*3.5. Ecological Health*

Contemporary 'ulu farmers demonstrate the ability to cultivate breadfruit in a way that protects the environment while remaining profitable. The majority of breadfruit farmers do not use fertilizers, herbicides, or irrigation, with a mere 7% of growers using pesticides (Table 2). Among the users of chemical and water inputs, only two had regular schedules, while the majority of growers applied fertilizers rarely with application times based on tree observations.

**Table 2.** Rates of various management practices associated with breadfruit cultivation among survey participants.


As mentioned previously, most 'ulu farmers surveyed intercropped their breadfruit trees. The diversification of crops in agroforestry systems increases the value of production, enhances profitability of traditional farms and reduces production costs due to a decreased need for inputs such as water, chemicals and energy [56]. Despite low inputs, farmers reported a 97% average success rate for all sapling establishment on average. When farmers added care to their trees, they largely chose environmentally friendly inputs such as recycled or green waste materials for mulch (e.g., clippings, woodchips, leaves, cardboard), organic or homemade fertilizers (e.g., fish emulsion, chicken manure) and natural compost (food scraps, mixed garden waste, human waste from composting toilets). "Farmer C" farmed without chemical inputs and only organic material as fertilizer yet reported exceptionally high yields. "Farmer H," utilized no inputs, also reported high yields and her tree's measurements showed the highest rates of photosynthesis of any producer measured. That breadfruit is highly productive without excessive inputs is captured by agricultural producer, "Farmer L," who said of his trees,

"Is it a superfood?! It's definitely a tree of abundance. I always joke around it's like a tree of life. Hundreds of pounds. With really minimal [inputs], I fertilize them once in a while but other than that they just go. It's definitely a tree that gives plenty. It's suited for here. I learned to not quite force anything. There's so many trees I've tried to make grow on a farm. It's the ones from here that can endure."

While we did not investigate the role of biodiversity, several farmers made mention of their breadfruit trees being home to the 'io (the Hawaiian hawk, *Buteo solitarius*) and the 'ope'ape'a ¯ (the Hawaiian hoary bat, *Lasiurus cinereus semotus*), an iconic, endemic and federally endangered species. While this is not an adequate proxy for biodiversity, the presence of these two rare animals nesting within breadfruit agroforestry clearly establishes the potential of increased habitat. Preserving biodiversity is an important concept for biocultural restoration, especially in agricultural development where the loss of biodiversity and environmental destruction are attributed to conventional agriculture methods such as monocropping [4].

Ultimately, breadfruit cultivation provides multiple environmental benefits under current production practices. Tree crops in general have shown to have multiple benefits and those impacts are enhanced in agroforestry settings. Forests are valuable systems needed to carry out ecosystem services essential to sustain the natural resource needs of society [5]. Agroforestry has the ability to replenish litter layer to the soil, increase and maintains soil quality, retain soil nutrients and prevent soil erosion [56,57]. For example, growers had, on average, very high levels of soil organic matter (mean 15.25%, standard error 1.38). These same functions improve water filtration and retention rates, increase water availability, reduce runoff and evapotranspiration, collectively improving water quality [56,57]. The shade and presence of multiple tree species also provide habitat, wind protection and essential microclimates that assure cooler summers and warmer winters [57]. The incorporation of increased biodiversity into farming systems at different trophic levels increases crop yields, wood production, yield stability, presence of natural pollinators and encourages weed and pest suppression [58]. The combination of low inputs, low labor, high productivity and ecosystem services benefits showcase the importance of breadfruit as a sustainable crop.

#### **4. Conclusions**

Breadfruit holds a unique position in the concept of biocultural restoration in Hawai'i by contributing to the five key themes described above. As a productive, low maintenance crop, 'ulu has the ability to be grown sustainably, which offers the dual role of food production and ecosystem restoration. Increasing availability of healthy foods in the market and through food sharing contributes to greater food security. The continued cultivation of breadfruit is reliant on the continuation of biocultural relationships, or passing knowledge on its growing needs and its importance as a food. Through these cycles, the cultivation of breadfruit in Hawai'i is supported by Hawaiian culture and Hawaiian culture is supported through breadfruit cultivation, where the restoration of one can affect the other (Figure 2).

Although we presented some of the key findings organized within reoccurring themes, these themes clearly overlap and interact with each other. The revival of customary values, for instance, brings forward practices that contribute to the development of community capital, which in turn provides direct benefits to food security through multiple direct and indirect effects. These interactive effects demonstrate, among other things, the intertwined nature of biocultural systems, in which the growth of one necessitates and requires the growth of the other. In multiple examples, we see both the positive and negative reinforcement that occurs within these systems. In a destructive loop, "Farmer F" was not able to receive cultural knowledge regarding breadfruit because the tree itself was not present in his mentors' lives. Conversely, through growing the tree he has recognized how it has contributed to the growth of his culture and identity within himself. As breadfruit cultivation continues to expand its inseverable connection to the Hawaiian culture will continue to fuel the growth of associated value systems. Scaling up, there is evidence that relatively small farms that practice diversified agriculture could increase food production globally, while simultaneously addressing sustainability issues regionally. Referring to Figure 2, traditional agriculture in Hawai'i is a major mediator between biological and cultural components and at the intersection of the three concepts of sustainability. This is where agriculture is significant in regard to sustainable socioecological systems. Breadfruit cultivation through traditional agriculture methods supports the needs of sustainable agriculture and can provide valuable ecosystem services while simultaneously producing food. From the social and cultural side, breadfruit is present in traditional practices that are necessary to sustain its cultivation long term.

Our findings suggest the support of breadfruit production has the potential to be a pivotal solution to sustainability issues in Hawai'i. Evaluating the experiences and lessons learned from discussions with farmers, we saw that breadfruit is making significant contributions to reconnecting people with place, revitalizing traditional agriculture and Hawaiian culture and that this phenomenon has practical implications for the future. While we cannot say if breadfruit itself promotes these activities or if individuals who engage in these practices are more prone to grow breadfruit, the biocultural restoration of breadfruit can be strongly linked to the furthering of a sustainable socioecological system regardless.

As stated by "Farmer H,"

"We have started calling breadfruit a 'solutionary' food. There are so many problems with our food system. I mean there is the health and nutrition, there are the environmental issues, there is food justice and food security. And there is just the loss of identity and enjoyment of food. So many issues that need to be fixed. We need a revolution of the way we deal with food. What is amazing about breadfruit is that it hits all of these. I mean, more than any other food I can think of. That it is a tree. That it is embedded in the culture. That it is a nutritious staple. It really has the potential to be a solution to many problems in our food system. So, it is the revolutionary solution that we need...'solutionary.' Get it?"

**Author Contributions:** Conceptualization, N.L.; Methodology, N.L.; Software, N.L.; Validation, N.L., B.L.; Formal Analysis, B.L., N.L.; Investigation, B.L., N.L.; Resources, N.L.; Data Curation, B.L., N.L.; Writing-Original Draft Preparation, B.L.; Writing-Review & Editing, N.L., B.L.; Visualization, B.L., N.L.; Supervision, N.L., B.L.; Project Administration, N.L., B.L.; Funding Acquisition, N.L.

**Funding:** This research was funded by the USDA Western SARE project, grant number SW17-050 and the USDA National Institute of Food and Agriculture, Hatch project HAW08035 administered by the College of Tropical Agriculture and Human Resources. The APC was funded by Hawai'i Community Foundation.

**Acknowledgments:** We would like to acknowledge all who offered their time, support and knowledge. This includes the breadfruit farmers who participated in the interviews, staff, interns and volunteers who helped with data collection, input, travel, sample collection, storage and processing including; Amber Au, Kat Hiu, Kimber Troumbley and Maxwell Bendes. We would like to thank the Hawai'i 'Ulu Producers Cooperative for connecting us with local 'ulu farmers. Thank you to Matthew Lucas for technical Geographic Information Systems Assistance. Thank you to friends and colleagues who edited and revised; Maxwell Bendes, Kalisi Mausio, Amber Au and Kawika Winter.

**Conflicts of Interest:** The authors declare no conflict of interest.

### **Appendix A**

**Table A1.** List of survey question reported on in this paper as administered to 43 successful breadfruit cultivators in Hawai'i.


**Table A2.** List of general interview topics that were explored with willing participants.
