Becoming Europe: Southeast Asia in the Anthropocene

Abstract

When I visited the Southeast Asian tropics as an undergraduate in 1973 it seemed as different from my European home as anywhere on Earth could be. The forest was already in retreat, but large contiguous tracts remained virtually intact. Fast-forward 40 years, however, and more than half of the original forest cover of Southeast Asia has gone, more than half of what remains has been logged or otherwise degraded, and the majority, logged or unlogged, has lost most or all of its large vertebrate fauna to hunting (Corlett, 2009). The non-forest areas are increasingly dominated by plantation monocultures, or by urban areas and their associated infrastructure, and most of the native biota is confined to areas with more or less intact forest cover, while a few native species and an increasing number of exotics have massively expanded their populations. Air pollution and nitrogen deposition are pervasive, but unstudied, problems and the impacts of climate change are becoming apparent. The crop monocultures are trees rather than cereals, but in other ways the region is fast becoming a tropical version of Europe. The densely-populated Philippines and Vietnam have similar human population densities to Belgium and the UK, and relatively sparsely populated Laos to Sweden (Table 1). At the regional scale, Southeast Asia has a somewhat higher mean population density than the European Union (EU) and, since it is still less urbanized, rural population densities are even higher. The per-capita GDPs of the richer countries in Southeast Asia (excluding tiny Singapore and oil-rich Brunei) already overlap with the poorer countries in the EU, and are rising more rapidly. Other statistics are also converging, including infant mortality, life expectancy, and total fertility rates (Table 1). Both regions were once largely forested and their total remaining forest cover is similar today (44% for TEA, 37% for the EU), as is the variation among countries, although nowhere in Southeast Asia has as little forest left as the Netherlands, Ireland and the UK. Both regions have suffered few known extinctions in historical times (iucnredlist.org). Despite these similarities, Europe is considered a relative success story in conservation terms, while Southeast Asia is widely seen as an on-going biodiversity crisis (Sodhi et al., 2004, 2010; Wilcove et al., 2013). There are good reasons for this. First, there is much more biodiversity at stake in Southeast Asia, which, in well-studied groups, supports 15–25% of global terrestrial species (Corlett, 2009). Europe, by contrast, has considerably fewer species (, 5% of the global total) in a similar total land area. Secondly, species in tropical forests are likely to be more vulnerable to extinction, both because high biodiversity means small population sizes, but also because of the extreme contrast between the environment of closed-canopy tropical forests and the anthropogenic habitats that replace them. Few non-coastal native species can survive outside forest in Southeast Asia, while many have adapted to human-dominated landscapes in Europe. Thirdly, the ecological transformation of Southeast Asia has been extremely rapid and the persistence of many species only as tiny, isolated populations implies large extinction debts. Moreover, while European landscapes are now changing relatively slowly, there is no sign of a slowdown in Southeast Asia, implying a future with less forest and fewer species. Finally, Europe is the ecologically best-known region of the planet, while Southeast Asia is still among the least, to the detriment of conservation planning and implementation. This new tropical landscape calls for a new tropical ecology: one that does not require large tracts of pristine forest, or ‘fragments’ of this forest isolated in a uniformly hostile matrix. An ecology of patches of irregular size, shape, history and composition, of novel ecosystems that combine species which have not previous met, of chronic disturbances and ubiquitous edge effects, of heterogeneity and change. European ecologists have always worked in such landscapes, since they have no others, but the foundations of this new ‘tropical countryside ecology’ have been laid in the most densely populated areas of the Neotropics, Domain Editor-in-Chief Donald R. Zak, University of Michigan