A5040347910- Fire effects on ecosystems
- Ecology and Vegetation Dynamics Studies
- Forest Insect Ecology and Management
- Forest ecology and management
- Tree-ring climate responses
- Forest Ecology and Biodiversity Studies
- Animal Ecology and Behavior Studies
- Plant and animal studies
- Rangeland and Wildlife Management
- Avian ecology and behavior
- Botany, Ecology, and Taxonomy Studies
- Wildlife Ecology and Conservation
- Forest Management and Policy
- Genetic diversity and population structure
- Species Distribution and Climate Change
- Plant Water Relations and Carbon Dynamics
- Plant Taxonomy and Phylogenetics
- Animal Behavior and Reproduction
- Genomics and Phylogenetic Studies
- Yeasts and Rust Fungi Studies
- Botany and Plant Ecology Studies
- Seed Germination and Physiology
- Animal Vocal Communication and Behavior
- Archaeology and Natural History
- Lichen and fungal ecology
University of Colorado Denver
2015-2025
Ecological Society of America
2019
Rocky Mountain Research (United States)
2017
United States Department of Agriculture
2017
University of Colorado Boulder
1989-1996
Colorado State University
1980-1987
University of California, Santa Barbara
1975
Identification of microsatellites, or simple sequence repeats (SSRs), can be a time-consuming and costly investment requiring enrichment, cloning, sequencing candidate loci. Recently, however, high throughput (with without prior enrichment for specific SSR loci) has been utilized to identify The direct "Seq-to-SSR" approach an advantage over enrichment-based strategies in that it does not require priori selection particular motifs, knowledge genomic content. It more expensive per locus...
(1) Clark's nutcrackers (Nucifraga columbiana) store a mean of only 3.7 whitebark pine (Pinus albicaulis) seeds per cache, which reduces competition for moisture and space. The depth at are stored, 2.0 cm, is compatible with germination requirements, many sites selected appear suitable seed germination. (2) One nutcracker stores about 32 000 subalpine elevations each year, represent 3-5 times its energetic requirements. Although parent feed stored to juveniles, in some years there probably...
Summary Eight white pine species are widely distributed among the forests of western Canada and United States. The different forest communities with these contribute biodiversity to landscape. trees themselves provide various ecosystem services, including wildlife habitat watershed protection. White range in elevation from lower upper treeline, successional stage seral climax, stand type krummholz closed‐canopy forest. Many moderately strongly fire‐dependent for regeneration; several extreme...
The Clark's Nutcracker (Nucifraga columbiana) stores conifer seeds in the late summer and fall of each year. During winter spring, from buried caches are major food nutcrackers their young. A bird must find more than a thousand seed alternative means by which may locate (1) memory cache site (2) trial error search. While searching for stored seeds, makes series prod holes with its bill. hole was recovered is usually distinguished pile broken coats. This allows an estimate nutcracker's...
Although the ecological dynamics of alpine treeline ecotone are influenced by climate, it is an imperfect indicator climate change. Mechanistic processes that shape ecotone—seed rain, seed germination, seedling establishment and subsequent tree growth form, or, conversely dieback—depend on microsite patterns. Growth forms affect wind snow, so develop positive negative feedback loops create these microsites. As a result, complex landscape patterns generated at multiple spatial scales....
Human-caused disruptions to seed-dispersal mutualisms increase the extinction risk for both plant and animal species. Large-seeded plants can be particularly vulnerable due highly specialized dispersal systems no compensatory regeneration mechanisms. Whitebark pine (Pinus albicaulis), a keystone subalpine species, obligately depends upon Clark's Nutcracker (Nucifraga columbiana) of its large, wingless seeds. Nutcracker, facultative mutualist with whitebark pine, is sensitive rates energy...
Whitebark pine (Pinus albicaulis) seeds are dispersed by Clark's Nutcracker (Nucifraga columbiana), a bird that makes caches under 2–3 cm of soil. Cached may delay germination for one or more years in part because underdeveloped embryos at the time seed dispersal. Consequently, whitebark show soil bank strategy is unique among pines (Pinaceae, Pinus). From 1990 to 1995 we studied natural regeneration following 1988 Yellowstone fires determine: (1) whether typically exhibits delayed and, if...
Whitebark pine (Pinus albicaulis), an important treeline conifer in northern Montana, is considered both a keystone and foundation species high-elevation ecosystems. The introduced fungal pathogen Cronartium ribicola, which causes white blister rust, has resulted severe declines whitebark subalpine forest communities throughout the Rockies during past decades. However, prevalence of rust within alpine community its impact remain to be determined. We gathered field data on infection incidence...
The potential impact of invasive forest pathogens on alpine treeline dynamics has not previously been considered. Whitebark pine (Pinus albicaulis), a foundation and keystone species subalpine forests major component in the northern Rocky Mountains United States southern Canada, is infected nearly range-wide by exotic pathogen Cronartium ribicola, which causes white blister rust. A Mountains, whitebark initiates tree islands eastern slope northwestern Montana more than any other conifer...
Abstract In Marin County, California, the dialect populations of Zonotrichia leucophrys nuttalli are contiguous, and there is little mixing. The possible importance male-male interactions in preventing mixing was tested with song-playback experiments. Males Limantour were presented dialect, Drake or Buzzy dialects (neighboring), Clear (distant). From previous work, we predicted that males would respond equal more aggression to songs immediately neighboring comparison their own but at lower...
Background Accurately quantifying key interactions between species is important for developing effective recovery strategies threatened and endangered species. Whitebark pine (Pinus albicaulis), a candidate listing under the Endangered Species Act, depends on Clark's nutcracker (Nucifraga columbiana) seed dispersal. As whitebark succumbs to exotic disease mountain beetles (Dendroctonus ponderosae), cone production declines, nutcrackers visit stands less frequently, reducing probability of...
Whitebark pine (Pinus albicaulis) has the largest and most northerly distribution of any white (Subgenus Strobus) in North America, encompassing 18° latitude 21° longitude western mountains. Within this broad range, however, whitebark occurs within a narrow elevational zone, including upper subalpine treeline forests, functions generally as an important keystone foundation species. In Rocky Mountains, facilitates development krummholz conifer communities alpine-treeline ecotone (ATE), thus...
Abstract Many forest species are adapted to long-interval, high-severity fires, but the intervals between severe fires decreasing with changes in climate, land use, and biological invasions. Although effects of changing fire regimes on some important recovery processes have previously been considered, consequences for dispersal propagules (plant seeds fungal spores) communities not. We characterize three mechanisms by which disrupt propagule mesic temperate, boreal, high-elevation forests:...
Where wild populations of gray wolves ( Canis lupus ) occur in North America, common ravens Corvus corax and, western regions, black-billed magpies Pica hudsonia (Family Corvidae), show up quickly at wolf kills and scavenge carcasses, often feeding near wolves. Ravens also visit enclosures sanctuaries Colorado, USA, attempt to take food from wolves, but there is no information regarding how they obtain or are injured killed. Working the Colorado Wolf Wildlife Center, Divide, we asked whether...
We tested the hypotheses that white pine blister rust ( Cronartium ribicola J.C. Fisch.) damage in whitebark Pinus albicaulis Engelm.) stands leads to reduced (1) seed cone density, (2) predispersal survival, and (3) likelihood of Clark’s Nutcracker Nucifraga columbiana (Wilson, 1811)) dispersal. gathered data from two sets paired forest sites Bitterroot Mountains eastern Idaho western Montana were similar topography, canopy structure, tree species composition, successional stage, but...
Whitebark pine (Pinus albicaulis Engelm.) is an ecologically important subalpine and treeline forest tree of the western U.S. Canada. It categorized as endangered by IUCN Canada under Species at Risk Act was recently proposed for listing in threatened Endangered Act. populations are declining nearly rangewide primarily from spread intensification Cronartium ribicola J.C. Fisch., exotic, invasive pathogen that causes white blister rust (WPBR); recent, large-scale outbreaks mountain beetles...
In the northern Rocky Mountains, whitebark pine ( Pinus albicaulis ) is rapidly declining as a result of previous fire exclusion policies, mountain beetle Dendroctonus ponderosae outbreaks, and white blister rust Cronartium ribicola ). Blister potentially most destructive agent, killing seedlings, cone‐bearing branches, and, eventually, mature trees. We examined densities regeneration incidence severity blister‐rust infection seedlings saplings in 25‐year‐old Sundance Burn Selkirk Range...