Aforest

Aforest (Effects of common European tree species on interactions between C and N processes in soil and soil biota)

Removing carbon (C) from the atmosphere to mitigate global climate change effects will be a major challenge for humanity in the 21st century. Scientists at UCHP have studied how microorganisms found in soil from leaf litter of different tree species affect soil C processes.

Since soils constitute a larger carbon (C) pool than the vegetation and atmosphere together an important strategy could be to sequester more C in soils. Plant-soil interactions play an important role for ecosystem services such as C sequestration and N retention in soil and such interactions receive increasing attention among scientists and policymakers.

Novel techniques such as next generation sequencing methods in combination with analysis of C stock patterns under different tree species present an opportunity to highlight complex processes and mechanisms which underlie C and N fluxes in soil.

The proposed research was designed to:

• Explore litter mediated effects of common European tree species on C and N turnover in soil
• Characterize effects of tree species on community structure and composition of soil biota
• Evaluate the impact of common European tree species on metabolic diversity and structure and composition of functional genes related to C and N turnover.
• To synthesize the role of soil biota for C and N turnover in soils.

The research was carried out within a unique common garden experiment with monoculture stands of six common European tree species;

• the broadleaves beech (Fagus sylvatica L.)
• pedunculate oak (Quercus robur L.)
• lime (Tilia cordata L.), sycamore maple (Acer pseudoplatanus L.)
• ash (Fraxinus excelsior L.)
• the conifer Norway spruce (Picea abies (L.) Karst.)

Our results indicated differences in soil physico-chemical properties and C and N fluxes between various tree species.

Our results revealed higher diversity of soil bacteria and fungi in soil planted by ash, maple and lime. We indicated higher bacterial growth in soils planted by ash, maple and lime while soils planted by beech, oak and spruce showed higher fungal growth.

In addition, we found higher metabolic activity in soils planted with ash, maple lime and oak, while beech and spruce showed lower metabolic activity. We also found differences in abundance and density of soil fauna.

For example, we found higher relative abundance of phylum Annelida in soils planted with beech, oak and spruce while soil planted with ash, maple and lime showed higher relative abundance of phylum Arthropoda.

Finally, we found link between litter chemistry, soil physico-chemical soil properties and relative abundance and biomass of soil biota. Results obtained from this research will contribute to bridge gaps in ecological theory in term of ecosystem functions and services.