Tree diversity regulates soil respiration through elevated tree growth in a microcosm experiment

Area of Science:

• Ecology
• Soil Science
• Forestry

Background:

• Soil respiration is a key process in terrestrial carbon (C) cycling.
• Understanding aboveground-belowground interactions, particularly tree diversity's impact on soil respiration, remains limited.
• Tree diversity's role in regulating soil C dynamics requires further investigation.

Purpose of the Study:

• To investigate the effect of tree diversity on soil respiration.
• To identify the mechanisms, such as tree growth and litter decomposition, mediating tree diversity's influence on soil respiration.
• To explore how tree traits and diversity regulate ecosystem carbon balance.

Main Methods:

• A 105-day microcosm experiment was conducted in a climate chamber.
• The experiment tested the effects of varying tree species richness (1, 2, and 4 species) on soil respiration.
• Path analysis was used to determine the mechanisms driving observed effects.

Main Results:

• Soil respiration rates differed among individual tree species and increased with tree species richness.
• Tree growth was identified as the primary mechanism influencing soil respiration and explaining the diversity effect.
• Litter mass loss, an indicator of decomposition, did not significantly explain the observed diversity effects on soil respiration.

Conclusions:

• Tree diversity significantly enhances soil respiration, with tree growth being the main driver.
• Tree species richness and traits play a crucial role in regulating ecosystem carbon dynamics.
• Future research should consider tree diversity and traits when assessing carbon storage and release in terrestrial ecosystems.