Forest management impacts on greenhouse gas fluxes from riparian soils along headwater streams

This data supports the 2021 publication "Forest management impacts on greenhouse gas fluxes from riparian soils along headwater streams" in Ecosystems. Abstract: Increasing concentrations of atmospheric greenhouse gases (GHGs; CO2, CH4, N2O) causes climate change. Depending on the conditions, soils have the potential to store carbon or to be a source of GHGs to the atmosphere. Riparian soils in particular have high potential to store carbon, but also to be sources of CH4 and N2O. Headwater streams make up a large proportion of stream length in a drainage network, and their riparian zones have valuable ecosystem functions. In parallel, the riparian zones of headwater streams are particularly vulnerable to forest harvest. Studies of GHG fluxes from these unique ecosystems remain limited. Our objective was to quantify the effects of forestry practices and groundwater discharge (DIS) areas on GHG emissions from riparian forest soils in coastal British Columbia. We compared nine sites with three different forest management protocols: 1) harvesting with a riparian buffer, 2) no buffer, and 3) reference sites without harvesting. We measured gas fluxes, soil temperature, soil moisture and depth to the groundwater table alongside headwater streams monthly over one growing season. We found that CH4 uptake rates were 65% lower at the no buffer sites, and N2O emission rates were 52% lower at the no buffer sites, when compared to the reference sites. Additionally, CH4 uptake was 54% lower at DIS areas than in non-DIS areas. The results of our research help inform forest management by demonstrating that maintaining riparian buffers can be effective in protecting the ecosystem functions contributing to soil GHG fluxes.

本数据集支撑发表于《Ecosystems》2021年的论文《森林管理对源头溪流（headwater streams）沿岸河岸土壤温室气体通量的影响》。
摘要：大气温室气体（greenhouse gases, GHGs；涵盖CO₂、CH₄、N₂O）浓度持续上升会引发气候变化。土壤会根据环境条件的不同，兼具碳固存与向大气排放温室气体的潜力。河岸土壤不仅具备极强的碳固存能力，同时也可能成为CH₄与N₂O的排放源。源头溪流（headwater streams）在流域水系的总河长中占比极高，其沿岸带具备重要的生态系统服务功能。与此同时，源头溪流的沿岸带对森林采伐活动尤为敏感。目前针对这类特殊生态系统的温室气体通量研究仍较为匮乏。
本研究旨在量化林业经营措施与地下水补给区（groundwater discharge, DIS）对不列颠哥伦比亚省沿海地区河岸森林土壤温室气体排放的影响。本研究选取9处样地，涵盖3种不同的森林经营方案：1）保留河岸缓冲带的采伐样地，2）未保留河岸缓冲带的采伐样地，3）未进行采伐的对照样地。在一个生长季内，每月对源头溪流沿岸的气体通量、土壤温度、土壤含水量以及地下水位埋深进行测定。
研究结果显示，与对照样地相比，未保留缓冲带的样地CH₄吸收速率降低65%，N₂O排放速率降低52%。此外，地下水补给区的CH₄吸收速率较非补给区低54%。本研究结果证实，保留河岸缓冲带可有效保护影响土壤温室气体通量的生态系统服务功能，可为森林经营管理提供科学参考。