|
|
 |
 |
Cameroon Pilot Project:
Cacao Ecology
 |
Researcher: Dr. Lindsey Norgrove
Location: IITA Humid Forest Ecoregional Center, Yaounde, Cameroon
Partners/Funding Organizations: USGS, STCP-IITA, M&M/Mars
Start Date: January 2000
Background
No one has properly defined what is a 'degraded' ecosystem, and it is difficult to relate soil chemical properties to productivity. The ability to decompose plant residues of various qualities is one relative measure of ecosystem function versus degradation. In the Lekie Division of Southern Cameroon, copper-based fungicides (predominantly 'Ridomil Plus' - copper oxide plus metalaxyl) are commonly used in cacao systems to control for black pod phytophthora megakarya. Fungicides may have an impact on the decomposition process. However, at the current cacao price, the spraying regime recommended by the manufacturer is not profitable. Therefore, the effect of a reduced spraying regime is being assessed, as well as the environmental impact of the fungicide.
Objectives
This project will:
- Characterize the ecological and economic factors of existing systems
- Determine landscape level function of cacao systems within a mosaic of different land uses
- Establish cacao systems in degraded land and assess carbon stocks
- Explore the effects of management on ecosystem function and carbon and nutrient c ycling
Results
Material placed in mature cacao systems decomposes at a similar rate to that in forests and much faster than in fallows. This suggests that ecosystem integrity is potentially maintained by cacao.
Fungicide application at the recommended rate has a negative impact upon earthworm cast production. A reduced application is not different from the no-spray control.
In canopy gaps, decomposition rates of fast material are reduced; however, slow decomposing material is unaffected.
Establishing agro forests from degraded land is initially a disturbance, and even after two years, the decomposition ability of the soil is impaired. Fertilizer has no effect so far.
Cacao Ecology.pdf
|
|
