关键词: 生物量估测, 胡杨(Populus euphratica), 一级枝, 树冠, 塔里木河下游

Abstract:

Mathematical statistics methods were applied to establish the biomass estimation models of first-class branch and canopy of Populus euphratica. Eighty first-class branches data  were collected in the sampling plots which were distributed 500-300 m distance to the river in Yingsu and Ka'erdayi section in the lower reaches of Tarim River.The best estimation models for each of them were picked out based on accuracy test, and then the significance of the difference between estimated value and measured value was tested according to Chi-square way. It was found that the equation model, Sb=125.546(D2L)0.654 (Sb, D and L refer to biomass, base diameter and length of first-class branch, respectively), which by using D2L as parameter was best to estimate the biomass of first-class branch, while the best equation model used to estimate canopy biomass was Sc=0.016A2+2.291A+11.084(Sc, and A refer to biomass and area of canopy, respectively), in which canopy area was used as parameter. Both of them can be applied to estimate the biomass within 300 m distance to the river, the accuracy of them was 93.75% and 87.01% respectively, but both of them must be modified when used in the range of 600 m to 1 500 m distance to the river, and the accuracy of them was 86.04% and 84.32% respectively after modified. According to the data of stem volume density (748.43 kg\5m-3) acquired (by harvest method and every tree measured in each square, to calculate the biomass of stem and crown of P. euphratica by using biomass estimation models, subsequently, the total aboveground biomass of P. euphratica was acquired. This study can provide direct evidence for the RS estimation of biomass and carbon storage study of P. euphratica in the reaches of Tarim River.

Key words: biomass estimation, Populus euphratica, first-class branch, canopy, Tarim River