于都县水土保持成效与做法

20 0 0年于都县水土流失面积 8 8万hm2 ,比列入重点治理以前的 1990年减少 2 2万hm2 ;农民人均纯收入比1990年净增 1347元。该县的主要做法是加大宣传力度 ,营造水保氛围 ;开展崩岗治理 ,攻克治理难点 ;发展水保产业 ,实现生态、社会、经济效益的统一 ;开展监督管理规范化建设 ,切实保护治理成果。     

明确任务 加快水土保持生态建设步伐

1998年以来内蒙古自治区生态建设以每年造林 3 3 3 3万hm2 、治理水土流失面积 43 3 3万hm2 的速度推进。至 2 0 0 0年底全区黄河流域 (片 )累计治理水土流失面积 2 5 6万km2 。“十五”期间 ,全区将治理沙漠化土地 666 67万hm2 ,治理水土流失面积 166 67万hm2 。提出了“十五”期间水土保持生态环境建设的主要措施     

赣县精品小流域建设成效与经验

江西省赣县以建设精品小流域为突破口,治理与开发结合,实施与管理并重,通过规模治理、综合治理,有效地改善了生态环境,推动了县域经济快速、持续、协调发展。截至2004年底,全县建成精品小流域13条,完成水土流失综合治理面积14 623.24 hm2。与1997年相比,项目区年增加蓄水量0.47亿m3,新增和改善农田有效灌溉面积1 086.6hm2;年土壤流失量下降了74.05万t,保土减沙效率达77.13%;人均产粮由344 kg增加到440 kg,人均纯收入由1 084元增加到2 081元。     

呼斯太河流域水土保持世行贷款项目效益分析

呼斯太河流域水土保持世行贷款项目实施期为 8年 ( 1994～ 2 0 0 1年 ) ,总投资 85 0 0万元 ,将完成新增治理水土流失面积 2 0 2 7km2 。截至 1999年底 ,6年共完成治理面积 2 3 5km2 ,提前超额完成了任务 ,项目区水土流失治理程度由2 4%提高到 72 9%,土地利用率由 3 2 %提高到 82 0 %,植被覆盖度由 2 5 %提高到 72 %,土地生产力由 1741元 /hm2 增加到 3 75 0元 /hm2 ,人均收入由 62 8元增加到 2 485元 ,已显示出显著的经济、生态、社会效益     

甘肃省水土保持小流域生态系统建设研究

1991～ 2 0 0 0年甘肃省开展了水土保持小流域生态系统建设研究 ,对全省不同水土流失类型区 10 3条小流域从治理方略、规划设计、生态建设、效益开发、经营管护等方面进行了系统的试验和探索 ,取得了显著成效。平均治理程度由 3 8 86%提高到 77 70 % ;农、林、牧用地比例由基期的 43 17∶12 5 8∶4 5 0调整为 3 8 5 3∶2 9 0 5∶14 19;年人均纯收入由3 82 87元增长到 110 6 3 5元 ;推广应用面积达到了 73 11km2 。     

世行贷款昕水河流域水土保持项目建设评价

世行贷款昕水河流域水土保持综合治理项目自 1994年正式启动以来 ,共完成投资 180 3 9 5 7万元 ,治理水土流失面积 3 2 63 9 94hm2 。通过 8年的建设 ,项目区年人均社会总产值由 64 6元上升到 3 884 4元 ,增长 5倍 ;年人均纯收入由 3 91 6元上升到 12 43 81元 ,增长 2 2倍 ;土地利用率由 5 1%提高到 5 6 6%,土地利用结构趋于合理。项目区植被覆盖率由 3 0 6%提高到 3 7 7%,治理度达到 46 1%。     

以法为盾 保护水土 全面推进黑龙江省水土保持生态建设

黑龙江省水土流失严重 ,水土流失面积占全省总面积的 2 9 8% ,年土壤侵蚀总量达 2亿多t。到 2 0 0 0年底 ,累计审批水土保持方案 870 0件 ,收缴水土流失防治费近 2 819万元 ,收罚没款 181 2万元。全省共治理水土流失面积32 2 80 6km2 ,转让“四荒”面积 12 0 95万hm2 (其中 6 1 4%已得到开发治理 )。近期目标是每年治理水土流失面积 2 2 0 0km2 ,到 2 0 10年重点地区的水土流失得到初步治理     

认真总结经验 不断开拓创新 全面推进“珠治”工程建设

珠江上游南北盘江石灰岩地区水土保持综合治理试点工程经过3年的实施,生态、经济、社会三大效益显著:治理区水土流失面积减少了79.2%,580 km2的石漠化土地、潜在石漠化土地得到了整治;建成了高标准综合配套的坡改梯工程7 123 hm2,新增保护耕地面积27 370 hm2,增加灌溉面积13 364 hm2,改善了农业生产基础条件,粮食总产量比治理前增加6.1%;农业总产值由治理前的13.16亿元提高到17.67亿元,农民年人均纯收入由治理前的1 076元上升到1 369元,农村贫困人口由治理前的13.74万人减少到10.02万人;促进了社会主义新农村建设,推动了社会进步。针对存在的问题,提出了切实抓好"珠治"工程建设的意见。     

宁夏水土保持生态环境建设调研报告

宁夏是全国水资源最少的省 (区 ) ,平均年降水量为 30 5mm ,耕地占有水量为 990m3/hm2 ,人均水资源量为2 2 8m3。该区水土流失严重 ,水土流失面积占总面积的 75 % ,水力侵蚀区的年土壤侵蚀模数为 10 0 0～ 10 0 0 0t/km2 。在当前水土保持生态环境建设中要重视从理论与实践的结合上 ,总结当前小流域综合治理开发的新突破。要把科学调配和合理利用地表径流 ,作为小流域综合治理开发的核心和治理措施优化配置的依据。千方百计提高小流域内已治理土地的产出率是发展小流域经济的核心     

大流域规划 小流域治理 更加扎实地推进水土保持和生态环境建设

20世纪 8 0年代初以来 ,山西省水土保持和生态建设取得了巨大成就 :林草植被覆盖率由 1 983年的 7 2 %提高到 2 0 0 3年的 1 9 9% ,新增水土流失治理保存面积 1 86万km2 ,累计治理水土流失保存面积达到 4 75万km2 ,治理度达 44 %。 2 0 0 3年减少土壤流失 1 1 1亿t,比 1 983年降低 2 4% ,其中减少入黄泥沙 0 9亿t。今后要把水土保持和生态环境建设导入“以大流域为规划单位、以小流域为治理单元”新的发展轨道。介绍了 2 0年来水保生态建设经验 ,明确了今后的奋斗目标     

首都圈典型区土地退化的原因分析

 根据野外工作,在地理信息系统和遥感技术的支持下,探讨以防止风蚀为目的的首都圈的范围及主要特征,着重分析首都圈典型地区土地退化的机制、分布状况和防治的季节。结果表明,土地退化的主要原因是近年持续干旱少雨,土地利用的强度过大,以及在干旱季节里没有适当的防护措施等。建议采用适宜于首都圈的封育和垄耕等防治措施。     

Transformation of the Bryansk Paleosol in Microdepressions in the Center of the East European Forest-Steppe during the Maximum of Valdai Glaciation and in the Holocene

Eurasian Soil Science - Recent and Late Pleistocene soils of the central forest-steppe in the East European Plain have been studied. The main objective of the work is to reveal changes in the...     

Minerals in the three-component combination of agrochernozems in the Kamennaya Steppe

Properties and mineralogy of fine fractions separated from agrochernozems forming a three-component noncontrasting soil combination in the Kamennaya Steppe have been characterized. The soil cover consists of zooturbated (Haplic Chernozems (Clayic, Aric, Pachic, Calcaric)), migrational-mycelial (Haplic Chernozems (Clayic, Aric, Pachic)), and clay-illuvial (Luvic Chernozems (Clayic, Aric, Pachic)) agrochernozems. All the soils are deeply quasi-gleyed because of periodical groundwater rise. The mineralogy of the fraction <1μm includes irregular mica–smectite interstratifications, di- and trioctahedral hydromicas, imperfect kaolinite, and magnesium–iron chlorite. The profile distribution of these minerals slightly varies depending on the subtype of spot-forming soils. A uniform distribution of clay minerals is observed in zooturbated agrochernozem; a poorly manifested eluvial–illuvial distribution of the smectite phase is observed in the clay-illuvial agrochernozem. The fractions of fine (1–5 μm) and medium (5–10 μm) silt consist of quartz, micas, potassium feldspars, plagioclases, kaolinite, and chlorite. There is no dominant mineral, because the share of each mineral is lower than 35–45%. The silt fractions differ in the quartz-to-mica ratio. The medium silt fraction contains more quartz, and the fine silt fraction contains more micas.     

Coregionalization of trace metals in the soil in the Swiss Jura

The provenance of trace metals in soil, whether from the parent material or from pollution, is rarely known with certainty, and the metals' history must usually be pieced together from fragmentary statistical information. This is particularly true in the Swiss Jura where the concentrations of several heavy metals around La Chaux de Fonds exceed the statutory recommended thresholds for safety. The topsoil of the 14.5-km² region was sampled on a square grid at 250-m intervals with additional nesting with distances of 100 m, 40 m, 16 m and 6 m. The concentrations of seven potentially toxic metals, namely Cd, Co, Cr, Cu, Ni, Pb and Zn, were measured. Their coregionalization could be represented by a linear model consisting of a nugget component plus two spherical structures with ranges of 0.2 km and 1.3 km. The short-range component dominated the variograms of Cd, Cr, Cu and Pb; the long-range component dominated those of Co and Ni; the variogram of Zn combined the two in approximately equal proportions. The coregionalization matrices contain moderate correlation among the nugget and the short-range components, notably between Cu and Pb, between Cd and Zn, and between Cr, Ni and Zn. The strongest correlations are at the long range between Co, Cr and Ni, and to a somewhat smaller degree between Zn and Co. Analysis of variance showed Co and Ni to be related to geology, and to the Argovian formation in particular. The indicator variogram of this formation has also a short-range component. The analysis also showed Cr and Cu to be related to land use (in different ways). Copper and Pb are strongly correlated to one another and distinct from the five other metals. The long-range structure is almost certainly a geological effect, whereas the one of short range probably results from both the geology and human activities.     

Tomato glycoalkaloids: role in the plant and in the diet

Tomatoes, a major food source for humans, accumulate a variety of secondary metabolites including phenolic compounds, phytoalexins, protease inhibitors, and glycoalkaloids. These metabolites protect against adverse effects of hosts of predators including fungi, bacteria, viruses, and insects. Because glycoalkaloids are reported to be involved in host-plant resistance, on the one hand, and to have a variety of pharmacological and nutritional properties in animals and humans, on the other, a need exists to develop a better understanding of the role of these compounds both in the plant and in the diet. To contribute to this effort, this integrated review presents data on the history, composition, and nutrition of tomatoes, with special focus on the assessment of the chemistry, analysis, composition, nutrition, microbiology, and pharmacology of the tomato glycoalkaloids comprising alpha-tomatine and dehydrotomatine; their content in different parts of the tomato plant, in processed tomato products, and in wild and transgenic tomatoes; their biosynthesis, inheritance, metabolism, and catabolism; plant-microbe relationships with fungi, bacteria, viruses, insects, and worms; interactions with ergosterol and cholesterol; disruption of cell membranes; tomatine-induced tomatinases, pantothenate synthetase, steroid hydroxylases, and cytokines; and inhibition of acetylcholinesterase. Also covered are tomato-human pathogen relationships and tomatine-induced lowering of plasma cholesterol and triglycerides and enhancement of the immune system. Further research needs in each of these areas are suggested. The overlapping aspects are discussed in terms of general concepts for a better understanding of the impact of tomato glycoalkaloids in the plant in general and in food in particular. Such an understanding can lead to the creation of improved tomatoes and to improved practices on the farm and in the consumption of tomatoes.     

Inferences from fluctuations in the local variogram about the assumption of stationarity in the variance

Geostatistics is commonly used to describe and predict the variation of soil properties over the landscape. However, many geostatistical methods require the assumption that our observed data are a realization of a random function which is intrinsically stationarity. Under stationarity, observations of a single realization of the random function at different positions can be treated as a form of replication. There are various ways in which a random function may breach the assumption of intrinsic stationarity and numerous geostatistical techniques have been developed that are able to cope with some forms of non-stationarity. What is currently needed is a set of diagnostic tools capable of detecting and identifying when data cannot plausibly be treated as a realization of a process which is stationary in the variance.In this paper, we propose an inferential method that can identify when stationarity in the variance cannot plausibly be assumed. The basis of our approach is to obtain a model for the random function under the assumption of intrinsic stationarity. If the global dataset can be regarded as a realization of a Gaussian process (perhaps after transformation), then the global variogram is sufficient for this purpose. By using a window-based method to locally estimate variograms, we can define some statistic of homogeneity of the sample variation of the data. This allows us to obtain a sample distribution for this statistic, under the null hypothesis of intrinsic stationarity, by generating multiple realizations of the postulation random function at the original sample points using Monte Carlo methods and recomputing the statistic for each realization. We selected as statistics the interquartile ranges of: i) the spatial dependence ratio (s), the proportion c₁ / (c₀ + c₁), ii) a distance parameter (a), which is the maximum lag over which the random function is autocorrelated for variograms like the spherical, and iii) the local variances (v; c₀ + c₁), where (c₀) is the nugget component and (c₁) the spatially structured component. We demonstrated this method using data from the large scale sampling (n = 1341 over 8248 km²) of the Florida Everglades, United States.     

20世纪陇南洪涝灾害特征分析

历史上发生的自然灾害可以作为今后防灾减灾的重要参考资料。通过整理统计历史文献资料,对陇南20世纪洪涝灾害的时空分布特征、区域差异性进行分析、灾害序列趋势持续性计算。结果表明:20世纪陇南共发生洪涝灾害33次,平均3.3年1次;中度灾害最多,为11次,特大灾害共发生3次;灾害多发生在1949年到1990年,月份主要集中在6、7月,连年洪涝灾害也有发生;本区内的西和为高发区,礼县、两当、武都次之;徽县、成县最少。R/S分析法计算结果表明陇南市洪涝灾害时间序列具有长期相关的特征,未来有增加的趋势。     

Accumulation of chemical elements in the raised peatbogs of the subtaiga Trans-Urals in the Holocene

The results of studying the variability of the geochemical parameters of the layers of the Sartamskii upland peatbog in the south of Tyumen oblast based on the radiocarbon time scale are given. Four basic types of peat and stages of peat deposits formation in the Holocene are distinguished: the organomineral layer of the sediments in a paleolake (up to 5065 ± 60 years ago), the low moor layer (4300–4900 years ago), the transitional layer (3100–4300 years ago), and the high moor peat (250–3100 years ago). The upper peat layer (last 200–300 years) significantly differs from its main portion; in particular, it is characterized by an increased ash content and the accumulation of a number of elements. The relationship between the various characteristics of the deposit is analyzed using principal component analysis, and the conditions of the formation of the peat deposit in different time periods are estimated, including the climatic conditions (in relative units). The anthropogenic signal of the accumulation of some elements in wetland systems is identified.     

21世纪我市可持续农业发展的耕地资源问题探讨

本阐明了耕地资源是可持续农业发展的基础，并提出利用耕地资源的对策，为农业可持续发展提供参考依据。     

Seasonal changes in the communities of microorganisms and algae in the litters of tree plantations in the steppe zone

Specific structural and dynamic parameters of communities from various ecological and trophic groups of microorganisms and algae in the litter of artificial tree stands were studied using the example of the Staro-Berdyansky Forest in the steppe zone of Ukraine. The composition of the communities was shown to vary by seasons and depend on the forest-forming woody species. In spring, in all the litters, the maximal number of actinomycetes and aminotrophs was recorded; in the leaf litter, the number of phosphate-mobilizing organisms was also the largest. In summer, the development of cellulolytic organisms, ammonifiers, and nitrogen-fixers was intensified; in autumn, the number of micromycetes and oligotrophic organisms decreased. The composition of dominants, the species richness of algae and their abundance also varied by seasons. Representatives of the Chlorophyta division predominated. The highest species richness of algae was characteristic of the spring litter samples, and their number, for the spring and autumn ones. The positive correlation was established between the numbers of micromycetes and oligotrophs, micromycetes and algae. The negative correlation was found between the numbers of micromycetes and actinomycetes, cellulose-decompose bacteria and algae in the litters.