models). If the events are included into the annual load calculation the mean annual export fluxes increase from 47.8 to 58.6 g ha-1 a-1 based on the different load calculation

  11. Growing up with stress - carbon sequestration and allocation dynamics of a broadleaf evergreen forest

    Science.gov (United States)

    Griebel, Anne; Bennett, Lauren T.; Arndt, Stefan K.

    2016-04-01

    Evergreen forests have the potential to sequester carbon year-round due to the presence of leaves with a multi-year lifespan. Eucalypt forests occur in warmer climates where temperature and radiation are not imposing a strong seasonality. Thus, unlike deciduous or many coniferous trees, many eucalypts grow opportunistically as conditions allow. As such, many eucalypts do not produce distinct growth rings, which present challenges to the implementation of standard methods and data interpretation approaches for monitoring and explaining carbon allocation dynamics in response to climatic stress. As a consequence, there is a lack of detailed understanding of seasonal growth dynamics of evergreen forests as a whole, and, in particular, of the influence of climatic drivers on carbon allocation to the various biomass pools. We used a multi-instrument approach in a mixed species eucalypt forest to investigate the influence of climatic drivers on the seasonal growth dynamics of a predominantly temperate and moisture-regulated environment in south-eastern Australia. Ecosystem scale observations of net ecosystem exchange (NEE) from a flux tower in the Wombat forest near Melbourne indicated that the ecosystem is a year-round carbon sink, but that intra-annual variations in temperature and moisture along with prolonged heat waves and dry spells resulted in a wide range of annual sums over the past three years (NEE ranging from ~4 to 12 t C ha-1 yr-1). Dendrometers were used to monitor stem increments of the three dominant eucalypt species. Stem expansion was generally opportunistic with the greatest increments under warm but moist conditions (often in spring and autumn), and the strongest indicators of stem growth dynamics being radiation, vapour pressure deficit and a combined heat-moisture index. Differences in the seasonality of stem increments between species were largely due to differences in the canopy position of sampled individuals. The greatest stem increments were

  12. Wildlife Response to Riparian Restoration on the Sacramento River

    Directory of Open Access Journals (Sweden)

    Gregory H Golet

    2008-06-01

    Full Text Available Studies that assess the success of riparian restoration projects seldom focus on wildlife. More generally, vegetation characteristics are studied, with the assumption that animal populations will recover once adequate habitats are established. On the Sacramento River, millions of dollars have been spent on habitat restoration, yet few studies of wildlife response have been published. Here we present the major findings of a suite of studies that assessed responses of four taxonomic groups (insects, birds, bats, and rodents. Study designs fell primarily into two broad categories: comparisons of restoration sites of different ages, and comparisons of restoration sites with agricultural and remnant riparian sites. Older restoration sites showed increased abundances of many species of landbirds and bats relative to younger sites, and the same trend was observed for the Valley elderberry longhorn beetle (Desmocerus californicus dimorphus, a federally threatened species. Species richness of landbirds and ground-dwelling beetles appeared to increase as restoration sites matured. Young restoration sites provided benefits to species that utilize early successional riparian habitats, and after about 10 years, the sites appeared to provide many of the complex structural habitat elements that are characteristic of remnant forest patches. Eleven-year old sites were occupied by both cavity-nesting birds and special-status crevice-roosting bats. Restored sites also supported a wide diversity of bee species, and had richness similar to remnant sites. Remnant sites had species compositions of beetles and rodents more similar to older sites than to younger sites. Because study durations were short for all but landbirds, results should be viewed as preliminary. Nonetheless, in aggregate, they provide convincing evidence that restoration along the Sacramento River has been successful in restoring riparian habitats for a broad suite of faunal species. Not only did

  13. Carbon and Nitrogen dynamics in forest soils depending on light conditions and tree species

    Science.gov (United States)

    Veselinovic, Bojana; Hager, Herbert

    2013-04-01

    Climate change mitigation actions under the Kyoto Protocol apply among other decreases of CO2-emissions and/or increases of carbon (C) stocks. As soils represent the second biggest C-reservoir on Earth, an exact estimation of the stocks and reliable knowledge on C-dynamics in forest soils is of high importance. Anyhow, here, the accurate GHG-accounting, emission reductions and increase in C stocks is hampered due to lack of reliable data and solid statistical methods for the factors which influence C-sequestration in and its release from these systems. In spite of good progress in the scientific research, these factors are numerous and diverse in their interactions. This work focuses on influence of the economically relevant tree species - Picea abies, Fagus sylvatica and Quercus spp. - and light conditions on forest floor and mineral soil C and N dynamics in forest soils. Spruce monocultures have been widely used management practices in central European forests during the past century. Such stands are in lower altitudes and on heavy and water logged soils unstable and prone to disturbances, especially to windthrows. We hypothesize that windthrow areas loose C & N and that the establishment of the previous nutrient stocks is, if at all, only possible to be reached over the longer periods of time. We research also how the increased OM depletion affects the change of C & N stocks in forest floor vs. mineral soil. Conversion of such secondary spruce monocultures to site adequate beech and oak forests may enable higher stocks allocated predominantly as stable organic carbon and as plant available nitrogen. For this purpose sites at 300-700 m altitude with planosols were chosen in the region of the Northern Alpine Foothills. A false chronosequence approach was used in order to evaluate the impacts of the tree species and change in light conditions on dynamic of C & N in the forest floor and mineral soil, over the period 0-100 (for oak 120 y.) years. The C- and N

  14. Orowan strengthening and forest hardening superposition examined by dislocation dynamics simulations

    International Nuclear Information System (INIS)

    Queyreau, Sylvain; Monnet, Ghiath; Devincre, Benoit

    2010-01-01

    Rule of mixtures are an essential feature of the modeling of plastic deformation in complex materials in which more than one strain-hardening mechanism is involved. In this work, use is made of dislocation dynamics simulations to characterize the individual and the superposed contributions of two major mechanisms of crystal plasticity, i.e. Orowan strengthening and forest hardening. Based on a formal description of each hardening mechanism, evidence is presented to show that a quadratic rule of mixtures has the ability to predict quantitatively the flow stress of complex materials such as reactor pressure vessel steel.

  15. Impacts of hydroelectric dams on alluvial riparian plant communities in Eastern Brazilian Amazonian.

    Science.gov (United States)

    Ferreira, Leandro Valle; Cunha, Denise A; Chaves, Priscilla P; Matos, Darley C L; Parolin, Pia

    2013-09-01

    The major rivers of the Amazon River basin and their biota are threatened by the planned construction of large hydroelectric dams that are expected to have strong impacts on floodplain plant communities. The present study presents forest inventories from three floodplain sites colonized by alluvial riparian vegetation in the Tapajós, Xingu and Tocantins River basins in eastern Amazonian. Results indicate that tree species of the highly specialized alluvial riparian vegetation are clearly distinct among the three river basins, although they are not very distinct from each other and environmental constraints are very similar. With only 6 of 74 species occurring in all three inventories, most tree and shrub species are restricted to only one of the rivers, indicating a high degree of local distribution. Different species occupy similar environmental niches, making these fragile riparian formations highly valuable. Conservation plans must consider species complementarily when decisions are made on where to place floodplain forest conservation units to avoid the irreversible loss of unique alluvial riparian vegetation biodiversity.

  16. Impacts of hydroelectric dams on alluvial riparian plant communities in eastern Brazilian Amazonian

    Directory of Open Access Journals (Sweden)

    LEANDRO VALLE FERREIRA

    2013-09-01

    Full Text Available The major rivers of the Amazon River basin and their biota are threatened by the planned construction of large hydroelectric dams that are expected to have strong impacts on floodplain plant communities. The present study presents forest inventories from three floodplain sites colonized by alluvial riparian vegetation in the Tapajós, Xingu and Tocantins River basins in eastern Amazonian. Results indicate that tree species of the highly specialized alluvial riparian vegetation are clearly distinct among the three river basins, although they are not very distinct from each other and environmental constraints are very similar. With only 6 of 74 species occurring in all three inventories, most tree and shrub species are restricted to only one of the rivers, indicating a high degree of local distribution. Different species occupy similar environmental niches, making these fragile riparian formations highly valuable. Conservation plans must consider species complementarily when decisions are made on where to place floodplain forest conservation units to avoid the irreversible loss of unique alluvial riparian vegetation biodiversity.

  17. Spatial and Temporal Relationships of Old-Growth and Secondary Forests in Indiana, USA

    Science.gov (United States)

    Martin A. Spetich; George R. Parker; Eric J. Gustafson

    1997-01-01

    We examined the spatial pattern of forests in Indiana to: (1) determine the extent, connectivity and percent edge of all forests, (2) examine the change in connectivity among these forests if all riparian zones were replanted to forest or other native vegetation, (3) determine the location, spatial dispersion and percent edge of current old-growth forest remnants, (4)...

  18. Litter Dynamics in a Forest Dune at Restinga da Marambaia, RJ, Brazil

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    Rodrigo Camara

    2018-03-01

    Full Text Available ABSTRACT Restingas are extremely degraded, tropical sandy ecosystems and are poorly studied in terms of nutrient cycling. The present study aimed to evaluate litter dynamics in a forest dune at Restinga da Marambaia, RJ. Litterfall was collected monthly using two parallel transects installed 200 m apart from each other with 15 litter traps (0.25 m2, over two consecutive years. The litterfall was sorted into leaves, twigs, flowers, fruits, and refuse. Litter decomposition was evaluated by the ratio between litterfall and litter layer on the soil surface, which was estimated every four months by quadrats (0.25 m2 placed next to the litter traps. The average annual litterfall was low (6.8 t ha-1 yea