The dynamics of the carbon storage and fluxes in Scots pine (Pinus sylvestris) chronosequence

Veiko Uri; Mai Kukumägi; Jürgen Aosaar; Mats Varik; Hardo Becker; Kristiina Aun; Krista Lõhmus; Kaido Soosaar; Alar Astover; Marek Uri; Mikko Buht; Agnes Sepaste; Allar Padari

doi:10.1016/j.scitotenv.2022.152973

The dynamics of the carbon storage and fluxes in Scots pine (Pinus sylvestris) chronosequence

Sci Total Environ. 2022 Apr 15:817:152973. doi: 10.1016/j.scitotenv.2022.152973. Epub 2022 Jan 8.

Authors

Affiliations

¹ Estonian University of Life Sciences, Institute of Forestry and Rural Engineering, Kreutzwaldi 5, 51014 Tartu, Estonia. Electronic address: veiko.uri@emu.ee.
² University of Tartu, Institute of Ecology and Earth Sciences, Vanemuise 46, 51014 Tartu, Estonia; Estonian University of Life Sciences, Institute of Forestry and Rural Engineering, Kreutzwaldi 5, 51014 Tartu, Estonia.
³ Estonian University of Life Sciences, Institute of Forestry and Rural Engineering, Kreutzwaldi 5, 51014 Tartu, Estonia.
⁴ University of Tartu, Institute of Ecology and Earth Sciences, Vanemuise 46, 51014 Tartu, Estonia.
⁵ Estonian University of Life Sciences, Institute of Agricultural and Environmental Sciences, Kreutzwaldi 5, 51014 Tartu, Estonia.

PMID: 35007591
DOI: 10.1016/j.scitotenv.2022.152973

Abstract

To evaluate the impact of stand age on the ecosystem's C budget, as well as the post-harvest recovery of the C storages and fluxes, a chronosequence of Scots pine stands from the clear-cut stage up to the age of 110 years was studied. An age-related trend of net primary production (NPP) demonstrated effective C accumulation in the young and middle-aged stands and their levelling out thereafter. The understorey vegetation contributed 8-46% to total NPP, being lower in the pole and middle-aged stands, but without a clear age related trend. Annual cumulative soil heterotrophic respiration (Rh) demonstrated stable values along the chronosequence, varying between 3.8 and 5.4 t C ha^-1 yr^-1. The Rh flux of 2.9 t C ha^-1 yr^-1 at the clear-cut site did not exceed the corresponding value for stands. The NEP along the chronosequence followed the dynamics of the annual biomass production of the trees, peaking at the middle-aged stage and decreasing in the older stands; the NPP of the trees was the main driver directing the dynamics of NEP. There was no significant correlation between Rh and dynamics of aboveground litter or fine root production, which can partly explain why no relationship was established between annual Rh and stand age. The total ecosystem C stocks followed the same trend as cumulative tree biomass, peaking in the older stands, however, the soil C stocks varied along the chronosequence irrespective of stand age. The post-harvest C compensation point was reached at the age of 7-years and C payback occurred at a stand age of 11-12 years. Stands acted as C accumulating ecosystems and average annual C accumulation was around 2.5 t C ha^-1 yr^-1, except for the youngest stand and the clear-cut area which acted as C sources. In the oldest stand C budget was almost balanced, with a modest annual accumulation of 0.12 t C ha^-1 yr^-1.

Keywords: Carbon accumulation; Carbon budget; Carbon compensation point; Net primary production;; Scots pine chronosequence; Soil respiration.

MeSH terms

Carbon
Ecosystem
Pinus sylvestris*
Pinus*
Soil
Trees

Substances

Soil
Carbon