Functional diversity and identity effects on forest soil carbon stocks
depend on climate contexts
- Xinli Chen,
- Masumi Hisano,
- Anthony Taylor,
- Han Chen
Han Chen
Lakehead University Faculty of Law, Lakehead University
Author ProfileAbstract
Soil carbon plays an important role in mediating global climate change
and securing food production. Despite rapid declines in plant diversity
worldwide, uncertainties remain concerning the relationships between
tree diversity and soil carbon stock in natural forests, as well as the
climatic factors that drive their directions and magnitudes. Using
Canada's National Forest Inventory data, we tested the relationships
between soil carbon stocks to tree functional diversity and identity,
and how these relationships varied with stand age and climate gradients
in the organic horizon, mineral horizon and entire soil profile. We
found that the effects of functional diversity on soil carbon stocks
were highly climate-dependent, shifting from negative in warm or moist
climates to positive or null in cold and dry climates. In addition, tree
species with acquisitive traits, such as high specific leaf area, leaf
nitrogen content and phosphorus content, increased mineral soil carbon
stocks in warmer sites, but decreased those in colder sites. Our results
suggest that tree diversity effects on soil carbon are strongly
dependent on climate context and promoting high functional diversity is
important to increase soil carbon stocks of colder and drier sites in
boreal and temperate forests.