Filters: Tags: aggregation (X)37 results (98ms)
Scaling characteristics of remotely-sensed variables for sparsely-vegetated heterogeneous landscapes
[Spatial structures of demersal fish populations. Characterization, biometric developments and fisheries science. ]
Aggregation of Coleonyx variegatus in diurnal shelter sites is shown to be a statistically valid phenomenon, confirming earlier reports based on subjective impressions. Preliminary data on causative factors suggest that limited burrow availability promotes aggregation. Experiments in which two individuals were placed in cages having an excess of burrows revealed no indication of interindividual attraction. However, these results do not exclude the operation of social factors in aggregation. On the contrary, pilot data provide hints that the sexes may differ in aggregative behavior. We hypothesize that lizard density, sex, and physical variables such as temperature and moisture may be associated with joint burrow...
An approach for aggregating upstream catchment information to support research and management of fluvial systems across large landscapes
Abstract (from http://www.springerplus.com/content/3/1/589): The growing quality and availability of spatial map layers (e.g., climate, geology, and land use) allow stream studies, which historically have occurred over small areas like a single watershed or stream reach, to increasingly explore questions from a landscape perspective. This large-scale perspective for fluvial studies depends on the ability to characterize influences on streams resulting from throughout entire upstream networks or catchments. While acquiring upstream information for a single reach is relatively straight-forward, this process becomes demanding when attempting to obtain summaries for all streams throughout a stream network and across...
Local and landscape-scale data describing patterns of coastal wetland loss in the Texas Chenier Plain, U.S.A., 2017-2018
We characterized coastal wetland responses to flooding stress by measuring vegetation cover, wetland elevation and water elevation in healthy and degrading wetlands dominated by Spartina patens. Wetland elevation was measured using real-time kinematic survey methods. Vegetation cover was determined by visual estimation methods, and water elevation was measured using in situ continuous recorders. In addition to these local-scale responses, we also measured landscape-scale patterns of land and water aggregation or fragmentation using remotely sensed data (Jones et al., 2018). Associated products: Jones, W.R., Hartley, S.B., Stagg, C.L., and Osland, M.J. 2018. Land-water classification for selected sites in McFaddin...
Influenza A virus reassortants with surface glycoprotein genes of the avian parent viruses: Effects of HA and NA gene combinations on-virus aggregation
Desensitization of pigment granule aggregation in Xenopus laevis melanophores: melatonin degradation rather than receptor down-regulation is responsible
Density dependent model describing Salmo trutta population dynamics in an arborescent river network. Effects of dams and channelling