Background
Solidago canadensis
is a notorious invasive species from North America that is spreading across East China. It is invading some coastal grasslands and replacing native grass species. The effects of the
S. canadensis
invasion on soil nutrient cycling in the grasslands remain unclear. This study examined the effects of the invasion of
S. canadensis
on macronutrient accumulation in species aboveground part and soil.
Methods
Aboveground biomass, macronutrient (N, P, and K) pools in biomass, litter mass and decomposition rates, soil macronutrient availability and soil microbial biomass and enzyme activity that were related to nutrient transformation were compared between plots invaded by
S. canadensis
and uninvaded plots dominated by three different native grass species:
Phacelurus latifolius
,
Phragmites australis
, and
Imperata cylindrica
.
Results
S. canadensis
had higher aboveground biomass, higher leaf N, P, and K concentrations, and consequently, a larger macronutrient pool size in the standing biomass.
S. canadensis
also produced more litter with higher N, P, and K concentrations and faster decomposition rates. The
S. canadensis
invasion did not change the total N, P, and K concentration in the topsoil (0–10 cm), but the invasion did increase their availability. The
S. canadensis
invasion did not increase the total soil organic matter (TSOM) content but did increase the soil microbial biomass and the activities of urease, alkaline phosphatase, invertase, amylase, and glucosidase in the topsoil.
Conclusion
The invasion of
S. canadensis
accelerates the macronutrient cycling rate via increases in aboveground productivity and nutrient accumulation in standing biomass, faster nutrient release from litter and higher soil microbial activity. An enhanced nutrient cycling rate may further enhance its invasiveness through a positive feedback on soil processes.