德庆县水土流失区沙渍地开发利用研究

德庆县水土流失区沙渍地开发利用研究沈家安（广东省德庆县水土保持办公室，５２６６００）沙渍地是德庆县花岗岩崩岗侵蚀的产物。崩岗侵蚀带来大量泥沙，冲入谷地覆盖农田，形成高低不平的沙渍地。在治理水土流失的同时，如何开发利用沙渍地，发展各项生产，增加经济收入...     

隔坡沟状梯田的修建技术及效益

隔坡沟状梯田的修建技术及效益于宗周，张金柱，郭素萍，李保国（河北林学院，保定市０７１０６０）河北省太行低山片麻岩区石厚土薄，人多耕地少。人均耕地仅０．０４ｈｍ２，而人均山场达０．４７ｈｍ２，发展山区经济，实现脱贫致富的出路在于开发利用广阔的山场。但长...     

Principal component analysis and discriminant analysis (PCA-DA) for discriminating profiles of terminal restriction fragment length polymorphism (T-RFLP) in soil bacterial communities

To assess the impact of a transgenic crop on soil environment, we compared soil bacterial communities from the rhizospheres of cucumber green mottle mosaic virus (CGMMV)-resistant transgenic watermelon (Citrullus vulgaris [Twinser] cv. Gongdae) and non-transgenic parental line watermelon at an experimental farm in Miryang, Korea. Soil microbial community structure was studied using terminal restriction fragment length polymorphism (T-RFLP) using HaeIII and HhaI enzymes on products from polymerase chain amplification reactions (PCR) of total DNA from rhizosphere. We used principal component analyses (PCA) to reduce dimensionality of T-RFLP profiles before comparison. On these PCA scores, we conducted discrimination analyses to compare soil microbial communities from the rhizosphere of transgenic and non-transgenic. Discriminant analyses indicate that microbial communities from rhizosphere of transgenic and non-transgenic watermelon did not differ with significance at 95% level. Our study could be used as a model case to assess the environmental risk assessment of transgenic crops on soil microbial organisms.     

Demography and conservation of the Tristan albatross Diomedea [exulans] dabbenena

The Tristan albatross Diomedea [exulans] dabbenena is the third rarest albatross species, with a breeding population of around 1500 pairs almost totally restricted to Gough Island in the Tristan da Cunha group, central South Atlantic. During January 2000, the entire breeding population of Gough was surveyed for the first time since 1956, and 2400 incubating pairs were counted. An analysis of the areas that are likely to have been surveyed most accurately in the past suggests that the population has decreased by around 28% over 46 years. The number of large chicks counted over three successive seasons (1999-2001) was highly variable (range 318-1129). The average count over this period (705 chicks) is less than counts made in 1979 (792) and 1982 (798). A total of 656 chicks were counted in September 2001, giving an island breeding success of just 27.3%. However, breeding success varied considerably in different areas of the island, ranging from 17.6 to 68.0%. During the 2001 season most breeding failures were of large chicks, and over 4 years where data were available, 75% of breeding failures occurred during the chick period. Predation by introduced house mice Mus musculus is the most likely cause of chick mortality. In a small study population, birds began breeding at an average age of 9.7 years and annual adult survival from 1985 to 2001 was 92.6% (SE=1.6%). Both breeding success and adult survival estimates are low in comparison with other Diomedea species and population modelling predicts a population decreasing at an annual rate of 2.9-5.3%. Further research is needed urgently to assess whether breeding success is typical, and to confirm that mouse predation is the cause of chick mortality. The low productivity of this species will compound the negative impacts of longline fishing mortality, which are likely to be reducing adult and juvenile survival.     

新型除草剂丙酯草醚的微量合成

从苯酚、对氨基苯甲酸和2-甲硫基-4,6-二氯嘧啶出发,建立了包含取代、氧化和缩合等7步反应的丙酯草醚除草剂微量制备方法。最终产物经制备HPLC纯化,其收率为53%,化学纯度大于98%,用MS(EI)、HPLC-MS1、H-NMR、UV等方法确认了丙酯草醚的结构。所建立的丙酯草醚微量制备方法,为放射性同位素标记丙酯草醚的合成奠定了基础。     

拍卖“五荒”（未治理小流域）使用权，加快水土流失防治管理办法

拍卖“五荒”（未治理小流域）使用权，加快水土流失防治管理办法（试行）根据《中华人民共和国水土保持法》第二十六条和《中华人民共和国水土保持法实施条例》第十八条规定，总结各地的经验，为指导和推动拍卖“五荒”（指荒山、荒坡、荒沟、荒滩、荒水，统称未治理小流...     

坚持治理与开发相结合变重点防治区为经济开发区

坚持治理与开发相结合变重点防治区为经济开发区龚少杰（陕西省略阳县水电局，７２４３００）贺清明，孙栓科（陕西省略阳县水土保持工作站）陕西省略阳县自１９８９年被国家列为长江上游水土保持重点防治区后，坚持“预防为主”方针，大搞治理开发，以建设基本农田促退耕...     

成绩显著 任重道远─—记我国水土保持45年

中华人民共和国成立４５年来，水土保持工作在探索中前进，在改革中发展，取得了显著的成绩，积累了丰富的经验，共完成综合治理面积５８万ｋｍ２，其中兴修梯田８１０．８万ｈｍ２，建沟坝地１８９．２万ｈｍ２，营造水土保持林３１２６．７万ｈｍ２，栽植经济林果２０８万ｈｍ２，种草３４０万ｈｍ２。通过综合治理，不仅保持了水土，减少了土壤侵蚀，而且发展了农林牧副加各业生产。目前全国已有１５个省（区、市）、８０个地级单位、５００多个县级单位建立了监督执法机构，专兼职水保监督检查员２．４万人，农民管护员１０万人，全国开展监督执法的试点县有３５０多个，其中１００个试点县己验收合格。防治水土流失，是一项长期的战略任务，需要几代人坚持不懈地艰苦奋斗，才能达到预定的目标。     

从彩红外航片上分析南川河流域土壤侵蚀状况

从彩红外航片上分析南川河流域土壤侵蚀状况费健雄，郭立民（山西省农业遥感应用研究所，太原０３０００２）从彩红外航片上分析流域黄土区土壤侵蚀状况，主要是根据航片上显示的沟缘线分布高低，沟谷地、沟坡面积比例大小，沟坡上侵蚀沟的密度、规模、侵蚀方式，沟坡地表...     

[A环-U-~(14)C]丙酯草醚在土壤中的迁移和淋溶

在实验室模拟条件下,采用同位素成像及液体闪烁测量技术对[A环-U-14C]丙酯草醚在7种土壤中的迁移和淋溶特性进行了研究。结果显示:[A环-U1-4C]丙酯草醚在7种土壤(S1~S7)薄板层析中的Rf值分别为0.36、0.27、0.21、0.31、0.30、0.15和0.24,这表明丙酯草醚在S1中属于中等移动农药,而在其余6种土壤中均属于不易移动农药。结果还表明,[A环-U1-4C]丙酯草醚在7种土壤中随水(最大降雨量200mm/24h)的淋溶性较弱,在S1和S4中其主要分布在0~6cm土层,其余5种土壤中则主要分布在0~4cm土层。丙酯草醚在7种供试土壤中的最大淋溶量峰值均出现在0~2cm表层。因此,从迁移和淋溶特性看,田间使用丙酯草醚不易对地下水造成污染。