Cadmium pollution alters earthworm activity and thus leaf-litter decomposition and soil properties
Cadmium pollution alters earthworm activity and thus leaf-litter decomposition and soil properties
复制标题
镉污染改变蚯蚓活性，从而改变落叶分解和土壤性质
DOI：
10.1016/j.envpol.2020.115410
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发表时间：
2020
影响因子：
8.9
通讯作者：
Pan Y.
中科院分区：
文献类型：
--
作者：
Liu C.;Duan C.;Meng X.;Yue M.;Zhang H.;Wang P.;Xiao Y.;Hou Z.;Wang Y.;Pan Y.
据报道，重金属污染会通过对微生物群落的影响来影响凋落物的分解和土壤性质。然而，目前尚不清楚蚯蚓在应对重金属污染时活动的预期变化是否会影响这些特性。因此，我们量化了蚯蚓(Eisenia Fetida)对镉(Cd)致死浓度(0、50、100、150、200、250和300m g/kg−1)的存活率以及对亚致死浓度(0、15、30和45 m g/kg−1)的挖洞能力、生理特性和(杨树枯枝落叶层上的)摄食率的反应。最后，研究了Cd对杨树凋落物分解速率和土壤性质的亚致死影响。对L−-1的12、24、36、48小时半数致死量分别为276.0、208.6、192.6、179.8 mg。随着Cd浓度的增加，丙二醛受到刺激，超氧化物歧化酶呈先升高后降低的趋势，摄食率、总借用长度和最大挖深呈下降趋势。因此，凋落物分解速率和土壤养分浓度总体上随着Cd浓度的增加而降低。结果表明，Cd通过影响蚯蚓活动，抑制枯枝落叶分解，导致土壤肥力退化。这项研究强调了蚯蚓在重金属胁迫下调节土壤功能的重要性。
It has been reported that heavy metal contamination can affect litter decomposition and soil properties through its impact on microbial communities. However, it is still unclear whether the expected changes in earthworm activities in responses to heavy metal contamination could affect these properties. Therefore, we quantified earthworm (Eisenia fetida) responses in survival rate to lethal cadmium (Cd) concentrations (0, 50, 100, 150, 200, 250, and 300 mg L−1), and in burrowing ability, physiological characteristics, and feeding rate (on poplar leaf litter) to sub-lethal Cd concentrations (0, 15, 30, and 45 mg kg−1). Finally, sub-lethal influences of Cd on the decomposition rate of poplar leaf litter and on soil properties were investigated in the present ofE. fetida. The 12-, 24-, 36-, and 48-h LC50of Cd forE. fetidawere 276.0, 208.6, 192.6, 179.8 mg L−1, respectively. With increasing Cd concentration, malondialdehyde was stimulated, superoxide dismutase first increased and then decreased, while feeding rate, total borrowing length, and maximum burrowing depth consistently decreased. Consequently, leaf-litter decomposition rate and soil nutrient concentrations generally decreased with increasing Cd concentration. Our results indicate that, by affecting earthworm activities, Cd inhibited leaf-litter decomposition and led to the degradation of soil fertility. This study highlights the importance of earthworms in mediating soil functions under heavy metal stress.