Lopatin Javier, Araya-López Rocío, Galleguillos Mauricio, Perez-Quezada Jorge F
Faculty of Engineering and Science University Adolfo Ibáñez Santiago Chile.
Data Observatory Foundation Santiago Chile.
Ecol Evol. 2022 Mar 21;12(3):e8694. doi: 10.1002/ece3.8694. eCollection 2022 Mar.
Anthropogenic-based disturbances may alter peatland soil-plant causal associations and their ability to sequester carbon. Likewise, it is unclear how the vegetation attributes are linked with different soil C decomposition-based pools (i.e., live moss, debris, and poorly- to highly-decomposed peat) under grassing and harvesting conditions. Therefore, we aimed to assess the relationships between aboveground vegetation attributes and belowground C pools in a Northern Patagonian peatland of with disturbed and undisturbed areas. We used ordination to depict the main C pool and floristic gradients and structural equation modeling (SEM) to explore the direct and indirect relationships among these variables. In addition, we evaluated whether attributes derived from plant functional types (PFTs) are better suited to predict soil C pools than attributes derived from species gradients. We found that the floristic composition of the peatland can be classified into three categories that follow the C pool gradient. These categories correspond to (1) woody species, such as , (2) water-logged species like , and (3) grasslands. We depicted that these classes are reliable indicators of soil C decomposition stages. However, the relationships change between management. We found a clear statistical trend showing a decrease of live moss, debris, and poorly-decomposed C pools in the disturbed area. We also depicted that plant diversity, plant height, and PFT composition were reliable indicators of C decomposition only under undisturbed conditions, while the species-based attributes consistently yielded better overall results predicting soil C pools than PFT-based attributes. Our results imply that managed peatlands of Northern Patagonia with active grassing and harvesting activities, even if small-scaled, will significantly alter their future C sequestration capacities by decreasing their live and poorly-decomposed components. Finally, aboveground vegetation attributes cannot be used as proxies of soil C decomposition in disturbed peatlands as they no longer relate to decomposition stages.
基于人为因素的干扰可能会改变泥炭地土壤与植物之间的因果联系及其碳固存能力。同样，目前尚不清楚在放牧和采伐条件下，植被属性如何与基于不同土壤碳分解的库（即活苔藓、残体以及分解程度低至高的泥炭）相关联。因此，我们旨在评估巴塔哥尼亚北部泥炭地中受干扰和未受干扰区域地上植被属性与地下碳库之间的关系。我们使用排序来描绘主要的碳库和植物区系梯度，并采用结构方程模型（SEM）来探究这些变量之间的直接和间接关系。此外，我们评估了源自植物功能类型（PFTs）的属性是否比源自物种梯度的属性更适合预测土壤碳库。我们发现，泥炭地的植物区系组成可分为三类，它们遵循碳库梯度。这些类别分别对应于：（1）木本物种，如 ；（2）水生物种，如 ；（3）草原。我们描述了这些类别是土壤碳分解阶段的可靠指标。然而，管理方式不同，这些关系也会发生变化。我们发现一个明显的统计趋势，即受干扰区域的活苔藓、残体和分解程度低的碳库减少。我们还描述了植物多样性、株高和PFT组成仅在未受干扰的条件下才是碳分解的可靠指标，而基于物种的属性在预测土壤碳库方面始终比基于PFT的属性产生更好的总体结果。我们的研究结果表明，即使规模较小，但有活跃放牧和采伐活动的巴塔哥尼亚北部管理泥炭地，将通过减少其活的和分解程度低的成分，显著改变其未来的碳固存能力。最后，在受干扰的泥炭地中，地上植被属性不能用作土壤碳分解的替代指标，因为它们不再与分解阶段相关。
