Adequacy of Current Measures to Protect Biodiversity

Although there are many stresses on the region's biodiversity, we have witnessed more areas decreed as protected (as international, national or state biosphere reserves) in the last decade than any other decade in the history of the Sonoran bioregion (Figure 10). The establishment of the biosphere reserves of the Viscaino Desert, of the Pinacate and Gran Desierto, and of the Colorado River Delta and Upper Gulf, have been major conservation achievements in northern Mexico. The combined area of the Pinacate Biosphere Reserve, Organ Pipe National Monument and the Barry M. Goldwater Air Force Range is the largest contiguous, essentially unfragmented area under protective management in the lower 48 states or Mexico. In addition, there are more resource managers trained in conservation biology working on both sides of the border than there were a decade ago, and the distribution of field scientists between nations is more equitable than ever before. However, these conservation biologists hardly have had time since the most recent biosphere reserve decrees to assess the representativeness of current protected areas, and to set priorities for additional needed reserves.

The scientists responding to our surveys mentioned a great variety of land and sea reserves already established in the region which have, among other objectives, the goal of protecting biodiversity.

Today, about 1,500,000 hectares -- roughly 8% of the land surface of the state of Sonora -- is under some protection. This figure does not consider reserves lost to city development and marine areas. So far, on the two biosphere reserves, the area of Sierra de los Ajos and the protected area near Alamos are operating formally as reserves, with permanent staffing at their headquarters. All other reserves do not have any (real) protection, but that given by the edicts and their [geographic] isolation." (Btarquez and Martínez-Yrízar, 1997)

The Mexican reserves with at least some value to biodiversity conservation in the Sonoran bioregion are listed in Table 10a and the U.S. protected areas are in Table 10b.

Additional areas of the Sonoran Desert and adjacent Gulf of California have been proposed for protection by the Comision Nacional para el Conocimiento y Uso de la Biodiversidad (CONABIO), the Centro Ecologico de Sonora, other NGOs, and academic institutions. These areas (Table 11) occur within coastal thornscrub, foothills thornscrub, and riparian areas. They harbor large herds of bighorn sheep (Sierra El Viejo), and the last natural population of Masked Bobwhite Quail (Rancho El Carrizo) (Búrquez and Martínez-Yrízar 1997). An effort to create a Biosphere Reserve for all of the San Pedro Martir range in Baja California Norte has also been advanced.

Of course, there are many other areas which are still underprotected, either because they fall outside of conservation-oriented reserves, or because they are reserves "on paper" only. Table 12 summarizes responses to questions regarding the adequacy of formally protected areas and their management to protect biodiversity.

The mere fact that a protected area is established and "managed" does not necessarily mean that all activities are halted which potentially deplete biodiversity. When asked if protected area managers still allow such activities, twenty-five answered yes, nine answered no, seventeen answered that such harmful activities now occur less than before, and five had no response. The reality that many of northern Mexico's protected areas are less than ten years old would suggest that not all activities harmful to biodiversity ceased on the day(s) that these areas were formally decreed. However, it is a hopeful sign that already, over one quarter of the respondents see fewer harmful activities occurring within protected areas today than "before" -- before, in this case, meaning either before their decree, or for early-established parks and wildlife refuges, before 1975.

In a similar vein, we asked field scientists which threats to biodiversity are beginning to be adequately addressed. In their analysis of trends in different subregions, seven of the scientists felt that grazing was finally being addressed sufficiently in discussions between resource managers, ranchers and scientists; five felt that the impacts of ecotourism (eg., whale watching) and outdoor recreation were being sufficiently dealt with at the local level; and two felt that urban growth and residential land uses were being discussed fairly in certain localities. However, twenty-two of the scientists felt that no threat is being adequately addressed anywhere in the Sonoran biome where they have worked. Another scientist lamented that the current species-by-species approach to biodiversity conservation is providing only stop-gap solutions, some of which may be counterproductive over the long run.

We requested that scientists alert us to threats that have become more severe in each subregion and which species are most vulnerable to these and other threats. We also asked them to name areas undergoing rapid environmental change that could lead to further declines in diversity. Finally, we requested the nomination of areas for formal protection, including priority areas (Table 13). Table 13 is certainly not complete as it is a function of the collective knowledge of the scientists that responded to the survey. For instance, the conservation priorities cited by individual scientists should be revisted in light of the whole list of areas meriting protection. It is however, a good foundation for further development of a conservation portfolio and listing the principle threats that need to be addressed for successful biodiversity conservation.

While we need to attain protection of the priority areas of high biodiversity listed in this report and other sources, we must remember the critical role that the large expanses of BLM and Native American land in the U.S. can play in the maintenance and restoration of landscape connectivity. For example, with 42% of Arizona's land under federal control and 27% under Native American control, successful landscape scale conservation must seek effective, cooperative means to improve conservation measures on these lands. While the federal land ownership situation in northern Mexico may be different, the very presence of U.S. federal lands along the border could provide some leverage of binational support for biodiversity protection.

"La conservaci6n de la riqueza floristica exclusiva de la peninsula de Baja California no podra realizarse con el numero actual de areas protegidas. La planificaci6n de futuras areas protegidas en la peninsula debera tomar en consideraci6n los patrones de distribuci6n de estas especies end6micas, especialmente si se quiere preservar para las futuras generaci6nes esta riqueza en endemismos.°

"The conservation of the floristic richness found exclusively on the Baja California peninsula cannot be accomplished with the present number of protected areas. Planning of future protected areas on the peninsula ought to take into account the patterns of distribution of these endemics, especially if one wishes to preserve for future generations this rich center of endemism."

- Jose Luis villasenor and Thomas S. Elias
Consenracion de Plantas en Peligro de Extincion: Diferentes Enfoques (1995)