Diversity of EU habitat types is correlated with geography more than
climate and human pressure
Abstract
Aims: Habitat richness, i.e. the diversity of ecosystem types, is a
complex, spatially explicit aspect of biodiversity, which is affected by
bioclimatic, geographic and anthropogenic variables. The distribution of
habitat types is a key component for understanding broad-scale
biodiversity and for developing conservation strategies. To test which
factors are related with habitat richness we used EU habitat
distribution data to answer the following questions: i) how do
bioclimatic, geographic, and anthropogenic variables affect habitat
richness? ii) which category is the most important? iii) how do
interactions among these variables influence habitat richness and which
combinations produce the strongest interactions? Study area: European
Union (excluding Greece) plus the United Kingdom. Methods: We used the
distribution maps of 233 terrestrial habitat types defined by the
European Environmental Agency, to calculate habitat richness for the EU
10 km x 10 km grid map. We then investigated how environmental variables
affect habitat richness, using generalized linear models, generalized
additive models and boosted regression trees. Results: The main factors
associated with habitat richness were geographic variables, with
negative relationships observed for both latitude and longitude, and a
positive relationship for terrain ruggedness. Bioclimatic variables
played a secondary role, with habitat richness increasing slightly with
annual mean temperature and overall annual precipitation. An interaction
between anthropogenic variables was important: the combination of
increased landscape fragmentation and increased population density
strongly decreased habitat richness. Main conclusions: This is the first
attempt to disentangle spatial patterns of habitat richness at the
continental scale, as a key tool for protecting biodiversity. The
diversity of European habitats is correlated withgeography more than
climate and human pressure, reflecting a major component of
biogeographical patterns similar to the drivers observed at the species
level. The interaction between anthropogenic variables highlights the
need for coordinated, continental-scale management plans for
biodiversity conservation.