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ZURELL Damaris

  • Geography Department, Humboldt-Universität zu Berlin, Berlin, Germany
  • Biodiversity, Biogeography, Climate change, Demography, Dispersal & Migration, Habitat selection, Macroecology, Spatial ecology, Metacommunities & Metapopulations, Species distributions, Theoretical ecology
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Educational and work
2007 Diplom (MSc) in Geoecology, Univ. Potsdam/Germany 2011 PhD on modelling species range dynamics, Univ. Potsdam/Germany, Environmental Modelling Lab 2011-2014 Postdoc on animal movement ecology, Univ. Potsdam/Germany, Plant Ecology and Nature Conservation Lab 2014-2018 Postdoc/staff research on community ecology and macroecology, Swiss Federal Research Inst. WSL/Switzerland, Dynamic Macroecology Group since 2018 Junior research group leader on biodiversity modelling, Humboldt-Univ. Berlin/Germany I am fascinated by the question why species and individuals are where they are, how they get there and how they manage to sustain. This is central to understanding how they will respond to changes in their abiotic and biotic environment, for example due to climate change. In my team, we tackle research questions across several spatial and temporal scales. For example, we study drivers of broad-scale species distributions, of population dynamics as well as individual fitness, and their interplay with inter- and intraspecific interactions and life-history trade-offs. Modelling is a major part of our work, and we dedicate a lot of time to testing and improving existing methods for biodiversity modelling.

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19 Aug 2020
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Three points of consideration before testing the effect of patch connectivity on local species richness: patch delineation, scaling and variability of metrics

Recommended by based on reviews by 3 anonymous reviewers

Good practice guidelines for testing species-isolation relationships in patch-matrix systems

Conservation biology is strongly rooted in the theory of island biogeography (TIB). In island systems where the ocean constitutes the inhospitable matrix, TIB predicts that species richness increases with island size as extinction rates decrease with island area (the species-area relationship, SAR), and species richness increases with connectivity as colonisation rates decrease with island isolation (the species-isolation relationship, SIR)[1]. In conservation biology, patches of habitat (habitat islands) are often regarded as analogous to islands within an unsuitable matrix [2], and SAR and SIR concepts have received much attention as habitat loss and habitat fragmentation are increasingly threatening biodiversity [3,4].
The existence of SAR in patch-matrix systems has been confirmed in several studies, while the relative importance of SIR remains debated [2,5] and empirical evidence is mixed. For example, Thiele et al. [6] showed that connectivity effects are trait specific and more important to explain species richness of short-distant dispersers and of specialist species for which the matrix is less permeable. Some authors have also cautioned that the relative support for or against the existence of SIR may depend on methodological decisions related to connectivity metrics, patch classification, scaling decisions and sample size [7].
In this preprint, Laroche and colleagues [8] argue that methodological limits should be fully understood before questioning the validity of SIR in patch-matrix systems. In consequence, they used a virtual ecologist approach [9] to qualify different methodological aspects and derive good practice guidelines related to patch delineation, patch connectivity indices, and scaling of indices with species dispersal distance.
Laroche et al. [8] simulated spatially-explicit neutral meta-communities with up to 100 species in artificial fractal (patch-matrix) landscapes. Each habitat cell could hold up to 100 individuals. In each time step, some individuals died and were replaced by an individual from the regional species pool depending on relative local and regional abundance as well as dispersal distance to the nearest source habitat cell. Different scenarios were run with varying degrees of spatial autocorrelation in the fractal landscape (determining the clumpiness of habitat cells), the proportion of suitable habitat, and the species dispersal distances (with all species showing the same dispersal distance). Laroche and colleagues then sampled species richness in the simulated meta-communities, computed different local connectivity indices for the simulated landscapes (Buffer index with different radii, dIICflux index and dF index, and, finally, related species richness to connectivity.
The complex simulations allowed Laroche and colleagues [8] to test how methodological choices and landscape features may affect SIR. Overall, they found that patch delineation is crucial and should be fine enough to exclude potential within-patch dispersal limitations, and the scaling of the connectivity indices (in simplified words, the window of analyses) should be tailored to the dispersal distance of the species group. Of course, tuning the scaling parameters will be more complicated when dispersal distances vary across species but overall these results corroborate empirical findings that SIR effects are trait specific [6]. Additionally, the results by Laroche and colleagues [8] indicated that indices based on Euclidian rather than topological distance are more performant and that evidence of SIR is more likely if Buffer indices are highly variable between sampled patches.
Although the study is very technical due to the complex simulation approach and the different methods tested, I hope it will not only help guiding methodological choices but also inspire ecologists to further test or even revisit SIR (and SAR) hypotheses for different systems. Also, Laroche and colleagues propose many interesting avenues that could still be explored in this context, for example determining the optimal grid resolution for the patch delineation in empirical studies.

References

[1] MacArthur, R.H. and Wilson, E.O. (1967) The theory of island biogeography. Princeton University Press, Princeton.
[2] Fahrig, L. (2013) Rethinking patch size and isolation effects: the habitat amount hypothesis. Journal of Biogeography, 40(9), 1649-1663. doi: 10.1111/jbi.12130
[3] Hanski, I., Zurita, G.A., Bellocq, M.I. and Rybicki J (2013) Species–fragmented area relationship. Proceedings of the National Academy of Sciences U.S.A., 110(31), 12715-12720. doi: 10.1073/pnas.1311491110
[4] Giladi, I., May, F., Ristow, M., Jeltsch, F. and Ziv, Y. (2014) Scale‐dependent species–area and species–isolation relationships: a review and a test study from a fragmented semi‐arid agro‐ecosystem. Journal of Biogeography, 41(6), 1055-1069. doi: 10.1111/jbi.12299
[5] Hodgson, J.A., Moilanen, A., Wintle, B.A. and Thomas, C.D. (2011) Habitat area, quality and connectivity: striking the balance for efficient conservation. Journal of Applied Ecology, 48(1), 148-152. doi: 10.1111/j.1365-2664.2010.01919.x
[6] Thiele, J., Kellner, S., Buchholz, S., and Schirmel, J. (2018) Connectivity or area: what drives plant species richness in habitat corridors? Landscape Ecology, 33, 173-181. doi: 10.1007/s10980-017-0606-8
[7] Vieira, M.V., Almeida-Gomes, M., Delciellos, A.C., Cerqueira, R. and Crouzeilles, R. (2018) Fair tests of the habitat amount hypothesis require appropriate metrics of patch isolation: An example with small mammals in the Brazilian Atlantic Forest. Biological Conservation, 226, 264-270. doi: 10.1016/j.biocon.2018.08.008
[8] Laroche, F., Balbi, M., Grébert, T., Jabot, F. and Archaux, F. (2020) Three points of consideration before testing the effect of patch connectivity on local species richness: patch delineation, scaling and variability of metrics. bioRxiv, 640995, ver. 5 peer-reviewed and recommended by PCI Ecology. doi: 10.1101/640995
[9] Zurell, D., Berger, U., Cabral, J.S., Jeltsch, F., Meynard, C.N., Münkemüller, T., Nehrbass, N., Pagel, J., Reineking, B., Schröder, B. and Grimm, V. (2010) The virtual ecologist approach: simulating data and observers. Oikos, 119(4), 622-635. doi: 10.1111/j.1600-0706.2009.18284.x

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ZURELL Damaris

  • Geography Department, Humboldt-Universität zu Berlin, Berlin, Germany
  • Biodiversity, Biogeography, Climate change, Demography, Dispersal & Migration, Habitat selection, Macroecology, Spatial ecology, Metacommunities & Metapopulations, Species distributions, Theoretical ecology
  • recommender

Recommendation:  1

Reviews:  0

Educational and work
2007 Diplom (MSc) in Geoecology, Univ. Potsdam/Germany 2011 PhD on modelling species range dynamics, Univ. Potsdam/Germany, Environmental Modelling Lab 2011-2014 Postdoc on animal movement ecology, Univ. Potsdam/Germany, Plant Ecology and Nature Conservation Lab 2014-2018 Postdoc/staff research on community ecology and macroecology, Swiss Federal Research Inst. WSL/Switzerland, Dynamic Macroecology Group since 2018 Junior research group leader on biodiversity modelling, Humboldt-Univ. Berlin/Germany I am fascinated by the question why species and individuals are where they are, how they get there and how they manage to sustain. This is central to understanding how they will respond to changes in their abiotic and biotic environment, for example due to climate change. In my team, we tackle research questions across several spatial and temporal scales. For example, we study drivers of broad-scale species distributions, of population dynamics as well as individual fitness, and their interplay with inter- and intraspecific interactions and life-history trade-offs. Modelling is a major part of our work, and we dedicate a lot of time to testing and improving existing methods for biodiversity modelling.