Submitted as: development and technical paper
| 05 Oct 2018
Status: this preprint was under review for the journal GMD but the revision was not accepted.
Observation-based implementation of ecophysiological processes for a rubber plant functional type in the community land model (CLM4.5-rubber_v1)
Ashehad A. Ali1,Yuanchao Fan2,Marife D. Corre3,Martyna M. Kotowska4,Evelyn Hassler3,Fernando E. Moyano1,Christian Stiegler1,Alexander Röll5,Ana Meijide6,Andre Ringeler1,Christoph Leuschner4,Tania June7,Suria Tarigan8,Holger Kreft9,Dirk Hölscher5,Chonggang Xu10,Charles D. Koven11,Rosie Fisher12,Edzo Veldkamp3,and Alexander Knohl1Ashehad A. Ali et al.Ashehad A. Ali1,Yuanchao Fan2,Marife D. Corre3,Martyna M. Kotowska4,Evelyn Hassler3,Fernando E. Moyano1,Christian Stiegler1,Alexander Röll5,Ana Meijide6,Andre Ringeler1,Christoph Leuschner4,Tania June7,Suria Tarigan8,Holger Kreft9,Dirk Hölscher5,Chonggang Xu10,Charles D. Koven11,Rosie Fisher12,Edzo Veldkamp3,and Alexander Knohl1
Received: 21 Sep 2018 – Discussion started: 05 Oct 2018
Abstract. Land-use change has a strong impact on carbon, energy and water fluxes and its effect is particularly pronounced in tropical regions. Uncertainties exist in the prediction of future land-use change impacts on these fluxes by land surface models due to scarcity of suitable measured data for parametrization and poor representation of key biogeochemical processes associated with tropical vegetation types. Rubber plantations (Havea brasilliensis) are a crucial land-use type across tropical landscapes that has greatly expanded in recent decades. Here, we first synthesize the relevant data for describing the biogeochemical processes of rubber from our past measurement campaigns in Jambi province, Indonesia. We then use these data-sets to develop a rubber plant functional type (PFT) for the Community Land Model (CLM4.5). Field measured data from small-holder plantations on leaf litterfall, soil respiration, latex harvest, leaf area index, transpiration, net primary productivity, and above-ground and fine root biomass were used to develop and calibrate a new PFT-based model (CLM4.5-rubber).
CLM-rubber predictions adequately captured the annual net primary productivity and above-ground biomass as well as the seasonal dynamics of leaf litterfall, soil respiration, soil moisture and leaf area index. All of the predicted water fluxes of CLM-rubber were very similar to a site-specific calibrated soil water model. Including temporal variations in leaf life span enabled CLM-rubber to better capture the seasonality of leaf litterfall.
Increased sensitivity of stomata to soil water stress and the enhancement of growth and maintenance respiration of fine roots in response to soil nutrient limitation enabled CLM-rubber to capture the magnitude of transpiration and leaf area index. Since CLM-rubber predicted reasonably well the carbon and water use, we think that the current model can be used for larger-scale simulations within Jambi province because more than 99 % of the rubber plantations are smallholder owned in Jambi province and have low soil fertility.
We used carbon-use and water-use related datasets of small-holder rubber plantations from Jambi province, Indonesia to develop and calibrate a rubber plant functional type for the Community Land Model (CLM-rubber). Increased sensitivity of stomata to soil water stress and enhanced respiration costs enabled the model to capture the magnitude of transpiration and leaf area index. Including temporal variations in leaf life span enabled the model to better capture the seasonality of leaf litterfall.
We used carbon-use and water-use related datasets of small-holder rubber plantations from Jambi...