Changes in soil biogeochemistry following disturbance by girdling and mountain pine beetles in subalpine forests.
Changes in soil biogeochemistry following disturbance by girdling and mountain pine beetles in subalpine forests.
复制标题
亚高山森林环剥和山松甲虫干扰后土壤生物地球化学的变化。
DOI：
10.1007/s00442-015-3227-4
复制
发表时间：
2015
期刊：
影响因子：
2.7
通讯作者：
Trahan NA
中科院分区：
文献类型：
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作者：
Trahan NA
最近，在北美西部的黑松森林中发生了一场前所未有的流行病，由甲虫引起的树木死亡。在这里，我们提出了在落基山脉的两个亚高山森林的研究结果，一个经历了自然松甲虫的干扰和一个经历了模拟干扰通过树干环剥。我们评估了变化的土壤小气候和土壤地球化学池的地块代表不同的干扰后的时间序列。高情节树死亡率，无论是由于环剥或甲虫侵扰，造成类似的土壤养分库的变化。在干扰后的前4年，观察到土壤溶解有机碳（DOC）浓度（45- 51%），微生物量碳浓度（33- 39%），溶解有机氮（DON）浓度（31- 42%）和无机磷（PO 43 −）浓度（53- 55%）急剧下降。扰动后5 ~ 6年，DOC、DON和PO 43-的浓度恢复到未扰动样地的71- 140%。恢复与观察到的增加，凋落物深度和亚凋落物，土壤O-层。在4年的干扰，土壤铵，但不是硝酸盐，增加到2-3倍的水平，在未受干扰的地块。微生物量N增加的地块，增加铵。我们的研究结果表明，先前观察到的下降，土壤呼吸甲虫引起的干扰伴随着损失的关键土壤养分。土壤养分库的恢复发生在几年后的干扰，并与渐进矿化的死树凋落物。
A recent unprecedented epidemic of beetle-induced tree mortality has occurred in the lodgepole pine forests of Western North America. Here, we present the results of studies in two subalpine forests in the Rocky Mountains, one that experienced natural pine beetle disturbance and one that experienced simulated disturbance imposed through bole girdling. We assessed changes to soil microclimate and biogeochemical pools in plots representing different post-disturbance chronosequences. High plot tree mortality, whether due to girdling or beetle infestation, caused similar alterations in soil nutrient pools. During the first 4 years after disturbance, sharp declines were observed in the soil dissolved organic carbon (DOC) concentration (45–51 %), microbial biomass carbon concentration (33–39 %), dissolved organic nitrogen (DON) concentration (31–42 %), and inorganic phosphorus (PO43−) concentration (53–55 %). Five to six years after disturbance, concentrations of DOC, DON, and PO43−recovered to 71–140 % of those measured in undisturbed plots. Recovery was coincident with observed increases in litter depth and the sublitter, soil O-horizon. During the 4 years following disturbance, soil ammonium, but not nitrate, increased to 2–3 times the levels measured in undisturbed plots. Microbial biomass N increased in plots where increased ammonium was available. Our results show that previously observed declines in soil respiration following beetle-induced disturbance are accompanied by losses in key soil nutrients. Recovery of the soil nutrient pool occurs only after several years following disturbance, and is correlated with progressive mineralization of dead tree litter.