Carbon benefits through fallow agricultural land transitions: the case of multi-strata agroforestry in Hawai‘i

Agroforestry, Ecosystem Services, Leah Bremer, Environment, Working Papers

RESEARCH PAPERS ARE PRELIMINARY MATERIALS CIRCULATED TO STIMULATE DISCUSSION AND CRITICAL COMMENT. THE VIEWS EXPRESSED ARE THOSE OF THE INDIVIDUAL AUTHORS. WHILE RESEARCH PAPERS BENEFIT FROM ACTIVE UHERO DISCUSSION, THEY HAVE NOT UNDERGONE FORMAL ACADEMIC PEER REVIEW.

There are growing efforts to incorporate agroforestry into ecosystem service incentive programs. Indigenous and other place-based multi-strata agroforestry systems are important conservation and agricultural strategies, yet their ecosystem services, including carbon sequestration benefits, have received little research attention. To fill this gap, we draw on interviews with agroforestry practitioners and ecosystem service modeling in Hawaiʻi to: 1) create future scenarios of where fallow agricultural lands and non-native dominated conservation lands could be transitioned to multi-strata agroforestry under current and future climates; and 2) quantify the potential above-ground carbon and soil carbon benefits and tradeoffs of transitions across these scenarios. Mean above-ground carbon in modeled agroforestry systems was estimated to be 92-125 Mg C ha-1 (337-458 Mg CO2 ha-1) with ~73% of the potential area significantly increasing above-ground carbon storage. Significant benefits for both above-ground and soil carbon are projected across 37-45% of the area transitioned to agroforestry, with just 4-5% of area with expected overall losses. With potential above-ground carbon sequestration similar or greater than that of native forest restoration, restoration through agroforestry represents an important pathway to achieving ecological, cultural, and economic benefits on large areas of fallow agricultural and non-native dominated conservation lands, offering a pathway to support inclusive and effective natural climate solutions.