Plant functional traits modulate the effects of soil acidification on above- and belowground biomass

Abstract. Atmospheric sulfur (S) deposition has been extensively recognized as a major driving force of soil acidification. However, little is known on how soil acidification influences above- and belowground biomass via altering leaf and root traits.

A 3-year elemental S addition were conducted to simulate soil acidification in a meadow. Grass (Leymus chinensis) and sedge (Carex duriuscula) species were chosen to demonstrate the linkage between plant traits and biomass.

Sulfur addition led to soil acidification and nutrient imbalance. For L. chinensis, soil acidification decreased specific leaf area but increased leaf dry matter content showing a conservative strategy and thus suppression of aboveground instead of belowground biomass. For C duriuscula, soil acidification increased plant height and root nutrients (N, P, S, and Mn) for competing resources by investing more on above- and belowground biomass, i.e., an acquisitive strategy. An overall reduction in community aboveground biomass by 3–33 % was resulted from the increased soil acidity. While the community root biomass increased by 11–22 % as upregulated by higher soil nutrient availability.

Our results provide new insights that plant above- and belowground biomass is conditioned by S-invoked acidification and their linkages with plant traits contributed to a deeper understanding of plant-soil feedback.