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1.
We review the available data that can be used to assess the potential impact of climate change on vegetation, and we use central Spitsbergen, Svalbard, as a model location for the High Arctic. We used two sources of information: recent and short-term historical records, which enable assessment on scales of particular plant communities and the landscape over a period of decades, and palynological and macrofossil analyses, which enable assessment on time scales of hundreds and thousands of years and on the spatial scale of the landscape. Both of these substitutes for standardized monitoring revealed stability of vegetation, which is probably attributable to the harsh conditions and the distance of the area from sources of diaspores of potential new incomers. The only evident recent vegetation changes related to climate change are associated with succession after glacial retreats. By establishing a network of permanent plots, researchers will be able to monitor immigration of new species from diversity 'hot spots' and from an abandoned settlement nearby. This will greatly enhance our ability to understand the effects of climate change on vegetation in the High Arctic. 相似文献
2.
Mikołaj Piniewski Ignacy Kardel Marek Giełczewski Paweł Marcinkowski Tomasz Okruszko 《Ambio》2014,43(5):644-660
Currently, there is a major concern about the future of nutrient loads discharged into the Baltic Sea from Polish rivers because they are main contributors to its eutrophication. To date, no watershed-scale studies have properly addressed this issue. This paper fills this gap by using a scenario-modeling framework applied in the Reda watershed, a small (482 km2) agricultural coastal area in northern Poland. We used the SWAT model to quantify the effects of future climate, land cover, and management changes under multiple scenarios up to the 2050s. The combined effect of climate and land use change on N-NO3 and P-PO4 loads is an increase by 20–60 and 24–31 %, respectively, depending on the intensity of future agricultural usage. Using a scenario that assumes a major shift toward a more intensive agriculture following the Danish model would bring significantly higher crop yields but cause a great deterioration of water quality. Using vegetative cover in winter and spring (VC) would be a very efficient way to reduce future P-PO4 loads so that they are lower than levels observed at present. However, even the best combination of measures (VC, buffer zones, reduced fertilization, and constructed wetlands) would not help to remediate heavily increased N-NO3 loads due to climate change and agricultural intensification. 相似文献