毕节地区人口和经济因素对生态自然修复的影响

新疆南疆属于极端干旱生态脆弱带,土壤风蚀已严重制约着南疆绿洲农业的可持续发展。在分析了造成南疆绿洲区土壤风蚀主要因素的基础上,探讨了风蚀造成的危害,提出了保护、恢复与重建绿洲外缘的自然植被、加强绿洲内部防护林体系的建设、调整种植结构和进行农作物留茬覆盖等防治土壤风蚀的综合治理措施。     

新疆水土保持与可持续发展研究

新疆维吾尔自治区作为我国最大及地理位置重要的西北边陲省份，随着人口的增长区域开发进程的进一步加快，水土流失问题日趋严重，水土保持和可持续发展已成为其生态环境建设的重要课题。分析了新疆水土流失的现状、特点和成因以及存在的问题，从可持续发展角度提出了新疆水土保持的对策和建议。     

土壤和沉积物中烃类污染物的主要来源与识别标志

土壤、沉积物中烃类污染物的来源十分复杂,其输入方式主要包括矿物油直接输入、大气颗粒物沉降、通过水介质输入、工业固体废弃物、城市垃圾和生活废弃物排放及天然有机质生物化学降解产物等。不同来源的烃类污染物组成上存在一定的差别,可根据这些差别判识环境中烃类污染物的来源。介绍了不同污染源的烃类污染物中正构烷烃、类异戊间二烯烷烃、单甲基取代支链烷烃、烷基环己烷、甾萜烷烃及芳香烃类化合物的组成与分布特征,综合评述了不同污染源的分子标志物特征及主要识别标志。     

不同小麦品种千粒重对源库变化的反应

在灌溉和雨养条件下 ,研究了大粒饱满、大粒不饱满和中粒饱满三种小麦籽粒类型的千粒重对源库结构变化的反应。摘除剑叶和 1/ 2小穗数后 ,极显著减少和增加了千粒重。摘除剑叶后 ,大粒饱满的川麦 2 7和 1137的千粒重减幅较大 ,大粒不饱满的川育 14和 30 9减幅较小 ,中粒的川育 12、88凡 8等减幅也较小。去除 1/ 2小穗数后 ,川麦 2 7和 1137的千粒重增幅较少 ,川育 12、88凡 8等的千粒重增幅较多。中粒的 1189的千粒重在去除剑叶和 1/ 2小穗数后 ,增减幅度均较少。不同品种的千粒重对源库结构变化的不同反应 ,表明其灌浆的生理过程或光合器官间的相互补偿能力有差异。这种差异可能影响它们对环境胁迫的适应性。培育高产、稳产小麦品种 ,千粒重不能太大45～ 5 0 g即可 ;干旱常发的丘陵地区 ,应培育中等粒重 ,即 4 0～ 4 5 g的品种 ,以达到高产、稳产目的     

长江源头草地类型及利用意见

长江发源于被称为生命“禁区”的唐古拉山地区,海拔高,气候恶劣。本文是作者在1986年实地考察唐古拉山地区草地资源的基础上,较全面的介绍了长江源头地区的草地类型、面积、分布规律等资料,并根据该地实际提出了进一步开发利用的意见。     

茶氟概论

氟是人体必需的微量元素。茶氟具有防龋齿的保健作用,而过多摄入茶氟又会导致氟骨症,甚至引起地氟病流行。为了趋利避害,有必要综合相关研究成果,设专题对茶氟进行全面的研究。     

辽宁典型工矿区与污灌区土壤重金属污染状况及原因

对辽宁省几个典型工矿区以及污灌区土壤重金属污染状况进行调查研究,结果表明:调查区土壤重金属含量绝大多数高于土壤背景值,尤其工矿区附近土壤Cd、Pb、Cu和污灌区的Cd、Hg的污染状况应该引起足够的重视;重金属元素间存在着一定的伴生规律;土壤中重金属污染物主要来源于工矿开发、废岩、尾矿泥、大气飘尘以及污水灌溉等。     

Comparison of Soil Clean-up Standards for Trace Elements Between Countries: Why do they differ? (9 pages)

Goal, Scope and Background

In the nineteen nineties most European countries issued legislation on soil protection, including soil contamination. In the case of a presumed contamination, soil investigation mostly follows a stepwise approach starting with a preliminary investigation, then an in-depth investigation and, finally, remediation. Soil clean-up standards are often foreseen as trigger criteria to determine the need for an in-depth soil investigation or for remediation. There are however large differences in soil clean-up standards. This is partly because of the different roles of soil clean-up standards in each legislative framework and partly because of differences in the soil clean-up standard (SCS) derivation procedures. Despites these differences there are large similarities in the concepts of the derivation procedures for clean-up standards. A better understanding of the differences in clean-up standards is needed. In order to clarify the variation, the background of the clean-up standards for a selected number of countries was investigated. The objective of this paper is to investigate the underlying reason why country-wide generic soil and groundwater clean-up standards of eight trace elements (cadmium, chromium (III), copper, mercury, lead, nickel, zinc and arsenic) differ between the selected countries.

Main Features

To avoid misinterpretation of the differences in application of the clean-up standards, a short overview of the legislative role of clean-up standards is given first. Differences in model concepts and parameter values are discussed, followed by a comparison of the generic soil and groundwater clean-up standards for trace elements and a discussion on the sources of variation. The influence of the use of ecotoxicological criteria and data for the derivation of soil clean-up standards will be discussed in more detail. Selected countries were Canada, the Flemish Region (Belgium), France, Germany, Great-Britain, the Netherlands, Norway, Sweden, Switzerland and United States of America (USA).

Results and Discussion

When soil clean-up standards for eight trace elements (cadmium, chromium (III), copper, mercury, lead, nickel, zinc and arsenic) were compared between the selected countries differences of more than a factor 1000 arose. Notwithstanding the use of similar derivation procedures, differences were caused by the use of different software models with their specific input data, boundary conditions and applied protection criteria for humans and the ecology. Ecotoxicological criteria tend to lower the soil clean-up standard for the selected trace elements.

Conclusions

In the countries that are included in this study, clean-up standards are used is different ways, this is for the determination of the necessity for remediation or for the need for further soil investigation. This paper shows a wide variation in the clean-up standards, which has further implication on the decision for remediation or further investigation and, hence, the financial costs of soil management. All the clean-up standards have as primary goal the protection of human health. A number of countries also include the protection of the ecological function of the soil. Differences in selected software model, (standard) parameters values, selected human toxicological and ecotoxicological criteria, are reason for a substantial variation in the clean-up standards for trace elements.

Recommendations and Perspective

. Is this variation justified? The derivation of soil clean-up standards involves - besides scientific elements - political elements, like differentiation in landuse types (agricultural, residential, recreational, industrial), receptor at risk or protection level. It is obvious that harmonization of these elements will be complicated. However, a European action programme, like the thematic strategy for soil protection, could initiate this process of harmonization. Nevertheless, soil-clean-up standards could never be uniform over the whole of Europe because they include country specific elements (geographical, ethnological) and political decisions.     

宁夏林业生态建设固碳效应及其潜力估算

利用宁夏自治区第三次至第七次森林资源普查数据及林业生态建设工程数据,采用材积源生物量法分析研究了宁夏森林及林业生态建设工程的固碳能力和潜力。结果表明:"十五"和"十一五"林业生态建设与保护工程实施期间,宁夏自治区森林主要面积、蓄积量、森林总生物量和碳贮量等均呈增加趋势。林业生态建设与保护工程增加森林面积、天然林林分面积和人工林林分面积分别为18.30万hm2、0.88万hm2、5.76万hm2;增加活立木蓄积量、林分蓄积量分别为300.29万m3、267.48万m3,其中人工林林分蓄积量增加为207.24万m3。"十五"和"十一五"期间,宁夏林业生态建设与保护工程共增加森林碳贮量124.99万t,其中三北防护林工程、天然林保护工程和经济林工程合计增加森林碳贮量91.45万t。预计到2020年,宁夏森林总碳贮量将达到430.52万t。     

内蒙古自治区牧民收支情况分析——以锡林郭勒盟镶黄旗为例

基于对内蒙古锡林郭勒盟镶黄旗牧民家庭的入户调查数据,分析了2008、2009年西部地区牧民家庭的收入与消费结构。结果表明:牧民收入来源单一,以家畜出售为主,抗风险能力差;消费支出中饲草料购置比重最大,且增长迅速,其次是食品、教育、医疗等支出,住房方面政策补贴较多。牧民的收入与消费特点是由自然因素、市场因素、政策因素和自身因素共同决定的,基于此,提出了牧民提高收入、改善消费结构的对策建议:牧民要提高养殖技术,科学养殖,增加收入,且要转变消费观念,适度储蓄,增强抗风险能力;政府要加大对牧区的财政补贴力度,加强对牧民的教育、培训和医疗保健投入,提高牧民素质。