Introduction

Mexico's geographical location, climatic diversity, topographic heterogeneity, and geological history, have fostered the establishment of one of the richest biological assemblages in the planet. Mexico harbours between 10 and 12% of the global diversity, making it one of the five richest countries in the world as to numbers of plant and amphibian species, the second as for reptile species and the third as for mammals (Espinosa et al., 2008). As for ecosystem diversity, Mexico is, along with Brazil, the most diverse country in Latin America (Dinerstein et al., 1995) and, worldwide, only India and Peru harbour a similarly high diversity (Rzedowski, 1998). In addition, Mexico is one of the major centers for plant domestication in the world, where at least 118 crop species, many of them of high nutritional value such as corn and beans (Sarukhán et al., 2008), have been developed. Thus, Mexico possesses an invaluable biodiversity wealth, in terms of ecosystems, species and genes.

Species and ecosystems provide a wide range of environmental goods and services: the variety of food items; wood for furniture, paper, and wood; natural fibers; active ingredients for pharmaceuticals; health food products; resins and dyes are just some examples (UNDP et al., 2000; Hanson et al., 2008; Ranganathan et al., 2008). In addition, ecosystems provide essential life-sustaining services, including water and air purification; waste decomposition and removal; climate regulation; soil fertility and biodiversity maintenance, among others (UNDP et al., 2000; Schuyt and Brander, 2004; Chivian, 2008). However, environmental degradation is threatening the permanence and continuity of these environmental goods and services.

Mexico has lost a significant percentage of the surface area originally covered by its natural ecosystems and, with them, several dozens of its plant and animal species, leaving many others at risk. Although Mexican biodiversity faces many threats, it is recognized that the conversion of natural ecosystems, the overexploitation of wild populations, environmental degradation and the introduction of alien species are the ones producing the major impacts (Arriaga et al., 1998; 2000, Challenger, 2009).

The long dismissal of environmental issues in development policies, the implementation of short-term policies to address economic and social problems, and the insufficient federal investment in the environmental sector, have directly or indirectly contributed to the deterioration of the country’s environment. Nowadays, there are many government initiatives aimed at the protection, sustainable management and recovery of the country’s biological wealth. The National System of Protected Natural Areas, the Payment for Environmental Services schemes, the various Programs for the Conservation and Recovery of Priority Species, the establishment of Management Units for the Conservation of Wildlife (UMA), and numerous regulatory, inspection and surveillance efforts are just some examples.

In this chapter, select indicators aimed to describe the state of Mexican biodiversity, and the importance of the pressures affecting it, are proposed. Indicators of the actions taken by the government to protect and, where possible, reverse the deterioration of ecosystems and the decline of population sizes of some species, are also included. Given the character, width and dynamic character of the issue, only two levels of biodiversity are hereby addressed: ecosystems and species. Although the genetic diversity of Mexican species is also significant (Piñero et al., 2008), information available is insufficient to define a set of indicators that adequately describe the pressures, state and responses pertaining to this other level of biodiversity.

Biodiversity indicators are presented in separate sections devoted to terrestrial, marine and freshwater systems, largely due to the differences between those environments, and the pressures affecting them. In addition, special sections devoted to particular biological communities or species groups which, because of their relevance or specific problems, deserve specific attention, are also included. Finally, as some of the indicators of social and economic activities dealt with in other sections of this report are also relevant for biodiversity, they are also included here. Although this would complement and enrich the overview of the subject, in order to not present duplicate information, the interested reader is referred to the proper section in the report where those other subjects are developed at length.

References

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