TY  - JOUR
A1  - Kärcher, Oskar
A1  - Frank, Karin
A1  - Walz, Ariane
A1  - Markovic, Danijela
T1  - Scale effects on the performance of niche-based models of freshwater fish distributions
JF  - Ecological modelling : international journal on ecological modelling and engineering and systems ecolog
N2  - Niche-based species distribution models (SDMs) have become an essential tool in conservation and restoration planning. Given the current threats to freshwater biodiversity, it is of fundamental importance to address scale effects on the performance of niche-based SDMs of freshwater species’ distributions. The scale effects are addressed here in the context of hierarchical catchment ordering, considered as counterpart to coarsening grain-size by increasing grid-cell size. We combine fish occurrence data from the Danube River Basin, the hierarchical catchment ordering and multiple environmental factors representing topographic, climatic and anthropogenic effects to model fish occurrence probability across multiple scales. We focus on 1st to 5th order catchments. The spatial scale (hierarchical catchment order) only marginally influences the mean performance of SDMs, however the uncertainty of the estimates increases with scale. Key predictors and their relative importance are scale and species dependent. Our findings have useful implications for choosing proper species dependent spatial scales for river rehabilitation measures, and for conservation planning in areas where fine grain species data are unavailable.
KW  - Catchment order
KW  - Conservation planning
KW  - Danube
KW  - Generalized additive models
KW  - Species distribution modelling
Y1  - 2019
U6  - https://doi.org/10.1016/j.ecolmodel.2019.05.006
SN  - 0304-3800
SN  - 1872-7026
VL  - 405
SP  - 33
EP  - 42
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Markovic, Danijela
A1  - Walz, Ariane
A1  - Kärcher, Oskar
T1  - Scale effects on the performance of niche-based models of freshwater fish distributions: Local vs. upstream area influences
JF  - Ecological modelling : international journal on ecological modelling and engineering and systems ecolog
N2  - Niche-based species distribution models (SDMs) play a central role in studying species response to environmental change. Effective management and conservation plans for freshwater ecosystems require SDMs that accommodate hierarchical catchment ordering and provide clarity on the performance of such models across multiple scales. The scale-dependence components considered here are: (a) environment spatial structure, represented by hierarchical catchment ordering following the Strahler system; (b) analysis grain, that included 1st to 5th order catchments; and (c) response grain, the grain at which species respond most, represented by local and upstream catchment area effects. We used fish occurrence data from the Danube River Basin and various factors representing climate, land cover and anthropogenic pressures. Our results indicate that the choice of response grain local vs. upstream area effects and the choice of analysis grain, only marginally influence the performance of SDMs. Upstream effects tend to better predict fish distributions than corresponding local effects for anthropogenic and land cover factors, in particular for species sensitive to pollution. Key predictors and their relative importance are scale and species dependent. Consequently, choosing proper species dependent spatial scales and factors is imperative for effective river rehabilitation measures.
KW  - Catchment order
KW  - Conservation planning
KW  - Danube
KW  - Freshwater fish
KW  - Species distribution modelling
KW  - Upstream area
Y1  - 2019
U6  - https://doi.org/10.1016/j.ecolmodel.2019.108818
SN  - 0304-3800
SN  - 1872-7026
VL  - 411
PB  - Elsevier
CY  - Amsterdam
ER  -