Treesearch

The robust dispersal capability of the coyote (Canis latrans) would suggest a pattern of widespread gene flow across North America, yet historical legacies, dispersal barriers, and habitat affinities may produce or reinforce genetic structure. In the northeastern United States, some coyotes carry genetic signatures from past hybridization events with eastern wolves (C. lupus lycaon). These so-called "coywolves" may have differential predation or competitive success compared with the western origin coyotes with whom they share the contemporary landscape. We sampled coyote populations from...

The science of urban ecology has increasingly grappled with the long-term ramifications of a globally urbanized planet and the impacts on biodiversity. Some researchers have suggested that places with high species diversity in cities simply reflect an extinction debt of populations that are doomed to extinction but have not yet disappeared. The longitudinal studies conducted to date have found species composition shifting with urbanization but have not always documented continued species extirpations post-urbanization. We used long-term monitoring data on birds from the greater metropolitan...

We describe an observation of Zenaida macroura (Mourning Dove) nesting atop an active Dulus dominicus (Palmchat) nest in an urban park located in the Colonial Zone of Santo Domingo, Dominican Republic. To our knowledge, this is the first published observation of mutual nest placement and simultaneous nesting by these 2 species. We provide natural history information about both species, the possibility of a symbiotic relationship between them, and describe the implications for urban bird conservation.

In the Appalachian Mountains of eastern North America, mountain laurel (Kalmia latifolia) thickets in mixed-oak (Quercus spp.) stands can lead to hazardous fuel conditions, forest regeneration problems, and possible forest health concerns. Generally, land managers use mechanical means or prescribed fire to control mountain laurel thickets, but these treatments are expensive, dangerous to implement, or have short-term effectiveness. From 2012 to 2016, we compared the effectiveness of three herbicides applied as broadcast foliar treatments at varying rates and in different months for...

Humans have dramatically increased atmospheric nitrogen (N) deposition globally. At the coarsest resolution, N deposition is correlated with shifts from ectomycorrhizal (EcM) to arbuscular mycorrhizal (AM) tree dominance. At finer resolution, ectomycorrhizal fungal (EcMF) and arbuscular mycorrhizal fungal (AMF) communities respond strongly to long-term N deposition with the disappearance of key taxa. Conifer-associated EcMF are more sensitive than other EcMF, with current estimates of critical loads at 5-6 kg ha-1 yr-1 for the former and 10-20 kg ha-1 yr-1 for the latter. Where loads are...

The increase in compounding disturbances, such as "hotter droughts" coupled with insect outbreaks, has significant impacts on the integrity of forested ecosystems and their subsequent management for important ecosystem services and multiple-use objectives. In the Southern Sierra Nevada, years of severe drought have resulted in unprecedented tree mortality across this mountainous landscape. Additionally, past land management practices, including fire suppression, have led to overly stocked, homogenous forest stand structures, dominated by small diameter, shade-tolerant and fire-intolerant...

In this study, the Flexible Particle (FLEXPART)-WRF, a Lagrangian particle dispersion model, is employed to simulate pollutant dispersion in and near the LehighGap, a gap in a prominent ridgeline in eastern Pennsylvania. FLEXPART-WRF is used to evaluate the diagnostic value of the ventilation index (VI), an index that describes the potential for smoke or other pollutants to ventilate away from a source, for indicating dispersion potential in complex terrain. Little is known about the effectiveness of the ventilation index in diagnosing dispersion potential in complex terrain. The modeling...

This report is based on the final version of the Humboldt marten (Martes caurina humboldtensis) conservation assessment and strategy submitted on September 30, 2017 by the Humboldt Marten Conservation Group. This assessment and strategy was developed in response to the decline of the Humboldt marten throughout most of its historical range in California and Oregon. The first four chapters synthesize the state of the knowledge on the Humboldt marten and relevant ecological and management aspects of the forest habitats it occupies. The final chapter identifies overall conservation goals,...

Surface mining in the Appalachian region (USA) converts large areas of mature forest to early successional habitat. This shift in landscape structure has the potential to reduce habitat availability and suitability for forest-dwelling songbirds by reducing and fragmenting mature forest, but also to increase habitat availability for grassland- and shrubland-associated songbirds. We examined the influence of mountaintop mining/valley fill (MTMVF) reclamation habitats (grassland, shrubland, and remnant forest) on songbird community composition and abundance at three former MTMVF mines in...

When estimating tree-level biomass and carbon, it is common practice to develop generalized models across numerous species and large spatial extents. However, sampling efforts are generally incomplete and trees are not randomly selected. In this analysis, of the more than 1,000 biomass-related articles that were reviewed, trees were destructively sampled in over 300 studies to estimate biomass in the United States. Studies were summarized and past sampling efforts were explored to illuminate where the largest data gaps occurred in terms of tree components sampled, tree size, tree form,...