Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

The Theory of Island Biogeography

Cengage Learning, 2000. Book Condition: New. Brand New, Unread Copy in Perfect Condition. A+ Customer Service! Summary:

Applied Nonparametric Statistics

This meta-analysis of land-cover transformations of the past 10–15 years in tropical forest-agriculture frontiers world-wide shows that swidden agriculture decreases in landscapes with access to local, national and international markets that encourage cattle production and cash cropping, including biofuels. Conservation policies and practices also accelerate changes in swidden by restricting forest clearing and encouraging commercial agriculture. However, swidden remains important in many frontier areas where farmers have unequal or insecure access to investment and market opportunities, or where multi-functionality of land uses has been preserved as a strategy to adapt to current ecological, economic and political circumstances. In some areas swidden remains important simply because intensification is not a viable choice, for example when population densities and/or food market demands are low. The transformation of swidden landscapes into more intensive land uses has generally increased household incomes, but has also led to negative effects on the social and human capital of local communities to varying degrees. From an environmental perspective, the transition from swidden to other land uses often contributes to permanent deforestation, loss of biodiversity, increased weed pressure, declines in soil fertility, and accelerated soil erosion. Our prognosis is that, despite the global trend towards land use intensification, in many areas swidden will remain part of rural landscapes as the safety component of diversified systems, particularly in response to risks and uncertainties associated with more intensive land use systems.

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Trends, drivers and impacts of changes in swidden cultivation in tropical forest-agriculture frontiers: A global assessment

Despite recent progress in understanding mechanisms of tree species coexistence in tropical forests, a simple explanation for the even more extensive diversity of insects feeding on these plants has been missing. We compared folivorous insects from temperate and tropical trees to test the hypothesis that herbivore species coexistence in more diverse communities could reflect narrow host specificity relative to less diverse communities. Temperate and tropical tree species of comparable phylogenetic distribution supported similar numbers of folivorous insect species, 29.0 ± 2.2 and 23.5 ± 1.8 per 100 square meters of foliage, respectively. Host specificity did not differ significantly between community samples, indicating that food resources are not more finely partitioned among folivorous insects in tropical than in temperate forests. These findings suggest that the latitudinal gradient in insect species richness could be a direct function of plant diversity, which increased sevenfold from our temperate to tropical study sites.

There So Many Species of Herbivorous Insects in Tropical Rainforests

A critical synthesis of remotely sensed optical image change detection techniques

Land use and deforestation in the highlands of Chiapas, Mexico

This study was conducted in the Chiapas Highlands, a tropical mountain region where traditional agricultural practices have resulted in a mosaic landscape of forest fragments embedded in a matrix of secondary vegetation and crop fields. The question addressed was how may woody species richness be affected by forest fragment attributes derived from traditional land-use patterns. Species inventories of total woody species, canopy and understorey trees, and shrubs were obtained in 22 forest fragments (≥5 ha). Multiple regression analyses were applied to examine the effects of size, matrix, isolation and shape of the forest fragments on richness of these species guilds. Fragment size was correlated with shape (r = 0.75) and isolation (r = −0.69), and isolation was correlated with shape (r = −0.75). Total species richness, and number of shrubs and understorey trees in fragments were related to isolation; moreover, additive effects of fragment shape were found for shrubs. The number of canopy species was not related to any fragment variable. Matrix did not help to explain species richness, possibly due to the landscape structure created by the traditional land-use patterns. In addition to size and isolation, we point out the need of considering shape and matrix as additional fragmentation attributes, along with social and economic factors, if we are ever going to be successful in our management and conservation actions.

Effect of forest fragmentation on the woody flora of the highlands of Chiapas, Mexico

The cloud forest of Mexico, a plant formation widely known in this country as mesophyllous montane forest (bosque mesofilo de montana), comprises a diverse array of plant associations that collectively occupy nearly 1% of the national territory. Because of its fragmented distribution at mid - and high elevations of the humid mountain ranges (mostly but not continuously between 1500 and 2500 m altitude), its complex biogeographic history, and its adjacency with many other vegetation types, Mexican cloud forests host at least 10% of the country's vascular plant flora, estimated at around 27 000 species. A recent appraisal showed that of a total of 762 tree species that thrive in these forests, at least 60% are in one of the various threat categories defined by the IUCN (23% Vulnerable, 27% Endangered, and 11% Critically Endangered). Current trends of population growth, land use/land cover change, and global climate change demand conservation and restoration actions to help revert their effects. The conventional conservation model consisting in the establishment of natural protected areas may be viable and still necessary in some areas to preserve the integrity of cloud forests as a whole. Nevertheless, novel restoration strategies are needed across most of its original range that are capable of reconciling the sustainable exploitation of these forests and the well-being of their inhabitants with the conservation of the extraordinary natural heritage that these forests signify for Mexico and the world.

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Mario González-Espinosa

Papers

Land use and deforestation in the highlands of Chiapas, Mexico

Effect of forest fragmentation on the woody flora of the highlands of Chiapas, Mexico

Los bosques de niebla de México: conservación y restauración de su componente arbóreo