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Forests play an important role in mitigating climate change. Forests can sequester carbon from the atmosphere and provide biomass, which can be used to substitute for fossil fuels or energy-intensive materials. International climate policies favor the use of wood to substitute for fossil fuels rather than using forests as carbon sink. We examine the trade off between sequestering carbon in forests and substituting wood for fossil fuels in Finland. For Finland to meet its EU targets for the use of renewable energy by 2020, a considerable increase in the use of wood for energy is necessary. We compare scenarios in which the wood energy targets are fully or partially met to a reference case where policies favoring wood based energy production are removed. Three models are used to project fossil fuel substitution and changes in forest carbon sinks in the scenarios through 2035.Finnish forests are a growing carbon sink in all scenarios. However, net greenhouse gas (GHG) emissions will be higher in the medium term if Finland achieves its current wood energy targets than if the use of energy wood stagnates or decreases. The volume of GHG emissions avoided by replacing coal, peat and fossil diesel with wood is outweighed by the loss in carbon sequestered in forests due to increased biomass removals. Therefore, the current wood energy targets seem excessive and harmful to the climate. In particular, biodiesel production has a significant, negative impact on net emissions in the period considered. However, we did not consider risks such as forest fires, wind damage and diseases, which might weaken the sequestration policy. The potential albedo impacts of harvesting the forests were not considered either.  相似文献   

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The valuation of ecosystem services is intended to facilitate the rational and sustainable utilization of natural resources. However, calculating the values of natural resources is complex, and research is underway in this regard. The change of land use types can reflect the changes in the area of each ecosystem; therefore, in this study, land use changes in Yingkou (located in the south of Liaoning Province and an important port city) over a 10-year period (2004–2014) are assessed using a geographic information systems platform and the 2004, 2009 and 2014 Thematic Mapper remotely sensed images of the area. The Costanza calculation method and classification system are used to estimate changes in the total values of ecosystem services in the Yingkou area from 2004 to 2014 and to investigate the causes of these changes. The “change tendency” of particular ecological communities is calculated using the Variable coefficient, the Gini coefficient, and the Theil index. The results reveal the following: (i) The total value of ecosystem services in the Yingkou area decreased drastically (i.e., from $2567.60 million to $2127.26 million, representing a 17.2% decline) between 2004 and 2014. (ii) Aquatic ecosystem services are valued greater than terrestrial services. In Yingkou, a decline in the value of aquatic ecosystem services accounts for 88.6% of the total decrease in ecosystem service value. (iii) Land reclamation in the Yingkou urban area emerges as the primary factor influencing ecosystem service values for the various ecological communities in the region. The ecosystem service value of each ecological community is different, and the differences between the contributions made by the various communities to the total ecosystem services value are increasing over time. (iv) The decline in ecosystem service values in Yingkou is linked to urban development. Following widespread land reclamation, an increase in land area intended for urban construction is associated with a decrease in water area.  相似文献   

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