Linking litter calcium, earthworms and soil properties: a common garden test with 14 tree species

TLDR

Tree species shape soil biogeochemistry through differences in litter quantity and chemistry, yet the influence of specific plant traits and the gymnosperm–angiosperm contrast remains poorly understood. The study aimed to evaluate how 14 gymnosperm and angiosperm tree species affect soil properties after 30 years of monoculture and to determine the contribution of litter chemistry to these effects. Researchers used a replicated, long‑term monoculture plot experiment to compare soil variation among the species and assess litter chemistry’s role. Litter calcium differences among species produced marked shifts in soil acidity and fertility, and calcium‑rich species supported higher earthworm abundance and diversity, elevated soil pH, exchangeable calcium, base saturation, and forest floor turnover.

Abstract

Abstract Tree species can influence biogeochemistry through variation in the quantity and chemistry of their litter, and associated impacts on the soil heterotrophic community. However, the role that different plant traits play in these processes is not well understood, nor is it clear whether species effects on soils largely reflect a gymnosperm vs. angiosperm contrast. Using a replicated, long‐term monoculture plot experiment, we examined variation in soils among 14 gymnosperm and angiosperm tree species 30 years after plot establishment, and assessed the role of litter chemistry vis‐à‐vis such variation. Differences in litter calcium concentrations among tree species resulted in profound changes in soil acidity and fertility that were similar within and among tree groups. Tree species rich in calcium were associated with increased native earthworm abundance and diversity, as well as increased soil pH, exchangeable calcium, per cent base saturation and forest floor turnover rate.