Relationships between soil nematode communities and soil
multifunctionality as affected by land-use type
Abstract
Researchers have used both soil nematode data and soil
multifunctionality data as indicators of soil quality. However, the
relationship between soil nematodes and soil multifunctionality is
poorly understood. This study explored the relationship between soil
nematode properties and soil multifunctionality in different land-use
types in a subtropical karst region of Southwest China. We selected the
following five typical land-use types that differ in the degree of soil
disturbance: cropland (maize-soybean), sugarcane, mulberry, forage
grass, and forest. Soil multifunctionality was calculated based on bulk
density (BD), soil pH, the ratio of soil organic carbon to total
nitrogen (C: N), the contents of soil water (SWC), soil total nitrogen
(TN), soil organic carbon content (SOC), calcium (Ca), magnesium (Mg),
microbial biomass carbon (MBC), microbial biomass nitrogen (MBN),
ammonium nitrogen (AN), and nitrate nitrogen (NN). We found that the
abundance, Simpson dominance index, and metabolic footprint of soil
nematodes were highest in the forest, followed by sugarcane, cropland
(maize-soybean) and forage grass, and mulberry. Soil multifunctionality
was significantly higher in the forest than in the other land-use types.
Soil multifunctionality was positively correlated with the abundance of
total nematodes and all nematode trophic groups except omnivores. A
random forest model revealed that the dominant nematode genera (i.e.,
Coomansus and Acrobeloides) and the rare genera (i.e.,
Wilsonema and Heterocephalobus) were closely associated
with soil multifunctionality. Our results suggest that the soil
nematodes (especially keystone genera) may mediate the effects of
ecosystem disturbance on soil multifunctionality. These findings
increase our understanding of the relationships between soil organisms
and soil multifunctionality.