GRE Reading Comprehension: JiJing 352-GRE阅读机经352篇 - F5X4K69252H250M2K

There is mounting evidence that the frequency and magnitude of land-sliding is changing in many parts of the world in response to climate change. This is not surprising, given that precipitation is one of the two external triggering mechanisms – the other being seismic activity – involved in the formation of landslides. Evidence from the past clearly indicates that cycles of elevated landslide activity have been followed by cycles of low activity, and that these are correlated with climate fluctuations over a variety of timescales. What sets current changes in landslide activity apart is the likely influence of anthropogenic [i.e., human-caused] factors, either acting alone or in concert with climate, which can further modify the process of land-sliding and the nature of ecosystem responses. Among these factors, deforestation and land-use change have the potential to influence the frequency and magnitude of land-sliding because of their direct effects on vegetation attributes that influence slope stability. The extent and conditions under which mountain ecosystems are resilient to these changes – that is, the amount of disturbance they can absorb before changing into states with different structure and function – are not known. Addressing this issue is crucial for the long-term conservation of mountainscapes.