Past Projects

Maxwell Bendes examined how root competition between breadfruit (Artocarpus altilis) and māmaki (Pipturus albidus) affected aboveground performance. The two species demonstrated different responses to below-ground competition, with mamaki responding positively and breadfruit responding negatively. Different strategies could be seen in the allocation of roots, and impacts were affected by the relative time of establishment (that is, what plant is planted first). We suggest that māmaki's response is due to a more aggressive strategy that targets resource patches, while breadfruit is unable to compete within established māmaki zones and employs an avoidance strategy for root allocation.

Sugarcane has a high association with nitrogen fixing bacteria, some of which appear to activate primarily during decomposition, causing very high rates of asymbiotic nitrogen fixation in sugarcane mulch. Furthermore, by mixing sugarcane mulch with other litters, sugarcane appears to inoculate the litter and increase nitrogen fixation in other mulches. The amount of nitrogen fixed is heavily dependent on specifics of the practices, such as the depth of mulch and how wet it is kept over time. Fine tuning these practices could result in significant (on the order of 50 kg-N/ha) nitrogen inputs to diversified farming systems, and was likely an important, if not dominant, source of nitrogen in ancient Hawaiian agricultural systems. 

Kukui was an important element to indigenous Hawaiian agroforestry and retained some of its importance throughout Hawai‘i’s history. Using current and historical remote imagery, we mapped kukui canopy on the five largest Hawaiian Islands and examined the trends over time. Kukui is still widespread through the state, being a significant component in many novel low-land forests. However, kukui is declining, having lost an average of ∼58% of total canopy cover over the last 70 years. Spatial trends suggest that kukui likely did not spread much following the large-scale shifts in Hawaiian socio-ecosystems that accompanied the arrival of colonial powers. We suggest that the footprint of kukui in Hawai‘i closely approximates the extent of indigenous agroforestry and forest alteration.

To analyze soil nutrients and further understand traditional agriculture used on Ta'ū island, samples  of soil and economic plants were taken along transects crossing through intensive agriculture infrastructure there and in the upland of Fiti’uta. Soils were examined for several nutrients observed to be present in  traditional agriculture systems throughout Polynesia. In both surveys, data suggested that Ta'ū was no exception, reflecting similar indicators as were found in other traditional Polynesian agriculture systems, besides the depletion of exchangeable calcium in the systems of Ta'ū.

Food systems are the sum of actors and interactions along the food value chain—from input supply and production of crops, livestock, fish, and other agricultural commodities to transportation, processing, retailing, wholesaling, and preparation of foods to consumption and disposal. Food systems also include the enabling policy environments and cultural norms around food. Ideal food systems would be nutrition-, health-, and safety-driven, productive and efficient (and thus able to deliver affordable food), environmentally sustainable and climate-smart, and inclusive. To realize this vision, essential relationships must be made between actors in different sectors that can work collaboratively towards shared goals and visions. Transforming Hawaiʻi’s Food Systems Together (THFST)​ is an initiative that seeks to build statewide capacity and pave the way for a more sustainable and resilient food system (THFST 2021). A core part of any such effort is understanding and strengthening social relationships and the flow of social capital (e.g., knowledge) through the system. This efforts seeks to capture and analyze the social network of actors and relationships in Hawai’i’s food system to understand the strengths, weaknesses, and opportunities

A field study evaluating the role of indigenous soil moisture conservation practices to manage soil moisture and temperature relative to N mineralization and ʻuala (Lanikeha  variety) growth and development cultivated on soil mounds was established in dual locations of Puanui having distinct climate and soil environments. Incorporated indigenous practices include rock mulch, sugarcane leaf mulch and sugarcane leaf-rock mulch combined. Contrasting control treatments comprised ʻuala grown in bare soil in the absence of any soil moisture management practice, and bare soil having weekly irrigation. Weather data collection was inclusive to detail drivers of soil moisture and temperature under the various practices.