Publications

Mangrove forests are highly productive tidal saline wetland ecosystems found along sheltered tropical and subtropical coasts. Ecologists have long assumed that climatic drivers (i.e., temperature and rainfall regimes) govern the global distribution, structure, and function of mangrove forests. However, data constraints have hindered the quantification of direct climate-mangrove linkages...

In sagebrush (Artemisia spp.) ecosystems, encroachment of pinyon (Pinus spp.) and juniper (Juniperus spp.; hereafter, “pinyon-juniper”) trees has increased dramatically since European settlement. Understanding the impacts of this encroachment on behavioral decisions, distributions, and population dynamics of greater sage-grouse (Centrocercus urophasianus) and other sagebrush obligate...

Almost half of Redwood National Park is comprised of second-growth forests characterized by high stand density, deficient redwood composition, and low understory biodiversity. Typical structure of young redwood stands impedes the recovery of old-growth conditions, such as dominance of redwood (Sequoia sempervirens (D. Don) Endl.), distinct canopy layers and diverse understory vegetation...

Conserving populations of long-lived birds of prey, characterized by a slow life-history (e.g., high survival and low reproductive output), requires a thorough understanding of how variation in their vital rates differentially affects population growth. Stochastic population modeling provides a framework for exploring variation in complex life histories to better understand how...

Avian influenza viruses (AIV) affect many species of birds including waterfowl and may persist in sediment in aquatic habitats. Sediment samples were collected from two areas representative of prime migration and overwintering waterfowl habitat in Dorchester County, Maryland in the fall and winter of 2013–2014. Samples were screened for the presence of AIV via reverse transcriptase...

Spatial heterogeneity in the environment induces variation in population demographic rates and dispersal patterns, which result in spatio‐temporal variation in density and gene flow. Unfortunately, applying theory to learn about the role of spatial structure on populations has been hindered by the lack of mechanistic spatial models and inability to make precise observations of population...

Managers of second-growth forests at Redwood National Park and the Bureau of Land Management’s Headwaters Forest Reserve encourage the development of late seral forest characteristics using mechanical thinning, where competing vegetation is removed to promote growth of residual trees. Yet the ability to quantify and reliably predict outcomes of treatments such as these is hindered by the...

The national network of weather surveillance radars (NEXRAD) detects birds in flight, and has proven to be a useful remote-sensing tool for ornithological study. We used data collected during Fall 2008 to 2014 by 16 NEXRAD and four terminal Doppler weather radars (TDWR) in the northeastern U.S. to map and study the spatial distribution of landbirds shortly after they leave daytime...

Ecosystems of Alaska are rain-, snow-, and ice-driven systems. Consequently, the status of water—liquid or solid—strongly in uences resources and the people using ecosystem services. This document examines changes in water dynamics, the resulting consequences for ecosystems and people, and management options for adapting to changing conditions. Changes in snow, ice, and water ripple...

The Mojave and Colorado deserts of southern California have been viewed as vast wilderness since early exploration and, until recently, were considered the most untrammeled among western landscapes in the contiguous lower 48 states (United States Department of Agriculture 1893; Leu et al. 2008). However, the factors that define desert wilderness—small human population, temperature...

This report summarizes the results for mtDNA and STR genotyping of 41 desert tortoise (Gopherus agassizii) DNA samples from opposite sides of the Coachella Valley: one sample from the west side at the Mesa wind energy facility in the Whitewater Hills and the other from the mouth of Cottonwood Canyon in Joshua Tree National Park, both within the boundaries of the Coachella Valley Multiple...

Food webs and associated trophic linkages among organisms are central themes in ecology that provide insight into the structure and function of ecosystems. In the deep sea, food webs rely on particulate flux raining from surface waters for energy (Klages et al. 2003), except for chemosynthetic communities, which rely on in situ production via chemosynthesis (Van Dover 2007). In general...