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81.
轮作方式对冬水田温室气体排放的影响 总被引:2,自引:1,他引:1
以位于西南大学农业部重庆紫色土生态环境重点野外科学观测试验站内的冬水田(RF)、水稻-油菜轮作(RR)和水稻-儿菜轮作(RV)农田为研究对象,采用静态箱-气相色谱法对农田的温室气体的排放通量进行了为期一年的原位观测,其中采用静态暗箱技术观测CH4和N2O,静态明箱技术观测CO2.结果表明,不同轮作方式下CH4的年排放总量[以CH4计,kg·hm-2]RF(422.87±27.1) RR(132.05±23.11) RV(50.91±3.83),其中RV与RR处理较RF处理CH4排放量有明显下降(P0.05);N2O的年排放总量[以N2O计,kg·hm-2]依次为RV(21.38±6.51) RR(20.02±5.23) RF(0.48±0.02),RV和RR处理N2O的排放总量均显著高于RF(P0.05);CO2的年净排放总量[以CO2计,t·hm-2]为RR(-55.43±5.04) RV(-29.1±3.00) RF(-14.08±1.81),RV和RR处理CO2的吸收量显著高于RF处理(P0.05).在100a时间尺度上,全年排放的CH4、N2O和CO2所引起综合GWP(以CO2计,t·hm-2)为RR(-46.43) RV(-22.01) RF(-2.11),表明冬水田转变为水旱轮作系统后能显著提升农田生态系统的增汇效果,相比于RV处理,RR处理增汇效果更好,即在西南地区水稻-油菜轮作农田在生态系统增汇上是一种最有效的轮作方式. 相似文献
82.
In this paper, the dynamic relationship between global surface temperature (global warming) and global carbon dioxide emission (CO2) is modelled and analyzed by causality and spectral analysis in the time domain and frequency domain, respectively. Historical data of global CO2emission and global surface temperature anomalies over 129 years from 1860–1988 are used in this study. The causal relationship between the two phenomena is first examined using the Sim and Granger causality test in the time domain after the data series are filtered by ARIMA models. The Granger causal relationship is further scrutinized and confirmed by cross-spectral and multichannel spectral analysis in the frequency domain. The evidence found from both analyses proves that there is a positive causal relationship between the two variables. The time domain analysis suggests that Granger causality exists between global surface temperature and global CO2emission. Further, CO2emission causes the change in temperature. The conclusions are further confirmed by the frequency domain analysis, which indicates that the increase in CO2emission causes climate warming because a high coherence exists between the two variables. Furthermore, it is proved that climate changes happen after an increase in CO2emission, which confirms that the increase in CO2emission does cause global warming. 相似文献
83.
M. Fehr K.A. Sousa A.F.N. Pereira L.C. Pelizer 《Environment, Development and Sustainability》2004,6(3):355-366
The research related here focuses on municipal situations where problems of sustainability may be defined and tackled on the basis of bottom-up management procedures with the participation of organized society. The aim is to build management models that may be implemented with reasonable administrative effort and cost. Implementation pursues the target of approaching a sustainable situation in the municipality. Environmental parameters for an ideal municipality with undefined geographical location are presented. For each parameter, a set of indicators is developed that can measure the prospect of sustainability. The indicators are defined in terms of numbers or literal concepts according to the possibility of measurement. Examples of management models are presented, which are able to approach the situation defined as sustainable by the indicators. The basic management tool is the learning curve of targeted communities, which is experimentally developed and applied. The indicators are grouped according to their range of applicability. 相似文献
84.
王海忠 《中国人口.资源与环境》1996,6(1):55-58
本文认为环境生态是全球可持续发展的重要组成部分,必须在全球范围内,通过有效的国际合作和国际协调来加以解决。作者认为:国际合作应在国际性河流流域管理方面发挥重要作用。对全球温室效应问题,国际组织应重视科学研究,协调各国政府在能源税收、补贴和开发再生能源方面取得进展。此外,在保护地球生物多样性方面,国际组织可调试债务与自然环境互换机制。 相似文献
85.
There are many problems in the minority regions of western Sichuan Province, such as serious soil erosion, fragile ecological environment, low levels of economy and so on. Ad-vantages of tourism resources in the "periphery regions" should be fully utilized, and "multi-tourism" meets the characteristics and present situation of the minority regions. The "multi-tourism de-velopment model" can exert the functions of tourism as the key industry. Based on the demands and the internal linkages among different industries, the model can accelerate the development of related-industries, such as eco-agriculture, eco-industry and so on. Through implementing the multi-tourism model, we can fully utilize the advantages of the periphery regions and promote the sustainable development of regional economy. 相似文献
86.
Fingerprinting Global Climate Change and Forest Management Within Rhizosphere Carbon and Nutrient Cycling Processes 总被引:2,自引:0,他引:2
As one of the two Principal Subject Editors for ESPR Subject Area 1 'Terrestrial Ecology and Biology / Soil and Sediments: Toxicology-related Subjects' (see pp 287-293), the senior author and his colleague, Dr Chen, present an example of sub-category 4 'Environmental studies of pesticides, air pollution, and management strategies for forestry and plant ecosystems'. Thereby, they inform the ESPR community about the new Australian research project concerning the fingerprints of global climate change (GCC) and forest management on rhizosphere carbon and nutrient cycling and, subsequently, present an overview on the GCC and forest management fingerprints. 相似文献
87.
全新世青藏高原东部西南季风的演变 总被引:3,自引:0,他引:3
本研究报道一组新的西南季风代用指标,即泥炭中单一种属植物———木里苔草残体纤维素和泥炭混合植物残体纤维素的δ13C时间序列,所记录的青藏高原东部全新世气候变化。两记录表明,该区全新世的下限年龄约11200aBP(14C年龄约9900aBP);从约11200aBP起该区迅速进入湿暖的全新世阶段,季风活动迅速增强;在约10800~5500aBP期间,季风总体保持在强盛状态,但其间有4次突然减弱,气候变干冷;约从5500aBP起季风活动在波动中逐渐减弱,其中有4次减弱最明显。所有这8次气候的突然变化都与北大西洋浮冰事件一一对应。这种密切的相关关系表明,西南季风强度的波动可能是对全球变化,特别是对海洋热盐环流引起的地球南北方气候波动的所谓"跷跷板效应"的响应。 相似文献
88.
89.
The current status of ecotourism in rural China was analyzed in this paper.Empirical surveys covering the whole country indicate that ecotourism in rural China has attracted a large number of tourists who,however,didn’t generate revenues that can match the number.Although the environmental quality of those rural ecotourism destinations is high with little negative impacts,several problems have already appeared,suggesting a need to monitor those areas.The current practice of interpretation in most rural ecotourism destinations did not provide environmental education opportunities to the tourists.And local communities need more effective ways to decide on the prospects of local ecotourism development by themselves.Finally,a few recommendations for improving the sustainability of ecotourism destinations were provided. 相似文献
90.
Effects of Climate and Land-Use Change on Species Abundance in a Central European Bird Community 总被引:2,自引:0,他引:2
NICOLE LEMOINE† HANS-GÜNTHER BAUER‡§ MARKUS PEINTINGER KATRIN BÖHNING-GAESE†‡‡ 《Conservation biology》2007,21(2):495-503
Abstract: Although it is known that changes in land use and climate have an impact on ecological communities, it is unclear which of these factors is currently most important. We sought to determine the influence of land-use and climate alteration on changes in the abundance of Central European birds. We examined the impact of these factors by contrasting abundance changes of birds of different breeding habitat, latitudinal distribution, and migratory behavior. We examined data from the semiquantitative Breeding Bird Atlas of Lake Constance, which borders Germany, Switzerland, and Austria. Changes in the regional abundance of the 159 coexisting bird species from 1980–1981 to 2000–2002 were influenced by all three factors. Farmland birds, species with northerly ranges, and long-distance migrants declined, and wetland birds and species with southerly ranges increased in abundance. A separate analysis of the two decades between 1980–1981 and 1990–1992 and between 1990–1992 and 2000–2002 showed that the impact of climate change increased significantly over time. Latitudinal distribution was not significant in the first decade and became the most significant predictor of abundance changes in the second decade. Although the spatial scale and temporal resolution of our study is limited, this is the first study that suggests that climate change has overtaken land-use modification in determining population trends of Central European birds. 相似文献