The objective of this paper was the development of a methodology for the classification of digital aerial images, which, with the aid of object-based classification and the Normalized Difference Vegetation Index (NDVI), can quantify agricultural areas, by using algorithms of expert classification, with the aim of improving the final results of thematic classifications.
Knowledge of the factors determining species distributions is essential for developing conservation strategies. Sandgrouse Pterocles alchata and P. orientalis are threatened in Spain, the stronghold of European populations. Spatial modelling was used to: (1) assess the relative importance of abiotic, anthropogenic and geographical factors in the distribution of both sandgrouse species, (2) determine the most important anthropogenic predictors for each species occurrence, and (3) identify areas where conservation efforts should be prioritized.
The spatial structure, functionality and dynamics of forest landscapes in peninsular Spain and the Balearic Islands were compared over the last five decades. Two particular features were studied in the sample sites: forest connectivity for wildlife and areas burnt by wildfires. 191 Squares, each 4km×4km, were selected from the SISPARES (the monitoring framework designed to evaluate the trends in the structure of Spanish rural landscapes) environmental strata.
Communal forests, or Montes Veciñais en Man Común (MVMC), are a specific form of communal land tenure and a singular legal category in Galicia. The growing demographic decline in rural areas and, particularly, in inner areas of Galicia has led to a decrease in the economic interest of forest resources. The complexity of the different management modes or levels of organization of forest communities cannot be explained through a homogeneous interpretation.
The natural regeneration in the dehesa has been object of numerous studies, due to the ecologic and economic importance of such ecosystems. In this work is exposed a test of acorns germination of Quercus ilex L. subsp. ballota (Desf.) Samp, in the North of Córdoba (Spain), under three environmental conditions corresponding to the most traditional land uses of the dehesa: grazing, cereal sowing and fallow, each one with a different vegetal cover. A fourth group of acorns was placed in a tree nursery under controlled conditions.
Question: Small and marginal forest populations are a focus of attention because of their high biodiversity value as well as the risk of population decline and loss. In this context, we ask to what extent a small, marginal Quercus suber (Cork oak) population located in the eastern Iberian Peninsula (Valencia, Spain) has the capacity for self‐regeneration and what are the factors that determine its recruitment variability. Location: Quercus suber forest in Pinet (Valencia, Spain).
AIM: Efforts to adapt conservation to climate change are hampered by a scarcity of studies of community‐level ecological responses. We examined temporal (40 years) and spatial (1700 m elevational gradient) variation in butterfly communities, aiming to test whether the composition of communities in terms of species' thermal envelopes tracked regional warming, and whether local habitat influenced community responses to climate variation. LOCATION: Sierra de Guadarrama (central Spain).
Forestry variables are usually calculated at a forest management unit scale. However, a region's forestry sector is affected by various other factors that interact over space and time, many of which are not directly associated to silvicultural activities but nonetheless play an important part in its development from a socio-economic or environmental point of view.
Air temperature can be estimated from remote sensing by combining information in thermal infrared and optical wavelengths. The empirical TVX algorithm is based on an estimated linear relationship between observed Land Surface Temperature (LST) and a Spectral Vegetation Index (NDVI). Air temperature is assumed to be equal to the LST corresponding to the effective full vegetation cover, and is found by extrapolating the line to a maximum value of NDVIₘₐₓ. The algorithm has been tested and reported in the literature previously.