Treesearch

Longleaf pine (Pinus palustris P. Mill) survival and growth, net nitrogen mineralization, and soil microbial biomass, were evaluated after four growing seasons in a Florida wet flatwoods site following chemical vegetation control during the first year or second year after planting, or during both years. The four herbicide treatments included sulfometuron methyl at 0.26 ai kg ha-1, hexazinone (0.56 ai kg ha-1), sulfometuron (0.26 ai kg ha-1) plus hexazinone (0.56 ai kg ha-1) mix, and imazapyr at 0.21 ai kg ha-1. Imazapyr was the only treatment to significantly improve growth over the...

Identifying the mechanisms by which globally pervasive changes in habitat affect predators is a central, yet challenging, endeavor in applied ecology. Cryptic shifts in trophic interactions are potentially important but widely underappreciated mechanisms shaping predator population response to habitat change. Here, we assessed the extent to which variation in trophic interactions explained differences in predator populations at both local and landscape scales. We integrated stable isotope analyses, GPS tagging, and long-term territory occupancy information to characterize the trophic...

The Northwest Forest Plan (NWFP) has guided the management of 17 federal forests in the US Pacific Northwest for the past 25 years. The existing management plans for these national forests – which were amended by the NWFP – are now being evaluated for revision under the US Forest Service’s 2012 planning rule. To help inform federal land managers, we reviewed the scientific literature published since the inception of the NWFP and report several key findings: (1) conservation of at-risk species within national forests is challenging in the face of threats that are beyond the control of...

This report highlights key findings from 2012 data collected by the Forest Inventory and Analysis program across all forested land on four islands in American Samoa, updating previously published findings from data collected in 2001 (Donnegan et al. 2004). We summarize and interpret basic resource information such as estimates of forest area, stem volume, biomass, numbers of trees, damages to trees, and tree size distribution as well as overstory and understory vegetation cover and information on invasive plant species presence and cover. Detailed tables and graphical highlights are...

British Columbia experienced three years with notably large and severe wildfires since 2015. Multiple stand-replacing wildfires occurred in coastal–transitional forests, where large fires are typically rare, and thus, information on post-fire carbon is lacking. Because of their carbon storage potential, coastal–transitional forests are important in the global carbon cycle. We examined differences in surface fuel carbon among fire severity classes in 2016, one year after the Boulder Creek fire, which burned 6 735 ha of coastal–transitional forests in 2015. Using remotely sensed indices...

The Ecosystem Management Decision Support (EMDS) system has been further enhanced with an analytical engine—BayesFusion’s SMILE (Structural Modeling, Inference, and Learning Engine) that comes with the GeNIe (Graphical Network Interface) software—for creating Bayesian network (BN) models. BNs are graphical networks of variables linked by probabilities, that have proven useful in decision-aiding for risk analysis and risk management.

Low-cost methods to measure forest structure are needed to consistently and repeatedly inventory forest conditions over large areas. In this study we investigate low-cost pushbroom Digital Aerial Photography (DAP) to aid in the estimation of forest volume over large areas in Washington State (USA). We also examine the effects of plot location precision (low versus high) and Digital Terrain Model (DTM) resolution (1 m versus 10 m) on estimation performance. Estimation with DAP and post-stratification with high-precision plot locations and a 1 m DTM was 4 times as efficient (precision per...

Conservation planning for wildlife species requires mapping and assessment of habitat suitability across broad areas, often relying on a diverse suite, or stack, of geospatial data presenting multidimensional controls on a species. Stacks of univariate, independently developed vegetation layers may not represent relationships between each variable that can be characterized by multivariate modeling techniques, leading to inaccurate inferences on the distribution of suitable habitat. In this paper, we examine the role of variable combining in mapping multiple dimensions of greater sage-grouse...

Using a large dataset compiled from studies over the years covering 23 tree species, we developed methods to estimate total and components (stem, bark, branch, and foliage) of aboveground live tree biomass. Missing components in the dataset were imputed using species-specific or generalized (species combined into softwood and hardwood groups) Dirichlet imputation. Geometric means of the imputed stem wood proportions were 8% and 9% higher than the observed geometric mean of stem wood proportions in softwood and hardwood species, respectively. For other components, the differences were...

The mixed severity fire regime of western Oregon forests creates a complex post-fire landscape mosaic with patches of low, moderate and high overstory tree mortality. Conversion of old-growth forests into plantations and post-fire salvage logging are widespread land uses that dramatically affect structure, biomass and carbon stocks. Few studies, however, have quantified the complex responses to wildfire and land management (i.e. logging and post-fire salvage logging) over long time periods. We quantified total aboveground biomass and composition in forest stands following low, moderate,...