Department of Environmental Sciences, University of Helsinki, Niemenkatu 73, 15140 Lahti, Finland.
Sci Total Environ. 2015 Jun 15;518-519:320-7. doi: 10.1016/j.scitotenv.2015.03.018. Epub 2015 Mar 12.
The effects of shooting-derived lead (Pb) on the structure and functioning of a forest ecosystem, and the recovery of the ecosystem after range abandonment were studied at an active shotgun shooting range, an abandoned shooting range where shooting ceased 20 years earlier and an uncontaminated control site. Despite numerous lead-induced changes in the soil food web, soil processes were only weakly related to soil food web composition. However, decomposition of Scots pine (Pinus sylvestris) needle litter was retarded at the active shooting range, and microbial activity, microbial biomass and the rate of decomposition of Pb-contaminated grass litter decreased with increasing soil Pb concentrations. Tree (P. sylvestris) radial growth was suppressed at the active shooting range right after shooting activities started. In contrast, the growth of pines improved at the abandoned shooting range after the cessation of shooting, despite reduced nitrogen and phosphorus contents of the needles. Higher litter degradation rates and lower Pb concentrations in the topmost soil layer at the abandoned shooting range suggest gradual recovery after range abandonment. Our findings suggest that functions in lead-contaminated coniferous forest ecosystems depend on the successional stage of the forest as well as the time since the contamination source has been eliminated, which affects, e.g., the vertical distribution of the contaminant in the soil. However, despite multiple lead-induced changes throughout the ecosystem, the effects were rather weak, indicating high resistance of coniferous forest ecosystems to this type of stress.
研究了射击衍生的铅（Pb）对森林生态系统结构和功能的影响，以及在废弃射击场关闭 20 年后生态系统的恢复情况。尽管土壤食物网受到了大量的铅诱导变化，但土壤过程与土壤食物网组成的关系很弱。然而，在活跃的射击场，苏格兰松（Pinus sylvestris）针叶凋落物的分解被延迟，随着土壤 Pb 浓度的增加，微生物活性、微生物生物量和受 Pb 污染的草凋落物的分解速率下降。在射击活动开始后，活跃的射击场的树木（P. sylvestris）径向生长受到抑制。相比之下，尽管废弃射击场的针叶氮磷含量降低，但在射击停止后，松树的生长得到了改善。废弃射击场土壤表层更高的凋落物降解率和更低的 Pb 浓度表明，废弃后逐渐恢复。我们的研究结果表明，受 Pb 污染的针叶林生态系统的功能取决于森林的演替阶段以及污染来源消除的时间，这会影响污染物在土壤中的垂直分布等。然而，尽管整个生态系统中发生了多种 Pb 诱导的变化，但影响相对较弱，这表明针叶林生态系统对这种压力具有很高的抵抗力。
