Sixty-Seven Years of Land-Use Change in Southern Costa Rica

Background

Habitat loss and fragmentation of forests are among the biggest threats to biodiversity and associated ecosystem services in tropical landscapes. This paper uses the vicinity of the Las Cruces Biological Station in southern Costa Rica as a regional case study to comment on seven decades of land-use change in one of the most intensively studied sites in the Neotropics.

Research goals & methods

Though the premontane wet forest was largely intact in 1947, a wave of immigration in 1952 initiated rapid changes over a short period. Overall forest cover was reduced during each semi-decadal interval analyzed, although the vast majority of forest loss (>90%) occurred during between 1947–1960 and 1960–1980 with annual deforestation rates of 2.14% and 3.86%, respectively. The rate dropped to <2% thereafter and has been offset by forest recovery in fallow areas, but overall forest cover has continued to decline. Approximately 27.9% of the study area is forested currently. The region thus shifted from a single contiguous forest to a series of progressively smaller forest fragments. A strong reduction in the amount of core habitat was paralleled by an increased proportion of edge habitat, due to the irregular shape of many forest fragments. Structural connectivity remains high, which may facilitate landscape-level movement for some species.

Conclusions & takeaways

Despite the extent of forest loss, a substantial number of regional landscape-level studies over the past two decades have demonstrated the persistence of many groups of organisms such as birds and mammals. Nonetheless, the continued decline in the quantity and quality of remaining habitat (~30% of existing forest is secondary), as well as the threat of an extinction debt, may result in the extirpation of additional species if more proactive conservation measures are not taken to reverse current trends–a pattern that reflects many other tropical regions the world over.