This book provides complete, comprehensive, and broad subject-based reviews for students, teachers, researchers, policymakers, conservationists, and NGOs interested in the biodiversity and conservation of woody plants. Forests cover approximately 31 percent of the world’s total landmass; 93 percent is natural forest and only 7 percent consists of planted trees. Forest decline is progressing at an alarming rate worldwide. In addition to human activities (logging, deforestation, and exploiting forest lands for agriculture and industrial use), a number of other factors – including pests and diseases, drought, soil acidity, radiation, and ozone – are cumulatively contributing to global forest decline. The present situation forces us to focus on forest conservation strategies for the present and future. Gene conservation and maintaining genetic diversity in forest ecosystems are crucial to the preservation of forest genetic resources. This calls for integrated action to implement both the in situ (on site) preservation of forest stands and ex situ (distant from the original site) strategies for the conservation of woody plants’ genetic resources. Selected priority areas include: 1) assessing patterns of genetic diversity and threats, 2) understanding the biological processes regulating genetic diversity, 3) assessing the impact of human activities and climate change on genetic diversity, and 5) finding methods for prioritizing species and populations for the conservation of forest trees genetic resources. All chapters were written by leading scientists in their respective fields, which include: woody plant diversity, ecology and evolution; assessment of genetic diversity in forest tree populations; conservation planning under climate change; and in situ and ex situ strategies, including biotechnological approaches, for the conservation of woody plants genetic resources.

Trees and other woody plants, such as shrubs and lianas, form the principal components in forests and many other ecosystems on our planet. Being among the largest and longest-living organisms, they support an immense share of the Earth's terrestrial biodiversity, providing food and habitats for innumerable microorganisms, epiphytes, invertebrate, and vertebrate species. Woody species are perfect study objects, giving us a link between the past, present, and future. However, the future of many trees and shrubs is uncertain. Ten of thousands of species are threatened by overharvesting, non-native pests and diseases, changes in accelerated land use, and climate warming. Many aspects of their biology, ecology, and biogeography are still unexplored or insufficiently understood. These knowledge shortfalls, concerning their genetic diversity, for example, significantly hinder the development of protection strategies and the elaboration of efficient action plans. This book, dedicated to this very diverse group of plants, aims to encourage ongoing research and conservation efforts worldwide. In nine chapters, the most up to date research and case studies bring the reader to the most fascinating regions of our planet: from Madagascar and Mexico, via China and Japan, to the Hyrcanian Forest of Iran.

Forests and trees enhance and protect landscapes, ecosystems and production systems. They provide goods and services which are essential to the survival and well-being of all humanity. Forest genetic resources -- the heritable materials maintained within and among tree and other woody plant species that are of actual or potential economic, environmental, scientific or societal value -- are essential for the continued productivity, services, adaptation and evolutionary processes of forests and trees.

Tropical climates, which occur between 23°30'N and S latitude (Jacob 1988), encompass a wide variety of plant communities (Hartshorn 1983, 1988), many of which are diverse in their woody floras. Within this geographic region, temperature and the amount and seasonality of rainfall define habitat types (UNESCO 1978). The F AO has estimated that there 1 are about 19 million km of potentially forested area in the global tropics, of which 58% were estimated to still be in closed forest in the mid-1970s (Sommers 1976; UNESCO 1978). Of this potentially forested region, 42% is categorized as dry forest lifezone, 33% is tropical moist forest, and 25% is wet or rain forest (Lugo 1988). The species diversity of these tropical habitats is very high. Raven (1976, in Mooney 1988) estimated that 65% of the 250,000 or more plant species of the earth are found in tropical regions. Of this floristic assemblage, a large fraction are woody species. In the well-collected tropical moist forest of Barro Colorado Island, Panama, 39. 7% (481 of 1212 species) of the native phanerogams are woody, arborescent species (Croat 1978). Another 21. 9% are woody vines and lianas. Southeast Asian Dipterocarp forests may contain 120-200 species of trees per hectare (Whitmore 1984), and recent surveys in upper Amazonia re corded from 89 to 283 woody species ~ 10 cm dbh per hectare (Gentry 1988). Tropical communities thus represent a global woody flora of significant scope.

Original studies address key aspects of the conservation and biodiversity of plants. Articles are all peer-reviewed primary research papers, contributed by leading biodiversity researchers from around the world. Collectively, these articles provide a snapshot of the major issues and activities in global plant conservation. Many of the articles can serve as excellent case studies for courses in ecology, restoration, biodiversity, and conservation.