西南喀斯特断陷盆地植被物候动态变化及其与气候因子的响应
李 丹1,2, 吴秀芹1,2, 张靖宙1,2, 于 洋3

(1.北京林业大学 水土保持学院, 北京 100083; 2.北京林业大学 水土保持国家林业局重点实验室, 北京 100083; 3.中国水利水电科学研究院 泥沙研究所, 北京 100048)

西南喀斯特断陷盆地; 植被物候; 气候变化; NDVI

Vegetation Phenology Change and Response to Climate Change in the Karst Faulted Basin of Southwest China
LI Dan1,2, WU Xiuqin1,2, ZHANG Jingzhou1,2, YU Yang3

(1.School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China; 2.Key Laboratory of Soil and Water Conservation of State Forestry Administration, Beijing Forestry University, Beijing 100083, China; 3.Department of Sediment Research, China Institute of Water Resources and Hydropower Research, Beijing 100048, China)

karst faulted basin; vegetation phenology; climate change; NDVI

备注

为了解喀斯特断陷盆地植被物候格局以及植被物候变化的驱动机制,基于2001—2016年MOD13Q1的250 m产品,利用TIMESAT模型最大斜率法反演了西南喀斯特断陷盆地生长季始期(SOS)、生长季末期(EOS)和生长季的长度(LOS)及变化,并深入分析了影响物候变化的主要气候因素。结果 表明:(1)2001—2016年期间,西南喀斯特断陷盆地生长季初期物候指标推迟了7.7 d/10 a,生长季末期物候指标推迟了10 d/10 a,生长季长度指标延长了2.3 d/10 a。(2)SOS变化整体呈现西推迟东提前的变化趋势,提前趋势显著的地区集中分布于研究区东部云贵边境; 大部分地区生长季结束日期推迟,但安宁河谷、木里低海拔山谷等少部分地区生长季结束日期显著提前。(3)物候指标对气温和降水的响应程度不同,总体来讲,SOS受气候因子的影响比EOS更强烈。春季气温和降水对植被SOS影响力普遍大于其他季节,SOS的推迟现象主要受到春季温度升高的影响。夏季降水对EOS的影响较大,表明植物生长受降水的影响存在一定的时滞作用。在增温增湿的气候背景下,断陷盆地物候指标在呈现出东早西晚的空间分异情况下随之发生推迟的响应关系。水分是限制植被生长的主要因素,且对植被的影响主要体现在春季和夏季。

In order to understand the vegetation phenology pattern and explore the driving mechanism of vegetation phenology change in karst faulted basin, based on the 250 m product data of MOD13Q1 from 2001 to 2016, three vegetation phenological indices(the start of the growing season, the end of the growing season, the length of the growing season)were estimated to study the vegetation phenological changes by using TIMESAT model in southwest karst faulted basin. And then the main factors affecting phenology change were analyzed. The results showed that:(1)from 2001 to 2016, SOS of karst basin of southwest China experienced a delay of 7.7 d/decade, EOS experienced a delay of 10 d/decade, and LOS prolonged 2.3 d/decade;(2)the change of SOS in the research area reflected postponement in the west and advance in the east; the areas with significant advance trend concentrated in the Yunnan-Guizhou border of the eastern research area; in most regions, EOS presented the delay trend, but in a few regions, EOS presented the advance trend, such as Anning River valley, Muli low-elevation valley;(3)the response of phenological index to temperature and precipitation was different; in general, SOS was more strongly affected by climate factors than EOS; the influence of spring temperature and precipitation on SOS was generally greater than that in other seasons in the whole study area; the delay of SOS was mainly affected by the temperature rise in spring; summer precipitation had a great influence on EOS, which reflected that precipitation had a certain time lag on plant growth. Under the climate background of increasing temperature and humidity, phenological indexes of faulted basins show the spatial differentiation of the early pattern in east and the later pattern in west and indicate the delayed response relationship with climate change. Water is the main factor limiting vegetation growth, and mainly presents the impact on vegetation in the spring and summer.