The problem of fragmentation

Habitat fragmentation is widely recognized as a major threat to biodiversity conservation. In mountains, fragmentation affects single-ecosystem types as well as continuity between habitats or ecosystems along altitude gradients. Fragmentation implies habitat and species loss, change in the composition of fauna, changes in ecological processes, and hence less biodiversity.

The Sierra de Portuguesa is the northeast portion of the Venezuelan Andes, located between 9°00′ and 10°00′N and 69°00′ and 70°00′W. Five major rivers of regional importance have their sources there. Evergreen forests and cloud forests predominate above 1600–1800 m along the sierra ridge. Before the 15th century European colonization, indigenous peoples probably practiced extensive and scattered shifting cultivation. With the decline of the 19th century coffee economy and the arrival of new European immigrants, pressure on forests increased, leading to new forest-free agricultural techniques, including traditional shifting cultivation.

Today the rural population consists mostly of small farmers growing coffee, tomatoes, or potatoes and practicing mixed cultivation. Coffee probably can no longer be considered ecologically sound because more productive new varieties have been introduced that require direct sunlight instead of shade. Despite this, industrial fertilizers are rarely used. The recent collapse of coffee prices might force a shift to other open-cultivation systems, although higher prices for organic coffee could be an incentive that prevents this. Dairy cattle are also significant. This pattern leaves cloud forests along the sierra ridge, strips of forest along the natural drainage system, and some forest pockets on humid and steep slopes largely untouched, resulting in a fragmented landscape (Figure 1). Small towns and villages, which provide services for farmers, are located strategically on midslopes and terraces, serving as nodes for dirt roads that provide access to the interior of the sierra.

In 1962, the 29,580-ha Yacambú National Park was established on a significant portion of public land in the Yacambú River watershed to ensure water quality and supply for the future Yacambú Dam, which was essential to an ambitious hydraulic system on adjacent semiarid lowlands. A second National Park, Terepaima, 18,650 ha in size, was designated just 21 km to the northeast in 1976 for watershed protection and conservation of biodiversity. Finally, in 1993, 7 km south of Yacambú, the 12,200-ha Guache National Park was established to protect biodiversity and another watershed important to foothill towns. Is it possible to link three parks so close together, with forests fragmented along the sierra? And could the long-term survival of bears be enhanced?

What is the role of bears in all this? Corridors are generally thought of as benefiting animals. The Sierra de Portuguesa is an Andean bear (Tremarctos ornatus) habitat, and bears are still present here (Figure 2). But a fragmented habitat is bad news for their survival, even more so when there is significant pressure from hunting. No field-confirmed data are available, but estimates suggest that there is room for about 16 bears within the parks—about 5 in each park. This is a very small number, and if these isolated populations cannot interact, the situation is even worse. Any means of interconnecting these populations will increase the bears' long-term survival chances.

Alternatives for interconnection

Landsat TM images showing vegetal cover in 2000 were used to map vegetation in the sierra. A geographic information system (GIS) was very useful for handling spatial information—elevation, vegetation, soil types, etc—and selecting options. The results showed that a long, continuous narrow forest strip still existed along the sierra ridge between the Terepaima and Yacambú Parks, about 11,400 ha in size, mostly above 1400 m (Figure 3). The predominant land use around this forest strip is small-size coffee groves. This confirmed that a corridor was feasible and that deforestation had not been severe in the last 10 years. It also showed a lack of forest continuity between the Yacambú and Guache Parks. If we hope to maintain or restore forest continuity, the options are to keep forest as it is between Yacambú and Terepaima (Corridor A) and to restore forest between Yacambú and Guache (Corridor B). We decided to work first on Corridor A because we estimate that this is more cost-effective. Corridor B involves restoration techniques applied on private or occupied land, which probably requires a different approach. Corridor implementation involves formal legal protection and agreements among local populations on practices that promote sustainable use of natural resources. Formally protected areas may be criticized by those who argue that there are already too many protected areas that impede rural development. On the other hand, it can be argued that sustainable practices take too long to render results when forests are cut and fragmentation occurs.

Building consensus

Our strategy for reaching consensus was to present only facts and alternatives and discuss the positive and negative consequences of such alternatives, or any other new position, freely and openly, without bias. Discussion was promoted among those called upon to give political approval to the concept and those directly affected by the decision. Among the first group were the representatives of the federal Parks Service; the Environment Ministry; and state, local, and municipal governments. The second group consisted of farmers who live within or around the corridor areas, organized in associations, and different interested regional and local nongovernmental organizations concerned with the environment and social development, as well as water management concessionaires and universities. Discussions were held in 6 general workshops, one of which focused only on technical aspects with Ministry of Environment personnel, with all the above groups in attendance (Figure 4). An additional 15 focal meetings were held with local farmer leaders.

To our surprise there was consensus about the urgent need to stop deforestation on the upper watersheds. Most enthusiastic were the small farmers living on the edge of the forest, who feared a lack of water for their groves, as experienced by those who live down-slope and in the foothills. Some actors were particularly worried about loss of biodiversity, but most were worried about the disappearance of water sources. Another surprise was the consensus on designating the corridor as an expansion of Terepaima National Park. The farmers' leaders proposed this idea themselves because they believed that there must be an authority with the legal power and local presence to enforce the law.

It is interesting to note the favorable attitude farmers have toward any initiative regarding conservation of forest and water sources. They are rarely contacted by groups promoting such ideas, which they consider vital, along with medical assistance, education, maintenance of rural roads, and agricultural extension.

As a consequence of the workshops and meetings, more than 400 farmers have already signed a letter asking government agencies to take steps to designate the corridor forest as part of the Terepaima National Park, and the number is increasing. This is also good news for the Andean bear. Hunting is common among local people, but there is great concern about the fate of bears, even among farmers; farmers' livelihoods do not depend on hunting. The Andean bear is the symbol of Sanare, the largest town of the sierra. Farmers' associations are enthusiastic about ecotourism as a new activity because bears are a perfect tourist attraction, even though it is difficult to observe them in their habitat.

Future steps

Corridor A is not likely to become part of Terepaima National Park soon. The national political agenda in Venezuela is too focused on broader problems, such as the legitimacy of the government. Nevertheless, the consensus achieved is the basis for a “gentlemen's agreement” among all actors on keeping the corridor unaltered until a high-level political decision is made.

A preliminary-impact assessment of Corridor B (not visible on Figure 3, south of Yacambú National Park) was conducted by geographer Mirady Sebastiani of Simon Bolivar University. She recommends conducting a more detailed analysis of the expectations of the rural population to determine exactly where and how to restore vegetation between the Guache and Yacambú Parks.

What has been achieved until now, even for Corridor A, is only a first step toward corridor implementation. The next step is to continue promoting the concept at all political levels and among the rural community. But examples of sustainable use are urgently needed. For instance, some farmers have started producing mountain mahogany saplings (Cedrela sp.) for commercial purposes, which shows long-term commercial vision. Expectations for ecotourism are also growing. Extension is urgently needed to promote production of quality organic coffee because coffee production is the predominant land use. Farmers do not have mechanisms for promoting their products in such quality markets. Fostering approaches and initiatives such as these will be a key issue in the future.