Habitat type richness associations with environmental variables: a case study in the Greek Natura 2000 aquatic ecosystems

Abstract

We investigated the potential associations of habitat type richness patterns with a series of environmental variables in 61 protected aquatic ecosystems of the Greek Natura 2000 network. Habitat type classification followed the Natura 2000 classification scheme.Habitat type richness was measured as the number of different habitat types in an area. To overcome a potential area effect in quantifying habitat type richness, we applied the ''moving window'' technique. The environmental variables were selected to account for some of the major threats to biodiversity, such as fragmentation, habitat loss and climate change. We run GLMs to associate habitat type richness with different combinations of climatic, spatial and topographic variables. Habitat type richness seemed to significantly associate with climatic variables, more than spatial or topographic ones. In particular, for the climatic ones, the importance of precipitation surpassed that of temperature and especially the precipitation of the wettest and driest month had a limiting contribution to richness unlike average climate estimators. Moreover, the landscape's latitude and longitude and fragmentation were significantly associated to richness. Our findings are in accordance to those observed in recent literature at lower (i.e. species) levels of ecological organization, fact showing that large-scale phenomena (such as climate change) can also be observed at the habitat type level, at least in our case. Thus, following the context of the Habitats Directive (92/43/EEC), that habitat types and not solely species of community interest should be protected and restored, this study serves as a first step towards investigating habitat type richness patterns.

Comparing the two Greek archipelagos plant species diversity and endemism patterns highlight the importance of isolation and precipitation as biodiversity drivers

“…However, precipitation may also have an important and complex role in driving the biodiversity patterns of these two archipelagos. The role of precipitation as a driver of biodiversity in Greece has been documented in Greek wetlands [ 55 ]. However, focus on climate change issues has led to the role of precipitation as a driver of ecological patterns being overshadowed by the role of temperature.…”

Precipitation dominates fire occurrence in Greece (1900–2010): its dual role in fuel build-up and dryness

“…The role of weather is complex and varies over spatiotemporal resolutions with short-term variation affecting local fire behaviour, and seasonal and inter-annual variations affecting fuel production and flammability over large areas as well as habitat type richness (Trouet et al, 2009;Falk et al, 2007;Drakou et al, 2011). The investigation of the role of either fuel or climate on the occurrence of large wildland fires has been mainly based on the assumption that these are either limited by (a) climate or (b) fuel accumulation (Meyn et al, 2007).…”

Road effects on habitat richness of the Greek Natura 2000 network

“…In total, 101 different habitat types were recognised. The habitat type richness in our case corresponds to habitats listed on Annex I of the Habitats Directive (92/43/EEC) which identifies habitat types as aspects of biodiversity for which SCI have to be proposed to be monitored (Dimopoulos et al 2006;Evans 2006;Drakou et al 2011). It is acknowledged that the habitat type affects ecosystem function, and thus it could be considered as an indicator of biodiversity (Thies and Tscharntke 1999).…”