According to the „Intensification hypo-thesis, more intensive forms of agriculture change the belowground part of the agro-ecosystem and leads to a loss of soil biodiversity due to reduction in amount and diversity of organic inputs to the belowground foodwebs, through the use of agro-chemicals and by modifi-cation of the microclimate. The changes in belowground biodiversity may affect functionally important groups, such as symbionts (important in nutrient cycling), ecosystem engineers (maintaining water infiltration into the soil), and predators (pest and disease control). When certain thresholds are passed, hydrological functions become affected, as diminished infiltration induces surface runoff and erosion, resulting to a downward spiral of degradation. Such thresholds, however, are poorly defined as yet and involve both the production of agricultural goods, as wellas ecosystem services. Tests of the „intensification hypothesis; as such are scarce and require that the concept of land use intensity can be assessed without ambiguity. In this introduction to research results obtained in the Sumberjaya (West Lampung) benchmark area of ASB (Alternatives to Slash and Burn) and the CSM-BGBD (Conservation and Sustainable Management of Belowground Biodiversity), we introduce a quantitative index of land use intensity, that builds on the Ruthenberg index but also includes aspects of the water and nutrient balance, the use of external energy and agrochemicals. The values of the index range from below 0.5 for logged-over forest and Imperata grassland patches, to values of 1-3 for agroforests and extensive agriculture and values of 3 - 20 for monocultural coffee gardens and intensive horticulture and agriculture. Thresholds, related to this index may help inform farmers and policy makers on the value of biodiversity conservation to maintenance of environmental services.
Année de publication
2006
Auteurs
van Noordwijk, M.; Hairiah, K.
Langue
Indonesian
Mots clés
agroforestry, biodiversity, agroecosystems, agricultural intensification
Géographique
Indonesia
