采矿地的生态恢复技术_夏汉平VIP免费

采矿地的生态恢复技术＊夏汉平1＊＊蔡锡安2(1中国科学院华南植物研究所生态中心,广州510650;2云南农业大学农学院,昆明650201)【摘要】矿藏开采给生态环境带来严重破坏.矿地与尾矿的自然恢复是相当缓慢的,有些甚至是不大可能自然恢复的.本文总结了在过去20年全球发展起来的各种生态恢复技术措施,包括基质的改良,优良物种的选择等,并总结出一套人工恢复的一般步骤,分析了目前所存在的评判人工生态恢复成功与否的几种评价体系的优劣.关键词矿地尾矿生态恢复植物修复退化生态系统文章编号1001-9332(2002)11-1471-07中图分类号X171.5文献标识码AEcologicalrestorationtechnologiesforminedlands:Areview.XIAHanping1,CAIXi'an2(1SouthChinaInsti-tuteofBotany,ChineseAcademyofSciences,Guangzhou510650;2SchoolofAgronomy,YunnanAgricultur-alUniversity,Kunming650201).-Chin.J.Appl.Ecol.,2002,13(11):1471～1477.Miningactivitiesusuallycausecatastrophicandextensiveenvironmentalchanges,andeventuallycausemajordamagestothewholeecosystem.Thenaturalrestorationforminelandsandtailingsisaveryslowprocess,andevencanhardlyreachtheiroriginalstates.Therefore,howtodeveloprapidandefficientapproachestoacceleraterestorationofminedlandshasbeenhighlightedbyrestorationistsandenvironmentalengineersduringthepasttwodecades.Almostallstudiesinthisfieldindicatethatthemajorproblemscomefromsoils:suchashighmetalconcentrations,extremelystrongacidityresultingfromoxidationofpyrite,andpoorfertility.Replacementoftopsoilisthereforeregardedasthemostefficientmethodtoalleviateadverseconditionsofsubstrates;ifthismethodisnotavailable,otheralternativeswithlime,fertilizers,organicmanures,garbage,miningwastes,andotherswillbeapplicable.Intheaspectofusingplants,specieswithstrongresistanceandrapidgrowth,likegrassesandherbaceouslegume,arealwaysthefirstchoice.Ifutilizingplantsforthepurposeofphytoreme-diation,speciesthatarecapableofaccumulatingexceptionallyhighconcentrationsofphytotoxicmetalsandofcourse,haveahugebiomass,arepreferablyconsidered.Nomatterwhattypeofecosystemaminedlandisre-storedorreclaimedto,anevaluationonwhetheritisasuccessfulrestorationorreclamationshouldbegiven.However,morepractical,simple,anduniversalevaluationmethodsaswellasmorecost-effective,andoperation-easyrestorationtechniquesarestillwaitingtobedeveloped.Asetofartificialrestorationmethodsthatcanbewidelyappliedwassummarized,andadiscussionontheadvantageanddisadvantageofseveralevaluationsystemswasconductedinthisreview.KeywordsMineland,Minetailings,Ecologicalrestoration,Phytoremediation,Degradedecosystem.＊国家自然科学基金(39870155)与广东省自然科学基金资助项目(980479).＊＊通讯联系人.2001-09-21收稿,2002-03-15接受.1引言人类从事采矿业已有数千年的历史,开采矿藏给人类带来了巨大财富,但是采矿过程所导致的环境污染与破坏以及采后留下的尾矿、废弃地、废渣等都带来了许多生态环境问题.这些环境问题集中起来主要表现在以下几个方面:1)生态景观遭破坏.通常,一个矿地在开采之前都是森林、草地或植被覆盖的山体.一旦开采后,植被消失,山体遭破坏,矿渣与垃圾堆置,最终形成一个与周围环境完全不同甚至极不协调的外观[62].2)土壤基质被污染.重金属毒害是矿地普遍存在且最为严重的问题之一,如广东凡口铅锌尾矿1号矿的Pb,Zn总量分别高达34300和36500mg·kg-1,有效态Zn亦高达1963mg·kg-1[37,39].如此高的金属含量对绝大多数植物的生长发育都产生严重抑制和毒害作用[37,57].尾矿另一个常见的污染是高度酸化,主要是由于硫铁矿(FeS2)或其他金属硫化物氧化所致.例如,Pb/Zn矿的S含量高达15.4%,酸化后能使基质的pH降至2.4左右[72,77];渗出液甚至降至2左右[22].高含量的重金属与强的酸度通常是植物在矿地定居的最大限...