Local-scale Arctic tundra heterogeneity affects regional-scale carbon dynamics.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33004822.
- Also identified by DOI 10.1038/s41467-020-18768-z and PMC identifier 7529807.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
In northern Alaska nearly 65% of the terrestrial surface is composed of polygonal ground, where geomorphic tundra landforms disproportionately influence carbon and nutrient cycling over fine spatial scales. Process-based biogeochemical models used for local to Pan-Arctic projections of ecological responses to climate change typically operate at coarse-scales (1km<sup>2</sup>-0.5°) at which fine-scale (<1km<sup>2</sup>) tundra heterogeneity is often aggregated to the dominant land cover unit. Here, we evaluate the importance of tundra heterogeneity for representing soil carbon dynamics at fine to coarse spatial scales. We leveraged the legacy of data collected near Utqiaġvik, Alaska between 1973 and 2016 for model initiation, parameterization, and validation. Simulation uncertainty increased with a reduced representation of tundra heterogeneity and coarsening of spatial scale. Hierarchical cluster analysis of an ensemble of 21<sup>st</sup>-century simulations reveals that a minimum of two tundra landforms (dry and wet) and a maximum of 4km<sup>2</sup> spatial scale is necessary for minimizing uncertainties (<10%) in regional to Pan-Arctic modeling applications.