近20年渭干河流域土地利用与生态系统服务价值时空变化

基于遥感与GIS技术,选择地处天山山脉中段南麓塔里木盆地北部的渭干河流域为研究区,以新疆1990、2000、2008年遥感影像和地面实测数据为主要数据源,利用GIS空间分析、数学统计分析方法提取渭干河流域近20年各种土地利用类型的面积变化、净变化速度等动态变化信息;在总结生态系统服务价值国内外研究进展的基础上,参照谢高地等人的中国陆地生态系统单位面积服务价值系数和Costanza等的生态系统服务价值计算公式,结合当地粮食产量和粮食平均收购价格,分析渭干河流域生态服务价值的时空变化特征,揭示渭干河流域生态系统服务价值和时空分布的不平衡状态.结果如下:(1)草地和未利用地所占比重超过70％,其他土地利用类型所占比重不到20％,各种土地利用类型分布和面积变化存在时空差异.(2) 1990-2008年研究区的生态系统服务价值总量减少了59 633万元,其主要原因是草地、林地和沼泽面积的减少.流域生态系统服务价值结构变化较大,其提供的支持服务功能最强,供给服务功能相对较弱.(3)下游的单位面积生态系统服务价值大于中上游地区,研究期内流域中、下游生态系统服务价值减少较大,上游地区的生态系统服务价值略有增加.     

石羊河流域上游生态系统服务价值的变化研究

研究土地利用变化对区域生态系统服务价值的影响具有重要意义。以石羊河流域上游2000年和2006年30×30m分辨率的Landsat TM图像解译数据为基础,采用谢高地等人制定的中国陆地生态系统单位面积服务价值表,估算了石羊河流域上游土地利用变化引起的生态系统服务价值变化。研究结果表明:2000～2006的6年间,土地利用变化损害了该区域生态系统的服务功能,使生态系统服务价值从2000年的100亿元降低到2006年的97.18亿元,损失了28.82亿元,减幅达2.82%。应加强祁连山水源涵养林区、天然草场的保护和建设,加强耕地和湿地的封育保护,合理控制城镇建设用地的扩展,尽可能恢复和提高石羊河流域上游生态系统服务功能。     

黑河流域水化学空间分异特征分析

选取我国西北干旱区第 2大内陆河———黑河流域 ,对全流域地表水和地下水的水化学类型和水化学特征进行了系统分析。结果表明 ,黑河流域地表水中TDS (阴离子总量 )和主要离子含量沿流程均有不同程度的增加 ,但增幅不大。而地下水TDS从莺落峡出山后呈直线上升 ,下游TDS均大于 10 0 0mg/L ,主要离子含量增加明显 ,其变化特征与 TDS 基本一致 ;水化学成分和类型在空间上呈现出由上游向下游过渡变化的分带特征 :从上游山区、中游盆地到下游的尾闾盆地 ,河水的水化学特征依次为HCO3 -型、SO42 --HCO3 -型和Cl-型 ;山区和山前冲洪积扇中地下水为低矿化度的HCO3 -型水 ,中游盆地地下水矿化度升高 ,水化学类型为HCO3 -或HCO3 --SO42 -,下游盆地地下水矿化度进一步升高 ,水化学类型为Cl--SO42 -或Cl-;垂向变化上 ,由浅层到深层地下水矿化度降低 ,水化学类型变化不大 ,中游盆地主要为HCO3 -和HCO3 --SO42 -;下游盆地主要为Cl--SO42 -。     

凉州区生态系统服务价值的变化

采用Constanza等的估测方法,利用1997～2006年凉州区土地变化数据,估算了凉州区生态系统服务价值变化特征.结果表明:1997～2006年间,凉州区生态系统服务价值总体呈上升趋势,土地利用变化保护了该区域生态系统的服务功能,使生态系统服务价值从1997年的25.32亿元增加到2006年的25.73亿元,增加0...     

气候变化对中国森林生态系统服务价值的影响

本文基于前人的研究成果 ,估算了三种气候变化情景下中国森林生态系统的服务价值 ,结果表明 :在当前和 ( 1 )年均温增加 4℃、降水增加 1 0 % ;( 2 )年均温增加 4℃、降水不变 ;( 3)年均温增加 4℃、降水减少 1 0 %气候变化情景下 ,中国森林的生态系统服务价值分别为 :2 70 7.2 5亿美元 ,4861 .45亿美元 ,4746.2 0亿美元和 4688.39亿美元。尽管在全球变暖背景下 ,中国的森林面积减少 ,但生态系统服务价值却明显增加。     

渭干河—库车河三角洲生态系统服务功能及敏感性分析

本研究利用渭干河-库车河三角洲绿洲1989年、2001年和2007年的遥感影像数据,分析了1989～2007年间研究区生态系统服务功能价值变化和生态系统敏感性.结果发现:在整个研究期内,研究区生态系统服务总价值呈下降趋势,从1989年的115.49×108元,分别下降为2001年的106.83×108元和2007年的94.47×108元;在生态系统各单项服务功能价值中,各单项服务功能差异显著,生态服务功能总体呈下降趋势.18 a来,水源涵养功能缺失最为明显,服务价值减少了4.64×108元,而食物生产功能变化最小,其价值增长仅为0.60×108元;同时,通过各单项服务功能在各研究阶段的价值变化情况来看,食物生产功能的生态服务价值增幅明显,水源涵养功能价值下降显著,而娱乐文化功能的价值变化最小;通过对生态系统敏感性指数分析,发现各景观生态系统敏感性指数都小于1,说明研究区生态系统服务总价值对生态价值系数是不敏感的,缺乏弹性.     

关中-天水经济区农田生态系统服务价值评价

生态系统服务价值作为一种潜在的经济效益,常被人们忽略,造成经济价值在无形中大量损失,本研究目的在于定量分析生态系统的服务价值。在GIS和RS的支持下,根据生态系统服务评价理论,采用生态经济学方法,计算2007年关中-天水经济区范围内农田生态系统的生态服务价值量。关中-天水经济区农田生态系统的总价值量为2.392×1012元,其中负价值为2.457×1011元,正负价值比例达10.88∶1。咸阳市的农田生态系统服务价值贡献率最大,占46%,其次是渭南市,占20%;渭南市的生态负价值贡献率最大,其次是铜川市。总体上看,关中-天水经济区农田生态系统服务价值呈现一定的空间区域差异,表现为平原服务价值高,山地服务价值低。服务价值高低主要受地势、综合地理条件、农业种植技术及环境污染程度的影响。     

陕西省耕地生态系统服务价值动态测评

为促进陕西省耕地可持续利用,中文采用耕地净第一性生产力测评模型和生态系统服务价值测评模型对陕西省耕地净第一性生产力、大气调节功能价值、涵养水源功能价值、水土保持功能价值和净化环境功能价值进行测评,并从省域和市域两个尺度分别探讨其动态变化特征。结果表明:1)2000～2009年陕西省耕地生态服务价值呈现上升趋势,10年共增加205.37亿元。各组分贡献率中,涵养水源价值贡献率最大,其次是水土保持价值,净化环境价值贡献率最小;2)从市域尺度分析,2000～2009年耕地生态服务价值增加最多的是榆林市,10年共增加96.95亿元;而减少最多的是安康市,10年共减少77.24亿元。从价值组分分析,大气调节价值增加最多的是榆林市,10年间共增加39.55亿元;水土保持价值增加较多的是西安市、延安市和榆林市,分别增加12.74亿元、10.7亿元和8.02亿元;涵养水源价值增加较多的是延安市和榆林市,分别增加31.23亿元和49.39亿元;而净化环境价值变化较小,除铜川市保持不变外,其余各市均呈小幅度减小趋势。     

渭干河-库车河三角洲绿洲景观格局动态变化及其对生态系统服务功能的影响

利用渭干河-库车河三角洲绿洲1989年、2001年和2007年的遥感影像数据,分析了1989～2007年间渭干河-库车河三角洲绿洲景观结构变化规律,并讨论了由此带来的生态系统服务价值的变化。结果发现:在1989年～2007年间,研究区林地、草地、盐碱地和水域在减少,其中林地减少最多,草地和盐碱地其次,水域面积减少最小。耕地、建设用地和沙砾在增加,耕地增加最多,建设用地其次,沙砾变化较小;在整个研究期内,研究区生态系统服务总价值呈下降趋势,从1989年的5744.1×106元,分别下降为2001年的5543.0×106元和2007年的4540.2×106元;在生态系统各单项服务功能价值中,气体调节、授粉、生物控制和食物生产所占比例在1989年～2007年间呈增长趋势,干扰调节、水分调节、营养循环和废物处理所占比例则在减少,气候调节、水分供应、侵蚀控制、原材料和休闲娱乐变化较小,土壤形成、栖息地、基因资源和文化服务所占比例则基本保持不变。     

辽河流域跨省界断面生态补偿共建共享帕累托改进研究

辽河流域生态补偿研究对防治辽河流域环境破坏具有重要意义。文中通过消除福利经济学帕累托相关的外部性来实现流域生态补偿帕累托改进,进而建立了辽河流域跨省界断面的生态补偿共建共享帕累托改进模型,选择2003-2010年辽河流域生态服务功能系统上游地区环境保护投入及上、下游地区的GDP数据,测算得到辽河流域可以通过对下游征税并对上游补偿或者谈判方法实现帕累托改进整体最优的补偿量范围可在32.63亿元和86.11亿元之间选择,明确了补偿前后辽河上、下游地区的福利变化,为辽河流域生态补偿提供了一种新的思路。     

Hymenopteran Parasitoids on Fruit-infesting Tephritidae (Diptera) in Latin America and the Southern United States: Diversity, Distribution, Taxonomic Status and their use in Fruit Fly Biological Control

We first discuss the diversity of fruit fly (Diptera: Tephritidae) parasitoids (Hymenoptera) of the Neotropics. Even though the emphasis is on Anastrepha parasitoids, we also review all the information available on parasitoids attacking flies in the genera Ceratitis, Rhagoletis, Rhagoletotrypeta, Toxotrypana and Zonosemata. We center our analysis in parasitoid guilds, parasitoid assemblage size and fly host profiles. We also discuss distribution patterns and the taxonomic status of all known Anastrepha parasitoids. We follow by providing a historical overview of biological control of pestiferous tephritids in Latin American and Florida (U.S.A.) and by analyzing the success or failure of classical and augmentative biological control programs implemented to date in these regions. We also discuss the lack of success of introductions of exotic fruit fly parasitoids in various Latin American countries. We finish by discussing the most pressing needs related to fruit fly biological control (classical, augmentative, and conservation modalities) in areas of the Neotropics where fruit fly populations severely restrict the development of commercial fruit growing. We also address the need for much more intensive research on the bioecology of native fruit fly parasitoids.     

Brief Guide for Authors

正Journal of Arid Land(JAL)is an international journal(ISSN 1674-6767;CN 65-1278/K)for the natural sciences,sponsored by the Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences and Science Press.It is published by Science Press and Springer-Verlag Berlin Heidelberg bimonthly.JAL publishes original,innovative,and integrative research from arid and semiarid regions,ad     

The parasitoid complex ofLiriomyza cicerina on chickpea (Cicer arietinum)

Liriomyza cicerina (Diptera: Agromyzidae) is an important pest on chickpea in Turkey. The objective of this study was to determine the parasitoids and rates of parasitism ofL. cicerina on chickpea (Cicer arietinum L.) during the 2005 and 2006 seasons in ?anl?urfa province, Turkey. Leaves with mines were sampled weekly and kept in the laboratory to observe and count emerging leafminer and parasitoid adults. Eight parasitoid species were collected: the braconidsOpius monilicornis Fischer andOpius tersus Foerster and the eulophidsDiaulinopsis arenaria (Erdös) andNeochrysocharis formosa (Westwood), which occurred in both the winter and summer seasons;Diglyphus crassinervis Erdös,Neochrysocharis ambitiosa Hansson,Neochrysocharis sericea (Erdös) andPediobius metallicus (Nees), which occurred only in the summer growing areas.Diaulinopsis arenaria was the predominant parasitoid with 4–7.7% parasitism rate whileN. ambitiosa andO. monilicornis were the second and third most predominant species. The results of these trials show that sinceDia. arenaria occurred throughout every season, it could potentially be used for control of the leafminerL. cicerina.     

Plant–herbivore asynchrony necessitates augmentative releases of the exotic beetle,Zygogramma bicolorata,to enhance the biological control of P arthenium hysterophorus

Systematic information on the quantitative impact of Z ygogramma bicolorata on the biology of P arthenium hysterophorus is crucial as the seeds of this weed continue to germinate from the accumulated soil seed bank throughout the year in the form of different germinating flushes, while the activity of the beetle ceases during winter as it enters diapause. Therefore, plant–herbivore interactions need to be explored to develop predictions of the overall impact of the introduced beetle on the weed. The findings revealed that defoliation by Z . bicolorata had a significant impact on the plant height, density and flower production in flushes F ₃, F ₄ and F ₅, but not in F ₁ and F ₂ that exhibited longer periodicity, profuse branching, a longer flowering period and maximum flower production and contributed mostly to the existing seed soil bank. Therefore, total depletion of the existing soil seed bank was not possible. Consequently, the effect of augmentative field releases of laboratory‐reared beetles was explored on F ₁ and F ₂ in February for three consecutive years (2011–2013). Before initiating the trial, random soil samples were taken from the plots that were assigned to the paired treatments (i.e. with the beetle and without the beetle [insecticide‐treated]) and it was found that the seed bank in those samples did not differ. The single release of Z . bicolorata adults at five per plant at the six‐leaf stage significantly reduced the soil seed bank, compared to without the biocontrol agent, irrespective of the flushes at the end of the season.     

Effects of the saprophytic leaf mycoflora on growth and productivity of winter wheat

The effects of the saprophytic mycoflora and its interference with cereal aphids on growth and yield of winter and spring wheat was studied in field experiments in 1980, 1981 and 1982.Yields varied between 5000 and 8000 kg dry matter of kernels per ha. The effect of the saprophytic mycoflora on yield was determined in different treatments: A) no control measures against cereal aphids and saprophytic and necrotrophic fungi, B) no control of cereal aphids, control of saprophytic and necrotrophic fungi, C) control of cereal aphids and control of saprophytic and necrotrophic fungi, D) control of cereal aphids and stimulation of saprophytic mycoflora and E) control of cereal aphids, no control of saprophytic and necrotrophic fungi nor stimulation of saprophytic mycoflora.Considerable differences in top densities of saprophytic mycoflora (10 times as large in A and D as in B and C) were determined. The consequences of these differences for the growth and productivity of wheat were minor. A negative effect of saprophytic mycoflora on the yield could not be detected in 1981 and 1982, whereas a small positive significant effect was found in 1980. This stimulation may have been due to competition between necrotrophic fungal pathogens and saprophytic mycoflora. As a result of favourable weather conditions necrotrophic fungal pathogens were very numerous in 1980 and could form an important yield reducing factor. Yield levels may effect the importance of the necrotrophic and saprophytic mycoflora as yield reducing factors. Additionally, in the presence of aphid honeydew captafol was found to be relatively ineffective against saprophytic fungi.     

Relationship Between Production of the Phytotoxin Prehelminthosporol and Virulence in Isolates of the Plant Pathogenic Fungus Bipolaris sorokiniana

A gas chromatographic method was developed to quantify the phytotoxin prehelminthosporol, which is a sesquiterpene metabolite of the plant pathogen Bipolaris sorokiniana. The toxin was extracted from mycelium or culture filtrates, pre-cleaned using solid phase extraction, and analyzed by gas chromatography as a trimethylsilyl-derivative. The detection limit of the method was 5ngl^–1 (signal to noise ratio 4:1) which corresponds to ca. 15ng prehelminthosporol per mg dry weight of mycelium or 15ng prehelminthosporol per ml culture filtrate. The total amount of prehelminthosporol (mycelium plus culture filtrate) increased with cultivation time when examined in six isolates of B. sorokiniana after 6, 9, 12 and 15 days of incubation. The screening experiment of 17 isolates for prehelminthosporol production after 8 days of incubation revealed significant differences in the toxin production between the isolates. The isolates with low toxin production had lower virulence towards barley roots compared to those with higher production of the toxin. However, the virulence did not increase with prehelminthosporol level among the high producing isolates. Prehelminthosporol was also analyzed in a number of related Bipolaris and Drechslera species. In addition to B. sorokiniana, three out of six Bipolaris species (B. setariae, B. zeicola, B. victoriae) produced prehelminthosporol, which indicates that ability to produce prehelminthosporol is conserved among closely-related Bipolaris species.     

Effect of botanical insecticides and bacterial toxins on the gut enzyme of the rice leaffolderCnaphalocrocis medinalis

The effect of botanical insecticides and bacterial toxins on gut enzyme activity of larvae of the rice leaffolderCnaphalocrocis medinalis (Guenée) (Insecta: Lepidoptera: Pyralidae) was investigated. Gut enzyme activities were affected by botanical insecticides and bacterial toxin individually and in combination. When fed a diet of rice leaves treated with botanical insecticides and bacterial toxins, in bioassays the activities of gut tissue enzymes — acid phosphatases (ACP), alkaline phosphatases (ALP) and adenosine triphosphatases (ATPase) — of rice leaffolder larvae were affected. When combined, the effect was more severe at a low concentration. Larvae that were chronically exposed to botanical insecticides and bacterial toxins showed a reduction in weight (59–89%) and exhibited a significant reduction in ACP, ALP and ATPase activities. The combination ofBacillus thuringiensis kurstaki and botanical insecticides caused a decrease of twofold in enzyme activity even at reduced concentration. A synergistic effect was found when botanical insecticides and bacterial toxins were combined at low doses. These effects were most pronounced in early instars. Clear dose-response relationships were established with respect to enzyme activity. In conclusion: (i) biopesticides are relatively safe and biodegradable; (ii) a synergistic effect of botanical insecticides and bacterial toxins was found; (iii) less expensive, readily available and naturally occurring biopesticides could be an alternative for organic and inorganic pesticides in controlling RLF. http://www.phytoparasitica.org posting Sept. 28, 2004.