芒果视频下载

云(yun)霧山自(zi)然(ran)保(bao)(bao)護(hu)(hu)區(qu)（Yunwushan Nature Re-Serve） 中(zhong)國第(di)2個草(cao)(cao)原(yuan)(yuan)(yuan)保(bao)(bao)護(hu)(hu)區(qu)。屬黃土高(gao)原(yuan)(yuan)(yuan)長芒草(cao)(cao)群系保(bao)(bao)留較好(hao)的(de)典型地區(qu)，對開展(zhan)草(cao)(cao)原(yuan)(yuan)(yuan)生(sheng)態系統(tong)的(de)定(ding)位研(yan)究，探索草(cao)(cao)原(yuan)(yuan)(yuan)、畜牧(mu)、水(shui)土保(bao)(bao)持間的(de)關系有重(zhong)要科研(yan)價值。位于寧(ning)夏固原(yuan)(yuan)(yuan)縣東北(bei)，為中(zhong)溫帶半干旱(han)黃土丘陵低(di)山區(qu)。已劃定(ding)自(zi)然(ran)保(bao)(bao)護(hu)(hu)區(qu)面積1300公(gong)頃(qing)。海拔多在1800～1900米(mi)，頂峰(feng)2148米(mi)。年均溫6℃，年降(jiang)水(shui)量約350～400毫米(mi)，土壤主要為淡黑(hei)壚土。有種(zhong)(zhong)(zhong)(zhong)子植(zhi)(zhi)物(wu)181種(zhong)(zhong)(zhong)(zhong)，其中(zhong)草(cao)(cao)本植(zhi)(zhi)物(wu)140多種(zhong)(zhong)(zhong)(zhong)，包(bao)括(kuo)飼用植(zhi)(zhi)物(wu)110種(zhong)(zhong)(zhong)(zhong)，藥用植(zhi)(zhi)物(wu)41種(zhong)(zhong)(zhong)(zhong)；脊椎動物(wu)80種(zhong)(zhong)(zhong)(zhong)。共有典型草(cao)(cao)原(yuan)(yuan)(yuan)、草(cao)(cao)甸草(cao)(cao)原(yuan)(yuan)(yuan)、荒漠草(cao)(cao)原(yuan)(yuan)(yuan)、中(zhong)生(sheng)落葉(xie)闊葉(xie)灌叢和耐旱(han)落葉(xie)灌叢等5個植(zhi)(zhi)被亞(ya)型，11個重(zhong)要群系。其中(zhong)以(yi)典型草(cao)(cao)原(yuan)(yuan)(yuan)的(de)長芒草(cao)(cao)群系占優(you)勢，為黃土高(gao)原(yuan)(yuan)(yuan)叢生(sheng)禾草(cao)(cao)草(cao)(cao)原(yuan)(yuan)(yuan)的(de)代表類型。其次為百里香、鐵(tie)桿蒿(hao)、茭蒿(hao)、委(wei)陵菜(cai)等。經幾(ji)年來(lai)的(de)保(bao)(bao)護(hu)(hu)，草(cao)(cao)場生(sheng)產力(li)已由畝產鮮草(cao)(cao)100～150千(qian)(qian)克提高(gao)到(dao)400～600千(qian)(qian)克，是良好(hao)的(de)常年牧(mu)場。

歷史

1982年(nian)，固原(yuan)縣(xian)在(zai)云(yun)霧山建(jian)立了面積達4000公頃(qing)的(de)草原(yuan)自然(ran)(ran)保護區(qu)，1995年(nian)被列為省(區(qu))級(ji)自然(ran)(ran)保護區(qu)，這也是(shi)我國黃土高原(yuan)建(jian)立的(de)第(di)一個草地(di)類自然(ran)(ran)保護區(qu)。

地理環境

云霧山主

云(yun)霧山草原自然(ran)保護區峰海(hai)拔(ba)2128米，山基(ji)由白云(yun)巖(yan)、紅色砂礫組成，土壤(rang)為地灰褐土和淡黑(hei)壚土，生長草甸(dian)植被。

自然資源

保護(hu)區(qu)內(nei)有植(zhi)(zhi)物51科131屬(shu)182種(zhong)，動物40科74屬(shu)80種(zhong)，益蟲14科28種(zhong)，蜘蛛5科7種(zhong)。保護(hu)區(qu)所保護(hu)的對象就(jiu)是這些草原植(zhi)(zhi)被(bei)及(ji)其生(sheng)態系統(tong)，包括(kuo)氣(qi)候、土壤、昆蟲、野生(sheng)動植(zhi)(zhi)物、微生(sheng)物等。

生態保護

自80年云霧山草(cao)(cao)原(yuan)自然(ran)(ran)保護區自然(ran)(ran)風光(guang)代(dai)中期(qi)于日本(ben)、美國、德國等(deng)生(sheng)態(tai)(tai)學(xue)、土壤學(xue)和生(sheng)物多樣性等(deng)方(fang)面的(de)科(ke)學(xue)家(jia)(jia)開展(zhan)了(le)合作研(yan)(yan)究(jiu)(jiu)，目前已成(cheng)為中國科(ke)學(xue)院水利部(bu)水土保持研(yan)(yan)究(jiu)(jiu)所、西(xi)北農林科(ke)技大學(xue)、蘭州大學(xue)、寧夏大學(xue)草(cao)(cao)業(ye)科(ke)學(xue)研(yan)(yan)究(jiu)(jiu)與(yu)研(yan)(yan)究(jiu)(jiu)生(sheng)培養(yang)(yang)、農業(ye)部(bu)狐(hu)貍野(ye)性化馴(xun)養(yang)(yang)和國家(jia)(jia)林業(ye)局(ju)退化生(sheng)態(tai)(tai)系統定(ding)位(wei)監(jian)測(ce)基地(di)及全(quan)球氣候變化定(ding)位(wei)監(jian)測(ce)點，經過近30年的(de)封禁(jin)和草(cao)(cao)原(yuan)生(sheng)態(tai)(tai)系統定(ding)位(wei)監(jian)測(ce)研(yan)(yan)究(jiu)(jiu)，生(sheng)態(tai)(tai)經濟社會效益顯著(zhu)，已成(cheng)為我國西(xi)部(bu)草(cao)(cao)原(yuan)植被恢復與(yu)草(cao)(cao)原(yuan)自然(ran)(ran)修復的(de)一(yi)個成(cheng)功(gong)典(dian)范，為國家(jia)(jia)退耕還林草(cao)(cao)與(yu)地(di)方(fang)封山禁(jin)牧(mu)工程的(de)實施(shi)提供了(le)重要科(ke)學(xue)依(yi)據。

天然草地自然修復成效顯著

20世紀80年(nian)(nian)(nian)代初期，在(zai)(zai)區(qu)域考察的(de)(de)基礎上(shang)(shang)，我們提(ti)出(chu)(chu)并(bing)在(zai)(zai)我國西部(bu)寧夏(xia)固(gu)原(yuan)(yuan)云(yun)霧(wu)山建(jian)立了(le)(le)最早(zao)的(de)(de)典型草(cao)(cao)(cao)(cao)(cao)(cao)原(yuan)(yuan)自然保(bao)護(hu)區(qu)，封(feng)(feng)(feng)(feng)禁(jin)保(bao)護(hu)面積由(you)(you)0.23萬hm已擴大(da)(da)到(dao)1 萬hm。通過近30年(nian)(nian)(nian)封(feng)(feng)(feng)(feng)禁(jin)定位試驗，根據草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)退化(hua)程度(du)采取封(feng)(feng)(feng)(feng)禁(jin)、改良、補(bu)播等草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)建(jian)設(she)技術途徑，使退化(hua)草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)植(zhi)被種(zhong)(zhong)(zhong)類(lei)成分(fen)、牧(mu)草(cao)(cao)(cao)(cao)(cao)(cao)生(sheng)長(chang)(chang)發育和(he)草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)生(sheng)境條件得(de)到(dao)了(le)(le)全面改善(shan)，草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)生(sheng)產力有了(le)(le)很大(da)(da)提(ti)高，草(cao)(cao)(cao)(cao)(cao)(cao)群(qun)種(zhong)(zhong)(zhong)類(lei)成分(fen)發生(sheng)了(le)(le)顯著變化(hua)。封(feng)(feng)(feng)(feng)禁(jin)初期，草(cao)(cao)(cao)(cao)(cao)(cao)原(yuan)(yuan)植(zhi)物(wu)(wu)(wu)(wu)僅為53種(zhong)(zhong)(zhong)，其(qi)中(zhong)灌(guan)木(mu)和(he)半(ban)灌(guan)木(mu)占8%，草(cao)(cao)(cao)(cao)(cao)(cao)本(ben)占92%，多(duo)(duo)數(shu)以(yi)旱(han)生(sheng)植(zhi)物(wu)(wu)(wu)(wu)組成，物(wu)(wu)(wu)(wu)種(zhong)(zhong)(zhong)密(mi)(mi)(mi)度(du)平均(jun)(jun)為5種(zhong)(zhong)(zhong)/m。隨封(feng)(feng)(feng)(feng)禁(jin)期延長(chang)(chang)物(wu)(wu)(wu)(wu)種(zhong)(zhong)(zhong)密(mi)(mi)(mi)度(du)逐(zhu)漸增加(jia)，封(feng)(feng)(feng)(feng)禁(jin)的(de)(de)第15年(nian)(nian)(nian)(1996年(nian)(nian)(nian))，物(wu)(wu)(wu)(wu)種(zhong)(zhong)(zhong)密(mi)(mi)(mi)度(du)達到(dao)了(le)(le)峰值(zhi)，平均(jun)(jun)為33種(zhong)(zhong)(zhong)/m，是未(wei)封(feng)(feng)(feng)(feng)禁(jin)的(de)(de)3.1倍，草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)群(qun)落(luo)物(wu)(wu)(wu)(wu)種(zhong)(zhong)(zhong)種(zhong)(zhong)(zhong)數(shu)達到(dao)186種(zhong)(zhong)(zhong)，是未(wei)封(feng)(feng)(feng)(feng)禁(jin)的(de)(de)3.5倍，其(qi)中(zhong)灌(guan)木(mu)和(he)半(ban)灌(guan)木(mu)占12%，草(cao)(cao)(cao)(cao)(cao)(cao)本(ben)占88%，多(duo)(duo)數(shu)以(yi)中(zhong)生(sheng)和(he)中(zhong)旱(han)生(sheng)植(zhi)物(wu)(wu)(wu)(wu)組成，并(bing)出(chu)(chu)現(xian)大(da)(da)量(liang)(liang)(liang)森林草(cao)(cao)(cao)(cao)(cao)(cao)原(yuan)(yuan)地(di)(di)帶的(de)(de)灌(guan)木(mu)和(he)草(cao)(cao)(cao)(cao)(cao)(cao)本(ben)植(zhi)物(wu)(wu)(wu)(wu)種(zhong)(zhong)(zhong)。草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)覆蓋(gai)度(du)由(you)(you)35%提(ti)高到(dao)95%，生(sheng)物(wu)(wu)(wu)(wu)量(liang)(liang)(liang)由(you)(you)750提(ti)高到(dao)7560kg/hm。特別(bie)是在(zai)(zai)1986和(he)1991年(nian)(nian)(nian)降雨量(liang)(liang)(liang)274.8mm和(he)259.7mm的(de)(de)大(da)(da)旱(han)年(nian)(nian)(nian)份，寧夏(xia)固(gu)原(yuan)(yuan)2/3的(de)(de)地(di)(di)方(fang)由(you)(you)于干旱(han)缺草(cao)(cao)(cao)(cao)(cao)(cao)造成60%~70%牲(sheng)畜(chu)死亡，但封(feng)(feng)(feng)(feng)禁(jin)保(bao)護(hu)和(he)改良草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)周圍(wei)的(de)(de)鄉(xiang)村5.0~6.0萬頭牲(sheng)畜(chu)得(de)到(dao)了(le)(le)挽救，直接減(jian)少(shao)經濟(ji)損失500萬元，充分(fen)發揮了(le)(le)"自然保(bao)護(hu)區(qu)"和(he)改良草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)的(de)(de)顯著作(zuo)用，保(bao)護(hu)區(qu)生(sheng)態、經濟(ji)、社會效益顯著，受到(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)府表彰和(he)獎勵。但封(feng)(feng)(feng)(feng)禁(jin)15年(nian)(nian)(nian)后(hou)隨封(feng)(feng)(feng)(feng)禁(jin)時間(jian)的(de)(de)延長(chang)(chang)，物(wu)(wu)(wu)(wu)種(zhong)(zhong)(zhong)密(mi)(mi)(mi)度(du)趨于下降，第24-28年(nian)(nian)(nian)(2008年(nian)(nian)(nian))物(wu)(wu)(wu)(wu)種(zhong)(zhong)(zhong)密(mi)(mi)(mi)度(du)僅為19.1種(zhong)(zhong)(zhong)/m。封(feng)(feng)(feng)(feng)禁(jin)期過長(chang)(chang)因枯草(cao)(cao)(cao)(cao)(cao)(cao)層加(jia)厚(hou)而影響(xiang)草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)自然更新與(yu)物(wu)(wu)(wu)(wu)種(zhong)(zhong)(zhong)多(duo)(duo)樣(yang)性(xing)增加(jia)。草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)土壤(rang)種(zhong)(zhong)(zhong)子庫(ku)研究表明，云(yun)霧(wu)山草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)土壤(rang)種(zhong)(zhong)(zhong)子庫(ku)在(zai)(zai)空(kong)間(jian)分(fen)布上(shang)(shang)呈現(xian)一定的(de)(de)規(gui)(gui)律性(xing)，種(zhong)(zhong)(zhong)子密(mi)(mi)(mi)度(du)在(zai)(zai)垂(chui)直分(fen)布上(shang)(shang)呈現(xian)出(chu)(chu)由(you)(you)表層土壤(rang)向(xiang)深層逐(zhu)層減(jian)少(shao)的(de)(de)變化(hua)規(gui)(gui)律，水平分(fen)布上(shang)(shang)變化(hua)規(gui)(gui)律為:封(feng)(feng)(feng)(feng)禁(jin)>放牧(mu);陰坡(po)(po)(po)(po)>陽坡(po)(po)(po)(po);下坡(po)(po)(po)(po)>中(zhong)坡(po)(po)(po)(po)>上(shang)(shang)坡(po)(po)(po)(po)，這些均(jun)(jun)是影響(xiang)群(qun)落(luo)物(wu)(wu)(wu)(wu)種(zhong)(zhong)(zhong)多(duo)(duo)樣(yang)性(xing)增加(jia)和(he)草(cao)(cao)(cao)(cao)(cao)(cao)地(di)(di)繁殖更新的(de)(de)關鍵問題。

通(tong)過近30年(nian)的(de)自然(ran)封(feng)禁(jin)(jin)試驗，明確提出草(cao)地(di)(di)(di)恢復的(de)適(shi)(shi)(shi)宜封(feng)禁(jin)(jin)期(qi)(qi):在(zai)半干旱(han)區森林(lin)草(cao)原(yuan)(yuan)地(di)(di)(di)帶，草(cao)甸植(zhi)被的(de)適(shi)(shi)(shi)宜恢復期(qi)(qi)為3~5年(nian)，方可(ke)(ke)進行合理(li)的(de)放(fang)牧或刈割利(li)用(yong)，對利(li)用(yong)過度退(tui)化嚴(yan)重(zhong)的(de)草(cao)甸植(zhi)被在(zai)平(ping)水年(nian)需要封(feng)禁(jin)(jin)8~12年(nian);在(zai)典型草(cao)原(yuan)(yuan)地(di)(di)(di)帶，草(cao)地(di)(di)(di)植(zhi)被適(shi)(shi)(shi)宜恢復期(qi)(qi)為5~8年(nian)，方可(ke)(ke)進行合理(li)刈割和放(fang)牧利(li)用(yong)，退(tui)化嚴(yan)重(zhong)的(de)草(cao)地(di)(di)(di)植(zhi)被在(zai)平(ping)水年(nian)約需封(feng)禁(jin)(jin)10~15年(nian);在(zai)荒漠草(cao)原(yuan)(yuan)地(di)(di)(di)帶，草(cao)地(di)(di)(di)植(zhi)被適(shi)(shi)(shi)宜恢復期(qi)(qi)為10~12年(nian)，方可(ke)(ke)進行合理(li)的(de)刈割和放(fang)牧利(li)用(yong)，退(tui)化嚴(yan)重(zhong)草(cao)地(di)(di)(di)在(zai)平(ping)水年(nian)約需封(feng)禁(jin)(jin)15~20年(nian)。這一結論通(tong)過多年(nian)的(de)試驗驗證，已(yi)建(jian)立了(le)示范樣板(ban)，為同類型區天然(ran)植(zhi)被恢復利(li)用(yong)提供了(le)重(zhong)要科學依據。

封禁草地自然演替過程與規律

通過近30年(nian)(nian)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)封(feng)禁(jin)試驗，首(shou)次劃(hua)分了(le)草(cao)(cao)(cao)地植被(bei)恢(hui)復與(yu)(yu)時序演替過程，分為五(wu)個(ge)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)(duan):第一階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)(duan)為種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)群(qun)(qun)(qun)持(chi)續(xu)增(zeng)長聚集(ji)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)(duan)，即在(zai)(zai)封(feng)禁(jin)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)1~3年(nian)(nian)內以(yi)本(ben)(ben)(ben)氏(shi)針(zhen)茅鄉土種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)為主(zhu)的(de)(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)不斷適應(ying)新的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)生(sheng)境，各項(xiang)生(sheng)長指標(biao)穩定增(zeng)長;第二階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)(duan)為種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)間(jian)激(ji)烈競爭(zheng)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)(duan)，也(ye)是封(feng)禁(jin)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)第4~9年(nian)(nian)，植物數量(liang)大幅度增(zeng)長，并(bing)適應(ying)了(le)新的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)生(sheng)境，且(qie)相互展開了(le)激(ji)烈的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)間(jian)競爭(zheng)與(yu)(yu)自(zi)然選擇;第三階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)(duan)為建(jian)群(qun)(qun)(qun)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)加速恢(hui)復演替階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)(duan)，即封(feng)禁(jin)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)10~15年(nian)(nian)，植物在(zai)(zai)激(ji)烈的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)間(jian)競爭(zheng)中"物競天擇、適者生(sheng)存"，本(ben)(ben)(ben)氏(shi)針(zhen)茅形成明顯建(jian)群(qun)(qun)(qun)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)，并(bing)不斷加速種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)群(qun)(qun)(qun)自(zi)身的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)恢(hui)復與(yu)(yu)擴展, 且(qie)已達到(dao)(dao)"亞(ya)頂極(ji)";第四階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)(duan)為建(jian)群(qun)(qun)(qun)種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)定居生(sheng)長階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)(duan)，封(feng)禁(jin)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)16~21年(nian)(nian)本(ben)(ben)(ben)氏(shi)針(zhen)茅種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)群(qun)(qun)(qun)個(ge)體數量(liang)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)變(bian)化基(ji)本(ben)(ben)(ben)穩定在(zai)(zai)19株(zhu)/m，占群(qun)(qun)(qun)落(luo)總數的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)90.5%，已達到(dao)(dao)"亞(ya)頂極(ji)";第五(wu)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)(duan)22~28年(nian)(nian)本(ben)(ben)(ben)氏(shi)針(zhen)茅種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)群(qun)(qun)(qun)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)生(sheng)長繁殖受枯(ku)草(cao)(cao)(cao)層的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)影(ying)響，個(ge)體數量(liang)急劇下(xia)降，優(you)勢種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)大針(zhen)茅種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)群(qun)(qun)(qun)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)數量(liang)巨增(zeng)，密度為16~26株(zhu)/m，有(you)替代本(ben)(ben)(ben)氏(shi)針(zhen)茅的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)趨勢。同(tong)時在(zai)(zai)草(cao)(cao)(cao)原(yuan)群(qun)(qun)(qun)落(luo)生(sheng)長的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)溝道還(huan)出(chu)現大量(liang)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)中生(sheng)灌木(mu)，多為森(sen)林(lin)草(cao)(cao)(cao)原(yuan)區成分，已由草(cao)(cao)(cao)原(yuan)群(qun)(qun)(qun)落(luo)坡下(xia)部的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)陰(yin)(yin)坡或(huo)半陰(yin)(yin)坡以(yi)片狀分布，逐漸(jian)向草(cao)(cao)(cao)原(yuan)腹(fu)地呈零(ling)星(xing)狀入(ru)侵，使(shi)草(cao)(cao)(cao)原(yuan)群(qun)(qun)(qun)落(luo)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)演替進(jin)入(ru)了(le)一個(ge)重要的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)階(jie)(jie)(jie)(jie)段(duan)(duan)(duan)(duan)，形成了(le)一個(ge)明顯的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)拐點，直到(dao)(dao)封(feng)禁(jin)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)第28年(nian)(nian)物種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)豐富度仍保持(chi)在(zai)(zai)148種(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)，具(ju)有(you)典型(xing)草(cao)(cao)(cao)原(yuan)群(qun)(qun)(qun)落(luo)向森(sen)林(lin)草(cao)(cao)(cao)原(yuan)群(qun)(qun)(qun)落(luo)類(lei)型(xing)演替發展的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)趨勢。

封禁草地適度刈割利用技術

在黃(huang)土(tu)高原典(dian)型草(cao)原地帶，通過不同(tong)刈割(ge)強度(du)試(shi)驗，表明適度(du)刈割(ge)可使草(cao)地保(bao)持較(jiao)高的(de)物種多樣性(xing)和生產力，并能(neng)促進草(cao)地物質平衡及良性(xing)循(xun)環，為封(feng)禁草(cao)地的(de)合理刈割(ge)利用(yong)提供了重要(yao)依據。