Near-term investments in forest management support long-term carbon sequestration capacity in forests of the United States

Abstract

The forest carbon sink of the United States offsets emissions in other sectors. Recently passed US laws include important climate legislation for wildfire reduction, forest restoration, and forest planting. In this study, we examine how wildfire reduction strategies and planting might alter the forest carbon sink. Our results suggest that wildfire reduction strategies reduce carbon sequestration potential in the near term but provide a longer term benefit. Planting initiatives increase carbon sequestration but at levels that do not offset lost sequestration from wildfire reduction strategies. We conclude that recent legislation may increase near-term carbon emissions due to fuel treatments and reduced wildfire frequency and intensity, and expand long-term US carbon sink strength.

Keywords: climate legislation; climate mitigation; forest carbon projections; natural climate solutions.

Fig. 1.

A) Forested NFI plot locations (approximate) and ownership. B) illustrates fire sheds [12] used to identify western forest fuel treatment locations [7]. C) The fuel treatments within priority fire sheds targeted overstocked and fully stocked USFS land and in other ownerships. Nonstocked USFS land was targeted for planting. D) Projections were based on two different fuel-treatment levels, planting, and five different climates under Shared Socioeconomic Pathway 2. The fuel treatments apply a tree basal area reduction and/or dead fuel weight reduction; E) depicts a western forest stand with 46 m² ha⁻¹ of basal area, thinned to 23 m² ha⁻¹, displaying cut and unutilized trees F) and the resulting forest without cut trees G).

Fig. 2.

Historic and projected US aboveground carbon stocks for the baseline, FLT, and FHT scenarios A) from 2019 to 2050, with shaded areas displaying model and climate variability. B) The effects of the fuel treatments and planting from 2022 to 2032. Projected US forest mitigation potential under FLT, FHT, and planting scenarios in 2032 and 2050 (C; length of each bar indicating model and climate variability). The distribution of projected cumulative aboveground carbon sequestration in 2050 for the United States under baseline, planting, FLT, and FHT scenarios D). In E), uncertainty components show variability driven by the forest projection model, alternative general circulation models, and fuel management intensity (FLT vs. FHT).