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51.
Respiration controls the unexpected seasonal pattern of carbon flux in an Asian tropical rain forest
Yiping Zhang Zhenghong Tan Qinghai Song Guirui Yu Xiaomin Sun 《Atmospheric environment (Oxford, England : 1994)》2010,44(32):3886-3893
Tropical rain forests play important roles in the global carbon cycle. We report a six-year eddy covariance carbon flux campaign in a primary tropical seasonal rain forest in southwest China. An unexpected seasonal pattern of net ecosystem carbon exchange was detected, with carbon lost during the rainy season and stored in the dry season. Strong seasonality of ecosystem respiration was suggested to primarily account for this seasonal pattern. The annual net uptake of CO2 by the forest varied from 0.98 to 2.35 metric tons of carbon per hectare between 2003 and 2008. 6-year averaged sink strength was 1.68 metric tons of carbon per hectare. 相似文献
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生态系统服务研究的问题与展望 总被引:1,自引:0,他引:1
生态系统服务的研究是当前资源经济学和生态经济学的研究热点之一。通过分析生态系统服务的概念辨析,认为从生态系统功能的定义过渡到生态系统服务定义的过程中,在关注生态系统整体性的同时忽略了生态系统要素之间的相互作用,导致生态系统服务的评估中可能存在着重复估值或者估值不全面等风险。针对目前的很多生态系统的评估对生态系统的耗损贬值和环境退化所造成的负效益的忽略,以及对人类活动的干扰和气候变化等对生态系统服务产生影响研究不足,提出在今后的研究中应该在深入理解生态系统的复杂生态学机制的基础上,结合数学模型模拟在不确定性下的各种风险损失,加强对生态系统服务的时空动态分析,重视在气候变化、经济发展、环境污染、城市化以及人类活动的过度放牧和过度开垦引起的水土流失、环境退化、荒漠化等土地利用变化的干扰时生态系统服务的变化和反馈,更进一步分析和预测生态系统服务的损益和响应研究;通过长期的试验监测揭示生物多样性和生态系统的关系,测度出土地利用和环境变化对生物多样性的影响和边际效益,及其对生态系统服务的影响的弹性值,实现生态系统服务的精确估值;关注生态系统服务对人类福利的影响,尤其重视贫困地区和生态脆弱区的生态系统服务对减小贫困的研究,建立科学的生态补偿机制,实现可持续发展。 相似文献
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本研究以3种钢铁厂碱渣直接法固碳技术为研究对象,该技术将钢渣进行碳酸化处理,可快速永久地将CO2固化储存在钢渣中,气固相反应可分别在高压釜、泥浆反应器和超重力旋转床的水溶液中一步完成,并将其分别定义为T1、T2、T3.通过Umberto软件建立生命周期模型,对3种技术的资源环境影响进行评估.结果表明,T1的环境影响最高,其次为T3,T2的环境影响最小.技术评价显示,T3在技术效率、资源消耗、环境影响方面具有较好的综合效益.敏感性分析表明,加热效率的敏感性系数分别为0.97、0.97和0.46.转换率与温室气体排放的关系分别呈上升、倒U型和下降的变化趋势.提高加热效率、合理利用热源及选择合适的技术效率,将有利于技术优化,减少技术的环境影响,提高固碳效率. 相似文献
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Although surface complexation models have been widely used to describe the adsorption of heavy metals, few studies have verified the feasibility of modeling the adsorption kinetics, edge, and isotherm data with one pH-independent parameter. A close inspection of the derivation process of Langmuir isothermrevealed that the equilibriumconstant derived from the Langmuir kinetic model, KS-kinetic, is theoretically equivalent to the adsorption constant in Langmuir isotherm, KS-Langmuir. The modified Langmuir kinetic model (MLK model) and modified Langmuir isothermmodel (MLImodel) incorporating pH factor were developed. The MLKmodel was employed to simulate the adsorption kinetics of Cu(II), Co(II), Cd(II), Zn(II) and Ni(II) on MnO2 at pH 3.2 or 3.3 to get the values of KS-kinetic. The adsorption edges of heavy metals could be modeled with the modified metal partitioning model (MMP model), and the values of KS-Langmuirwere obtained. The values of KS-kinetic and KS-Langmuir are very close to each other, validating that the constants obtained by these two methods are basically the same. The MMP model with KS-kinetic constants could predict the adsorption edges of heavy metals on MnO2 very well at different adsorbent/adsorbate concentrations. Moreover, the adsorption isotherms of heavy metals on MnO2 at various pH levels could be predicted reasonably well by the MLI model with the KS-kinetic constants. 相似文献
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滨海沙地木麻黄林生态系统的凋落物及其热值研究 总被引:2,自引:0,他引:2
采用定位研究的方法,在福建惠安赤湖防护林场定期收集木麻黄林分的凋落物,开展凋落物的归还量和热值的研究.结果表明,木麻黄林凋落物年归还量为14.17thm^-2 a^-1,小枝占总归还量的72.19%,其他各组分占27.81%.凋落物灰分含量:小枝4.39%~5.65%,枝条3.52%~5.65%,球果2.63%~4.23%;凋落物干重热值为:小枝20.51~21.68kJ/g,枝条19.63~20.21kJ/g,球果18.27~20.63kJ/g;凋落物去灰分热值为:小枝21.48~22.69kJ/g,枝条21.48~22.69kJ/g,球果18.91~21.49kJ/g.图1表8参26 相似文献
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废混油钻井液资源化利用技术研究 总被引:1,自引:0,他引:1
废钻井液是钻井作业中主要污染源之一,其中含有重金属、碱、盐、油、有机物等多种污染物质,特别是废混油钻井液,油含量更高,是较难解决的问题之一,也是制约油田企业环境质量提高和可持续发展的一大难题。以废钻井液处理为代表的资源化利用技术可有效治理井场废物,将处理后的废钻井液直接用来做井场围堰和平整地面的材料,既可有效地利用废物,消除污染源,又可缓解因污染引起的工农矛盾,减少由钻井开发引发的污染赔款,实现社会效益、经济效益和环境效益的统一。 相似文献