From shade- to sun-grown perennial crops in Sulawesi, Indonesia: implications for biodiversity conservation and soil fertility
Traditional, complex forest farming systems are increasingly convertedto sun-grown monocultures throughout the tropics. Biophysical, soil andbiodiversity effects associated with sun- vs. shade-grown coffee and cacao wereinvestigated in a case study in Sulawesi, Indonesia. Canopy height, tree,epiphyte, liana and bird species diversity, vegetation structural complexity,percent ground cover by leaf litter, and soil calcium, nitrate nitrogen andorganic matter levels in the O horizons were all significantly greater in shadedthan in sun-grown farms. In contrast, photosynthetic active radiation (PAR), airand soil temperatures, weed diversity and percent ground cover by weeds weresignificantly greater in sun compared to shade farms. At the landscape level,conversion of shade-grown crops to sun conditions isolates protected areas andremnant primary forest fragments. Local cultivators are cognizant of theagronomic and socioeconomic risks associated with sun-grown perennialmonocultures and some are increasing the density and diversity of fruit treecultivation in an effort to provide shade and organic matter, and increase anddiversify crop yields. The maintenance of traditional, complex forest farmingsystems, particularly shade-grown perennial crops, warrants greater attention inagricultural development and biodiversity conservation efforts.