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1.
1IntroductionAlmostaloflandscapesarespatialyheterogeneousmosaicsoflandcoverorhabitat(Forman,1995).Thespatialarangementorspat...  相似文献   

2.
TheglobalclimatechangeandforestpredictioninChinaJiangYouxuForestryInstitute,ChineseAcademyofForestry,Beijing100091,ChinaThegl...  相似文献   

3.
The study of effects of acid rain in Southwestern China on forest ecosystems .has been inrestigated since 1984. The results have shown that the ecosystem of Pinus massoniana forest has been damaged severely by acid rain. Comparing the areas where the annual mean pH value is lower than 4.5 with that higher than 4.5, the productivity of the ecosystems decreased 50 percent. Both the percentages of the green leaves and the content of chlorophyll cut down; the acidity of soil increased a bit and the fertility showed the tendency to lower. The microbial population components in surface soil were changed and the total number of soil microbes reduced from 63.5 to 92.6 percent. Besides the direct effects of acid rain, the insect pest, especially, Blastophagus piniperdoz and Monochamus galloprovincialis, seized the opportunity to enter and reproduce in it so as to aggravate the forest dieback of P.massoniana in the areas where the annual average pH value is lower than 4.5.Additionally, the simulation study on the  相似文献   

4.
IntroductionLandscapeboundaries,ortransitionalzones ecotonesamongdifferentlandscapes,haveoftenbeenignoredorreducedtolinesonamapwhenecologistsstudied .Howeverlandscapeboundariesareinherentfeaturesoflandscapesandplayimportantrolesinecosystemsdynamics.Fora…  相似文献   

5.
1IntroductionThedevelopmentofforestryhasmadeagreatproductivityintheThreeGorgeReservoirareainChina,anditreachedmuchdesirablebi...  相似文献   

6.
Boundaries between different forest types in Changbai Mountain Eatern China are results from complex interactions between forest ecosystems,topogrphy,and geomorphology.Detecting and quantifying the transitional zones are highly important since high environmental beterogeneity and biodiversity are ofter found within these zpmes.In this study,we used GIS and multivariate statistics techniques(PCA and MSWA) to analyze data from Landsat TM satellite imageries and quantitatively determined the positions and widths of the landscape boundary betweeen mountain birch and evergreen coniferous forests in the northern slope of Changbai Mountain.The results showed that the widths of the landscape boundary ranges from 30-50 m while using the MWW A or/and PC method.Such detected widths are consistent with field transect data that suggest a 50m tranistional zone width.The results further suggest that TM data can be used in combination with GIS and statistical techniques in determining forest landscape boundaries.MSWA is more reliable than PCA,while PCA can also be used to determine the landscape boundary when transects are properly located.  相似文献   

7.
We have investigated value arguments concerning forest policy in Finland and reflected on their prevalence in an international context. The arguments of the organised stakeholders of current forest policy are analysed using semi-structured interview data and secondary material. We have categorised these arguments, and based on them, constructed value positions. The explorative rhetoric analysis reveals shared as well as conflicting values and beliefs.We have identified two dominating value positions: forestry position and nature position. The recognised core values include utility, property rights and value of nature, the utility dominating the policy discussion scene. A principal feature of the polarised policy field is a lack of trust. In addition to the polarisation, there is also a broad common ground in positions towards traditional rights of ownership and access to forests as well as on citizens’ rights to influence forest policy. In order to gain more influence in forest policy, both positions make an effort to redefine the concepts in the argumentation of the others.  相似文献   

8.
The aim of this paper is to discuss the reasonable method to set up the man-made ecosystem where the high productivity, high economic effects and ecological efficiencies, continual resources and suitable environment could be obtained.  相似文献   

9.
N2OemisionsfromforestandgraslandsoilsinnorthernChinaLiuYe,MuYujing,YangWenxiangResearchCenterforEcoEnvironmentalSciences,Ch...  相似文献   

10.
The masson pine (Pinns massoniana Lamb.) forest of 2000 ha situated on Nanshan, the south bank of the Yangtze River near Chongqing, China. From 1982, some trees began to die. Since then, half of the trees have died and the whole forest is in danger. Prom November 1986 to January 1987, a study dealt with the characteristics of fogwater in that area was carried out, in order to explain the relationship between acid fog and masson pine decline. The results of our study showed that the acid fog might be responsible in part for the decline of the masson pine forest.  相似文献   

11.
1IntroductionPrecipitationisanimportantsourceofnutrientinputtoforestedecosystems,especialywhererockweatheringisslow(Parker,19...  相似文献   

12.
This study investigates the influence of policy interests on resource sustainability. Information on ‘colonial interest’ of the British regime and the ‘commercial interest’ of the post-colonial regimes on forest land use of Bangladesh have been drawn on to show the interplay of interests on sustainability impacts. The findings show that both colonial and commercial interests have caused intensification of forest land use for production of economic crops like teak (Tectona grandis) and cash crops like tea (Camellia sinensis), cotton (Gossypium herbaceum and G. arboreum) and tobacco (Nicotiana tabacum). The ‘colonial interest’ has also initiated the dispute of ownership, rights and tenure of forest land and resources. The post-colonial regimes have utilized colonial legacy as the privilege for implementing ‘commercial interests’. In both the cases traditional interests of people were disregarded. As a result, peoples’ participation in forestry was discouraged and the sustainability of forest land use was impeded.  相似文献   

13.
Nitrous oxide(N2O)is a major trace gas in the atmosphere.It plays an important rote in global warming and zone depleting.In this paper,we set up a install to determine the N2O emission flux from forest and grassland soil.We observed an interesting phenomenon:in our sampling sites,the soil always acts as a source of N2O,but sometimes it acts as a sink when the temperature is lower than 15℃.  相似文献   

14.
Forests play a fundamental role in the global carbon cycle and can be managed to mitigate greenhouse gas emissions and conserve or sequester carbon. Global policy and environmental changes can affect regional consumption of forest products, as well as inter-regional trade of forest goods and services. This study analyzes global and regional change impacts on the production, consumption and trade of forest products in two Nordic countries, Finland and Sweden. Annual data on removal and trade (1964–2012) for roundwood and sawnwood is used to identify structural breaks based on Chow tests. According to the analysis, the time period is divided into two periods: t1 (1964–1980) and t2 (1981–2012). In the first period, breaks occurred in 1975 and 1976 in the Finnish model and no break is found in the Swedish model. In the second period, we identify breaks in 1991 and 1992 for the Finnish model and in 2004, 2005 and 2006 for the Swedish model. Although our findings have broad empirical support, we do not identify any specific incident as a direct cause of the changes in the consumption and trade patterns of the two types of wood in these countries. The models and analysis presented here can serve as methodological tools for policymakers to better understand the effects of structural changes in the production of forest goods and services in the Nordic region and globally.  相似文献   

15.
Promoting sustainable forest management as part of the reduced emissions from deforestation and degradation in developing countries (REDD)-plus mechanism in the Copenhagen Accord of December 2009 implies that tropical forests will no longer be ignored in the new climate change agreement. As new financial incentives are pledged, costs and revenues on a 1-ha tract of tropical forestland being managed or cleared for other land use options need to be assessed so that appropriate compensation measures can be proposed. Cambodia's highly stocked evergreen forest, which has experienced rapid degradation and deforestation, will be the first priority forest to be managed if financial incentives through a carbon payment scheme are available. By analyzing forest inventory data, we assessed the revenues and costs for managing a hypothetical 1 ha of forestland against six land use options: business-as-usual timber harvesting (BAU-timber), forest management under the REDD-plus mechanism, forest-to-teak plantation, forest-to-acacia plantation, forest-to-rubber plantation, and forest-to-oil palm plantation. We determined annual equivalent values for each option, and the BAU-timber and REDD-plus management options were the highest, with both options influenced by logging costs and timber price. Financial incentives should be provided at a level that would allow continuation of sustainable logging and be attractive to REDD-plus project developers.  相似文献   

16.
Mitigation and Adaptation Strategies for Global Change - This paper was published on March 2017, Volume 22, Issue 3, 469–483pp, titled “Identification of structural breaks in the forest...  相似文献   

17.
The cycling characteristics of nitrogen(N), phosphorus(P) and potassium(K) of the Quercus acutissima and Pinus massoniana mixed forest, which is the most common forest type in the Three Gorge Reservoir areas in China, were systematically analyzed. The results showed that N, P and K accumulated in the plant pool and in the litter pool, while total N, P, and K were deficient in the soil pool and in the forest systems. Contents of N in the soil of depth 20-40 cm were the key factor limiting growth of trees. The biological outside cycling coefficients were 8.78, 72.5 and 11.7 times of inside cycling coefficients of N, P and K, respectively. 33.92, 10.26 and 15.88 kg of N, P and K return to the litter pool from branches, leaves and throughfall per year, but, 14.31, 1.32 and 10.48 kg of N, P and K return to the soil from litter pool per year respectively. It is clear that 58% of N, 87% of P, and 34% of K are lost by surface runoff per year. 5.49%, 1.30%, and 8.34% of N, P and K withdraw from leaves to branches, 4.99%, 1.99% and 7.30% of N, P and K withdraw from branches to trunks per year,respectively.  相似文献   

18.
This article draws lessons from a seven-year project on conservation and use of remaining coffee forests in the highlands of South-west Ethiopia. The project investigated the genetic diversity of Coffea arabica in its place of origin as well as economic perspectives of quality coffee marketing. With initially broad multidisciplinary natural and social sciences research a basis was laid for a second phase of praxis and implementation-oriented research in the same region.As a key innovative approach an NGO was established to take over all project management and implementation-oriented work in Ethiopia at the beginning of the second phase. This initiative helped decisively to solve the kind of problems identified in RESCUE (2012): ownership of results developed within R&D, the often missing mandate for science to actively contribute to solutions ‘on the ground’, and problems of cultural and social unsuitability and misunderstanding, which often are at the core of the problem when solutions from scientists are expected.The NGO operated as an intermediary between the involved scientists and other stakeholders from the coffee industry as well as from public administration and the Ethiopian polity. Its overall target was to contribute toward establishment of a biosphere reserve following the UNESCO MAB scheme and to use this scheme for the conservation and use of the remaining Ethiopian coffee forests. This target was achieved: the biosphere reserve has been accepted and accredited by UNESCO and is in operation. In addition, quality coffee from the development zones of the biosphere reserve is being sold on local markets in Yayu, SW Ethiopia.There are important lessons for the future of transdisciplinary and transformative sustainability science that can be drawn from this experience. These lessons concern concrete challenges and chances of research and development geared toward sustainable development:
  • •Working with implementation-targets as project organizing elements,
  • •communication and transfer of responsibility to involved stakeholders,
  • •challenges for praxis-oriented syntheses from research results,
  • •practical challenges of management and coordination for transdisciplinary projects, as well as.
  • •chances for long-term sustainability and use of research and implementation work.
These lessons are described in this article with the overall intention to draw conclusions and to make them more widely available for scientists and project coordinators working in transdisciplinary projects that aim to contribute toward (more) sustainable development.  相似文献   

19.
NutrientcyclingcharacteristicsofQuercusacutisimaandPinusmasonianamixedforestintheThreGorgeReservoirarea,ChinaWuGangDepartmen...  相似文献   

20.
In accordance with principle sand methods of ecology, this paper studied the effects of acidic deposition on productivity and volume increment of masson pine and Cinnamomum campora forest which are widely distributed in southern suburbs of Chongqing. Based on the field data and measurements, a multivariable stepwise regression model was established to analyze the effects of multiple environmental factors on the productivity of the forest ecosystems. This model was used to assess the volume and economic losses of these two forest ecosystems caused by acidic deposition. The results showed that, among the environmental factors, pH value of precipitation, soil depth, soil organic contents and slope are the dominant ones influencing the growth of masson pine forest. It is also shown that the acidic deposition has no clear relation to the growth of C.Campora forest, so development of such broad-leaved forest is suitable in the area.  相似文献   

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