不同光照度下南方鲇稚鱼的摄食强度及摄食动力学

在10^3-10^-1lx光照度范围内，南方鲇稚鱼对团鲂鱼苗的摄食强度随光照度减弱而增强，在10^9lx时达最大值，随后下降，摄食率在开始摄食后10min，光照强度为10^0lx时最同，并随摄食时间延长而下降。     

运用聚类分析划分农业生态类型区

科学地划分农业生态类型区对于分类指导农业生产、合理利用农业资源具有重大的现实意义。本文通过相关分析,选择了包括自然本底、经济条件、生态环境和生态经济效益在内的26个指标,采用聚类分析的方法,把全省划分为四个生态类型区,即山区林地生态区(Ⅰ)、盆地丘陵生态区(Ⅱ)、水网平原生态区(Ⅲ)和沿海岛屿生态区(Ⅳ)。在分区的基础上,分别对各生态类型区进行了综合评述。     

浙江省找矿前景分析及需要研究解决的几个重要地质问题

简要介绍浙江省具优势的非金属矿床、偏紧缺的金属矿床的资源形势.通过对该省地质构造环境的分析,指出找矿前景.提出需要研究解决的几个重大基础地质问题及今后工作的建议.     

浙江湖州及邻区地貌与环境地质问题分析

浙江湖州及邻区地貌总体特征是以平原为主，丘陵次之，本文在讨论了影响区域地貌发育因素的基础上，对平原区和丘陵区的次级地貌单元进行了划分并作了总结。详细分析了区内不同地貌单元下存在原生和受人类经济活动影响出现的环境地质灾害问题，指出原地生质－地貌条件下区域环境地质问题（如地壳稳定性，软土地基，地下水水质，土壤渍害，水土流失等），大多数对人类社会影响不大或者已经有了相应的防治对策，但是，受人类经济活动影响，人为的或人工诱发的环境地质问题则越来越严重，如平原区由于过量开采地下水出现的地面沉降，丘陵区由于开采石矿引起的景观破坏，水土流失，岩溶塌陷和滑坡等地质灾害。     

四川土法炼磺区土壤环境化学变化初探

土法炼磺特大的“三度”排放量以及对生态环境所造成的难以逆转的毁坏,已引起社会各界的关注,但是炼磺危害区土壤环境的化学变化,却尚未曾有过专门研究。本文根据土壤样品的测定结果,探讨了四川土法炼磺区土壤环境的化学变化。结果表明:土壤PH值约降低1.1—2.4,重金属元素Cu、Zn、Cd、Pb、Ni、Mn、Fe的富集率约为30—150％,以有效态含量为标志的元素活性约增加20—55％。     

Land-cover change within and around protected areas in a biodiversity hotspot

The landscape surrounding protected areas influences their ability to maintain ecosystem functions and achieve conservation goals. As anthropogenic intensification continues, it is important to monitor land-use and land-cover change in and around protected areas. We measure land-cover change surrounding protected areas in the Maputaland-Pondoland-Albany Biodiversity hotspot from the 1980s to present. Using Landsat imagery, we classified land cover within and around each protected area. Agricultural land uses were increasing and often directly border protected area boundaries. Human settlements increased around every protected area, potentially increasing human activity along the edges of protected areas and threatening their ecological integrity. Urban expansion around protected areas varied but increased as much as 10%. Woody vegetation cover varied both within and around protected areas with possible evidence of deforestation and shrub encroachment throughout the hotspot. We recommend monitoring land cover across southeastern Africa to better understand regional trends in land-use impacts to protected areas.     

南亚热带中幼龄针阔混交林碳储量及其分配格局

以南亚热带中幼龄针阔混交林为研究对象,通过典型样地调查法,对森林生态系统各个层次进行取样调查,采用12个样地实测数据和已有生物量模型相结合的方法计算乔木层生物量,灌木层、草本层和凋落物层采用全部收获法测得其生物量,对土壤层的调查采用剖面法加土钻法,代表性样品碳含量的测定采用重铬酸钾-水合加热法。在此基础上,分析了中幼龄针阔混交林碳储量及其分配格局。结果表明,主要造林树种树根、树杆、树枝和树叶碳含量均值分别为45.07%、46.73%、46.30%和47.72%。植物碳含量表现为乔木〉灌木〉草本。乔木碳储量占植被总碳储量比例介于63.38%-94.08%之间,灌木碳储量所占比例介于3.55%-12.67%之间,而草本碳储量仅介于为1.28%-23.95%之间,不同林龄段乔木和灌木碳储量均值随林龄的增加呈上升趋势,而草本碳储量呈下降趋势。土壤碳储量介于106.73-136.61 t·hm^-2之间,土壤碳储量随林龄的增加呈现出先降低后升高的趋势。针阔混交林总碳储量介于134.79-162.60 t·hm^-2之间,分配格局表现为土壤层〉植被层〉凋落物层。土壤层碳储量所占总碳储量比例范围为78.34%-94.45%,植被层所占比例介于4.84%-20.16%之间,凋落物层仅介于0.71%-1.50%之间,中幼龄针阔混交林碳储量主要以土壤固碳为主。研究结果为树种选择、人工林生态系统固碳潜力以及人工碳汇林的经营管理等研究提供科学参考。     

Expert views on sustainability and technology implementation

The role of non-timber forest products in sustaining rural economies of the southern African region has been underestimated because of inadequate policy recognition. As a result, factors affecting the sustainability of these important resources are being undermined. The aim of the paper is to examine trade in two selected NTFPs and implications for sustaining the resource base in Zimbabwe and South Africa. In eastern Zimbabwe, baobab (Adansonia digitata) bark is harvested for craft purposes, but in danger of destruction in the short term as a result of harvesting and trade arrangements. Unless appropriate harvesting and marketing mechanisms including harvesting cycles and adaptive management are adopted, the baobabs and livelihoods of humans will be threatened in the next decade. For wood products from communal woodlands in the South African study, uncontrolled trade poses danger to sustaining the natural woodlands. In both case studies, the role of non-resident NTFP dealers is a source of inevitable threat in promoting sustainable harvesting and trade. Market forces of demand and supply factors are identified as opportunities or threats and presented in a conceptualised framework. Additionally, the NTFP sector management will need to include opportunistic improvement of small-scale agropastoralism.     

苏南丘陵区典型森林生态系统服务价值估算

针对苏南丘陵区杉木、马尾松、毛竹、栎林等4种典型森林生态系统,实测了其主要的生态系统服务功能,运用多种生态经济学方法估算了4种林分的生态服务价值。生态服务价值包括直接使用价值和间接使用价值,间接使用价值包括气体调节、涵养水源、保土固肥、防止水库淤积、营养物质循环、净化环境价值等。研究区杉木、马尾松、栎林、毛竹4种林分的生态系统服务价值中,间接经济价值分别是其直接经济服务价值的1.82、2.12、3.16、4.04倍,单位面积的森林生态系统服务价值分别为192397.30、113262.69、88350.51、103289.69元·hm-2·a-1。在区域研究中,根据地方实测的数据进行估算,能提高计量森林生态服务功能价值的精度。     

苏南丘陵地区森林土壤酶活性季节变化

研究了苏南丘陵区不同林分土壤养分、酶活性的剖面分布以及酶活性的季节动态变化特征。研究结果表明,研究区土壤偏酸性,土壤中TN质量分数较高,有机质、TK、AK质量分数中等,TP、AP质量分数较低,土壤TN、有机质、AK、AP的质量分数及蔗糖酶、脲酶、H2O2酶、磷酸酶活性随着土壤深度的增加而逐渐降低。土壤酶活性在不同季节也存在差异,蔗糖酶活性的季节变化表现为：秋季〉夏季〉春季〉冬季,脲酶活性为：夏季〉春季〉秋季〉冬季,毛竹林土壤的磷酸酶活性为：秋季〉春季〉夏季〉冬季,其它3种林分土壤的磷酸酶活性为：秋季〉夏季〉春季〉冬季,H2O2酶活性在马尾松、麻栎、毛竹林土壤内表现为：春季〉秋季〉夏季〉冬季,在杉木内林土壤内表现为：春季〉夏季〉秋季〉冬季。在α=0.01或α=0.05水平下,土壤酶活性与土壤TN、AP、AK、有机质及重元素Pb、Cu、Zn、Cr、Ni呈显著或极显著相关,与土壤容重呈显著或极显著负相关,冬季蔗糖酶与其它3个季节的蔗糖酶呈现极显著或显著正相关;秋季磷酸酶与其它3个季节的磷酸酶呈现极显著或显著正相关;夏季脲酶与其它3个季节的脲酶呈现极显著正相关;夏季H2O2酶与其它3个季节的H2O2酶呈现极显著正相关。