Treesearch

Macroinvertebrate community taxonomic and trait structure showed consistent differences between riffles and pools across 12 headwater streams in the Sierra Nevada (California) even as flows varied from wet to dry years and between seasons. Densities of Ephemeroptera, Plecoptera, Trichoptera, Elmidae, Orthocladiinae and Diamesinae midges, and mites were greater in riffles, whereas Tanypodinae, Chironominae, Sialis, and Pisidiumwere more abundant in pools. Pools had higher densities but estimated biomass was greater in riffles. Collector-gatherer and micropredator abundances were greater in...

Many species of wildlife require cavities in trees as locations for refuge or reproduction. In forests where the availability of cavities has been reduced, artificial cavities may provide surrogate locations. Artificial cavities are typically created using boxes and artificial cavity research has traditionally focused primarily on birds. However, there are numerous cavity‐dependent species of mammals that are of regional and global conservation concern, such as the Humboldt marten (Martes caurina humboldtensis). Martens (Martesspp.) are small mustelids that often use cavities for daily...

Quantifying reproductive parameters is essential for developing effective conservation plans for species of concern; however, studying reproduction in wild settings can be challenging and local data are frequently unavailable. The fisher (Pekania pennanti) is an elusive forest-dwelling carnivore of conservation concern that occurs across much of boreal North America and reaches the southernmost limit of its distribution in the southern Sierra Nevada (SSN) in California. Data on fisher reproduction in this region are limited and applicability of parameters from other areas is uncertain. To...

The Sierra Nevada is one of the most striking features of the state of California, extending from the southern Cascade Mountains in the north to the Tehachapi Mountains and Mojave Desert 620 km (435 mi) to the south (Map14.1). The Central Valley forms the western boundary of the Sierra Nevada bioregion, and the Great Basin is on the east. The bioregion includes the central mountains and foothills of the Sierra Nevada Section and the Sierra Nevada Foothills Section of Miles and Goudey (1997). The area of the bioregion is 69,560 km2 (26,442 mi2), approximately 17% of the state. Significant...

Oak woodlands are dependent on frequent fire to maintain the low stem density and diverse understories that typify these ecosystems. Without this recurrent disturbance, fire-sensitive conifer competitors encroach on oaks, reducing their vigor, and diminishing habitat quality. In fire-excluded oak woodlands, stand-replacing wildfire can trigger shifts in canopy dominance from seed-generated conifers to oaks, which are capable of vigorous sprouting following topkill. We examined the occurrence and sprouting dynamics of California black oak (Quercus kelloggiiNewb.) following repeated wildfires...

Barred owls (Strix varia) have reached high densities within the range of the northern spotted owl (S. occidentalis caurina) and are rapidly increasing in number within the range of the California spotted owl (S. o. occidentalis). Encroaching populations of barred owls pose a significant competitive threat to the viability of both spotted owl subspecies in California. In response, the Director of the California Department of Fish and Wildlife (CDFW) convened the California Barred Owl Science Team (BOST) to identify and address the threat posed by barred owls to spotted owls in California....

Prescribed fire, intentionally ignited low-intensity fires, and managed wildfires—wildfires that are allowed to burn for land management benefit—could be used as a land management tool to create forests that are resilient to wildland fire. This could lead to fewer large catastrophic wildfires in the future. However, we must consider the public health impacts of the smoke that is emitted from wildland and prescribed fire. The objective of this synthesis is to examine the differences in ambient community-level exposures to particulate matter (PM2.5) from smoke in the United States in...

Aim To determine the role of regional forcing on plot‐level species diversity and composition, and to quantify the relative importance of biogeographical and climatic factors in explaining woody plant diversity and composition at the local‐, island‐ and archipelago‐scale. Location Forty‐one tropical islands of the Indo‐Pacific region from Madagascar to Hawai‘i Island. Methods We analysed the diversity and composition of tropical woody plant communities located across 113 plots, 41 islands and 19 archipelagos. We used generalized linear mixed‐effects models and generalized dissimilarity...

Nonnative invasive herbivores can create complex biotic interactions by differentially feeding on native and nonnative invasive plant species. The herbivores may act as enemies of nonnative plants and prevent them from becoming invasive, or they may facilitate invasion by having a greater negative impact on native plants compared with nonnative plants. It is also possible that within the same ecosystem nonnative herbivores could either facilitate or inhibit invasion under different abiotic or biotic conditions. In this study we experimentally investigated how abiotic (soil nutrients) and...

One of many ecosystem services essential to land management is carbon regulation, but presence of invasive species can influence carbon (C) in undesirable ways. Here we discuss early results of C accumulation from the Liko Nā Pilina hybrid wet forest restoration experiment. The focus of our project is to deliberately increase C storage through a functional trait-based approach to restoration. By choosing plant species mixes with specific functional trait values, a novel ecosystem can be assembled that supports desired ecosystem services such as C regulation. We designed species mixtures...