Treesearch

The Mongolian Plateau hosts two different governments: theMongolian People’sRepublicandthe Inner Mongolia AutonomousRegion, a provincial-level government of the People’sRepublic ofChina.The divergence between these governments haswidened in the past century,mostly due to a series of institutional changes that generated different socioeconomic and demographic trajectories.Due to its high latitude and altitude, the Plateau has been highly sensitive to the rapid changes in global and regional climates that have altered the spatial and temporal distributions of energy andwater.Based on a...

If a radiological incident such as a nuclear power plant accident, a radiological dispersal device, or detonation of an improvised nuclear device occurs, significant areas may be contaminated. Initial cleanup priorities would likely focus on populated areas, leaving the forested areas to pass several seasons where the overhead canopy materials would fall to the forest floor. In the event of a wildfire in a radionuclide-contaminated forest, some radionuclides would be emitted in the air while the rest would remain in the ash. This paper reports on a laboratory simulation study that examines...

Water conservation in nursery systems is an ever-increasing focus, yet there is relatively little guidance for growers producing seedlings intended for restoration regarding how practices such as subirrigation influence plant growth in the nursery and after outplanting. Our study investigated red-flowering currant (Ribes sanguineum Pursh) seedling development and early field performance using different fertilizer treatments under a subirrigation regime. Plants were fertilized with 1) incorporated organic fertilizer, 2) incorporated controlled-release fertilizer, 3) top-dressed controlled-re...

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...