[Simulation on the seasonal growth patterns of grassland plant communities in northern China].
Soil moisture is the key factor limiting the productivity of grassland in northern China ranging from arid to subhumid arid regions. In this paper, the seasonal and annual growth, foliage projective cover (FPC), evaporative coefficient (k), and net primary productivity (NPP) of 7 types of grasslands in North China were simulated by using a simple model based on well established ecological processes of water balance and climatic data collected at 460 sites over 40 years. The observed NPPs were used to validate the model, and the simulated NPPs were in high agreement with the observed NPPs. The simulated k, NPP, and FPC deceased from east to west in temperate grasslands, and decreased from southeast to northwest in Qinghai-Tibet Plateau, reflecting the moisture gradient in northern China. Alpine meadow had the highest k, NPP, and FPC in the 7 types of grasslands, alpine steppe had the second highest FPC but with a NPP similar to that of temperate steppe, and the three simulated parameters of temperate desert were the smallest. The simulated results suggested that the livestock density should be lower than 5.2, 2.3, 3.6, 2.1, 1.0, 0.6, and 0.2 sheep unit x hm(-2), while the coverage of rehabilitated vegetation should be about 93%, 79%, 56%, 50%, 44%, 38%, and 37% in alpine meadow, alpine steppe, temperate meadow steppe, temperate steppe, temperate desert steppe, temperate steppe desert, and temperate desert, respectively.
Zhang
Li
L
State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China. zhangli@ibcas.ac.cn
Zheng
Yuan-Run
YR
D002681:China; D003247:Conservation of Natural Resources; D017753:Ecosystem; D008962:Models, Theoretical; D006109:Poaceae / Q000145:classification* / Q000254:growth & development*; D011157:Population Dynamics; D011891:Rain; D012621:Seasons