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1.
安塞县土地利用变化与经济发展的关系 总被引：9，自引：1，他引：8
通过对陕西省安塞县近年来土地利用变化及与当地经济发展的关系分析,可以看出,随着当地石油资源的开采,县域经济的发展、市场结构的变化,土地利用方式和类型也发生了相应的改变.耕地面积,特别是坡耕地面积减少,以果园、蔬菜大棚为代表的高技术、高产值的农产品增加、以林地为代表具有良好生态效益的土地利用面积扩大.进而促进了第三产业的发展、社会消费品零售总额增加、城镇化水平提高,当地农民个人纯收入由1989年的200多元提高到2004年2000多元. 相似文献
2.
土地利用格局优化有利于实现土地资源高效利用,以砒砂岩区西黑岱流域为研究对象, 以侵蚀防控为目标,基于不同时期的土地利用现状图和地形图等数据, 采用线性规划法和元胞自动机（CA）模型,在GIS技术的支持下,对西黑岱流域的土地利用格局变化与优化进行了研究,结果表明:研究期内耕地、林地在不断地增加,其中林地面积的增加最大,草地面积的减少幅度很大,水域面积有所减少,建设用地略有所增加。优化后耕地总面积增加了20.67 hm2,林地面积明显增加至1 501.89 hm2,所占比重超过了草地;而草地面积减少了157.68 hm2,此次优化使得西黑岱流域土地利用结构发生明显的变化,其中林地面积在大幅度的提高,耕地、草地向高质量方向发展,通过土地优化将减少土壤侵蚀,保护当地脆弱的生态环境,提高综合生产力,同时为砒砂岩区进行土地利用格局优化调控提供依据。 相似文献
3.
鹞落坪自然保护区土地利用动态格局研究 总被引：1，自引：1，他引：0
[目的]分析1994—2017年鹞落坪自然保护区土地利用格局变化特征,揭示退耕还林、生态旅游等对保护区土地格局变化的影响,为保护区林地保护与利用提供依据。[方法]以1994,2002,2012和2017年4期LandsatTM/ETM~+/OLI遥感影像为数据源,采用监督分类提取研究区土地利用信息,并建立转移矩阵,分析保护区20 a间土地利用格局动态变化及其转移特点。[结果] 1994—2017年保护区内土地利用结构发生了较为明显的变化,林地、居民地和园地面积都有不同程度的增加,而耕地显著减少。土地利用类型主要转移方向为耕地转化为园地、林地和居民地,小部分林地转化为居民地。1994—2002年区内林地面积大幅度增加,耕地面积大量减少;2002—2012年居民地呈现出扩张的趋势,园地面积大幅度增加,耕地面积则有所减少;2012—2017年区内土地利用转化量相对较小,居民地、林地以及园地面积小幅度增加,耕地面积相对减少。[结论]保护区土地利用格局变化是退耕还林、茶业发展和旅游开发共同作用的结果。退耕还林导致耕地面积减少,林地和园地面积增加;旅游开发导致居民用地面积增加。 相似文献
4.
《水土保持应用技术》2015,(3)
利用延吉市1997和2007年TM遥感数据,在RS和GIS技术的支持下,运用灰色预测模型预测了延吉市未来10 a研究区土地的变化情况。结果表明,1997—2006年研究区域内的不同利用类型的土地面积发生了很大变化,主要以农业耕地和城镇、工矿用地以及居民用地面积的大幅度增加为主,其次,其他利用类型的土地面积变化将逐渐趋于一个较为平稳发展的状态。为了实现合理利用土地资源,保护生态环境,促进社会的可持续发展的目标,应该采取相应的对策。 相似文献
5.
青岛市1990-2011年土地利用/覆被变化研究 总被引：3，自引：1，他引：2
基于青岛市1990,2000,2006年LandsatTM影像和2011年‘HJ-1’卫星影像,采用土地利用动态变化模型,分析了青岛市1990-2011年土地利用/覆被变化(LUCC)情况.结果表明,21 a间青岛市土地利用状况变化显著.(1)耕地、草地面积减少,城乡、工矿、居民用地增加,林地面积先减少后增加,水域和未利用土地则呈现先增加后减少的态势;(2)青岛市土地利用程度逐年提高,说明青岛市正处于土地利用发展时期,土地利用集约度将进一步提高;(3)空间上,中部和东部地区变化显著,北部和西南部变化相对较小.土地利用变化类型转换关系复杂,主要向城乡、工矿、居民用地转化. 相似文献
6.
1990-2018年东江流域土地利用变化及其驱动力 总被引：2，自引：2，他引：0
[目的] 分析东江流域1990-2018年土地利用时空变化特征及驱动机制,为该流域土地利用优化提供科学参考。[方法] 利用流域土地利用数据及统计年鉴数据,结合土地利用评价指标、主成分分析法及灰色关联分析法分析流域土地利用变化特征及其驱动机制。[结果] ①东江流域1990-2018年土地利用以耕地和林地为主,流域建设用地面积持续增加,其余地类面积均呈减少趋势,耕地和林地是建设用地面积的主要来源;②流域土地利用综合指数逐年增加,变化率为0.038,土地利用处于上升发展阶段;③流域土地利用变化驱动力主要为经济增长、人口增长、社会富裕程度和农业发展;各类驱动因子对各土地利用类型的驱动作用不同。[结论] 1990-2018年,东江流域土地利用结构不断优化,土地利用集聚程度增加,随着粤港澳大湾区的建设开发,未来流域内土地开发利用活动将更加频繁。 相似文献
7.
为探究延河流域土地利用演变规律及未来空间格局分布,基于延河流域1986年、2000年和2010年3期土地利用数据,利用土地利用空间转移动态图及土地利用转移面积矩阵等方法,分析了延河流域1986—2010年土地利用/覆被变化的时空规律; 运用Logistic-CA-Markov模型和MCE-CA-Markov模型分别预测了2030年延河流域土地利用空间格局,并对模拟结果进行了对比分析。结果表明:延河流域1986—2010年耕地降幅最为明显,减少了557.10 km2,主要转为草地、林地和建设用地; 林地和草地面积持续增加,建设用地扩张迅速,分别增加了378.34,136.97,48.17 km2,水域及未利用地面积总体变化不大,生态恢复政策是影响延河流域土地利用变化的主要因子。Logistic-CA-Markov预测得到的2030年延河流域耕地和草地减少明显,建设用地和林地则增幅较大,流域经济发展需求较高,这种情况下应准确把握地区经济发展与资源利用的关系,根据区域特点因地制宜制定适合当地发展的政策。而MCE-CA-Markov预测得到的2030年延河流域耕地、林地、水域及建设用地均有增加,且耕地增幅最明显,这种利用结构表明流域经济发展相对较缓,实现了对流域环境的保护,但应积极探索土地利用新结构,最大限度发挥资源优势,从而实现流域经济与环境的可持续性发展。 相似文献
8.
针对三江平原农业用水、用地结构不合理,难以发挥系统最大效能问题,以农垦建三江分局2011年数据为基础,运用复杂适应系统的思想,构建了三江平原农业水土资源复杂适应性配置模型,并对不同地下水开采方案下的农业水土资源优化配置进行了演化分析。结果表明:随着地下水开采量的增加,农业产值和粮食产量都有所增加,生态面积在一定范围内有所减少。随着地下水开采量的减少,其高效利用的土地面积会随之减少,造成大量的土地不能有效得到利用,严重阻碍了区域水资源与土地资源的耦合与当地经济的发展,上述非线性关系以及各子系统对水量变化敏感程度的不同正是其适应性的表现。研究成果对于指导三江平原科学合理的开发利用农业水土资源,提高农业水土资源的利用效率具有重要的理论和实践意义。 相似文献
9.
以陕西省长武县为研究区域,根据大规模采样数据,结合1983年和2008年土地利用空间数据,运用定位对比监测方法,分析了25年来不同土地利用变化的幅度、空间分布特征和方向,并对这种变化影响下的土壤有机质含量演化特征进行了研究。结果表明:该区土地利用方式在这一时期变化显著,旱地、草地、非农用地面积大幅减少,林地、果园面积大幅增加。土地利用方式的转变已经成为土壤有机质含量变化的驱动因素,其中,旱地转变为林地和果园,土壤有机质含量变化明显,分别增加了6.6 g/kg和5.11 g/kg,而林地转变为旱地和草地则无明显增量。土壤有机质含量的变化不仅改变了土壤结构,有效地控制了水土流失的发生,而且为该区域的土地利用方式朝着健康的方向发展,提供了参考价值。 相似文献
10.
基于CA-Markov模型的黄土丘陵区土地利用变化 总被引：9，自引：4，他引：9
为探讨黄土丘陵区的土地利用变化规律以及驱动机制,以罗玉沟流域作为典型流域,基于1986、2001年的TM影像为数据源,对土地利用格局分布进行分析,并运用CA-Markov模型,以2001年的土地利用格局为基础,预测了2016年流域的土地利用的空间格局分布。结果表明,罗玉沟流域土地利用格局在1986年以前,以坡耕地为主,面积占59.67%,其次为梯田、草地和林地。从1986年到2001年林地和梯田的面积均有显著增加,坡耕地面积则显著减少,其余土地利用类型面积变化不大。从单一土地利用类型动态度来看,面积增加大 相似文献
11.
【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。 相似文献
12.
Kyle Devey Michael Mucalo Gordon Rajendram Joseph Lane 《Communications in Soil Science and Plant Analysis》2015,46(4):72-80
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. 相似文献
13.
《中国生态农业学报》2014,(8)
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, 相似文献
14.
M.A. Callaham Jr. J.M. BlairT.C. Todd D.J. KitchenM.R. Whiles 《Soil biology & biochemistry》2003,35(8):1079-1093
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. 相似文献
15.
Grete Skrede Berit Karoline Martinsen Anne-Berit Wold Stein-Erik Birkeland Kjersti Aaby 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(3):193-208
Abstract A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species. 相似文献
16.
《Communications in Soil Science and Plant Analysis》2012,43(7):865-877
Potassium (K) fixation and release in soil are important factors in the long-term sustainability of a cropping system. Changes in K concentration and characteristics of K fixation and release in rhizosphere and nonrhizosphere soils in the rapeseed (Brassica napus L.)–rice (Oryza sativa L.) rotation were investigated using a rhizobox system. The concentrations of different forms of K in both rhizosphere and nonrhizosphere soils decreased with plants compared to without plants, regardless of K fertilizer application. Potassium uptake by crops mainly came from the rhizosphere soil. In the treatment without K fertilizer (–K), the main form of K supplied by the soil to the crops was 1.0 mol L?1 nitric acid (HNO3) nonextractable K, followed by nonexchangeable K, and then exchangeable K. In the treatment with K fertilizer (+K), the main K forms supplied by the soil to the crops were exchangeable K and nonexchangeable K. The amount and rate of K fixation after one cycle of the rapeseed–rice rotation was greater in rhizosphere soil than in nonrhizosphere soil. The amount and rate of K fixation of soil in the +K treatment were significantly less than in the –K treatment. The cumulative amounts of K released with 1.0 mol L?1 ammonium acetate (NH4OAc) and 1.0 mol L?1 HNO3 extraction increased with the increasing numbers of extractions, but the K-releasing power of soil by successive extraction decreased gradually and finally became almost constant. The release of K was less in rhizosphere soil than in nonrhizosphere soil. The release of K in the +K treatment was similar to that in the –K treatment in rhizosphere soil, but the K release in nonrhizosphere soil was greater with the +K than the –K treatment. Overall, the information obtained in this study will be helpful in formulating more precise K fertilizer recommendations for certain soils. 相似文献
17.
Electron donor and pH relationships for biologically enhanced dissolution of chlorinated solvent DNAPL in groundwater 总被引：3，自引：0，他引：3
Biologically enhanced dissolution offers a method to speed removal of chlorinated solvent dense non-aqueous-phase liquid (DNAPL) sources such as tetrachloroethene (PCE) and trichoroethene (TCE) from aquifers. Bioremediation is accomplished by adding an electron donor to the source zone where fermentation to intermediates leading to acetic acid and hydrogen results. The hydrogen and possibly acetic acid are used by dehalogenating bacteria to convert PCE and TCE to ethene and hydrochloric acid. Reductive dehalogenation is thus an acid forming process, and sufficient alkalinity must be present to maintain a near neutral pH. The bicarbonate alkalinity required to maintain pH above 6.5 is a function of the electron donor: 800 mg/L of bicarbonate alkalinity is sufficient to achieve about 1.2 mM TCE dechlorination with glucose, 1.7 mM with lactate, and a much higher 3.3 mM with formate. Laboratory studies indicate that in mixed culture, formate can be used as an electron donor for complete conversion to ethene, contrary to pure cultures studies indicating it cannot. Various strategies can be used to add electron donor to an aquifer for DNAPL dehalogenation while minimizing pH problems and excessive electron donor usage, including use of injection-extraction wells, dual recirculation wells, and nested injection-extraction wells. 相似文献
18.
Aleš Lebeda Ivana Doležalová Eva Křístková Barbora Mieslerová 《Genetic Resources and Crop Evolution》2001,48(2):153-164
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. 相似文献
19.
Three slow-growing legume trees used for desert reforestation and urban gardening in the Sonoran Desert of Northwestern Mexico
and the Southwestern USA were evaluated whether their growth can be promoted by inoculation with plant growth-promoting bacteria
(Azospirillum brasilense and Bacillus pumilus), unidentified arbuscular mycorrhizal (AM) fungi (mainly Glomus sp.), and supplementation with common compost under regular screenhouse cultivation common to these trees in nurseries. Mesquite
amargo (Prosopis articulata) and yellow palo verde (Parkinsonia microphylla) had different positive responses to several of the parameters tested while blue palo verde (Parkinsonia florida) did not respond. Survival of all tree species was over 80% and survival of mesquite was almost 100% after 10 months of cultivation.
Inoculation with growth-promoting microorganisms induced significant effects on the leaf gas exchange of these trees, measured
as transpiration and diffusive resistance, when these trees were cultivated without water restrictions. 相似文献
20.
Y. Bashan J. J. Bustillos L. A. Leyva J.-P. Hernandez M. Bacilio 《Biology and Fertility of Soils》2006,42(4):279-285
Inoculation of wheat seedlings with the plant growth-promoting bacterium Azospirillum brasilense Cd was immobilized in alginate microbeads and, without applying any stress, significantly increased the quantity of several
photosynthetic pigments, such as chlorophyll a, chlorophyll b, and the auxiliary photoprotective pigments violaxanthin, zeaxanthin, antheroxanthin, lutein, neoxanthin, and β-carotene.
This resulted in greener plants with no apparent visible stress. After monitoring the quantity of photosynthetic pigments
for 4 weeks, we observed that inoculated plants had higher quantities of pigments in shoot and stem. The greatest difference
in the quantity of all pigments between inoculated and noninoculated plants occurred in the first week of growth. Regardless
of treatment, the quantity of pigments in stems was three to four times less than the quantity of these pigments in shoots.
Application of Azospirillum, either as liquid inoculant or as alginate microbeads, did not alter the positive effect of the bacteria on pigment production
or the positive response of the plants towards A. brasilense Cd inoculation. 相似文献