Carbon Sequestration Using Exotic Larches in Central Maine

Abstract

The carbon sequestration potential of exotics might be considered as one of the several alternatives for forest adaptation to climate change. The results presented here demonstrate that exotic larches’ (Larix spp.) growth rates for both carbon accumulation and traditional forest products exceed those of both natural regeneration and other planted species when planted on a good site in Maine. Recent re-measurement of a species-site trial established in 1988 represents the 34th growing season. Species included Black Spruce (BS) (Picea mariana Mill.), European larch (EL) (Larix decidua Mill.), hybrid larch (HL) (L. x marschelensi), Japanese larch (JL) (L. kaempferi (Lam.) Carrière), Jack pine (JP) (Pinus banksiana Lamb.), Red pine (RP) (Pinus resinosa Ait.), Tamarack (TL) (L. larcinia (Du Roi) K. Koch), and White spruce (WS)(Picea glauca (Moench) Voss). All three of the exotic larches outgrew the other species. Hybrid larch had over nearly twice the merchantable volume (m3 ha−1) and over three times the sawlog volume (green tonnes ha−1) than Red pine. Hybrid larch had the highest growth rate at age 34, over 20 m3 per hectare per year (nearly 3.3 cords ac−1 year−1 or 6.8 tons−1 acre−1 year−1). The other two exotic larches are growing at over 19 m3 ha−1 year−1 (3 cords acre−1 year−1 or 6.4 tons acre−1 year−1). Converting these growth rates to accumulation of CO2eq over the 34-year period produces stunning contrasts compared to native species. Over the 34-year period, larch hybrids sequestered 2.4 times as much CO2eq as the untreated plots (444 vs. 186 tonnes−1 ha−1). We discuss practical implications for forest management and carbon policies.