浙江省钱塘江流域生态环境需水量研究

从浙江省钱塘江流域现有的水资源开发利用中存在的生态环境问题出发,探讨了符合钱塘江流域生态环境特点的多年平均适宜生态环境需水内涵,并在此基础上,建立了河道内多年平均适宜生态环境需水和河道外多年平均适宜生态环境需水两个部分的计算模型.模型计算结果表明,钱塘江流域多年平均河道内生态环境需水量为1.59×10~(10)m~3/a,河道外生态环境需水量为6.70×10~9m~3/a,多年适宜生态环境需水总量为2.26×10~(10)m~3/a.研究结果可为浙江省钱塘江流域的生态环境保护、水资源的可持续利用以及湿润区生态环境需水研究提供决策依据.     

径流季节变化对清水河河道生态环境需水量的影响

[目的] 估算清水河河道生态环境需水量,为保证清水河发挥其正常生态功能以及流域内水资源的合理配置提供依据。[方法] 通过对清水河流域用水情况实地调查,在分析整理多年水文统计资料的基础上,考虑生态用水安全,根据清水河径流随降水时间的季节性变化特点以及流域多年水文变化特征,在空间上选取清水河干流的不同断面计算河道生态环境需水量。针对需要满足河流不同生态功能要求,分别采用Tennant法、面积定额法,90%保证率最枯月水量法等方法计算河道基础生态需水量、蒸发需水量、输沙需水量以及水体自净需水量。[结果] 清水河河道生态环境需水量包括基础生态需水量、蒸发需水量、输沙需水量及水体自净需水量,年需水总量上游段为6.29×10⁶ m³,中游段为6.57×10⁷ m³,下游段为1.65×10⁸ m³。[结论] 清水河河道生态环境需水量与泥沙含量和水质有直接关系。泥沙含量高是清水河河道生态环境需水量高的最主要因素。     

基于层次分析法的干旱内陆河流域生态环境需水评价——以新疆台兰河流域为例

干旱内陆河流域生态环境需水综合评价是一个多层次,多目标的综合决策问题,同时是干旱区水资源合理配置与管理,生态环境保护与建设中最为关键的科学问题之一。根据台兰河流域的实际情况和环境问题,构建评价干旱内陆河流域生态环境需水状况的指标体系;该指标体系由3个层次38个评估因子组成;通过分级量化指标,用层次分析法对指标进行权重分析,提出了内陆河流域生态环境需水状况评判标准和具体的评价方法。结果显示,水资源因素对台兰河流域生态环境需水的影响最大,生态环境因素和经济社会因素次之,影响最小的是自然因素。水资源因素、生态环境因素、经济社会因素和自然因素之间相互关联,共同作用导致流域生态环境需水综合状况。评价结果与实际情况基本相符,证明层次分析方法在评价干旱内陆河流域生态环境需水状况中具有一定的应用价值。     

南水北调西线一期工程河道最小生态径流的估算与评价

南水北调西线一期工程从雅砻江支流鲜水河的达曲、泥曲和大渡河支流的色曲、杜柯河、玛柯河和阿柯河等6条河流通过“六坝七洞一渠”,将40亿m3/a水调到黄河的支流贾曲。这一水量约占引水坝址河川径流的65%~70%,剩余30%~35%的水量能否满足河道内的生态需水,需要进一步研究。本文通过分析该调水区河道内的生态需水主要是满足水生生物栖息地的需水要求,讨论了水生生物产量与水体水量之间的关系,利用河道内径流50%保证率的河道径流的30%作为最小生态径流量的方法,估算了达曲、泥曲、绰斯甲河、足木足河的水文站断面的最小生态径流量,并利用Tennant方法对估算结果进行了评价。结果表明:4~9月采用最小生态径流量可以使河道的流量状态处于中等水平,10~3月若河道内流淌着最小生态径流,可以使河道内水生生物及河道的正常功能处于非常好的状态,只要工程建成后采用计算的最小生态径流为河道内下泄流量,就可以保证同时满足调水河流的资源水和生态水。     

基于生态需水的水资源分析——以贵州省盐津河流域为例

[目的]探究中国西南湿润地区流域生态需水量计算方法,为流域水资源配置提供科学的数据参考。[方法]选择贵州省盐津河流域为研究对象,采用彭曼法、Kristensen-Jensen模型、MIKE SHE分布式水文模型(DHI)、环境功能设定法等方法从农田系统、林草系统、水生态系统计算流域最小及满意需水量,并结合水资源状况对盐津河水资源配置提出建议。[结果]盐津河总生态需水量为1.39×10~7~2.04×10~7m~3,流域内农田用水较多的是4,7和8月,林草系统不存在缺水现象,河道内枯水期及丰水期水量差距较大,可利用水量为3.84×10~7~9.17×10~7 m~3,在保证枯水期生态水量同时,取水时间主要在5—8月。[结论]河道取水应注意考虑农田作物用水规律,在预留农业用水时需要考虑作物类型及种植面积,严格遵循降雨及生态用水规律,建立蓄水设施,保证全年的生产生态用水。     

区域生态需水量计算方法研究

总结了前人的研究工作．从不同角度对生态需水进行了科学的界定；建立了不同标准下的生态需水分类体系；并按河道内与河道外生态需水的分类，给出二者详细的计算方法；以西北黄土高原地区延安市为例．分别计算了2000年来水条件下的河道内及河道外生态需水。     

基于农牧业需水特性的洋河流域农业水资源优化配置

针对洋河流域水资源短缺与水环境污染问题日益突出,以及考核断面水质难以达标等问题,为了实现水资源充分利用与环境保护的双重目标,结合流域经济社会发展及水资源开发利用现状特点,以洋河流域为研究对象,考虑水质约束,构建了农业水资源优化配置模型。在保障考核断面水质达标前提下,通过优化各月份不同作物和牲畜的配水量,以及作物种植面积和牲畜养殖数量,以实现农业经济效益最大化。为提高水质和实现水资源充分利用,提出补水减排联合控制水质达标方法,并基于农牧业需水特性配水,可避免非均衡给水情形的发生。同时,能有效降维,提升模型求解效率。以2014年为例,采用该模型优化计算,通过增加高效益的蔬菜、薯类种植面积和大牲畜的养殖数量,减少排污大的油料作物种植面积和小牲畜养殖数量,可实现考核断面水质达标,且农业配水量减少3.38%,经济效益增长11.96%,验证了该模型的有效性。再模拟分析2020年丰平枯3种典型水文年的优化配置方案,结果表明:随着可供水量的增大,农业配水、河道补水量会相应增加,大部分需水用户和子区的配水量也会随之增加。子区中的怀来县和宣化区的配水量增量较大,需水用户中谷物和水果的配水量增量较大,牲畜配水量增量小于农作物。需水用户的配水量增长率与其面积相关,子区间的配水量增长率与其区内作物类型和种植面积相关,以及水量分配是可供水量、污染排放量、经济效益综合权衡结果。该配置模型对于保障洋河流域的水质安全及区域经济可持续发展具有重大意义,并对考虑水质的水资源优化配置有一定的参考作用。     

桂林市桃花江流域生态环境需水量分析

流域生态环境需水量是生态系统的一项指标,是指在一般情况下流域生态系统本身能够通过自我调节来保证并维持生态环境的质量平衡以及其他基本功能正常的最小需水量。流域生态环境需水量按照河道的范围可以划分为两个部分,即河道内生态环境需水量和河道外生态环境需水量,因此在计算的过程中要分别确定这两个方面需水量的计算范围和计算公式。研究以桂林市桃花江流域生态环境为例,对相关的概念进行相应的介绍,并以科学的理论公式（主要是面积定额法和Tennant法）对该流域实际的生态环境需水量进行计算。通过计算分析,桃花江流域河道内、外生态环境需水量分别为0.901亿m³和0.146亿m³,分别占流域年均径流量的26.8%和4.3%。因此,应通过科学管理及提高利用效率等方式,将该流域范围内工业及生活用水总量控制在年均径流量的68%以下,以保证桃花江流域的生态环境安全。     

汤河流域水量监测及其径流量合理性分析

流域水量监测是地区水量动态控制的重要手段。通过现场监测、数据分析等方法对汤河流域水量进行实时监测,根据监测数据分析了该流域径流深和径流量的变化情况,对比分析了汤河东、西支径流深和径流量—集水面积变化曲线,通过概化方法将径流量过程线转化为三角形洪水过程线,为该流域防洪减灾等提供了数据支持和理论依据,对类似流域水量监测等具有借鉴作用。     

自然-社会水循环模型估算平原-丘陵-湿地区水稻种植潜力

自20世纪中叶以来在平原-丘陵-湿地区随着井灌水稻热的兴起,水稻种植面积急剧扩大甚至超过此类地区水稻种植潜力,引起了湿地面积萎缩、地下水水位下降和水质恶化等问题。为解决这些问题,该文构建自然-社会二元水循环模型揭示人类影响下的平原-丘陵-湿地区水循环机理,进而推算适宜的水稻种植面积。首先,利用数值法构建了基于栅格的分布式水文模型,然后在此模型中嵌入人类活动影响模型从而构建了二元水循环模型。根据水稻种植潜力阈值抽取河道水量极值、地下水最大埋深、地下水最大降深和最大地下水开采量等因素与旱田作物种类组合了18种情景模式。在满足控制阈值条件下,依据多年平均日降雨、蒸发和情景模式利用二元模型计算了各种情景的水田种植潜力,由潜力分析得:18种模式地下水最大埋深在5.17～7.49 m之间,地下水最大降深在1.67～3.73 m之间;水田处最大坡度范围0.028～0.053;河道引水量占河道水量的50%～70%;地下水开采比例在79%～112%间;水稻种植潜力为28.36万hm~2～54.12万hm~2,来自旱地面积为21.05万hm~2～40.32万hm~2,来自未利用地面积为5.68万hm~2～11.09万hm~2。以情景模式17为例在水田生育期内对河道生态需水量、地下水水位和旱地作物蒸发等进行了检验,验证得到:整个水稻生育期内分区流域地下水埋深均小于7.12m,开发水田的分区流域基流比最小值为33.45%,分区流域旱田平均蒸发与1990年土地类型情景下的分区流域旱田平均蒸发的比值大部分位于0.98～1.05,说明水稻生育期内情景17对河道水量和地下水水位的影响在控制范围内,对旱田蒸发影响比较小,因此情景模式17的水稻种植潜力是可行的。研究可为描述平原-丘陵-湿地区的水文循环过程和推求水田开发潜力提供依据。     

“绿色革命”以来大气CO2浓度升高对C3作物营养品质的影响

自20世纪60年代"绿色革命"以来,育种技术和农耕技术的发展促进了农作物产量的大幅提升,然而作物的营养品质出现下降趋势。在相似的遗传背景下,大气CO_2浓度升高会使单位体积农作物产品的营养元素含量下降,因此"绿色革命"至今,农作物产品的营养元素下降可能受大气CO_2浓度升高影响。通过植物生长箱模拟"绿色革命"初期和目前的大气CO_2浓度水平(310μmol/mol和400μmol/mol),针对主要C_3作物水稻、小麦和大豆,研究"绿色革命"以来大气CO_2浓度升高对其籽粒的C、N、Fe、Zn元素含量的影响,结果表明:CO_2浓度升高对3种作物籽粒的C元素含量几乎没有影响,变化幅度在±1.5%之间;籽粒的N、Fe、Zn元素含量普遍呈现下降趋势,但均未达到显著水平。     

Potential of wild species for genetic enhancement of some semi-arid food crops

Discovery and incorporation of genes from wild species provide means to sustain crop improvement, particularly when levels of resistance in the cultigens are low and virulent strains of pests and pathogens overcome the host plant resistance. The extent of utilization and the potential of the wild genepool for genetic enhancement were reviewed in five important food crops viz. sorghum, pearl millet, chickpea, pigeonpea and groundnut grown in the semi-arid tropics. Introgression from compatible wild germplasm in the primary gene pool resulted in transfer of new cytoplasmic male sterility systems in pearl millet and pigeonpea, development of high protein, cleistogamous flower and dwarf pigeonpea lines and foliar disease resistant groundnut cultivars. Utilization of wild species in secondary and tertiary gene pools has been generally limited due to sterility, restricted recombination or cross incompatibility. Nevertheless, these species are extremely important as they contain high levels of resistance to several important biotic and abiotic stresses. Several of them, like those belonging to the Parasorghum section and the rhizomatous Arachis species are sources of multiple resistances and hold great promise to sustain crop productivity.     

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     

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.     

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.     

Collection and preliminary evaluation of native turfgrass accessions in Italy

Despite a raising interest on turfs in Italy, all theavailable varieties of this kind in the Country are of foreign origin, and areoften poorly adapted to the prevailing climatic conditions. This prompted tobegin a collection activity of indigenous turfgrass species, with the ultimategoal of identifying promising materials for future breeding based on localgenetic resources. The collection was carried out in three areas of Italy, viz.the northern Po Plain, the coastal region of Liguria, and the island of Sardiniathat are characterised, respectively, by subcontinental, warm temperate, andtypical Mediterranean climate. Altogether, 141 sites were visited, yielding 226accessions belonging to eight species of potential interest for turfs:Poa pratensis, Poa trivialis,Festuca rubra, Festuca arundinacea,Lolium perenne, Agrostis stolonifera,Agrostis tenuis, and Cynodon dactylon,this last being a warm-season grass. Poa pratensis andCynodon dactylon were mostly collected in northern Italyand Sardinia, respectively, whereas Festuca arundinacea andLolium perenne were rather ubiquitous. The collection sitesranged from 0 to 1040 m asl, but sites over 750 m wereonly visited in the inner part of Sardinia. All the accessions, collected aswhole plants, were transplanted at Lodi, northern Italy, where they are beingevaluated. Their preliminary evaluation for traits of importance for turf use,such as sward colour and overall quality, highlighted the great variation andthe occurrence of interesting accessions in all species. Other characters wererecorded, bearing specific importance in individual species, and in all casespromising accessions were identified. The germplasm of Festucarubra, Festuca arundinacea, and Loliumperenne proved highly infected by endophytic (symbiotic) fungi of thegenus Neotyphodium.     

Enhanced establishment and growth of giant cardon cactus in an eroded field in the Sonoran Desert using native legume trees as nurse plants aided by plant growth-promoting microorganisms and compost

To evaluate the feasibility of long-term desert reforestation technology of mixed vegetation, cardon cactus (Pachycereus pringlei) seedlings from indoor and outdoor nurseries were planted in the field adjacent to one seedling of potential legume nurse trees: mesquite amargo (Prosopis articulata), yellow palo verde (Parkinsonia microphylla), and blue palo verde (Parkinsonia florida). Some of the planting holes were also supplemented with common dairy compost. Additionally, the combinations of legume tree–cactus were inoculated with either a consortium of desert arbuscular mycorrhizal (AM) fungi, plant growth promoting bacteria (PGPB; the diazotroph Azospirillum brasilense Cd, and the phosphate solubilizer Paenibacillus sp.), or a mixture of all. The field experiments were evaluated periodically during 30 months for survival and growth. Cardons reared in an outdoor screen house survived better in the field than those reared in a controlled growth chamber and hardened later outdoors. Association with any legume nurse tree increased survival and enhanced growth of untreated cardons. For cardons growing alone, application of either compost, AM fungi, and all the treatments combined increased survival. For these plants, no treatment affected plant growth during the first 3 months after transplanting. Later, all treatments, except for AM fungi, enhanced plant growth. However, only 2 years after transplanting the enhanced growth effect of AM fungi was also significant. In the presence of the legume nurse trees, transient positive effects on cardon growth were recorded. General evaluation after 30 months of cultivation showed that the treatments positively affected cardon growth when growing alone or in combination only with mesquite amargo but not with the other two legume trees. This study proposes that young legume trees have the capacity to enhance survival and growth of cardon cactus, depending on the legume cactus combination. Additional treatments such as compost or PGPB can either amplify the effect or else attenuate it.     

Karyotypic and genome size variation in Cajanus cajan (L.) Millsp. (pigeonpea) and some wild relatives

Detailed karyotypes and 4C DNA amounts have been studied in five cultivars of Cajanus cajan and 20 species belonging to Cajanus, Rhynchosia, Dunbaria, Flemingia and Paracalyx. C. cajan shows intraspecific variability and its karyotype is most similar to that of C. cajanifolius (sect. Cajanus) in the morphology and number of satellite chromosomes and the lack of any correlation between chromosome size within the complement and asymmetry. Karyotypes of C. lineatus and C. sericeus belonging to sect. Atylia are similar with respect to maximum r-index and the ratio of longest and shortest chromosomes in their respective complements. C. acutifolius (sect. Frutocosa) is distinct in having a very low ratio (1.44) between the longest and the shortest chromosomes, while in C. albicans, C. goensis, C. scarabaeoides (sect. Cantharospermum) there is no chromosome pair with r-index >2.0. C. mollis and C. volubilis (sect. Volubilis) show similarity with regard to ratio between the longest and the shortest chromosomes and a distinct chromosome pair with an arm ratio of 2.7 and C. platycarpus is distinct (sect. Rhynchosoides) in having the smallest ratio (1.36) between the longest and the shortest chromosomes. 4C DNA amounts in Cajanus and Rhynchosia vary between 3.28 pg to 11.69 pg and 4.92 pg to 11.13 pg respectively, while in Dunbaria, Flemingia and Paracalyx these vary between 4.70 and 7:06 pg. In the genus Cajanus karyotypic features and 4C DNA amounts agree with the sectional classification and bring out a close relationship between C. cajan and C. cajanifolius. This is supported by studies based on seed protein patterns, isozyme analysis, trypsin and chymotrypsin inhibitor patterns, RFLP and RAPD data and crossability relationships. A clear relation between DNA amount and abnormalities effecting the extent of pairing and recombination in interspecific hybrids shows the importance of this study in developing future breeding programme involving C. cajan and its wild relatives that are of potential value.     

Effect of some fungicide seed treatments on the survival of Bradyrhizobium japonicum and on the nodulation and yield of soybean [Glycine max. (L) Merr.]

Several commercial fungicide seed treatments were evaluated for their possible effect on the survival of Bradyrhizobium japonicum on seeds and on the nodulation and yield of soybeans in a greenhouse and a field experiment. quinolate Pro (carbendazim and oxine copper), Vitavax 200FF (carboxin and thiram), and Monceren (pencycuron) had a small effect or no effect on the survival of B. japonicum and on the nodulation and yield of soybeans. They can thus be considered compatible with soybean seed inoculation. Germipro UFB (carbendazim and iprodione), Apron 35J (metalaxyl), and Tachigaren (hymexazol) decreased B. japonicum survival and the nodulation and yield of soybeans and thus cannot be considered compatible with soybean seed inoculation.     

Leaf position and genotype differences for mineral element concentrations in sorghum grown on tropical acid soil 1

Mineral element deficiencies and toxicities are common problems associated with sorghum [Sorghum bicolor (L.) Moench] production on acid soils. To better understand some of the mineral element problems and the analysis of plant tissue of sorghum plants grown on acid soils, four sorghum genotypes were grown on an acid Oxisol at Carimagua, Colombia limed with dolomite at 2 and 6 Mg ha^‐1.

Samples for mineral element analyses were obtained from leaves at different positions on the four genotypes. Concentrations of P and Mg were highest in the flag leaf (Leaf No. 1) and decreased as the position on the plant declined from the top of the plant for plants grown at 2 Mg lime ha^‐1. Similar decreases in P, Mg, K, and Zn concentrations occurred in plants grown with 6 Mg lime ha^‐1. Concentrations of Ca, S, Si, Mn, Fe, Cu, and Al increased as leaf position declined from the flag leaf for plants grown at 2 and 6 Mg lime ha^‐1. The higher lime supply enhanced Ca and reduced Mn and Fe concentrations in leaves. Differences in mineral element concentrations for the four genotypes used were fairly extensive. The elements to show the greatest range among genotypes were Al and Si and the elements to show the least range among genotypes were P, K, and S. Care should be used in collecting leaf samples for plant analysis and genotypic differences for accumulation of mineral elements should be considered in interpretation of results.