Department of Environmental and Plant Parasitology, Parasitological Institute of Slovak Academy of Science, Košice, Slovak Republic.
Department of Environmental and Plant Parasitology, Parasitological Institute of Slovak Academy of Science, Košice, Slovak Republic.
Sci Total Environ. 2017 Aug 15;592:106-114. doi: 10.1016/j.scitotenv.2017.02.238. Epub 2017 Mar 15.
Better understanding of interactions among belowground and aboveground components in biotopes may improve our knowledge about soil ecosystem, and is necessary in environment assessment using indigenous soil organisms. In this study, we proposed that in disturbed biotopes, vegetation play important role in the buffering of contamination impact on soil communities and decrease the ecological pressure on soil biota. To assess the effects of these interactions we compared nematode communities, known for their bioindication abilities, from four types of disturbed and undisturbed biotopes (coniferous forest, permanent grassland, agricultural field, clearings), where the main stress agent was represented by long-term acidic industrial emissions containing heavy metals (As, Cd, Cu, and Pb). To understand the ecological interactions taking place in studied biotopes, we studied abiotic factors (soil properties) and biotic factors (vegetation, nematode communities). Except significant increase in metals total and mobile concentrations in disturbed biotopes soil, we found acidification of soil horizon, mainly in the clearings (pH=3.68), due to SO precipitation. These factors has caused in clearings degradation of native phytocoenoses and decrease in decomposition rate characterized by high amount of organic matter (C=4.29%). Nematodes reacts to these conditions by shifts in trophic structure (bacteriovores to fungal feeders), increase in c-p 2 genera (Aphelenchoides, Acrobeloides, and Cephalobus), absence of sensitive groups (c-p 3-5, omnivores, predators), and decrease in ecological indices (SI, MI, MI2-5, H'). Similar contamination was found in forest biotope, but the nematodes composition indicates more suitable conditions; more complex community structure (presence of sensitive trophic and higher c-p groups), higher abundance and indices values, comparable with less stressed field and grassland biotopes. As showed our results, the vegetation undoubtedly plays an important role not only as a resource of services indispensable for the ecosystem, but also as a significant buffer of negative impacts acting within.
更好地理解生物区地下和地上成分之间的相互作用可以提高我们对土壤生态系统的认识，并且在使用本土土壤生物进行环境评估时是必要的。在这项研究中，我们提出，在受干扰的生物区，植被在缓冲污染对土壤群落的影响以及降低土壤生物区的生态压力方面发挥着重要作用。为了评估这些相互作用的影响，我们比较了来自四种受干扰和未受干扰生物区（针叶林、永久性草地、农田、空地）的线虫群落，这些生物区的主要压力因素是长期含有重金属（砷、镉、铜和铅）的酸性工业排放物。为了了解在研究生物区发生的生态相互作用，我们研究了非生物因素（土壤特性）和生物因素（植被、线虫群落）。除了受干扰生物区土壤中金属总量和可移动浓度的显著增加外，我们还发现由于 SO 沉淀，土壤剖面酸化，主要发生在空地（pH=3.68）。这些因素导致了原生植物群落的退化和分解率的降低，这表现为大量的有机物（C=4.29%）。线虫通过营养结构的转变（细菌食者转变为真菌食者）、c-p 2 属（Aphelenchoides、Acrobeloides 和 Cephalobus）的增加、敏感类群（c-p 3-5、杂食者、捕食者）的缺失以及生态指数（SI、MI、MI2-5、H'）的降低来应对这些条件。在森林生物区也发现了类似的污染，但线虫的组成表明了更适宜的条件；更复杂的群落结构（存在敏感的营养类群和更高的 c-p 类群）、更高的丰度和指数值，与受干扰较小的农田和草地生物区相当。正如我们的结果所示，植被无疑不仅作为生态系统不可缺少的服务资源发挥着重要作用，而且还作为一个重要的缓冲区，缓冲了生态系统内的负面影响。
