Habitat quality and metapopulation e¡ects are the main hypotheses that currently explain the disproportionate decline of insects in cultivated Holarctic landscapes. The former assumes a degradation in habitat quality for insects within surviving ecosystems, the latter that too few, small or isolated islands of ecosystem remain in landscapes for populations to persist. These hypotheses are often treated as alternatives, and this can lead to serious con£ict in the interpretations of conservationists. We present the ¢rst empirical demonstration that habitat quality and site isolation are both important determinants of where populations persist in modern landscapes. We described the precise habitat requirements of Melitaea cinxia, Polyommatus bellargus and Thymelicus acteon, and quanti¢ed the variation in carrying capacity within each butter£y's niche. We then made detailed surveys to compare the distribution and density of every population of each species with the size, distance apart and quality of their speci¢c habitats in all their potential habitat patches in three UK landscapes. In each case, within-site variation in habitat quality explained which patches supported a species' population two to three times better than site isolation. Site area and occupancy were not correlated in any species. Instead of representing alternative paradigms, habitat quality and spatial e¡ects operate at di¡erent hierarchical levels within the same process: habitat quality is the missing third parameter in metapopulation dynamics, contributing more to species persistence, on the basis of these results, than site area or isolation. A reorientation in conservation priorities is recommended.

The benefits of protected areas (PAs) for biodiversity have been questioned in the context of climate change because PAs are static, whereas the distributions of species are dynamic. Current PAs may, however, continue to be important if they provide suitable locations for species to colonize at their leading-edge range boundaries, thereby enabling spread into new regions. Here, we present an empirical assessment of the role of PAs as targets for colonization during recent range expansions. Records from intensive surveys revealed that seven bird and butterfly species have colonized PAs 4.2 (median) times more frequently than expected from the availability of PAs in the landscapes colonized. Records of an additional 256 invertebrate species with less-intensive surveys supported these findings and showed that 98% of species are disproportionately associated with PAs in newly colonized parts of their ranges. Although colonizing species favor PAs in general, species vary greatly in their reliance on PAs, reflecting differences in the dependence of individual species on particular habitats and other conditions that are available only in PAs. These findings highlight the importance of current PAs for facilitating range expansions and show that a small subset of the landscape receives a high proportion of colonizations by range-expanding species.conservation | climate change adaptation | nature reserves M ore than 10% of the Earth's land surface has already been designated as protected area (PA) (1, 2), and there are calls to expand protection to 17% of the land (3, 4). However, the importance of a PA approach to conservation is open to question in the context of anthropogenic climate change and other environmental drivers that are causing species to shift their distributions. Terrestrial species' distributions are shifting to higher latitudes and elevations (5-7), many species are at increased risk of extinction (8,9), and the composition of biological communities is changing (10, 11). These observations, combined with predicted future changes to the composition of biological communities inside PAs (12-16), call into question (i) the long-term protection provided to species by PAs, because species may shift out of the sites where they were previously considered to be protected, and (ii) the legislative basis for protection in situations where legal PA designation stems from the occurrences of particular species or biological communities (17, 18) that may not remain within the PAs in the future. PAs have, on occasion, been downgraded or dedesignated in the face of competing demands (19), and there are suggestions that a PA approach could be outmoded (20) or that underperforming PAs should be replaced (21).However, the overall risk to a species from climate change (and other large-scale drivers of distribution change) depends on the balance between losses of populations within the former range, on the one hand, and gains associated with the colonization of new regions where the climate or other conditions improve (8, 9)....

We review changes in the status of butterflies in Europe, focusing on long-running population data available for the United Kingdom, the Netherlands, and Belgium, based on standardized monitoring transects. In the United Kingdom, 8% of resident species have become extinct, and since 1976 overall numbers declined by around 50%. In the Netherlands, 20% of species have become extinct, and since 1990 overall numbers in the country declined by 50%. Distribution trends showed that butterfly distributions began decreasing long ago, and between 1890 and 1940, distributions declined by 80%. In Flanders (Belgium), 20 butterflies have become extinct (29%), and between 1992 and 2007 overall numbers declined by around 30%. A European Grassland Butterfly Indicator from 16 European countries shows there has been a 39% decline of grassland butterflies since 1990. The 2010 Red List of European butterflies listed 38 of the 482 European species (8%) as threatened and 44 species (10%) as near threatened (note that 47 species were not assessed). A country level analysis indicates that the average Red List rating is highest in central and mid-Western Europe and lowest in the far north of Europe and around the Mediterranean. The causes of the decline of butterflies are thought to be similar in most countries, mainly habitat loss and degradation and chemical pollution. Climate change is allowing many species to spread northward while bringing new threats to susceptible species. We describe examples of possible conservation solutions and a summary of policy changes needed to conserve butterflies and other insects.

Summary 1.Many ecological studies and applications involve measuring the height of grassland swards. An evaluation was made of the practicality, accuracy and comparability of using the sward stick, drop disc and direct methods of measurement. Each method proved to be appropriate for measuring swards that contain a wide range of heights, each was quick to perform, and recorder effects were negligible. Yet each had strengths and weaknesses. 2. The sward stick gave the most variable results: it was considered the best method for recording the architecture of the sward surface, and hence invertebrate niches, but was poor for measuring short turf. The drop disc was the worst method for recording microheterogeneity in sward architecture and was completely unsuitable for measuring variation in short turf. But in medium-tall swards, it was considered to be the best method for measuring productivity, vertebrate herbivory and for large-scale monitoring of land managed for conservation and under agri-environment schemes. The direct method gave the most consistent and accurate results compared with an independent parameter, soil temperature. It was the only method suitable for measuring variation in short turf. 3. A serious problem exists when research results, recommendations and assays involve measurements made by more than one method. The sward stick consistently gave higher absolute values than either of the other methods and, apart from in short turf (for which it is unsuitable), the drop disc gave values that were 73% and up to 40% lower, respectively, than those obtained using the sward stick and direct methods. This can lead to major misapplications of ecological results and recommendations in conservation and agri-environmental projects.

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