黔东北岩溶地区天然暖性草地变化分析

Analysis for the changes of the naturally warm grasslands from the karst areas in northeastern Guizhou

为了探明铜仁市天然草地变化趋势,掌握草地变化规律,为铜仁市石漠化治理提供科学依据,通过2007—2012年采取定点监测方法,对碧江区、德江县、江口县、印江县、石阡县9个样地进行观测,从草丛高度、植被盖度和草产量3个指标进行分析。结果表明:铜仁市岩溶地区天然草地发展变化总体稳定,呈正向演替变化;降雨因素成为岩溶地区天然草地的关键影响因素;草层高度、盖度与年产草量的变化走势图多呈"波浪形",这与年份间的降雨量有极大的关系;草层高度、植被盖度与年总产草量间存在相关性,相关系数分别为0.822,0.676,经多元线性回归分析,三者间的线性方程为:Y=3.030X1+3.622X2-208.020。

To explore the changing trends in the natural grasslands from Tongren city, and grasp the variation of the grasslands, providing a scientific basis for controlling stony desertification in Tongren city. The fixed - point monitoring method was used for observing the nine plots from Bijiaug District, Dejiang County, Jiangkou County, Yinjiang County, Shiqian County from 2007 to 2012, and then the three indexes from the plots including grass height, vegetation coverage and forage yield were analyzed, respectively. The results showed that the development and changes of the natural grasslands from Tongren city were generally stable, showing positive succession changes; the rainfall factor was a critical factor affecting natural grassland from the karat areas ; The trend charts of grass height and vegetation coverage with annual grass yield were most- ly in wavy form, this had a great relationship with annual rainfall ; there was a correlation both grass height and vegetation coverage with the annual total yield of grass, and their correlation coefficients were 0. 822 and 0. 676, respectively. Through the analysis of the multiple linear re- gression, the linear equation among three of them, was Y = 3. 030X1 ＋ 3. 622X2 - 208. 020.