Filters: partyWithName: John B. Bradford (X)
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Abstract (from: http://link.springer.com/article/10.1007/s00442-014-2881-2): Forest biomass growth is almost universally assumed to peak early in stand development, near canopy closure, after which it will plateau or decline. The chronosequence and plot remeasurement approaches used to establish the decline pattern suffer from limitations and coarse temporal detail. We combined annual tree ring measurements and mortality models to address two questions: first, how do assumptions about tree growth and mortality influence reconstructions of biomass growth? Second, under what circumstances does biomass production follow the model that peaks early, then declines? We integrated three stochastic mortality models with...
Categories: Publication;
Types: Citation;
Tags: Birds,
Forests,
Landscapes,
Northeast CASC,
Wildlife and Plants,
File-based data for download: https://www.sciencebase.gov/catalog/item/632a1290d34e71c6d67b9061Related report with figures: https://doi.org/10.3133/ofr20221081Location and extent of the human modification threat across the sagebrush biome in the United States for 2020. Blue areas (dark and light,representing core sagebrush areas [CSAs] and growth opportunity areas [GOAs], respectively) are locations of high sagebrush ecological integrityand could serve as anchor points in an overall biome-wide strategy. A separate, high-resolution portable document format (PDF) version of this mapis available at https://doi.org/10.3133/ofr20221081 so that stakeholders can zoom in and see the results at much smaller scales. By zooming...
Abstract (from http://www.srmjournals.org/doi/abs/10.2111/REM-D-13-00079.1): Big sagebrush, Artemisia tridentata Nuttall (Asteraceae), is the dominant plant species of large portions of semiarid western North America. However, much of historical big sagebrush vegetation has been removed or modified. Thus, regeneration is recognized as an important component for land management. Limited knowledge about key regeneration processes, however, represents an obstacle to identifying successful management practices and to gaining greater insight into the consequences of increasing disturbance frequency and global change. Therefore, our objective is to synthesize knowledge about natural big sagebrush regeneration. We identified...
Categories: Publication;
Types: Citation;
Tags: North Central CASC,
Plants,
Wildlife and Plants,
recruitment,
sage-grouse habitat,
These data were compiled in order to represent long-term (multi-decadal) forest growth across eight different experimental forests in the United States, each with replicated levels of density treatments, as well as an important drought index correlated to growth. Forests around the world are experiencing severe droughts and elevated competitive intensity due to increased tree density. These data can be utilized to not only examine differences in within-stand competition, as well the trends and impact of drought in different forests across a broad climatic gradient, but also the influence of interactions between drought and competition on forest growth. Growth is measured as a treatment level, annual basal area increment...
Drylands cover 40% of the global terrestrial surface and provide important ecosystem services. While drylands as a whole are expected to increase in distribution and aridity in coming decades, temperature and precipitation forecasts vary by latitude and geographic region suggesting different trajectories for tropical, subtropical, and temperate drylands. Uncertainty in the future of tropical and subtropical drylands is well constrained, whereas soil moisture and ecological droughts, which drive vegetation productivity and composition, remain poorly understood in temperate drylands. Here we show that, over the 21st century, temperate drylands may contract by a third, primarily converting to subtropical drylands,...
Categories: Data,
Publication;
Types: Citation;
Tags: Eastern Asia,
North America,
South America,
Southern Africa,
USGS Science Data Catalog (SDC),
File-based data for download: https://www.sciencebase.gov/catalog/item/632a33ced34e71c6d67b914fRelated report with figures: https://doi.org/10.3133/ofr20221081Location and extent of three mapped threats (invasive annual grasses, expanding conifers, and human modification) with core sagebrush areas and growth opportunity areas across the sagebrush biome of theUnited States for 2020. Blue areas (dark and light, representing core sagebrush areas [CSAs] and growth opportunity areas [GOAs], respectively) arelocations of high sagebrush ecological integrity and could serve as anchor points in an overall biome-wide strategy.Sagebrush foliage percent cover is a definitive characteristic of the ecosystem and relevant to persistence...
Abstract (from http://forestry.oxfordjournals.org/content/87/5/629.abstract): The contribution of understorey vegetation (UVEG) to forest ecosystem biomass and carbon (C) across diverse forest types has, to date, eluded quantification at regional and national scales. Efforts to quantify UVEG C have been limited to field-intensive studies or broad-scale modelling approaches lacking field measurements. Although large-scale inventories of UVEG C are not common, species- and community-level inventories of vegetation structure are available and may prove useful in quantifying UVEG C stocks. This analysis developed a general framework for estimating UVEG C stocks by employing per cent cover estimates of UVEG from a region-wide...
File-based data for download: https://www.sciencebase.gov/catalog/item/6328f759d34e71c6d67b7a40Related report with figures: https://doi.org/10.3133/ofr20221081Identifying anchor points (that is, areas of spatial congruence) between core sagebrush areas (CSAs) and growth opportunity areas (GOAs) and existing (as of 2020) agency prioritizations within the sagebrush biome. Locations where core sagebrush areas and growth opportunity areas co-occur were mapped with at least one of the following designations: (a) Centrocercus urophasianus L. (greater sage-grouse) Priority Areas for Conservation (PACs), as used by State agencies and the National Resources Conservation Service; (b) Priority Habitat Management Areas (PHMAs),...
File-based data for download:https://www.sciencebase.gov/catalog/item/632a06dcd34e71c6d67b902fRelated report with figures: https://doi.org/10.3133/ofr20221081Location and extent of the conifer threat across the sagebrush biome in the United States for 2020. Blue areas (dark and light, representing core sagebrush areas [CSAs] and growth opportunity areas [GOAs], respectively) are locations of high sagebrush ecological integrity and could serve as anchor points in an overall biome-wide strategy. A separate, high-resolution portable document format (PDF) version of this map is available at https://doi.org/10.3133/ofr20221081 so stakeholders can zoom in and see the results at much smaller scales. By zooming in, one...
Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/ecs2.1590/full): Ecohydrological responses to climate change will exhibit spatial variability and understanding the spatial pattern of ecological impacts is critical from a land management perspective. To quantify climate change impacts on spatial patterns of ecohydrology across shrub steppe ecosystems in North America, we asked the following question: How will climate change impacts on ecohydrology differ in magnitude and variability across climatic gradients, among three big sagebrush ecosystems (SB-Shrubland, SB-Steppe, SB-Montane), and among Sage-grouse Management Zones? We explored these potential changes for mid-century for RCP8.5 using a process-based...
Categories: Publication;
Types: Citation;
Tags: Landscapes,
North Central CASC,
Other Landscapes,
Plants,
Wildlife and Plants
File-based data for download:https://www.sciencebase.gov/catalog/item/6329f0f4d34e71c6d67b8f82Related report with figures: https://doi.org/10.3133/ofr20221081Location and extent of the invasive annual grass threat across the sagebrush biome in the United States for 2020. Blue areas (dark and light, representing core sagebrush areas [CSAs] and growth opportunity areas [GOAs], respectively) are locations of high sagebrush ecological integrity and could serve as anchor points in an overall biome-wide strategy. A separate, high-resolution portable document format (PDF) version of this map is available at https://doi.org/10.3133/ofr20221081 so stakeholders can zoom in and see the results at much smaller scales. By zooming...
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