烏梁素海生態(tài)功能定位初步分析.doc

烏梁素海生態(tài)功能定位初步分析付新峰1, 2*作者簡(jiǎn)介：付新峰（1977），男，河南周口人，博士，工程師。主要從事水文水資源與水生態(tài)方面研究。Email:，谷曉偉1，劉曉巖3，何宏謀1（1黃河水利科學(xué)研究院鄭州450003; 2 北京師范大學(xué)，地理學(xué)與遙感科學(xué)學(xué)院北京100875; 3 黃委會(huì)水文局鄭州450004）摘要：烏梁素海是由黃河改道形成的河跡湖，中國(guó)八大淡水湖之一，對(duì)維護(hù)流域濕地生態(tài)平衡，保護(hù)物種的多樣性起著舉足輕重的作用。其生態(tài)環(huán)境惡化直接影響到區(qū)域糧食安全，并威脅到黃河中下游水資源安全。根據(jù)烏梁素海在黃河流域所處的位置，從生態(tài)修復(fù)的角度，明確烏梁素海的生態(tài)定位。即濕地生態(tài)功能定位、防洪防凌功能定位、黃河水資源安全功能定位、生態(tài)與環(huán)境保護(hù)功能定位、景觀生態(tài)功能定位與生態(tài)服務(wù)功能定位等六個(gè)方面。從而對(duì)各生態(tài)功能定位進(jìn)行初步分析論證。關(guān)鍵詞：烏梁素海；濕地；生態(tài)定位；生態(tài)功能1引言烏梁素海位于內(nèi)蒙古巴彥淖爾市烏拉特前旗境內(nèi)，西臨河套灌區(qū)，東靠烏拉山，是內(nèi)蒙古自治區(qū)較大的湖泊之一12。湖形為北寬南窄，東北至西南較長(zhǎng)，約35km，寬約412km3。現(xiàn)狀烏梁素海水面面積224.3km2，平均水深0.7m，水面高程為1018.6m，蓄水總量達(dá)24億m3。烏梁素海是由黃河改道形成的河跡湖，中國(guó)八大淡水湖之一，也是全球荒漠半荒漠地區(qū)極為罕見的具有生物多樣性和環(huán)保多功能的大型草原湖泊，對(duì)維護(hù)世界性的生態(tài)平衡，保護(hù)物種的多樣性起著舉足輕重的作用。烏梁素海不僅蘊(yùn)含著巨大的水生植物、漁業(yè)、鳥類和旅游業(yè)等資源，在我國(guó)北方地區(qū)承擔(dān)著重要的生態(tài)屏障作用，同時(shí)，現(xiàn)有水域還是確保黃河內(nèi)蒙古河段枯水期不斷流的主要水源補(bǔ)給庫(kù)，也是黃河汛期、凌期以及當(dāng)?shù)鼐值乇┯甑臏閹?kù)，對(duì)于維系黃河水系具有巨大的不可替代的作用。烏梁素海是河套灌區(qū)的重要組成部分，它接納了河套地區(qū)90%以上的農(nóng)田排水，然后經(jīng)過(guò)湖泊的生物生化作用后，排入黃河，客觀上起到改變水質(zhì)、調(diào)控水量、控制河套地區(qū)鹽堿化等關(guān)鍵作用，減少了農(nóng)業(yè)排水對(duì)黃河水質(zhì)的直接影響。烏梁素海還是我國(guó)北方重要候鳥遷徙和繁衍地，擁有的180多種鳥類中屬國(guó)家一、二級(jí)保護(hù)動(dòng)物的珍稀鳥類就達(dá)30多種，對(duì)保護(hù)物種多樣性起著不可替代的作用，有資料記載，烏梁素海是全球半荒漠地區(qū)極為少見的具有很高生態(tài)效益的大型多功能湖泊4。由于該地區(qū)近年來(lái)工業(yè)化、城鎮(zhèn)化進(jìn)程的加速帶來(lái)的工業(yè)廢水及城鎮(zhèn)生活污水以及農(nóng)業(yè)退水的大量排放和湖泊自身因素的影響，導(dǎo)致湖泊富營(yíng)養(yǎng)化嚴(yán)重，水域生態(tài)環(huán)境惡化1，突出的表現(xiàn)：一是總磷、總氮嚴(yán)重超標(biāo)，水體中營(yíng)養(yǎng)物質(zhì)過(guò)多，富營(yíng)養(yǎng)化問(wèn)題嚴(yán)重；二是水生植物過(guò)量生長(zhǎng)，沼澤化趨勢(shì)加??；三是湖泊周圍水土流失嚴(yán)重，湖體萎縮加速；四是水源減少，水位下降迅速。所有這些不僅影響湖泊整體功能發(fā)揮，還直接影響到區(qū)域糧食安全，并威脅到黃河中下游供水安全。烏梁素海的水生態(tài)環(huán)境問(wèn)題已經(jīng)成為該地區(qū)乃至整個(gè)內(nèi)蒙古自治區(qū)經(jīng)濟(jì)社會(huì)可持續(xù)發(fā)展的制約因素。因此，從生態(tài)修復(fù)的角度明確烏梁素海的六個(gè)方面的生態(tài)定位，為烏梁素海的生態(tài)保護(hù)與修復(fù)指明了方向，具有極為重要的實(shí)際意義，同時(shí)作為維持黃河健康生命理論與實(shí)踐的一部分，發(fā)揮著重要的生態(tài)功能。2烏梁素海生態(tài)功能定位2.1濕地生態(tài)功能定位（1）清除污染的功能烏梁素海濕地是水資源的“貯存庫(kù)”和“凈化器”。濕地具有強(qiáng)大的水文調(diào)節(jié)和循環(huán)功能，可以有效貯存、滯留降水和地表徑流，并補(bǔ)充地下水。濕地還具有強(qiáng)大的降解污染和凈化水質(zhì)功能。烏梁素海濕地土壤及生存于其中的多樣的植物群落、微生物群落，具有吸附、吸收和分解污染物，凈化環(huán)境的功能，它們?cè)谌コ龖腋∥?，促進(jìn)營(yíng)養(yǎng)物質(zhì)循環(huán)，產(chǎn)生O2等方面亦有重要作用，因而烏梁素海濕地被喻為巴彥淖爾的“自然之腎”。烏梁素海濕地中有蘆葦?shù)仍S多水生植物在其組織中富集重金屬的濃度大大高于周圍水體中的濃度。沼澤中的蘆葦對(duì)污染物質(zhì)具有吸收、代謝、積累及其對(duì)污水凈化作用。烏梁素海水面面積與蘆葦覆蓋總面積達(dá)346km2，水量24億m3，具有較為強(qiáng)大的清除污染的功能56。（2）氣候調(diào)節(jié)的功能烏梁素海濕地也是重要的“儲(chǔ)碳庫(kù)”和“吸碳器”。2001年衛(wèi)星遙感影像解譯結(jié)果表明其中明水面面積為167.6 km2，天然生長(zhǎng)的蘆葦覆蓋面積為146 km2，加上生長(zhǎng)在廢棄農(nóng)田上的蘆葦?shù)兀淇偯娣e達(dá)346km2，烏梁素海是內(nèi)蒙中部地區(qū)重要的生態(tài)屏障，有效地減緩著土地沙漠化的進(jìn)度，濕地生態(tài)系統(tǒng)通過(guò)強(qiáng)烈蒸發(fā)和蒸騰作用，把大量的水分送到大氣，調(diào)節(jié)降水，使局部氣溫和溫度等氣候條件得到改善。濕地釋放的CH4、H2S、N2O和CO2等微量氣體，對(duì)全球氣候變化都有重要意義。因此烏梁素海濕地具有重要的大氣調(diào)節(jié)功能，對(duì)改善周邊地區(qū)氣候、氣象條件和增加大氣降水、維護(hù)當(dāng)?shù)厣鷳B(tài)平衡起著相當(dāng)重要的作用。（3）基因保護(hù)的功能烏梁素海濕地又是“物種基因庫(kù)”。自然濕地不但是水生動(dòng)物、水生植物優(yōu)良的生存場(chǎng)所，也是多種珍稀瀕危野生動(dòng)物，特別是水禽必須的棲息、遷徙、越冬和繁殖地。烏梁素海是自治區(qū)級(jí)自然保護(hù)區(qū)。由于其得天獨(dú)厚的地理位置和自然條件，成為世界上十分著名的鳥類遷徙地和繁殖地。烏梁素海葦蒲叢生，水草豐盛，為鳥類的生存繁殖提供了良好的環(huán)境。這里共有鳥類180多種，屬國(guó)家一、二級(jí)保護(hù)的珍稀鳥類30 種，其中有黑鸛、白尾海雕、大鴇、白琵鷺和遺鷗5 種世界瀕危鳥類，是亞洲重要的濕地系統(tǒng)生物多樣性保護(hù)區(qū)。目前，烏梁素海濕地的疣鼻天鵝、白鷺等鳥類的繁殖地點(diǎn)明顯擴(kuò)大。疣鼻天鵝繁殖巢區(qū)由過(guò)去的10km范圍擴(kuò)大到30km。原來(lái)沒有的鳥種如草原雕、灰鶴、小天鵝、黃嘴白鷺等現(xiàn)在也來(lái)這里棲息，鳥類由原來(lái)的185種增加到現(xiàn)在的209種4。烏梁素海也是內(nèi)蒙古重要淡水漁業(yè)基地之一，有“北國(guó)水鄉(xiāng)”之稱。黃河鯉魚是烏梁素海的特產(chǎn)，色美味鮮，久負(fù)盛名。烏梁素海濕地還為許多物種保存了基因特性，使許多野生生物在不受干擾的情況下安然生存和繁衍。生態(tài)多樣性是生態(tài)系統(tǒng)健康的一個(gè)重要指標(biāo)。烏梁素海濕地基因保護(hù)對(duì)于生態(tài)系統(tǒng)的可持續(xù)性維持具有決定性的作用。烏梁素海是全球范圍內(nèi)荒漠半荒漠地區(qū)極為罕見的具有生物多樣性和環(huán)保多功能的大型草原湖泊，是地球上同一緯度最大的自然濕地，發(fā)揮著極其重要的濕地生態(tài)功能。同時(shí)，對(duì)維護(hù)世界性的生態(tài)平衡，保護(hù)物種的多樣性，履行全世界“拉姆薩爾公約”起著舉足輕重的作用。2.2防洪防凌功能定位寧蒙河道淤積日趨嚴(yán)重，導(dǎo)致主槽萎縮，河床抬高，河道過(guò)洪能力急劇減少，從而造成中小水水位明顯抬高，平灘流量大幅減小，特別是內(nèi)蒙古河道，如三湖河口斷面流量1000m3/s相應(yīng)水位1986年后持續(xù)抬升，至1996年升高約0.8m，到2004年又升高1.0m。2002年與1981年相比，巴彥高勒、三湖河口站2000m3/s相應(yīng)水位分別抬高1.7m。1990年以前，巴彥高勒三湖河口的平灘流量基本在30005000m3/s之間，1990年以后持續(xù)減小。根據(jù)2004年7月實(shí)測(cè)大斷面資料初步分析，巴彥高勒三湖河口河段平灘流量為1500m3/s左右，個(gè)別河段不足1000m3/s，三湖河口頭道拐河段的平灘流量約為2000m3/s，一些河段不足1500m3/s。寧蒙河段是黃河凌汛最為嚴(yán)重河段，寧蒙河段冬季封凍，凌汛期常造成較大災(zāi)害。近年來(lái)，由于寧蒙河道河槽淤積，使河槽變得寬淺散亂，輸水排冰能力下降，不時(shí)造成該河段堤防發(fā)生決口。如1993年12月7日晚，三盛公閘下3.3km處堤防決口，口門寬約40m，淹地耕地6萬(wàn)畝，13900多人搬遷，有9460家中進(jìn)水，12月12日堵復(fù)。2003年9月5日晚，在毛不浪孔兌入黃口對(duì)岸下部位，在大河流量?jī)H1300m3/s左右時(shí)發(fā)生決口，經(jīng)過(guò)各方面的努力，至9月9日堵復(fù)，也造成了大的經(jīng)濟(jì)損失。當(dāng)前，寧蒙河段，尤其是內(nèi)蒙古河段防洪防凌問(wèn)題突出，已直接威脅到兩岸群眾的安全。烏梁素海在寧蒙河段防洪防凌方面的地位相當(dāng)突出，是黃河汛期、凌期以及當(dāng)?shù)鼐值乇┯甑臏閹?kù)。對(duì)維持兩岸社會(huì)經(jīng)濟(jì)的發(fā)展，為確保人民群眾生命財(cái)產(chǎn)的安全，具有重要的作用。2.3水資源安全功能定位烏梁素海居于黃河干流中游的極為重要的位置，對(duì)于黃河中游的水資源安全發(fā)揮著極為重要的作用。烏梁素海作為河套灌區(qū)水利工程的重要組成部分，她接納了河套灌區(qū)90%以上的農(nóng)田排水，達(dá)5億多m3，也是工業(yè)、生活廢水的唯一承泄渠道。它對(duì)河套灌區(qū)節(jié)水灌溉工程的正常運(yùn)行和控制鹽堿化起著關(guān)鍵性的作用。廢水經(jīng)過(guò)烏梁素海湖泊的生物生化作用后，排入黃河，客觀上起到改變水質(zhì)、調(diào)控水量、控制河套地區(qū)鹽堿化的作用。減少了農(nóng)業(yè)排水對(duì)黃河水質(zhì)的直接影響程度。烏梁素?？梢哉f(shuō)是“八百里河套系于一身”，是黃河水質(zhì)的“晴雨表”。烏梁素海退水入黃河只有20km的河道，退水口到黃河包頭引用水取水口的距離較近，平水與枯水季節(jié)水量較少，其間黃河水體自凈能力較弱，因此，烏梁素海退水水質(zhì)將直接影響包頭取水口引用水安全，同時(shí)，烏梁素海較差的退水水質(zhì)對(duì)于小北干流，三門峽庫(kù)區(qū)，小浪底庫(kù)區(qū)等整個(gè)黃河下游的水資源安全將造成不可挽回的影響。目前來(lái)看，烏梁素海有24億m3的水量，是一個(gè)巨大的污染物存儲(chǔ)池，對(duì)于緩解黃河下游的污染具有重要的作用。同時(shí)烏梁素海是位于黃河寧蒙河段的一個(gè)天然水庫(kù)，維持著24億m3的水量，具有一定的調(diào)蓄能力。現(xiàn)有水域還是確保黃河內(nèi)蒙古河段枯水期不斷流的主要水源補(bǔ)給庫(kù)，對(duì)于維系黃河水系具有巨大的不可替代的作用。對(duì)于黃河中下游的水量調(diào)配發(fā)揮著積極的作用。2.4生態(tài)與環(huán)境保護(hù)功能定位河套灌區(qū)的主要生態(tài)問(wèn)題是土地退化，包括土地沙化、水土流失和土壤鹽堿化。烏梁素海對(duì)于河套地區(qū)的生態(tài)與環(huán)境保護(hù)顯得尤為重要。（1）延緩?fù)恋赝嘶蛷┠谞柺械赜蜻|闊，境內(nèi)有烏蘭布和沙漠500多萬(wàn)畝，烏拉特草原7000多萬(wàn)畝，河套平原有可耕地1000多萬(wàn)畝。烏蘭布和沙漠和烏拉特草原上退化的土地是巴彥淖爾市目前生態(tài)最為惡劣的地區(qū)，水土流失面積占總土地面積的83。巴彥淖爾市氣候條件屬中溫帶大陸性季風(fēng)氣候。冬長(zhǎng)夏短，光熱豐富，多年平均降雨量250mm左右，多年平均蒸發(fā)量2300mm。全年大風(fēng)日數(shù)達(dá)130d。其中八級(jí)以上大風(fēng)日數(shù)為60d，且經(jīng)常伴有沙塵暴。惡劣的氣候條件加上近幾年水資源短缺，灌區(qū)施行節(jié)水灌溉、渠道防滲等技術(shù)措施，減少了地下水的補(bǔ)給，加上個(gè)別地區(qū)過(guò)渡開發(fā)地下水資源，造成地下水位逐年下降，這些因素導(dǎo)致了原來(lái)半沙化的地區(qū)植被枯死逐漸沙化。無(wú)節(jié)制的墾荒，造成森林植被劇減，水土流失嚴(yán)重。在烏梁素海周圍恢復(fù)植被、攔截泥沙，進(jìn)行水土保持規(guī)劃，加強(qiáng)環(huán)境生態(tài)保護(hù)，對(duì)于降低土地沙化，減輕沙塵暴威脅和沙漠化發(fā)展具有重要意義。（2）降低土壤鹽堿化降雨稀少、蒸發(fā)強(qiáng)烈的氣候特征決定了烏梁素海地區(qū)土壤受到的天然淋洗作用十分微弱，土壤鹽堿化的威脅嚴(yán)重存在。同時(shí)灌區(qū)采用不合理的灌溉方式，造成灌溉用水過(guò)多，引起高礦化度的地下水位上升，加速了土壤蒸發(fā)積鹽。引黃灌區(qū)年灌溉用水量高達(dá)48億m3，加之排水不良，鹽堿化面積不斷擴(kuò)大。烏梁素海作為寧蒙灌區(qū)排水系統(tǒng)中最重要的一部分，烏梁素海的健康對(duì)于境地土壤鹽堿化起很重要的作用。2.5景觀生態(tài)功能定位大型淺水湖烏梁素海位于中國(guó)內(nèi)蒙古自治區(qū)，是中國(guó)西北部最大的內(nèi)陸湖泊，中國(guó)的第八大湖泊。在廣袤的半干旱草原地區(qū)，它是重要的濕地生態(tài)系統(tǒng)，具有重要的景觀生態(tài)功能。2001年，烏梁素海濕地開始實(shí)施生態(tài)保護(hù)示范工程，巴彥淖爾市委及上游各旗縣區(qū)切實(shí)加大了治污力度。隨著管護(hù)設(shè)施的投入使用，管護(hù)力度不斷加強(qiáng)，烏梁素海濕地的疣鼻天鵝、白鷺等鳥類的繁殖地點(diǎn)目前明顯擴(kuò)大。原來(lái)沒有的鳥種如草原雕、灰鶴、小天鵝、黃嘴白鷺等現(xiàn)在也來(lái)這里棲息，鳥類由原來(lái)的185種增加到現(xiàn)在的209種。濕地生物種群數(shù)量逐年明顯恢復(fù)和增加。在烏梁素?？梢杂^賞湖光山色，可以探索珍禽候鳥的活動(dòng)奧秘；也可以泛舟暢游，體察魚鄉(xiāng)的生活風(fēng)韻。烏梁素海的美麗的景觀生態(tài)吸引著大批游人，成為旅游觀光的勝地。 2.6生態(tài)服務(wù)功能定位生態(tài)系統(tǒng)服務(wù)功能是指生態(tài)系統(tǒng)與生態(tài)過(guò)程所形成及所維持的人類賴以生存的自然環(huán)境條件與效用。濕地作為地球上最富有生物多樣性、多功能的生態(tài)系統(tǒng)，為區(qū)域環(huán)境提供許多重要的服務(wù)功能。根據(jù)烏梁素海的特點(diǎn)，其產(chǎn)品生產(chǎn)功能包括提供生態(tài)系統(tǒng)產(chǎn)品和旅游休閑功能。生命支持系統(tǒng)功能包括水資源調(diào)節(jié)、水質(zhì)凈化、生物多樣性、大氣調(diào)節(jié)、文化科研等功能78。就產(chǎn)品生態(tài)功能而言，烏梁素海的主產(chǎn)業(yè)是漁業(yè)和蘆葦。烏梁素海是內(nèi)蒙古自治區(qū)第二大漁場(chǎng)，巴市最大的天然經(jīng)濟(jì)魚類生產(chǎn)區(qū)，聞名遐邇的黃河大鯉魚就盛產(chǎn)于此。歷史上，最高年份曾產(chǎn)鮮魚3000t，現(xiàn)年產(chǎn)經(jīng)濟(jì)魚類700多t，其中無(wú)公害水產(chǎn)品烏鱧(黑魚)年產(chǎn)125t，遠(yuǎn)銷山東、河北、河南等地。烏梁素海年產(chǎn)蘆葦11萬(wàn)t，是自治區(qū)最大的造紙?jiān)仙a(chǎn)基地，所產(chǎn)蘆葦具有纖維長(zhǎng)、出漿率高的特點(diǎn)，總供應(yīng)量占前旗兩家紙廠基礎(chǔ)原料的80%以上。年產(chǎn)薄葉6000 t，生產(chǎn)蔬菜大棚保溫簾600萬(wàn)m2，直接給呼、包郊區(qū)及巴市地區(qū)的蔬菜大棚提供了80%以上的保溫材料。烏梁素海是內(nèi)蒙古自治區(qū)西部久負(fù)盛名的旅游名勝景區(qū)，是旅游休閑的勝地。1998年，烏梁素海年接待達(dá)10萬(wàn)人(次)。烏梁素海是一個(gè)風(fēng)景秀麗的內(nèi)陸湖泊，不僅有豐富的植物資源，還擁有種類繁多的珍稀鳥類資源，還是內(nèi)蒙中部地區(qū)重要的水產(chǎn)品生產(chǎn)基地，烏梁素海水域面積寬廣，自然風(fēng)景極為優(yōu)美。烏梁素海因其獨(dú)特的自然環(huán)境發(fā)揮著重要的生態(tài)功能，具有極高文化科研價(jià)值。另外，可作為非常重要的生態(tài)教育示范基地，對(duì)大、中、小學(xué)生及普通公眾進(jìn)行環(huán)境教育。3結(jié)論（1）烏梁素海是中國(guó)八大淡水湖之一，也是全球荒漠半荒漠地區(qū)極為罕見的具有生物多樣性和環(huán)保多功能的大型草原湖泊，對(duì)維護(hù)世界性的生態(tài)平衡，保護(hù)物種的多樣性起著舉足輕重的作用。（2）烏梁素海當(dāng)前存在的生態(tài)與環(huán)境問(wèn)題不僅影響湖泊整體功能發(fā)揮，還直接影響到區(qū)域糧食安全，并威脅到黃河中下游供水安全與水資源安全。烏梁素海生態(tài)定位的提出明確了其生態(tài)系統(tǒng)的保護(hù)與修復(fù)的方向，具有極為重要的理論與實(shí)際意義，也是維持黃河健康生命的重要組成部分。（3）烏梁素海因其在黃河流域獨(dú)特的地理位置而具有重要的生態(tài)功能，即具有濕地生態(tài)功能、防洪防凌功能、水資源安全功能、景觀生態(tài)功能與生態(tài)服務(wù)功能等。參考文獻(xiàn)：1 孫惠民, 何江, 呂昌偉, 等. 烏梁素海氮污染及其空間分布格局. 地理研究, 2006, 25(6): 10031012.2 厚福祥, 鄧芳. 內(nèi)蒙古烏梁素海生態(tài)恢復(fù)工程試驗(yàn)研究. 內(nèi)蒙古大學(xué)學(xué)報(bào)(自然科學(xué)版), 2006, 37(1): 105110.3 Konarska. KM, Sutton P C, Castellon M. Evaluating scale dependence of ecosystem service valuation: a comparison of NOAA-AVHRR and Landsat TM datasets J. Ecological Economics, 2002, 41: 491507.4 邢蓮蓮. 烏梁素海鳥類志M . 呼和浩特:內(nèi)蒙古大學(xué)出版社, 1996, 150.5 Barbier E B. Valuing environmental function in developing countries J. Biodiversity Conservation, 1994, 1: 3450.6 Mitsch WJ, Gosselink J G. The value of wetlands: importance of scale and landscape setting J. Ecological Economics, 2000, 35(1): 2533.7 段曉男; 王效科; 歐陽(yáng)志云;烏梁素海濕地生態(tài)系統(tǒng)服務(wù)功能及價(jià)值評(píng)估. 資源科學(xué), 2005, 27(2): 110115.8 段曉男, 王效科, 歐陽(yáng)志云, 等. 烏梁素海野生蘆葦生物量及相關(guān)因子分析J. 植物生態(tài)學(xué)報(bào),2004 , 28 (2) : 246251. Preliminary analysis on orientation of the Wuliangsuhai lake ecosystemXin-feng FU1,2*The author: FU Xin-feng(1977-), male, Born in Zhoukou city, Henan province, Ph.D. Engineer. Major study fields are hydrology and water resource and ecology. Email: , Xiao-wei GU1, Xiao-yan LIU3, Hong-mou HE11 Yellow River Institute of Hydraulic Research, Zhengzhou 450003, China; 2 School of Geography, Beijing Normal University, Beijing 100875, China; 3 Hydrological Bureau of Yellow River Conservancy Commission; Zhengzhou 450004, China;Abstract: The Wuliangsuhai lake is a river trace one transformed from the Yellow River, which is one of Chinas eight major freshwater lakes, and which plays a decisive role in maintaining ecological balance of the basins wetlands and protecting diversity of species. Its deteriorating ecological environment has direct impact on regional food security and is a threat to water safety in the middle and lower Yellow River. According to the location of the Wuliangsuhai lake in the Yellow River Basin, the lake ecosystem is orientated clearly based on the perspective of ecological restoration. That is, the ecosystem is orientated in the following six aspects, such as the ecological function of wetlands, the flood control and ice jams prevention function, the water resources safety function, the ecological and environmental protection function, the landscape ecological function and the ecosystem service function. Thus, the orientated functions of ecosystem of Wuliangsuhai lake are preliminary analyzed.Key words: the Wuliangsuhai lake; wetland; orientation of ecosystem; ecological function1 IntroductionThe Wuliangsuhai lake is located in Wulateqianqi of Bayannor city in Inner Mongolia Autonomous Region, the west of which is the Hetao irrigation district and the east is the Urals Mountains, which is one of the largest lakes in Inner Mongolia 1,2. The lake is narrow in the south and wide in the north, which is longer from northeast to southwest, and which is about 35 km of the length and 412 km of the width3. Actually, the surface area of the Wuliangsuhai lake is 224.3 km2, with an average depth of 0.7 m, the surface elevation is 1018.6 m, and total water storage is about 0.20.4 billion m3.The Wuliangsuhai lake is a river trace one transformed from the Yellow River, which is one of Chinas eight major freshwater lakes as well as extremely rare prairie lake with many functions of biodiversity and environmental protection in global desert and semi-desert areas. The lake plays a decisive role in maintaining ecological balance of the basins wetlands and protecting diversity of species. The Wuliangsuhai lake not only contains a huge aquatic plants, fisheries, birds and tourism resources, but also bears an important ecological barrier in nations northern region. At the same time, the existing water area is main water supply reservoir ensuring constant flow at Inner Mongolia section of the Yellow River in dry season, which is also a flood retention reservoir in flood or ice flood period of the Yellow River as well as local storm stage. The lake has tremendous irreplaceable role in keeping the Yellow River water system. The lake is an important component of the Hetao irrigation district, which accepted more than 90% of farmland drainage water, and then drained into the Yellow River after biological and biochemical reaction that plays a key role of water quality changing and water regulating and salinization controlling of the Hetao irrigation district objectively. And that lowered directly influence of agricultural drainage water on the Yellow River. The Wuliangsuhai lake is also an important migrating and heredity and self-multiply place for migratory birds in northern China, which has more than 180 kinds of birds that the rare birds of the first or secondary national protected species are more than 30 kinds, which plays an irreplaceable role of protecting species diversity. Some materials showed that the Wuliangsuhai lake is extremely rare large-lake with high ecological benefits in semi-desert region in the world 4.In recent years, industrialization and urbanization is speeding up in the region, which caused industrial wastewater, municipal sewage and agricultural drainage water. Considering impact of the lake its own, therefore, the lake is in serious eutrophication, and eco-environment of the water is deteriorated 1. The outstanding Performance of that is in the flowing: First, total phosphorus and total nitrogen is in serious superscale, and the nutrients is excessive in water, and eutrophication problem is serious; Second, aquatic plants is in excessive growth, marshes trend is increasing; Third, soil erosion is serious around the lake, which accelerated shrinkage of the lake; Fourth, the water source is reducing, the water level drops rapidly. All of these not only affect overall function of the lake, but also have a direct impact on regional food security, and threatened water supply safety in the middle and lower reaches of Yellow River. The water eco-environment issue of the Wuliangsuhai lake has become constraints of sustainable economic and social development in the region and even the whole Inner Mongolia Autonomous Region. Therefore, from the perspective of ecological restoration the six aspects of ecological orientation of the Wuliangsuhai lake are clear, which is pointing out the direction for the lakes ecological protection and restoration, and which is in very important practical significance. The orientation of the Wuliangsuhai lake ecosystem plays an important ecological function as part of theory and practice of Maintaining the healthy life of the Yellow River.2 Orientation of the Wuliangsuhai lake ecosystem2.1 Orientation of wetland ecological functions (1)Function of decontaminationThe Wuliangsuhai lake wetland is the bank and cleaner of water resources. Moreover, wetland has a strong function of water regulation and hydrological cycle, which can store, strand precipitation and surface runoff effectively, and add groundwater. The wetland also has strong function of pollution degradation and water purification. The wetland soil and in which survives a variety of plant communities, microbial communities have the function of adsorption, absorption and decomposition of pollutants, and of cleaning up the environment, which play an important role in removing suspended solids, promoting nutrients recycling and generating O2. Thus, the Wuliangsuhai lake wetland is called the natural kidney of Bayannor. The lake wetland has reed and many other aquatic plants in which concentration of heavy metals is much higher than that of the surrounding water. The reed in wetland has the role of absorption, metabolism, accumulation of contaminated material, and sewage purification. The total water surface and reed-covered area of the Wuliangsuhai lake is 346 km2, and water volume is 0.20.4 billion m3 with more powerful decontamination capabilities 5,6.(2) Function of climate regulationThe Wuliangsuhai lake wetland is also an important carbon storage and carbon sink. Remote sensing imagery in 2001 interpreted that the water surface area of 167.6 km2, the area of natural reed covers 146 km2, coupled with the reed growing in abandoned farmland, its total area is 346 km2. the Wuliangsuhai lake is an important ecological barrier in the central region of Inner Mongolia, which is slowing progress of the land desertification effectively. The wetland ecosystem sends a great deal of water to atmosphere to regulate precipitation and to improve local air temperature and other climate conditions through strong evaporation and transpiration. The CH4, H2S, CO2 and N2O, and other trace gases released from the wetland are of great significance on the global climate change. Therefore, the Wuliangsuhai lake wetland has important regulatory function of the atmosphere, plays a very important role in improving the climate and weather condition in surrounding areas, and increasing atmospheric precipitation, and preserving local ecological balance.(3) Function of gene protectionThe Wuliangsuhai lake wetland is also a species gene pool. Natural wetland is not only an excellent place for aquatic animals and aquatic plants to survive, but also a habitating, Migration, overyearing and propagation place for a variety of rare and endangered wild animals especially waterfowl. The lake is a nature reserve of autonomous region-level. Because of its unique geographical location and natural conditions, the lake becomes one of the worlds well-known bird migration and propagation place. The numerous reed and aquatic plants in the lake provides a good environment for the birds survival and propagation. The lake has more than 180 kinds of birds that the rare birds of the first or secondary national protected species are more than 30 kinds, which including five kind of world endangered birds such as black storks, white-tailed sea eagles, bustards, white spoonbills and YI gulls, which is an important wetland biodiversity conservation zones in Asia. At present, the nose warts swans, egrets and other birds propagation sites are expanding significantly in the Wuliangsuhai lake wetland. The propagation nest area of the nose warts swan expands from 10 km to 30 km. Here habitat new birds such as grassland eagles, gray cranes, little swans and egretta eulophotes. The birds increase from 185 kinds to the current figure of 2094. The Wuliangsuhai lake is also an important base of freshwater fisheries in Inner Mongolia, which is called North Water. The Yellow River carp is specialty with delicious fresh color and long repute in the Wuliangsuhai lake. The wetland preserves genetic characteristics for many species, makes much wildlife survive and thrive without interference.Ecological diversity is an important indicator of ecosystem health. The wetland gene protection of the Wuliangsuhai lake plays a decisive role of maintaining the sustainability of the wetland ecosystem. The lake is an extremely rare prairie lake with many functions of biodiversity and environmental protection in global desert and semi-desert areas, and is the largest natural wetland at the same latitude of the Earth, has an extremely important ecological function of the wetland. At the same while, the lake plays the pivotal role of maintaining of the ecological balance of world, and of protecting diversity of species, and of carrying out the whole world Ramsar Convention.2.2 Function of flood control and ice jams preventionThe riverway of Ningxia-Inner Mongolia section is silting seriously, which results in main channels shrinking, riverbeds elevating, and the rivers flood conveying capacity is drastically reduced. And that small and medium-sized water level was elevated significantly and bankfull discharge is reduced substantially. Take the Inner Mongolia riverway for example, when the Sanhuhekou section discharge is 1000m3/s, corresponding water level is sustained uplifting after 1986, and increases abo