Effects of an experimental drought on the functioning of a cacao agroforestry system, Sulawesi, Indonesia

By L. Schwendenmann, E. Veldkamp, G. Moser, Dirk Hölscher, M. Köhler, Y. Clough, I. Anas, G. Djajakirana, Stefan Erasmi, D. Hertel and 7 more. 2010

133 citations recorded by the source corpus.

Agroforestry systems may play a critical role in reducing the vulnerability of farmers' livelihood to droughts as tree‐based systems provide several mechanisms that can mitigate the impacts from extreme weather events. Here, we use a replicated throughfall reduction experiment to study the drought response of a cacao/Gliricidia stand over a 13‐month period. Soil water content was successfully reduced down to a soil depth of at least 2.5 m. Contrary to our expectations we measured only relatively small nonsignificant changes in cacao (−11%) and Gliricidia (−12%) sap flux densities, cacao leaf litterfall (+8%), Gliricidia leaf litterfall (−2%), soil carbon dioxide efflux (−14%), and cacao yield (−10%) during roof closure. However, cacao bean yield in roof plots was substantially lower (−45%) compared with control plots during the main harvest following the period when soil water content was lowest. This indicates that cacao bean yield was more sensitive to drought than other ecosystem functions. We found evidence in this agroforest that there is complementary use of soil water resources through vertical partitioning of water uptake between cacao and Gliricidia. This, in combination with acclimation may have helped cacao trees to cope with the induced drought. Cacao agroforests may thus play an important role as a drought‐tolerant land use in those (sub‐) tropical regions where the frequency and severity of droughts is projected to increase.

Subfields: Forestry, Global and Planetary Change, Horticulture

View Paper: https://www.semanticscholar.org/paper/0397020270da32d956e5bac341459d1f625cdeeb

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Forestry

1. D. Hertel
2. T. Tscharntke
3. M. Isaac

In Global and Planetary Change

1. M. Kessler
2. D. Hertel
3. Shonil Bhagwat
4. T. Tscharntke
5. M. Isaac
6. I. Perfecto
7. Thomas Cherico Wanger

In Horticulture

1. Y. Clough
2. G. Schroth
3. T. Tscharntke
4. M. Isaac

Citations in the corpus

• Multifunctional shade‐tree management in tropical agroforestry landscapes – a review (2011, background): “In Indonesia, it has been shown experimentally that droughts affect cacao yield (Schwendenmann et al. 2010).”
• Experimental evidence for stronger cacao yield limitation by pollination than by plant resources (2010, methodology): “In a second experiment, we performed a large-scale replicated and controlled drought experiment (Schwendenmann et al., 2010), to our knowledge the first of its kind.”
• Nutrient acquisition strategies in agroforestry systems (2019, background): “…complementarity via root segregation between neighbouring cocoa and and fast growing timber species (Isaac et al. 2014a) and cocoa and the N2-fixing shade tree species, Gliricidia sepium (Schwendenmann et al. 2010) have been confirmed with natural abundance of stable isotopes (δ18O and δ2H).”
• Response of cocoa trees (Theobroma cacao) to a 13-month desiccation period in Sulawesi, Indonesia (2010, unknown): “However, independently of our drought intensity assessment based on Ws, Schwendenmann et al. (2010) reached similar conclusions when calculating the fluctuation of ‘relative extractable water’ in the soil profile of the stand examined here using data for maximum observed water storage and actual…”