2000—2020年南昌市土地利用时空变化及其生态环境效应

[目的] 分析南昌市因土地利用变化引起的区域生态环境效应,定量研究该区域国土资源开发与生态环境的关系,为区域生态环境保护、生态文明建设和绿色发展提供科学支持。[方法] 运用土地利用转移矩阵和核密度分析模型演算土地利用变化时空变动轨迹,用生态环境质量指数和生态贡献率推理出土地利用变化对生态系统的影响。[结果] ①2000—2020年,南昌市土地利用变化主要以草地、耕地转为建设用地,林地、水域转为耕地,耕地转为水域为主; ②2000—2020年,南昌市土地利用变化空间集聚演变主要集中在西北方向,其中耕地转水域是研究区生态环境改善的主要原因,水域转耕地和耕地转建设用地是区域生态环境退化的主要原因。[结论] 南昌市2000,2010,2020年的生态环境质量指数为0.354,0.351和0.352,生态环境质量相对稳定,但区内质量指数呈现下降趋势,有必要及时严格控制城镇开发边界和落实生态红线保护政策。     

天山北坡城市群土地利用及生态服务价值时空演变

[目的] 研究天山北坡城市群土地利用及生态服务价值（ESV）的时空演变特征，为该区生态服务功能改善和生态景观建设提供理论指导。[方法] 基于2000，2010，2018年天山北坡城市群的土地利用数据，利用遥感、空间统计分析方法，分析天山北坡城市群土地利用动态变化和生态服务价值的时空演变特征，并采用景观指数模型研究了天山北坡城市群ESV的景观格局变化。[结果] ①天山北坡城市群主要用地类型为未利用地和草地，建设用地的单一动态度变化最大，动态变化幅度达2.7%；土地利用转移变化主要发生在耕地、草地、建设用地、未利用地之间，以草地向耕地和建设用地转入最为突出。②近20 a研究区ESV总量从1 410.76亿元减少到1 400.17亿元，共计损失10.59亿元，整体呈下降趋势；其中支持服务的ESV减少最多。③研究区ESV呈现出西北部和中部高，北部和东南部低的空间格局；2000-2018年研究区ESV景观格局发生显著的变化，低、中、高ESV区的景观格局表现为研究前期破碎异质化，后期集聚同质化。[结论] 针对不同等级的ESV区，天山北坡城市群的生态环境恶化，需要采取不同的措施改善其生态服务价值，降低城市群发展对生态环境造成的破坏，推动区域生态景观的建设。     

黔中城市群碳储量对土地利用/覆被变化的响应及脆弱性

[目的] 探究土地利用/覆被变化对区域生态系统碳储量及生态系统脆弱性的影响,以期为区域绿色低碳和生态系统的可持续发展提供参考依据。[方法] 以2000,2010,2020年黔中城市群核心经济区3期土地利用/覆被数据为基础,运用InVEST模型和土地利用转移矩阵定量分析生态系统碳储量及其空间分布格局,并采用潜在影响指数(PI)对区域生态系统服务脆弱性进行评估。[结果] ①2000-2020年,黔中城市群核心经济区土地利用/覆被变化总体表现为耕地和林地持续下降,建设用地持续上升。研究区土地利用/覆被转移主要表现为耕地、林地、草地向其他地类的转移,其中,2000-2010,2010-2020年分别有3 339.35,3 669.15 km²土地发生了转移,前者林地转为草地是主要转移类型,后者耕地转为建设用地为主要转移类型。②2000-2020年区域的碳储量表现为减少趋势,由4.42×10⁷ t减小到4.33×10⁷ t,累计减小9.40×10⁵ t,林地转为草地是引起碳储量减少的主要原因。各年度碳储量密度均呈现西部、东部高,中部低的分布态势;20 a间,高密度区未发生明显变化,低密度区表现为由中心区域向外围扩散。③2000-2020年黔中城市群核心经济区主要扮演碳源的角色,土地利用程度指数增加了2.83,PI指数分别为-0.04,-0.31,均表现为负面潜在影响,且脆弱性不断增强。[结论] 增加林地、控制林地转为其他用地及建设用地扩张是促进区域绿色低碳和生态系统的稳定可持续发展的重要手段。     

基于GlobeLand 30数据和CA_Markov模型的郑州市2000-2020年地表覆盖变化特征及预测分析

[目的]针对不同分类算法对地物识别结果的差异性导致地表覆盖变化分析难以为城市变化提供参考信息和决策依据问题.[方法]研究以GlobeLand 30标准产品为数据源,结合CA_Markov模型,对郑州地区2000 2020年土地利用变化速度、幅度、程度,以及熵值演变方向等时空变化特征进行分析与模拟预测.[结果] (1) 2000-2010年,郑州地区人造地表显著增加,湿地、耕地、草地有一定程度的减少,其中人造地表和湿地的变化速度相对较快;(2) 2000-2010年,郑州地区土地利用程度变化量为8.04,土地利用信息熵和均衡度都有所提升,优势度相应降低;(3)预测2020年郑州地区地表覆盖状态同2010年相比,人造地表和草地分别增加68.88％和49.99％,水体、湿地增加幅度均在30％以上,耕地、林地有一定程度的减少.[结论] 2000-2020年,郑州地区土地利用总体分布格局具有显著性差异,土地利用的复杂性增加,环境问题日益凸显.     

引黄济青工程沿线生态因子1990-2020年时空变化特征

[目的]以引黄济青工程为研究对象,探究其通水1990-2020年间沿线生态因子的时空变化规律,为该区生态环境的保护和治理提供依据.[方法]采用遥感技术对土地利用/覆盖、植被指数及覆盖度、地表温度、土壤干湿度等因子1990-2020年的时空演变特征展开研究,深入探究工程运行后沿岸生态环境的变化.[结果]区域内水域、绿地、...     

成都平原农地利用方式转变对不同母质土壤剖面磁化率的影响

[目的]分析区域土壤磁化率变化特征有助于掌握土壤环境变化规律和土壤演化特点,为区域土壤资源管理提供依据.[方法]本研究基于174个土壤剖面的675个采样数据,分析成都平原不同农地利用方式和母质条件下土壤剖面磁化率的差异,采用时空替代法探究农地利用方式转变对农田土壤剖面磁化率的影响.[结果]结果表明,研究区土壤磁化率随土...     

苏州市土地利用变化的生态环境效应研究

以苏州市为例,利用1980年、1995年、2000年三期TM遥感影像解译图获取土地利用变化数据.首先,对苏州市1980-1995年和1995-2005年两个时段的土地利用变化特征进行分析.然后,通过定义不间土地利用类型的相对生态服务价值,分别运用区域牛态环境质量指数和区域土地利用变化类型生态贡献率,对研究时段内苏州市土地利用变化的生态环境效应以及导致苏州市生态环境质量变化的主导土地利用变化类型进行分析与评价.结果表明,1980-2005年苏州市的生态环境质量不断下降.苏州市的生态环境质量指数从0.460 9下降No.443 1,且下降速度越来越快.其中,导致苏州市牛态环境质量恶化的主要土地利用变化类型是耕地向城乡建设用地的转变,促进苏州市生态环境质量改善的主要土地利用变化类型足耕地向水域用地的转变.     

凉山地区生态环境脆弱性的时空动态变化

[目的]了解凉山地区2000 2010年生态环境脆弱性动态变化状况,为地区生态环境治理与保护提供参考依据.[方法]将RS与GIS技术相结合,以生态敏感性—生态恢复力—生态压力度(SRP)为模型选取16个评价指标,利用空间主成分综合与动态变化分析模型从时间与空间相结合角度,对凉山地区2000 2010年生态环境脆弱性动态变化进行定量分析.[结果]凉山地区生态环境脆弱性整体呈现南高北低的分布规律,就单一动态度而言潜在脆弱最大中度脆弱最小,就综合动态度分析该地区整体变化速度接近中度水平,而生态脆弱性综合指数则反映出该地区整体生态环境脆弱性有缓慢恶化趋势.[结论]凉山地区生态环境脆弱性空间分布规律明显,生态环境治理力度仍需加大.     

基于ArcGIS的淮河流域大别山区土地利用变化与土壤侵蚀特征研究

土地利用变化改变了原有地表植被类型、覆盖度和微地形,从而使区域土壤侵蚀特征发生变化.因而土地利用类型是土壤侵蚀强度划分的重要参考指标.选取2000年土地利用类型图与1995-2000年的土壤侵蚀图,借助ArcGIS软件技术分析了大别山区1995-2000年的不同土地利用类型的土壤侵蚀变化特征,揭示了区域土地利用/土地覆被变化的基本规律及其土壤侵蚀变化的基本过程,为区域水土流失治理的工程与技术措施提供依据.     

1990-2014年甘肃省白龙江流域土地利用变化对人类活动响应

[目的]综合分析1990-2014年甘肃省白龙江流域土地利用变化及其对人类活动的响应,以期为该区未来的土地利用优化提供参考.[方法]基于1990年,2002年,2014年3期遥感影像解译获取的土地利用数据,计算土地利用变化速度、土地利用转移矩阵和土地利用程度.[结果] 1990-2014年流域的综合土地利用动态度从10.24％增长到17.59％;1990-2014年流域的土地利用类型变化以草地、耕地和林地的转换为主;1990-2002年流域内各县(区)的土地利用程度综合变化指数介于1.38～6.65,而2002-2014年流域内各县(区)的土地利用程度综合变化指数介于一15.43～0.17.[结论]1990-2014年流域人类活动对土地的利用由简单索取开发型转变为保护与生态建设型,从破坏性、粗放式和低利用效率向保护性、集约式和高利用效率发展.     

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.