239 research outputs found
The relative dependence of Spanish landscape pattern on environmental and geographical variables over time
The analysis of the dependence of landscape patterns on environment was carried out in order to investigate the landscape structure evolution of Spain. The underlying concept was that the dependence between landscape spatial structure and environmental factors could be gradually decreasing over time. Land cover data were recorded from aerial photo interpretation of 206 4 x 4 km(2) samples from three different years: 1956, 1984 and 1998. Geographical variables were taken into consideration together with the purely environmental ones. General Linear Models of repeated measures were then used to segregate environmental from geographical effects on the pattern of the land cover patches of the samples. Aridity, lithology and topography were the environmental factors used to analyse structural indices of landscape. Landscape composition has a higher dependence on environment than configuration. Environmental variables showed higher correlations with landscape composition and configuration than geographical variables. Ail-long them, overall the climatic aridity and topography significantly accounted for more variation than did lithology. There was a high degree of stability in land cover composition over time, with some significant exceptions. Nevertheless, the registered increase of fragmentation over time has demonstrated that configuration measures are needed to fully assess landscape change
Woodland Survey of Great Britain 1971-2001
The Woodland Survey of Great Britain is a unique data set, consisting of a detailed range of ecological
measurements at a national scale, covering a time span of 30 years. A set of 103 woods spread across
Britain were first surveyed in 1971, which were again surveyed in 2000–2003 (for convenience referred to
subsequently as the “2001 survey”). Standardised methods of describing the trees, shrubs, ground flora, soils
and general habitats present were used for both sets of surveys. The sample of 1648 plots spread through 103
woodland sites located across Britain makes it probably the most extensive quantitative ecological woodland
survey undertaken in Britain; it is also notable for the range of sites that have been revisited after such a long
interval. The data set provides a unique opportunity to explore the effects of a range of potential drivers of woodland
change that operated between 1971 and 2001. The data set is available in four discrete parts, which have
been assigned the following DOIs: doi:10.5285/4d93f9ac-68e3-49cf-8a41-4d02a7ead81a (Kirby et al., 2013b),
doi:10.5285/d6409d40-58fe-4fa7-b7c8-71a105b965b4 (Kirby et al., 2013d), doi:10.5285/fb1e474d-456b-42a9-
9a10-a02c35af10d2 (Kirby et al., 2013c), doi:10.5285/2d023ce9-6dbe-4b4f-a0cd-34768e1455ae (Kirby et al.,
2013a)
- …