Treesearch

Ungulate carrion supports an unusual canine-corvid-eagle winter scavenging guild in northern Arizona. To evaluate the effect of location and habitat on carcass use and longevity, between December 1996 and April 2008 we recorded 870 observations of Bald Eagles (Haliaeetus leucocephalus), Common Ravens (Corvus corax) and coyotes (Canis latrans) scavenging 123 ungulate carcasses: 103 elk (Cervus canadensis), 12 mule deer (Odocoileus hemionus), seven pronghorn antelope (Antilocapra americana), and one domestic cow (Bos taurus). Our temporal metric for measuring carcass longevity and scavenger...

Coastal wetlands represent an ecotone between ocean and terrestrial ecosystems, providing important services, including flood mitigation, fresh water supply, erosion control, carbon sequestration, and wildlife habitat. The environmental setting of a wetland and the hydrological connectivity between a wetland and adjacent terrestrial and aquatic systems together determine wetland hydrology. Yet little is known about regional‐scale hydrological interactions among uplands, coastal wetlands, and coastal processes, such as tides, sea level rise, and saltwater intrusion, which together control...

Ecological communities often exhibit greater resistance to biological invasions when these communities consist of species that are not closely related. The effective size of this resistance, however, varies geographically. Here we investigate the drivers of this heterogeneity in the context of known contributions of native trees to the resistance of forests in the eastern United States of America to plant invasions. Using 42,626 spatially referenced forest community observations, we quantified spatial heterogeneity in relationships between evolutionary relatedness amongst native trees and...

Research Highlights: We demonstrate a macroscale framework combining an invasibility model with forest inventory data, and evaluate regional forest exposure to harmful invasive plants under different types of forest protection. Background and Objectives: Protected areas are a fundamental component of natural resource conservation. The exposure of protected forests to invasive plants can impede achievement of conservation goals, and the effectiveness of protection for limiting forest invasions is uncertain. We conducted a macroscale assessment of the exposure of protected and unprotected...

Increasing the evolutionary potential of restored populations has become a viable objective of restoration activities. Choosing plant materials genetically adapted to the restoration environment is critical for success, and phenotypic plasticity may also contribute to establishment and persistence in disturbed environments. To select seed sources for restoration informed by plasticity, we must answer the question: Do some source environments produce more plastic genotypes than others? Using a dataset of maternal families from 130 western US source populations of the perennial bunchgrass...

Recent developments in remote sensing (RS) technology have made several sources of auxiliary data available to support forest inventories. Thus, a pertinent question is how different sources of RS data should be combined with field data to make inventories cost-efficient. Hierarchical model-based estimation has been proposed as a promising way of combining: (i) wall-to-wall optical data that are only weakly correlated with forest structure; (ii) a discontinuous sample of active RS data that are more strongly correlated with structure; and (iii) a sparse sample of field data. Model predictio...

Recent extensive forest mortality and subsequent salvage logging may threaten the water supply from headwater catchments in western North America. Land managers confronting current insect outbreaks and projected increases in forest disturbance require information about the potential water quality consequences of these changes. This study is a hillslope-scale evaluation of soil N and C leaching in lodgepole pine forests that have experienced 80% overstory tree mortality. I measured extractable inorganic and ion resin exchangeable-N forms, in situ net mineralization and nitrification, and...

Disturbance is central to maintaining diversity in forest ecosystems. In the dry forests of the western United States, over a century of fire exclusion has altered the fire regimes of these forests, resulting in high fuel loads and a loss of plant diversity. Mechanical thinning and prescribed fire are widely used to restore structural complexity and species diversity in many western U.S. forests. While studies have shown that the reintroduction of fire into these forests initially promotes plant diversity, there is limited information on the persistence of this effect. We evaluated the...

Wildland fire is a significant and growing threat to communities and natural resources on Hawaii and the U.S.- affiliated Pacific Islands, including Wildland fire is a significant and growing threat to communities and natural resources on Hawaii and the U.S.- affiliated Pacific Islands. Collaborative approaches to fire management are critical because multiple interacting factors --including climate, ecosystem composition, land use history, social-ecological impacts, and cultural perceptions --create highly complex problems. However, identifying effective strategies to promote dialogue and...

Great Basin bristlecone pine, Pinus longaeva (GBBP), is one of the longest-lived, nonclonal organisms on Earth and is also one of the most highly fragmented high-elevation conifer species. Great basin bristlecone pine ecosystems contain many biodiversity “hot spots” with a high degree of species endemism. Throughout the Great Basin, GBBP communities are being threatened by changing disturbance regimes, invasive species, and climate change. The loss of GBBP can detrimentally impact biodiversity and valuable resources including wildlife habitat, watershed and soil protection, aesthetics, and...