Soils at the temperate forest edge: An investigation of soil characteristics and carbon dynamics
Soils at the temperate forest edge: An investigation of soil characteristics and carbon dynamics
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DOI：
10.1016/j.scitotenv.2023.164320
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发表时间：
2023-06-09
影响因子：
9.8
通讯作者：
Hutyra，Lucy R.
中科院分区：
文献类型：
--
作者：
Garvey，Sarah M.;Templer，Pamela H.;Hutyra，Lucy R.
通过人为土地使用变化和森林破碎化造成的森林边缘的全球扩散已有详细记录，虽然森林破碎化对土壤碳循环有明显影响，但对森林边缘地下活动的潜在驱动因素仍知之甚少。增加土壤C lossesvia呼吸已被观察到在农村森林边缘，但这一过程被抑制在城市森林边缘。我们提供了一个全面的，耦合的非生物土壤条件和生物土壤活性的调查，从森林边缘到内部在8个站点沿着城市化梯度，以阐明环境压力如何与土壤碳循环在森林边缘。尽管城市和农村的网站之间的边缘土壤碳损失显着的分歧趋势，我们没有发现可比的差异，土壤% C或微生物酶活性，这表明一个意想不到的脱钩土壤碳通量和池在森林边缘。我们表明，在整个站点类型，森林边缘的土壤酸性低于森林内部（p< 0.0001），土壤pH值与土壤钙，镁和钠含量呈正相关（adjR 2 = 0.37），这也是在边缘升高。与森林内部相比，森林边缘土壤的含砂量增加了17.8%，冻融频率升高，可能对根系周转和分解产生下游影响。使用这些和其他新的森林边缘数据，我们证明了边缘土壤呼吸（adjR 2 = 0.46;p= 0.0002）和C含量（adjR 2 = 0.86;p< 0.0001）的显着变化可以用经常由人类活动介导的土壤参数来解释（例如，土壤pH值、微量金属和阳离子浓度、土壤温度），我们强调森林边缘多个同时发生的全球变化驱动因素的复杂影响。森林边缘土壤反映了人类土地利用和现代人类管理的遗产，这必须考虑到了解土壤活动和碳循环在破碎的景观。
Global proliferation of forest edges through anthropogenic land-use change and forest fragmentation is well documented, and while forest fragmentation has clear consequences for soil carbon (C) cycling, underlying drivers of belowground activity at the forest edge remain poorly understood. Increasing soil C lossesviarespiration have been observed at rural forest edges, but this process was suppressed at urban forest edges. We offer a comprehensive, coupled investigation of abiotic soil conditions and biotic soil activity from forest edge to interior at eight sites along an urbanization gradient to elucidate how environmental stressors are linked to soil C cycling at the forest edge. Despite significant diverging trends in edge soil C losses between urban and rural sites, we did not find comparable differences in soil % C or microbial enzyme activity, suggesting an unexpected decoupling of soil C fluxes and pools at forest edges. We demonstrate that across site types, soils at forest edges were less acidic than the forest interior (p< 0.0001), and soil pH was positively correlated with soil calcium, magnesium and sodium content (adjR2= 0.37), which were also elevated at the edge. Compared to forest interior, forest edge soils exhibited a 17.8 % increase in sand content and elevated freeze-thaw frequency with probable downstream effects on root turnover and decomposition. Using these and other novel forest edge data, we demonstrate that significant variation in edge soil respiration (adjR2= 0.46;p= 0.0002) and C content (adjR2= 0.86;p< 0.0001) can be explained using soil parameters often mediated by human activity (e.g., soil pH, trace metal and cation concentrations, soil temperature), and we emphasize the complex influence of multiple, simultaneous global change drivers at forest edges. Forest edge soils reflect legacies of anthropogenic land-use and modern human management, and this must be accounted for to understand soil activity and C cycling across fragmented landscapes.