滇池大型水生植物研究进展

从大型水生植物的组成及演替、生理生态学、水环境净化能力,以及流域水生外来入侵植物研究和大型水生植被恢复研究等方面对滇池大型水生植物的研究进展进行了综述。结果显示从20世纪50年代至今,滇池水生植被大量减少、水生植物多样性下降,外来物种影响增加,耐污物种占优势;另一方面,近年来随着滇池水环境的综合治理,部分水质好转地段沉水植物种类有所增加。建议加强滇池水生高等植物的生理生态学研究及滇池外来水生植物引种的生态安全评价工作。

植物群落演替过程中植物生理生态学特性及其主要环境因子的变化

对 2 0世纪 80年代以来有关植物群落演替的生理生态学机制研究的主要结果进行了综述。演替早期和演替后期各种植物所处环境常有很大差别。演替早期的生境具有开放性和光照充足等特点 ,各环境因子富于变化 ;演替后期的生境由于植被的缓冲作用 ,一般较为封闭和稳定 ,各环境因子在空间尺度上的异质性较强。演替早期和演替后期群落不仅物种组成不同 ,而且在演替不同阶段中出现的物种的生理生态特性以及对环境的适应性也有很大差别 ,这些物种的生理生态差异使得物种更替现象经常发生 ,也使得演替能够顺利进行。在全球气候变化影响下 ,生态系统将会出现更多的次生演替和长时间停留于演替早期阶段的情况。

Assessment of organic compost and biochar in promoting phytoremediation of crude-oil contaminated soil using Calendula officinalis in the Loess Plateau, China

The Loess Plateau,located in Gansu Province,is an important energy base in China because most of the oil and gas resources are distributed in Gansu Province.In the last 40 a,ecological environment in this region has been extremely destroyed due to the over-exploitation of crude-oil resources.Remediation of crude-oil contaminated soil in this area remains to be a challenging task.In this study,in order to elucidate the effects of organic compost and biochar on phytoremediation of crude-oil contaminated soil(20 g/kg)by Calendula officinalis,we designed five treatments,i.e.,natural attenuation(CK),planted C.officinalis only(P),planted C.officinalis with biochar amendment(PB),planted C.officinalis with organic compost amendment(PC),and planted C.officinalis with co-amendment of biochar and organic compost(PBC).After 152 d of cultivation,total petroleum hydrocarbons(TPH)removal rates of CK,P,PB,PC and PBC were 6.36%,50.08%,39.58%,73.10%and 59.87%,respectively.Shoot and root dry weights of C.officinalis significantly increased by 172.31%and 80.96%under PC and 311.61%and 145.43%under PBC,respectively as compared with P(P<0.05).Total chlorophyll contents in leaves of C.officinalis under P,PC and PBC significantly increased by 77.36%,125.50%and 79.80%,respectively(P<0.05)as compared with PB.Physical-chemical characteristics and enzymatic activity of soil in different treatments were also assessed.The highest total N,total P,available N,available P and SOM(soil organic matter)occurred in PC,followed by PBC(P<0.05).C.officinalis rhizospheric soil dehydrogenase(DHA)and polyphenol oxidase(PPO)activities in PB were lower than those of other treatments(P<0.05).The values of ACE(abundance-based coverage estimators)and Chao 1 indices for rhizospheric bacteria were the highest under PC followed by PBC,P,PB and CK(P<0.05).However,the Shannon index for bacteria was the highest under PC and PBC,followed by P,PB and CK(P<0.05).In terms of soil microbial community composition,Proteiniphilum,Immundisolibacteraceae and Solimonadaceae were relatively more abundant under PC and PBC.Relative abundances of Pseudallescheria,Ochroconis,Fusarium,Sarocladium,Podospora,Apodus,Pyrenochaetopsis and Schizothecium under PC and PBC were higher,while relative abundances of Gliomastix,Aspergillus and Alternaria were lower under PC and PBC.As per the nonmetric multidimensional scaling(NMDS)analysis,application of organic compost significantly promoted soil N and P contents,shoot length,root vitality,chlorophyll ratio,total chlorophyll,abundance and diversity of rhizospheric soil microbial community in C.officinalis.A high p H value and lower soil N and P contents induced by biochar,altered C.officinalis rhizospheric soil microbial community composition,which might have restrained its phytoremediation efficiency.The results suggest that organic compost-assisted C.officinalis phytoremediation for crude-oil contaminated soil was highly effective in the Loess Plateau,China.