全国水土保持生态修复类型区治理措施研究

在全国生态修复分区的基础上,根据各区的自然条件、社会经济状况、水土流失特点和经济发展方向,结合近年来生态修复试点、示范工程实施情况,提出了生态修复的不同模式和分区治理对策.这些治理对策将有助于全国各级水土保持生态修复规划及实施.可实行分类指导,减少水土流失,加速退化生态系统的修复.     

淮河流域伏牛山区水土保持生态自然修复适宜性评价与分区

伏牛山区水土流失危害严重,实施水土保持生态修复是加快区域水土流失防治步伐的有效措施。针对大区域生态修复工程建设亟待解决的适宜性区划问题,采用主导因子分级组合及其专题图叠加分析法,对伏牛山区生态自然修复的适宜性进行评价与分区。1)提出地貌类型、土地覆被类型和地面坡度3个主导因子作为生态自然修复适宜性评价与分区指标,并对其进行分级(分类)和分区;2)按照实施封禁保育(促进生态自然修复)措施的适宜程度,提出"适宜"、"暂不适宜"和"不适宜"3个生态自然修复适宜性等级,并确定其区域分布格局;3)将伏牛山区的生态自然修复适宜性划分为2个大区(一级区)、4个亚区(二级区)和15个类型区(三级区)。研究结果可为伏牛山区水土保持生态自然修复工程的规划布局提供技术支撑。     

全国水土保持生态恢复分区探讨

把年降水量和干燥度作为判断生态自然恢复难易程度和生态恢复分区的基本依据 ,将全国划分为 4个水土保持生态恢复一级类型区 ;按照区内相似性和区间差异性 ,根据水土流失、地貌、土壤等情况 ,在一级类型区中可划分若干个二级类型区。根据各类型区的特点 ,提出了相应的生态恢复措施。     

沂蒙山区水土保持生态修复适宜性等级评价及分区

以淮河流域沂蒙山区为例,基于生态修复的内涵和狭义水土保持生态修复概念的界定,在分析研究区自然及社会经济状况的基础上,选取海拔、土地利用类型、地面坡度3个因子为基本指标,选取土壤侵蚀强度因子为辅助指标,采用主导因子分级组合法构建了由27种组合类型组成的生态修复适宜性评价等级区域单元体系,将研究区的生态修复适宜性划分为适宜、暂不适宜、不适宜3个等级。进行生态修复适宜性分区,将研究区划分为2个一级区、4个二级区和13个类型区,并结合遥感资料和实地调查结果绘制了生态修复适宜性类型区空间分布图。     

桐柏大别山区水土保持生态修复适宜性评价与分区

针对大区域生态修复工程建设亟待解决的生态修复适宜性区划问题,采用主导因子分级组合法及其专题图叠加分析法,对淮河流域桐柏大别山区生态修复的适宜性进行了评价与分区研究。(1)用地貌类型(海拔高度)、土地覆被类型和地面坡度3个主导因子构建了生态修复适宜性评价与分区指标体系,并对指标因子进行了分类(或分级)和区域划分;(2)按照实施封禁保育(促进生态自我恢复)措施的适宜程度,提出了"适宜"、"暂不适宜"和"不适宜"3个生态修复适宜性等级,评价和确定了不同区域的生态修复适宜性;(3)按照生态修复适宜性将桐柏大别山区划分为2个生态修复区、4个亚区和16个类型区,可为在桐柏大别山区全面开展水土保持生态修复工程提供科学依据及技术支撑。     

对甘肃省开展水土保持生态修复的认识和思考

甘肃省有2个县被列入2002年全国第二批水土保持生态修复试点,通过项目的实施取得以下几点认识与思考:一是进行水土保持生态修复分区研究,作好生态修复规划;二是贯彻人与自然和谐相处的思想,切实解决好群众的生产生活问题;三是科学配置修复措施,标本兼治,确保生态修复有效推进;四是政府推动,扩大协作,整合项目,提高生态修复实施效果。     

福建省水土保持生态修复探讨

山地丘陵为主的地形,再加上侵蚀力强的水力和抗蚀力弱的母质和土壤,使福建省生态环境相当脆弱,水土流失潜在危险大。另一方面,丰富的水热资源则为生态修复提供了良好的基础。作者从福建省实际出发,提出以水土流失作为主导因子,根据一定的分区原则将全省划分为五大生态修复类型区,同时利用GIS的空间分析功能,将水土保持生态修复类型区与水土流失因子、坡度等自然因子和人口密度等社会经济因子进行叠加运算,分析各区的特点,并根据各区特点,提出了相应的生态修复方向和采取的水土保持生态修复措施。     

福建省水土保持生态修复探讨

山地丘陵为主的地形,再加上侵蚀力强的水力和抗蚀力弱的母质和土壤,使福建省生态环境相当脆弱,水土流失潜在危险大。另一方面,丰富的水热资源则为生态修复提供了良好的基础。作者从福建省实际出发,提出以水土流失作为主导因子,根据一定的分区原则将全省划分为五大生态修复类型区,同时利用GIS的空间分析功能,将水土保持生态修复类型区与水土流失因子、坡度等自然因子和人口密度等社会经济因子进行叠加运算,分析各区的特点,并根据各区特点,提出了相应的生态修复方向和采取的水土保持生态修复措施。     

浙江省水土保持生态修复分区与重点探讨

浙江省具有良好的实施水土保持生态修复的自然条件和社会经济条件。根据地形地貌、年降水量和人口密度,将全省划分为浙西、浙南、浙中山地丘陵区、浙北平原区和浙东沿海平原及岛屿区三个水土保持生态修复分区,并提出了各分区生态修复的重点。     

平凉市水土保持生态修复分区措施配置及修复效果研究

以陇东黄土高塬沟壑区平凉市水土保持生态修复分区结果为依据,研究了平凉市不同水土保持生态修复分区的措施配置、投资规模、投资构成、修复因子与修复效果,对类似地区水土保持生态修复实践具有一定的指导和借鉴意义。     

低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响

【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。     

Biodiversity and ecogeography of wild Lactuca spp. in some European countries

Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions.     

Pasture Vegetation Elemental Analysis by Laser-Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing.     

Properties of anaerobically digested and composted municipal solid waste assessed by linking soil mesofauna dynamics and nitrogen modelling

We have studied the effect of anaerobically digested (ADMSW) and composted municipal solid waste (CMSW) on mineralization and foodweb dynamics to verify the hypothesis that ADMSW would immobilize N right after addition to soil in contrast to addition with CMSW. Another hypothesis was that the mesofauna (enchytraeids and microarthropods) would stimulate N release from the decomposer community. We measured excretion of -N and urea-N from the mesofauna and hypothesized that enchytraeids would release urea. ADMSW and CMSW were amended to pots with sandy loam and barley. The pots were divided into treatments with or without mesofauna. Mesofauna, plant N and biomass, soil N and ergosterol (fungal biomass) were measured over a 113-day period of four equidistant samplings. Soil respiration, N mineralization and N release by the mesofauna were modelled from concurrent studies. ADMSW- and CMSW-treated soils initially (<20 days) immobilized N. The amendments did not increase plant growth substantially, and this was probably due to N-limitation in the early stages of plant growth. Enchytraeid abundance was about three times higher in ADMSW- than CMSW-treated soils, indicating that ADMSW contained more labile compounds, bacteria, and microfauna. The mesofauna did not affect N-content, but the cumulated -N excreted by the mesofauna was estimated to be substantial and about one-fifth of total plant N in ADMSW. An explanation for this discrepancy might be that in the absence of the mesofauna, other members of the detrivore and microbivore community performed the mesofauna’s function. Neither enchytraeids nor microarthropods excreted urea.     

Faculty positions: Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Faculty positions: Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Faculty positions:Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Assessing the effectiveness of conservation measures: Resolving the “wicked” problem of the Steller sea lion

“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options.     

Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage

Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate.     

Macroinvertebrates in North American tallgrass prairie soils: effects of fire, mowing, and fertilization on density and biomass

The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils.