摘要
利用 2 0世纪 70年代、80年代与 90年代三期遥感资料 ,选取有代表性的 9个有关度量景观空间结构与景观异质性的定量指标 ,通过 FRAGSTATS计算方法 ,系统研究了黄河源区景观生态结构与景观格局变化 ,表明在近 30 a来 ,区域景观空间格局趋于破碎化和多样化 ,其形成与发展的主要内在因素是高寒稀疏化草原草地、黑土化与杂类草草地和沙化草地等景观类型的迅速发展 ,其景观面积分别增加了 384 .1 6 %、6 6 .6 3%和 4 2 1 .0 9% ;选取景观生物生产力、景观土壤养分、景观植被覆盖度等景观功能的表征参数 ,提出了景观格局动态演变下分析景观功能变化的定量方法及其数学模型。在明确近 30 a来区域景观格局演变特征的基础上 ,研究了黄河源区不同时段不同景观类型间生态功能的转移流动特征及其区域生态环境效应 ,表明 :近 30 a来 ,黄河源区景观功能变化强烈 ;区域景观动态演变将形成区域内部景观功能向减退与增强两个方向的变化 ,两个方向的强度均衡将形成区域整体生态功能的特征。研究区域景观格局的动态变化所引起的区域生态功能演变特征 。
The study of landscape heterogeneity is an important means to researching regional ecological processes. According to remote sensing data of 1970s, 1980s and 1990s, some representative quantitative indices of the landscape spatial structure and landscape heterogeneity were selected to study the changes in landscape ecological structure and landscape pattern in the source area of the Yellow River using FRAGSTATS calculation method. In recent 30 years the landscape spatial pattern in the area tended to become fragmentized and diversified, main internal cause for this lies in the rapid development of such landscape types as the alpine cold sparse grassland, black soil-weed grassland and desertified grassland, their areas increased by 384.16% 66.63% and 421.09% respectively. Both the landscape diversity and spatial heterogeneity in the area increased and the change in the landscape pattern was most intense in the 10 years from 1980~1990, such a change reflects the continuous deterioration of eco-environment in the area.; The relationship and feedback between landscape pattern, function and process serve to describe the behavior of a regional landscape. Based on landscape function characteristics such as biological productivity, soil nutrient content, vegetative cover, etc. a quantitative method and digital model for analyzing evolving landscape functionality in the headwaters area of the Yellow River in the People's Republic of China were devised. Through the analysis of three-phase remote sensing data from 1975, 1985 and 1995 and based upon the well-defined characteristics of this region's evolving landscape over the past 30 years, the attendant ecology of the different functional landscape ecotypes was investigated. Between 1975 and 1995 the area of AC&S meadow (alpine cold meadow and steppified meadow) in the source area of the Yellow River has decreased by 27.25%, ACSW meadow (alpine cold swamp meadow) has decreased by 27.04%, ALP steppe (alpine steppe) by 38.18% and lakes by 9.78%. The grass biomass production decreased by 752.37 Gg, of which AC&S meadows accounted for 83.8% of these losses. The overall stock capacity of the headwaters area of the Yellow River decreased by 518.36 thousand sheep units. Soil nutrients showed a similar pattern, soil nutrient loss was greater from 1985～1995 than from 1975～1985. Changes in the overall ecological functionality of the area were not simply a result of a summation of the changes associated with individual evolving landscapes, but rather an integration of positive and negative influences. Landscape evolution occurs in two main directions: degradation and strengthening. An understanding of the direction, force and integration of parameters influencing landscape evolution as it impacts the attending ecosystems can allow one to foresee how the landscape of the Yellow River source area will evolve in the coming years.
出处
《生态学报》
CAS
CSCD
北大核心
2002年第10期1587-1598,共12页
Acta Ecologica Sinica
基金
中国科学院资助项目 KZCX1 -1 0 -0 6
中国科学院"西部之光"计划资助项目
中国科学院寒区旱区环境与工程研究所创新课题资助项目 ( CACX2 1 0 0 4 2 )
关键词
黄河源区
景观格局
生态功能
动态变化
landscape evolution
landscape pattern
transfer matrix
source area of the Yellow River
