芒果视频

云霧山自然(ran)保(bao)護區(qu)（Yunwushan Nature Re-Serve） 中(zhong)國第2個草(cao)(cao)(cao)原(yuan)(yuan)保(bao)護區(qu)。屬黃(huang)土(tu)(tu)高原(yuan)(yuan)長芒草(cao)(cao)(cao)群(qun)系(xi)保(bao)留較好的(de)(de)(de)典(dian)型(xing)地(di)區(qu)，對開展草(cao)(cao)(cao)原(yuan)(yuan)生(sheng)態系(xi)統的(de)(de)(de)定(ding)位(wei)研究(jiu)，探索草(cao)(cao)(cao)原(yuan)(yuan)、畜牧、水土(tu)(tu)保(bao)持(chi)間(jian)的(de)(de)(de)關系(xi)有(you)重(zhong)要(yao)(yao)科研價值。位(wei)于寧(ning)夏固原(yuan)(yuan)縣東北，為中(zhong)溫(wen)(wen)帶半干(gan)旱黃(huang)土(tu)(tu)丘陵(ling)低山區(qu)。已劃定(ding)自然(ran)保(bao)護區(qu)面積1300公頃。海拔(ba)多在1800～1900米，頂(ding)峰2148米。年均溫(wen)(wen)6℃，年降水量約350～400毫米，土(tu)(tu)壤(rang)主(zhu)要(yao)(yao)為淡(dan)黑壚土(tu)(tu)。有(you)種(zhong)子植(zhi)物181種(zhong)，其(qi)中(zhong)草(cao)(cao)(cao)本植(zhi)物140多種(zhong)，包括飼用(yong)植(zhi)物110種(zhong)，藥用(yong)植(zhi)物41種(zhong)；脊(ji)椎動(dong)物80種(zhong)。共有(you)典(dian)型(xing)草(cao)(cao)(cao)原(yuan)(yuan)、草(cao)(cao)(cao)甸(dian)草(cao)(cao)(cao)原(yuan)(yuan)、荒漠草(cao)(cao)(cao)原(yuan)(yuan)、中(zhong)生(sheng)落葉闊葉灌(guan)叢(cong)和(he)耐旱落葉灌(guan)叢(cong)等5個植(zhi)被亞型(xing)，11個重(zhong)要(yao)(yao)群(qun)系(xi)。其(qi)中(zhong)以(yi)典(dian)型(xing)草(cao)(cao)(cao)原(yuan)(yuan)的(de)(de)(de)長芒草(cao)(cao)(cao)群(qun)系(xi)占優勢，為黃(huang)土(tu)(tu)高原(yuan)(yuan)叢(cong)生(sheng)禾草(cao)(cao)(cao)草(cao)(cao)(cao)原(yuan)(yuan)的(de)(de)(de)代表(biao)類型(xing)。其(qi)次為百里香、鐵桿蒿、茭蒿、委陵(ling)菜等。經幾年來(lai)的(de)(de)(de)保(bao)護，草(cao)(cao)(cao)場生(sheng)產力已由畝(mu)產鮮草(cao)(cao)(cao)100～150千克提高到400～600千克，是(shi)良好的(de)(de)(de)常年牧場。

歷史

1982年，固(gu)原縣在云霧(wu)山建立了面積達4000公頃的草原自(zi)然(ran)保護區(qu)，1995年被(bei)列(lie)為省(區(qu))級自(zi)然(ran)保護區(qu)，這也是我國(guo)黃土(tu)高原建立的第一個草地類自(zi)然(ran)保護區(qu)。

地理環境

云霧山主

云霧山草(cao)(cao)原自然保(bao)護區(qu)峰海拔(ba)2128米(mi)，山基由白云巖、紅色砂礫組成，土壤為地灰褐土和淡黑壚土，生長草(cao)(cao)甸植(zhi)被。

自然資源

保(bao)護(hu)(hu)區內有植(zhi)(zhi)物51科131屬182種(zhong)，動物40科74屬80種(zhong)，益蟲(chong)14科28種(zhong)，蜘(zhi)蛛5科7種(zhong)。保(bao)護(hu)(hu)區所保(bao)護(hu)(hu)的對象就是這些草原(yuan)植(zhi)(zhi)被及其生(sheng)(sheng)態系(xi)統(tong)，包(bao)括氣候(hou)、土(tu)壤、昆蟲(chong)、野(ye)生(sheng)(sheng)動植(zhi)(zhi)物、微(wei)生(sheng)(sheng)物等。

生態保護

自80年云(yun)霧(wu)山(shan)草(cao)(cao)原(yuan)自然保護區自然風光代(dai)中期于日本(ben)、美國(guo)(guo)(guo)、德國(guo)(guo)(guo)等(deng)生(sheng)態(tai)(tai)(tai)學(xue)(xue)、土(tu)(tu)壤學(xue)(xue)和生(sheng)物多樣性等(deng)方面的科(ke)(ke)學(xue)(xue)家開展(zhan)了(le)合作研究(jiu)(jiu)，目前已成為(wei)中國(guo)(guo)(guo)科(ke)(ke)學(xue)(xue)院(yuan)水利部水土(tu)(tu)保持研究(jiu)(jiu)所、西北(bei)農(nong)(nong)林(lin)科(ke)(ke)技大(da)學(xue)(xue)、蘭(lan)州大(da)學(xue)(xue)、寧夏大(da)學(xue)(xue)草(cao)(cao)業(ye)(ye)(ye)科(ke)(ke)學(xue)(xue)研究(jiu)(jiu)與(yu)(yu)(yu)研究(jiu)(jiu)生(sheng)培養(yang)、農(nong)(nong)業(ye)(ye)(ye)部狐貍(li)野性化(hua)馴養(yang)和國(guo)(guo)(guo)家林(lin)業(ye)(ye)(ye)局退化(hua)生(sheng)態(tai)(tai)(tai)系(xi)統(tong)定(ding)位(wei)監測基地及全球氣(qi)候變化(hua)定(ding)位(wei)監測點，經過近30年的封禁(jin)和草(cao)(cao)原(yuan)生(sheng)態(tai)(tai)(tai)系(xi)統(tong)定(ding)位(wei)監測研究(jiu)(jiu)，生(sheng)態(tai)(tai)(tai)經濟社會效益顯著，已成為(wei)我(wo)國(guo)(guo)(guo)西部草(cao)(cao)原(yuan)植被恢復(fu)與(yu)(yu)(yu)草(cao)(cao)原(yuan)自然修復(fu)的一個成功(gong)典范(fan)，為(wei)國(guo)(guo)(guo)家退耕還林(lin)草(cao)(cao)與(yu)(yu)(yu)地方封山(shan)禁(jin)牧工程的實施提供了(le)重要科(ke)(ke)學(xue)(xue)依據。

天然草地自然修復成效顯著

20世紀80年(nian)(nian)代(dai)初期(qi)(qi)，在(zai)區域考察的(de)(de)(de)(de)基礎上，我們提出(chu)并在(zai)我國西部(bu)寧夏固原(yuan)(yuan)(yuan)(yuan)云霧山建(jian)立了(le)最早的(de)(de)(de)(de)典型草(cao)(cao)(cao)(cao)(cao)原(yuan)(yuan)(yuan)(yuan)自然保(bao)護(hu)(hu)區，封(feng)禁(jin)保(bao)護(hu)(hu)面(mian)積由(you)0.23萬(wan)hm已擴大(da)到(dao)1 萬(wan)hm。通過(guo)近(jin)30年(nian)(nian)封(feng)禁(jin)定位試驗，根據草(cao)(cao)(cao)(cao)(cao)地(di)(di)(di)(di)退(tui)化(hua)(hua)程度(du)(du)采取封(feng)禁(jin)、改(gai)良、補播等(deng)草(cao)(cao)(cao)(cao)(cao)地(di)(di)(di)(di)建(jian)設(she)技(ji)術(shu)途徑，使退(tui)化(hua)(hua)草(cao)(cao)(cao)(cao)(cao)地(di)(di)(di)(di)植(zhi)(zhi)(zhi)被種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)類(lei)成分(fen)(fen)(fen)(fen)、牧草(cao)(cao)(cao)(cao)(cao)生(sheng)長(chang)發(fa)(fa)育和(he)(he)(he)草(cao)(cao)(cao)(cao)(cao)地(di)(di)(di)(di)生(sheng)境條件得到(dao)了(le)全面(mian)改(gai)善，草(cao)(cao)(cao)(cao)(cao)地(di)(di)(di)(di)生(sheng)產力有了(le)很大(da)提高，草(cao)(cao)(cao)(cao)(cao)群種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)類(lei)成分(fen)(fen)(fen)(fen)發(fa)(fa)生(sheng)了(le)顯著(zhu)變化(hua)(hua)。封(feng)禁(jin)初期(qi)(qi)，草(cao)(cao)(cao)(cao)(cao)原(yuan)(yuan)(yuan)(yuan)植(zhi)(zhi)(zhi)物(wu)(wu)(wu)(wu)僅為(wei)(wei)(wei)(wei)53種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)，其(qi)(qi)中(zhong)(zhong)(zhong)灌木和(he)(he)(he)半灌木占8%，草(cao)(cao)(cao)(cao)(cao)本占92%，多(duo)數以旱(han)(han)生(sheng)植(zhi)(zhi)(zhi)物(wu)(wu)(wu)(wu)組成，物(wu)(wu)(wu)(wu)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)密(mi)度(du)(du)平(ping)均(jun)為(wei)(wei)(wei)(wei)5種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)/m。隨(sui)封(feng)禁(jin)期(qi)(qi)延長(chang)物(wu)(wu)(wu)(wu)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)密(mi)度(du)(du)逐漸增(zeng)加，封(feng)禁(jin)的(de)(de)(de)(de)第15年(nian)(nian)(1996年(nian)(nian))，物(wu)(wu)(wu)(wu)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)密(mi)度(du)(du)達(da)到(dao)了(le)峰(feng)值，平(ping)均(jun)為(wei)(wei)(wei)(wei)33種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)/m，是(shi)(shi)未(wei)(wei)封(feng)禁(jin)的(de)(de)(de)(de)3.1倍，草(cao)(cao)(cao)(cao)(cao)地(di)(di)(di)(di)群落物(wu)(wu)(wu)(wu)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)數達(da)到(dao)186種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)，是(shi)(shi)未(wei)(wei)封(feng)禁(jin)的(de)(de)(de)(de)3.5倍，其(qi)(qi)中(zhong)(zhong)(zhong)灌木和(he)(he)(he)半灌木占12%，草(cao)(cao)(cao)(cao)(cao)本占88%，多(duo)數以中(zhong)(zhong)(zhong)生(sheng)和(he)(he)(he)中(zhong)(zhong)(zhong)旱(han)(han)生(sheng)植(zhi)(zhi)(zhi)物(wu)(wu)(wu)(wu)組成，并出(chu)現大(da)量(liang)森林草(cao)(cao)(cao)(cao)(cao)原(yuan)(yuan)(yuan)(yuan)地(di)(di)(di)(di)帶的(de)(de)(de)(de)灌木和(he)(he)(he)草(cao)(cao)(cao)(cao)(cao)本植(zhi)(zhi)(zhi)物(wu)(wu)(wu)(wu)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)。草(cao)(cao)(cao)(cao)(cao)地(di)(di)(di)(di)覆蓋度(du)(du)由(you)35%提高到(dao)95%，生(sheng)物(wu)(wu)(wu)(wu)量(liang)由(you)750提高到(dao)7560kg/hm。特別是(shi)(shi)在(zai)1986和(he)(he)(he)1991年(nian)(nian)降(jiang)雨量(liang)274.8mm和(he)(he)(he)259.7mm的(de)(de)(de)(de)大(da)旱(han)(han)年(nian)(nian)份，寧夏固原(yuan)(yuan)(yuan)(yuan)2/3的(de)(de)(de)(de)地(di)(di)(di)(di)方由(you)于干(gan)旱(han)(han)缺草(cao)(cao)(cao)(cao)(cao)造成60%~70%牲畜死亡，但封(feng)禁(jin)保(bao)護(hu)(hu)和(he)(he)(he)改(gai)良草(cao)(cao)(cao)(cao)(cao)地(di)(di)(di)(di)周圍的(de)(de)(de)(de)鄉村5.0~6.0萬(wan)頭牲畜得到(dao)了(le)挽救，直(zhi)接減(jian)少(shao)經濟損失500萬(wan)元，充分(fen)(fen)(fen)(fen)發(fa)(fa)揮了(le)"自然保(bao)護(hu)(hu)區"和(he)(he)(he)改(gai)良草(cao)(cao)(cao)(cao)(cao)地(di)(di)(di)(di)的(de)(de)(de)(de)顯著(zhu)作(zuo)用，保(bao)護(hu)(hu)區生(sheng)態、經濟、社(she)會效益顯著(zhu)，受到(dao)了(le)各(ge)級政(zheng)府及群眾的(de)(de)(de)(de)一致贊揚，得到(dao)了(le)地(di)(di)(di)(di)方政(zheng)府表彰和(he)(he)(he)獎勵。但封(feng)禁(jin)15年(nian)(nian)后(hou)隨(sui)封(feng)禁(jin)時(shi)間的(de)(de)(de)(de)延長(chang)，物(wu)(wu)(wu)(wu)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)密(mi)度(du)(du)趨于下降(jiang)，第24-28年(nian)(nian)(2008年(nian)(nian))物(wu)(wu)(wu)(wu)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)密(mi)度(du)(du)僅為(wei)(wei)(wei)(wei)19.1種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)/m。封(feng)禁(jin)期(qi)(qi)過(guo)長(chang)因(yin)枯草(cao)(cao)(cao)(cao)(cao)層加厚而影(ying)響(xiang)草(cao)(cao)(cao)(cao)(cao)地(di)(di)(di)(di)自然更新(xin)與物(wu)(wu)(wu)(wu)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)多(duo)樣性(xing)(xing)增(zeng)加。草(cao)(cao)(cao)(cao)(cao)地(di)(di)(di)(di)土(tu)壤種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)子(zi)(zi)(zi)庫(ku)研究表明，云霧山草(cao)(cao)(cao)(cao)(cao)地(di)(di)(di)(di)土(tu)壤種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)子(zi)(zi)(zi)庫(ku)在(zai)空間分(fen)(fen)(fen)(fen)布上呈現一定的(de)(de)(de)(de)規律(lv)性(xing)(xing)，種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)子(zi)(zi)(zi)密(mi)度(du)(du)在(zai)垂(chui)直(zhi)分(fen)(fen)(fen)(fen)布上呈現出(chu)由(you)表層土(tu)壤向(xiang)深層逐層減(jian)少(shao)的(de)(de)(de)(de)變化(hua)(hua)規律(lv)，水(shui)平(ping)分(fen)(fen)(fen)(fen)布上變化(hua)(hua)規律(lv)為(wei)(wei)(wei)(wei):封(feng)禁(jin)>放牧;陰坡>陽坡;下坡>中(zhong)(zhong)(zhong)坡>上坡，這些均(jun)是(shi)(shi)影(ying)響(xiang)群落物(wu)(wu)(wu)(wu)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)多(duo)樣性(xing)(xing)增(zeng)加和(he)(he)(he)草(cao)(cao)(cao)(cao)(cao)地(di)(di)(di)(di)繁殖更新(xin)的(de)(de)(de)(de)關鍵問題。

通過近(jin)30年(nian)(nian)的(de)(de)自然(ran)封禁(jin)(jin)試驗(yan)，明確提(ti)出草(cao)(cao)地(di)(di)(di)(di)恢(hui)復(fu)的(de)(de)適(shi)宜封禁(jin)(jin)期:在(zai)(zai)半干(gan)旱(han)區(qu)森林(lin)草(cao)(cao)原(yuan)(yuan)地(di)(di)(di)(di)帶，草(cao)(cao)甸(dian)植(zhi)(zhi)被(bei)的(de)(de)適(shi)宜恢(hui)復(fu)期為3~5年(nian)(nian)，方(fang)可(ke)進行(xing)合(he)理的(de)(de)放牧或(huo)刈割利(li)用(yong)(yong)，對利(li)用(yong)(yong)過度退化(hua)(hua)嚴(yan)重的(de)(de)草(cao)(cao)甸(dian)植(zhi)(zhi)被(bei)在(zai)(zai)平水(shui)年(nian)(nian)需要封禁(jin)(jin)8~12年(nian)(nian);在(zai)(zai)典型草(cao)(cao)原(yuan)(yuan)地(di)(di)(di)(di)帶，草(cao)(cao)地(di)(di)(di)(di)植(zhi)(zhi)被(bei)適(shi)宜恢(hui)復(fu)期為5~8年(nian)(nian)，方(fang)可(ke)進行(xing)合(he)理刈割和(he)放牧利(li)用(yong)(yong)，退化(hua)(hua)嚴(yan)重的(de)(de)草(cao)(cao)地(di)(di)(di)(di)植(zhi)(zhi)被(bei)在(zai)(zai)平水(shui)年(nian)(nian)約(yue)需封禁(jin)(jin)10~15年(nian)(nian);在(zai)(zai)荒漠草(cao)(cao)原(yuan)(yuan)地(di)(di)(di)(di)帶，草(cao)(cao)地(di)(di)(di)(di)植(zhi)(zhi)被(bei)適(shi)宜恢(hui)復(fu)期為10~12年(nian)(nian)，方(fang)可(ke)進行(xing)合(he)理的(de)(de)刈割和(he)放牧利(li)用(yong)(yong)，退化(hua)(hua)嚴(yan)重草(cao)(cao)地(di)(di)(di)(di)在(zai)(zai)平水(shui)年(nian)(nian)約(yue)需封禁(jin)(jin)15~20年(nian)(nian)。這一結論通過多年(nian)(nian)的(de)(de)試驗(yan)驗(yan)證(zheng)，已建(jian)立了示范樣(yang)板，為同類型區(qu)天然(ran)植(zhi)(zhi)被(bei)恢(hui)復(fu)利(li)用(yong)(yong)提(ti)供了重要科學依據。

封禁草地自然演替過程與規律

通過近(jin)30年(nian)的(de)(de)(de)(de)(de)(de)(de)(de)(de)封(feng)(feng)禁(jin)試(shi)驗，首次劃分了草(cao)地植(zhi)被恢復(fu)(fu)與(yu)時(shi)序演(yan)(yan)替(ti)過程，分為(wei)(wei)(wei)五(wu)個(ge)階(jie)(jie)段(duan)(duan):第一(yi)階(jie)(jie)段(duan)(duan)為(wei)(wei)(wei)種(zhong)(zhong)(zhong)群(qun)(qun)(qun)持(chi)(chi)續(xu)增長聚集階(jie)(jie)段(duan)(duan)，即在(zai)(zai)封(feng)(feng)禁(jin)的(de)(de)(de)(de)(de)(de)(de)(de)(de)1~3年(nian)內(nei)以本氏(shi)(shi)(shi)針(zhen)(zhen)茅(mao)(mao)鄉土種(zhong)(zhong)(zhong)為(wei)(wei)(wei)主的(de)(de)(de)(de)(de)(de)(de)(de)(de)建(jian)群(qun)(qun)(qun)種(zhong)(zhong)(zhong)與(yu)其它優(you)勢(shi)種(zhong)(zhong)(zhong)、伴生(sheng)種(zhong)(zhong)(zhong)和偶見(jian)種(zhong)(zhong)(zhong)不斷(duan)適應新的(de)(de)(de)(de)(de)(de)(de)(de)(de)生(sheng)境，各項生(sheng)長指標穩(wen)定(ding)增長;第二階(jie)(jie)段(duan)(duan)為(wei)(wei)(wei)種(zhong)(zhong)(zhong)間激烈(lie)競(jing)爭(zheng)(zheng)階(jie)(jie)段(duan)(duan)，也是封(feng)(feng)禁(jin)的(de)(de)(de)(de)(de)(de)(de)(de)(de)第4~9年(nian)，植(zhi)物(wu)(wu)(wu)(wu)數(shu)量(liang)大幅度(du)增長，并(bing)適應了新的(de)(de)(de)(de)(de)(de)(de)(de)(de)生(sheng)境，且(qie)相(xiang)互展開了激烈(lie)的(de)(de)(de)(de)(de)(de)(de)(de)(de)種(zhong)(zhong)(zhong)間競(jing)爭(zheng)(zheng)與(yu)自(zi)然選擇(ze);第三階(jie)(jie)段(duan)(duan)為(wei)(wei)(wei)建(jian)群(qun)(qun)(qun)種(zhong)(zhong)(zhong)加速恢復(fu)(fu)演(yan)(yan)替(ti)階(jie)(jie)段(duan)(duan)，即封(feng)(feng)禁(jin)的(de)(de)(de)(de)(de)(de)(de)(de)(de)10~15年(nian)，植(zhi)物(wu)(wu)(wu)(wu)在(zai)(zai)激烈(lie)的(de)(de)(de)(de)(de)(de)(de)(de)(de)種(zhong)(zhong)(zhong)間競(jing)爭(zheng)(zheng)中(zhong)(zhong)"物(wu)(wu)(wu)(wu)競(jing)天擇(ze)、適者生(sheng)存"，本氏(shi)(shi)(shi)針(zhen)(zhen)茅(mao)(mao)形成明(ming)顯(xian)建(jian)群(qun)(qun)(qun)種(zhong)(zhong)(zhong)，并(bing)不斷(duan)加速種(zhong)(zhong)(zhong)群(qun)(qun)(qun)自(zi)身的(de)(de)(de)(de)(de)(de)(de)(de)(de)恢復(fu)(fu)與(yu)擴展, 且(qie)已達到"亞頂極";第四階(jie)(jie)段(duan)(duan)為(wei)(wei)(wei)建(jian)群(qun)(qun)(qun)種(zhong)(zhong)(zhong)的(de)(de)(de)(de)(de)(de)(de)(de)(de)定(ding)居(ju)生(sheng)長階(jie)(jie)段(duan)(duan)，封(feng)(feng)禁(jin)的(de)(de)(de)(de)(de)(de)(de)(de)(de)16~21年(nian)本氏(shi)(shi)(shi)針(zhen)(zhen)茅(mao)(mao)種(zhong)(zhong)(zhong)群(qun)(qun)(qun)個(ge)體數(shu)量(liang)的(de)(de)(de)(de)(de)(de)(de)(de)(de)變(bian)化(hua)基(ji)本穩(wen)定(ding)在(zai)(zai)19株/m，占群(qun)(qun)(qun)落總數(shu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)90.5%，已達到"亞頂極";第五(wu)階(jie)(jie)段(duan)(duan)22~28年(nian)本氏(shi)(shi)(shi)針(zhen)(zhen)茅(mao)(mao)種(zhong)(zhong)(zhong)群(qun)(qun)(qun)的(de)(de)(de)(de)(de)(de)(de)(de)(de)生(sheng)長繁殖(zhi)受枯(ku)草(cao)層的(de)(de)(de)(de)(de)(de)(de)(de)(de)影響，個(ge)體數(shu)量(liang)急劇下降，優(you)勢(shi)種(zhong)(zhong)(zhong)大針(zhen)(zhen)茅(mao)(mao)種(zhong)(zhong)(zhong)群(qun)(qun)(qun)的(de)(de)(de)(de)(de)(de)(de)(de)(de)數(shu)量(liang)巨增，密度(du)為(wei)(wei)(wei)16~26株/m，有替(ti)代本氏(shi)(shi)(shi)針(zhen)(zhen)茅(mao)(mao)的(de)(de)(de)(de)(de)(de)(de)(de)(de)趨勢(shi)。同時(shi)在(zai)(zai)草(cao)原(yuan)(yuan)群(qun)(qun)(qun)落生(sheng)長的(de)(de)(de)(de)(de)(de)(de)(de)(de)溝(gou)道(dao)還出現(xian)大量(liang)的(de)(de)(de)(de)(de)(de)(de)(de)(de)中(zhong)(zhong)生(sheng)灌(guan)木，多為(wei)(wei)(wei)森(sen)林(lin)草(cao)原(yuan)(yuan)區成分，已由草(cao)原(yuan)(yuan)群(qun)(qun)(qun)落坡(po)下部的(de)(de)(de)(de)(de)(de)(de)(de)(de)陰(yin)坡(po)或半陰(yin)坡(po)以片狀(zhuang)分布，逐漸向草(cao)原(yuan)(yuan)腹地呈(cheng)零星狀(zhuang)入侵，使草(cao)原(yuan)(yuan)群(qun)(qun)(qun)落的(de)(de)(de)(de)(de)(de)(de)(de)(de)演(yan)(yan)替(ti)進入了一(yi)個(ge)重要的(de)(de)(de)(de)(de)(de)(de)(de)(de)階(jie)(jie)段(duan)(duan)，形成了一(yi)個(ge)明(ming)顯(xian)的(de)(de)(de)(de)(de)(de)(de)(de)(de)拐點，直到封(feng)(feng)禁(jin)的(de)(de)(de)(de)(de)(de)(de)(de)(de)第28年(nian)物(wu)(wu)(wu)(wu)種(zhong)(zhong)(zhong)豐(feng)富度(du)仍保持(chi)(chi)在(zai)(zai)148種(zhong)(zhong)(zhong)，具(ju)有典型草(cao)原(yuan)(yuan)群(qun)(qun)(qun)落向森(sen)林(lin)草(cao)原(yuan)(yuan)群(qun)(qun)(qun)落類型演(yan)(yan)替(ti)發展的(de)(de)(de)(de)(de)(de)(de)(de)(de)趨勢(shi)。

封禁草地適度刈割利用技術

在黃土(tu)高原(yuan)典型草(cao)原(yuan)地(di)帶，通(tong)過不同刈割(ge)(ge)強度試驗，表明適度刈割(ge)(ge)可使草(cao)地(di)保持較高的物種多樣(yang)性和生(sheng)產力，并能促進(jin)草(cao)地(di)物質(zhi)平衡及(ji)良(liang)性循環，為封(feng)禁草(cao)地(di)的合理刈割(ge)(ge)利用提供了重要依(yi)據。