The effects of activated carbon and plants diversity ... - 华南农业大学

华 南 农 业 大 学 农 学 院 第 三 届 综 述 大 赛 获 奖 作 品 论 文 集一 等 奖 作 品produce a diverse chemical mixture, which in turn will reduce (dilution) allelopathy for eachspeices and the autotoxicity of autoxic species (Mazzoleni et al. 2007). Then, despite theunavoidable detrimental effect at the individual scale, the negative feedback can generate apositive effect at the community level, thus sustaining the maintenance of speces diversitythat overcomes the cost of a higher interspecific competition for resources (Bonanomi et al.2005).4. The effects of activated carbon on plants allelopathy in ecology experimentalstudyRecently, activated carbon (AC) is widely used as a technique for neutralizing allelopathiccompounds (Al Hamdi 2001; Callaway and Aschehoug 2000b; Prati and Bossdorf 2004),which has been used to examine allelopathic effects by removing or immobilizingallelochemicals in the soil (Callaway and Aschehoug 2000a; b; Inderjit and Nilsen 2003;Kulmatiski and Beard 2006; Mahall and Callaway 1992; Nilsson 1994). AC has large surfacearea and pore volume and acts as an adsorbent for many organic compounds (Cheremisinoffand Morresi 1978) in intra- and inter-specific plant competition in ecological studies (Mahalland Callaway 1992).Compromise in competitive superiority of a plant after AC addition in soil6indicates theinvolvement of allelopathic effects. Unfortunately, contrary to former studies, a few studiesdemonstrated that, by adsorbing chemical compounds, AC may also have negative effects onplant growth and symbiosis with mycorrhizal fungi(Wurst et al. 2010). Lau (2008) alsofound that AC may affect nitrogen and nutrient availability and concentrations in soil, and mayinfluence plant species differently. As far it is not clear that the positive or negative effects ofAC on plants are caused by application methods, materials or receptor species used. Toinvestigate whether AC addition can compromise the autotoxicity conditions of alfalfa, ACwas applied to the sand growth media.Recently, most research using AC has focused on the ability of AC to sequesterallelochemicals (Callaway and Aschehoug 2000a; Lau et al. 2008); and AC on competitiveadvantage of a plant is considered as a proof for the involvement of allelopathic compounds.There were findings support the studies that have found the addition of AC had a beneficialeffect on plants, in order to improve the autotoxicity conditions. AC effects on plant growthmight be due to a complex combination of its direct effects on heterotrophic, symbiotic, andpathogenic soil organisms as well as its ability to sequester allelochemicals. There is researchsuggests that AC plus seed treatment did restore native plant dominance (Kulmatiski 2010),however, there were studies report that if the specie does not control for confounding effects ofAC on both test and focal species growth, or the use of AC to test for allelopathy may lead to