Tree species identity drives soil carbon and nitrogen stocks in nutrient-poor sites

作者：Estela Covre Foltran, Norbert Lamersdorf · 发表于：Forest Ecology and Management · 年份：2024 · DOI：10.1016/j.foreco.2024.122090 · 被引用次数：8 · 研究领域：Forest ecology and management、Soil Carbon and Nitrogen Dynamics、Peatlands and Wetlands Ecology

The establishment of mixed forest stands is an option to enhance soil organic carbon stocks and to protect forest ecosystems from various impacts of climate change. Increasing temperatures and drought potentially affect the vitality of the native coniferous Norway spruce (Picea abies) , often used in mixed forests. We investigated the effects of a replacement of Norway spruce by Douglas fir ( Pseudotsuga menziesii ) admixed to European beech ( Fagus sylvatica ) on carbon (C) and nitrogen (N) concentrations and stocks, as well as the vertical distribution and changes in forest floor and mineral soil (down to 30 cm depth). Two regions with different soil conditions (loamy vs sandy soils textures) were selected, considering four sites in each region. Each site included a quintet of neighboring forest stands (>85 yrs) of European beech, Douglas fir, and Norway spruce stands as well as mixtures of beech with either Douglas fir or spruce. Our results showed that the C stocks of the organic layer were significantly influenced by tree species, while the C stock of the mineral soil varied among soil types. Total soil organic C stocks demonstrated notable species-specific characteristics, primarily driven by the elevated C stocks in the organic layer. In sandy soils, conifers and mixed forests store 10 % more C and N in the organic layer compared to loamy soils, whereas the C and N stocks under beech remained unaffected, regardless of the site condition. The interaction between species...