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Survival in patchy landscapes: the interplay between dispersal, habitat loss and fragmentation.

Niebuhr BB, Wosniack ME, Santos MC, Raposo EP, Viswanathan GM, da Luz MG, Pie MR - Sci Rep (2015)

Bottom Line: Such landscape changes can lead to the deleterious impact of a significant drop in the number of species, caused by critically reduced survival rates for organisms.By considering basic ecological processes, such as predation, starvation (outside the habitat area), and competition, together with dispersal movement as a link among habitat areas, we show that a higher survival rate is achieved in instances with a lower number of patches of larger areas.In particular, they have important implications for conservation planning and ecosystem management, including the design of specific features of conservation areas in order to enhance landscape connectivity and population viability.

View Article: PubMed Central - PubMed

Affiliation: Laboratório de Dinâmica Evolutiva e Sistemas Complexos, Departamento de Zoologia, Universidade Federal do Paraná, CP 19020, 81531-980, Curitiba-PR, Brazil.

ABSTRACT
Habitat loss and fragmentation are important factors determining animal population dynamics and spatial distribution. Such landscape changes can lead to the deleterious impact of a significant drop in the number of species, caused by critically reduced survival rates for organisms. In order to obtain a deeper understanding of the threeway interplay between habitat loss, fragmentation and survival rates, we propose here a spatially explicit multi-scaled movement model of individuals that search for habitat. By considering basic ecological processes, such as predation, starvation (outside the habitat area), and competition, together with dispersal movement as a link among habitat areas, we show that a higher survival rate is achieved in instances with a lower number of patches of larger areas. Our results demonstrate how movement may counterbalance the effects of habitat loss and fragmentation in altered landscapes. In particular, they have important implications for conservation planning and ecosystem management, including the design of specific features of conservation areas in order to enhance landscape connectivity and population viability.

No MeSH data available.


Related in: MedlinePlus

(A) Illustration of habitat amounts and fragmentation levels in distinct simulated landscapes. An example of a typical movement dynamics in a search event is shown. (B–D) Average search quantities versus the movement strategy (represented by the Lévy exponent μ) for different fragmentation degrees (from a less fragmented, Np = 5, to a highly fragmented, Np = 50), in a scenario in which the amount of habitat is AH/AT = 10%: (B) number of patches visited; (C) time outside patches; (D) survival time. For comparison, the insets show the case with no fragmentation (Np = 1).
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f1: (A) Illustration of habitat amounts and fragmentation levels in distinct simulated landscapes. An example of a typical movement dynamics in a search event is shown. (B–D) Average search quantities versus the movement strategy (represented by the Lévy exponent μ) for different fragmentation degrees (from a less fragmented, Np = 5, to a highly fragmented, Np = 50), in a scenario in which the amount of habitat is AH/AT = 10%: (B) number of patches visited; (C) time outside patches; (D) survival time. For comparison, the insets show the case with no fragmentation (Np = 1).

Mentions: We performed extensive simulations for distinct parameters values and landscape configurations shown in Fig. 1A. In Fig. 1 we consider the total amount of habitat area (AH) as 10% of the landscape area (AT), but we should also stress that, for habitat areas equal to 1%, 20% and 30% of AT, we have found similar qualitative behaviors. Also, the situation where the number of habitat patches (Np) is 1—shown in the insets of Fig. 1B–D—is useful as a comparison reference since it illustrates the effects of the hostile matrix and movement dynamics when fragmentation is absent (once leaving the sole patch, the searcher can reenter it only after reaching the environment borders—see Methods).


Survival in patchy landscapes: the interplay between dispersal, habitat loss and fragmentation.

Niebuhr BB, Wosniack ME, Santos MC, Raposo EP, Viswanathan GM, da Luz MG, Pie MR - Sci Rep (2015)

(A) Illustration of habitat amounts and fragmentation levels in distinct simulated landscapes. An example of a typical movement dynamics in a search event is shown. (B–D) Average search quantities versus the movement strategy (represented by the Lévy exponent μ) for different fragmentation degrees (from a less fragmented, Np = 5, to a highly fragmented, Np = 50), in a scenario in which the amount of habitat is AH/AT = 10%: (B) number of patches visited; (C) time outside patches; (D) survival time. For comparison, the insets show the case with no fragmentation (Np = 1).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493700&req=5

f1: (A) Illustration of habitat amounts and fragmentation levels in distinct simulated landscapes. An example of a typical movement dynamics in a search event is shown. (B–D) Average search quantities versus the movement strategy (represented by the Lévy exponent μ) for different fragmentation degrees (from a less fragmented, Np = 5, to a highly fragmented, Np = 50), in a scenario in which the amount of habitat is AH/AT = 10%: (B) number of patches visited; (C) time outside patches; (D) survival time. For comparison, the insets show the case with no fragmentation (Np = 1).
Mentions: We performed extensive simulations for distinct parameters values and landscape configurations shown in Fig. 1A. In Fig. 1 we consider the total amount of habitat area (AH) as 10% of the landscape area (AT), but we should also stress that, for habitat areas equal to 1%, 20% and 30% of AT, we have found similar qualitative behaviors. Also, the situation where the number of habitat patches (Np) is 1—shown in the insets of Fig. 1B–D—is useful as a comparison reference since it illustrates the effects of the hostile matrix and movement dynamics when fragmentation is absent (once leaving the sole patch, the searcher can reenter it only after reaching the environment borders—see Methods).

Bottom Line: Such landscape changes can lead to the deleterious impact of a significant drop in the number of species, caused by critically reduced survival rates for organisms.By considering basic ecological processes, such as predation, starvation (outside the habitat area), and competition, together with dispersal movement as a link among habitat areas, we show that a higher survival rate is achieved in instances with a lower number of patches of larger areas.In particular, they have important implications for conservation planning and ecosystem management, including the design of specific features of conservation areas in order to enhance landscape connectivity and population viability.

View Article: PubMed Central - PubMed

Affiliation: Laboratório de Dinâmica Evolutiva e Sistemas Complexos, Departamento de Zoologia, Universidade Federal do Paraná, CP 19020, 81531-980, Curitiba-PR, Brazil.

ABSTRACT
Habitat loss and fragmentation are important factors determining animal population dynamics and spatial distribution. Such landscape changes can lead to the deleterious impact of a significant drop in the number of species, caused by critically reduced survival rates for organisms. In order to obtain a deeper understanding of the threeway interplay between habitat loss, fragmentation and survival rates, we propose here a spatially explicit multi-scaled movement model of individuals that search for habitat. By considering basic ecological processes, such as predation, starvation (outside the habitat area), and competition, together with dispersal movement as a link among habitat areas, we show that a higher survival rate is achieved in instances with a lower number of patches of larger areas. Our results demonstrate how movement may counterbalance the effects of habitat loss and fragmentation in altered landscapes. In particular, they have important implications for conservation planning and ecosystem management, including the design of specific features of conservation areas in order to enhance landscape connectivity and population viability.

No MeSH data available.


Related in: MedlinePlus