Land use changes of river segment ecosystems from the Lancang River and Yuanjiang River were studied from 1985 to 2000 in order to compare their changes of service values and analyze the driving mechanisms based on eco-economic and GIS methods. Results showed that forest areas in both the river segment ecosystems were reduced. The reduced forest in the Lancang River (LR) segment ecosystem was mostly transformed into glebe with the conversion rate of 56.0%, while the reduced forest in the Yuanjiang River (YR) segment ecosystem was mostly transformed into residence land with the conversion rate of 42.5%. Both change amount and change rate of areas of each land use type in the LR segment ecosystem were much larger than those in the YR segment ecosystem. The total service value of the LR segment ecosystem was decreased with the change rate of 15.3%, while that of YR segment ecosystem was increased with the change rate of 0.6%. Manwan Hydropower development was the major anthropogenic driving factor which led to the change of service value of the LR segment ecosystem with the contribution rate of 93%. Agricultural activities were the most important driving factors in the YR segment ecosystem with the contribution rate of 59%. The loss of value of Sediment transportation service resulting from Manwan Hydropower Project construction should take responsibility for the significant decrease of service value of waters, even for the whole LR segment ecosystem. The ecosystem service coefficients of forest and grassland in the study area were much higher than the average level in China, so were the ratios of indirect value to direct value of both the river segment ecosystems. Under the impacts of human activities, the capacity of river ecosystem for providing products was enhanced, while it was weakened to maintain natural ecosystem health.
相似文献Based on the land use (LU) (in 1985 and 2000) and road networks (RN) data in the Longitudinal Range-Gorge Region (LRGR), ecosystem services value (ESV) loss under the disturbance of road networks was estimated by using landscape degradation index (LDI) to clarify the effects of human activities on ecosystem service function (ESF). Results show that the ESV decreased more than 65×108 Yuan (RMB) due to the transformation of ecosystems in the study area during the past 16 years. The ecosystems influenced by road networks of different grades account for 5.4% of the total land in the study area. The ecosystems lost their ESV of 1900×108 Yuan (RMB) by the disturbance of RN. The effect of RN on the ESV decreased exponentially. The forecast shows that ESV will be decreased 1.2%/a on average in 2010 and 2020 due to RN projects. The effect of ecosystem structure change on ESV was complex and nonlinear. The disturbance of RN, one of the human activities influencing ESF is considered, further study and new method should be developed to accurately estimate the loss of ESV and the ecosystem function.
相似文献The impact of highway construction upon surrounding ecosystems in the Longitudinal Range-Gorge Region of Southwestern China was detected based on field survey and experimental analysis. We conducted a study on Dali (from Dali City to Lijiang City) provincial road, Dabao (from Dali City to Baoshan City) highway and Baolong (from Baoshan City to Longling County) highway in the Longitudinal Range-Gorge Region to detect the effect of highway construction on surrounding soil quality using the method of space-for-time substitution, and predicted remediation of surrounding soil quality. The results showed that: (1) The effect of highway construction on both natural and cultivated soil quality is significant, and the effect is more significant in the period of highway construction than the period of highway in use. (2) The effects of highway construction is more apparent on downslope than upslope, and effect range was 200 m on downslope, while 150 m on upslope. (3) Soil remediation is mainly related to effect extent of highway construction, highway service time, vegetation restoration, soil organic matter and soil total nitrogen, among which, highway construction is the most important factor. (4) When vegetation coverage can be restored to 30% of the original condition, soil quality can be remedied to 44% of the original condition after 10 years, indicating that soil fertility remediation is rather difficult once it is destroyed.
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