scholarly journals Prioritizing habitat patches for conservation in fragmented landscapes/townscapes using network-based models and analyses

2009 ◽  
Author(s):  
Ö. Bodin
Keyword(s):  
Fragmented Landscapes ◽  
Habitat Patches

scholarly journals Modelling the effect of habitat fragmentation on range expansion in a butterfly

2009 ◽  
Vol 276 (1661) ◽  
pp. 1421-1427 ◽  
Author(s):  
Robert J Wilson ◽  
Zoe G Davies ◽  
Chris D Thomas
Keyword(s):  
Climate Change ◽  
Habitat Fragmentation ◽  
Range Expansion ◽  
Metapopulation Model ◽  
Function Model ◽  
Test Species ◽  
Fragmented Landscapes ◽  
Incidence Function Model ◽  
Habitat Patches ◽  
Model Expansion

There is an increasing need for conservation programmes to make quantitative predictions of biodiversity responses to changed environments. Such predictions will be particularly important to promote species recovery in fragmented landscapes, and to understand and facilitate distribution responses to climate change. Here, we model expansion rates of a test species (a rare butterfly, Hesperia comma ) in five landscapes over 18 years (generations), using a metapopulation model (the incidence function model). Expansion rates increased with the area, quality and proximity of habitat patches available for colonization, with predicted expansion rates closely matching observed rates in test landscapes. Habitat fragmentation constrained expansion, but in a predictable way, suggesting that it will prove feasible both to understand variation in expansion rates and to develop conservation programmes to increase rates of range expansion in such species.

scholarly journals The quality and isolation of habitat patches both determine where butterflies persist in fragmented landscapes

2001 ◽  
Vol 268 (1478) ◽  
pp. 1791-1796 ◽  
Author(s):  
J. A. Thomas ◽  
N. A. D. Bourn ◽  
R. T. Clarke ◽  
K. E. Stewart ◽  
D. J. Simcox ◽  
...  
Keyword(s):  
Fragmented Landscapes ◽  
Habitat Patches

scholarly journals Dispersers’ habitat detection and settling abilities modulate the effect of habitat amount on metapopulation resilience

2021 ◽  
Author(s):  
Louise Riotte-Lambert ◽  
Fabien Laroche
Keyword(s):  
Animal Movement ◽  
Habitat Amount ◽  
Fragmented Landscapes ◽  
Habitat Patches ◽  
Shadow Effect ◽  
Metapopulation Theory ◽  
Metapopulation Models ◽  
Mechanistic Understanding ◽  
The Relationship

Abstract Context Metapopulation theory makes useful predictions for conservation in fragmented landscapes. For randomly distributed habitat patches, it predicts that the ability of a metapopulation to recover from low occupancy level (the “metapopulation capacity”) linearly increases with habitat amount. This prediction derives from describing the dispersal between two patches as a function of their features and the distance separating them only, without interaction with the rest of the landscape. However, if individuals can stop dispersal when hitting a patch (“habitat detection and settling” ability), the rest of habitat may modulate the dispersal between two patches by intercepting dispersers (which constitutes a “shadow” effect). Objectives We aim at evaluating how habitat detection and settling ability, and the subsequent shadow effect, can modulate the relationship between the metapopulation capacity and the habitat amount in the metapopulation. Methods Considering two simple metapopulation models with contrasted animal movement types, we used analytical predictions and simulations to study the relationship between habitat amount and metapopulation capacity under various levels of dispersers’ habitat detection and settling ability. Results Increasing habitat detection and settling ability led to: (i) larger metapopulation capacity values than expected from classic metapopulation theory and (ii) concave habitat amount–metapopulation capacity relationship. Conclusions Overlooking dispersers’ habitat detection and settling ability may lead to underestimating the metapopulation capacity and misevaluating the conservation benefit of increasing habitat amount. Therefore, a further integration of our mechanistic understanding of animals’ displacement into metapopulation theory is urgently needed.

scholarly journals Quantifying the reliability of dispersal paths in connectivity networks

2015 ◽  
Vol 12 (105) ◽  
pp. 20150013 ◽  
Author(s):  
Karlo Hock ◽  
Peter J. Mumby
Keyword(s):  
Biological Systems ◽  
Fragmented Landscapes ◽  
Habitat Patches ◽  
Probabilistic Connectivity ◽  
Dispersal Routes

Many biological systems, from fragmented landscapes to host populations, can be represented as networks of connected habitat patches. Links between patches in these connectivity networks can represent equally diverse processes, from individuals moving through the landscape to pathogen transmissions or successive colonization events in metapopulations. Any of these processes can be characterized as stochastic, with functional links among patches that exist with various levels of certainty. This stochasticity then needs to be reflected in the algorithms that aim to predict the dispersal routes in these networks. Here we adapt the concept of reliability to characterize the likelihood that a specific path will be used for dispersal in a probabilistic connectivity network. The most reliable of the paths that connect two patches will then identify the most likely sequence of intermediate steps between these patches. Path reliability will be sensitive to targeted disruptions of individual links that form the path, and this can then be used to plan the interventions aimed at either preserving or disrupting the dispersal along that path. The proposed approach is general, and can be used to identify the most likely dispersal routes in various contexts, such as predicting patterns of migrations, colonizations, invasions and epidemics.

scholarly journals Seed-dispersal distributions by trumpeter hornbills in fragmented landscapes

2011 ◽  
Vol 278 (1716) ◽  
pp. 2257-2264 ◽  
Author(s):  
Johanna Lenz ◽  
Wolfgang Fiedler ◽  
Tanja Caprano ◽  
Wolfgang Friedrichs ◽  
Bernhard H. Gaese ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Agricultural Landscape ◽  
Dispersal Distance ◽  
Climatic Conditions ◽  
Fragmented Landscape ◽  
Long Distance ◽  
Frugivorous Birds ◽  
Fragmented Landscapes ◽  
Habitat Patches ◽  
Dispersal Distances

Frugivorous birds provide important ecosystem services by transporting seeds of fleshy fruited plants. It has been assumed that seed-dispersal kernels generated by these animals are generally leptokurtic, resulting in little dispersal among habitat fragments. However, little is known about the seed-dispersal distribution generated by large frugivorous birds in fragmented landscapes. We investigated movement and seed-dispersal patterns of trumpeter hornbills ( Bycanistes bucinator ) in a fragmented landscape in South Africa. Novel GPS loggers provide high-quality location data without bias against recording long-distance movements. We found a very weakly bimodal seed-dispersal distribution with potential dispersal distances up to 14.5 km. Within forest, the seed-dispersal distribution was unimodal with an expected dispersal distance of 86 m. In the fragmented agricultural landscape, the distribution was strongly bimodal with peaks at 18 and 512 m. Our results demonstrate that seed-dispersal distributions differed when birds moved in different habitat types. Seed-dispersal distances in fragmented landscapes show that transport among habitat patches is more frequent than previously assumed, allowing plants to disperse among habitat patches and to track the changing climatic conditions.

scholarly journals SIZE ISN'T EVERYTHING: THE IMPORTANCE OF SMALL HABITAT PATCHES WHEN PLANNING THE CONSERVATION OF SPECIES IN FRAGMENTED LANDSCAPES

2018 ◽  
Author(s):  
Brendan Wintle ◽  
Heini Kujala ◽  
Amy Whitehead ◽  
Atte Moilanen ◽  
Sarah Bekessy ◽  
...  
Keyword(s):  
Fragmented Landscapes ◽  
Habitat Patches

scholarly journals Effects of mis-alignment between dispersal traits and landscape structure on dispersal success in fragmented landscapes

2019 ◽  
Vol 6 (1) ◽  
pp. 181702 ◽  
Author(s):  
Justine L. Atkins ◽  
George L. W. Perry ◽  
Todd E. Dennis
Keyword(s):  
Landscape Structure ◽  
Extinction Risk ◽  
Suitable Habitat ◽  
Biological Traits ◽  
Heterogeneous Environments ◽  
Fragmented Landscapes ◽  
Habitat Patches ◽  
Trade Offs ◽  
Risk Of Predation ◽  
Dispersal Success

Dispersal is fundamental to population dynamics and hence extinction risk. The dispersal success of animals depends on the biophysical structure of their environments and their biological traits; however, comparatively little is known about how evolutionary trade-offs among suites of biological traits affect dispersal potential. We developed a spatially explicit agent-based simulation model to evaluate the influence of trade-offs among a suite of biological traits on the dispersal success of vagile animals in fragmented landscapes. We specifically chose traits known to influence dispersal success: speed of movement, perceptual range, risk of predation, need to forage during dispersal, and amount of suitable habitat required for successful settlement in a patch. Using the metric of relative dispersal success rate, we assessed how the costs and benefits of evolutionary investment in these biological traits varied with landscape structure. In heterogeneous environments with low habitat availability and scattered habitat patches, individuals with more equal allocation across the trait spectrum dispersed most successfully. Our analyses suggest that the dispersal success of animals in heterogeneous environments is highly dependent on hierarchical interactions between trait trade-offs and the geometric configurations of the habitat patches in the landscapes through which they disperse. In an applied sense, our results indicate potential for ecological mis-alignment between species' evolved suites of dispersal-related traits and altered environmental conditions as a result of rapid global change. In many cases identifying the processes that shape patterns of animal dispersal, and the consequences of abiotic changes for these processes, will require consideration of complex relationships among a range of organism-specific and environmental factors.

scholarly journals Foraging behavior and patch size distribution jointly determine population dynamics in fragmented landscapes

2021 ◽  
Author(s):  
Johannes Nauta ◽  
Yara Khaluf ◽  
Pieter Simoens ◽  
Ricardo Martinez-Garcia
Keyword(s):  
Population Dynamics ◽  
Foraging Behavior ◽  
Habitat Loss ◽  
Optimal Foraging ◽  
Ecosystem Stability ◽  
Fragmented Landscapes ◽  
Predator Prey ◽  
Habitat Patches ◽  
Animal Populations ◽  
Per Se

Increased fragmentation caused by habitat loss presents a major threat to the persistence of animal populations. Whereas the negative effects of habitat loss on biodiversity are well-known, the effects of fragmentation per se on population dynamics and ecosystem stability remain less understood. How fragmentation affects populations is strongly determined by the rate at which individuals can move between separated habitat patches within the fragmented landscape. Here, we use a computational, spatially explicit predator-prey model to investigate how the interplay between fragmentation per se and optimal foraging behavior influences predator-prey interactions and, ultimately, ecosystem stability. We study cases where prey occupies isolated habitat patches and let predators disperse between patches following a Lévy random walk. Our results show that both the Lévy exponent and the degree of fragmentation strongly determine coexistence probabilities. Brownian and ballistic predators go extinct in highly fragmented landscapes and only scale-free predators can coexist with prey. Furthermore, our results reveal that predation causes irreversible loss of prey habitat in highly fragmented landscapes due to the overexploitation of smaller patches. Moreover, our results show that predator movement can reduce, but not prevent not minimize, the amount of irreversibly lost habitat. Our results suggest that incorporating optimal foraging theory into population- and landscape ecology models is crucial to assess the impact of fragmentation on biodiversity and ecosystem stability.

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