Dynamic Variations of Landscape Pattern and the Landscape Ecological Functions in the Source Area of the Yellow River
Dynamic Variations of Landscape Pattern and the Landscape Ecological Functions in the Source Area of the Yellow River
复制标题
DOI：
--
复制
发表时间：
2002
影响因子：
--
通讯作者：
Genxu Wang;Xiao-Yin Guo;G. Cheng
中科院分区：
文献类型：
--
作者：
Genxu Wang;Xiao-Yin Guo;G. Cheng
景观异质性研究是研究区域生态过程的重要手段。根据20世纪70、80和90年代的遥感数据，选取景观空间结构和景观异质性的代表性定量指标，采用FRAGSTATS计算方法，研究黄河源区景观生态结构和景观格局的变化。近30年来，该地区景观空间格局趋于破碎化和多样化，其主要内因是高寒稀疏草地、黑土-杂草草地和荒漠化草地等景观类型迅速发展，面积分别增加了384.16%、66.63%和421.09%。1980~1990年的10年间，该区景观多样性和空间异质性均有所增加，景观格局变化最为剧烈，反映了该区生态环境的持续恶化。景观格局、景观功能和景观过程之间的相互关系和反馈作用是描述区域景观行为的基础。以生物生产力、土壤养分含量、植被覆盖度等景观功能特征为基础，建立了中华人民共和国黄河源区景观功能演变的定量分析方法和数字模型。通过对1975年、1985年和1995年三期遥感资料的分析，根据近30年来该区景观演变的明确特征，对不同功能景观生态类型的伴随生态进行了研究。1975 ~ 1995年，黄河源区ACS草甸（高寒草甸和草原化草甸）减少了27.25%，ACSW草甸（高寒沼泽草甸）减少了27.04%，ALP草原（高寒草原）减少了38.18%，湖泊减少了9.78%。草地生物量减少752.37 Gg，其中ACS草地占83.8%。黄河源区总体存栏量减少51.836万只羊单位。土壤养分变化规律相似，1985~1995年土壤养分流失量大于1975~1985年。该地区整体生态功能的变化不仅仅是与个别景观演变相关的变化的总和，而是积极和消极影响的综合结果。景观演变有两个主要方向：退化和强化。了解景观演变的方向、力量和影响景观演变的参数的整合，因为它影响到参与生态系统，可以让人们预见黄河源区的景观将如何演变，在未来几年。
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 ACS 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 ACS 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.