Indicators of the impact of land use changes using large-scale bird surveys: Land abandonment in a Mediterranean region

Herrando S., Anton M., Sarda-Palomera F., Bota G., Gregory R.D., Brotons L. (2014) Indicators of the impact of land use changes using large-scale bird surveys: Land abandonment in a Mediterranean region. Ecological Indicators. 45: 235-244.
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Doi: 10.1016/j.ecolind.2014.04.011

Resum:

Developing sound indicators of biodiversity impact has been identified as a critical step towards our understanding of how global change components are affecting the environment across the globe. Land abandonment is recognized as a major component of global change in the Mediterranean basin, however, we lack adequate, quantitative, indicators of its impact on biodiversity. An appealing approach to develop biodiversity indicators is the use of large-scale bird monitoring projects, an important source of information that is already available in many countries. In this study we develop a method to quantify the impact of the two main processes associated with land abandonment in the Mediterranean region, namely the abandonment of farmland, which produces a shift from cultivated land to open natural habitats, and the encroachment by vegetation usually associated with reductions in livestock grazing and wood harvesting practices. We used data from bird atlas and monitoring schemes in Catalonia (north-east Iberian Peninsula) to characterize species' population response to these processes by means of detecting quantitative changes in relative abundances along a gradient ranging from habitats not affected by a given driving force to those that arise as a consequence of such force. We then generated multi-species indicators of the impact of these land use changes using these specific population responses to calibrate the relative contribution of each species in the composite index. The temporal patterns depicted by the two indicators in the period 2002-2011 show that vegetation encroachment did have a significant impact on bird communities, whereas any noticeable effect of farmland abandonment on bird populations was observed. The methodology proposed here could be employed to develop indicators capable to track biological impacts of land use change on an annual basis and inform decision-makers about the rate of increase or decrease on wildlife populations. © 2014 Elsevier Ltd.

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Is response to fire influenced by dietary specialization and mobility? A comparative study with multiple animal assemblages

Santos X., Mateos E., Bros V., Brotons L., De Mas E., Herraiz J.A., Herrando S., Mino A., Olmo-Vidal J.M., Quesada J., Ribes J., Sabate S., Sauras-Yera T., Serra A., Ramon Vallejo V., Vinolas A. (2014) Is response to fire influenced by dietary specialization and mobility? A comparative study with multiple animal assemblages. PLoS ONE. 9: 0-0.
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Doi: 10.1371/journal.pone.0088224

Resum:

Fire is a major agent involved in landscape transformation and an indirect cause of changes in species composition. Responses to fire may vary greatly depending on life histories and functional traits of species. We have examined the taxonomic and functional responses to fire of eight taxonomic animal groups displaying a gradient of dietary and mobility patterns: Gastropoda, Heteroptera, Formicidae, Coleoptera, Araneae, Orthoptera, Reptilia and Aves. The fieldwork was conducted in a Mediterranean protected area on 3 sites (one unburnt and two burnt with different postfire management practices) with five replicates per site. We collected information from 4606 specimens from 274 animal species. Similarity in species composition and abundance between areas was measured by the Bray-Curtis index and ANOSIM, and comparisons between animal and plant responses by Mantel tests. We analyze whether groups with the highest percentage of omnivorous species, these species being more generalist in their dietary habits, show weak responses to fire (i.e. more similarity between burnt and unburnt areas), and independent responses to changes in vegetation. We also explore how mobility, i.e. dispersal ability, influences responses to fire. Our results demonstrate that differences in species composition and abundance between burnt and unburnt areas differed among groups. We found a tendency towards presenting lower differences between areas for groups with higher percentages of omnivorous species. Moreover, taxa with a higher percentage of omnivorous species had significantly more independent responses of changes in vegetation. High- (e.g. Aves) and low-mobility (e.g. Gastropoda) groups had the strongest responses to fire (higher R scores of the ANOSIM); however, we failed to find a significant general pattern with all the groups according to their mobility. Our results partially support the idea that functional traits underlie the response of organisms to environmental changes caused by fire. © 2014 Santos et al.

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