沾益县花山煤化工园区防护林建设探究

介绍了花山煤化工园区基本情况,从花山特殊的生态功能区,防护林建设产生的生态效益、社会效益、经济效益,防护林建设改变当地小气候,发挥多功能防护作用等方面阐述了建设沾益县花山煤化工园区防护林的必要性,并对其防护林的建设提出建议。     

福建省林权改革环境影响农户调查研究——以三明市和永安市为例

福建是全国第一个开展林权制度改革的省份。本文通过在福建省三明市和永安市实地调研的基础上,探讨福建省森林资源经营的改变对环境的影响。研究发现,林区的绝大部分林农对林权改革持满意的态度,认为林权改革前后对环境的影响有变化。数据分析显示,林改后,对林业的投入对于森林旅游的影响成正比;家庭年均收入对空气质量的影响成负相关。研究建议,继续加大对林业的投入,科学编制森林经营规划和经营方案,促进生态环境改善和林农的增收。     

Evaluation of adsorption capacities of humic acids extracted from Algerian soil on polyaniline for application to remove pollutants such as Cd(Ⅱ), Zn(Ⅱ) and Ni(Ⅱ) and characterization with cavity microelectrode

The adsorption capacities of new humic acids isolated from Yakouren forest (YHA) and Sahara (Tamenrasset: THA) soils (Algeria) and commercial humic acid (PFHA) on polyaniline emeraldine base (PEB) were studied at pH 6.6. Also the adsorption of heavy metals such as Cd2+, Zn2+ and Ni2+ on humic acid-polyaniline systems (HA-PEB) was investigated at the same conditions. HA-PEB compounds were characterized by scanning electron microscopy (SEM), infrared spectrometry and cavity microelectrode. In addition, batch adsorption and cavity microelectrode were used in the adsorption study of Cd2+, Zn2+ and Ni2+ on HA-PEB. To develop biocaptors of polluting metals using a cavity microelectrode modified by HA-PEB systems, the adsorption kinetic and adsorption capacity were investigated. The SEM analysis showed that the presence of humic acid affected the PEB surface and caused the formation of a granular morphology. The maximum adsorption capacities (qmax) of PFHA, THA and YHA determined by adsorption isotherms were 91.31, 132.1 and 151.0 mg/g, respectively. Batch adsorption results showed that qmax of Cd2+, Zn2+ and Ni2+ on HA-PEB followed the order: THA-PEB > YHA-PEB > PFHA-PEB. The voltammograms obtained with HA-PEB modified cavity microelectrode showed the appearance of new redox couples reflecting the adsorption of HA on PEB. Metal-humic acid-polyaniline voltammograms were characterized by appearance of oxidation-reduction couples or reduction wave corresponding to metal. Finally, the result may be exploited to develop a biocaptor based on the cavity microelectrode amended by THA-PEB and YHA-PEB.     

福州城市边缘区森林土壤重金属污染特征及评价

为掌握福州城市边缘区森林土壤重金属污染特征,选取10个典型区域作为研究对象,分析森林土壤中Zn、Mn、Cr、Pb、Cu 5种重金属的含量及分布特征,并采用单项污染指数和综合污染指数法对土壤进行质量评价,结果表明:Cr、Pb是该区土壤重金属污染最主要的元素;Zn、Cu、Pb、Cr含量随土层深度增加而减少,Mn则相反;Zn...     

缙云山3种典型森林降雨过程及其氮素输入

选取重庆缙云山的常绿阔叶林、毛竹林和针阔混交林为研究对象,于2012年5~10月对大气降水、穿透雨和树干径流等降水过程及其氮素输入进行研究.结果表明:①研究期间总降雨量564.88 mm,常绿阔叶林、毛竹林和针阔混交林的穿透雨量占总降雨量的比例分别为74.0%、85.0%和71.6%,且树干径流量所占比例分别为1.9%、10.3%和1.6%;3种林分的穿透雨量、树干径流量与林外降雨量之间均呈显著的线性关系(P<0.05),且穿透雨率、树干径流率与林外降雨量之间都呈对数关系(P<0.05).②与大气降水相比,穿透雨和树干径流的NO-3和NH+4浓度要高,且3种林分的大小关系为针阔混交林>常绿阔叶林>毛竹林;穿透雨和树干径流的总无机氮输入量(以N计)分别为针阔混交林(18.93 kg·hm-2)、常绿阔叶林(14.93 kg·hm-2)和毛竹林(15.31 kg·hm-2).③3种林分的无机氮输入量与穿透雨量、树干径流量之间均呈显著的线性关系(P<0.05).     

模拟氮沉降对太岳山油松林土壤呼吸的影响及其持续效应

以太岳山油松林为研究对象,对林地分别作3种凋落物处理:对照(C)、去凋(B)、去凋+切根(A),并设计了4个氮水平:对照(CK,0 kg·hm-2·a-1,以N计,下同)、低氮(LN,50 kg·hm-2·a-1)、中氮(MN,100 kg·hm-2·a-1)和高氮(HN,150 kg·hm-2·a-1),研究了土壤呼吸速率在施氮后的连续变化,以及与温度、湿度、微生物生物量C、N、土壤酶活性的关系.结果表明:去凋+切根、去凋、对照样方不同施氮水平下土壤呼吸速率基本都在施N后的第1 d处在最高峰,随即下降,切根+去凋、去凋处理样方的土壤呼吸速率在施氮后第3 d趋于稳定,而对照处理样方的土壤呼吸速率一直处于下降状态.施氮在一定程度上抑制了切根+去凋处理的土壤呼吸速率,而促进了去凋处理、对照处理的土壤呼吸速率,并且土壤微生物生物量C、N的变化与土壤呼吸速率变化一致,土壤呼吸速率与土壤酶活性、土壤湿度的拟合关系不显著(p0.05),而与土壤温度的拟合关系显著(p0.05).以土壤温度、土壤湿度构建的复合模型R s=aebTWc预测土壤呼吸的准确性高于单因子模型,施氮降低了每种凋落物处理指数关系模型(R s=aebT)的决定系数R2,并且施氮降低了切根+去凋、去凋处理的温度敏感性指数Q10,而对对照处理的Q10无明显影响.     

Forest resources and household welfare: Empirical evidence from North Central Vietnam

Using secondary data from a socio-economic quantitative household survey of the North Central region of Vietnam, the main aim of our study is to analyze the causal effect of forest resources on household income and poverty. Based on the observed characteristics of a forest-based livelihood and forest-related activities, we use a propensity score matching (PSM) method to control for potential bias arising from self-selection. The PSM results indicate that households with a forest-based livelihood had a higher level of income and lower poverty rates than did those without. Interestingly, our findings confirm that a forest-based livelihood offers much higher income than any other type of livelihood adopted by local households. Also, the poverty rate among households with a forest-based livelihood is lower than those earning non-labor income or engaged in wage/crop and crop livelihoods. Among households and provinces, we find varying opportunities deriving from forest resources, suggesting that there are potential barriers hindering local households from pursuing a forest livelihood or participating in some forest activities. Therefore, government policy and regulations on forest management should focus on improving the access of households to forest resources, while enhancing the sustainability of these resources.     

西南山地区域森林火险综合预报模型研究——以重庆市为例

森林火灾严重破坏森林生态系统的结构和功能,针对其风险预报开展研究具有重要的理论意义和应用价值。通过融合气象、地表覆盖和人类活动等要素的方式构建森林火险综合预报模型,是西南山地区域森林火险综合预报业务化应用的重要发展方向。基于《森林火险气象等级》国家标准(GB/T 36743-2018),本文研究首先构建了重庆市森林火险气象风险预报模型。然后通过融合可燃物因素和人为因素的方式,进一步构建重庆市森林火险综合预报模型。最后利用历史火点数据针对上述两类模型的精度进行对比和分析。研究结果表明:重庆市森林火灾发生次数较多,且呈现出季节性规律;重庆市森林火灾的发生不仅受到气象条件的影响,而且受到地表覆盖和人类活动等多种要素条件的共同影响;与森林火险气象风险预报结果相比,森林火险综合预报结果在空间分布上具有更高的精细程度;森林火险综合预报模型能有效提高森林火险等级预报精度。     

Mapping the Spatial Variability of Plant Diversity in a Tropical Forest: Comparison of Spatial Interpolation Methods

Knowledge of the spatial distribution of plant species is essential to conservation and forest managers in order to identify high priority areas such as vulnerable species and habitats, and designate areas for reserves, refuges and other protected areas. A reliable map of the diversity of plant species over the landscape is an invaluable tool for such purposes. In this study, the number of species, the exponent Shannon and the reciprocal Simpson indices, calculated from 141 quadrat sites sampled in a tropical forest were used to compare the performance of several spatial interpolation techniques used to prepare a map of plant diversity, starting from sample (point) data over the landscape. Means of mapped classes, inverse distance functions, kriging and co-kriging, both, applied over the entire studied landscape and also applied within vegetation classes, were the procedures compared. Significant differences in plant diversity indices between classes demonstrated the usefulness of boundaries between vegetation types, mapped through satellite image classification, in stratifying the variability of plant diversity over the landscape. These mapped classes, improved the accuracy of the interpolation methods when they were used as prior information for stratification of the area. Spatial interpolation by co-kriging performed among the poorest interpolators due to the poor correlation between the plant diversity variables and vegetation indices computed by remote sensing and used as covariables. This indicated that the latter are not suitable covariates of plant diversity indices. Finally, a within-class kriging interpolator yielded the most accurate estimates of plant diversity values. This interpolator not only provided the most accurate estimates by accounting for the indices' intra-class variability, but also provided additional useful interpretations of the structure of spatial variability of diversity values through the interpretation of their semi-variograms. This additional role was found very useful in aiding decisions in conservation planning.     

A Simulation Study to Assess the Sensitivity of a Forest Health Monitoring Network to Outbreaks of Defoliating Insects

The sensitivity of the United States Forest Health Monitoring network to outbreaks of defoliating insects was examined by means of a simulation study. A model constructed specifically for the study was used to generate a wide variety of defoliation patterns in forested landscapes. Forest configuration was that of Minnesota, USA, as expressed by the GAP land cover classification. Combinations of model parameters were based on a Latin Hypercube sample. The relationship between the average number of plots defoliated and outbreak characteristics was then examined via multiple regression. Both theoretical and model results pointed to a strong, linear relationship between the average number of plots defoliated and outbreak size. Model results provided additional insight, suggesting a significant relationship between the average number of plots defoliated and other outbreak characteristics after outbreak size was taken into account.