Energy and nutrients

This chapter deals with the ecology of Tropical East Asia from the perspective of water, energy, and matter flows through ecosystems, particularly forests. Data from the network of eddy flux covariance towers is revealing general patterns in gross primary production, ecosystem respiration, and net ecosystem production, and exchange. There is also new information on the patterns of net primary production and biomass within the region. In contrast, our understanding of the role of soil nutrients in tropical forest ecology still relies mostly on work done in the Neotropics, with just enough data from Asia to suggest that the major patterns may be pantropical. Nitrogen and phosphorus have received most attention regionally, followed by calcium, potassium, and magnesium, and there has been very little study of the role of micronutrients and potentially toxic concentrations of aluminium, manganese, and hydrogen ions. Animal nutrition has also been neglected.

Threats to terrestrial biodiversity

More than a billion people inhabit Tropical East Asia today and negative impacts on ecosystems and wild species are pervasive. Historically, the ultimate driver has been human population growth, but while this is now slowing, there is no prospect of an early reduction in human impacts. Poverty, corruption, weak governance, and globalization are additional underlying drivers. The major proximal threats and their consequences—deforestation, habitat fragmentation, mining, urbanization and infrastructure development, logging and the collection of non-timber forest products, hunting and the wildlife trade, fires, invasive species, emerging infectious diseases, air pollution and nutrient enrichment, and anthropogenic climate change—are described in turn in this chapter. Finally, the problems of assessing and predicting extinctions are discussed.

The ecology of plants: from seed to seed

This chapter deals with the ecology of Tropical East Asia from a plant perspective. The life cycle of forest trees is covered in detail, including their vegetative and reproductive phenology, pollination, seed dispersal, seed predation, and the seedling, sapling, and adult stages. Other life forms, including lianas, ground herbs, epiphytes, hemi-epiphytes, and parasites are considered in less detail. Recent advances in plant community ecology are discussed, including the mechanisms responsible for the maintenance of species diversity in tropical forests (niche differentiation, growth–survival trade-offs, conspecific negative density-dependent mortality, neutral theory), and the influence of functional traits and phylogeny on community assembly. Forest succession is discussed in a regional context.

The ecology of animals

Most biomass consists of plants but most non-microbial species are animals, and these animals play a great diversity of roles in tropical ecosystems. This chapter therefore deals with the ecology of Tropical East Asia from an animal perspective, focusing on the diets of both vertebrates and invertebrates, and the role of food quality and phenology in diet choice. Specialist and generalist feeders are distinguished and contrasted. The major diet groups covered include the herbivores (including leaf, shoot, root, bark, and wood feeders, as well as sap suckers and honeydew feeding ants), flower visitors, frugivores, granivores, detritivores, carnivores (including specialists on invertebrates and vertebrates), blood feeders, parasites and parasitoids, omnivores, scavengers, and coprophages.

Physical geography

This chapter covers the physical geography of Tropical East Asia from a biological perspective. The first section, on weather and climate, focuses on temperature, rainfall, and their seasonality, and also considers the impacts of interannual variation in rainfall. The next section deals with fire and its relationship with climate. The following section on soils concentrates on the soil classifications used within the region. The major vegetation types of the region are then described in detail, including the major natural and anthropogenic types, from tropical rainforests to paddy fields to urban areas.

Environmental history

This chapter covers the environmental history of Tropical East Asia, starting with its assembly from Gondwanan fragments during the Mesozoic. Changes in sea level, climate, and vegetation are covered in increasing detail from the Eocene to the present day, and the influence of volcanic eruptions and other natural catastrophes is discussed. The history of human occupation is outlined, from the appearance of Homo erectus more than a million years ago, through the arrival of modern humans in the region 80,000–50,000 years ago, to the spread of agriculture and the development of urban settlements. Human impacts on natural ecosystems are considered throughout the period of occupation, culminating in the concept of the human-dominated Anthropocene.

Conservation in the Anthropocene

This chapter considers options for conserving the biodiversity of Tropical East Asia in the face of the pervasive threats described in previous chapters. Sources of funding are first considered, including domestic governments, foreign aid, non-governmental organizations, businesses, payments for ecosystem services, REDD+, biodiversity offsets, tourism, and eco-certification. The next section discusses the use of surrogates in conservation planning, methods of prioritizing species, and various approaches to prioritizing areas and ecosystems. The establishment of new protected areas is dealt with along with alternative models for protection. This is followed by the options for reducing unsustainable exploitation of timber, wildlife, and other forest products, controlling fires, managing invasive species, and minimizing the magnitude and impacts of climate change. The potential for restoring forests and reintroducing species is then discussed. The chapter ends with sections on education and related issues, and a discussion of possible ways forward for biodiversity conservation in Tropical East Asia.

Biogeography

This chapter deals with the geographical distribution of plants and animals within the region. Tropical East Asia is defined as the eastern half of the Oriental Region and the other biogeographical regions are briefly described. The transitions between Tropical East Asia and the adjacent Australian and Palearctic Regions are described and discussed, as well as the less clearly defined transition with the rest of India. Patterns of diversity within Tropical East Asia are considered and four major subregions (Wallacea, the Philippines, Sundaland, and Indochina) are recognized. The remainder of the chapter deals with the biogeography of the numerous islands in the region, including the islands on the Sunda Shelf, Hainan and Taiwan, the Ryukyu and Ogasawara Islands of Japan, the Andaman and Nicobar Islands of India, the Mentawai Islands and others off the west coast of Sumatra, Krakatau, the Philippines, Sulawesi, and the islands of Wallacea.