农林复合经营研究──桉树人工林间种西瓜对林木和土壤的效应

本文调查研究了雷州林业局纪家、河头林场桉树人工林间种西瓜对林木和土壤的影响．结果表明，利用造林前空隙种一造西瓜或在桉树林地间种西瓜，均有利于桉树生长．单位面积林木蓄积量和年生长量均比对照林分显著增加，经济效益显著；土壤养分也有增加。作为农林复合经营的有益尝试，值得在有条件的地区推广。     

Scenarios of major terrestrial ecosystems in China

The spatial pattern and mean-center shift of major terrestrial ecosystems, termed Holdridge Life Zones (HLZ), during the periods from 1961 to 1990 (T1), from 2010 to 2039 (T2), from 2040 to 2069 (T3) and from 2070 to 2099 (T4) were analyzed by combining the zonal patterns of climatic change in China and the climatic change scenarios of HadCM2 and HadCM3. The results showed that nival area would decrease rapidly with temperature increase in the future. HadCM2 and HadCM3 predicted that the nival areas might disappear in 552 years and 204 years, respectively. Using both HadCM2 and HadCM3, the five HLZ types with the largest areal extent are nival zone, cool temperate moist forest, warm temperate moist forest, subtropical moist forest and boreal wet forest, which collectively account for more than 50% of China's land mass. Among these five HLZ types, nival zone, warm temperate moist forest and boreal wet forest would decrease continuously, whereas subtropical moist forest and cool temperate forest would increase continuously during the four periods. HLZ diversity and patch connectivity would increase continuously in the 21st century. The shift distances of mean centers of HLZ types simulated using HadCM3 were markedly greater than those simulated using HadCM2, in general. The results from both HadCM2 and HadCM3 showed that boreal wet forest, subtropical moist forest, tropical dry forest, warm temperate moist forest and subtropical wet forest had bigger shift ranges, indicating that these HLZ types are more sensitive to the climatic change scenarios of HadCM2 and HadCM3.     

向海湿地河道上下游土壤重金属污染程度分析

以向海湿地河道上、下游土壤沉积物为研究对象，以Al元素作为标准化元素，通过对重金属元素富集因子的分析，研究了Cu、Ni、Mn、Fe、Ba、Cr等6种重金属元素的人为污染状况及分级。结果表明，该区土壤沉积物中重金属元素均受到不同程度的人为污染影响，部分层面Ni、Ba等重金属元素污染程度达到显著水平，造成这种现象的主要原因是富含重金属的霍林河上游矿源物质的沉积及人类对湿地开发活动的历史变迁过程；此外，径流淹没频率不同造成了两断面土壤沉积类型和沉积效果的不同，使得受水文影响较大的上游断面的人为污染程度大于受影响较小的下游断面，说明向海湿地对人为污染具有一定的缓冲能力，或向海湿地具有较强的净化和过滤功能。     

高浑浊河流悬沙质量浓度的地面遥感监测方法

以金沙江中下游一级支流龙川江为例，通过探讨河流地面反射光谱与河流悬沙质量浓度的关系，初步开发了河流悬沙质量浓度的地面遥感预测技术。研究发现，基于R800/R550的经验模型，仅能够预测浓度范围在400g．m^-3以下的悬沙质量浓度值，对于较低悬沙质量浓度的河流或其他水域有较大运用价值。光学拟合技术能够预测龙川江在其整个变化范围的河流悬沙质量浓度，最高预测浓度可以达到13000g.m^-3。通过直接运用两种方法，或者进一步将它们提升成为卫星遥感运用技术后，对于中国西南众多的江河湖库有着重要的理论和现实意义。     

A Study of Plant Species Extinction in Singapore: Lessons for the Conservation of Tropical Biodiversity

The native vascular plant flora of the Republic of Singapore has suffered the extinction of 594 out of a total 2277 species. These represent local, not global, species extinctions. Coastal habitats, including mangroves, have lost 39% of their species, while inland forests have last 29%. Epiphytic species (62% loss) appear particularly prone to extinction, which is reflected in a similar disposition exhibited by the Orchidaceae. Deforestation and disturbance have been the main cause of plant species extinction in Singapore. The rich mangrove epiphyte flora has been totally exterminated, and a number of tree species are reduced to populations of a few mature individuals. Many more species continue to survive than the species-area relationship would predict given the 99.8% loss of primary forest. This is interpreted as a result of the failure of equilibrium to be achieved yet in the remnant forest fragments, even after more than a century of isolation. Singapore's secondary forests appear to accrete plant diversity very slowly, even if contiguous with primary forest areas. We conclude that remnant fragments of primary tropical forest, even of very small size, can play a major role in the conservation of tropical biodiversity. The patterns of extinction observed in Singapore indicate that coastal and estuarine sites are in greatest demand for development and therefore must be given high priority for conservation despite their somewhat lower biodiversity. Epiphyte and orchid diversity appear to be very good indicators of the degree of disturbance suffered by a habitat in the humid tropics.     

广东省水资源问题及可持续利用对策

论述了广东省的水资源状况和水资源利用中存在的主要问题，提出了水资源可持续利用的对策。认为水质性缺水、水利工程老化失修、水资源浪费严重、管理体制不健全是水资源利用中存在的主要问题；应加强水污染的防治，健全防洪防旱体系，建立健全水资源统一管理运作饥制，提高全民节水观念，发展节水农业，走兴林治水之路，使水资源可持续利用。     

畜禽养殖区磷流失对水环境的影响及其防治措施

概述了畜禽养殖废物中磷的流失对水环境的影响,分析养殖废物中磷的来源和流失途径,并从保护水资源的角度提出减少畜禽粪便中磷流失的管理和控制措施。     

铝离子与聚硅酸的相互作用

本文应用核磁共振技术及化学分析方法研究了铝离子与聚硅酸之间的相互作用情况;借助于微电泳技术测定了含铝离子的聚硅酸絮凝剂在不同pH值条件下水解沉淀物的表面ζ电位变化情况;借助于透射电镜手段及静置观察方法考察了铝离子含量对聚硅酸胶凝作用的影响。实验结果表明,聚硅酸对铝离子具有一定的螯合(络合)和吸附作用,但二者之间不存在定量的作用关系,而是聚硅酸对铝离子的作用量随着铝离子含量的增加而增加。铝离子影响聚硅酸的胶凝时间,适量的铝离子的存在可延长聚硅酸的胶凝时间。聚硅酸的存在影响铝离子在不同pH值下的水解沉淀物的ζ电位值,使得达到零电位状态时的pH值向低pH值方向移动。     

天津市土壤风沙尘元素的分布特征和来源研究

通过与土壤标准和背景值的比较分析了天津市土壤风沙尘元素的质量分数分布特征，通过富集因子法分析了天津市风沙尘元素的富集特征，进而说明天津市风沙尘元素的来源及其变化。结果表明，（1）Cr、Ni、Cu、Zn和As质量分数均有超过土壤标准的现象。（2）Ni、Cu、Pb、Zn和Ag超过背景值10倍以上，受到了人为污染。（3）粗颗粒中西青区的Pb元素，津南区的Ni元素和Pb元素以及细颗粒中东丽区的Ca元素和Zn元素，西青区的Cu、Pb，津南区的Cr、Ni、Pb等元素达到显著污染级别；各区粗细颗粒中的Ag元素污染级别最高，有的为极强烈污染；这些元素是典型的人为污染元素。（4）粗颗粒中只有Ca和Ni污染级别有所增加，细颗粒中只有Na、Ni、As等3种元素的富集因子略有增加。所以，天津市土壤风沙尘的治理重在控制人为来源的Ni、Cu、Pb、Zn、Ag、Cr和Ca等高污染元素。     

γ-辐照对水中腐殖酸去除的研究

以腐殖酸作为消毒副产物前驱物的代表,研究了γ-辐照对其去除效果.结果表明,γ-辐照对水中腐殖酸具有较好的去除作用.腐殖酸初始浓度为10mg·l-1时,在1.0kGy的辐照剂量下,腐殖酸去除率为88.6%,总有机碳减少62.8%,色度去除率为76%.随着辐照剂量的增加,氧化还原电位先增大后减小,而电导率则相反.在相同的辐照剂量下,初始浓度较低的腐殖酸去除率较高.碳酸盐对辐照去除腐殖酸具有抑制作用,中性条件有利于γ-辐照对腐殖酸的去除.辐照去除腐殖酸的过程可用一级动力学描述.