John B. Bradford

14 items:

Human Modification 2020 (Fig. 11) - A Sagebrush Conservation Design to Proactively Restore America’s Sagebrush Biome 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... Categories: Data; Tags: Arizona, California, Colorado, Complete, Data, All tags...
Natural Regeneration Processes in Big Sagebrush (Artemisia tridentata) 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, All tags...
Looking for age-related growth decline in natural forests: unexpected biomass patterns from tree rings and simulated mortality 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, All tags...
Trajectories and tipping points of piñon–juniper woodlands after fire and thinning Piñon–juniper (PJ) woodlands are a dominant community type across the Intermountain West, comprising over a million acres and experiencing critical effects from increasing wildfire. Large PJ mortality and regeneration failure after catastrophic wildfire have elevated concerns about the long-term viability of PJ woodlands. Thinning is increasingly used to safeguard forests from fire and in an attempt to increase climate resilience. We have only a limited understanding of how fire and thinning will affect the structure and function of PJ ecosystems. Here, we examined vegetation structure, microclimate conditions, and PJ regeneration dynamics following ~20 years post-fire and thinning treatments. We found that burned... Categories: Publication; Types: Citation
Long-term Experimental Forest Growth and Drought Data 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... Categories: Data; Tags: Argonne Experimental Forest, Arizona, Bartlett Experimental Forest, Birch Lake Experiment, Black Hills Experimental Forest, All tags...

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