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In many cases, the designation of Protected Areas (PAs) is not based on biological information, particularly in tropical regions where such information is generally lacking. Thus it is unclear whether tropical PAs are well-placed for conserving biodiversity currently, or under future climate change. We used reserve-design software (‘Zonation’) to investigate current and future conservation value of PAs of Thailand (N = 187 PAs, covering ∼20% of Thailand) in relation to forest-cover and butterfly diversity. Currently, PAs are about 2 °C cooler than non-PAs because PAs tend to occur at higher elevation (66% of land above 1000 m is protected compared with only 6% below 250 m). Temperature is predicted to increase in Thailand in future, but PAs are predicted to remain ∼2 °C cooler than non-PAs in future. We obtained modelled distribution data for 161 butterfly species (∼12% of national butterfly fauna), and used Zonation to rank areas (∼1 km2 grid resolution) based on species richness, complementarity, and forest cover. The conservation value of PAs was approximately twice that of non-PA areas, although many highly-ranked areas are not currently protected. The species richness of PAs was projected to decline by ∼30% in future, but the relative conservation rankings of individual PAs were projected to change very little. The preponderance of PAs in montane regions makes them well-placed to support forest species shifting from areas at lower elevation that become climatically unsuitable in future. By contrast, the conservation value of low-elevation PAs may decline in future if climate conditions become unsuitable for species.

Southeast Asia experiences one of the highest rates of deforestation in the tropics due to agricultural expansion, logging, habitat fragmentation and urbanization, which are expected to result in species declines and extinctions. In particular, growing global demands for food, biofuel and other commodities are driving the rapid expansion of oil palm and paper-and-pulp industries at the expense of lowland dipterocarp forests, further jeopardizing Southeast Asian forest biotas. We synthesize recent findings on the effects of land-use changes on plants, invertebrates, vertebrates and ecosystem functioning/services in Southeast Asia. We find that species richness and abundance/density of forest-dependent taxa generally declined in disturbed compared to mature forests. Species with restricted ranges and those with habitat and foraging specialization were particularly vulnerable. Forest loss also disrupted vital ecosystem services (e.g. crop pollination). Long-term studies are needed to understand biotic sustainability in regenerating and degraded forests, particularly in the context of the synergistic or additive effects of multiple agents of biodiversity loss (e.g. invasive species and climate change). The preservation of large tracts of mature forests should remain the principal conservation strategy in the tropics. In addition, reforestation and reintroductions of native species, as well as improved connectivity among forest patches could enhance the conservation value of forest remnants in human-dominated landscapes.

Commercial selective logging is a major cause of habitat disturbance in Southeast Asian rainforests, yet despite much research there is little consensus on impacts of disturbance on biodiversity. There is also little consensus on the most appropriate methods for sampling tropical species, making it difficult to draw general conclusions from published studies. For example, many studies have used butterflies to assess impacts of selective logging but sampling has usually been conducted at ground level and the canopy fauna has often been ignored. In this study, we investigate the importance of sampling in the canopy by using fruit-baited traps to investigate impacts of selective logging on Nymphalid butterflies in primary forest and forest selectively logged 15 years previously in Sabah (Malaysian Borneo). Analysing combined data from canopy (≈25 m above ground level) and ground-level traps showed significantly lower diversity in selectively logged forest. However, this difference was not observed when data from only ground traps were analysed. Primary forest supported a butterfly assemblage comprising species with more restricted geographical ranges, and thus higher conservation value, compared with selectively logged forest. This result was observed regardless of whether or not canopy data were included in this analysis. We conclude that sampling in the canopy is critical when producing species inventories, but of little importance when determining the impacts of selective logging on restricted-range species.

In modern landscapes, many populations of rare species are restricted to fragments of formerly extensive habitat. However, the potential for evolutionary changes in dispersal ability to occur within these fragmented populations has received little attention. We examined morphological traits associated with flight and reproduction in fragmented populations of the silver-spotted skipper butterfly, Hesperia comma . Investment in flight was measured as relative wing area and thorax mass, and investment in reproduction as relative abdomen mass. All measurements were made on individuals reared in a common environment. In the UK, Hesperia comma was once fairly widely distributed in southern and eastern England, but retracted to its smallest UK distribution in the 1970s and 1980s. It then partially re-expanded in the North and South Downs in S.E. England. We first compared traits from colonised and refuge sites 2.9–4.5 km apart, and found no differences in relative investment in flight or reproduction. There were, however, significant differences in both relative thorax and abdomen mass between regions >40 km apart. Populations with the highest relative investment in the thorax occurred in a region where population expansion has been most rapid. These results, in combination with other studies linking butterfly morphology to patch area and/or isolation, suggest that evolutionary responses to habitat fragmentation could be widespread. ©