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Keyword: population dynamics

Breeding dispersal of Mexican Spotted Owls in the Sacramento Mountains, New Mexico

Publications Posted on: July 15, 2015
Dispersal is a key process influencing population dynamics and gene flow in species. Despite this, little is known about breeding dispersal in threatened Mexican Spotted Owls (Strix occidentalis lucida), here defined as movement of a non-juvenile owl between territories where it had the opportunity to breed.

Ecology of Mexican spotted owls in the Sacramento Mountains, New Mexico

Science Spotlights Posted on: May 20, 2015
RMRS scientists recently completed a 10 year study of a population of threatened Mexican spotted owls (Strix occidentalis lucida) in the Sacramento Mountains, New Mexico. This study evaluated demography, habitat use, and diet composition of spotted owls, as well as forest structure characteristic of owl habitat. We determined that most owl nests are located in wet mixed-conifer forests not greatly in need of ecological restoration.

Spatial dynamics of chinook salmon redds

Documents and Media Posted on: January 23, 2015
Most knowledge regarding the basic ecology of chinook salmon (Oncorhynchus tshawytscha) comes from studies in freshwater environments. Unfortunately, most of this knowledge is derived from studies conducted at relatively small spatial and temporal extents that provide a poor fit to the broader spatiotemporal themes that underlie most species conservation efforts.Document Type: Briefing Papers

Not all forests are disturbed equally: Population dynamics and resource selection of black-backed woodpeckers in the Black Hills, South Dakota

Publications Posted on: September 18, 2013
Western North American forests are shaped by natural disturbances, which are an important driver of habitat heterogeneity and species diversity. Wildfire and bark beetle infestations are of particular interest to resource managers because of their widespread occurrence and potential economic impacts.

Rapid increases and time-lagged declines in amphibian occupancy after wildfire

Publications Posted on: July 29, 2013
Climate change is expected to increase the frequency and severity of drought and wildfire. Aquatic and moisture-sensitive species, such as amphibians, may be particularly vulnerable to these modified disturbance regimes because large wildfires often occur during extended droughts and thus may compound environmental threats. However, understanding of the effects of wildfires on amphibians in forests with long fire-return intervals is limited.

Effects of temperature on development, survival and reproduction of insects: Experimental design, data analysis and modeling

Publications Posted on: October 05, 2012
The developmental response of insects to temperature is important in understanding the ecology of insect life histories. Temperature-dependent phenology models permit examination of the impacts of temperature on the geographical distributions, population dynamics and management of insects.

Non-target effects of broadleaf herbicide on a native perennial forb: a demographic framework for assessing and minimizing impacts

Publications Posted on: May 15, 2009
Invasive species are one of the leading threats to biodiversity worldwide. Therefore, chemical herbicides are increasingly used to control invasive plants in natural and semi-natural areas. Little is known about the non-target impacts of these chemicals on native species. We conducted an experiment to test the demographic effects of the herbicide picloram on a native dominant forb, arrowleaf balsamroot Balsamorhiza sagittata.

Responses of pond-breeding amphibians to wildfire: Short-term patterns in occupancy and colonization

Publications Posted on: September 26, 2008
Wildland fires are expected to become more frequent and severe in many ecosystems, potentially posing a threat to many sensitive species. We evaluated the effects of a large, stand-replacement wildfire on three species of pond-breeding amphibians by estimating changes in occupancy of breeding sites during the three years before and after the fire burned 42 of 83 previously surveyed wetlands.

Chondrilla juncea L.: Post-fire invasiveness in Artimesia tridentata communities of western north America

Publications Posted on: August 05, 2008
Chondrilla juncea L. (Asteraceae), an invasive Eurasian apomictic perennial weed that increases vegetatively and from seed, as spread from the Pacific Northwest, USA into Artemisia tridentata communities of the northern Great Basin. Over the last 150 years this region has been heavily impacted by excessive livestock grazing, the invasion of exotic annual grasses, primarily Bromus tectorum, and an increase in wildfire size and frequency.

Demographic and habitat requirements for conservation of bull trout

Publications Posted on: April 15, 2008
Elements in bull trout biology, population dynamics, habitat, and biotic interactions important to conservation of the species are identified. Bull trout appear to have more specific habitat requirements than other salmonids, but no critical thresholds of acceptable habitat condition were found. Size, temporal variation, and spatial distribution are likely to influence the stability of local and regional populations.