Panayiotou Evaggelia, Dimou Maria, Monokrousos Nikolaos
Department of Biological Applications and Technology, University of Ioannina, 45110, Ioannina, Greece.
Department of Ecology, School of Biology, Aristotle University, 54124, Thessaloniki, Greece.
Environ Monit Assess. 2017 Aug 8;189(9):441. doi: 10.1007/s10661-017-6161-6.
We investigated the temporal and among-site differentiation of soil functionality properties in fields under different grazing intensities (heavy and light) and compared them to those found in their adjacent hedgerows, consisting either of wooden shrubs (Rubus canescens) or of high trees (Populus sp.), during the cold and humid seasons of the year. We hypothesized that greater intensity of grazing would result in higher degradation of the soil system. The grazing factor had a significant effect on soil organic C and N, microbial biomass C, microbial biomass N, microbial activity, and β-glucosidase, while acid phosphatase and urease activity were not found to differ significantly among the management systems. The intensity of grazing affected mostly the chemical properties of soil (organic C and N) and altered significantly the composition of the soil microbial community, as lower C:N ratio of the microbial biomass indicates the dominance of bacteria over fungi in the heavily grazed fields. All estimated biological variables presented higher values in the humid period, although the pattern of differentiation was similar at both sampling times, revealing that site-specific variations were more pronounced than the time-specific ones. Our results indicate that not all C, N, and P dynamics were equally affected by grazing. Management plans applied to pastures, in order to improve soil quality properties and accelerate passive reforestation, should aim at the improvement of soil parameters related primarily to C and secondly to N cycle.
我们研究了不同放牧强度（重度和轻度）农田土壤功能特性的时间变化和地点间差异，并将其与相邻树篱（由木本灌木（悬钩子）或高大树木（杨树）组成）在一年中寒冷潮湿季节的土壤功能特性进行了比较。我们假设更高的放牧强度会导致土壤系统更高程度的退化。放牧因素对土壤有机碳和氮、微生物生物量碳、微生物生物量氮、微生物活性和β-葡萄糖苷酶有显著影响，而酸性磷酸酶和脲酶活性在不同管理系统之间未发现显著差异。放牧强度主要影响土壤的化学性质（有机碳和氮），并显著改变土壤微生物群落的组成，因为微生物生物量较低的碳氮比表明在重度放牧的田地中细菌比真菌占优势。所有估计的生物学变量在湿润期呈现出更高的值，尽管在两个采样时间的分化模式相似，这表明特定地点的变化比特定时间的变化更为明显。我们的结果表明，并非所有的碳、氮和磷动态都受到放牧的同等影响。为了改善土壤质量特性并加速被动造林而应用于牧场的管理计划，应旨在改善主要与碳循环相关、其次与氮循环相关的土壤参数。
