苔蘚植物是森林生態(tài)系統(tǒng)中生物多樣性的重要組成部分,，對森林的演替過程與功能起著重要的作用,。由于苔蘚植物具有單層細(xì)胞的特征，對微氣候和微生境的依賴很強(qiáng),，因此苔蘚植物對更新策略引起的微環(huán)境和微生境變化很敏感,，常常被用作評估更新策略導(dǎo)致環(huán)境變化的指示植物。
自然更新形成闊葉林和人工營造針葉林是世界各地對采伐地更新采用的最常見的兩種方式,。自然更新和造林導(dǎo)致了不同的樹種組成,，可能會影響林下植物的多樣性。一些研究認(rèn)為自然更新策略是保護(hù)苔蘚植物多樣性的有效途徑,，人工造林會造成一些敏感苔蘚物種消失,。也有研究表明在一定程度上而言，人工造林也是保護(hù)地表苔蘚植物多樣性的一種有效途徑,。中國作為世界上人工林面積大國之一,，為了保護(hù)國家的生態(tài)安全較多的采用人工更新策略,，一直不斷的在造林，人工林面積不斷增大,，其中針葉林面積已經(jīng)占據(jù)人工林面積的71%。因此了解不同更新策略對地表苔蘚植物多樣性的影響效應(yīng)對于完善林業(yè)實踐措施,、促進(jìn)現(xiàn)代林業(yè)可持續(xù)發(fā)展與生物多樣性的保護(hù)具有重要的作用,。
中科院成都生物研究所恢復(fù)生態(tài)學(xué)學(xué)科組包維楷團(tuán)隊閆曉麗博士等選擇川西亞高山地區(qū)皆伐跡地上相同立地條件、相同林齡的云杉人工林和自然更新的樺木林樣地各13塊,，采用傳統(tǒng)群落學(xué)調(diào)查方法,，開展了林下地表苔蘚植物多樣性調(diào)查。其結(jié)果表明：自然更新林比人工林具有較低的樣地密度,、喬木蓋度和高度,，較高的草本高度、灌木蓋度和地表苔蘚多樣性指數(shù),。自然更新林比人工林具有較多的地表苔蘚物種豐富度（205 vs 157）,，傾向于分布在自然林下的物種數(shù)量要遠(yuǎn)大于傾向于分布在人工林下的物種(116 vs 48)。種組分析表明次生林下具有較多的側(cè)蒴蘚類物種和三種生長性物種（扇型,、平鋪型,、草狀）的豐富度。與更新策略相關(guān)的林分結(jié)構(gòu)的差異是影響地表苔蘚物種組成和多樣性變化的重要因素,。綜合分析表明，人工更新策略與自然更新策略對林下地表苔蘚物種組成與多樣性產(chǎn)生了不同的影響,，自然更新策略較人工更新策略能更有效地恢復(fù)林下地表苔蘚物種組成與多樣性,。
該研究成果發(fā)表于Annals of Forest Science， 該研究得到國家自然科學(xué)基金的資助（生物谷Bioon.com）,。
生物谷推薦的英文摘要
Annals of Forest Science DOI：10.1007/s13595-013-0323-7
Regeneration strategies influence ground bryophyte composition and diversity after forest clearcutting
Xiao Li Yan,， Wei Kai Bao， Xue Yong Pang,， Ning Xuan Zhang,， Jiquan Chen
Context
Natural regeneration with broadleaved species and reforestation with coniferous trees are two widely practiced forest regeneration strategies after timber harvesting. They lead to different tree species composition and may cause different understory biodiversity， but the effects on ground bryophyte composition and diversity are not well-known.
Aims
We tested whether natural regeneration with broadleaved species and reforestation with spruce induced different diversities of the ground bryophyte populations 20–40 years after old-growth spruce forest clearcutting in the subalpine regions of southwestern China.
Methods
Differences between natural stands and plantations were compared through the analysis of 13 paired stands,， with 78 plots,， 390 shrub/herb quadrats， and a total of 1,，560 bryophyte quadrats.
Results
Naturally regenerated forests were characterized by lower density and cover and lower tree height but higher herbaceous plant height,， shrub cover， and bryophyte diversity. They also harbored many more ground bryophytes. The species richness of pleurocarpous mosses and fans,， mats,， and turfs were significantly higher in naturally regenerated forests. Frequency difference analysis demonstrated that more bryophyte species preferred ground habitats in naturally regenerated forests than in plantations (116 vs. 48 species). The canonical correspondence analysis indicated that stand structure attributes were more important determinants of ground bryophyte diversity and abundance.
Conclusion
Natural regeneration and reforestation resulted in large differences in ground bryophyte populations. A larger diversity was observed in the former case,， and natural regeneration practices can be an effective measure for the protection of ground bryophyte diversity after clearcutting.
