Treesearch

The behavioral mechanisms by which predators encounter prey are poorly resolved. In particular, the extent to which predators engage in active search for prey versus incidentally encountering them has not been well studied in many systems and particularly not for neonate prey during the birth pulse. Parturition of many large herbivores occurs during a short and predictable temporal window in which young are highly vulnerable to predation. Our study aims to determine how a suite of carnivores responds to the seasonal pulse of newborn ungulates using contemporaneous global positioning system...

Hurricanes are expected to intensify throughout the 21st century, yet the impact of frequent major hurricanes on tropical ecosystems remains unknown. To investigate tropical forest damage and recovery under different hurricane regimes, we generate a suite of scenarios based on Coupled Model Intercomparison Project Phase 6 climate projections and increased hurricane recurrence and intensity for the Luquillo Experimental Forest, Puerto Rico. We then use the Ecosystem Demography model to predict changes in carbon stocks, forest structure and composition. Our results indicate that frequent...

There is a growing body of evidence that mesic tree species are increasing in importance across much of the eastern US. This increase is often observed in tandem with a decrease in the abundance and importance of species considered to be better adapted to disturbance and drier conditions (e.g., Quercus species). Concern over this transition is related to several factors, including the potential that this transition is self-reinforcing (termed “mesophication”), will result in decreased resiliency of forests to a variety of disturbances, and may negatively impact ecosystem functioning,...

Health benefits of outdoor recreation have been broadly demonstrated and land managers recognize the equity implications of providing safe and inclusive outdoor spaces. Data on public lands visitation and outdoor participation show that Hispanic recreationists are less likely to engage in outdoor leisure than White persons. Early studies of outdoor preferences of Hispanic persons identified a desire for large-group settings and social activities. To update our understanding of outdoor recreation needs, preferences, and constraints, we collaborated with a Latinx organization in Portland,...

Commercial timber harvest sites in Alaska were studied between 2016 and 2019 to estimate growing-stock removals, characterize current tree utilization, characterize logging operations, and assist with estimating the amount of woody biomass left onsite after harvesting. Sample logging sites were selected within major geographic regions in proportion to 5-year timber harvest volumes. A two-stage sampling method (felled trees clustered within logging sites) was used to compute state-level utilization factors. Results indicated that for every 1,000 ft3 delivered to the mill, harvesting removed...

Large western redcedar (Thuja plicata) and yellow-cedar (Callitropsis nootkatensis) trees have been prominent in many Tlingit, Haida, and Tsimshian Alaska Native traditions for 5,000 years. Today, these southeast Alaska tribes harvest logs from their historical territories within the Tongass National Forest. Cedars that are more than 450 years old provide logs for totem poles and canoes as well as bark for traditional weaving. Forest Service researchers Adelaide Johnson and Lee Cerveny worked with research collaborators, indigenous community leaders, tribal members, prominent carvers, and...

Many forests of the western United States have undergone over one hundred years of anthropogenic impacts that have led to increased tree density, homogenization in forest structure, and accumulation of woody material, which combined with a changing climate pose threats to valued social and ecological features. In California, recent waves of tree mortality and unprecedented large and destructive fires have led to rising concerns about the impact of these disturbances on biodiversity and how forest management actions can mitigate negative impacts. To better understand the degree to which...

Wildfire dynamics are changing around the world and understanding their effects on ecological communities and landscapes is urgent and important. We report detailed food webs for unburned, low-to-moderate and high severity burned habitats three years post-fire in the Eldorado National Forest, California. The cumulative cross-habitat food web contains 3,084 ontogenetic stages (nodes) or plant parts comprising 849 species (including 107 primary producers, 634 invertebrates, 94 vertebrates). There were 178,655 trophic interactions between these nodes. We provide information on taxonomy, body...

The success of space-based forest defoliation monitoring beyond thematic classification hinges on the ability to link units of continuous foliar change with associated units of spectral or vegetation index change across different systems. To explore this, we used multi-temporal Landsat sensor data with respect to three defoliation metrics (shoot-based estimates (%), frass biomass (kg⋅ha−1), and proportion of foliar loss) across three different forest systems in the United States. While shoot-based defoliation was measured in the field, the later two defoliation metrics were estimated based...