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861.
Transcending scale dependence in identifying habitat with resource selection functions 总被引:1,自引:0,他引:1
DeCesare NJ Hebblewhite M Schmiegelow F Hervieux D McDermid GJ Neufeld L Bradley M Whittington J Smith KG Morgantini LE Wheatley M Musiani M 《Ecological applications》2012,22(4):1068-1083
Multi-scale resource selection modeling is used to identify factors that limit species distributions across scales of space and time. This multi-scale nature of habitat suitability complicates the translation of inferences to single, spatial depictions of habitat required for conservation of species. We estimated resource selection functions (RSFs) across three scales for a threatened ungulate, woodland caribou (Rangifer tarandus caribou), with two objectives: (1) to infer the relative effects of two forms of anthropogenic disturbance (forestry and linear features) on woodland caribou distributions at multiple scales and (2) to estimate scale-integrated resource selection functions (SRSFs) that synthesize results across scales for management-oriented habitat suitability mapping. We found a previously undocumented scale-specific switch in woodland caribou response to two forms of anthropogenic disturbance. Caribou avoided forestry cut-blocks at broad scales according to first- and second-order RSFs and avoided linear features at fine scales according to third-order RSFs, corroborating predictions developed according to predator-mediated effects of each disturbance type. Additionally, a single SRSF validated as well as each of three single-scale RSFs when estimating habitat suitability across three different spatial scales of prediction. We demonstrate that a single SRSF can be applied to predict relative habitat suitability at both local and landscape scales in support of critical habitat identification and species recovery. 相似文献
862.
Alexandra?ZieritzEmail author Gemma?Clucas Lauren?Axtmann David?C.?Aldridge 《Marine Biology》2012,159(4):863-872
When feeding on blue mussels (Mytilus edulis), oystercatchers (Haematopus ostralegus) either stab into the mollusc’s gaping valves or hammer through its dorsal or ventral shell. Whilst the selectivity of hammering
and stabbing oystercatchers for specific prey morphologies has been well studied, the way in which the effects of environment
on M.
edulis morphology can in turn affect feeding methods of H. ostralegus is very poorly understood. Based on morphological analyses on randomly selected shells from three intertidal zones, this
study failed to detect differences in morphology or distribution of dorsally and ventrally hammered shells but confirms the
finding of previous authors that hammering oystercatchers select thinner mussels than stabbing birds. Additionally, we show
that this difference in optimal prey morphology can lead to spatial patterns in oystercatcher feeding behaviour. Whilst at
the low intertidal and higher mid intertidal zones, characterised by comparatively thick shells, most empty shells had apparently
been stabbed, hammering was the dominant feeding behaviour at the lower mid intertidal zone, where shells were thinner. Preference
of hammering birds for smaller mussels was not ubiquitous. Sagittal shell shape was predominantly influenced by allometric
growth effects and had only minor effect on prey selection. All oystercatchers preferred less inflated mussels, with the degree
of shell inflation gradually increasing with higher intertidal elevation. Our results illustrate the importance of small-scale
patterns in prey ecophenotypes in determining the distribution and feeding dynamics of wading birds. 相似文献
863.
Michael?D.?ArendtEmail author Albert?L.?Segars Julia?I.?Byrd Jessica?Boynton J.?David?Whitaker Lindsey?Parker David?W.?Owens Ga?lle?Blanvillain Joseph?M.?Quattro Mark?A.?Roberts 《Marine Biology》2012,159(1):127-139
Thirty-four juvenile loggerhead sea turtles captured by trawling from the Charleston, South Carolina (USA), shipping channel
(32°42′N; −79°47′W) between May 2004 and August 2007 were tagged with satellite transmitters to assess the extent to which
they remained near the capture location given their collection along a seasonal migratory corridor. Seventy-five percent of
juveniles were classified as seasonal residents. Migrants predominantly swam north in the spring and nomads wandered south
in the summer, but predictive indicators for non-resident status were not identified. All but one juvenile generally remained
south of 34°N, within 40 km of shore, and in waters <30 m deep throughout the year. Nine of 14 loggerhead sea turtles monitored
during the winter remained exclusively over the continental shelf, three briefly occurred in oceanic habitats, and two foraged
extensively in oceanic habitats. Residents distributed >15 km from shore between spring and autumn were three times as likely
to occur in oceanic habitats in winter. Modest seasonal movements contrasted with adults tagged at similar latitudes and with
juveniles tagged further north and suggest distinct foraging groups within a regional foraging ground. 相似文献
864.
Michael D. Arendt Albert L. Segars Julia I. Byrd Jessica Boynton J. David Whitaker Lindsey Parker David W. Owens Gaëlle Blanvillain Joseph M. Quattro Mark A. Roberts 《Marine Biology》2012,159(1):101-112
Satellite transmitters were attached to 25 reproductively active and four inactive adult male loggerhead sea turtles (86.6–107.0 cm
SCLmin) captured from the Port Canaveral, FL, USA shipping channel to assess horizontal and vertical distributions. During
the breeding period, male loggerheads aggregated (44% of 755 turtle days) in a 117.6 km2 core area that encompassed the shipping channel. Median dive duration during the breeding period was 27 min (IQR = 15–42
min) and males spent 4% (IQR = 3–5%) of the time at the surface, with significantly shorter dives associated with reproductively
active males. Migrant and resident males dispersed concurrently, with residents shifting > 30 km east across the continental
shelf over a more protracted departure schedule than migrants. Dive duration and time spent at the surface increased through
the fall. Cluster analysis revealed the strongest association for dive duration with sea state during and after the breeding
period, with significantly longer dives during more turbulent conditions. In contrast, univariate associations with surface
interval duration were not elucidated. 相似文献
865.
Synchronous and intermittent reproduction in long-lived plants, known as mast seeding, is induced by climatic cues, but the mechanism explaining variation in masting among neighboring but edaphically segregated species is unknown. Soil nutrients can enhance flowering, and thus, populations on nutrient-rich soils may require less-favorable growing temperatures to flower. We tested this hypothesis by predicting the probability of flowering in response to air temperature for five species of alpine Chionochloa grasses in South Island, New Zealand, over 37 years and relating our predictions to soil N supply (NH4(+) + NO3(-)). Summer air temperatures better predicted flowering than spring air temperatures, which were correlated with soil N mineralization. Species on N-rich soils required lower mean temperatures to induce flowering and/or responded more consistently across a gradient of air temperatures, contributing to the higher probability of their tillers and tussocks flowering at low summer temperatures. Our results suggest that flowering primarily occurs in response to warm summer temperatures, but species on N-rich soils require less favorable growing conditions because they invest relatively less N in seeds. Thus, predicting masting requires a consideration of the interactions among climate, the internal resources of plants, and mineral nutrient uptake. 相似文献
866.
Emeline Pettex Svein-H?kon Lorentsen David Grémillet Olivier Gimenez Robert T. Barrett Jean-Baptiste Pons Céline Le Bohec Francesco Bonadonna 《Marine Biology》2012,159(12):2743-2756
The survival of marine predators depends on behavioural plasticity to cope with changes in prey distribution. Variability in behaviour might predict plasticity and is easier to assess than plasticity. Using miniaturized GPS loggers over several breeding seasons in two Norwegian Northern gannet (Morus bassanus) colonies, we investigated if and how the variability within and between individuals, but also between colonies and years, affected foraging strategies. Results revealed strong individual variability (foraging trip durations, foraging effort and different foraging areas). Individuals from both colonies showed preferred commuting routes, flight bearings and feeding hotspots. Individuals from the largest colony used larger and more foraging areas than individuals from the small colony. Feeding hotspots and foraging ranges varied amongst years in the largest colony only. Our study demonstrated that gannets show flexibility by changing prey fields that are driven by shifting oceanographic conditions. 相似文献
867.
David Natcher Vijayalakshmi Kalagnanam Ramesh Rawal Mark Johnston Abdullah Al Mamun 《国际发展与全球生态学杂志》2018,25(1):47-55
This paper presents the results of research conducted between 2009 and 2014 in the village of Khanda Sharol in the state of Rajasthan, India. Our research objective was to determine how the livelihoods of village residents have been affected by the intensification of forest use, and the resulting loss of domestic access to traditionally used forest resources. Results indicate that changes in forest cover have resulted in a loss of livelihood options for village residents. Yet rather than being victimized by environmental change processes, this paper shows how villagers have responded by partnering with public and private actors to develop a community protected forest area that is now helping villagers to meet their livelihood needs. These findings suggest that sustainable livelihoods in rural regions of India require committed and scaled approaches involving local, public, and private actors. 相似文献
868.
Carmen M. Rosskopf Gianluigi Di Paola David E. Atkinson Germán Rodríguez Ian J. Walker 《Journal of Coastal Conservation》2018,22(5):879-895
A study on the modern dynamics and shoreline changes from 1954 to 2014 of the Molise coast (central Adriatic Sea) has been carried out. Short to long-term shoreline changes and associated surface area variations have been assessed in GIS environment for the study coast, subdivided in nine coastal segments (S1-S9), by using 100-m regularly spaced transects. In addition, the possible influence of natural and anthropogenic factors, especially of climatic variability and engineered shoreline defense structures, has been investigated. The Molise coast has experienced notable long-term erosion (period 1054-2014) that caused an overall coastal land loss of approximately 940,000 m2. Erosion was, yet, limited to coastal segments S1 and S7, nearest to the mouths of major rivers, namely Trigno and Biferno, while the major part of the study coast has remained essentially stable or even advanced. Increased shoreline protection by defense structures has generally favoured shoreline stability and frequently generated shoreline advance, except for segments S1 and S7. Observed differences in shoreline change rates over time at the decadal to interannual scale, have not find a response in the analysis of available data on meteo-marine conditions of the Molise coast and climate variability indices, pointing out the need to improve knowledge on meteomarine conditions and on climatic variability forcing of the study area. From 2004 to 2014, the Molise shoreline remained essentially stable. Nonetheless, most recent shoreline changes (period 2011-2014) and modern shoreline dynamics indicate that erosion has become more widespread, involving at least part of segments S2-S3 and S8-S9, located south of the river mouth segments. The localized long-term shoreline retreat and most recent shoreline erosion appear to be primarily related to channel adjustments of the Biferno and Trigno rivers that occurred since the 1950s under the control of human interventions on the rivers, especially the construction respectively of a dam and a check dam along their lower courses, that trap of most of their solid load, affecting so adversely the sediment budget of the river mouths areas and adjacent beaches. Overall data acquired on the recent shoreline evolution and modern shoreline dynamics of the Molise coast and on related causal factors provide a good basic knowledge for regional coastal management purposes, and for further scientific purposes. Particularly, they suggest the opportunity to deepen a number of aspects such as the relationship between the coast and river catchments feeding it, the possible influences on the Molise shoreline dynamics of the neighbouring coasts, the efficiency/obsolescence of defense structures and the present-day vulnerability to coastal erosion of the Molise coast. 相似文献
869.
Babonneau Frédéric Biscaglia Stéphane Chotard David Haurie Alain Mairet Nicolas Lefillatre Thibaut 《Environmental Modeling and Assessment》2021,26(6):911-926
Environmental Modeling & Assessment - In this paper, we present a comprehensive, multi-timescale approach to evaluate energy transition policies aiming at fully renewable generation in power... 相似文献
870.
Quantitative polymerase chain reaction (qPCR) for the identification and quantification of microbes has become a common tool
for the study of harmful algal blooms (HABs). We developed a qPCR method for the diatom genus Pseudo-nitzschia. Several species of this genus form toxic blooms through the production of the neurotoxin domoic acid (DA). Outbreaks of
toxicity attributed to DA along the US west coast have caused sickness and death of marine mammals and seabirds through food
web contamination. The method developed here quantifies Pseudo-nitzschia spp. at low abundances in natural samples, thereby, providing a method to improve our understanding of the environmental
conditions leading to blooms of these species. This has been accomplished previously by techniques for identification and
quantification that are slow and laborious compared to qPCR. The approach was successfully tested and validated using eight
species of Pseudo-nitzschia and 33 non-target organisms and employed to follow local bloom dynamics. 相似文献