Treesearch

Aboveground net primary production provides valuable information on wildlife habitat, fire fuel loads, and forage availability. Aboveground net primary production in herbaceous plant communities is typically measured by clipping aboveground biomass. However, the high costs associated with physically harvesting plant biomass may prevent collecting sufficient data to account for natural spatial and temporal variability of vegetation at a landscape scale. Various double-sampling techniques have been developed to increase sample size while reducing cost. We applied a biomass estimation...

We examine 31 years (1982-2012) of temperature, precipitation and natural wildfire occurrence data for Federal and Tribal lands to determine landscape-scale patterns of drought and fire on the southern and central High Plains of the western United States. The High Plains states of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas and Wyoming have been in the midst of ongoing extreme drought, experiencing below normal precipitation and above normal temperatures for the past several years. Climate change is predicted to have multiple effects on fire regimes. Longer...

We studied elk (Cervus canadensis nelsoni) parturition sites at coarse (314-km2 and 7-km2) and fine (0.2-ha) scales in the Black Hills, South Dakota, 2011-2013, following a period of population decline and poor calf recruitment. Our objective was to test whether female elk selected parturition sites across spatial scales in association with forage, terrain ruggedness, road density, or hiding and security cover. At coarse scales in forests and grasslands, female elk selected sites in areas with greater proportions of vegetation communities that provided forage (56-74% of area) and more...

Patterns of reproductive output in blackbrush did not track current growing season precipitation, but instead were regulated by prior-year weather cues. The strength of the response to the masting cue depended on habitat quality, with higher mean reproductive output, shorter intervals between years of high seed production, and lower CVp at more favorable sites. Wind pollination efficiency was demonstrated to be an important evolutionary driver of masting in blackbrush, and satiation of heteromyid seed predator-dispersers was supported as an evolutionary driver based on earlier studies.

Phytophthora tentaculata Kröber & Marwitz was described in 1993 in Germany on greenhouse-grown nursery ornamentals. It has since been found in Italy, Spain, China and the U.S. (California) causing a root and stem rot of many different plant species including nursery-grown native species used for habitat restoration. P. tentaculata is homothallic and is classified in Stamps group I which is characterized by the production of mostly paragynous antheridia, papillate sporangia and the production of both hyphal swellings and chlamydospores in culture. P. tentaculata is placed in phylogenetic...

Aim Forest regeneration data provide an early signal of the persistence and migration of tree species, so we investigated whether species shifts due to climate change exhibit a common signal of response or whether changes vary by species. Location California Floristic Province, United States; mediterranean biome. Methods We related Forest Inventory and Analysis (FIA) data from 2000−07 for 13 tree species to high-resolution climate and geographical data. Using methods from invasion ecology, we derived indices of species-specific regeneration overlap and central tendency change (range-wide...

Landsat data has long been used to support forest monitoring and management decisions despite the limited success of passive optical remote sensing for accurate estimation of structural attributes such as aboveground biomass. The archive of publicly available Landsat images dating back to the 1970s can be used to predict historic forest biomass dynamics. In addition, increasing regional scale availability and high sensitivity of LiDAR for biomass mapping also needs exploration of its utility in back-projection modeling. This study has combined recent national forest inventory (NFI) data...

The forest carbon accounting system used in recent National Greenhouse Gas Inventories (NGHGI) was developed more than a decade ago when the USDA Forest Service, Forest Inventory and Analysis annual inventory system was in its infancy and contemporary questions regarding the terrestrial sink (e.g., attribution) did not exist. The time has come to develop a new framework that can quickly address new questions, enables forest carbon analytics, and uses all the inventory information (e.g., disturbances and land use change) while having the flexibility to engage a wider breadth of stakeholders...

Forest carbon accounting techniques are changing. This year, a new accounting system is making its debut with the production of forest carbon data for EPA’s National Greenhouse Gas Inventory. The Forest Service’s annualized inventory system is being more fully integrated into estimates of forest carbon at the national and state levels both for the present and the recent past. With the advent of this new accounting system, however, a need persists for information at smaller scales. For example, National Forest managers are being asked to incorporate carbon management into Forest planning....

Federal forests in the Pacific Northwest region have undergone exceptional changes in management over the past 20 years, and these changes have led to a reduction in regional timber production and significant changes in the management and current age structure of forests. Public lands include large areas of older forests with relatively little younger early-seral forests. In contrast, private lands include large areas of younger forests and little land in older forests. The lack of early-seral forests on federal lands is an important and distinguishing characteristic of these forests and...