亚洲免费av电影一区二区三区,日韩爱爱视频,51精品视频一区二区三区,91视频爱爱,日韩欧美在线播放视频,中文字幕少妇AV,亚洲电影中文字幕,久久久久亚洲av成人网址,久久综合视频网站,国产在线不卡免费播放

        ?

        退化草地生態(tài)恢復(fù)研究案例綜合分析:年限、效果和方法

        2017-03-09 08:22:10尚占環(huán)董世魁周華坤董全民龍瑞軍
        生態(tài)學(xué)報(bào) 2017年24期
        關(guān)鍵詞:長(zhǎng)期性年限草地

        尚占環(huán),董世魁,周華坤,董全民,龍瑞軍

        1 蘭州大學(xué)生命科學(xué)學(xué)院,草地農(nóng)業(yè)生態(tài)系統(tǒng)國(guó)家重點(diǎn)實(shí)驗(yàn)室,蘭州 730000 2 北京師范大學(xué)環(huán)境學(xué)院,北京 100875 3 中國(guó)科學(xué)院西北高原生物研究所,青海省寒區(qū)恢復(fù)生態(tài)學(xué)重點(diǎn)實(shí)驗(yàn)室,西寧 810008 4 青海大學(xué)畜牧獸醫(yī)科學(xué)院,西寧 810016

        在過去的一個(gè)世紀(jì),全球草地生態(tài)系統(tǒng)經(jīng)歷著有人類以來最為嚴(yán)重的威脅。這種威脅導(dǎo)致了大范圍和多形式的草地退化,其退化的結(jié)果包括生物多樣性喪失、生態(tài)系統(tǒng)功能減弱、當(dāng)?shù)刭囈陨娴木用裆?jì)減少或淪為難民。近50a來,發(fā)展中國(guó)家步入生產(chǎn)高速發(fā)展的階段,草地生態(tài)系統(tǒng)亦趨工業(yè)化毀壞之后塵[1- 3]。大范圍的草地荒漠化、毒雜草化等等,都在更嚴(yán)峻威脅著占全球陸地面積25%的草原。例如,從本世紀(jì)初到現(xiàn)在,中國(guó)媒體一直宣稱中國(guó)有90%的草原處于退化狀態(tài)[4]。因此,全球退化草地生態(tài)恢復(fù)面臨著提高其生計(jì)維持功能、生態(tài)服務(wù)功能的巨大挑戰(zhàn)。

        生態(tài)學(xué)家,特別是恢復(fù)生態(tài)學(xué)家長(zhǎng)期以來一直關(guān)注退化草地生態(tài)系統(tǒng)的恢復(fù),并致力于研究和實(shí)踐工作[5- 7]。研究案例的年限與恢復(fù)效果,方法有效性有著緊密的聯(lián)系,對(duì)實(shí)踐的指導(dǎo)價(jià)值也不同。在生態(tài)恢復(fù)案例中,成功的生態(tài)恢復(fù)效果往往都基于長(zhǎng)期的研究經(jīng)驗(yàn)和積累[5]。因?yàn)闇?zhǔn)確和正確的評(píng)估草地植被演變必須基于長(zhǎng)期的監(jiān)測(cè)結(jié)果,這樣才能對(duì)生物多樣性,植被生態(tài)功能給予詳細(xì)評(píng)估,使制定的管理方案更可靠[8]。從歐美開始,較長(zhǎng)期的草地恢復(fù)生態(tài)學(xué)研究工作很早就得到重視和實(shí)施[9-12]。在長(zhǎng)期生態(tài)學(xué)研究中,一般界定長(zhǎng)期的時(shí)間范圍是20—50a間,或者更長(zhǎng)時(shí)間[13-14]。沒有長(zhǎng)期恢復(fù)經(jīng)驗(yàn)積累,不可能獲得很好的恢復(fù)效果,其結(jié)果很可能適得其反。突出考慮生態(tài)恢復(fù)的長(zhǎng)期性特征,更能警示我們政策制定者,慎重考慮政策對(duì)環(huán)境影響。更多的了解不同年限的生態(tài)恢復(fù)研究案例,可為我國(guó)目前大量的生態(tài)恢復(fù)工程提供借鑒,實(shí)現(xiàn)揚(yáng)長(zhǎng)避短、查漏補(bǔ)缺;還可以為客觀評(píng)估我國(guó)生態(tài)恢復(fù)工程提供參考。本文從調(diào)研的國(guó)內(nèi)外149個(gè)退化草地恢復(fù)研究案例出發(fā),對(duì)退化草地生態(tài)恢復(fù)的時(shí)間期限,方法,效果,及研究年限規(guī)律進(jìn)行綜合分析,以期給我們當(dāng)前退化草地生態(tài)恢復(fù)提供借鑒價(jià)值。

        1 退化草地生態(tài)恢復(fù)研究的時(shí)間、效果及分布

        1.1 時(shí)間范圍

        當(dāng)代生態(tài)學(xué)研究已經(jīng)突破傳統(tǒng)生態(tài)學(xué)研究范疇,從時(shí)間跨度之廣就能看出來。Jackson[15]認(rèn)為生態(tài)學(xué)研究中的時(shí)間問題,分real time、Q-time (quaternary)和deep-time;第一個(gè)是一般的生態(tài)學(xué)研究時(shí)間范圍,從幾周到幾十年范圍內(nèi),主要包括競(jìng)爭(zhēng),捕食等;第二個(gè)是從100年到1萬年之間,包括演替、遷移、穩(wěn)定性,保護(hù)和滅絕等;第三個(gè)范圍超過1萬年,是古生物學(xué),進(jìn)化,地理變化范疇的研究。根據(jù)這個(gè)劃分,恢復(fù)生態(tài)學(xué),特別是草地恢復(fù)生態(tài)學(xué)一般屬于real time時(shí)間范疇,即大多數(shù)在幾十年范圍內(nèi),也少有案例超過100a。與森林相比,退化草地得到恢復(fù)的時(shí)間相對(duì)較短,因此大多草地生態(tài)學(xué)研究時(shí)間跨度也較短。

        雖然,長(zhǎng)期生態(tài)學(xué)研究的時(shí)間界定一般認(rèn)為是20—50a之間[13-14]。與時(shí)間尺度有關(guān)的退化草地生態(tài)恢復(fù)研究案例主要側(cè)重于對(duì)恢復(fù)技術(shù)實(shí)施后的監(jiān)測(cè),根據(jù)監(jiān)測(cè)結(jié)果來評(píng)判恢復(fù)效果。根據(jù)ISI Web of Science數(shù)據(jù)庫中,隨機(jī)獲取的149個(gè)關(guān)于草地恢復(fù)的研究案例中,大多數(shù)的時(shí)間尺度都小于10a,也就是大多數(shù)案例根據(jù)較短期的時(shí)間研究結(jié)果來評(píng)估退化草地恢復(fù)(圖1)。其次的時(shí)間尺度在10—20a之內(nèi)也較多,這些案例主要集中于較長(zhǎng)期的連續(xù)監(jiān)測(cè)(圖1)。恢復(fù)生態(tài)學(xué)中,長(zhǎng)期性研究手段主要有3個(gè),第一是相同樣地的長(zhǎng)期連續(xù)性監(jiān)測(cè)(long-term);第二是多年代序列樣地(chronosequence)的比較性分析;第三個(gè)是間斷性研究樣地的重訪研究。在大于20多年的研究案例中,多數(shù)是關(guān)于退化草地恢復(fù)后,通過再訪途徑獲得評(píng)估,一般是根據(jù)案例的文獻(xiàn)或者資料記載來進(jìn)行試驗(yàn)地重訪 (revisiting)(圖1)。

        圖1 隨機(jī)調(diào)查的149個(gè)草地恢復(fù)研究案例在不同年限段的數(shù)量分布Fig.1 The numbers pattern in different period (years) of 149 study cases of degraded grassland restoration

        圖2 隨機(jī)調(diào)查的149個(gè)退化草地恢復(fù)案例的恢復(fù)效果Fig.2 Evaluation of restoring effect for 149 grassland restoration cases

        1.2 恢復(fù)的效果

        在對(duì)149個(gè)草地恢復(fù)研究案例的綜合比較中,根據(jù)恢復(fù)目標(biāo)和最終達(dá)到的效果進(jìn)行了人為評(píng)分,評(píng)分從-5到+5,代表恢復(fù)技術(shù)實(shí)施后負(fù)作用和正作用的程度。從統(tǒng)計(jì)結(jié)果看(圖2),恢復(fù)結(jié)果與恢復(fù)年限并沒有關(guān)系,短期和長(zhǎng)期的恢復(fù)結(jié)果都有好有壞。說明了適宜的恢復(fù)技術(shù)與恢復(fù)時(shí)間相適應(yīng)的重要性??傮w來看,大于5a的生態(tài)恢復(fù)效果都較好,年限越長(zhǎng)草地恢復(fù)越趨于向良性方向演替。對(duì)于恢復(fù)技術(shù)而言,退化草地的恢復(fù)盡量采用排除干擾的方法,一般都能達(dá)到很好的效果,其結(jié)果的顯著性決定于年限長(zhǎng)短[16-19]。這也提示我們,目前在我國(guó)實(shí)施的各種退化草地恢復(fù)技術(shù)短期內(nèi)的效果評(píng)估難以代表對(duì)技術(shù)真實(shí)評(píng)價(jià),需要長(zhǎng)期跟蹤及再評(píng)估,才能獲得對(duì)生態(tài)恢復(fù)作用的深入認(rèn)識(shí)。

        不同草地類型、恢復(fù)技術(shù),以及對(duì)不同觀測(cè)對(duì)象產(chǎn)生的結(jié)果差別較大。在產(chǎn)生負(fù)結(jié)果的案例中主要集中于目標(biāo)物種/群落結(jié)構(gòu)的恢復(fù)[20-21]、土壤功能或氮水平的恢復(fù)[10,22],無機(jī)碳[23]。植被覆蓋度降低的案例中集中于8—9a期限中[24]。而較長(zhǎng)期土壤系統(tǒng)恢復(fù)(72a)一般都很難達(dá)到目標(biāo),這與氣候環(huán)境變動(dòng)有關(guān)[10]。相對(duì)而言,在草地生他系統(tǒng)中,針對(duì)生物多樣性和植被覆蓋度,一般適宜的恢復(fù)技術(shù)都能實(shí)現(xiàn)[11, 25-31]。而強(qiáng)干擾的措施一般都或多或少的在某個(gè)方面偏離預(yù)期目標(biāo),如放牧[29-30],火燒[25],施肥[32],耕作[10, 33],刈割[34]。從植被類型來看,沙化草地、干旱草地,在采取恢復(fù)措施后都能體現(xiàn)出正的恢復(fù)效應(yīng)[35-40 ],但是對(duì)于草甸、濕地草地,海邊草地而言,其結(jié)果較不確定[20-21, 34,36, 41-44,]??傮w而言,物種豐富度較高,土壤水、養(yǎng)分異質(zhì)性較高的草地變化不確定較高,并且難以預(yù)測(cè)。

        1.3 研究案例在全球分布及年限格局

        圖3 調(diào)研案例全球分布(澳洲,非洲,美洲,歐洲和亞洲)及年限格局Fig.3 All 149 study cases′ pattern in different continents (Australia, Africa, America, Europe and Asia) and periods (years)

        退化草地恢復(fù)長(zhǎng)期性研究案例年限與研究地區(qū)、國(guó)家的科研能力有很大關(guān)系(圖3)。歐洲研究基礎(chǔ)設(shè)施較完善,并且擁有較多的長(zhǎng)期性研究定位工作站,因此現(xiàn)有的報(bào)道中歐洲在不同年限都有很多案例,并且伴隨著時(shí)間的推移這些案例都將成為較長(zhǎng)年限案例。美洲主要集中在美國(guó)、加拿大的研究,近些年的長(zhǎng)期性研究快速發(fā)展,并且隨著美國(guó)長(zhǎng)期性生態(tài)學(xué)研究計(jì)劃的實(shí)施,會(huì)更加加強(qiáng)。亞洲關(guān)于草地恢復(fù)的研究主要分布在中國(guó),混合了長(zhǎng)期性定位研究和多次重訪案例,以及多年代比較性工作,近些年隨著中國(guó)科研投入的增加逐漸得到豐富和完善。澳洲和非洲的案例相對(duì)較少,但是澳洲退化草地恢復(fù)長(zhǎng)期性工作堅(jiān)持較好,而且研究?jī)?nèi)容也非常豐富,值得我們借鑒。

        2 長(zhǎng)期性退化草地生態(tài)恢復(fù)的目標(biāo)和措施

        2.1 恢復(fù)目標(biāo)

        退化草地生態(tài)恢復(fù)目標(biāo)與其他生態(tài)系統(tǒng)恢復(fù)目標(biāo)都相似,都集中于兩種功能,即生態(tài)功能、生產(chǎn)功能,但在具體研究案例中,有較詳細(xì)的區(qū)分[5]。在隨機(jī)調(diào)研的149個(gè)案例中,生物多樣性(29.48%)、植被覆蓋度(24.28%)、土壤碳庫(13.87%)3個(gè)恢復(fù)目標(biāo)占大多數(shù),其余恢復(fù)目標(biāo),如生產(chǎn)力,昆蟲群落,土壤微生物,土壤氮庫,目標(biāo)物種,植物群落結(jié)構(gòu),土壤種子庫,土壤濕度,飼用牧草等都相對(duì)較少(圖4)。實(shí)際案例中更多的是多個(gè)目標(biāo)的恢復(fù),例如植被覆蓋度和生產(chǎn)力[45-47],生物多樣性與生產(chǎn)力[48],在案例中很少有單一的恢復(fù)目標(biāo)。很多研究中,恢復(fù)目標(biāo)或多或少與研究對(duì)象生態(tài)生物學(xué)特點(diǎn)和研究者擅長(zhǎng)領(lǐng)域相關(guān),例如土壤種子庫、群落結(jié)構(gòu)穩(wěn)定性等,而植被覆蓋度永遠(yuǎn)是恒定的指標(biāo),在各年限研究案例都存在。

        圖4 隨機(jī)調(diào)查的149個(gè)退化草地生態(tài)恢復(fù)不同目標(biāo)占案例總數(shù)的百分比Fig.4 The ratio (%) of each restoring role in all grassland restoration cases (149)

        調(diào)查的研究案例中,在恢復(fù)年限與恢復(fù)目標(biāo)中沒有一致的規(guī)律性。在歐美國(guó)家的案例中,更多是關(guān)于生物多樣性,他們認(rèn)為生物多樣性如果能夠恢復(fù)的話,那么其他諸如生產(chǎn)力,目標(biāo)物種,土壤養(yǎng)分等功能都能隨之恢復(fù),這種思想實(shí)際上一直主導(dǎo)著當(dāng)前生態(tài)恢復(fù)理論與實(shí)踐[5, 49-50]。而在生物多樣性恢復(fù)的實(shí)踐中,當(dāng)前更側(cè)重于生態(tài)系統(tǒng)的管理[38,46, 51-52]。調(diào)查的研究案例中,生物多樣性恢復(fù)研究年限在長(zhǎng)期生態(tài)研究中較多,例如在澳大利亞,研究開墾的草地在棄耕后生物多樣性恢復(fù)達(dá)到80a[53]。北美斯泰普草地棄耕監(jiān)測(cè)多樣性達(dá)50多年[54],歐洲控制實(shí)驗(yàn)中N素對(duì)草本植物多樣性恢復(fù)影響能監(jiān)測(cè)70a[21]。事實(shí)上大多數(shù)長(zhǎng)期生態(tài)恢復(fù)案例主要依靠的是定期或者不定期的監(jiān)測(cè)。

        比較而言,生產(chǎn)力恢復(fù)的研究案例一般時(shí)間都比較短,這說明長(zhǎng)期生態(tài)學(xué)研究中生態(tài)功能是首要的。生產(chǎn)力功能在一定時(shí)期內(nèi)受人類需求影響較大,暫時(shí)性特點(diǎn)較明顯。調(diào)查的研究案例中,關(guān)于生產(chǎn)力的案例都是少于5a的研究[46- 48,55],只有來自中國(guó)的一個(gè)案例監(jiān)測(cè)了24a后草地恢復(fù)的生產(chǎn)力[33]。事實(shí)上我國(guó)目前正在綜合各種長(zhǎng)期性監(jiān)測(cè)研究對(duì)生態(tài)恢復(fù)的長(zhǎng)期性效果、規(guī)律,進(jìn)行更大范圍的總結(jié),爭(zhēng)取給全球提供更多參考。草地恢復(fù)中將土壤系統(tǒng)作為恢復(fù)考察對(duì)象基本上都在短、中、長(zhǎng)期年限都有,因此生態(tài)恢復(fù)始終將土壤系統(tǒng)視為關(guān)鍵[10, 22, 28,37, 44,56-60]。

        在以前的草地生態(tài)恢復(fù)研究案例中土壤微生物關(guān)注較少,隨著土壤微生物研究技術(shù)的發(fā)展,近些年關(guān)注較多[37, 40, 59, 61]。但是土壤微生物系統(tǒng)較為復(fù)雜,而且其恢復(fù)目標(biāo)難以把握,在生態(tài)恢復(fù)中可能作為參考指標(biāo),況且與土壤養(yǎng)分緊密相關(guān),一般與土壤養(yǎng)分一起作為整體考慮[37, 59]。作為近些年發(fā)展起來的綜合分析方法,現(xiàn)代統(tǒng)計(jì)學(xué)(例如多元統(tǒng)計(jì)、數(shù)量分析、結(jié)構(gòu)方程模型等)為植被-土壤養(yǎng)分-土壤微生物的關(guān)聯(lián)分析提供了手段,因此越來越多的生態(tài)恢復(fù)中土壤微生物成為熱點(diǎn)目標(biāo)。

        有兩篇研究涉及到了螞蟻[39]、蝴蝶[61]在草地生態(tài)恢復(fù)中的情況,這兩篇報(bào)告針對(duì)不同草地類型,不同恢復(fù)技術(shù),是草地生態(tài)恢復(fù)中考慮動(dòng)物,特別是昆蟲的典型案例。其中Menke在2015年的研究涉及了螞蟻群落在普列里,薩王納草地在封育恢復(fù)的短期(3a),中長(zhǎng)期(5—15a),以及大于15a的變化,很顯然年限長(zhǎng)的恢復(fù)對(duì)螞蟻群落恢復(fù)更有利[39]。關(guān)于蝴蝶的報(bào)告中,Woodrock 等人在2012年的報(bào)道中研究了草地開墾后采用人工播種恢復(fù),以及退化草地(灌叢化)清除灌叢等方法對(duì)蝴蝶的影響,其中棄耕人工播種對(duì)蝴蝶的恢復(fù)效果表現(xiàn)好些,這個(gè)研究年限是10a[61]。還有一個(gè)關(guān)于昆蟲群落的研究案例時(shí)間較長(zhǎng),前后間隔了40a,Schuch等人在2011年報(bào)告了德國(guó)東部干草原在控制木本方式下昆蟲群落恢復(fù)情況,并且效果很好[62]。

        2.2 恢復(fù)措施

        圖5 隨機(jī)調(diào)查的149個(gè)退化草地生態(tài)恢復(fù)不同恢復(fù)技術(shù)措施占案例總數(shù)的百分比Fig.5 The ratio (%) of each restoring technique in all grassland restoration cases (149)

        生態(tài)恢復(fù)技術(shù)一直是恢復(fù)生態(tài)工作者的重要研究方向,然而迄今為止,難以找到很通用的恢復(fù)技術(shù)。對(duì)于退化生態(tài)系統(tǒng)而言,最通用的途徑就是消除干擾,但是有時(shí)候消除干擾后漫長(zhǎng)的恢復(fù)時(shí)間,確實(shí)是人們難以堅(jiān)持,不得不尋求在景觀、生態(tài)功能方面更加快速的恢復(fù)技術(shù)。就退化草地生態(tài)系統(tǒng)而言,更多恢復(fù)技術(shù)集中于土壤-植物界面,因?yàn)椴莸刂脖粚悠鄬?duì)簡(jiǎn)單。從調(diào)查的149個(gè)研究案例可以看出,這些案例基本上涵蓋了地球上關(guān)于退化草地恢復(fù)的主要技術(shù)(圖5)。其中應(yīng)用最多的技術(shù)是人工補(bǔ)播或播種[36,46,55,59,63-69, ],圍欄禁牧(或禁止干擾)[11,18, 28,37,39,66,70-71,],放牧利用[24,29-30,36,42,72-74],刈割[41,75-80],施肥[20,32,77,81- 83 ]等技術(shù)。在澳大利亞火燒是常用的措施[25, 35],其他的技術(shù)如灌叢清除[61, 84],翻耕[33, 38],表土移植[44],木本防除[62],干草覆蓋[85],增加CO2[86],增水[26]等措施帶有很強(qiáng)的區(qū)域性,應(yīng)用不是很廣泛。

        調(diào)查的案例中,圍欄封育、人工播種,以及棄耕的恢復(fù)技術(shù),有較多的長(zhǎng)期研究案例[11,28, 53-54,59],其中對(duì)開墾草原的棄耕恢復(fù)研究是當(dāng)前的熱點(diǎn)內(nèi)容,這對(duì)在自然狀態(tài)下草原演替、草原群落建成等生態(tài)學(xué)重要性有關(guān)。調(diào)查的研究案例中火燒措施持續(xù)的時(shí)間都比較長(zhǎng),例如美國(guó)的林地草地火燒恢復(fù)研究持續(xù)了4a[87],美國(guó)高羊茅草地火燒恢復(fù)研究持續(xù)了5a[88],美國(guó)對(duì)林木入侵的草地恢復(fù)使用火燒恢復(fù)的研究持續(xù)了7a[89];澳大利亞南澳草地火燒技術(shù)恢復(fù)研究則持續(xù)了10a[25],瑞典干草原的火燒恢復(fù)研究持續(xù)了15a[35]。歐洲由于牧業(yè)利用需要,很多草地恢復(fù)技術(shù)集中在如何從草地上清除擴(kuò)張或侵入的灌木、林木,大多時(shí)候這種措施與放牧相結(jié)合[30],或者與人工播種結(jié)合[61]。

        在這些草地恢復(fù)技術(shù)中,值得注意的是人工播種(或人工種草)的技術(shù)應(yīng)用。這種技術(shù)一般在歐美國(guó)家是用來較快速的恢復(fù)草地生態(tài)功能,且采用本地的鄉(xiāng)土植物種子。同時(shí)一個(gè)非常重要的問題是,在已經(jīng)報(bào)道的歐美國(guó)家草地恢復(fù)中使用人工播種,一般都是混合播種,并且混播的物種都在10多種,甚至20、30種,很少有像我們國(guó)家采用的1種、2—3種、4—5種這樣少的混播技術(shù)應(yīng)用到草地生態(tài)恢復(fù)中[36,51,58-59,64,66,68,90]。在美國(guó)內(nèi)布拉斯加州一個(gè)草地人工種植恢復(fù)研究中,研究人員認(rèn)為15種的混播是低物種數(shù)的混播,同時(shí)他們采用了95種物種種子的混播作為高豐富度混播材料,這項(xiàng)研究用來分析人工混播群落的穩(wěn)定性和恢復(fù)能力[47]。但是,在我國(guó)人工播種恢復(fù)退化草地,采用混播草地植物物種非常少,甚至有時(shí)只有一種[91]。從生態(tài)學(xué)原理上,幾種草種混播做草地生態(tài)恢復(fù)應(yīng)該禁止,這樣會(huì)導(dǎo)致人工種植草地極其不穩(wěn)定,且造成再次退化,以致恢復(fù)工作投入的人力物力大量被浪費(fèi)。這也是我國(guó)草地人工恢復(fù)又迅速退化的一個(gè)非常重要原因[92]。

        3 退化草地生態(tài)恢復(fù)研究獲得長(zhǎng)期數(shù)據(jù)和結(jié)果的途徑

        3.1 連續(xù)監(jiān)測(cè)方法

        在我們調(diào)查的149個(gè)研究案例中,其中涉及到連續(xù)監(jiān)測(cè)方法的有66個(gè)(表1)。很顯然,連續(xù)監(jiān)測(cè)對(duì)長(zhǎng)期生態(tài)學(xué)研究十分重要,這對(duì)于研究的可信度,和更加清楚的認(rèn)識(shí)生態(tài)系統(tǒng)變化十分有用,但是這依賴于大量的人力、物力投入[33,109]。對(duì)退化草地生態(tài)恢復(fù)而言,連續(xù)的監(jiān)測(cè)有助于展示詳細(xì)恢復(fù)過程和提出更有效的管理措施。連續(xù)監(jiān)測(cè)面臨最大的挑戰(zhàn)是長(zhǎng)期資助項(xiàng)目,可持續(xù)的研究團(tuán)隊(duì)和經(jīng)費(fèi)支撐,這在全球都是十分困難的。隨著自動(dòng)化設(shè)備的發(fā)展,連續(xù)的監(jiān)測(cè)已經(jīng)變得越來越容易實(shí)現(xiàn)了。短期的研究很多能夠?qū)崿F(xiàn)連續(xù)監(jiān)測(cè),特別是每年或者每個(gè)月的觀測(cè)研究[41,55, 84]。越來越多的自動(dòng)化設(shè)備、遙感、氣象監(jiān)測(cè)等方法被應(yīng)用到連續(xù)的監(jiān)測(cè)中。

        完全采用連續(xù)監(jiān)測(cè)方法主要集中在短期的研究中,一般小于10a[30,43,47,55,84,94-96];也有長(zhǎng)于10a的連續(xù)監(jiān)測(cè)研究,這種研究除了依靠較穩(wěn)定的研究隊(duì)伍,經(jīng)費(fèi)資助外[16,26, 110],也依靠國(guó)家的持續(xù)監(jiān)測(cè)工程,例如中國(guó)內(nèi)蒙古一項(xiàng)研究連續(xù)持續(xù)了24a[33]。

        連續(xù)監(jiān)測(cè)或者調(diào)查方法也出現(xiàn)在定期、不定期重訪過程中。諸如對(duì)以前研究地點(diǎn),案例隔多少年以后重新再研究,那么可能在此期間開展連續(xù)2、3a或者更長(zhǎng)時(shí)間研究,來驗(yàn)證前期研究產(chǎn)生的結(jié)果(表1)。例如,Fritch等人[18],對(duì)于愛爾蘭集約化農(nóng)業(yè)利用的草地恢復(fù)過程中的研究,7a前恢復(fù)措施,在7a后連續(xù)開展了2a的調(diào)查。Matějková等人[24]對(duì)于希臘山地草地放牧恢復(fù)的8a研究中,其中后4a采用了連續(xù)調(diào)查方法。Maccherini 等人[36]在意大利對(duì)于鈣化草地恢復(fù)研究持續(xù)了9a,但是由于中間某種原因中斷了,其研究在開始和后來都采用了連續(xù)調(diào)查監(jiān)測(cè)的方法。Sykora等人[107]在荷蘭14a間的研究也是中間間隔了一段時(shí)間又重啟研究。Munson 和 Lauenroth[91]在對(duì)美國(guó)半干旱草地研究,持續(xù)了18a,但是采用了不定期重新調(diào)查方法,每次調(diào)查都堅(jiān)持2—3a的連續(xù)研究。Pavlu 等人[80]在德國(guó)草地研究持續(xù)了20a,只有中間一段時(shí)間連續(xù)了4a調(diào)查工作。更長(zhǎng)期的對(duì)比工作,例如Van Eekeren等人[111]在比利時(shí)草田輪作時(shí)間跨度36a,Bakker 等人[108]在北美間隔了50a,他們的工作都是很久以后重新連續(xù)調(diào)查。

        表1 研究案例中實(shí)地調(diào)查重復(fù)方法、年限及文獻(xiàn)來源

        3.2 定期重訪式方法

        實(shí)驗(yàn)案例的重訪研究是獲得生態(tài)恢復(fù)效果可靠性評(píng)估的有效有段。事實(shí)上,就研究的時(shí)間特點(diǎn),連續(xù)調(diào)查也屬于定期重訪,在這里定期重訪,特指一項(xiàng)研究持續(xù)進(jìn)行,但至少間隔時(shí)間以年為單位,進(jìn)行有規(guī)律的重新研究。在我們調(diào)查的149個(gè)研究案例中,這種嚴(yán)格定期重訪的案例不多,僅有7項(xiàng)(表1),可見定期重訪的方法應(yīng)用不是很廣泛。的確這需要很長(zhǎng)遠(yuǎn)研究計(jì)劃,和更為持續(xù)的人力、物力支撐。在我們調(diào)查7個(gè)案例中,共出現(xiàn)了3個(gè)研究報(bào)道,分別是Halpern 等人研究美國(guó)草地清除林木的影響,每隔兩年重復(fù)調(diào)查[87];在石楠灌叢草地研究工作,每隔3—4a定期重復(fù)調(diào)查,一共持續(xù)了17a[57];在英國(guó)集約化農(nóng)業(yè)利用草地恢復(fù)研究中每隔2a重復(fù)一次調(diào)查,一共持續(xù)了14a[32]。Schrautzer[79]在德國(guó)湖邊草地研究案例也采用了定期重訪方法,持續(xù)了28a,是在多年后重新在原來一個(gè)實(shí)驗(yàn)地點(diǎn)重新調(diào)查了10a,在這10a內(nèi)每隔2—3a調(diào)查一次。

        3.3 不定期重訪方法

        在草地生態(tài)恢復(fù)中,大多年限較長(zhǎng)的研究工作更多的依賴于不定期重復(fù)方法[19, 31,35, 37, 61, 83]。我們調(diào)查的案例中除了每年連續(xù)監(jiān)測(cè)案例,和定期重復(fù)案例,其余都與不定期重復(fù)方法有關(guān),更有82個(gè)案例是典型的不定期重復(fù)的研究工作(表1)。很顯然,不定期重復(fù)方法更符合當(dāng)前生態(tài)恢復(fù)研究工作的特點(diǎn)和人類認(rèn)識(shí)、人力/物力支撐現(xiàn)狀,相對(duì)而言信息量也較大。不僅在發(fā)達(dá)國(guó)家,這種方法應(yīng)用廣泛,而且在更多發(fā)展中國(guó)家和地區(qū),隨著社會(huì)穩(wěn)定,科學(xué)研究工作的興起,這種方法也得到了更多推廣和應(yīng)用[28, 37, 59]。在我們調(diào)查的案例中,不定期重訪集中在大于5a的研究案例中,也很多10a以上的研究案例(表1)。而混合了連續(xù)監(jiān)測(cè)的不定期重訪的研究案例更多的是10a以上的案例。

        不定期重訪方法在草地恢復(fù)研究中,從低成本、信息量、研究意義、可對(duì)比性等方面來說,非常值得推廣。事實(shí)上在草地恢復(fù)在演替過程中,連續(xù)監(jiān)測(cè)有時(shí)候非屬必要,畢竟自然演替,尤其在植被較穩(wěn)定階段,短期難以反映出變化。更長(zhǎng)年限的研究,如果想得到持續(xù)性結(jié)果,也只能通過不定期重訪方法,畢竟一代人、兩代人獲得可持續(xù)的研究支持十分有限。例如Gardner[11]研究新墨西哥荒漠草地間隔了30a;Kinucan 和Smeins[97]研究德克薩斯草地間隔了36a進(jìn)行重訪;Hejcman 等人[83]在捷克的研究間隔了37a重訪;Bakker等人[108]再次重訪并連續(xù)監(jiān)測(cè)相同樣地間隔了50a;Coffin等人[54]在北美重訪了53a前的斯泰普草地研究樣地;White等人[10]根據(jù)資料重訪了54a前和72a前的濱州草地樣地。這些長(zhǎng)時(shí)間跨度的研究都得到了很有意義的結(jié)果,對(duì)一個(gè)地區(qū)植被、管理都有很好的借鑒意義。較長(zhǎng)時(shí)間跨度的不定期重訪研究有一個(gè)特別要注意的事情,就是以前研究資料的可尋性,也就是必須能夠借助原來的資料能夠準(zhǔn)確的找到原來地點(diǎn),并且較詳細(xì)資料記載,否則其研究對(duì)比性難以把握。在有定位實(shí)驗(yàn)站條件的區(qū)域容易實(shí)現(xiàn),當(dāng)然在現(xiàn)在信息技術(shù)發(fā)展條件下,這樣的研究也比較容易實(shí)現(xiàn)。

        3.4 基于大數(shù)據(jù)的時(shí)間序列的建立與分析

        大數(shù)據(jù)分析的可靠性在于大量數(shù)據(jù)的統(tǒng)計(jì)趨勢(shì)性分析,基本上在草地恢復(fù)生態(tài)學(xué)研究中,一種是整合分析(Meta-analysis)的大數(shù)據(jù)統(tǒng)計(jì),另外一種是實(shí)地測(cè)量的大數(shù)據(jù)統(tǒng)計(jì)分析。大數(shù)據(jù)的時(shí)間序列分析,也必須建立在某種,或者各種實(shí)驗(yàn)調(diào)查基礎(chǔ)上。特別是對(duì)各種相似、相同方法研究的整合分析?,F(xiàn)在比較流行的meta分析方法,也很多是案例挖掘,采用研究結(jié)果的無量綱化后統(tǒng)一對(duì)比分析。在生態(tài)學(xué)領(lǐng)域,meta技術(shù)招致大量的批評(píng),導(dǎo)致很多單純的數(shù)據(jù)挖掘者,而非實(shí)驗(yàn)主義者[112-113]。在這里我們更推薦實(shí)地的meta技術(shù),也就是親自采用同一種方法調(diào)查,然后綜合對(duì)比分析。加拿大湯普森河大學(xué)大學(xué)(Thompson Rivers University)Fraser Lauchlan教授提出的“分散-協(xié)作-統(tǒng)一”的大數(shù)據(jù)整合的研究途徑(Coordinated distributed experiments)來獲取更多的生態(tài)數(shù)據(jù),這種方法具有方法統(tǒng)一性,跨區(qū)域性等特點(diǎn),是目前生態(tài)學(xué)大數(shù)據(jù)網(wǎng)絡(luò)研究的典范[114]。

        長(zhǎng)期性研究時(shí)間序列建立,或者進(jìn)行大數(shù)據(jù)綜合分析實(shí)際上更多依賴于田野的不定期重訪。在案例統(tǒng)計(jì)中,我們根據(jù)實(shí)際情況將其作為不定期重復(fù)部分(表1),但在討論中,我們單獨(dú)分開討論,目的是能夠?qū)⑵涮厥鈨r(jià)值體現(xiàn)出來。更多的綜合對(duì)比工作,借助于對(duì)很多研究樣地重訪后建立長(zhǎng)期年代序列(chronosequence),進(jìn)行對(duì)比分析[21, 40, 53, 56, 59, 60, 99]。Carilla和Grau[101]的研究比較特殊,他們采用第三方年代(樹輪)確定方法來研究草地演變,但其信息不確定性也較大。

        4 總結(jié)和展望

        通過上述對(duì)文獻(xiàn)報(bào)道的149個(gè)研究案例分析,我們確定長(zhǎng)期性退化草地生態(tài)恢復(fù)研究確實(shí)對(duì)科學(xué)研究和生態(tài)恢復(fù)實(shí)踐具有重要價(jià)值,受限于人力、物力的支持,且依賴于多方面,方法至關(guān)重要。因此,借助于案例重訪方法獲得可比較的長(zhǎng)期性數(shù)據(jù),以及在生態(tài)恢復(fù)中長(zhǎng)期性年代序列數(shù)據(jù)庫方法值得推薦和加強(qiáng),可以很好獲得長(zhǎng)期性研究結(jié)果?;謴?fù)方法與恢復(fù)年限之間沒有必然聯(lián)系,更取決于恢復(fù)方法的適宜性。特別注意,在我國(guó)采用植物種子種植恢復(fù)退化草地的工作,應(yīng)該注重更多的物種數(shù)混合種植技術(shù),而非我們當(dāng)前的僅采用幾種植物物種混合方法。當(dāng)前,我國(guó)已經(jīng)大范圍的開展了生態(tài)恢復(fù)研究工作,并且建立了各種研究基地,以便于開展綜合性,長(zhǎng)期性研究工作,特別需要能夠持續(xù)的研究設(shè)計(jì)和資助體系。因此,當(dāng)前的短期實(shí)地研究工作,盡可能的實(shí)現(xiàn)連續(xù)性的觀測(cè)研究,這樣為后來的長(zhǎng)期性研究能夠提供更多的數(shù)據(jù)參考。從學(xué)科范疇來講,恢復(fù)生態(tài)學(xué)更需要新的范式來引領(lǐng)理論和技術(shù)的發(fā)展[115-116]。

        [1] Squires V R, Lu X S, Lu Q, Wang T, Yang Y L. Rangeland Degradation and Recovery in China′s Pastoral Lands. London: CAB International, 2009.

        [2] Squires V R, Hua L M, Zhang D G, Li G L. Towards Sustainable Use of Rangelands in North-West China. Heidelberg, Germany: Springer, 2010.

        [3] Xu J T, Yin R S, Li Z, Liu C. China′s ecological rehabilitation: unprecedented efforts, dramatic impacts, and requisite policies. Ecological Economics, 2006, 57(4): 595- 607.

        [4] Han J G, Zhang Y J, Wang C J, Bai W M, Wang Y R, Han G D, Li L H. Rangeland degradation and restoration management in China. The Rangeland Journal, 2008, 30(2): 233- 239.

        [5] van Andel J, Aronson J. Restoration Ecology: The New Frontier. Malden, MA, Oxford: Blackwell Publishing, 2006.

        [6] Monaco T A, Jones T A, Thurow T L. Identifying rangeland restoration targets: an appraisal of challenges and opportunities. Rangeland Ecology & Management, 2012, 65(6): 599- 605.

        [7] Dong S K, Kassam K A S, Tourrand J F, Boone R B. Building Resilience of Human-Natural Systems of Pastoralism in the Developing World: Interdisciplinary Perspectives. Switzerland: Springer, 2016.

        [8] Hegedü?ová K, Senko D. Successional changes of dry grasslands in southwestern Slovakia after 46 years of abandonment. Plant Biosystems-An International Journal Dealing with all Aspects of Plant Biology, 2011, 145(3): 666- 687.

        [9] Weaver J E, Bruner W E. A seven-year quantitative study of succession in grassland. Ecological Monographs, 1945, 15(3): 297- 319.

        [10] White J W, Holben F J, Richer A C. Maintenance level of nitrogen and organic matter in grassland and cultivated soils over periods of 54 and 72 years. Journal of the American Society of Agronomy, 1945, 37: 21- 33.

        [11] Gardner J L. Effects of thirty years of protection from grazing in desert grassland. Ecology, 1950, 31(1): 44- 50.

        [12] Williams O B. Studies in the ecology of the riverine plain. V. Plant density response of species in aDanthoniaCaespitosagrassland to 16 years of grazing by merino sheep. Australian Journal of Botany, 1969, 17(2): 255- 268.

        [13] Willis K J, Araújo M B, Bennett K D, Figueroa-Rangel B, Froyd C A, Myers N. How can a knowledge of the past help to conserve the future? Biodiversity conservation and the relevance of long-term ecological studies. Philosophical Transactions of the Royal Society B: Biological Sciences, 2007, 362(1478): 175- 186.

        [14] Rull V, Vegas-Vilarrúbia T. What is long-term in ecology? Trends in Ecology & Evolution, 2011, 26(1): 3- 4.

        [15] Jackson S T. Integrating ecological dynamics across timescales: real-time, Q-time, and deep-time. PALAIOS, 2001, 16(1): 1- 2.

        [16] Li Y H, Wang W, Liu Z L, Jiang S. Grazing gradient versus restoration succession ofLeymuschinensis(Trin.) Tzvel. Grassland in Inner Mongolia. Restoration Ecology, 2008, 16(4): 572- 583.

        [17] Galvánek D, Lep? J. Changes of species richness pattern in mountain grasslands: abandonment versus restoration. Biodiversity and Conservation, 2008, 17(13): 3241- 3253.

        [18] Fritch R A, Sheridan H, Finn J A, Kirwan L, hUallacháin D. Methods of enhancing botanical diversity within field margins of intensively managed grassland: a 7-year field experiment. Journal of Applied Ecology, 2011, 48(3): 551- 560.

        [19] Seymour C L, Milton S J, Joseph G S, Dean W R J, Ditlhobolo T S, Cumming G S. Twenty years of rest returns grazing potential, but not palatable plant diversity, to Karoo rangeland, SOUTH Africa. Journal of Applied Ecology, 2010, 47(4): 859- 867.

        [21] Duprè C, Stevens C J, Ranke T, Bleeker A, Peppler-Lisbach C, Gowing D J G, Dise N B, Dorland E, Bobbink R, Diekmann M. Changes in species richness and composition in European acidic grasslands over the past 70 years: the contribution of cumulative atmospheric nitrogen deposition. Global Change Biology, 2010, 16(1): 344- 357.

        [22] Dormaar J F, Willms W D. Effect of forty-four years of grazing on fescue grassland soils. Journal of Range Management, 1998, 51(1): 122- 126.

        [23] Liu W G, Wei J, Cheng J M, Li W J. Profile distribution of soil inorganic carbon along a chronosequence of grassland restoration on a 22-year scale in the Chinese Loess plateau. Catena, 2014, 121: 321- 329.

        [24] Matějková I, van Diggelen R, Prach K. An attempt to restore a central European species-rich mountain grassland through grazing. Applied Vegetation Science, 2003, 6(2): 161- 168.

        [25] Lunt I D, Morgan J W. Vegetation changes after 10 years of grazing exclusion and intermittent burning in aThemedatriandra(Poaceae) grassland reserve in south-eastern Australia. Australian Journal of Botany, 1999, 47(4): 537- 552.

        [26] Wilson S D. Competition, resources, and vegetation during 10 years in native grassland. Ecology, 2007, 88(12): 2951- 2958.

        [27] Dzwonko Z, Loster S. A functional analysis of vegetation dynamics in abandoned and restored limestone grasslands. Journal of Vegetation Science, 2007, 18(2): 203- 212.

        [28] He N P, Wu L, Wang Y S, Han X G. Changes in carbon and nitrogen in soil particle-size fractions along a grassland restoration chronosequence in northern China. Geoderma, 2009, 150(3/4): 302- 308.

        [29] Brady W W, Stromberg M R, Aldon E F, Bonham C D, Henry S H. Response of a semidesert grassland to 16 years of rest from grazing. Journal of Range Management, 1989, 42(4): 284- 288.

        [30] Barbaro L, Dutoit T, Cozic P. A six-year experimental restoration of biodiversity by shrub-clearing and grazing in calcareous grasslands of the French Prealps. Biodiversity & Conservation, 2001, 10(1): 119- 135.

        [31] Hejcman M, Klaudisová M, Schellberg J, Honsová D. The Rengen grassland experiment: plant species composition after 64 years of fertilizer application. Agriculture, Ecosystems & Environment, 2007, 122(2): 259- 266.

        [32] Smith R S, Shiel R S, Bardgett R D, Millward D, Corkhill P, Evans P, Quirk H, Hobbs P J, Kometa S T. Long-term change in vegetation and soil microbial communities during the phased restoration of traditional meadow grassland. Journal of Applied Ecology, 2008, 45(2): 670- 679.

        [33] Baoyin T, Li F Y. Can shallow plowing and harrowing facilitate restoration ofLeymuschinensisgrassland? Results from a 24-year monitoring program. Rangeland Ecology & Management, 2009, 62(4): 314- 320.

        [34] Ruprecht E, Enyedi M Z, Szabó A, Fenesi A. Biomass removal by clipping and raking vs burning for the restoration of abandonedStipa-dominated European steppe-like grassland. Applied Vegetation Science, 2016, 19(1): 78- 88.

        [35] Hansson M, Fogelfors H. Management of a semi-natural grassland; results from a 15-year-old experiment in southern Sweden. Journal of Vegetation Science, 2000, 11: 31- 38.

        [36] Maccherini S, Santi E. Long-term experimental restoration in a calcareous grassland: identifying the most effective restoration strategies. Biological Conservation, 2012, 146(1): 123- 135.

        [37] Yuan J Y, Ouyang Z Y, Zheng H, Xu W H. Effects of different grassland restoration approaches on soil properties in the southeastern Horqin sandy land, northern China. Applied Soil Ecology, 2012, 61: 34- 39.

        [38] Schnoor T, Bruun H H, Olsson P A. Soil disturbance as a grassland restoration measure—effects on plant species composition and plant functional traits. PLoS One, 2015, 10(4): e0123698.

        [39] Menke S B, Gaulke E, Hamel A, Vachter N. The effects of restoration age and prescribed burns on grassland ant community structure. Environmental Entomology, 2015, 44(5): 1336- 1347.

        [40] Wang S K, Zuo X A, Zhao X Y, Li Y Q, Zhou X, Lv P, Luo Y Q, Yun J Y. Responses of soil fungal community to the sandy grassland restoration in Horqin sandy land, northern China. Environmental Monitoring and Assessment, 2016, 188(1): 21.

        [41] Billeter R, Peintinger M, Diemer M. Restoration of montane fen meadows by mowing remains possible after 4- 35 years of abandonment. Botanica Helvetica, 2007, 117(1): 1- 13.

        [42] Sammul M, Kauer K, K?ster T. Biomass accumulation during reed encroachment reduces efficiency of restoration of Baltic coastal grasslands. Applied Vegetation Science, 2012, 15(2): 219- 230.

        [43] Berg M, Joyce C, Burnside N. Differential responses of abandoned wet grassland plant communities to reinstated cutting management. Hydrobiologia, 2012, 692(1): 83- 97.

        [44] Gilhaus K, Vogt V, H?lzel N. Restoration of sand grasslands by topsoil removal and self-greening. Applied Vegetation Science, 2015, 18(4): 661- 673.

        [45] T?r?k P, Miglécz T, Valkó O, Kelemen A, Tóth K, Lengyel S, Tóthmérész B. Fast restoration of grassland vegetation by a combination of seed mixture sowing and low-diversity hay transfer. Ecological Engineering, 2012, 44: 133- 138.

        [46] T?r?k P, Vida E, Deák B, Lengyel S, Tóthmérész B. Grassland restoration on former croplands in Europe: an assessment of applicability of techniques and costs. Biodiversity and Conservation, 2011, 20(11): 2311- 2332.

        [47] Carter D L, Blair J M. High richness and dense seeding enhance grassland restoration establishment but have little effect on drought response. Ecological Applications, 2012, 22(4): 1308- 1319.

        [48] Zhang T, Sun Y, Shi Z Y, Feng G. Arbuscular mycorrhizal fungi can accelerate the restoration of degraded spring grassland in central Asia. Rangeland Ecology & Management, 2012, 65(4): 426- 432.

        [49] Pickett S T A, Kolasa J, Jones C G. Ecological Understanding: The Nature of Theory and the Theory of Nature. 2th ed. Amsterdam: Elsevier, 2007.

        [50] Kollmann J, Meyer S T, Bateman R, Conradi T, Gossner M M, de Souza Mendon?a M Jr, Fernandes G W, Hermann J M, Koch C, Müller S C, Oki Y, Overbeck G E, Paterno G B, Rosenfield M F, Toma T S P, Weisser W W. Integrating ecosystem functions into restoration ecology—recent advances and future directions. Restoration Ecology, 2016, 24(6): 722- 730.

        [51] Lengyel S, Varga K, Kosztyi B, Lontay L, Déri E, T?r?k P, Tóthmérész B. Grassland restoration to conserve landscape-level biodiversity: a synthesis of early results from a large-scale project. Applied Vegetation Science, 2012, 15(2): 264- 276.

        [52] James J J, Carrick P J. Toward quantitative dryland restoration models. Restoration Ecology, 2016, 24(S2): S85-S90.

        [53] Fensham R J, Butler D W, Fairfax R J, Quintin A R, Dwyer J M. Passive restoration of subtropical grassland after abandonment of cultivation. Journal of Applied Ecology, 2016, 53(1): 274- 283.

        [54] Coffin D P, Lauenroth W K, Burke I C. Recovery of vegetation in a semiarid grassland 53 years after disturbance. Ecological Applications, 1996, 6(2): 538- 555.

        [55] Wilsey B J, Martin L M. Top-down control of rare species abundances by native ungulates in a grassland restoration. Restoration Ecology, 2015, 23(4): 465- 472.

        [56] Ballantine K, Schneider R. Fifty-five years of soil development in restored freshwater depressional wetlands. Ecological Applications, 2009, 19(6): 1467- 1480.

        [57] Pywell R F, Meek W R, Webb N R, Putwain P D, Bullock J M. Long-term heathland restoration on former grassland: the results of a 17-year experiment. Biological Conservation, 2011, 144(5): 1602- 1609.

        [58] Bach E M, Baer S G, Meyer C K, Six J. Soil texture affects soil microbial and structural recovery during grassland restoration. Soil Biology and Biochemistry, 2010, 42(12): 2182- 2191.

        [59] Baer S G, Bach E M, Meyer C K, Du Preez C C, Six J. Belowground ecosystem recovery during grassland restoration: south African highveld compared to US tallgrass prairie. Ecosystems, 2015, 18(3): 390- 403.

        [60] Rosenzweig S T, Carson M A, Baer S G, Blair J M. Changes in soil properties, microbial biomass, and fluxes of C and N in soil following post-agricultural grassland restoration. Applied Soil Ecology, 2016, 100: 186- 194.

        [61] Woodcock B A, Bullock J M, Mortimer S R, Brereton T, Redhead J W, Thomas J A, Pywell R F. Identifying time lags in the restoration of grassland butterfly communities: a multi-site assessment. Biological Conservation, 2012, 155: 50- 58.

        [62] Schuch S, Bock J, Leuschner C, Schaefer M, Wesche K. Minor changes in orthopteran assemblages of central European protected dry grasslands during the last 40 years. Journal of Insect Conservation, 2011, 15(6): 811- 822.

        [63] Dong S K, Wen L, Li Y Y, Wang X X, Zhu L, Li X Y. Soil-quality effects of grassland degradation and restoration on the Qinghai-Tibetan plateau. Soil Science Society of America Journal, 2012, 76(6): 2256- 2264.

        [64] Oakley C A, Knox J S. Plant species richness increases resistance to invasion by non-resident plant species during grassland restoration. Applied Vegetation Science, 2013, 16(1): 21- 28.

        [65] Dong S K, Wang X X, Liu S L, Li Y Y, Su X K, Wen L, Zhu L. Reproductive responses of alpine plants to grassland degradation and artificial restoration in the Qinghai-Tibetan plateau. Grass and Forage Science, 2014, 70(2): 229- 238.

        [66] Murphy C A, Foster B L. Soil properties and spatial processes influence bacterial metacommunities within a grassland restoration experiment. Restoration Ecology, 2014, 22(5): 685- 691.

        [68] Wilson S D. Managing contingency in semiarid grassland restoration through repeated planting. Restoration Ecology, 2015, 23(4): 385- 392.

        [69] Auestad I, Austad I, Rydgren K. Nature will have its way: local vegetation trumps restoration treatments in semi-natural grassland. Applied Vegetation Science, 2015, 18(2): 190- 196.

        [70] Klimkowska A, van Diggelen R, Grootjans A P, Kotowski W. Prospects for fen meadow restoration on severely degraded fens. Perspectives in Plant Ecology, Evolution and Systematics, 2010, 12(3): 245- 255.

        [71] Wu X, Li Z S, Fu B J, Zhou W M, Liu H F, Liu G H. Restoration of ecosystem carbon and nitrogen storage and microbial biomass after grazing exclusion in semi-arid grasslands of Inner Mongolia. Ecological Engineering, 2014, 73: 395- 403.

        [72] Hald A B, Vinther E. Restoration of a species-rich fen-meadow after abandonment: response of 64 plant species to management. Applied Vegetation Science, 2000, 3(1): 15- 24.

        [73] Pyk?l? J. Cattle grazing increases plant species richness of most species trait groups in mesic semi-natural grasslands. Plant Ecology, 2005, 175(2): 217- 226.

        [74] Pyk?l? J, Luoto M, Heikkinen R K, Kontula T. Plant species richness and persistence of rare plants in abandoned semi-natural grasslands in northern Europe. Basic and Applied Ecology, 2005, 6(1): 25- 33.

        [75] Straskrabova J, Prach K. Five years of restoration of alluvial meadows: a case study from central Europe//Joyce C, Wade P, eds. European Wet Grasslands: Biodiversity, Management and Restoration. Chichester: John Wiley & Sons, 1998: 295- 303.

        [76] Kahmen S, Poschlod P, Schreiber K F. Conservation management of calcareous grasslands. Changes in plant species composition and response of functional traits during 25 years. Biological Conservation, 2002, 104(3): 319- 328.

        [77] Oelmann Y, Broll G, H?lzel N, Kleinebecker T, Vogel A, Schwartze P. Nutrient impoverishment and limitation of productivity after 20 years of conservation management in wet grasslands of north-western Germany. Biological Conservation, 2009, 142(12): 2941- 2948.

        [78] Galvánek D, Lep? J. How do management and restoration needs of mountain grasslands depend on moisture regime? Experimental study from north-western Slovakia (Western Carpathians). Applied Vegetation Science, 2009, 12(3): 273- 282.

        [79] Schrautzer J, Fichtner A, Huckauf A, Rasran L, Jensen K. Long-term population dynamics ofDactylorhizaincarnata(L.) Soo after abandonment and re-introduction of mowing. Flora—Morphology, Distribution, Functional Ecology of Plants, 2011, 206(7): 622- 630.

        [81] Niklaus P A, Wohlfender M, Siegwolf R, K?rner C. Effects of six years atmospheric CO2enrichment on plant, soil, and soil microbial C of a calcareous grassland. Plant and Soil, 2001, 233(2): 189- 202.

        [82] Sindh?j E, Hansson A C, Andrén O, K?tterer T, Marissink M, Pettersson R. Root dynamics in a semi-natural grassland in relation to atmospheric carbon dioxide enrichment, soil water and shoot biomass. Plant and Soil, 2000, 223(1/2): 255- 265.

        [83] Hejcman M, Klaudisová M,tursa J, PavlV, Schellberg J, Hejcmanová P, Hakl J, Rauch O, Vacek S. Revisiting a 37 years abandoned fertilizer experiment onNardusgrassland in the Czech Republic. Agriculture, Ecosystems & Environment, 2007, 118(1/4): 231- 236.

        [84] Maccherini S, Santi E, Marignani M. Detection of the effects of restoration on community composition in a calcareous grassland: does scale matter? Grassland Science, 2014, 60(1): 31- 35.

        [85] Metsoja J A, Neuenkamp L, Pihu S, Vellak K, Kalwij J M, Zobel M. Restoration of flooded meadows in Estonia—vegetation changes and management indicators. Applied Vegetation Science, 2012, 15(2): 231- 244.

        [86] Sindh?j E, Andrén O, K?tterer T, Marissink M, Pettersson R. Root biomass dynamics in a semi-natural grassland exposed to elevated atmospheric CO2for five years. Acta Agriculturae Scandinavica, Section B-Soil & Plant Science, 2004, 54(2): 50- 59.

        [87] Halpern C B, Haugo R D, Antos J A, Kaas S S, Kilanowski A L. Grassland restoration with and without fire: evidence from a tree-removal experiment. Ecological Applications, 2012, 22(2): 425- 441.

        [88] Hall S L, McCulley R L, Barney R J. Restoration of native warm season grassland species in a tall fescue pasture using prescribed fire and herbicides. Restoration Ecology, 2012, 20(2): 194- 201.

        [89] Halpern C B, Antos J A, Beckman L M. Vegetation recovery in slash-pile scars following conifer removal in a grassland-restoration experiment. Restoration Ecology, 2014, 22(6): 731- 740.

        [90] Munson S M, Lauenroth W K. Plant community recovery following restoration in semiarid grasslands. Restoration Ecology, 2012, 20(5): 656- 663.

        [91] 董世魁, 蒲小鵬, 胡自治. 青藏高原高寒人工草地生產(chǎn)-生態(tài)范式. 北京: 科學(xué)出版社, 2013

        [92] 尚占環(huán). 青藏高原三江源區(qū)“黑土灘”二次發(fā)生的地下過程及其內(nèi)部驅(qū)動(dòng)機(jī)制研究(結(jié)題報(bào)告). 北京: 國(guó)家自然科學(xué)基金委, 2016.

        [93] Rychnovská M, Bla?ková D, Hrabé F. Conservation and development of floristically diverse grasslands in central Europe. In:′t Mannetje L, Frame J, eds. Grassland and Society. Wageningen: Wageningen Pers, 1994: 266- 277.

        [94] Malmstrom C M, Butterfield H S, Barber C, Dieter B, Harrison R, Qi J Q, Riao D, Schrotenboer A, Stone S, Stoner C J, Wirka J. Using remote sensing to evaluate the influence of grassland restoration activities on ecosystem forage provisioning services. Restoration Ecology, 2009, 17(4): 526- 538.

        [95] Foster B L, Kindscher K, Houseman G R, Murphy C A. Effects of hay management and native species sowing on grassland community structure, biomass, and restoration. Ecological Applications, 2009, 19(7): 1884- 1896.

        [96] Hájková P, Hájek M, Kintrová K. How can we effectively restore species richness and natural composition of aMolinia-invaded fen? Journal of Applied Ecology, 2009, 46(2): 417- 425.

        [97] Kinucan R J, Smeins F E. Soil seed bank of a semiarid Texas grassland under three long-term (36- years) grazing regimes. The American Midland Naturalist, 1992, 128(1): 11- 21.

        [98] Xie Z B, Cadisch G, Edwards G, Baggs E M, Blum H. Carbon dynamics in a temperate grassland soil after 9 years exposure to elevated CO2(Swiss FACE). Soil Biology and Biochemistry, 2005, 37(7): 1387- 1395.

        [99] Breuer L, Huisman J A, Keller T, Frede H G. Impact of a conversion from cropland to grassland on C and N storage and related soil properties: analysis of a 60-year chronosequence. Geoderma, 2006, 133(1/2): 6- 18.

        [100] Feng Y, Lu Q, Tokola T, Liu H, Wang X. Assessment of grassland degradation in Guinan county, Qinghai Province, China, in the past 30 years. Land Degradation & Development, 2009, 20(1): 55- 68.

        [101] Carilla J, Grau H R. 150 years of tree establishment, land use and climate change in Montane grasslands, Northwest Argentina. Biotropica, 2010, 42(1): 49- 58.

        [102] Kinyua D, McGeoch L E, Georgiadis N, Young T P. Short-term and long-term effects of soil ripping, seeding, and fertilization on the restoration of a Tropical rangeland. Restoration Ecology, 2010, 18(S1): 226- 233.

        [103] De Deyn G B, Shiel R S, Ostle N J, McNamara N P, Oakley S, Young I, Freeman C, Fenner N, Quirk H, Bardgett R D. Additional carbon sequestration benefits of grassland diversity restoration. Journal of Applied Ecology, 2011, 48(3): 600- 608.

        [104] Andrade B O, Overbeck G E, Pilger G E, Hermann J M, Conradi T, Boldrini I I, Kollmann J. Intraspecific trait variation and allocation strategies of calcareous grassland species: results from a restoration experiment. Basic and Applied Ecology, 2014, 15(7): 590- 598.

        [105] Miao R H, Jiang D M, Musa A, Zhou Q L, Guo M X, Wang Y C. Effectiveness of shrub planting and grazing exclusion on degraded sandy grassland restoration in Horqin sandy land in Inner Mongolia. Ecological Engineering, 2015, 74: 164- 173.

        [106] Jacquemyn H, van Mechelen C, Brys R, Honnay O. Management effects on the vegetation and soil seed bank of calcareous grasslands: an 11-year experiment. Biological Conservation, 2011, 144(1): 416- 422.

        [108] Bakker J D, Wilson S D, Christian J M, Li X D, Ambrose L G, Waddington J. Contingency of grassland restoration on year, site, and competition from introduced grasses. Ecological Applications, 2003, 13(1): 137- 153.

        [109] 朱桂林, 山侖, 劉國(guó)彬. 棄耕演替與恢復(fù)生態(tài)學(xué). 生態(tài)學(xué)雜志, 2004, 23(6): 94- 96.

        [110] Watson C J, Matthews D I. A 10-year study of phosphorus balances and the impact of grazed grassland on total P redistribution within the soil profile. European Journal of Soil Science, 2008, 59(6): 1171- 1176.

        [111] Van Eekeren N, Bommelé L, Bloem J, Schouten T, Rutgers M, de Goede R, Reheul D, Brussaard L. Soil biological quality after 36 years of ley-arable cropping, permanent grassland and permanent arable cropping. Applied Soil Ecology, 2008, 40(3): 432- 446.

        [112] Kueffer C, Niinemets ü, Drenovsky P E, Kattge J, Milberg P, Poorter H, Reich P B, Werner C, Westoby M, Wright I J. Fame, glory and neglect in meta-analyses. Trends in Ecology & Evolution, 2011, 26(10): 493- 494.

        [113] Koricheva J, Gurevitch J. Uses and misuses of meta-analysis in plant ecology. Journal of Ecology, 2014, 102(4): 828- 844.

        [114] Fraser L H, Henry H A, Carlyle C N, White S R, Beierkuhnlein C, Cahill J F Jr, Casper B B, Cleland E, Collins S L, Dukes J S, Kanapp A K, Lind E, Long R J, Luo Y Q, Reich P B, Smith M D, Sternberg M, Turkington R. Coordinated distributed experiments: an emerging tool for testing global hypotheses in ecology and environmental science. Frontiers in Ecology and the Environment, 2013, 11(3): 147- 155.

        [115] Choi Y D. Restoration ecology to the future: a call for new paradigm. Restoration Ecology, 2007, 15(2): 351- 353.

        [116] 張琨, 呂一河, 傅伯杰. 生態(tài)恢復(fù)中生態(tài)系統(tǒng)服務(wù)的演變: 趨勢(shì)、過程與評(píng)估. 生態(tài)學(xué)報(bào), 2016, 36(20): 6337- 6344.

        猜你喜歡
        長(zhǎng)期性年限草地
        正畸聯(lián)合口腔修復(fù)治療長(zhǎng)期性缺牙的臨床效果評(píng)價(jià)
        影響種公牛使用年限的幾個(gè)因素與解決辦法
        草地上的事
        幼兒100(2020年31期)2020-11-18 03:42:00
        草地
        不同產(chǎn)地、生長(zhǎng)年限銀杏葉總多酚含量比較
        中成藥(2017年6期)2017-06-13 07:30:35
        草地上
        福建長(zhǎng)汀縣生態(tài)恢復(fù)的艱巨性和長(zhǎng)期性
        施以規(guī)矩,始成方圓
        體外發(fā)酵法評(píng)定不同茬次和生長(zhǎng)年限苜蓿的營(yíng)養(yǎng)價(jià)值
        你準(zhǔn)備好了嗎?
        日韩熟女精品一区二区三区视频| 久久无码av三级| 99视频全部免费精品全部四虎| 青青草久热手机在线视频观看 | 日本不卡一区二区三区在线视频| 乱色精品无码一区二区国产盗| 综合三区后入内射国产馆| 日韩中文字幕网站| 亚洲本色精品一区二区久久| 欧美精品国产综合久久| 成年女人毛片免费观看97| 国产对白刺激在线观看| 国产色av一区二区三区| 亚洲欧美一区二区成人片| 欧美极品美女| 内谢少妇xxxxx8老少交 | 久草手机视频在线观看| 一二三四日本中文在线| 国模私拍福利一区二区| 一本久道久久综合狠狠操| 中国老熟女露脸老女人| 男男啪啪激烈高潮cc漫画免费 | 国产成人精品蜜芽视频| 青青草成人免费在线视频| 亚洲av无码一区二区三区人| 国产成人av免费观看| 九九在线精品视频xxx| 天堂久久一区二区三区| 18禁黄网站禁片免费观看女女| 亚洲妓女综合网99| 女优免费中文字幕在线| 国产91清纯白嫩初高中在线观看| 麻豆国产原创视频在线播放| 久久成人永久免费播放| 亚洲啪啪色婷婷一区二区| 久久天天躁狠狠躁夜夜不卡| 911精品国产91久久久久| 国产精品农村妇女一区二区三区| 四虎永久在线精品免费网址| 亚洲美免无码中文字幕在线| 国产免费午夜福利蜜芽无码|