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。     

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。     

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。     

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。     

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,     

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.     

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.