Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Algal (1)
- Benthic (1)
- Biocomplexity (1)
- Community ecology (1)
- Desert ecosystem (1)
-
- Experimental manipulation (1)
- Hydrologic (1)
- Individual distribution (1)
- Joshua trees (1)
- Long term (1)
- Metabolic ecology (1)
- Mountain stream (1)
- Neutral theory (1)
- Nitrate (1)
- Nitrogen (1)
- Removal (1)
- Sanak island (1)
- Selective herbivory (1)
- Species abundance (1)
- Stream (1)
- Tropical forests (1)
- Western gulf (1)
- Woodrat (1)
- Zero-sum dynamics (1)
Articles 1 - 12 of 12
Full-Text Articles in Life Sciences
Scared Sick? Predator-Pathogen Facilitation Enhances The Exploitation Of A Shared Resource, Ricardo A. Ramirez, W E. Snyder
Scared Sick? Predator-Pathogen Facilitation Enhances The Exploitation Of A Shared Resource, Ricardo A. Ramirez, W E. Snyder
Biology Faculty Publications
Resource use generally increases with greater consumer diversity, an effect often attributed to resource partitioning. Pathogens and predators are two classes of consumer that exhibit differences in ecologically important traits (e.g., size, resource acquisition strategy, foraging location) that could lead to complementary effects on shared prey/hosts. To examine this possibility, we manipulated diversity among a community of predators and pathogens that together attack an herbivorous beetle, Leptinotarsa decemlineata, and measured resulting effects on herbivore suppression and resulting plant damage. We found that herbivore mortality increased, and plant damage decreased, when more natural enemy species were present. However, closer examination revealed …
Differences In Nitrate Uptakeamong Benthic Algal Assemblages In A Mountain Stream, Michelle A. Baker, G. De Guzman
Differences In Nitrate Uptakeamong Benthic Algal Assemblages In A Mountain Stream, Michelle A. Baker, G. De Guzman
Biology Faculty Publications
We evaluated how benthic algal assemblages that vary in composition, richness, and other diversity metrics remove NO 3 -N from the water column of a mountain stream. Ecological theory and empirical studies suggest that ecosystem process rates should increase as richness increases because of niche separation or activity of dominant taxa. Accordingly, we predicted that algal assemblages with highest richness would show the highest rates of NO 3 -N uptake. To test this prediction, we transplanted 225 rocks representing 3 patch types (green, yellow, and brown) that differed macroscopically in algal composition from a lake outflow stream to a lake …
Hydrologic Control Of Nitrogenremoval, Storage And Export In A Mountain Stream, R. O. Hall Jr., Michelle A. Baker, C. D. Arp, B. J. Koch
Hydrologic Control Of Nitrogenremoval, Storage And Export In A Mountain Stream, R. O. Hall Jr., Michelle A. Baker, C. D. Arp, B. J. Koch
Biology Faculty Publications
Nutrient cycling and export in streams and rivers should vary with flow regime, yet most studies of stream nutrient transformation do not include hydrologic variability. We used a stable isotope tracer of nitrogen (15N) to measure nitrate (NO3-) uptake, storage, and export in a mountain stream, Spring Creek, Idaho, U.S.A. We conducted two tracer tests of 2-week duration during snowmelt and baseflow. Dissolved and particulate forms of 15N were monitored over three seasons to test the hypothesis that stream N cycling would be dominated by export during floods, and storage during low flow. Floods …
Taking Species Abundance Distributions Beyond Individuals, H. Morlon, Ethan P. White, R. S. Etienne, J. L. Green, A. Ostling, D. Alonso, B. J. Enquist, F. He, A. H. Hurlbert, A. E. Magurran, B. A. Maurer, B. J. Mcgill, H. Olff, D. Storch, T. Zillio
Taking Species Abundance Distributions Beyond Individuals, H. Morlon, Ethan P. White, R. S. Etienne, J. L. Green, A. Ostling, D. Alonso, B. J. Enquist, F. He, A. H. Hurlbert, A. E. Magurran, B. A. Maurer, B. J. Mcgill, H. Olff, D. Storch, T. Zillio
Biology Faculty Publications
The species abundance distribution is one of the few “universal” patterns in ecology. Research on this fundamental distribution has been focused to the study of numerical counts, irrespective of the traits of individuals. Here we show that considering a set of Generalized Species Abundance Distributions (GSADs) that encompass several abundance measures, specifically numerical abundance, biomass and resource use can provide novel insights into organizational forces at play in ecological communities. We first leverage a comprehensive dataset to investigate the similarity and difference between GSADs. We then use classical probability theory and allometric scaling laws to explore theoretical linkages among GSADs …
Changes In A Tropical Forest Support Metabolic Zero-Sum Dynamics, S.K. Morgan Ernest, Ethan P. White, J. H. Brown
Changes In A Tropical Forest Support Metabolic Zero-Sum Dynamics, S.K. Morgan Ernest, Ethan P. White, J. H. Brown
Biology Faculty Publications
Major shifts in many ecosystem-level properties of tropical forests have been observed, but the processes driving these changes are poorly understood. Over the past two decades, the forest on Barro Colorado Island, Panama (BCI) exhibited a 20% decrease in the number of trees and a 10% increase in average tree diameter. Here we show that these changes are consistent with a zero-sum constraint operating in this forest. Zero-sum constraints result when the total resource use of an ecosystem is limited by available resources. This causes increases in resource use by some groups of organisms to be compensated for by decreases …
Long-Term Monitoring And Experimentalmanipulation Of A Chihuahuan Desert Ecosystem Near Portal, Arizona, Usa, S.K. Morgan Ernest, T. J. Valone, J. H. Brown
Long-Term Monitoring And Experimentalmanipulation Of A Chihuahuan Desert Ecosystem Near Portal, Arizona, Usa, S.K. Morgan Ernest, T. J. Valone, J. H. Brown
Biology Faculty Publications
Desert ecosystems have long served as model systems in the study of ecological concepts (e.g., competition, resource pulses, top-down/bottom-up dynamics). However, the inherent variability of resource availability in deserts, and hence consumer dynamics, can also make them challenging ecosystems to understand. Study of a Chihuahuan desert ecosystem near Portal, Arizona, USA, began in 1977. At this site, 24 experimental plots were established in 1977 and divided among controls and experimental manipulations. Experimental manipulations over the years include removal of all or some rodent species, all or some ants, seed additions, and various alterations of the annual plant community. While some …
An Introduction To The Biocomplexity Of Sanak Island, Western Gulf Alaska, Hd G. Maschner, M Betts, J Cornell, B Finney, J A. Dunne, Nancy J. Huntly, J W. Jordan, N Misarti, K L. Reedy-Maschner, R Russell
An Introduction To The Biocomplexity Of Sanak Island, Western Gulf Alaska, Hd G. Maschner, M Betts, J Cornell, B Finney, J A. Dunne, Nancy J. Huntly, J W. Jordan, N Misarti, K L. Reedy-Maschner, R Russell
Biology Faculty Publications
The Sanak Biocomplexity Project is a transdisciplinary research effort focused on a small island archipelago 50 km south of the Alaska Peninsula in the western Gulf of Alaska. This team of archaeologists, terrestrial ecologists, social anthropologists, intertidal ecologists, geologists, oceanographers, paleoecologists, and modelers is seeking to understanding the role of the ancient, historic, and modern Aleut in the structure and functioning of local and regional ecosystems. Using techniques ranging from systematic surveys to stable isotope chemistry, long-term shifts in social dynamics and ecosystem structure are present in the context of changing climatic regimes and human impacts. This paper presents a …
Conservation Of Selection On Matk Following An Ancient Loss Of Its Flanking Intron, A. M. Duffy, S. A. Kelchner, Paul G. Wolf
Conservation Of Selection On Matk Following An Ancient Loss Of Its Flanking Intron, A. M. Duffy, S. A. Kelchner, Paul G. Wolf
Biology Faculty Publications
The chloroplast gene trnK and its associated group II intron appear to be absent in a large and ancient clade that includes nearly 90% of fern species. However, the maturase protein encoded within the intron (matK) is still present and located on the boundary of a large-scale inversion. We surveyed the chloroplast genome sequence of clade-member Adiantum capillus-veneris for evidence of a still present but fragmented trnK intron. Lack of signature structural domains and sequence motifs in the genome indicate loss of the trnK intron through degradation in an ancestor of the clade. In plants, matK preferentially catalyzes splicing of …
The Taxonomic Designation Of Eriogonum Corymbosum Var. Nilesii (Polygonaceae) Is Supported By Aflp And Cpdna Analyses, M. W. Ellis, J. M. Roper, R. Gainer, J. P. Der, Paul G. Wolf
The Taxonomic Designation Of Eriogonum Corymbosum Var. Nilesii (Polygonaceae) Is Supported By Aflp And Cpdna Analyses, M. W. Ellis, J. M. Roper, R. Gainer, J. P. Der, Paul G. Wolf
Biology Faculty Publications
We examined populations of perennial, shrubby buckwheats in the Eriogonum corymbosum complex and related Eriogonum species in the subgenus Eucycla, to assess genetic affiliations of the recently named E. corymbosum var. nilesii. The known populations of this varietyare all located in Clark County, Nevada, U. S. A. We compared AFLP profiles and chloroplast DNA sequences of plants sampled from populations of E. corymbosum var. nilesii with those of plants representing other E. corymbosum varieties and related Eriogonum species from Colorado,Utah, northern Arizona, and northern New Mexico. We found evidence of genetic cohesion among the Clark County populations as well astheir …
Global Chloroplast Phylogeny And Biogeography Of Bracken (Pteridium: Dennstaedtiaceae), J. P. Der, J. A. Thomson, J. K. Stratford, Paul G. Wolf
Global Chloroplast Phylogeny And Biogeography Of Bracken (Pteridium: Dennstaedtiaceae), J. P. Der, J. A. Thomson, J. K. Stratford, Paul G. Wolf
Biology Faculty Publications
Bracken ferns (genus Pteridium) represent an ancient species complex with a natural worldwide distribution. Pteridium has historically been treated as comprising a single species, but recent treatments have recognized several related species. Phenotypic plasticity, geographically structured morphological variation, and geographically biased sampling have all contributed to taxonomic confusion in the genus. We sampled bracken specimens worldwide and used variable regions of the chloroplast genome to investigate phylogeography and reticulate evolution within the genus. Our results distinguish two major clades within Pteridium, a primarily northern hemisphere Laurasian/African clade, which includes all taxa currently assigned to P. aquilinum, and a primarily southern …
Global Chloroplast Phylogeny And Biogeography Of Bracken (Pteridium: Dennstaedtiaceae), Joshua P. Der, J. A. Thomson, J. K. Stratford, Paul G. Wolf
Global Chloroplast Phylogeny And Biogeography Of Bracken (Pteridium: Dennstaedtiaceae), Joshua P. Der, J. A. Thomson, J. K. Stratford, Paul G. Wolf
Biology Faculty Publications
Bracken ferns (genus Pteridium ) represent an ancient species complex with a natural worldwide distribution. Pteridium has historically been treated as comprising a single species, but recent treatments have recognized several related species. Phenotypic plasticity, geographically structured morphological variation, and geographically biased sampling have all contributed to taxonomic confusion in the genus. We sampled bracken specimens worldwide and used variable regions of the chloroplast genome to investigate phylogeography and reticulate evolution within the genus. Our results distinguish two major clades within Pteridium , a primarily northern hemisphere Laurasian/African clade, which includes all taxa currently assigned to P. aquilinum , and …
Selective Herbivory By The Woodrat (Neotoma Lepida) On Joshua Trees (Yucca Brevifolia), M P. Stanford, Nancy J. Huntly
Selective Herbivory By The Woodrat (Neotoma Lepida) On Joshua Trees (Yucca Brevifolia), M P. Stanford, Nancy J. Huntly
Biology Faculty Publications
We studied herbivory by the desert woodrat (Neotoma lepida) on Joshua trees (Yucca brevifolia) in the Mojave Desert to determine whether N. lepida fed selectively based on leaf nitrogen content. We measured leaf nitrogen content and the location and amount of herbivory by woodrats on Y. brevifolia trees in southwestern Utah, USA. Neotoma lepida removed the outer tips of leaves (1/3 to 2/3 of total leaf length) but left leaf bases, which had lower nitrogen content, uneaten. Herbivory by N. lepida also was concentrated on rosettes that were oriented south, and these had significantly higher nitrogen content than rosettes that …