RESUMO
Given the recent strengthening of wetland restoration and protection policies in France, there is need to develop rapid assessment methods that provide a cost-effective way to assess losses and gains of wetland functions. Such methods have been developed in the US and we tested six of them on a selection of contrasting wetlands in the Isère watershed. We found that while the methods could discriminate sites, they did not always give consistent rankings, thereby revealing the different assumptions they explicitly or implicitly incorporate. The US assessment methods commonly use notions of "old-growth" or "pristine" to define the benchmark conditions against which to assess wetlands. Any reference-based assessment developed in the US would need adaptation to work in the French context. This could be quite straightforward for the evaluation of hydrologic variables as scoring appears to be consistent with the best professional judgment of hydrologic condition made by a panel of French local experts. Approaches to rating vegetation condition and landscape context, however, would require substantial reworking to reflect a novel view of reference standard. Reference standard in the European context must include acknowledgement that many of the best condition and biologically important wetland types in France are the product of intensive, centuries-long management (mowing, grazing, etc.). They must also explicitly incorporate the recent trend in ecological assessment to focus particularly on the wetland's role in landscape-level connectivity. These context-specific, socio-cultural dimensions must be acknowledged and adjusted for when adapting or developing wetland assessment methods in new cultural contexts.
Assuntos
Conservação dos Recursos Naturais , Monitoramento Ambiental/métodos , Água Doce , Áreas Alagadas , Ecologia , Monitoramento Ambiental/normas , França , HidrologiaRESUMO
Species occurrence data provide crucial information for biodiversity studies in the current context of global environmental changes. Such studies often rely on a limited number of occurrence data collected in the field and on pseudo-absences arbitrarily chosen within the study area, which reduces the value of these studies. To overcome this issue, we propose an alternative method of prospection using geo-located street view imagery (SVI). Following a standardised protocol of virtual prospection using both vertical (aerial photographs) and horizontal (SVI) perceptions, we have surveyed 1097 randomly selected cells across Spain (0.1x0.1 degree, i.e. 20% of Spain) for the presence of Arundo donax L. (Poaceae). In total we have detected A. donax in 345 cells, thus substantially expanding beyond the now two-centuries-old field-derived record, which described A. donax only 216 cells. Among the field occurrence cells, 81.1% were confirmed by SVI prospection to be consistent with species presence. In addition, we recorded, by SVI prospection, 752 absences, i.e. cells where A. donax was considered absent. We have also compared the outcomes of climatic niche modeling based on SVI data against those based on field data. Using generalized linear models fitted with bioclimatic predictors, we have found SVI data to provide far more compelling results in terms of niche modeling than does field data as classically used in SDM. This original, cost- and time-effective method provides the means to accurately locate highly visible taxa, reinforce absence data, and predict species distribution without long and expensive in situ prospection. At this time, the majority of available SVI data is restricted to human-disturbed environments that have road networks. However, SVI is becoming increasingly available in natural areas, which means the technique has considerable potential to become an important factor in future biodiversity studies.