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This study has quantitatively mapped the distributions and peak above-ground foliar biomass of the 1000 most prevalent plant and tree species in Great Britain (GB) on a 1 x 1 km(2) grid. Each 1 x 1 km(2) grid cell was assigned to one of 56 land classes on the basis of environmental and land cover attributes. The mean occurrence and cover area of specific plant species within each land class was derived from the results of the Countryside Survey 1990 [Barr CJ, Bunce RGH, Clarke RT, Fuller RM, Furse MT, Gillespie MK, et al. Countryside Survey 1990 Main Report. HMSO, 1993]. Species-specific biomass conversion factors, relating above-ground living plant biomass (excluding tree timber) to a unit of ground area, were used to convert cover areas into species biomass. British totals of species cover area and biomass were then calculated. Lolium perenne (perennial rye grass), Triticum aestivurn (wheat) and Calluna vulgaris Ling (heather) covered the greatest areas of GB (26,811, 25,378 and 14,359 km(2), respectively). During summer (prior to harvest), L. perenne contributed 20% of the peak standing biomass in Britain (25.6 Mt), followed by T aestivum (18.8 Mt) and Hordeum vulgare (barley) (15.5 Mt). Picea sitchensis (Sitka spruce) was the dominant tree species in GB with the fourth highest peak foliar biomass (7.3 Mt). In total, 70 species accounted for 90% of the estimated summer biomass of GB. P. sitchensis and C. vulgaris dominated winter biomass. Predictive biomass distributions can be plotted for each species and examples of lowland and upland species are given. The predictions correspond well with known habitat preferences. Monthly variations in total biomass have also been plotted. (c) 2008 Elsevier Ltd. All rights reserved.

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 × 4 km2 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. Among 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.

An urban land-cover classification of the 900 km2 comprising the UK West Midland metropolitan area was generated for the purpose of facilitating stratified environmental survey and sampling. The classification grouped the 900 km2 into eight urban land-cover classes. Input data to the classification algorithms were derived from spatial land-cover data obtained from the UK Centre for Ecology and Hydrology, and from the UK Ordnance Survey. These data provided a description of each km2 in terms of the contributions to the land cover of 25 attributes (e.g. open land, urban, villages, motorway, etc.). The dimensionality of the land-cover dataset was reduced using principal component analysis, and eight urban classes were derived by cluster analysis using an agglomeration technique on the extracted components. The resulting urban land-cover classes reflected groupings of 1 km2 pixels with similar urban land morphology. Uncertainties associated with this agglomerative classification were investigated in detail using fuzzy-type analyses. Our study is the first report of a quantitative investigation of uncertainty associated with a classification of this type. The resulting classification for the UK West Midland metropolitan area offers an impartial basis for a wide range of environmental and ecological surveys. The methods used can be adapted readily to other metropolitan areas where generic urban features (e.g. roads, housing density) are gridded.

Presence of higher plant species was recorded in 1455 permanently marked quadrats located across Britain in 1978, 1990 and 1998 in a stratified, random sample of 259 1 km squares. Significant increases and decreases in frequency of each species were summarised as changes in the representation of simple traits, each of which had an established relationship with varying levels of fertility or disturbance. By testing the null hypothesis that the trait values represented among increasing or decreasing species were a random draw from the 1978 species pool, we determined the consistency of botanical change with changes in land-use in different vegetation types and landscape locations across Britain. Overall, 63% of significant changes in species occupancy were decreases and 37% increases. Trait changes were largely consistent with the impact of increased nutrient availability across vegetation types associated with inherently low fertility, such as infertile grassland, heath, bog and moorland. Linear habitats in lowland Britain saw trait changes consistent with secondary succession. Although trait changes were highly consistent with eutrophication in upland vegetation, the identity of the changing species left open the possibility that increased N deposition, sheep grazing intensity and local improvement could all have played a part. Recent changes in common plant species across Britain suggest that objectives for large-scale restoration and maintenance of plant communities must address four problems: (a) the increasing scarcity of stress-tolerant species in lowland species pools, (b) exploitation and maintenance of species populations on habitat fragments and linear features in the lowlands, (c) the spread and persistence of generalist species in upland Britain, (d) systemic nutrient enrichment in both lowland and upland environments.

Assessment of factors influencing woodland vegetation composition across Britain was made using multivariate techniques to analyse data gathered during the 1971 National Woodland Survey. Indirect gradient analysis (unconstrained ordination using detrended correspondence analysis) suggested a gradient strongly associated with nutrient availability and pH. Direct gradient analysis (constrained ordination using canonical correspondence analysis) and variation partitioning were used with over 250 ecophysiologically relevant variables, including climatic, geographical, soil and herbivore data, to model the response of woodland vegetation. Although there was a high degree of multicollinearity between environmental variables, analysis revealed the vegetation composition of surveyed woodlands to be primarily structured by geographical, climatic and soil gradients, in particular rainfall, soil pH and accumulated temperature. The woods have recently been resurveyed. The results of this analysis therefore provide a baseline against which species dynamics can be assessed under a series of conservation threats, such as land use and climate change

An inventory describing the fluxes of the volatile organic compound (VOC), isoprene, and the class of VOCs, the monoterpenes, from the biosphere to the atmosphere has been constructed for Great Britain (GB). The controlling parameters were emission potentials from individual plant species, plant species distribution, biomass distribution, temperature, and light intensity. Species distribution and cover data from a national survey of vegetation in 1990 were used. A database of monthly biomass factors was compiled and a qualitative database of VOC emission potentials from vegetation species was updated to a quantitative form. This was used in conjunction with a taxonomic methodology to assign isoprene and monoterpene emission potentials to each plant species extant in GB. Hourly meteorological data for 1998 were calculated using a three-dimensional nonhydrostatic meteorological mesoscale model (MM5) and these were used to predict the isoprene and monoterpene fluxes in GB in 1998 on a spatial scale of 12 × 12 km and with an hourly temporal resolution. Estimates of annual biogenic isoprene and monoterpene fluxes were 8 and 83 kt, respectively, for the model year. Picea sitchensis (Sitka spruce) is the dominant emitting species in GB, emitting approximately 40% of the annual isoprene and monoterpene fluxes. The dominant emitting regions in GB are coniferous forests in Scotland (isoprene and monoterpenes) and a Populus spp. (poplar) rich area in eastern England (isoprene). Overall uncertainty in the estimates is a maximum of a factor of 4. A sensitivity analysis of the model was used to study the impact of changes in vegetation cover and climate on VOC emission.