Thomas-Hope, Elizabeth M.; Spence, Balfour A.
Author Affiliation, Ana.
Department of Geography and Geology
Promoting agrobiodiversity under difficulties: The Jamaican-PLEC experience
PLEC News and Views
Date of Publication
This article looks at the Jamaica-PLEC experience in promoting agrobiodiversity under very difficult circumstances. More specifically, the demonstration activities of Jamaica-PLEC located in the lower Rio Grande watershed in the Parish of Portland are examined. The Rio Grande valley covers an area of approximately 286,000 hectares, or about one-third of the parish of Portland. The watershed is characterized by high elevations, steep slopes, and is the wettest area in Jamaica. Over 75 per cent of the valley lie above 1500 metres and more than 50 per cent of the area has slopes exceeding 20 degrees. Although highly seasonal, rainfall in the watershed averages 2250 mm annually. The combination of high rainfall, humidity and temperatures results in a diversity of flora, which is unmatched elsewhere in Jamaica. The geology of the Rio Grande watershed consists primarily of friable cretaceous and sedimentary rocks. The dominant formation is the Richmond formation, which is comprised of highly weathered grey to yellow sandstones, siltstones and mudstones. The Rio Grande, which drains the area, is bordered for 50 per cent of its length by alluvial deposits consisting of carbonaceous and silica-rich sands. Steep cultivated slopes, with minimal conservation strategies and high intensity rainfall, contribute to high levels of vulnerability to landslide and flood hazards, as well as soil loss and land degradation. Although this is an area of high agrobiodiversity, increasing emphasis on specialized crops such as banana (Musa sapientum) and the tendency towards reduced interplanting are major contributors to biodiversity loss in the area. The lessons learned by PLEC scientists and farmers alike are also examined.....