Measuring leaf area index in Asian rubber plantations – a challenge
- Publication Type
- Journal contribution (peer reviewed)
- Authors
- Cotter, M., Asch, F., Hilger, T., Rajaona, A., Schappert, A., Stuerz, S., Yang, X.
- Year of publication
- 2017
- Published in
- Ecological Indicators
- Band/Volume
- 82/
- DOI
- 10.1016/j.ecolind.2017.07.019
- Page (from - to)
- 357-366
In order to estimate water use, water requirements and carbon sequestration of tropical plantation systems such as rubber it is adamant to have accurate information on leaf area development of the plantation as the main determinant of evapotranspiration. Literature commonly suggests a number of different methods on how to obtain leaf area index (LAI) information from tree plantation systems. Methods include destructive measurements of leaf area at peak LAI, indirect methods such as gap fraction methods (i.e. Hemiview and LAI 2000) and radiation interception methods (i.e. SunScan) or litter fall traps. Published values for peak LAI in rubber plantation differ widely and show no clear trend to be explained by management practices or the influence of local climate patterns. This study compares four methods for determining LAI of rubber plantations of different ages in Xishuangbanna, Yunnan, PR China. We have tested indirect measurement techniques such as light absorption and gap fraction measurements and hemispherical image analysis against litter fall data in order to obtain insights into the reliability of these measuring techniques for the use in tropical tree plantation systems. In addition, we have included data from destructive harvesting as a comparison. The results presented here clearly showed that there was no consistent agreement between the different measurements. Site, time of the day and incoming radiation all had a significant effect on the results depending on the devices used. This leaves us with the conclusion that the integration of published data on LAI in rubber into broad ranging assessments is very difficult to accomplish as the accuracy of the measurements seems to be very sensitive to a number of factors. This diminishes the usefulness of literature data in estimating evapotranspiration from rubber plantations and the induced environmental effects, both on local as well as regional levels.
Involved persons
- Dr. sc. agr. Marc Cotter
- Prof. Dr. Folkard Asch
- Dr. agr. Thomas H. Hilger
- M.Sc. Alexandra Schappert
- Dr. agr. Sabine Stürz
Involved institutions
- Institute of Agricultural Sciences in the Tropics (Hans-Ruthenberg-Institute)
- Management of Crop Water Stress in the Tropics and Subtropics
- Agronomy in the Tropics and Subtropics
- Hohenheim Tropen