Different contributions of plant traits and soil properties to the
efficiency of carbon sequestration between two restoration approaches in
a boreal forest
Abstract
Forestation plays a pivotal role in mitigating climate change by
capturing a substantial fraction of CO2 emitted by activities. However,
the efficiency of carbon (C) sequestration for different restoration
approaches such as planted forests (PFs) and naturally regenerated
forests (NRFs) remains unclear, causing large uncertainty in climate
projections. A terrestrial ecosystem model framework, which combined the
Bayesian approach with a traceability method, was used to identify the
efficacy of C sequestration in four NRFs and two PFs after 54-years of
reforestation in the boreal forest of northeastern China. The results
showed that the rate of C accumulation among the six forests ranged from
135.1 (Mongolian oak) to 400.3 g C m-2 year-1 (Dahurian larch) in the
period of 2015-2100. The two highest total C storage values at the end
of the projection period were Dahurian larch forest (57.9 ± 1.59 kg C
m-2, PFs) and hardwood forest (53.8 ± 3.01 kg C m-2, NRFs), which were
mainly the result of net primary production (NPP, 749.1 ± 47.2 g C m-2
year-1) and ecosystem C residence time (ζE, 101 ± 5
years), respectively. The efficiency of C sequestration in PFs was found
to be more influenced by plant traits, especially NPP, as well as the
turnover rate of foliage and carbon allocation to wood. In contrast, the
efficiency of C sequestration in NRFs was more correlated to the
residence time of soil organic carbon, the C:N ratio of litter, and the
content of soil inorganic nitrogen. The study highlights the different
contributions of plants and soil to carbon storage in PFs and NRFs and
advances our understanding of C accumulation between PFs and NRFs
forests in long term under the same climate condition. Our findings
provide valuable guidance for designing reforestation strategies aimed
at enhancing the terrestrial carbon sink in the future climates.