scholarly journals Habitat selection by the European hare in arable landscapes: The importance of small-scale habitat structure for conservation

2018 ◽  
Vol 8 (23) ◽  
pp. 11619-11633 ◽  
Author(s):  
Martin Mayer ◽  
Wiebke Ullmann ◽  
Peter Sunde ◽  
Christina Fischer ◽  
Niels Blaum
Keyword(s):  
Habitat Selection ◽  
Habitat Structure ◽  
Small Scale ◽  
European Hare

Habitat structure and association with ungulates drive habitat selection and grouping behaviour of lesser rhea ( Rhea pennata subsp. pennata )

2020 ◽  
Vol 46 (1) ◽  
pp. 86-97
Author(s):  
Esperanza C. Iranzo ◽  
Juan Traba ◽  
Cristina Mata ◽  
Pablo Acebes ◽  
Juan E. Malo
Keyword(s):  
Habitat Selection ◽  
Habitat Structure ◽  
Lesser Rhea

scholarly journals Effect of Tidal Stage on Sediment Concentrations and Turbulence by Vessel Wake in a Coastal Plain Saltmarsh

2019 ◽  
Vol 7 (6) ◽  
pp. 192
Author(s):  
Richard Styles ◽  
Michael A. Hartman
Keyword(s):  
Coastal Plain ◽  
Habitat Structure ◽  
Sediment Concentration ◽  
Small Scale ◽  
Characteristic Time Scale ◽  
Suspended Material ◽  
Turbulent Fluctuations ◽  
High Concentrations ◽  
Tidal Stage ◽  
Water Elevation

Vessel generated waves can impact shoreline stability and habitat structure in many waterways. Sheltered regions, such as coastal plain saltmarshes, support fragile ecosystems and can be particularly vulnerable to the effects of unregulated vessel operations. Instruments for measuring currents and sediment concentration were deployed in a coastal plain saltmarsh to examine the small-scale physical characteristics of the vessel wake generated by recreational craft typical of this environment. The response to vessel wake varied sharply depending upon the stage of the tide. At low tide, waves breaking on the exposed bank produced high concentrations of suspended material that were transported offshore through turbulent diffusion. When the water elevation exceeded the toe of the marsh scarp, the concentration and turbulent kinetic energy exhibited less of a statistically significant variation in response to vessel passage. For the most energetic flows, the vessel orbital velocities were dwarfed by turbulent fluctuations generated by the sheared tidal boundary layer. While further research is required, preliminary findings indicate that the dissipation of vessel wake energy may stimulate or enhance shear generated turbulence if the characteristic wave period is similar to the characteristic time scale of the energy containing eddies.

scholarly journals Small-Scale Habitat Structure Modulates the Effects of No-Take Marine Reserves for Coral Reef Macroinvertebrates

PLoS ONE ◽  
2013 ◽  
Vol 8 (3) ◽  
pp. e58998 ◽  
Author(s):  
Pascal Dumas ◽  
Haizea Jimenez ◽  
Christophe Peignon ◽  
Laurent Wantiez ◽  
Mehdi Adjeroud
Keyword(s):  
Coral Reef ◽  
Habitat Structure ◽  
Marine Reserves ◽  
Small Scale

Small mammals and habitat structure in lowland rain forest of Peninsular Malaysia

1985 ◽  
Vol 1 (1) ◽  
pp. 5-22 ◽  
Author(s):  
Catherine Kemper ◽  
David T. Bell
Keyword(s):  
Small Mammal ◽  
Rain Forest ◽  
Habitat Structure ◽  
Primary Forest ◽  
Small Scale ◽  
Simple Method ◽  
Habitat Differences ◽  
Faunal Distribution ◽  
Habitat Variables ◽  
Trapping Sites

ABSTRACTA method of assessing rain forest structure by ranking relative abundance of 41 habitat variables was used to describe habitat differences among six trapping sites (324 subsites). Variables included aspects of all vegetation layers but concentrated on those considered to be important to small mammal distribution. Ordination and classification methods resulted in similar analyses of the data. Differences in habitat structure were primarily related to the moisture conditions of the trapping sites and secondarily to their successional age (regenerating versus primary forest). The most important habitat variables for differentiating between sites were LITTER, CLEARING, SOILS, PIG DAMAGE, FLOODING, FAN PALM, EMERGENTS, CANOPY SURFACE and SEEDLINGS. Habitat structure also varied within sites with some suggestion of small-scale patterning.Small mammal captures were more likely in drier sites and subsites, but there was no difference in trap success between regenerating sites and primary forest sites. Greater numbers of species were captured in sites containing a variety of habitats, a discrete layering of vegetation and an extensive understorey. Small mammal captures were positively associated with five habitat variables (EMERGENTS, LITTER, ROTTING LOGS, SEEDLINGS, ROUGH BARK) and negatively associated with five others (LAYERS, BERTAM, SEDGES, PIG DAMAGE, FLOODING). The destruction caused by pigs is thought to be a major factor since it reduces litter and food availability over wide areas. Leopoldamys sabanus was the most abundant small mammal captured (40/68 individuals) and trap success differences among sites (0.4–1.9%) reflect its preference for higher, well-drained habitats.The study demonstrates the usefulness of a simple method of ranking habitat features according to importance/abundance thus eliminating the all but impossible task of direct measurements in this complex system. This simple method of habitat description provides a basis for studying variables influencing faunal distribution patterns.

Do animals select habitat at small or large scales? An experiment with meadow voles (Microtus pennsylvanicus)

2007 ◽  
Vol 85 (4) ◽  
pp. 479-487 ◽  
Author(s):  
M.L. Oatway ◽  
D.W. Morris
Keyword(s):  
Habitat Selection ◽  
Spatial Scales ◽  
Habitat Choice ◽  
Microtus Pennsylvanicus ◽  
Small Scale ◽  
Ecological Communities ◽  
Old Field ◽  
Meadow Voles ◽  
Density Dependent ◽  
Density Dependent Habitat Selection

Habitat and patch use are crucial to the dynamics of populations and the structure of ecological communities. But ecologists have not rigorously tested whether animals choose habitat at small or large scales. If individuals base their patch and habitat choices on fine-scale differences in habitat, then their use of different sites should correspond with measures of microhabitat at those sites. But if individuals use density to assess and respond to habitat at larger spatial scales, then site use should correspond with the scale of density-dependent habitat selection. We tested these predictions with experiments that measured microhabitat and monitored the use of capture sites by meadow voles ( Microtus pennsylvanicus Ord, 1815) in 0.25 ha old-field enclosures. We varied the density of voles in pairs of adjacent enclosures and tested for density-dependent habitat selection. Then we assessed whether their frequency of captures at trapping stations was best predicted at the small scale of microhabitat or at the much larger scale of enclosures where density varied. The voles selected habitat at different scales. When the use of enclosures was predicted by density, the scale of density-dependent choice trumped the use of small-scale patches. And when voles selected amongst different small-scale patches, their use of enclosures was independent of density. These results suggest that assessments of spatial scale in habitat use must include tests for both scale- and density-dependent habitat choice.

scholarly journals A sea of tentacles: optically discernible traits resolved from planktonic organisms in situ

2019 ◽  
Vol 76 (7) ◽  
pp. 1959-1972 ◽  
Author(s):  
Mark D Ohman
Keyword(s):  
Habitat Structure ◽  
Biogeochemical Cycles ◽  
Plankton Community ◽  
Small Scale ◽  
Fluid Medium ◽  
Naturally Occurring ◽  
Fluid Environment ◽  
Freely Suspended ◽  
Plankton Community Structure

Abstract Trait-based simplifications of plankton community structure require accurate assessment of trait values as expressed in situ. Yet planktonic organisms live suspended in a fluid medium and often bear elongate appendages, delicate feeding structures, and mucous houses that are badly damaged upon capture or removal from the fluid environment. Fixatives further distort organisms. In situ imaging of zooplankton from a fully autonomous Zooglider reveals a suite of trait characteristics that often differ markedly from those inferred from conventionally sampled plankton. In situ images show fragile feeding appendages in natural hunting postures, including reticulate networks of rhizopods, feeding tentacles of cnidarians, and tentilla of ctenophores; defensive spines and setae of copepods; intact mucous houses of appendicularians; and other structures that are not discernible in conventionally collected zooplankton. Postures characteristic of dormant copepods can be identified and the presence of egg sacs detected. Intact, elongate diatom chains that are much longer than measured in sampled specimens are resolvable in situ. The ability to image marine snow, as well as small-scale fluid deformations, reveals micro-habitat structure that may alter organismal behaviour. Trait-based representations of planktonic organisms in biogeochemical cycles need to consider naturally occurring traits expressed by freely suspended planktonic organisms in situ.

Spatial distribution models in a frugivorous carnivore, the stone marten (Martes foina): is the fleshy-fruit availability a useful predictor?

2010 ◽  
Vol 60 (4) ◽  
pp. 423-436 ◽  
Author(s):  
Sara Cabezas-Díaz ◽  
Emilio Virgós ◽  
Jorge Lozano ◽  
Julián Mangas
Keyword(s):  
Habitat Structure ◽  
Spatial Scales ◽  
Tree Cover ◽  
Scale Model ◽  
Fleshy Fruit ◽  
Small Scale ◽  
Stone Marten ◽  
Martes Foina ◽  
Habitat Models ◽  
Fruit Availability

AbstractFleshy-fruit availability is rarely used as a predictor in stone marten (Martes foina) habitat models, despite its frugivorous carnivore diet. Data on stone marten occurrence, habitat structure and fleshy-fruit species abundance was collected along 2 km long survey routes within 2 × 2 km sample plots (n = 30). Two different spatial scales were considered: 1) the entire survey route; and 2) 200 m segments within each 2 km survey route. Data analyses included Poisson General Linear Models (GLM) and Generalized Linear Mixed Models (GLMM) for the first and second approaches, respectively.Strawberry tree (Arbutus unedo) availability was significantly and positively correlated to stone marten occurrence at both spatial scales, particularly for the large-scale model. At the larger scale, a lower correlation to the traditional habitat structure variables was observed. Tree cover was the most important variable in the small-scale model, but strawberry tree availability was also an important predictor. Stone marten abundance was low in areas of high tree cover and absence of strawberry trees; emphasising the prominent role of strawberry trees per se in the abundance of stone martens. Our results indicated that including fine, field-derived estimates of key food resources for species can increase the utility of habitat models.

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