Remote assessment of the effects of rural abandonment on habitat quality to improve the monitoring of High Nature Value Farmland in Europe

Highlighting the convergence between nature conservation and rural development policies in the EU, the High Nature Value Farmland (HNVF) concept acknowledges the importance of many rural landscapes and agro-ecosystems for the conservation of biodiversity and the provision of ecosystem services in the wider European countryside. The concept comprises areas where farming supports species and habitats of high conservation relevance and/or high levels biodiversity and ecological value through high proportion of managed semi-natural vegetation (e.g. woodlands, meadows) within mosaics of agricultural habitats (Andersen et al., 2003; Paracchini et al., 2008). Recent trends in agricultural management have favoured specialized land allocation and intensification in some EU regions, whereas others (e.g. much of Southern Europe) have been suffering the abandonment of rural activities in mountains and marginal areas. These contrasting pathways have both contributed to deeply reshaping landscape structure and are impacting on habitat quantity, quality and distribution. In such context, there’s a growing interest in maintaining extensive farming practices, thus contributing to preserve habitat and species diversity and other structural/functional features of rural landscapes (Lomba et al., 2012).

Land cover and habitat change (both quantity and quality) can efficiently be tracked through remote sensing, including both structural approaches (e.g. land cover or habitat mapping) and functional assessments (e.g. ecosystem productivity or phenology; Nagendra et al., 2012). When complemented with in-field biodiversity data, remote sensing methods can provide valuable information on several indicators of habitat quality. In Mediterranean marginal farmland, such an integrative approach can efficiently assess the implications of rural abandonment for habitat quantity, distribution and quality. Here we focus on the assessment of habitat quality for native oak woodlands, which take part in successional pathways fostered by farmland abandonment. We use a modelling framework that combines land cover and habitat maps from remote sensing images, ancillary data (e.g. VHR topographic maps), and in-field information on plant community structure to assess habitat quality for a focal habitat class. Parameters related to plant community structure (from species diversity to proportions of functional groups) are used as proxies of habitat quality in relation to land use dynamics (e.g. time since abandonment) and successional pathways (e.g. type of land use at the onset of abandonment). We present results of a local case-study from HNV mountain farmland in Portugal, developed under a common general framework developed in the FP7 project BIO_SOS. We argue that testing the approach over a wide range of environmental and social-ecological settings will demonstrate its potential to tackle these and other issues related to impacts of pressures on habitat quality.

Angela Lomba is supported by the Portuguese Science and Technology Foundation (FCT) through Post Doc Grant SFRH/BPD/ 80747/2011.This research was developed in the context of the FP7 project “BIO_SOS - Biodiversity Multisource Monitoring System: from Space TO Species” (FP7-SPA-2010-1-263435).