April 29, 2024
Urban Forest Edge Experiences Lower Soil Moisture and Accelerated Carbon Cycling
A unique study identified the contribution of belowground soil processes to increased forest productivity at an urban-suburban forest edge.
Soil moisture at 15- and 75-cm depth for different landscape positions.
[Reprinted under a Creative Commons Attribution 4.0 International License (CC BY 4.0) from Abramoff, R. Z., et al. "Shifts in Belowground Processes Along a Temperate Forest Edge." Landscape Ecology 39, 100 (2024). DOI:10.1007/s10980-024-01891-3.]
The Science
This study aimed to understand how belowground processes influence carbon and water cycling at an urban-suburban forest edge. A team of researchers measured live and dead fine root traits, as well as soil enzyme activity, chemistry, moisture, and respiration along a 75-m urban-suburban transect from the interior of a forest, across the forest’s edge, and into a meadow at the National Institute of Standards and Technology facility in Gaithersburg, Md. Soil carbon content was similar between transect positions, but the forest edge was drier, had higher dead root biomass and sugar degradation enzyme potential activity, and had greater total soil respiration compared to the meadow and interior forest.
The Impact
Forests become exposed due to road building, urbanization, logging, and other landscape disturbances that enhance fragmentation. Forests edges are exposed to higher sunlight and increased temperatures compared to the interior of forest stands. The predominance and acceleration of forest edge formation supports investigations to understand impacts on carbon cycling and storage. Examining both above- and belowground processes is important to fully understand controls and effects of forest fragmentation.
Summary
Researchers found soil respiration carbon losses and increased sugar decomposition enzyme activities at the forest edge were possibly balanced by increased plant productivity and concomitant increased inputs to soil. Lower soil moisture may have also inhibited microbial decomposition of organic materials delivered to soils. This study suggests the forest edge experiences accelerated rates of carbon cycling and lower soil moisture levels, which is consistent with observed patterns in temperate deciduous forests but different from tropical and boreal forest edges.
Principal Investigator
Melanie Mayes
Oak Ridge National Laboratory
[email protected]
Program Manager
Daniel Stover
U.S. Department of Energy, Biological and Environmental Research (SC-33)
Environmental System Science
[email protected]
Funding
This research was sponsored by the Environmental System Science program within the U.S. Department of Energy (DOE) Biological and Environmental Research program. Oak Ridge National Laboratory is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with DOE. Support was also received from the Sitka Center for Art and Ecology.
Related Links
References
Abramoff, R. Z., et al. "Shifts in Belowground Processes Along a Temperate Forest Edge." Landscape Ecology 39, 100 (2024). https://doi.org/10.1007/s10980-024-01891-3.