Author(s): Xilai Li; George L. W. Perry; Gary J. Brierley; Jay Gao; Jing Zhang
Linked Author(s):
Keywords: Lpine meadow; Grazing intensities; Plant-functional type; Spatially explicit simulation model; Sanjiangyuan region on the QTP
Abstract: Overgrazing, along with small mammal outbreaks, has been considered a primary reaso n for the increased degradation of alpine meadows in the Sanjiangyuan region on the Qinghai -Tibetan Plateau (QTP). Plant-functional type (PFT) communities have been dramatically affected by such degradation. Field-based studies of PFT communities affected by degradation are inevitably short-term and local, and therefore struggle to reveal PFT patio-temporal dynamics during and after degradation. Such problems can, at least partly, be resolved using spatially explicit simulation modelling drawing on contemporary understanding of these ecosystems. A grid -based model was developed, based on field studies and existing literature, to assess controls upon grassland degradation and prospective restoration strategies using model experiments. In this study, the underlying modelling approach and rationale are discussed. Some issues about grid-based (discrete space) and spatially explicit models are introduced before details of the spatial and temporal scale, implementation (in Netlogo), model rules, and procedure modules are described. The key purpose of this study is to explain the nature of background information that underpins the model, and to detail the structure and process of the model and NetLogo platform. During the process of Heitutan degradation, the plant functional types (PFTs) population dynamics and their habitats have changed dramatically. Thus, the model description of spatially explicit modelling of four PFTs populations in alpine meadow as affected by human activities, such as over-grazing, is described in this paper. Five key modules related to the structure and processes of the simulation model are explored in detail.
Year: 2013