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1.
Corridors are predicted to benefit populations in patchy habitats bypromoting movement, which should increase population densities, gene flow, andrecolonization of extinct patch populations. However, few investigators haveconsidered use of the total landscape, particularly the possibility ofinterpatch movement through matrix habitat, by small mammals. This studycompares home range sizes of 3 species of small mammals, the cotton mouse(Peromyscus gossypinus), old-field mouse (P.polionotus) and cotton rat (Sigmodon hispidus)between patches with and without corridors. The study site was in S. Carolina,USA. Corridor presence did not have astatistically significant influence on average home range size. Habitatspecialization and sex influenced the probability of an individual movingbetween 2 patches without corridors. The results of this study suggest thatsmall mammals may be more capable of interpatch movement without corridors thanis frequently assumed.This revised version was published online in May 2005 with corrections to the Cover Date. 相似文献
2.
A large-scale experimental landscape study was conducted to examine the use of corridors and the forest matrix habitat by the hispid cotton rat (Sigmodon hispidus). The role of micro- habitat selection by S. hispidus in influencing routes of movement was also investigated. The experimental landscape consisted of ten 1.64-ha patches (each 128×128 m) established in a loblolly (Pinus teada) forest. Four of the patches were isolated while the other six were connected in pairs by a 32-m wide corridor. Cotton rats (N=96) were simultaneously released into both an isolated and connected patch, and monitored by radiotelemetry for 10 days. We found that the forest matrix was not a barrier to movements of cotton rats. Fifty percent of the cotton rats moved through the matrix. Corridors had no significant effect on the number of animals leaving connected patches (60%) compared to isolated patches (50%). However, corridors were the preferred route to leave a connected patch. Colonization success for cotton rats leaving connected and isolated patches did not significantly differ. Cotton rats exhibited micro-habitat preferences and these preferences differed within patch/corridor and matrix habitats. In patch/corridor habitats, cotton rats selected sites with tall (>1 m) shrubs and high percent cover. In the forest matrix, cotton rats selected sites with abundant cover by vines and low tree canopy cover. Movement patterns of Sigmodon hispidus are not strongly influenced by large-scale landscape spatial structures. Micro-habitat selection, however, does influence movement patterns. These findings have important implications regarding habitat connectivity for small mammals. 相似文献
3.
While several studies have demonstrated that roads can act as barriers to small mammal movement, the relationship between
road density and small mammal abundance has not yet been investigated. In southeastern Ontario, Peromyscus leucopus (white-footed mice) suffer high over-winter mortality rates, resulting in small springtime populations and frequent local
extinctions. Peromyscus leucopus movement is known to be inhibited by roads, which should result in lower rates of immigration into and recolonization of
habitats in landscapes with high road density. We tested two predictions: (1) Forest sites situated in landscapes with high
road densities have a higher chance of P. leucopus being absent during the early spring than forest sites situated in landscapes with low road densities and (2) P. leucopus populations during the summer are smaller in forest sites situated in landscapes with high road densities than in landscapes
with low road densities. We sampled P. leucopus in focal patches within nineteen landscapes (7 rural, low-road-density landscapes; 7 rural, high-road-density landscapes;
5 urban landscapes). There was no significant relationship between road density and the presence/absence of P. leucopus during the early spring. We found a significant positive effect of road density on P. leucopus relative abundance during the summer, even when we excluded the urban landscapes and based the analysis on only the 14 rural
landscapes. Our results suggest that any negative effect of roads on P. leucopus populations, created by their inhibition to moving across roads, is far outweighed by some positive effect of roads on P. leucopus abundance. We suggest that the two most likely explanations are that roads are positively correlated with an important as-yet-undetermined
component of habitat quality, or that roads positively affect P. leucopus by negatively affecting their predators. 相似文献
4.
We tested the effects of increased landscape corridor width and corridor presence on the population dynamics and home range use of the meadow vole (Microtus pennsylvanicus) within a small-scale fragmented landscape. Our objective was to observe how populations behaved in patchy landscapes where the animals home range exceeded or equaled patch size. We used a small-scale replicated experiment consisting of three sets of two patches each, unconnected or interconnected by 1-m or 5-m wide-corridors, established in an old-field community (S.W. Ohio). Control (0-m) treatments supported significantly lower vole densities than either corridor treatment. Females were the dominant resident sex establishing smaller home ranges (<150m2) than males (>450m2). Significantly more male voles dispersed between patches with corridors than between patches without corridors. However, no difference was observed regarding the number of male voles dispersing between patches connected by corridors when compared to the number dispersing across treatments. Dispersal between connected patches was restricted to corridors based on tracking tube data. Corridor presence was more important than corridor width regarding the movement of male voles within their home range. 相似文献
5.
Small mammals in heterogeneous environments have been found to disperse along corridors connecting habitat patches. Corridors may have different survivability values depending on their size and the degree of cover they provide. This deterministic model tests the effects of varying corridor quality on the demographics of a metapopulation of Peromyscus leucopus. Two types of corridors are defined based on the probability of survival during a dispersal event. Results indicate that mortality during movement through corridors influences metapopulation demographics. We found that:
- Any connection between two isolated patches is better than no connection at all in terms of persistence and population size at equilibrium.
- Metapopulations with exclusively high quality corridors between patches have a larger population size at equilibrium than do those with one or more low quality corridors.
- Increasing the number of high quality corridors between patches has a positive effect on the size of the metapopulation while increasing the number of low quality corridors has a negative effect.
- The addition to a metapopulation of a patch connected by low quality corridors has a negative effect on the metapopulation size. This suggest the need for caution in planning corridors in a managed landscape.
- There is no relationship between the number of corridors and the metapopulation size at equilibrium when the number of connected patches is held constant.
- Geometrically isolated patches connected by low quality corridors are most vulnerable to local extinctions.
6.
Cultural landscapes of Germany are patch-corridor-matrix mosaics for an invasive megaforb 总被引：1，自引：0，他引：1
Predicting the vulnerability of landscapes to both the initial colonisation and the subsequent spread of invasive species
remains a major challenge. The aim of this study was to assess the relative importance of sub-patch level factors and landscape
factors for the invasion of the megaforb Heracleum mantegazzianum. In particular, we tested which factors affect the presence in suitable habitat patches and the cover-percentage within invaded
patches. For this purpose, we used standard (logistic) regression modelling techniques. The regression analyses were based
on inventories of suitable habitat patches in 20 study areas (each 1 km2) in cultural landscapes of Germany. The cover percentage in invaded patches was independent from landscape factors, except
for patch shape, and even unsatisfactorily explained by sub-patch level factors included in the analysis (R
2 = 0.19). In contrast, presence of H. mantegazzianum was affected by both local and landscape factors. Woody habitat structure decreased the occurrence probability, whereas vicinity
to transport corridors (rivers, roads), high habitat connectivity, patch size and perimeter-area ratio of habitat patches
had positive effects. The significance of corridors and habitat connectivity shows that dispersal of H. mantegazzianum through the landscape matrix is limited. We conclude that cultural landscapes of Germany function as patch-corridor-matrix
mosaics for the spread of H. mantegazzianum. Our results highlight the importance of landscape structure and habitat configuration for invasive spread. Furthermore,
this study shows that both local and landscape factors should be incorporated into spatially explicit models to predict spatiotemporal
dynamics and equilibrium stages of plant invasions. 相似文献
7.
Connectivity, or the integration of populations into a single demographic unit, is an often desired, but largely untested
aspect of wildlife corridors. Using a corridor system that was established at least 85 years prior, we investigated the extent
of connectivity provided. This was undertaken using a combined ecological and genetic approach with connectivity estimated
by gene flow. Vegetation within the corridor was found to be comparable in physical structure and species composition to that
within the connected patches and the two target species (Melomys cervinipes and Uromys caudimaculatus) were shown to occur along the corridor but not within the surrounding matrix. These factors indicated that the corridor
was suitable for use as a model system. The population structure (weights of individuals, sex ratios and the percentage of
juveniles) of both species were also similar within the corridor and the connected patches suggesting that the corridor provided
the resources necessary to sustain breeding populations along its length. Despite this, populations in patches linked by the
corridor were found to show the same significant levels of genetic differentiation as those in isolated habitats. M. cervinipes, but not U. caudimaculatus, also showed population differentiation within the continuous habitat. Although based on only one corridor system, these
results clearly demonstrate that connectivity between connected populations will not always be achieved by the construction
or retention of a corridor and that connectivity cannot be inferred solely from the presence of individuals, or breeding populations,
within the corridor.
C. Wilson: deceased 相似文献
8.
Individual movement is a key process affecting the distribution of animals in heterogeneous landscapes. For specialist species in patchy habitat, a central issue is how dispersal distances are related to landscape structure. We compared dispersal distances for cactus bugs (Chelinidea vittiger) on two naturally fragmented landscapes (≤ 4% suitable habitat) with different matrix structures (i.e., vegetation height of nonsuitable habitat between suitable patches). Using mark-release-recapture studies, we determined that most transfers between cactus patches occurred during the mating season. Dispersal distances were reduced by > 50% on the landscape that had reduced structural connectivity due to relatively high matrix structure and low patch density. An experiment with detailed movement pathways demonstrated that greater matrix structure decreased mean step lengths, reduced directionality, and thus decreased net displacement by > 60%. However, habitat edges between two matrix elements that differed substantially in resistance to movement were completely permeable. Therefore, the difference in distributions of dispersal distances between the two landscapes mainly reflected the average resistance of matrix habitat and not the level of matrix heterogeneity per se. Our study highlights the merits of combining estimates of dispersal distances with insights on mechanisms from detailed movement pathways, and emphasizes the difficulty of treating dispersal distances of species as fixed traits independent of landscape structure. 相似文献
9.
Modeling patch occupancy: Relative performance of ecologically scaled landscape indices 总被引：1，自引：1，他引：0
In fragmented landscapes, the likelihood that a species occupies a particular habitat patch is thought to be a function of
both patch area and patch isolation. Ecologically scaled landscape indices (ESLIs) combine a species’ ecological profile,
i.e., area requirements and dispersal ability, with indices of patch area and connectivity. Since their introduction, ESLIs
for area have been modified to incorporate patch quality. ESLIs for connectivity have been modified to incorporate niche breadth,
which may influence a species’ ease in crossing the non-habitat matrix between patches. We evaluated the ability of 4 ESLIs,
the original and modified indices of area and connectivity, to explain patterns in patch occupancy of 5 forest rodents. Occupancy
of eastern gray squirrels (Sciurus carolinensis), North American red squirrels (Tamiasciurus hudsconicus), fox squirrels (Sciurus niger), white-footed mice (Peromyscus leucopus), and eastern chipmunks (Tamias striatus) was modeled at 471 sites in 35 landscapes sampled from the upper Wabash River basin in Indiana. Models containing ESLIs
received support for gray squirrels, red squirrels, and chipmunks. Modified ESLIs were important in models for red squirrels.
However, none of the models demonstrated high predictive ability. Incorporating habitat quality and using surrogate measures
of dispersal can have important effects on model results. Additionally, different responses of species to area, isolation,
and habitat quality suggest that generalizing patterns of metapopulation dynamics was not justified, even across closely related
species. 相似文献
10.
The interaction between landscape structure and spatial patterns of plant invasion has been little addressed by ecologists
despite the new insights it can provide. Because of their spatial configuration as highly connected networks, linear wetlands
such as roadside or agricultural ditches, can serve as corridors facilitating invasion at the landscape scale, but species
dynamics in these important habitats are not well known. We conducted a landscape scale analysis of Phragmites australis invasion patterns (1985–2002 and 1987–2002) in two periurban areas of southern Québec (Canada) focusing on the interaction
between the network of linear wetlands and the adjacent land-uses. Results show that, at the beginning of the reference period,
the two landscapes were relatively non-invaded and populations occurred mostly in roadside habitats which then served as invasion
foci into other parts of the landscape. The intrinsic rates of increase of P. australis populations in linear anthropogenic habitats were generally higher than those reported for natural wetlands. Riparian habitats
along streams and rivers were little invaded compared to anthropogenic linear wetlands, except when they intersected transportation
rights-of-way. Bivariate spatial point pattern analysis of colonization events using both Euclidian and network distances
generally showed spatial dependence (association) to source populations. An autologistic regression model that included landscape
and edaphic variables selected transportation rights-of-way as the best predictor of P. australis occurrence patterns in one of the landscapes. Given the high invasion rates observed, managers of linear wetlands should
carefully monitor expansion patterns especially when roads intersect landscapes of conservation or economic value. 相似文献
11.
Measuring edge effects in complex landscapes is often confounded by the presence of different kinds of natural and anthropogenic
edges, each of which may act differently on organisms inhabiting habitat patches. In such landscapes, proportions of different
habitats surrounding nests within patches often vary and may affect nesting success independently of distance to edges. We
developed methods to measure and study the effects of multiple edges and varying habitat composition around nests on the breeding
success of the Acadian flycatcher (Empidonax virescens), an understory, open-cup nesting songbird. The Kaskaskia River in Southwestern Illinois was our study area and consists
of wide (>1000-m) floodplain corridors embedded in an agricultural matrix with a variety of natural (wide rivers, backwater
swamps, and oxbow lakes) and anthropogenic (internal openings, and agricultural) habitats. We also measured vegetation structure
around each nest. Nest survival increased with increasing nest concealment, and probabilities of brood parasitism increased
with increasing distances from anthropogenic and natural water-related openings surrounding nests. The magnitude of these
effects was small, probably because the landscape is saturated with nest predators and brood parasites. These results illustrate
the importance of considering both larger landscape context and details of natural and anthropogenic disturbances when studying
the effects of habitat fragmentation on wildlife. 相似文献
12.
This study describes the demographic features of a population of Sigmodon hispidus utilizing the habitat mosaic provided by a Carolina Bay on the Atlantic coastal plain of South Carolina. A total of 71 cotton rats were captured 160 times on a 4 ha grid during a winter decline from 25/ha to less that 1/ha. Body weights of adults declined until early February and then increased; those of subadults grew very slowly until February followed by a spurt in growth. Weight gain did not differ between survivors and non-survivors for males, but female survivors gained 1.5 g per week more than non-survivors. Female subadults exhibited higher mortality early in the decline and males later.Adult females were randomly distributed across 8 microhabitats, whereas adult males were almost exclusively confined to heavy Rubus cover. Subadult males used wet sites more than any other cohort; subadult females were widely distributed using drier sites most frequently. By the end of the decline, all survivors were localized in Rubus-dominated patches. No statistically significant changes in electromorph genotypes or allele frequencies were detected, but survivors had a higher frequency of the F-allele at the adenylate kinase locus than did non-survivors (42.3% vs. 16.7%).Our findings affirm the importance of a landscape perspective in understanding the population dynamics of cotton rats, and show how a habitat mosaic influences survival differentially among sex-age cohorts. 相似文献
13.
This study investigated the efficacy of linear landscape elements in fragmented landscapes as corridors for perennial grassland
species with short-range seed dispersal. Corridors are assumed to be essential for the persistence of metapopulations in fragmented
landscapes, but it is unclear to what extent linear landscape elements such as ditch banks and road verges can function as
corridors for those species. The principal factors that determine the rate of migration through corridors include the width
and habitat quality of patches within a corridor (expressed as the population growth rate λ) and the dispersal capacity of
plants (expressed as the slope α of the relationship between seed number and log-distance).
A cellular automation model was used to simulate the effects of the principal factors on the rate of migration. Simulations
with different levels of the principal factors showed highly significant and positive main effects of dispersal capacity,
habitat quality and width of corridors on the migration rate. Significant interactions existed between dispersal capacity
× width and dispersal capacity × habitat quality (p<0.0001), indicating that the effects of width and habitat quality depended
on the dispersal capacity. In narrow corridors most of the dispersed seeds were deposited outside the corridor, which significantly
reduced migration rates, especially for species with long-range dispersal (α=−0.4). In wide corridors (up to 20 m), seed losses
were much smaller and migration rates approximated those of continuous habitats. The contribution of the few long-range seeds
to the rate of migration was significant when habitat quality was high (population growth rates up to 2.5). However, in all
simulations migration rates were very low,i.e.<5 m/yr.
It is concluded that linear landscape elements are not effective corridors in fragmented landscapes for plants with short-range
seed dispersal, because migration rates are low (<5 m/yr), landscape elements vary in the percentage of high quality patches,
and refugia and suitable habitat patches are frequently several kilometres apart, making a cohesive infrastructure of corridors
for plants elusive. It is argued that the best way to conserve endangered plant species that encounter dispersal barriers
is to harvest seeds from nearby source populations and introduce them as suitable habitats. 相似文献
14.
Use of space by the yellow-footed antechinus, Antechinus flavipes, in a fragmented landscape in South Australia 总被引：2，自引：1，他引：1
An understanding of how individual species are able to persist and move within fragmented landscapes is critical for elucidating
the effects of fragmentation and aiding in the management of species. Here, we studied movement behaviour of the dasyurid
Antechinus flavipes in a heavily fragmented landscape using trapping and radiotracking. We assessed the ability of animals to move within and
amongst small (<6 ha) remnants and make use of the matrix, and investigated how females used the available space within remnants.
Seventeen between-remnant movements were detected from 428 recaptures, ranging in length from 30 to 720 m and averaging 352
m. Most were by adult males during the breeding season, with 40% more than 500 m. Landscape types traversed would have included
exotic pine plantations, open grazed areas and roads. Between-site movements of juveniles were only detected on three occasions.
However, few young males were captured as adults, suggesting high dispersal rates and considerable matrix use. Conversely,
despite high female recapture rates, again only three between-site movements were recorded. Radiotracking further indicated
that females confined foraging to remnants, with occasional forays to isolated trees in paddocks. Female home range areas
were similar for remnants and forest (0.04–0.66 ha). A. flavipes is clearly able to persist in very small patches of native vegetation in the landscape studied here. Its long-term persistence
appears dependent on the ability of females to maintain a presence in the small remnants, and of unrelated males to move between
remnants to breed with resident females. This study illustrates the importance of recognising the occurrence of metapopulations
in fragmented landscapes for conservation management. 相似文献
15.
John L. Orrock Gregory R. Curler Brent J. Danielson David R. Coyle 《Landscape Ecology》2011,26(10):1361-1372
The size, shape, and isolation of habitat patches can affect organism behavior and population dynamics, but little is known
about the relative role of shape and connectivity in affecting ecological communities at large spatial scales. Using six sampling
sessions from July 2001 until August 2002, we collected 33,685 arthropods throughout seven 12-ha experimental landscapes consisting
of clear-cut patches surrounded by a matrix of mature pine forest. Patches were explicitly designed to manipulate connectivity
(via habitat corridors) independently of area and edge effects. We found that patch shape, rather than connectivity, affected
ground-dwelling arthropod richness and beta diversity (i.e. turnover of genera among patches). Arthropod communities contained
fewer genera and exhibited less turnover in high-edge connected and high-edge unconnected patches relative to low-edge unconnected
patches of similar area. Connectivity, rather than patch shape, affected the evenness of ground-dwelling arthropod communities;
regardless of patch shape, high-edge connected patches had lower evenness than low- or high-edge unconnected patches. Among
the most abundant arthropod orders, increased richness in low-edge unconnected patches was largely due to increased richness
of Coleoptera, whereas Hymenoptera played an important role in the lower evenness in connected patches and patterns of turnover.
These findings suggest that anthropogenic habitat alteration can have distinct effects on ground-dwelling arthropod communities
that arise due to changes in shape and connectivity. Moreover, this work suggests that corridors, which are common conservation
tools that change both patch shape and connectivity, can have multiple effects on arthropod communities via different mechanisms,
and each effect may alter components of community structure. 相似文献
16.
Structural features of both habitat remnants and surrounding matrix can be important for explaining plant population dynamics
and ecosystem functions in human-impacted landscapes. However, little is known about how the structural features of the adjacent
matrix affect biotic interactions and whether such context effects are subject to temporal variations. Using the hawthorn
Crataegus monogyna in northern Spain, we studied matrix effects on two sequential plant-animal interactions, frugivory by birds and postdispersal
seed predation by rodents. Using Hierarchical Linear Models, we compared the magnitude of both interactions on trees located
in two patch types that strongly differed in structural features of the adjacent matrix habitat: patches totally surrounded
by a degraded, structurally contrasted pastures (unconnected patches), and trees growing in patches adjacent to a lowly degraded,
structurally similar mature forests (connected patches). We compared outcomes for 2005 and 2006, which were years with strong
differences in community-wide fruit and seed abundance. Frugivory rate did not differ between patch types in either year,
likely related to high mobility of birds. Seed predation rates were higher in unconnected patches than in connected ones,
but only in 2005. We conclude that strong interannual fluctuations in resource availability are not rare in temperate systems
and that recruitment rates could be frequently reduced within unconnected patches, thus collapsing plant regeneration processes
of hawthorn populations. Overall, our results suggest that generalizations about potential effects of the matrix on plant-animal
interactions within remnant patches must consider: (1) species-specific habitat responses of the organisms, (2) suitability
of neighbouring habitats in terms of food supply, and (3) temporal variations in plant-resource availability for interacting
animals. 相似文献
17.
The understanding and prediction of the responses of animal populations to habitat fragmentation is a central issue in applied
ecology. The identification of habitat variables associated to patch occupancy is particularly important when habitat quality
is affected by human activities. Here, we analyze the influence of patch and landscape characteristics on patch occupancy
by the subterranean herbivorous rodent Ctenomys porteousi. Patch occupancy was monitored in a network of 63 habitat patches identified by satellite imagery analysis which extends
along almost the whole distributional range for C. porteousi. Suitable habitat for the occurrence of C. porteousi is highly fragmented and represents <10% of the total area in its distributional range. The distribution of C. porteousi in the patch network is affected not only by characteristics of the habitat patches, but also by those of the surrounding
landscape matrix. Significant differences between occupied and empty patches were found in several environmental variables.
Overall, occupied patches were larger, less vegetated, more connected, and had larger neighbor patches than empty patches.
A stepwise procedure on a generalized linear model selected four habitat variables that explain patch occupancy in C. porteousi; it included the effects of habitat quality in the matrix surrounding the patch, average vegetation cover in the patch, minimum
vegetation cover in the matrix surrounding the patch, and the area of the nearest neighbor patch. These results indicate that
patch occupancy in C. porteousi is strongly influenced by the availability and quality of habitat both in the patch and in the surrounding landscape matrix. 相似文献
18.
Metapopulation and optimal foraging theories predict the presence of animals and their duration, respectively, in foraging
patches. This paper examines use of these two theories to describe the movements and patterns of foraging in patches used
by Caspian gulls (Larus
cachinnans) at inland reservoirs during the chick-rearing period. We assumed that birds would move differently across diverse habitats,
with some types of land cover less permeable than others, and some landscape features acting as corridors. We also expected
larger and less isolated patches, and patches that were close to corridors, to have a higher probability of the presence of
foraging birds, and that they would be more abundant, forage for a shorter time, and hunt smaller prey than in small, more
isolated patches surrounded by barriers. Forests seem to be a much less permeable type of land cover, whereas rivers became
corridors for Caspian gulls during foraging trips. Probability of bird presence was positively related to the size of foraging
patches and negatively linked with distance to the nearest river, distance to the nearest foraging patch, and the presence
of forests in the vicinity. The same factors significantly affected bird abundance. Contrary to expectations, the duration
and success of foraging were not influenced by any variable we measured, suggesting that although larger patches contain a
higher abundance of fish, their density and the probability of capturing prey were relatively stable among the various patches.
However, gulls that foraged in more isolated ponds that were located further from the river and the colony, and also surrounded
by forest, captured larger fish more often than birds that foraged near the colony in less-isolated patches. Pooling metapopulation
and optimal foraging concepts seems to be valuable in describing patch use by foraging animals.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
19.
The distribution of the northern brown bandicoot (Isoodon macrourus), a medium-sized ground-dwelling marsupial, was examined in habitat fragments within the urban landscape of the city of Brisbane,
Australia. From surveys conducted in 68 fragments, bandicoots were found to be present in 33 (49%) despite widespread habitat
loss and fragmentation. Logistic regression analysis revealed that of 13 measured independent variables, functional connectivity
was the only factor that significantly predicted the presence of bandicoots within fragments, with connectivity positively
correlated with the likelihood of occupation. Functional connectivity was equated to the likelihood of bandicoot immigration
into the focal fragment from the nearest occupied fragment, based on the estimated resistance to movement offered by the intervening
matrix. Within Brisbane, riparian habitat fragments typically have a relatively high level of functional connectivity, as
thin strips of vegetation fringing waterways serve as corridors between larger riparian areas and facilitate the movement
of bandicoots between patches. Analyses based on the Akaike Information Criterion revealed that the optimal model based on
landscape context variables was convincingly better supported by the data than the optimal model produced from fragment characteristics.
However, it is important to examine both internal attributes of habitat fragments and external features of the surrounding
landscape when modelling the distribution of ground-dwelling fauna in urban environments, or other landscapes with a highly
variable matrix. As urban centres throughout the world expand, it is crucial that the ecology of local wildlife be considered
to ensure functional connection is maintained between habitat patches, especially for the conservation of species that are
highly susceptible to fragmentation. 相似文献
20.
Studies on the distribution of mammalian carnivores in fragmented landscapes have focused mainly on structural aspects such
as patch and landscape features; similarly, habitat connectivity is usually associated with landscape structure. The influence
of food resources on carnivore patch use and the important effect on habitat connectivity have been overlooked. The aim of
this study is to evaluate the relative importance of food resources on patch use patterns and to test if food availability
can overcome structural constraints on patch use. We carried out a patch-use survey of two carnivores: the beech marten (Martes foina) and the badger (Meles meles) in a sample of 39 woodland patches in a fragmented landscape in central Italy. We used the logistic model to investigate
the relative effects on carnivore distribution of patch, patch neighbourhood and landscape scale variables as well as the
relative abundance of food resources. Our results show how carnivore movements in fragmented landscapes are determined not
only by patch/landscape structure but also by the relative abundance of food resources. The important take-home message of
our research is that, within certain structural limits (e.g. within certain limits of patch isolation), by modifying the relative
amount of resources and their distribution, it is possible to increase suitability in smaller/relatively isolated patches.
Conversely, however, there are certain thresholds above which an increase in resources will not achieve high probability of
presence. Our findings have important and generalizable consequences for highly fragmented landscapes in areas where it may
not be possible to increase patch sizes and/or reduce isolation so, for instance, forest regimes that will increase resource
availability could be implemented.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献