芒果视频下载

云霧山(shan)自然保(bao)(bao)護(hu)(hu)區(qu)（Yunwushan Nature Re-Serve） 中(zhong)國第2個(ge)(ge)草(cao)(cao)(cao)(cao)(cao)(cao)原(yuan)保(bao)(bao)護(hu)(hu)區(qu)。屬黃(huang)土(tu)高(gao)原(yuan)長(chang)芒草(cao)(cao)(cao)(cao)(cao)(cao)群(qun)系(xi)(xi)保(bao)(bao)留較好的(de)(de)典型(xing)地區(qu)，對開展草(cao)(cao)(cao)(cao)(cao)(cao)原(yuan)生(sheng)態系(xi)(xi)統的(de)(de)定位研究，探(tan)索(suo)草(cao)(cao)(cao)(cao)(cao)(cao)原(yuan)、畜牧、水(shui)土(tu)保(bao)(bao)持間的(de)(de)關(guan)系(xi)(xi)有重要(yao)科研價值。位于寧(ning)夏(xia)固原(yuan)縣東北，為中(zhong)溫帶半干旱(han)(han)黃(huang)土(tu)丘陵低山(shan)區(qu)。已劃定自然保(bao)(bao)護(hu)(hu)區(qu)面積(ji)1300公頃。海(hai)拔多在1800～1900米(mi)，頂峰2148米(mi)。年(nian)均溫6℃，年(nian)降水(shui)量約350～400毫米(mi)，土(tu)壤主要(yao)為淡黑壚土(tu)。有種(zhong)子植(zhi)物181種(zhong)，其(qi)中(zhong)草(cao)(cao)(cao)(cao)(cao)(cao)本植(zhi)物140多種(zhong)，包括飼用植(zhi)物110種(zhong)，藥用植(zhi)物41種(zhong)；脊椎動物80種(zhong)。共有典型(xing)草(cao)(cao)(cao)(cao)(cao)(cao)原(yuan)、草(cao)(cao)(cao)(cao)(cao)(cao)甸(dian)草(cao)(cao)(cao)(cao)(cao)(cao)原(yuan)、荒漠草(cao)(cao)(cao)(cao)(cao)(cao)原(yuan)、中(zhong)生(sheng)落葉(xie)闊(kuo)葉(xie)灌叢(cong)和耐旱(han)(han)落葉(xie)灌叢(cong)等5個(ge)(ge)植(zhi)被亞型(xing)，11個(ge)(ge)重要(yao)群(qun)系(xi)(xi)。其(qi)中(zhong)以(yi)典型(xing)草(cao)(cao)(cao)(cao)(cao)(cao)原(yuan)的(de)(de)長(chang)芒草(cao)(cao)(cao)(cao)(cao)(cao)群(qun)系(xi)(xi)占優勢(shi)，為黃(huang)土(tu)高(gao)原(yuan)叢(cong)生(sheng)禾草(cao)(cao)(cao)(cao)(cao)(cao)草(cao)(cao)(cao)(cao)(cao)(cao)原(yuan)的(de)(de)代表類型(xing)。其(qi)次(ci)為百里香、鐵桿蒿(hao)、茭蒿(hao)、委陵菜等。經(jing)幾年(nian)來的(de)(de)保(bao)(bao)護(hu)(hu)，草(cao)(cao)(cao)(cao)(cao)(cao)場生(sheng)產力已由畝產鮮草(cao)(cao)(cao)(cao)(cao)(cao)100～150千克(ke)提高(gao)到400～600千克(ke)，是良(liang)好的(de)(de)常年(nian)牧場。

歷史

1982年，固原縣在云霧山(shan)建(jian)立(li)了面積達4000公(gong)頃的(de)草原自(zi)(zi)然保(bao)護(hu)區(qu)(qu)，1995年被列為省(區(qu)(qu))級(ji)自(zi)(zi)然保(bao)護(hu)區(qu)(qu)，這也是我(wo)國黃土高(gao)原建(jian)立(li)的(de)第(di)一個草地類自(zi)(zi)然保(bao)護(hu)區(qu)(qu)。

地理環境

云霧山主

云(yun)霧山(shan)草原自然保護區(qu)峰海拔(ba)2128米，山(shan)基由白(bai)云(yun)巖(yan)、紅色(se)砂礫組成，土(tu)壤為地灰(hui)褐(he)土(tu)和淡黑壚土(tu)，生長草甸植被(bei)。

自然資源

保護(hu)區(qu)內有植(zhi)物(wu)51科(ke)131屬182種(zhong)，動物(wu)40科(ke)74屬80種(zhong)，益蟲14科(ke)28種(zhong)，蜘蛛5科(ke)7種(zhong)。保護(hu)區(qu)所保護(hu)的對象就(jiu)是這些草原植(zhi)被及其生態系(xi)統，包(bao)括氣(qi)候、土壤、昆蟲、野(ye)生動植(zhi)物(wu)、微生物(wu)等。

生態保護

自80年云霧山(shan)草(cao)原(yuan)(yuan)自然保護區自然風光代中(zhong)期于日本、美國(guo)(guo)、德國(guo)(guo)等生(sheng)(sheng)(sheng)態(tai)學(xue)(xue)、土(tu)壤(rang)學(xue)(xue)和生(sheng)(sheng)(sheng)物多樣(yang)性等方面的科(ke)學(xue)(xue)家開展了合作研(yan)究(jiu)(jiu)(jiu)(jiu)，目前已成(cheng)為(wei)中(zhong)國(guo)(guo)科(ke)學(xue)(xue)院水利部水土(tu)保持研(yan)究(jiu)(jiu)(jiu)(jiu)所、西北農(nong)林(lin)科(ke)技大(da)(da)(da)學(xue)(xue)、蘭州大(da)(da)(da)學(xue)(xue)、寧(ning)夏(xia)大(da)(da)(da)學(xue)(xue)草(cao)業科(ke)學(xue)(xue)研(yan)究(jiu)(jiu)(jiu)(jiu)與研(yan)究(jiu)(jiu)(jiu)(jiu)生(sheng)(sheng)(sheng)培養、農(nong)業部狐貍(li)野性化(hua)馴(xun)養和國(guo)(guo)家林(lin)業局退化(hua)生(sheng)(sheng)(sheng)態(tai)系統定(ding)位(wei)監測(ce)基地及全球氣候變化(hua)定(ding)位(wei)監測(ce)點(dian)，經過近30年的封(feng)禁和草(cao)原(yuan)(yuan)生(sheng)(sheng)(sheng)態(tai)系統定(ding)位(wei)監測(ce)研(yan)究(jiu)(jiu)(jiu)(jiu)，生(sheng)(sheng)(sheng)態(tai)經濟社會效益顯著，已成(cheng)為(wei)我國(guo)(guo)西部草(cao)原(yuan)(yuan)植被恢復(fu)與草(cao)原(yuan)(yuan)自然修(xiu)復(fu)的一(yi)個成(cheng)功典(dian)范，為(wei)國(guo)(guo)家退耕還(huan)林(lin)草(cao)與地方封(feng)山(shan)禁牧(mu)工(gong)程的實施(shi)提供了重要科(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)代初期(qi)(qi)，在區域考察的(de)(de)基礎(chu)上(shang)，我們(men)提(ti)出并(bing)在我國西部寧夏(xia)固原云霧山建(jian)立了(le)(le)最早的(de)(de)典型(xing)草(cao)(cao)(cao)(cao)(cao)(cao)原自然(ran)(ran)保(bao)(bao)護(hu)(hu)區，封(feng)(feng)(feng)禁(jin)(jin)(jin)保(bao)(bao)護(hu)(hu)面積由(you)0.23萬hm已擴大到(dao)1 萬hm。通(tong)過(guo)近30年(nian)(nian)封(feng)(feng)(feng)禁(jin)(jin)(jin)定(ding)位(wei)試驗，根據草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)退化(hua)程度(du)采(cai)取封(feng)(feng)(feng)禁(jin)(jin)(jin)、改良、補播等草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)建(jian)設技術途徑(jing)，使(shi)退化(hua)草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)植(zhi)被種(zhong)類(lei)成分(fen)、牧(mu)草(cao)(cao)(cao)(cao)(cao)(cao)生長(chang)發育和(he)(he)草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)生境條(tiao)件得(de)到(dao)了(le)(le)全面改善，草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)生產力有了(le)(le)很大提(ti)高(gao)，草(cao)(cao)(cao)(cao)(cao)(cao)群(qun)種(zhong)類(lei)成分(fen)發生了(le)(le)顯著(zhu)變化(hua)。封(feng)(feng)(feng)禁(jin)(jin)(jin)初期(qi)(qi)，草(cao)(cao)(cao)(cao)(cao)(cao)原植(zhi)物(wu)(wu)(wu)(wu)僅為53種(zhong)，其中(zhong)(zhong)灌(guan)木(mu)和(he)(he)半(ban)灌(guan)木(mu)占8%，草(cao)(cao)(cao)(cao)(cao)(cao)本占92%，多數以(yi)旱(han)(han)生植(zhi)物(wu)(wu)(wu)(wu)組成，物(wu)(wu)(wu)(wu)種(zhong)密度(du)平均為5種(zhong)/m。隨封(feng)(feng)(feng)禁(jin)(jin)(jin)期(qi)(qi)延(yan)長(chang)物(wu)(wu)(wu)(wu)種(zhong)密度(du)逐(zhu)(zhu)漸(jian)增(zeng)加(jia)，封(feng)(feng)(feng)禁(jin)(jin)(jin)的(de)(de)第(di)15年(nian)(nian)(1996年(nian)(nian))，物(wu)(wu)(wu)(wu)種(zhong)密度(du)達到(dao)了(le)(le)峰(feng)值(zhi)，平均為33種(zhong)/m，是未封(feng)(feng)(feng)禁(jin)(jin)(jin)的(de)(de)3.1倍(bei)，草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)群(qun)落物(wu)(wu)(wu)(wu)種(zhong)種(zhong)數達到(dao)186種(zhong)，是未封(feng)(feng)(feng)禁(jin)(jin)(jin)的(de)(de)3.5倍(bei)，其中(zhong)(zhong)灌(guan)木(mu)和(he)(he)半(ban)灌(guan)木(mu)占12%，草(cao)(cao)(cao)(cao)(cao)(cao)本占88%，多數以(yi)中(zhong)(zhong)生和(he)(he)中(zhong)(zhong)旱(han)(han)生植(zhi)物(wu)(wu)(wu)(wu)組成，并(bing)出現大量(liang)森林(lin)草(cao)(cao)(cao)(cao)(cao)(cao)原地(di)(di)帶(dai)的(de)(de)灌(guan)木(mu)和(he)(he)草(cao)(cao)(cao)(cao)(cao)(cao)本植(zhi)物(wu)(wu)(wu)(wu)種(zhong)。草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)覆(fu)蓋度(du)由(you)35%提(ti)高(gao)到(dao)95%，生物(wu)(wu)(wu)(wu)量(liang)由(you)750提(ti)高(gao)到(dao)7560kg/hm。特別是在1986和(he)(he)1991年(nian)(nian)降雨量(liang)274.8mm和(he)(he)259.7mm的(de)(de)大旱(han)(han)年(nian)(nian)份(fen)，寧夏(xia)固原2/3的(de)(de)地(di)(di)方(fang)由(you)于(yu)干旱(han)(han)缺草(cao)(cao)(cao)(cao)(cao)(cao)造成60%~70%牲畜死(si)亡(wang)，但(dan)封(feng)(feng)(feng)禁(jin)(jin)(jin)保(bao)(bao)護(hu)(hu)和(he)(he)改良草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)周圍的(de)(de)鄉村5.0~6.0萬頭(tou)牲畜得(de)到(dao)了(le)(le)挽救，直接減少(shao)經(jing)濟(ji)損(sun)失500萬元，充分(fen)發揮了(le)(le)"自然(ran)(ran)保(bao)(bao)護(hu)(hu)區"和(he)(he)改良草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)的(de)(de)顯著(zhu)作(zuo)用(yong)，保(bao)(bao)護(hu)(hu)區生態、經(jing)濟(ji)、社會效益(yi)顯著(zhu)，受(shou)到(dao)了(le)(le)各級政(zheng)府及群(qun)眾的(de)(de)一致贊揚，得(de)到(dao)了(le)(le)地(di)(di)方(fang)政(zheng)府表(biao)彰和(he)(he)獎勵(li)。但(dan)封(feng)(feng)(feng)禁(jin)(jin)(jin)15年(nian)(nian)后(hou)隨封(feng)(feng)(feng)禁(jin)(jin)(jin)時間的(de)(de)延(yan)長(chang)，物(wu)(wu)(wu)(wu)種(zhong)密度(du)趨于(yu)下(xia)降，第(di)24-28年(nian)(nian)(2008年(nian)(nian))物(wu)(wu)(wu)(wu)種(zhong)密度(du)僅為19.1種(zhong)/m。封(feng)(feng)(feng)禁(jin)(jin)(jin)期(qi)(qi)過(guo)長(chang)因枯草(cao)(cao)(cao)(cao)(cao)(cao)層(ceng)加(jia)厚而(er)影響草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)自然(ran)(ran)更新(xin)與物(wu)(wu)(wu)(wu)種(zhong)多樣(yang)性(xing)增(zeng)加(jia)。草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)土(tu)壤種(zhong)子(zi)庫研究表(biao)明，云霧山草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)土(tu)壤種(zhong)子(zi)庫在空(kong)間分(fen)布(bu)上(shang)呈現一定(ding)的(de)(de)規(gui)(gui)律(lv)性(xing)，種(zhong)子(zi)密度(du)在垂直分(fen)布(bu)上(shang)呈現出由(you)表(biao)層(ceng)土(tu)壤向深層(ceng)逐(zhu)(zhu)層(ceng)減少(shao)的(de)(de)變化(hua)規(gui)(gui)律(lv)，水平分(fen)布(bu)上(shang)變化(hua)規(gui)(gui)律(lv)為:封(feng)(feng)(feng)禁(jin)(jin)(jin)>放(fang)牧(mu);陰坡>陽坡;下(xia)坡>中(zhong)(zhong)坡>上(shang)坡，這些均是影響群(qun)落物(wu)(wu)(wu)(wu)種(zhong)多樣(yang)性(xing)增(zeng)加(jia)和(he)(he)草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)繁殖更新(xin)的(de)(de)關鍵(jian)問題。

通(tong)過(guo)近30年(nian)的(de)自然封禁試(shi)驗，明確提(ti)出草(cao)(cao)(cao)地(di)(di)(di)(di)(di)(di)恢(hui)復(fu)(fu)的(de)適(shi)宜(yi)封禁期:在(zai)半(ban)干旱區森林草(cao)(cao)(cao)原地(di)(di)(di)(di)(di)(di)帶，草(cao)(cao)(cao)甸植(zhi)(zhi)被的(de)適(shi)宜(yi)恢(hui)復(fu)(fu)期為3~5年(nian)，方(fang)可進(jin)行(xing)合理(li)的(de)放牧(mu)或刈割利(li)用(yong)(yong)，對利(li)用(yong)(yong)過(guo)度退(tui)(tui)化嚴重的(de)草(cao)(cao)(cao)甸植(zhi)(zhi)被在(zai)平水年(nian)需(xu)要封禁8~12年(nian);在(zai)典型(xing)草(cao)(cao)(cao)原地(di)(di)(di)(di)(di)(di)帶，草(cao)(cao)(cao)地(di)(di)(di)(di)(di)(di)植(zhi)(zhi)被適(shi)宜(yi)恢(hui)復(fu)(fu)期為5~8年(nian)，方(fang)可進(jin)行(xing)合理(li)刈割和放牧(mu)利(li)用(yong)(yong)，退(tui)(tui)化嚴重的(de)草(cao)(cao)(cao)地(di)(di)(di)(di)(di)(di)植(zhi)(zhi)被在(zai)平水年(nian)約需(xu)封禁10~15年(nian);在(zai)荒漠草(cao)(cao)(cao)原地(di)(di)(di)(di)(di)(di)帶，草(cao)(cao)(cao)地(di)(di)(di)(di)(di)(di)植(zhi)(zhi)被適(shi)宜(yi)恢(hui)復(fu)(fu)期為10~12年(nian)，方(fang)可進(jin)行(xing)合理(li)的(de)刈割和放牧(mu)利(li)用(yong)(yong)，退(tui)(tui)化嚴重草(cao)(cao)(cao)地(di)(di)(di)(di)(di)(di)在(zai)平水年(nian)約需(xu)封禁15~20年(nian)。這(zhe)一結論通(tong)過(guo)多年(nian)的(de)試(shi)驗驗證，已建立(li)了(le)示(shi)范樣板，為同類型(xing)區天然植(zhi)(zhi)被恢(hui)復(fu)(fu)利(li)用(yong)(yong)提(ti)供了(le)重要科學依據(ju)。

封禁草地自然演替過程與規律

通過(guo)近30年(nian)(nian)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)封(feng)(feng)禁試(shi)驗，首次劃分(fen)了(le)(le)草(cao)(cao)地植被恢(hui)復(fu)與(yu)(yu)時序演替過(guo)程，分(fen)為(wei)(wei)五(wu)個(ge)(ge)階(jie)(jie)(jie)段(duan)(duan):第(di)一階(jie)(jie)(jie)段(duan)(duan)為(wei)(wei)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)群(qun)(qun)(qun)持續增(zeng)(zeng)(zeng)長(chang)(chang)聚集階(jie)(jie)(jie)段(duan)(duan)，即在(zai)(zai)封(feng)(feng)禁的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)1~3年(nian)(nian)內(nei)以本氏(shi)針茅鄉(xiang)土種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)為(wei)(wei)主的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)建(jian)群(qun)(qun)(qun)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)與(yu)(yu)其它優(you)勢(shi)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)、伴生(sheng)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)和偶見種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)不斷(duan)適(shi)(shi)應(ying)(ying)新的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)生(sheng)境(jing)，各項(xiang)生(sheng)長(chang)(chang)指標穩(wen)定增(zeng)(zeng)(zeng)長(chang)(chang);第(di)二階(jie)(jie)(jie)段(duan)(duan)為(wei)(wei)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)間激(ji)烈競(jing)爭(zheng)(zheng)階(jie)(jie)(jie)段(duan)(duan)，也是封(feng)(feng)禁的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)第(di)4~9年(nian)(nian)，植物(wu)數(shu)(shu)(shu)量(liang)大(da)幅度增(zeng)(zeng)(zeng)長(chang)(chang)，并適(shi)(shi)應(ying)(ying)了(le)(le)新的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)生(sheng)境(jing)，且(qie)相互(hu)展(zhan)開了(le)(le)激(ji)烈的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)間競(jing)爭(zheng)(zheng)與(yu)(yu)自(zi)然選擇(ze);第(di)三階(jie)(jie)(jie)段(duan)(duan)為(wei)(wei)建(jian)群(qun)(qun)(qun)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)加速恢(hui)復(fu)演替階(jie)(jie)(jie)段(duan)(duan)，即封(feng)(feng)禁的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)10~15年(nian)(nian)，植物(wu)在(zai)(zai)激(ji)烈的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)間競(jing)爭(zheng)(zheng)中(zhong)"物(wu)競(jing)天擇(ze)、適(shi)(shi)者生(sheng)存"，本氏(shi)針茅形(xing)成(cheng)明顯建(jian)群(qun)(qun)(qun)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)，并不斷(duan)加速種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)群(qun)(qun)(qun)自(zi)身的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)恢(hui)復(fu)與(yu)(yu)擴展(zhan), 且(qie)已達到"亞(ya)頂極";第(di)四階(jie)(jie)(jie)段(duan)(duan)為(wei)(wei)建(jian)群(qun)(qun)(qun)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)定居生(sheng)長(chang)(chang)階(jie)(jie)(jie)段(duan)(duan)，封(feng)(feng)禁的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)16~21年(nian)(nian)本氏(shi)針茅種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)群(qun)(qun)(qun)個(ge)(ge)體數(shu)(shu)(shu)量(liang)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)變化基本穩(wen)定在(zai)(zai)19株(zhu)/m，占群(qun)(qun)(qun)落(luo)(luo)總(zong)數(shu)(shu)(shu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)90.5%，已達到"亞(ya)頂極";第(di)五(wu)階(jie)(jie)(jie)段(duan)(duan)22~28年(nian)(nian)本氏(shi)針茅種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)群(qun)(qun)(qun)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)生(sheng)長(chang)(chang)繁殖受枯草(cao)(cao)層的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)影響，個(ge)(ge)體數(shu)(shu)(shu)量(liang)急(ji)劇下降，優(you)勢(shi)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)大(da)針茅種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)群(qun)(qun)(qun)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)數(shu)(shu)(shu)量(liang)巨增(zeng)(zeng)(zeng)，密度為(wei)(wei)16~26株(zhu)/m，有替代本氏(shi)針茅的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)趨勢(shi)。同時在(zai)(zai)草(cao)(cao)原(yuan)(yuan)群(qun)(qun)(qun)落(luo)(luo)生(sheng)長(chang)(chang)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)溝道(dao)還出現大(da)量(liang)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)中(zhong)生(sheng)灌(guan)木，多(duo)為(wei)(wei)森林(lin)草(cao)(cao)原(yuan)(yuan)區成(cheng)分(fen)，已由(you)草(cao)(cao)原(yuan)(yuan)群(qun)(qun)(qun)落(luo)(luo)坡下部的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)陰坡或半(ban)陰坡以片狀分(fen)布，逐漸向草(cao)(cao)原(yuan)(yuan)腹地呈零星(xing)狀入(ru)侵，使(shi)草(cao)(cao)原(yuan)(yuan)群(qun)(qun)(qun)落(luo)(luo)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)演替進入(ru)了(le)(le)一個(ge)(ge)重(zhong)要的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)階(jie)(jie)(jie)段(duan)(duan)，形(xing)成(cheng)了(le)(le)一個(ge)(ge)明顯的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)拐點，直到封(feng)(feng)禁的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)第(di)28年(nian)(nian)物(wu)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)豐富(fu)度仍保(bao)持在(zai)(zai)148種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)，具有典型草(cao)(cao)原(yuan)(yuan)群(qun)(qun)(qun)落(luo)(luo)向森林(lin)草(cao)(cao)原(yuan)(yuan)群(qun)(qun)(qun)落(luo)(luo)類型演替發展(zhan)的(de)(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(huang)土高原(yuan)典型草(cao)原(yuan)地(di)(di)(di)帶，通過不(bu)同刈(yi)割強度(du)試(shi)驗，表明(ming)適度(du)刈(yi)割可使草(cao)地(di)(di)(di)保持(chi)較高的物種(zhong)多樣性和生(sheng)產力，并能促(cu)進草(cao)地(di)(di)(di)物質平(ping)衡及(ji)良性循(xun)環，為封禁草(cao)地(di)(di)(di)的合理刈(yi)割利(li)用提供了重要依據。