长江上游生态脆弱区土地利用结构及生态服务价值变化响应——以甘肃省陇南市为例

利用陇南市2003—2008年土地利用变更调查数据和相关统计资料,运用景观生态学中的结构定量方法分析,计算出土地利用结构指数和生态服务价值,分析土地利用结构与生态服务价值的变化及其相互关系。结果表明:2003—2008年陇南市土地利用结构多样性指数和均匀度增加而优势度降低。林地提供的生态服务价值最大,土地利用生态服务价值总体呈增加趋势,土地利用生态服务价值与土地利用结构线性相关。     

重要水源地东圳水库水质变化及其影响因素研究

以地处喀斯特石山区的广西省河池市为例,以研究区单位面积农田生态系统在1988,1998和2003年提供的食物生产服务经济价值为基础,对研究区生态服务功能价值进行估算,并对照3个年份土地利用变化与生态服务功能价值的变化,找出了不同时段土地利用结构变化所引起的生态服务功能价值响应与变化特征.研究结果表明,1988-2003年河池市土地利用变化产生了较大的生态响应,生态服务功能价值总体上呈增长趋势;1988-1998年除了农田生态系统服务功能价值增长仅14.6%外,其它各类生态系统增幅都在25.9%以上;1998-2003年增幅明显减趋缓,草地生态服务功能价值则呈现急剧下滑状态,变化特征基本上与土地利用变化一致.河池市土地利用方式还需要进一步改善,尤其对面积广大的未利用地的生态改造和石漠化地区的生态恢复将会带来更大的生态效益.     

汉中市土地利用时空变化及其对生态系统服务价值的影响

汉中市地处气候南北分界线的秦岭—巴山两大山系之间,是国家级重点生态功能区,同时也是"南水北调"中线引水工程的主要水源保护地。对汉中市土地利用变化及其生态服务功能价值影响的研究可为水源保护以及环境质量的改善提供重要理论依据和决策支持。利用遥感和GIS技术分析了汉中市1990—2015年的土地利用变化特征及其对区域生态服务价值的影响。结果表明:1990—2015年汉中市林地和建设用地面积呈增加,而草地、耕地、水域和未利用地则呈减少的趋势。2010年以来土地利用变化速率明显加快,地类之间的转化更为频繁,人类活动对土地利用的影响明显加强。土地转移主要发生在略阳县、勉县、宁强县、西乡县和镇巴县。1990—2015年汉中市土地利用的年总生态服务价值持续增加,特别是林地的生态服务价值增加幅度较大。林地面积增加使得1990—2015年汉中市的原材料生产、气候调节、气体调节、生物多样性保护土壤形成与保护和提供娱乐文化生态功能占年总价值的比值增加。林地、耕地和水域是汉中市生态服务的主要贡献者,也是生态服务价值变化的敏感因子。     

长武县土地利用/覆被演变规律及其影响下生态服务价值变化研究

研究长武县近30年来的土地利用/覆被变化及其生态服务价值响应,明确人类活动对该区域环境的影响,有利于辅助政府制定合理土地利用政策,改善生态环境。在1990—2015年时段内,选择五个时间节点,从土地类型变化趋势、变化速率、转换关系及综合利用度等方面研究长武县土地利用/覆被演变规律,并在此基础上,结合长武县实际情况分析其生态服务价值的变化。结果表明:研究时段内耕地、草地等面积呈减少趋势,林地、园地、工矿用地、居民地等面积呈增加趋势;土地综合利用程度略有下降,土地利用处于调整时期;土地利用/覆被变化使长武县生态服务价值发生变化,其中林地生态服务价值增加62.33%,园地生态服务价值增加近8.5倍,耕地生态服务价值减少53.67%;长武县生态系统的气体调节、水源涵养、生物多样性保护指标等服务价值呈增加趋势,生态环境明显改善。     

海伦市资源演化格局与土地利用变化及其生态效应分析

以黑龙江省海伦市为例, 运用1980 年、1995 年和2000 年的土地利用数据与实地调查相结合, 对20年间海伦市土地利用演化过程进行了分析; 利用生态服务价值理论与方法, 分析了海伦市土地利用变化对生态服务价值的影响程度。结果表明: 1980~2000 年间, 海伦市的耕地、城镇用地、交通用地呈增加趋势, 而林地、草地及湿地则呈减少趋势。区域生态效应(生态服务价值)随土地利用类型的变化而变化, 耕地对生态效应的贡献率最高, 为43.67%(2000 年); 其次是湿地和林地, 分别为26.32%和14.96%(2000 年); 居民点及工矿用地对生态效应的贡献率为负值。1980~2000 年间海伦市土地利用的生态服务功能在食物生产功能方面明显增强, 而在气体调节、气候调节、废物处理、土壤形成、侵蚀控制、原材料利用和娱乐文化等方面有所下降, 说明城市的快速发展和粮食生产能力的提高, 在一定程度上导致了区域整体生态效应的下降。     

内蒙古1990-2018年土地利用变化及生态系统服务价值

利用内蒙古自治区1990年、1995年、2000年、2005年、2010年、2015年、2018年7期TM/ETM影像作为数据源，基于GIS方法提取内蒙古自治区各年的土地利用数据。采用中国陆地生态服务价值表的计算方法对内蒙古自治区的土地利用数据进行分析，计算内蒙古自治区的生态服务价值。结果表明：1990-2018年内蒙古自治区土地利用各地类整体在时空上呈变化趋势，具体变化为耕地、林地和未利用土地呈下降趋势，草地和城镇建设用地呈增长趋势，其中未利用土地减少面积最多，草地增幅最大；结合土地利用转移矩阵可知，减少的未利用土地、林地和耕地主要都转化为草地；近30年内蒙古的生态服务价值总体呈现增长趋势，其中草地生态服务价值最高，未利用土地的生态服务价值最低，与土地利用变化情况相同；生态服务价值的敏感性指数均<1，这说明近30年内蒙古地区的生态服务价值相对较稳定，结果可信。     

石家庄市土地利用变化及其生态服务功能响应

[目的]探究土地利用变化对生态服务功能的影响,为今后研究区实现社会经济发展与生态环境稳定、土地可持续利用与发展提供理论依据和决策方法。[方法]利用河北省石家庄市2000年和2010年的遥感影像数据,解译该2期土地利用类型图。并对2期土地利用图进行变化速度、内部转移矩阵、空间叠加分析,了解近10a来研究区的土地利用特征。应用谢高地和Costanza的研究经验,结合研究区实际,对生态服务功能价值进行计算,并作敏感性分析。并从单项生态服务功能价值、各土地利用类型生态服务价值对生态服务功能价值影响、生态服务价值流向等方面对土地利用变化的生态服务功能响应进行研究。[结果]土地利用变化是引起生态系统服务价值变化的主要原因,其中林地和低矮灌木及草地生态系统对生态系统服务价值的提高有显著影响。[结论]研究区10a间土地利用变化十分明显,土地利用整体趋势呈平衡状态,土地利用方向基本合理;保护区土地利用变化对生态服务功能影响显著,林地为主要土地利用类型,对生态服务功能影响最为显著。     

开封市土地利用时空变化的生态系统服务价值评估

选取开封市1990-2010年四期土地利用的动态数据,采用Costanza、谢高地等提出的生态系统服务价值公式和系数,对开封市生态系统服务价值进行定量分析。结果表明:1990-2010年间生态系统服务价值从51.714 86亿元减至50.294 62亿元,生态系统服务价值年均变化率为0.137%,土地利用变化引起生态服务价值呈下降趋势,年均减少7.101 2万元。表明该市土地利用规划在取得经济效益的同时,却导致了土地生态效益的降低。因此,制定合理的土地利用规划,采取合理的土地利用方式,建立可持续的土地利用模式,从而在社会经济发展的同时提高土地利用的生态效益。     

干旱区绿洲土地利用变化的生态系统服务价值响应——以甘肃省金塔县为例

通过运用土地利用类型动态度、土地利用程度模型、生态系统服务价值估算模型和土地利用调查和变更数据等,分析1990年、2000年和2008年金塔县土地利用变化及其生态系统服务价值变化特征。结果表明:(1)1990—2008年间,耕地、园地、林地、建设用地和水域呈现增加趋势,牧草地和未利用地面积表现为减少趋势,总体土地利用程度为中下水平,处于发展阶段。(2)研究期间生态系统服务总价值呈现上升趋势,从1990年的47.238亿元增加到2008年的48.228亿元(+0.989 9亿元)。水域在研究区生态系统服务总价值中所占份额最大,草地生态服务功能的下降对生态系统服务总价值有明显的负贡献。(3)研究区各类生态系统的生物多样性保护、水源涵养和废物处理等服务性功能价值远大于其粮食生产和原材料等生产性功能价值。因此,该区域水土资源的合理利用与有效管理是实现生态系统服务功能维持和可持续发展的根本。     

西部绿洲城市土地利用转型的生态环境效应——以乌鲁木齐市为例

为探讨土地利用转型对生态环境变化的影响,基于乌鲁木齐市2005年和2012年TM影像数据、土地利用现状矢量数据、中国高空间分辨率网格数据(CHRED),运用土地利用转型、生态系统单位面积生态服务价值评估和碳排放核算等方法,分析城市化过程中乌鲁木齐市土地利用转型前后生态环境变化效应。结果表明,研究区土地利用转型幅度较大,其中园林地、草地、城镇村及工矿用地和未利用地之间的转换较明显,未利用地转出面积最大(10.33万hm-~2),说明研究区土地开发程度较高。研究区生态服务价值均呈增加趋势,研究期间生态服务价值增加了89 227.32万元,其中,园林地、草地和水域土地利用转型对生态系统服务价值增加的贡献高。研究区土地利用碳排放量呈上升趋势,碳排放量较高的是城镇村及工矿用地。研究区内土地利用转型后净生态系统服务价值呈现增加趋势,但土地碳排放量变化速度远超生态系统服务价值增加速度,因此在乌鲁木齐市低碳城市建设中,要充分考虑土地利用结构调整与生态环境保护的平衡关系。     

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.     

“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.     

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.     

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     

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.     

Einfluss der düngungsmethoden auf die entwicklung von zuckerrübenkrankheiten

Während neunjähriger (1994-2002) Untersuchungen in der Versuchsanstalt Ba?cyny (Fahlerde, Fall-Gleyboden, ausgebildet aus leichtem Lehmboden) wurde der Befall mit Krankheiten an der Zuckerrübe in Abhängigkeit von der Düngungsmethode bewertet. Folgende Methoden wurden angewendet: A - Mineraldünger, B - Stalldung und Mineraldünger, C - Stroh-, Gründung und Mineraldünger, D - Kompostdünger und Biopräparate (ökologische Düngung). Auf den Objekten A, B, C wurden bei konstanter Phosphor-Kalium-Düngung die Stickstoffgaben von 0 bis 180 kg.ha^?1 differenziert. Auf dem ökologischen Objekt D ohne Mineraldünger wurden statt Stickstoff die Biopräparate P₅₀₀ und P₅₀₁ verabreicht. Der geringste Befall von Krankheiten wurde an der Zuckerrübe auf jenem Objekt festgestellt, das mit Kompost und den Biopräparaten gedüngt worden war. Im Rahmen der konventionellen Düngungsmethoden wurde allgemein die höchste Intensität der Krankheiten an der mit Stroh, Gründung und Mineraldünger gedüngten Zuckerrübe beobachtet. Ausnahmen von dieser Regel bildete das Vorkommen von echtem Mehltau und Keimlingsfäule. Auf den Objekten A, B, C nahm die Intensität der Krankheiten mit der Steigerung der Stickstoffgabe zu. Auch die auf Objekt D verabreichten Biopräparate stimulierten die Entwicklung der Krankheiten. The effect of various fertilization methods on the diseases of sugar beet was estimated on the basis of nine-year studies (1994-2002) conducted in the Experimental Production Farm in Ba?cyny on loess-based, sedimentary-gley, light-clay soil. The following fertilization methods were applied: A - mineral fertilization, B - mineral and manure fertilization, C - straw, green manure and mineral fertilization, D - ecological compost and biodynamic preparations fertilization. In the objects A, B and C fertilized with phosphorus and potassium, various doses of nitrogen ranging from 0 to 180 kg/ha^?1 were used. In the ecological object D, where mineral fertilization was not used, biodynamic preparations P₅₀₀ and P₅₀₁ were applied instead of nitrogen. The lowest ratio of the diseases of sugar beet was observed in the object fertilized with the compost and biodynamic preparations. In view of the conventional fertilization methods, generally the highest incidence of diseases was noted in the sugar beet fertilized with straw, green manure and mineral fertilizers. The exception was the occurrence of powdery mildew and the black leg. In objects A, B and C the incidence of the diseases increased with the increase in nitrogen doses. The applied biodynamical preparations in the object D stimulated the development of diseases too.     

Prospects for control of Pythium damping-off of lettuce with Trichoderma,Gliocladium and Enterobacter spp.

Summary Damping-off of lettuce (Lactuca sativa) caused by Pythium ultimum was studied in pots containing a non-sterile potting mix in the glasshouse. Fifty P. ultimum sporangia g^-1 compost reduced the plant stand to 15% and shoot dry weight to 18%, but this reduction was totally prevented by applying Trichoderma harzianum at 2×10⁵ viable propagules g^-1 potting mix. Gliocladium virens and Enterobacter cloacae also alleviated the damping-off. E. cloacae did not adversely affect the action of the fungal antagonists. The co-existence of the bacterial and fungal antagonists was revealed on the root surface and inner surface of the testa by scanning electron microscopy, indicating the compatibility of the biocontrol agents.