由于技術(shù)手段的限制,，傳統(tǒng)上人們往往認(rèn)為微生物的地理分布與大型動(dòng)植物的分布有著根本區(qū)別,，即微生物是全球性隨機(jī)分布的,。隨著分子生物學(xué)技術(shù)在微生物生態(tài)學(xué)研究中的應(yīng)用，近年來(lái)發(fā)現(xiàn)土壤微生物群落結(jié)構(gòu)和多樣性同樣具有一定的地理分布格局,，顛覆了人們傳統(tǒng)上對(duì)于微生物全球性隨機(jī)分布的認(rèn)識(shí),。這些研究證明了微生物的分布在空間上是非隨機(jī)的，卻仍沒(méi)有回答微生物的這種非隨機(jī)分布是如何產(chǎn)生和維持的,，即哪些因子驅(qū)動(dòng)了微生物多樣性的空間分布特征,。
近日，中科院生態(tài)環(huán)境研究中心賀紀(jì)正課題組有關(guān)大尺度下土壤微生物多樣性變化驅(qū)動(dòng)機(jī)制的研究取得重要成果,，論文發(fā)表于Nature系列雜志《國(guó)際微生物生態(tài)學(xué)會(huì)會(huì)刊》（The ISME Journal）上（Differences in soil bacterial diversity: driven by contemporary disturbances or historical contingencies? The ISME Journal (2008) 2, 254–264）,。
他們采用分子生物學(xué)技術(shù)，結(jié)合先進(jìn)的統(tǒng)計(jì)分析方法,，對(duì)大量土壤樣品細(xì)菌多樣性特征進(jìn)行了系統(tǒng)分析,，發(fā)現(xiàn)歷史進(jìn)化（以地理上分隔的不同取樣點(diǎn)或土壤類型、土壤剖面層次來(lái)表征）是驅(qū)動(dòng)大尺度下（約1000公里）土壤細(xì)菌多樣性變化的主控因子,，其對(duì)土壤細(xì)菌多樣性變化的貢獻(xiàn)約為60%,；當(dāng)代環(huán)境擾動(dòng)（以不同的取樣時(shí)間和施肥處理來(lái)表征）也可造成局部土壤細(xì)菌多樣性變化，其對(duì)土壤細(xì)菌多樣性變化的貢獻(xiàn)約為20%,；另有約20%的貢獻(xiàn)來(lái)自于該研究尚未考察到的因子,。這一研究首次在大尺度下對(duì)土壤細(xì)菌多樣性的變化給出了定量表征,，并為開(kāi)展類似的土壤微生物生物地理學(xué)研究提供了方法思路。該項(xiàng)研究成果表明,，歷史進(jìn)化和現(xiàn)代環(huán)境擾動(dòng)對(duì)土壤細(xì)菌多樣性變化的作用模式與大型動(dòng)植物有相似之處,，可能有一些對(duì)所有類型生物都適用的生物地理分布規(guī)律存在。
賀紀(jì)正研究員為中國(guó)科學(xué)院“引進(jìn)國(guó)外杰出人才”計(jì)劃入選者,，2005年到生態(tài)環(huán)境研究中心組建“土壤分子生態(tài)學(xué)”課題組,。該項(xiàng)研究受到科技部“973計(jì)劃”、國(guó)家自然科學(xué)基金和科學(xué)院知識(shí)創(chuàng)新方向性項(xiàng)目的支持,。（來(lái)源：中科院生態(tài)環(huán)境研究中心）
生物谷推薦原始出處：
（The ISME Journal）,，(2008) 2, 254–264，Yuan Ge,，Ji-zheng He
Differences in soil bacterial diversity: driven by contemporary disturbances or historical contingencies?
Yuan Ge1,2, Ji-zheng He1, Yong-guan Zhu1, Jia-bao Zhang3, Zhihong Xu4, Li-mei Zhang1 and Yuan-ming Zheng1
Abstract
Contemporary environmental disturbances and historical contingencies are considered to be major factors driving current differences in microbial diversity. However, little was known about their relative importance. This study combines culture-independent molecular techniques and advanced statistical analyses to examine quantitatively the relative importance of contemporary disturbances and historical contingencies in influencing large-scale soil bacterial diversity using a large set of manipulated field-based molecular data (212 samples). Contemporary disturbances were represented by applications of different fertilizers N, P, K and organic manure (OM) and historical contingencies by distinct geographic sampling locations and soil profiles. Multivariate regression tree (MRT) analysis showed that diversity estimates were mainly distinguished by sampling locations, which explained 40.8% of the variation in bacterial diversity, followed by soil profiles (19.5%), sampling time (13.1%), OM (3.7%) and P (1.8%). Aggregated boosted tree (ABT) analysis showed that the relative importance of different categorical factors on soil bacterial diversity variation was ranked as sampling locations, soil profiles, sampling time, OM and P. Both MRT and ABT analyses showed that historical contingencies were the dominant factor driving variation in bacterial diversity across a regional scale (about 1000 km), whereas some contemporary disturbances also caused variation in bacterial diversity at a local scale. This study demonstrated that past events and contemporary disturbances had similar influence on soil bacterial diversity to that documented for macroorganisms, indicating that there might be some common aspects of biogeography to all organisms.
