Spatial predictions of bird species distribution as regional essential
biodiversity variables (SD EBVs): a bird perspective in Swiss Alps
Abstract
This study aims at examining the applicability of a novel approach based
on species distribution models (SDMs) to establish spatial predictions
of EBVs for birds based on bird diversity metrics such as the
distributions of properties of key bird habitats. A major objective of
this study is to build bird SDMs which can be used to derive spatial
EBVs for bird species at a regional scale. We used as predictors 16
environmental variables that are known to be ecologically meaningful for
birds at 100 m spatial resolution, including two bioclimatic variables
(Bio17 = precipitation of driest quarter and Bio7 = temperature annual
range) for three periods of ‘current’, ‘future 2050’, and ‘future 2070’,
eleven land-cover (land use) predictors, the normalized difference
vegetation index (NDVI), and two topographic variables (slope and
topography). We used multiple modeling techniques to build presence-only
SDMs relating bird presence to environmental features of each species.
Here, we show that the suitability estimated according to the SDMs can
be used as a spatial ‘species distribution’ EBV (SD EBV) and reflect the
habitat quality and trends in land use and climatic impacts on
populations of bird species. These developments could facilitate
monitoring of bird species across space and time, ultimately helping to
identify priority conservation areas, estimate habitat suitability and
provide early warning signs regarding bird distribution trends. In
general, bioclimatic variables, topography and forest structure were
identified to have important ties to the species probability maps
generated on the basis of the SDMs, signifying a dominant role of
bioclimatic variable Bio17 in the development of habitat suitability
patterns. Keywords: Essential biodiversity variables, species
distribution modelling, species distribution essential biodiversity
variables (SDEBV), bird species, Swiss Alps