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21.
One of the most important endemic tree species of Chile and at the same time one of the most endangered ones is Araucaria araucana (Mol.) C. Koch, the monkey‐puzzle tree. It grows in the Andes Mountains, homeland of the indigenous Mapuche Pewenche people who depend on this tree. This paper is based on field research that investigated the ecological knowledge, uses and management of the Araucaria araucana forest by indigenous Mapuche Pewenche people based on the socio‐cultural, spiritual and ecological relationships they have with the Araucaria forest, to find out how indigenous people and their knowledge could contribute to sustainable Araucaria forest management. A Mapuche Pewenche community located in the IX region of Chile contributed to this study. Based on the analyses this paper illustrates the nature of indigenous ecological knowledge of Araucaria araucana on the one hand, and its utility in native forest management on the other. The research shows that the Mapuche Pewenche hold ecological knowledge and conduct practices to manage their Araucaria forest in a balanced way. They conserve and use forest biodiversity at one and the same time. This paper provides recommendations for sustainable Araucaria forest management and conservation strategies ex‐situ and in‐situ incorporating indigenous knowledge and scientific knowledge and for promoting a collaborative natural resources management.  相似文献   
22.
Mitigation and offset programs designed to compensate for ecosystem function losses due to development must balance losses from affected ecosystems with gains in restored ecosystems. Aggregation rules applied to ecosystem functions to assess site equivalence are based on implicit assumptions about the substitutability of functions among sites and can profoundly influence the distribution of restored ecosystem functions on the landscape. We investigated the consequences of rules applied to the aggregation of ecosystem functions for wetland offsets in the Beaverhill watershed in Alberta, Canada. We considered the fate of 3 ecosystem functions: hydrology, water purification, and biodiversity. We set up an affect‐and‐offset algorithm to simulate the effect of aggregation rules on ecosystem function for wetland offsets. Cobenefits and trade‐offs among functions and the constraints posed by the quantity and quality of restorable sites resulted in a redistribution of functions between affected and offset wetlands. Hydrology and water purification functions were positively correlated with one another and negatively correlated with biodiversity function. Weighted‐average rules did not replace functions in proportion to their weights. Rules prioritizing biodiversity function led to more monofunctional wetlands and landscapes. The minimum rule, for which the wetland score was equal to the worst performing function, promoted multifunctional wetlands and landscapes. The maximum rule, for which the wetland score was equal to the best performing function, promoted monofunctional wetlands and multifunctional landscapes. Because of implicit trade‐offs among ecosystem functions, no‐net‐loss objectives for multiple functions should be constructed within a landscape context. Based on our results, we suggest criteria for the design of aggregation rules for no net loss of ecosystem functions within a landscape context include the concepts of substitutability, cobenefits and trade‐offs, landscape constraints, heterogeneity, and the precautionary principle.  相似文献   
23.
Understanding human perspectives is critical in a range of conservation contexts, for example, in overcoming conflicts or developing projects that are acceptable to relevant stakeholders. The Q methodology is a unique semiquantitative technique used to explore human perspectives. It has been applied for decades in other disciplines and recently gained traction in conservation. This paper helps researchers assess when Q is useful for a given conservation question and what its use involves. To do so, we explained the steps necessary to conduct a Q study, from the research design to the interpretation of results. We provided recommendations to minimize biases in conducting a Q study, which can affect mostly when designing the study and collecting the data. We conducted a structured literature review of 52 studies to examine in what empirical conservation contexts Q has been used. Most studies were subnational or national cases, but some also address multinational or global questions. We found that Q has been applied to 4 broad types of conservation goals: addressing conflict, devising management alternatives, understanding policy acceptability, and critically reflecting on the values that implicitly influence research and practice. Through these applications, researchers found hidden views, understood opinions in depth and discovered points of consensus that facilitated unlocking difficult disagreements. The Q methodology has a clear procedure but is also flexible, allowing researchers explore long‐term views, or views about items other than statements, such as landscape images. We also found some inconsistencies in applying and, mainly, in reporting Q studies, whereby it was not possible to fully understand how the research was conducted or why some atypical research decisions had been taken in some studies. Accordingly, we suggest a reporting checklist.  相似文献   
24.
Abundance estimates are essential for assessing the viability of populations and the risks posed by alternative management actions. An effort to estimate abundance via a repeated mark‐recapture experiment may fail to recapture marked individuals. We devised a method for obtaining lower bounds on abundance in the absence of recaptures for both panmictic and spatially structured populations. The method assumes few enough recaptures were expected to be missed by random chance. The upper Bayesian credible limit on expected recaptures allows probabilistic statements about the minimum number of individuals present in the population. We applied this method to data from a 12‐year survey of pallid sturgeon (Scaphirhynchus albus) in the lower and middle Mississippi River (U.S.A.). None of the 241 individuals marked was recaptured in the survey. After accounting for survival and movement, our model‐averaged estimate of the total abundance of pallid sturgeon ≥3 years old in the study area had a 1%, 5%, or 25% chance of being <4,600, 7,000, or 15,000, respectively. When we assumed fish were distributed in proportion to survey catch per unit effort, the farthest downstream reach in the survey hosted at least 4.5–15 fish per river kilometer (rkm), whereas the remainder of the reaches in the lower and middle Mississippi River hosted at least 2.6–8.5 fish/rkm for all model variations examined. The lower Mississippi River had an average density of pallid sturgeon ≥3 years old of at least 3.0–9.8 fish/rkm. The choice of Bayesian prior was the largest source of uncertainty we considered but did not alter the order of magnitude of lower bounds. Nil‐recapture estimates of abundance are highly uncertain and require careful communication but can deliver insights from experiments that might otherwise be considered a failure.  相似文献   
25.
The discount rate for cost-benefit analysis has to take account of future scarcity of ecosystem services in consumption and production. Previous literature focuses on the first aspect and shows the importance of the relative price effect, for given growth rates of consumption and ecosystem services. This paper focuses on intermediate ecosystem services in production and shows that for limited substitutability and a low growth rate of these ecosystem services, the growth rate of consumption, and thus the discount rate, declines towards a low value. Using a Ramsey growth model, the paper distinguishes three cases. If ecosystem services can be easily substituted, the discount rate converges to the usual value in the long term. Secondly, if ecosystem services can be easily substituted in production but not in consumption, the relative price effect is important. Finally, and most interestingly, if ecosystem services cannot be easily substituted in production, the discount rate declines towards a low value and the relative price effect is less important. Another part of the previous literature has shown that a declining discount rate is the result of introducing several forms of uncertainty, but this paper reaches that conclusion from an endogenous effect on the growth rate of the economy.  相似文献   
26.
为了判别不同溶解氧条件下脱氮效果和碳的需求量,在水温为25~30℃条件下,设置了缺氧、微氧和有氧3种输入条件,以及C/N分别为2.0、1.5两种碳源投放量开展实验。研究表明:溶解氧的存在对反硝化作用的启动有延迟作用,但影响较小。溶解氧对于反硝化过程并没有产生明显的抑制作用,但在溶解氧较低的情况下,反硝化速率更为理想。缺氧条件下,C/N的适宜值应低于1.5;微氧条件下的C/N适宜值在1.5~2.0;而在有氧条件下C/N=2.0时可高效去除硝酸盐。该研究可为农村地区家庭自行去除饮用水中硝酸盐的实际应用提供参考。  相似文献   
27.
九龙江口滨海湿地生源要素空间分布特征   总被引:8,自引:3,他引:5  
余小青  杨军  刘乐冕  田原  余正  王昌付 《环境科学》2012,33(11):3739-3747
为了揭示亚热带典型滨海湿地生源要素的空间分布特征及影响因素,选取九龙江口滨海湿地为研究对象,于2009年夏采集表层沉积物及柱状样,利用元素分析仪和流动注射分析仪对主要生源要素碳、氮、磷、硫(C、N、P、S)进行分析.结果表明,九龙江口滨海湿地生源要素含量较高,总碳、总氮、总磷、总硫(TC、TN、TP、TS)的均值分别为(12.64±2.66)、(1.57±0.29)、(0.48±0.06)、(2.61±1.37)g·kg-1,空间分布差异性显著.红树林植被区表层沉积物的TC、TN、TP含量高于米草植被及光滩,高潮位TC、TN、TP含量>中潮位>低潮位,TS在米草植被及中潮位含量较高.柱状样的TC、TN具有相似的垂直变化趋势,均表现为由表层向下逐渐降低,且不同植被间的柱状样TC、TN含量在同一深度上都表现为:红树区>米草区>光滩区;柱状样TP平均值是光滩最低,TS平均值是光滩最高.冗余分析表明,植被类型、pH及潮位是影响表层沉积物生源要素(C、N、P、S)分布最显著的环境因子,解释量分别为24.0%、19.0%和11.6%.  相似文献   
28.
Problems related with industrials effluents can be divided in two parts: (1) their toxicity associated to their chemical content which should be removed before discharging the wastewater into the receptor media; (2) and the second part is linked to the difficulties of pollution characterisation and monitoring caused by the complexity of these matrixes. This investigation deals with these two aspects, an electrochemical treatment method of an olive mill wastewater (OMW) under platinized expanded titanium electrodes using a modified Grignard reactor for toxicity removal as well as the exploration of the use of some specific analytical tools to monitor effluent phenolic compounds elimination. The results showed that electrochemical oxidation is able to remove/mitigate the OMW pollution. Indeed, 87% of OMW color was removed and all aromatic compounds were disappeared from the solution by anodic oxidation. Moreover, 55% of the chemical oxygen demand (COD) and the total organic carbon (TOC) were reduced. On the other hand, UV- Visible spectrophotometry, Gaz chromatography/mass spectrometry, cyclic voltammetry and 13 C Nuclear Magnetic Resonance (NMR) showed that the used treatment seems efficaciously to eliminate phenolic compounds from OMW. It was concluded that electrochemical oxidation in a modified Grignard reactor is a promising process for the destruction of all phenolic compounds present in OMW. Among the monitoring analytical tools applied, cyclic voltammetry and 13 C NMR are among the techniques that are introduced for the first time to control the advancement of the OMW treatment and gave a close insight on polyphenols disappearance.  相似文献   
29.
王晓玲  尹军  李术宽  韦新东  高尚 《环境科学》2011,32(11):3412-3418
基于ASM2d模型建立了稳定运行的MUCT工艺营养物质去除过程的动力学反应模型,比较各种COD、TN、NH 4+-N、TP的实测值和模拟值,以确定系统在低C/N条件下运行时的动力学和化学计量学参数.模拟结果表明,稳态模型中的动力学参数qPHA、KA、KPP、YPO3-4、μAUT和ηNO-3分别取值2.90 g.(g.d)-1、3.85 g.m-3、1.35 g.(g.d)-1、0.35、1.6和0.8.其他的动力学和化学计量学参数可采用IWA给出的默认值.  相似文献   
30.
参考美国核管制委员会(NRC)的行业规范RG 1.180,对比研究该规范中涵盖的两大标准体系,并以射频辐射抗扰度试验作为切入点,深入探讨了MIL-STD与IEC标准在干扰信号特性、试验布局、测试方法以及结果评价等关键技术上的差异。举例说明了具体测试中的技术细节以及试验结果的评估和使用方法。最终,形成试验实施的指导建议,为核电设备电磁兼容试验提供技术支持,并最终实现核电站的安全目标。  相似文献   
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