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1.
矿区常见乔木叶片重金属特征及其修复应用   总被引:2,自引:0,他引:2  
对广西河池大厂矿区内的植被和立地条件进行调查分析,旨在寻找一些可用于植物生态修复重金属污染的乔木,并估算其去除重金属的能力。在调查区内设立了3个村屯采样点,对常见树木,如沙梨(pyrus pyrifolia(burm·f.)nakai)、板栗(Castaneamollissima Blume)、拐枣(Hovenia acerba)、柚子树(Citrus maxima)、银杏(Ginkgo biloba)、樟树(Cinnamomum camphora)、柿子树(Diospyros kaki)和枇杷(Eriobotrya japonica)等8种植物叶片及周围表层土壤进行采样,检测叶片和土壤中重金属总量(Mn、Zn、Cu、As、Cd、Sn、Sb、Pb)。对植物叶片采用ICP-MS及ICP-AES进行测定,土壤的重金属用ICP-AES进行检测。结果发现表土重金属含量均超过广西土壤背景值的5-1200倍,其中Cd污染最严重,为背景值的1200多倍。3个采样点位之间及同一采样点内不同植物叶片对重金属的吸收无显著性差异(Mn除外),8种植物叶片固定重金属的范围如Cu为3.331 9 mg·kg-1-10.885 1 mg kg-1,As为1.7811 mg·kg-1-46.217 8 mg·kg-1,Cd为0.046 55 mg·kg-1-4.989 7 mg·kg-1;其中拐枣树叶对Mn有较高吸收,分别达811.11 mg·kg-1,352.31 mg·kg-1,220.11 mg·kg-1。以生物量估测模式计算的屯一8种植物单株叶片总量对重金属的总吸收量,单株拐枣叶总量可吸收21.25 g Mn、3.003 g Zn、0.20 g Cu、0.28 gAs、0.066 g Cd,、0.014g Sn、0.17 g Sb和1.23 g Pb,而单株樟树叶可吸收1.55 g Mn、0.79 g Zn、0.17 g Cu、0.12 g As、0.011 g Cd、0.017 g Sn、0.14g Sb和0.40 g Pb。但所调查果树中的梨树和板栗树单株叶总量吸收重金属也较高,梨可吸收2.90 g Mn、3.32 g Zn、0.57 g Cu、0.11 g As、0.043 g Cd、0.014 g Sn、0.13 g Sb和0.79 g Pb;而板栗则吸收99.82 g Mn、5.20 g Zn、0.28 g Cu、0.24 g As、0.048g Cd、0.017 g Sn、0.26 g Sb和0.94 g Pb。但这些果树存在食品安全风险,故建议选择拐枣和樟树作为该矿区的植物修复的优选树种。  相似文献   

2.
续断菊与玉米间作系统不同植物部位Cd、Pb分配特征   总被引:4,自引:0,他引:4  
采用植物修复的方法对会泽铅锌矿周围受Cd、Pb污染的农用地进行修复,将超富集植物续断菊和农作物玉米在污染农用地间作种植,以减少农用地重金属含量,并获得合格的农产品。通过田间小区直接种植的方式,测定植物生物量及各器官重金属含量,研究续断菊(Sonchus asper L.Hill)与玉米(Zea mays L.)间作系统植物不同器官Cd、Pb分配特征。结果表明,(1)间作续断菊生物量相比单作增加了31.55%,间作玉米生物量相比单作增加了29.02%。(2)从拔节期到成熟期,间、单作玉米各器官Cd质量分数呈下降趋势。成熟期与拔节期相比,间作玉米根、茎、叶Cd质量分数分别降低了24.51%、29.06%、55.32%,单作玉米根、茎、叶Cd质量分数分别降低了22.05%、7.20%、45.02%。在不同时期,间作玉米根、叶Cd质量分数都低于单作玉米根、叶Cd质量分数。根部Cd质量分数在抽穗期和成熟期差异显著;叶部Cd质量分数在成熟期差异性显著;茎部Cd质量分数在抽穗期和成熟期呈现出单作大于间作,在成熟期差异显著。玉米各部位Pb质量分数呈现出先增加后下降趋势,且成熟期根、茎Pb质量分数小于拔节期,而该期叶Pb质量分数则大于拔节期。不同时期,间作玉米根、叶Pb质量分数小于单作玉米根、叶,根在抽穗期和成熟期Pb质量分数差异性显著;间作玉米籽粒Cd、Pb质量分数显著小于单作。(3)续断菊根部及地上部Cd质量分数随时间推移而呈现逐渐增加趋势,间作续断菊根部及地上部Cd质量分数分别增加16.88、15.45 mg·kg-1,单作续断菊根部及地上部Cd质量分数分别增加5.5、10.09 mg·kg-1,间作续断菊地上部Cd质量分数显著大于单作,间作根部大于单作根部,在抽穗期和成熟期出现显著差异。(4)间作、单作种植模式下土壤Cd、Pb质量分数均有下降,土壤Cd质量分数在间作模式下降25.99%,单作续断菊模式下降23.19%,单作玉米模式下降14.78%;土壤Pb质量分数在间作模式下降6.78%,单作续断菊模式下降7.53%,单作玉米模式下降7.23%。结果表明,续断菊和玉米间作促进了续断菊各部位对镉的积累量,同时抑制了玉米各部位镉的积累量。  相似文献   

3.
采用盆栽试验,研究新型生物可降解螯合剂冬氨酸二丁二酸醚(AES)和非降解螯合剂乙二胺四乙酸(EDTA)调控下黑麦草修复重金属污染土壤的效应.黑麦草于含2500 mg Pb·kg-1,500 mg Cu·kg-1,1000 mg Zn·kg-1 和15 mg Cd·kg-1 的土壤中生长45d后,分别施加5 mmol·kg-1 土的AES或EDTA.结果表明,AES和EDTA可以显著提高土壤溶液和黑麦草植株地上部Pb、Zn、Cu和Cd的浓度.EDTA对土壤中Pb的溶解能力和对黑麦草积累重金属的促进作用显著强于AES,前者处理的土壤中水提取态Pb浓度和黑麦草地上部Pb浓度分别达到了15.9 mg·kg-1 和174.1 mg·kg-1,显著高于AES处理的2.6 mg·kg-1 和44.0 mg·kg-1.但AES对黑麦草积累Zn和Cd的促进作用较EDTA明显增强,黑麦草地上部Zn浓度达到了1081.8 mg·kg-1,显著高于EDTA的776.7 mg·kg-1 和对照的389.6 mg·kg-1;地上部Cd浓度为1.57mg·kg-1,高于EDTA的1.06 mg·kg-1 和对照的0.69 mg·kg-1.与对照相比,AES和EDTA对Cu在土壤中的溶解和黑麦草植株中的积累亦有显著的促进作用,但二者处理无极显著差异.结果表明,生物可降解螯合剂AES在诱导植物修复重金属污染土壤尤其是Zn、Cd污染土壤中有很大的应用潜力,且与EDTA相比,环境风险大大降低.  相似文献   

4.
不同生态型芦竹对Cd、Hg、Pb、Cu的富集与分布   总被引:11,自引:0,他引:11  
韩志萍  王趁义 《生态环境》2007,16(4):1092-1097
介绍了生态型芦竹(Arundo donax Linn)的生物特性,并对芦竹修复湿地重金属污染能力进行了研究。芦竹具有生物量大、根系发达、适应性强等特点,在重金属污染环境下,有较好的耐受性。研究不同生态型芦竹对Cd、Hg、Pb、Cu的富集与分布,对重金属污染湿地的修复具有指导作用。采集了4个不同环境下的芦竹样本,对重金属富集量和在植物器官中的分布情况进行研究分析。结果表明,芦竹对镉、铅、汞有较好吸收,地上部叶内富集量分别为57.40~33.22mg·kg-1,412.4~312.4mg·kg-1,21.5~11.8mg·kg-1,地上部茎内富集量分别为19.50~4.02mg·kg-1,83.1~43.6mg·kg-1,30.0~19.4mg·kg-1。芦竹对铜的富集能力较弱,地上部叶内和茎内富集量分别是12.4~2.8mg·kg-1,1.4~0.4mg·kg-1。铜和铅在植物器官中的分布为根>叶>茎,镉在植物器官中的分布为叶>根>茎,汞在植物中的分布为根>茎>叶。富集量还与土壤中重金属质量分数有关,一般是随着土壤中重金属质量分数的增大而增加。镉、铅、铜在植物叶中的富集系数大于1,汞在植物茎中的富集系数大于1。综合分析结果表明,芦竹在污染或非污染环境中都能较好地富集镉、铅、汞,基于芦竹具有较大生物量特点,芦竹对湿地重金属污染具有较大的修复潜力。研究芦竹对重金属的吸收与分布,旨在为湿地的植物修复技术提供参考依据。  相似文献   

5.
外来植物紫茎泽兰(Eupatorium adenophorum)入侵我国西南地区并造成了严重的生态灾难,通过研究Pb、Cd及其复合污染对紫茎泽兰生长及吸收富集特征的影响,有助于从生态学角度为紫茎泽兰的综合防控提供依据。采用模拟Pb、Cd污染土壤培养法研究了不同浓度Pb、Cd及其复合污染作用下紫茎泽兰的生长响应及重金属吸收、富集和迁移特征变化。结果表明:低浓度的Pb、Cd对紫茎泽兰的生长有促进作用,高浓度则表现出一定的抑制作用,生物量,株高,根长均明显减少。紫茎泽兰体内Pb、Cd吸收量与污染土壤具有良好的相关性,随处理浓度增加明显增大,极端浓度Pb、Cd胁迫下紫茎泽兰各器官Pb、Cd积累量与对照相比显著增加,1000 mg·kg-1处理时紫茎泽兰根、茎、叶的Pb质量分数均分别高达603.69、568.31、598.85 mg·kg-1;100 mg·kg-1 Cd处理时其根、茎、叶的Pb、Cd累积量依次为165.21、93.59、152.79 mg·kg-1。说明紫茎泽兰对Pb、Cd具有较好吸收累积及转运能力,可作为重金属污染地区的一种理想的修复植物。  相似文献   

6.
成都平原表层水稻土重金属污染健康风险分析   总被引:8,自引:0,他引:8  
杨刚  李燕  巫林  谢丽苹  伍钧 《环境化学》2014,(2):269-275
采样分析了成都平原表层水稻土(0—20 cm)中As、Cd、Cr、Hg、Pb、Cu、Zn含量,参照国家土壤环境质量标准和土壤背景值,并利用健康风险评价模型对土壤重金属环境质量状况和人体健康风险进行了评价.结果表明,成都平原水稻土表层7种重金属平均含量分别为As:9.69 mg·kg-1、Cd:0.12 mg·kg-1、Cr:79.5 mg·kg-1、Hg:0.04 mg·kg-1、Pb:47.5 mg·kg-1、Cu:29.3 mg·kg-1、Zn:81.7 mg·kg-1.与成都地区土壤背景值相比,As、Cr、Pb、Cu、Zn在表层水稻土中有明显积累,部分样区土壤重金属超过《土壤环境质量标准》(GB15618—1995)标准值的二级标准,存在外源污染输入,但污染程度较轻.人体健康风险分析结果表明,经土壤-口接触行为摄入是该区域人体重金属暴露风险的主要途径,重金属致癌风险AsCd,非致癌总风险CrCuHgPbZn,无论儿童还是成人,重金属致癌风险值和非致癌风险值均低于风险阈值,风险值均在可接受水平内,但儿童健康风险值高于成人,应加强监管.  相似文献   

7.
滇南矿区重金属污染耕地的植物修复及其健康风险   总被引:3,自引:0,他引:3  
在云南个旧矿区大田种植条件下,研究种植蜈蚣草、鲜食糯玉米、板蓝根蔬菜和高梁对重金属As(103.83±4.30)mg·kg~(-1)、Pb(293.17±15.99)mg·kg~(-1)、Cd(1.95±0.16)mg·kg~(-1)复合污染土壤的治理和修复效果,并分析作物对人体的健康风险。结果表明,4种植物对土壤重金属的吸收有较大的差异,蜈蚣草As富集系数为(1.74±0.16),表现出较好的As富集植物特性,Pb富集系数为(0.42±0.05),富集能力明显高于其它3种植物。高梁秸杆、玉米秸杆、板蓝根蔬菜Cd富集系数均大于1,尤其是板蓝根蔬菜,富集系数为(3.19±0.46),Cd富集能力较强;在生物量和重金属吸收量的双重作用下,高梁秸杆对土壤中As、Pb、Cd的提取效率均高于其它3种植物。蜈蚣草除Cd外,对土壤重金属As、Pb的提取效率与高梁相当;经公式计算,若通过种植以上4种植物将试验区土壤As、Pb、Cd修复到国家土壤环境质量二级标准限量以内,需要种植玉米和板蓝根蔬菜约100年以上,而种植高梁仅需25年。蜈蚣草对试验区土壤As、Pb修复效果明显,预计种植蜈蚣草30年可将试验区土壤As、Pb修复到国家土壤环境质量二级标准限值以内;参试的3种可食用作物健康风险分析表明,当地居民通过食用板蓝根蔬菜进入人体的Pb、As和Cd暴露风险指数(HQ)均大于1,人体健康风险较大,不宜在试验区种植食用;食用玉米、高粱进入人体的Pb、As和Cd暴露风险指数虽小于1,但Pb和As的HQ均在0.9以上,存在潜在的健康风险。综合分析4种植物的修复效果、健康风险以及经济效益,高梁作为一种优良的生物质能源植物,引导种植较高抗性的高梁品种以及套种低累积高梁品种与蜈蚣草,可推荐作为滇南矿区重金属复合污染耕地边生产、边修复的土地安全利用模式。  相似文献   

8.
三明铅锌矿区植物对重金属的富集特征   总被引:7,自引:0,他引:7  
采用野外调查与室内分析相结合的方法,对福建三明典型矿区尤溪铅锌矿、大田铅锌矿以及尤溪铅锌矿冶炼厂等进行了调查,研究这些矿区重金属含量较高的区域如采矿区、尾砂库、洗矿排水沟以及铅锌矿冶炼厂厂区和排水沟冲积扇区域土壤中的Pb、Zn和Cd的含量,在此基础上,对在这些区域自然定居的16种优势植物体内的三种重金属元素的耐性、富集特性进行了分析。结果表明:该矿区的主要优势物种为禾本科和菊科植物,其中笔管草(Equisetum ramosissimum)、一年蓬(Erigeron annuus)和五节芒(Miscanthus floridulus)的地上部重金属富集量较大,对矿区周边污染土壤修复有潜在应用价值;乌蕨(Stenoloma chusana)、千金子(Bochloe dactyloides)、二歧飘拂草(Fimbristylis dichotoma)、柔枝莠竹(Microctegium Vimineum)、短叶水蜈蚣(Kyllinga brevifolia)、狗娃花(Heteropappus hispidus)适用于污染程度较高且植物萃取技术难以实施的重金属污染矿业废弃地。矿区植物地上部Zn含量平均值最高,为1225.74mg·kg-1,植物地上部Pb含量范围在52.78~2137.11mg·kg-1,平均为521.39mg·kg-1;一年蓬地上部Cd含量达到了119.51mg·kg-1,超过了超富集植物的临界值100mg·kg-1,转运系数为1.3,是潜在的Cd超富集植物。  相似文献   

9.
植物激素可打破重金属超富集植物的种子休眠、促进发芽和快速生长,从而提高其富集重金属的效率。虽然人工合成的植物生长调节剂在促进超富集植物生长和提高重金属富集方面已取得很多成果,但大多是盆栽试验,大田试验甚少。文章在课题组前期室内盆栽试验筛选出的吲哚乙酸(IAA)和激动素(KT)提高砷(As)超富集植物蜈蚣草(Pteris vittata L.)砷提取效率的最佳配比(IAA:KT=25 mg·L~(-1):20 mg·L~(-1))基础上,在云南省个旧市大屯镇重金属污染农田分45个小区、喷施2次激素开展IAA和KT配合施用对As超富集植物蜈蚣草和镉(Cd)超富集植物龙葵(Solanum nigrum L.)超富集As和Cd的影响和机理研究。结果表明,大田条件下IAA和KT配合施用能够促进2种超富集植物快速生长,在含Cd为3.12 mg·kg~(-1)、含砷As 98.7 mg·kg~(-1)的农田土壤上,与未施用植物激素的对照相比,25 mg·L~(-1) IAA和20 mg·L~(-1) KT配合施用后,龙葵和蜈蚣草的株高、鲜物质量、地上部和地下部Cd/As含量、Cd/As转运系数和富集系数均显著增加,且龙葵对Cd、蜈蚣草对As的提取效率最高可分别达7.52%和6.06%。第2次喷施激素后,单加KT和激素配合施用条件下,龙葵和蜈蚣草间作时两种植物叶片过氧化物酶(POD)活性均显著增加。逐步回归分析结果表明,龙葵对As、蜈蚣草对Cd的提取效率均与叶片POD活性成显著正相关。因此,叶片保持较高的POD活性对两种超富集植物对Cd和As的提取具有重要意义。  相似文献   

10.
以天津市郊农田土壤为研究对象,采集东丽、西青、津南和北辰4区水浇地、旱地和园地3种土地利用类型的327个土壤表层(0~20 cm)样品,分析测定土壤中As、Pb、Cd、Cr和Ni 5种重金属含量。结果表明,天津市郊农田土壤重金属As、Pb、Cd、Cr和Ni平均含量依次为10.01、33.71、0.32、56.95和33.50 mg·kg~(-1),除Cr含量外其他重金属元素含量均高于天津市土壤环境背景值,呈现一定的积累特征。以GB 15618—2018《土壤环境质量农用地土壤污染风险管控标准(试行)》为评价标准,As、Pb、Cd、Cr和Ni 5种重金属元素中仅Pb、Cd和As超标,超标率分别为3.06%、14.07%和0.31%,表明天津市郊一些农田土壤存在Cd污染,个别农田土壤存在Pb和As污染,其余重金属元素对农田土壤造成污染的风险很低。采用单因子污染指数法和内梅罗综合污染指数法对农田土壤重金属污染程度进行评价,结果表明,天津市郊土壤Cd污染处于警戒限水平,按区域划分,Cd在东丽区存在一定污染,按不同土地利用类型划分,Cd在园地存在一定污染,其余重金属元素均处于安全水平。总体而言,天津市郊农田土壤除了存在一定程度的Cd污染外,其他各重金属污染风险较低。  相似文献   

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Environmental Chemistry Letters - Chitosan is a biopolymer obtained from chitin, one of the most abundant and renewable materials on Earth. Chitin is a primary component of cell walls in fungi, the...  相似文献   

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Hair samples were collected randomly from 110 subjects (55 male and 55 female) ranging in age from (<15–60) years. Each subject was asked to complete a personal questionnaire describing his/her sex, age, general health, smoking, use of hair dyes, occupational area, and living habits. Concentrations of Pb, Cd, Cu, Zn, Fe, and Ca in human hair samples were evaluated using atomic absorption spectrometry. Results indicated that concentrations of Pb, Cd, Cu, and Zn in the hair of smokers were higher than those in the hair of non-smokers, whereas, Fe and Ca concentrations in hair of smokers were lower than those in hair of non-smokers. Moreover, the concentrations of these elements are higher in dyed hair compared with undyed hair.  相似文献   

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For the transition metals chromium, nickel, iron, copper, cobalt, platinum, and molybdenum, mechanisms of stable bonding in biochemistry (emphasis on carcinogenic mechanisms), chemistry, industrial chemistry, as well as epidemiological, occupational, orthopedic (implant devices) effects related to carcinogenesis, were reviewed. Hypothetically, the propensity to stable bonding (inertness), which ensures the metals’ performance capacity for consumers and industrial application, relates to their carcinogenicity. For chromium, a relationship between industrial/chemical and biological reactivity was noted for the tendency of Cr(III) ions to cause hydrolysis previous to stable bonding, as occurs during anodic passivation, leather tanning, and as indicated in biochemical studies pertaining to a mechanism of DNA condensation, which was suggested as a carcinogenic mechanism. The involvement of metal hydrolysis in both anodic passivation and biochemistry was noted also for nickel, iron, and platinum; the DNA interaction of platinum (cis-platin) is known to depend on hydrolysis. For nickel, issues of potential (V) were found important in both passivation and carcinogenicity. Comparably, the passivity behavior of cobalt and copper was found atypical, and their carcinogenicity yet unclear. Molybdenum, contained in passivated metallic implants, may relate to implant-associated carcinogenesis. Occupational carcinogenic effects were indicated for chromium, nickel, iron, and cobalt as caused by both reactive and passivated metal species. Exposure to acids and chronic respiratory irritation/infection/inflammation in workers were important cofactors in metal carcinogenesis. For wood and leather workers exposed to dust, the assumed presence in dust of metal particles abraded from alloys (sawing or cutting blades) may be a carcinogenic exposure hazard.  相似文献   

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The development and recycling of biomass production can partly solve issues of energy, climate change, population growth, food and feed shortages, and environmental pollution. For instance, the use of seaweeds as feedstocks can reduce our reliance on fossil fuel resources, ensure the synthesis of cost-effective and eco-friendly products and biofuels, and develop sustainable biorefinery processes. Nonetheless, seaweeds use in several biorefineries is still in the infancy stage compared to terrestrial plants-based lignocellulosic biomass. Therefore, here we review seaweed biorefineries with focus on seaweed production, economical benefits, and seaweed use as feedstock for anaerobic digestion, biochar, bioplastics, crop health, food, livestock feed, pharmaceuticals and cosmetics. Globally, seaweeds could sequester between 61 and 268 megatonnes of carbon per year, with an average of 173 megatonnes. Nearly 90% of carbon is sequestered by exporting biomass to deep water, while the remaining 10% is buried in coastal sediments. 500 gigatonnes of seaweeds could replace nearly 40% of the current soy protein production. Seaweeds contain valuable bioactive molecules that could be applied as antimicrobial, antioxidant, antiviral, antifungal, anticancer, contraceptive, anti-inflammatory, anti-coagulants, and in other cosmetics and skincare products.

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• Microplastics are widely found in both aquatic and terrestrial environments. • Cleaning products and discarded plastic waste are primary sources of microplastics. • Microplastics have apparent toxic effects on the growth of fish and soil plants. • Multiple strains of biodegradable microplastics have been isolated. Microplastics (MPs) are distributed in the oceans, freshwater, and soil environment and have become major pollutants. MPs are generally referred to as plastic particles less than 5 mm in diameter. They consist of primary microplastics synthesized in microscopic size manufactured production and secondary microplastics generated by physical and environmental degradation. Plastic particles are long-lived pollutants that are highly resistant to environmental degradation. In this review, the distribution and possible sources of MPs in aquatic and terrestrial environments are described. Moreover, the adverse effects of MPs on natural creatures due to ingestion have been discussed. We also have summarized identification methods based on MPs particle size and chemical bond. To control the pollution of MPs, the biodegradation of MPs under the action of different microbes has also been reviewed in this work. This review will contribute to a better understanding of MPs pollution in the environment, as well as their identification, toxicity, and biodegradation in the ocean, freshwater, and soil, and the assessment and control of microplastics exposure.  相似文献   

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Specimens of oceanic decapods, mysids and euphausiids, collected from the North East Atlantic Ocean during July 1985, were analysed for V, Cr, Mn, Fe, Ni, Co, Cu, Zn, As and Cd. Measurement of the metals was carried out using two techniques: inductively-coupled plasma-source mass spectrometry (ICP-MS) and atomic absorption (AAS). With the exception of the iron data, good agreement was observed between the data from the two techniques. Baseline-metal data are presented for the species measured, along with any effects of animal size on metal concentration. The data presented for oceanic animals from different trophic levels are important in studies of metal fluxes and for the assessment of markers within the food web in the oceans.  相似文献   

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Results from populations of insects and birds inhabiting Phragmites habitats were used to analyze effects of fragmentation. Flush-crash cycles of the stem-boring moth Archanara geminipuncta (Lepidoptera, Noctuidae) showed regionally concurrent, local extinctions despite an originally enormous population size (more than 180,000 adults), emphasizing the importance of metapopulation dynamics. Further, A. geminipuncta could be considered a keystone species, since shoot damage facilitated more than twenty species of herbivores, saprovores (of the caterpillars' feces), and their parasitoids. The gall midge Lasioptera arundinis could survive only in side shoots induced by shoot damage of A. geminipuncta .
Small Phragmites stands had thinner shoots (due to a water or nutrient deficiency) and shoots with more leaves (due to a better light supply) than large stands, thereby influencing species-specific demands for habitat suitability and nutritiousness of reed tissue. In other words significance of habitat fragmentation could not be assessed by area alone. For example, two chloropid flies depending on thin, yellowish shoots survived only in small habitats or in the unmown edges of large habitats.
Local persistence of Phragmites herbivores depended on much larger population sizes than could be expected from a population size sufficient to maintain genetic variation. At least 11,000 adults of the gall midge Giraudiella inclusa (or more than 84,000 galls) were necessary to avoid local extinction.
With regard to conservation management of reed habitats, nature reserves should consist of old and unmown reeds, have fewer disturbed (particularly, fewer mown) habitat edges, measure more than two hectares (priority should go to the largest remaining fragments), and be surrounded by nearby reed habitats providing reservoir populations and diverse shoot types.  相似文献   

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