Assessing Baseline Carbon Stocks for Forest Transitions: A Case Study of Agroforestry Restoration from Hawaiʻi

Abstract

As the extent of secondary forests continues to expand throughout the tropics, there is a growing need to better understand the ecosystem services, including carbon (C) storage provided by these ecosystems. Despite their spatial extent, there are limited data on how the ecosystem services provided by secondary forest may be enhanced through the restoration of both ecological and agroecological functions in these systems. This study quantifies the above- and below-ground C stocks in a non-native secondary forest in Hawaiʻi where a community-based non-profit seeks to restore a multi-strata agroforestry system for cultural and ecological benefits. For soil C, we use the equivalent soil mass method both to estimate stocks and examine spatial heterogeneity at high resolution (eg. sub 5 m) to define a method and sampling design that can be replicated to track changes in C stocks on-site and elsewhere. The assessed total ecosystem C was ~388.5 Mg C/ha. Carbon stock was highest in trees (~192.4 Mg C/ha; ~50% of total C); followed by soil (~136.4 Mg C/ha; ~35% of total C); roots (~52.7 Mg C/ha; ~14% of total C); and was lowest in coarse woody debris (~4.7 Mg C/ha; ~1% of total C) and litter (~2.3 Mg C/ha; <1% of total C). This work provides a baseline carbon assessment prior to agroforest restoration that will help to better quantify the contributions of secondary forest transitions and restoration efforts to state climate policy. In addition to the role of C sequestration in climate mitigation, we also highlight soil C as a critical metric of hybrid, people-centered restoration success given the role of soil organic matter in the production of a suite of on- and off-site ecosystem services closely linked to local sustainable development goals.

The spatiotemporal patterns and pathways of forest transition in China

“…Here, we account for an additional dimension of forest ecosystems (forest volume) that is linked to forest transition processes. We suggest that more attention should be paid to investigate trends in forest health, forest quality (Gu et al, 2021), and the provision of forest ecosystem services (Melone et al, 2021; Wilson et al, 2017) in regions experiencing forest transitions. For instance, forest transition driven by large‐scale timber plantings may have a marginal impact on aggregated biodiversity or carbon storage sustainability targets if deforestation of primary forests continues.…”

Determining Allometry and Carbon Sequestration Potential of Breadfruit (Artocarpus altilis) as a Climate-Smart Staple in Hawai‘i

“…Contemporarily, breadfruit is often grown in agroforestry settings, supporting a broad range of ecological and social outcomes [35][36][37]. Among the enhanced benefits of diversified agroforestry include additional carbon sequestration in both biomass and soil carbon stocks [38]. While the study of breadfruit allometry provides a starting point for understanding carbon in such systems, additional work is essential to support agricultural transitions to more sustainable systems of food production.…”

Cap. 30. Hawái y las Islas del Pacífico Afiliadas a los Estados Unidos. En: La Quinta Evaluación Nacional del Clima

“…Algunos ejemplos de adaptación basada en el conocimiento indígena son la agrosilvicultura, la agricultura de taro en humedales, los estanques piscícolas y las reglas de pesca, como los períodos de descanso 116,117,118,119 . La conservación de manglares y hierbas marinas y la agricultura regenerativa demuestran un alto potencial para el secuestro de carbono (KM 30.4) 120,121,122 17.4). La red Local2030 de las islas está formando comunidades de práctica regionales en torno a la energía, los datos, el turismo y otros temas de interés, y está poniendo a prueba los paneles de las SDG en Guam, Hawái y Palaos (KM 18.4).…”