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91.
Jana S. Stewart Lizhu Wang John Lyons Judy A. Horwatich Roger Bannerman 《Journal of the American Water Resources Association》2001,37(6):1475-1487
ABSTRACT: Multivariate analyses and correlations revealed strong relations between watershed and riparian‐corridor land cover, and reach‐scale habitat versus fish and macroinvertebrate assemblages in 38 warmwater streams in eastern Wisconsin. Watersheds were dominated by agricultural use, and ranged in size from 9 to 71 km2 Watershed land cover was summarized from satellite‐derived data for the area outside a 30‐m buffer. Riparian land cover was interpreted from digital orthophotos within 10‐, 10‐to 20‐, and 20‐to 30‐m buffers. Reach‐scale habitat, fish, and macroinvertebrates were collected in 1998 and biotic indices calculated. Correlations between land cover, habitat, and stream‐quality indicators revealed significant relations at the watershed, riparian‐corridor, and reach scales. At the watershed scale, fish diversity, intolerant fish and EPT species increased, and Hilsenhoff biotic index (HBI) decreased as percent forest increased. At the riparian‐corridor scale, EPT species decreased and HBI increased as riparian vegetation became more fragmented. For the reach, EPT species decreased with embeddedness. Multivariate analyses further indicated that riparian (percent agriculture, grassland, urban and forest, and fragmentation of vegetation), watershed (percent forest) and reach‐scale characteristics (embeddedness) were the most important variables influencing fish (IBI, density, diversity, number, and percent tolerant and insectivorous species) and macroinvertebrate (HBI and EPT) communities. 相似文献
92.
Axel Strauß Katrin Y. Solmsdorff Roger Pech Jens Jacob 《Behavioral ecology and sociobiology》2008,62(10):1551-1558
Predators can strongly influence the microhabitat use and foraging behaviour of prey. In a large-scale replicated field experiment
in East Gippsland, Australia, we tested the effects of reduced alien red fox (Vulpes vulpes) and alien wild dog (Canis lupus familiaris) abundance (treatment) on native bush rat (Rattus fuscipes) behaviour. Bush rats are exposed to two main guilds of predators, namely mammalian carnivores and birds of prey. Tracking
rat movements using the spool-and-line technique revealed that, in treatment sites, rats used ground cover, which provides
shelter from predators, less often than at unmanipulated fox and wild dog abundance (non-treatment sites). In treatment sites,
rats more frequently moved on logs where they would have been exposed to hunting foxes and dogs than in non-treatment sites.
Furthermore, in treatments, rats showed a preference for understorey but not in non-treatments. Hence, bush rats adapted their
behaviour to removal of alien terrestrial predators. Giving-up densities (GUDs) indicated no treatment effects on the marginal
feeding rate of bush rats. Interestingly, GUDs were higher in open patches than in sheltered patches, suggesting higher perceived
predation risk of bush rats during foraging at low versus high cover. The lack of treatment effects on GUDs but the clear
response of bush rats to cover may be explained by the impact of predators other than foxes and wild dogs. 相似文献
93.
Pere Pons Josep M. Bas Roger Prodon Núria Roura-Pascual Miguel Clavero 《Behavioral ecology and sociobiology》2008,62(8):1217-1228
The study of successional gradients may help to understand the relative influence of habitat structure and competition on
territory characteristics. Here, we evaluate the effects of vegetation cover, conspecific and heterospecific densities, and
distance to the nearest neighbor on territory size, shape, and overlap in insectivorous birds. We studied these effects along
a gradient of postfire habitat regeneration in which foliage cover and densities of focal species varied several-fold. We
delineate 197 territories (minimum convex polygons) of the shrub-dwelling Dartford warbler (Sylvia undata) and 255 of the syntopic Sardinian (Sylvia melanocephala), subalpine (Sylvia cantillans) and melodious (Hippolais polyglotta) warblers at three plots in NE Catalonia (Spain and France) in 1987–2005. After accounting for the effect of the number of
locations used to delineate polygons, generalized linear mixed models (GLMM) showed a reduction in territory area of the Dartford
warbler as conspecific density increased and distance to nearest neighbor decreased, in accordance with the contender pressure
hypothesis for territory size regulation. Heterospecific density was not included in the final model of territory size and
the effect of habitat structure was marginal. Territory roundness was positively correlated with its size and with conspecific
density, probably in relation to energetic constraints, and negatively with heterospecific density. Territorial exclusion
was almost complete among Dartford warblers, whereas interspecific territory overlap was extensive and tended to increase
with heterospecific density and with structural diversity along the gradient. Our results support the hypothesis that Mediterranean
warbler coexistence derives from ecological segregation and not from interspecific territoriality. 相似文献
94.
In the first part of the article, the column and the bag experiments concerning removal of polycyclic aromatic hydrocarbons (PAHs) and nonpolar oil (NPO) from tunnel wash waters using organic sorbent materials have been described. This part presents the results of removal of toxic metals. The metals of concern (Al, As, Cd, Cr, Cu, Fe, Pb, Mo, Ni, and Zn) were selected based on the priority toxicant pollutants defined in surface water quality criteria. Concentrations of these metals in the collected effluent... 相似文献
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99.
Assessing the Vulnerability of Coastal Communities to Extreme Storms: The Case of Revere,MA., USA 总被引:6,自引:1,他引:6
Clark George E. Moser Susanne C. Ratick Samuel J. Dow Kirstin Meyer William B. Emani Srinivas Jin Weigen Kasperson Jeanne X. Kasperson Roger E. Schwarz Harry E. 《Mitigation and Adaptation Strategies for Global Change》1998,3(1):59-82
Climate change may affect the frequency, intensity, and geographic distribution of severe coastal storms. Concurrent sea-level
rise would raise the baseline of flooding during such events. Meanwhile, social vulnerability factors such as poverty and
disability hinder the ability to cope with storms and storm damage. While physical changes are likely to remain scientifically
uncertain into the foreseeable future, the ability to mitigate potential impacts from coastal flooding may be fostered by
better understanding the interplay of social and physical factors that produce human vulnerability. This study does so by
integrating the classic causal model of hazards with social, environmental, and spatial dynamics that lead to the differential
ability of people to cope with hazards. It uses Census data, factor analysis, data envelopment analysis, and floodplain maps
to understand the compound social and physical vulnerability of coastal residents in the city of Revere, MA, USA.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
100.
Stephen J. Rossiter Gareth Jones Roger D. Ransome Elizabeth M. Barratt 《Behavioral ecology and sociobiology》2002,51(6):510-518
Female greater horseshoe bats (Rhinolophus ferrumequinum) exhibit strong natal philopatry to their maternity roost over many years, leading to the aggregation of matrilineal kin. Maternity colonies may, therefore, be expected to comprise highly related individuals, and, as such, provide conditions suitable for the evolution of kin-selected behaviours. To test these predictions, we examined relatedness and behaviour among matrilineal kin within a colony in south-west Britain. Genetic analysis of 15 matrilines, identified from microsatellite genotyping and long-term ringing surveys, revealed average relatedness levels of 0.17 to 0.64. In contrast, background relatedness among colony females approximated to zero (0.03). These results suggest that inclusive fitness benefits may only be accrued through discriminate cooperation within matrilines, and not at the wider colony level. To examine whether the potential for such benefits is realised through kin- biased cooperation during foraging, females from two matrilines were radio-tracked simultaneously over 3 years. Pairwise home-range overlap correlated significantly with Hamilton's relatedness coefficient. The greatest spatial associations were observed between females and their adult daughters, which shared both foraging grounds and night roosts, sometimes over several years. Tagged females, however, generally foraged and roosted alone, suggesting that kin-biased spatial association probably does not result from either information-transfer or cooperative territorial defence. Such patterns may instead result from a mechanism of maternal inheritance of preferred foraging and roosting sites. 相似文献