SFB 552 - STORMA

Focus 2

"Ecological and socio-economic assessment of agroforestry management: Upscaling from the plot and household level to villages and landscapes"

The main hypothesis that will be tested is: The integrated valuation of environmental and socio-economic benefits of agroforestry, which today represents the last forested land-use type in many tropical landscapes, shows potential synergies and trade-offs of different types of local (fertilization, weeding) as well as regional (site allocation) land-use management.

Aim
Agroforestry systems like the cacao cultivation have potentials in combining socio-economic benefits for farmers with environmental advantages. In many human-dominated tropical landscapes, agroforestry provides the last forested landscapes, often being more diversified than annual cropping systems or pastures. On the other hand, severe trade-offs may exist between short-term financial incentives of cacao agroforestry intensification and the long-term conservation of ecosystem services.
The cultivation of cacao (Theobroma cacao) has a huge impact on livelihoods and landscapes at the margins of the Lore Lindu National Park, Sulawesi. Production is being intensified, with an increase in input use, and a reduction of shade tree cover, resulting in higher yields at least in the short run. At the same time, cacao farmers are suffering increasing losses due to pests and diseases, especially Phytophthora palmivora Butler (Black Pod Disease) and the Cacao Pod Borer Conopomorpha cramerella Snellen, a moth - both are difficult to control using chemical methods. Cacao cash cropping generates much of the farmers income in the project region but there is also evidence that it exposes poorer households to higher socio-economic vulnerability as land is progressively accumulated by the more successful farmers.
Focus 2 aims to answer the following questions through an integrated valuation of environmental and socio-economic benefits of cacao agroforestry:
What are the potential synergies and trade-offs of different types of local (fertilization, weeding) as well as regional (site allocation) land-use management?
What is the value of ecosystem services associated with different management intensities?
Does intensification threaten biodiversity conservation value in cacao agroforestry?
What are the causes and consequences of increasing cacao agroforestry with respect to marginal economic benefits of alternative land use, social mechanisms of forest conversion, different household types and their vulnerability to social and environmental change?

Methods: Cacao agroecological experiment
A two year study is being conducted since November 2006 on 44 cacao plots (0.16 ha each) in two valleys with contrasting land-use histories and abiotic factors. The plots are along independent gradients of distance to forest, shade intensity and shade tree diversity
Plots are divided into a fertilized (100 kgN/ha every 6 months) and an unfertilized subplot. Half of all plots weeded every 3 months, the other half every 6 months. Researchers will investigate how management intensification and landscape context affects:
the diversity of plants, arthropods and birds; arthropod pests as well as predators, parasitoids and pollinators and the services they provide; potentially beneficial endophytic fungi; soil properties, fungal and bacterial biomass.
Recording of input and outputs will enable the placement of the results into the socio-economic context and the linkage with the results of the survey (see below).

Cacao socio-economic survey
A detailed micro-economic study of cacao agroforestry was started in January 2007, recording precise data on management, input and output of 144 cacao plots in 12 villages of the study area, allowing the upscaling of experimental data from plots to villages and landscapes. The plot are categorized into four intensification steps (no shade; 0% < low shade <30%; 30% < medium shade < 75%; much shade/ natural forest cover >75%), for the later assessment of marginal net benefits along an intensification gradient. Farmers document their harvests and inputs weekly, for a total duration of 10 months.
A complementary choice experiment on the willingness-to-pay for non-market goods like environmental services and biodiversity will be conducted in May 2007, completing a data set already available for the 12 village sample.
For an identification of different household types involved in cacao agroforestry, in-depth studies will take place in selected focus villages, including also the assessment of the vulnerability to social and environmental change and the adaptability of technological innovations, also with respect to future ENSO droughts.