Agricultural practices and deforestation are major contributors to global greenhouse gas emissions, accounting for approximately 24% of the total anthropogenic output. The expansion of agriculture, often for the global food industry, is a primary driver of deforestation worldwide. A crucial challenge facing humanity is how to sustainably feed a growing population while minimizing, or potentially reversing, the negative impacts on ecosystems. This includes efforts to enhance ecosystem functions such as carbon sequestration and storage.
Historically, the early inhabitants of the remote Pacific Islands faced similar challenges. As their populations expanded, they had to develop agricultural strategies that avoided complete ecosystem collapse. Key to their success was the integration of forest management and arboriculture, which not only provided food but also preserved the ecosystem’s integrity.
A notable example of this approach is the cultivation of breadfruit (Artocarpus altilis), a tree producing large, starchy fruits, which originated in Papua New Guinea and was spread throughout Polynesia. Despite its historical importance and recent recognition for its potential in climate-smart agriculture and global hunger solutions, breadfruit and its agroforestry applications remain under-researched.
Breadfruit trees, as a long-lived tropical species, offer significant benefits for climate-smart agriculture, particularly in carbon mitigation, adaptation, and resilience. These trees can sequester carbon in their biomass. Moreover, breadfruit cultivation often incorporates practices like reduced tillage and co-cropping, further enhancing carbon storage and sequestration in the soil. Nutritionally, breadfruit is a rich source of complex carbohydrates, vitamins, minerals, and amino acids. Socioeconomically, it supports home food security and can reduce annual labor needs, thereby improving quality of life.
Breadfruit’s potential makes it a prime candidate for carbon market projects. However, the development of carbon accounting protocols for agricultural and agroforestry projects is still evolving. Current protocols, often based on publications from organizations like the IPCC and Verified Carbon Standard, do not fully represent tropical and indigenous crops like breadfruit. As a result, there is a need for tailored research to adapt these protocols to specific contexts, such as breadfruit agroforestry.
Assessing forest biomass accurately is crucial for various applications, including wood extraction and tracking changes in carbon stocks. Allometric models, which link tree dimensions with dry mass, remain the primary method for estimating tree biomass. These models, traditionally derived from destructive sampling, are accurate but costly and time-consuming. Alternative methods include detailed measurements and remote sensing technologies like LiDAR. Statistical methods focus on data trends and correlation coefficients.
This paper presents the application of carbon accounting methodologies to the study of breadfruit in Hawai‘i. As a diverse subtropical location, Hawai‘i provides a useful model for extrapolating findings to other regions. The study aimed to develop allometric relationships for breadfruit wood and carbon density, tree volume, and foliar biomass. It also aimed to characterize growth curves for breadfruit and describe its above-ground carbon sequestration capabilities. This research is a step towards understanding the role of breadfruit in eco-friendly agriculture and the development of breadfruit-focused carbon projects, providing valuable data for carbon quantification efforts.