PROGRESS IN GEOGRAPHY ›› 2006, Vol. 25 ›› Issue (6): 68-75.doi: 10.11820/dlkxjz.2006.06.008

• Original Articles • Previous Articles     Next Articles

Par ameter ization of Leaf Phenology for the Ter r estr ial Ecosystem Models

GU Fengxue1,2   

  1. 1. Institute of Geographical Sciences and Natural Resources Research, Synthesis Research Center of CERN, Chinese Academy of Sciences, Beijing 100101, China|
    2. Graduate Unviersity of Chinese Academy of Sciences, Beijing 100039, China
  • Received:2006-07-01 Revised:2006-10-01 Online:2006-11-25 Published:2006-11-25


The seasonal phenology of the leaf area index (LAI) is a major determinant of net e-cosystem production in deciduous forest ecosystems. In the simplest case, the effect of leaf phenology on energy and CO2 fluxes is represented by prescribing leaf onset and offset times or the seasonal evolution of LAI. Leaf phenology remains one of the most difficult processes to be parameterized in terrestrial ecosystem models because the understanding of the physical processes that initiate leaf onset and senescence is incomplete. At present, to describe phenology, the terrestrial models generally use one of two different approaches. One approach uses empirical formulations to estimate the timing of crucial phonological events like leaf- on/off dates only based on abiotic variables, especially temperature or growing degree- days (GDDs). The other approach is a carbon - gain - based scheme. In this approach, the phonological stages are directly determined from the current carbon balance. A carbon- gain- based parameterization of phenology in ecosystem models offers the possibility of reduced empiricism, general applicability, and increased robustness; and it is more suitable for being used in climate change models. In the future, while the mechanisms of processes controlling leaf phenology are clarified with progress being made at the physiological and molecular level, ecosystem models have to set up processbased model of leaf phenology and LAI to promote the robust of simulation results.

Key words: ecosystem models, LAI, parameterization, phenology

CLC Number: 

  • P467