Pizzeghello D, Zanella A, Carletti P, Nardi S
Dipartimento di Biotecnologie Agrarie, Università di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, Padova, Italy.
Chemosphere. 2006 Oct;65(2):190-200. doi: 10.1016/j.chemosphere.2006.03.001. Epub 2006 Apr 18.
Despite a growing attention to the dissolved organic matter (DOM) in terrestrial ecosystems and evidence of the fact that vegetation affects the quality of both undissolved and dissolved organic matter in soil, the role of DOM as a biological indicator is still poorly understood. In this work, the fertility of 59 sites, divided into eight key alliances of the order Fagetalia sylvaticae Pawl., was studied considering chemical and biological parameters such as soil DOM, hormone-like activity, low-molecular-weight (LMW) aliphatic and phenolic acids, and floristic data. Both non-parametric tests and principal component analysis (PCA) revealed differences between silver fir and beech forests and within each type of forest. There were also differences between neutrophilous and acidophilous types. What's more, PCA reveals the dominance of the auxin (IAA)-like activity, and of some phenolic acids in distinguishing the acidophilous beeches (ACI) form the other types, whereas the gibberellin (GA)-like activity is more relevant in neutrophilous conditions such as thermophilous (THE) and mesophilous (MESO) beeches and montane (MO), high montane (HMA), high montane (HMC) silver fir forests. The GA-like activity is also related to the succinic, fumaric, malonic, and l-malic acids in the MO, HMA and HMC silver fir forests. Moreover, the role of LMW aliphatic acids in mobilizing the hormone-like activity, which improves forest growth, is stressed. The growth of seedlings of Picea abies was influenced by the phenolic acid content. At concentrations between 1 and 100 microM, phenylacetic and protocatechuic acids inhibited root growth to the same extent as indoleacetic acid, while p-hydroxybenzoic acid had a stimulating effect comparable to that of gibberellic acid. The aliphatic and phenolic acids appear to be related to plant strategies that influence soil fertility affecting plant growth through rhizodeposition. The role of LMW aliphatic and phenolic acids as molecular markers of ecosystem function is noted.
尽管陆地生态系统中溶解有机 matter (DOM) 受到越来越多的关注，且有证据表明植被会影响土壤中未溶解和溶解有机 matter 的质量，但 DOM 作为生物指标的作用仍知之甚少。在这项研究中，考虑了土壤 DOM、激素样活性、低分子量 (LMW) 脂肪族和酚酸以及植物区系数据等化学和生物学参数，对 59 个地点（分为山毛榉林纲的八个关键联盟）的肥力进行了研究。非参数检验和主成分分析 (PCA) 均揭示了冷杉林和山毛榉林之间以及每种森林类型内部的差异。嗜中性和嗜酸类型之间也存在差异。此外，PCA 显示生长素 (IAA) 样活性以及某些酚酸在区分嗜酸山毛榉 (ACI) 与其他类型时占主导地位，而赤霉素 (GA) 样活性在嗜中性条件下（如嗜热 (THE) 和中生 (MESO) 山毛榉以及山地 (MO)、高山区 (HMA)、高山区 (HMC) 冷杉林）更为重要。GA 样活性还与 MO、HMA 和 HMC 冷杉林中的琥珀酸、富马酸、丙二酸和 L - 苹果酸有关。此外，强调了 LMW 脂肪族酸在调动激素样活性以促进森林生长方面的作用。欧洲云杉幼苗的生长受酚酸含量影响。在 1 至 100 microM 的浓度范围内，苯乙酸和原儿茶酸对根系生长的抑制程度与吲哚乙酸相同，而对羟基苯甲酸具有与赤霉素相当的刺激作用。脂肪族和酚酸似乎与通过根际沉积影响土壤肥力从而影响植物生长的植物策略有关。注意到 LMW 脂肪族和酚酸作为生态系统功能分子标记的作用。
