A key to sustainable Hawaiian agricultural production resides with the endemic sandalwood species

View the project final report

Commodities

• Additional Plants: native plants, trees

Practices

• Crop Production: forest/woodlot management, forestry, nurseries, nutrient cycling
• Education and Training: extension, on-farm/ranch research, workshop, youth education
• Natural Resources/Environment: afforestation, carbon sequestration, habitat enhancement, soil stabilization
• Sustainable Communities: employment opportunities, new business opportunities, partnerships, social networks

The economic and cultural values of Hawai‘i’s endemic sandalwood (Santalum) forest tree species can motivate large-scale sustainable agriculture through a silvicultural approach to restoration. Many forests in which sandalwood was once common were converted to livestock grazing or crop production and now a majority are abandoned with uncertain futures. However, reforesting suitable areas with sandalwood for timber production and oil distillation has emerged as a viable means to keep land in sustainable agriculture and diversify Hawai‘i’s agricultural products. Sandalwood is biologically and ecologically unique as a hemiparasitic tree requiring suitable hosts to survive. Sustainable sandalwood production, therefore, will require supporting diverse forest communities. The goal of our project is to improve the survival and establishment of planted sandalwood seedlings. The objectives are 1.) to better understand resource allocation between sandalwood and potential native host species and 2.) to evaluate the shade tolerance of planted sandalwood seedlings among already established host trees. Seedling survival, performance, and physiology will be measured to evaluate host suitability and sandalwood shade tolerance. Project success includes stronger partnerships with collaborating producers, as well as outputs both producers and researchers can utilize, including recommendations, scientific presentations and publications, K-12 lesson plans, and community outreach events. Outcomes include better understanding why certain native plants make more suitable hosts, how sandalwood host suitability and physiology in varying environments, increased confidence of land managers in establishing and managing diverse sandalwood forests, and greater awareness, knowledge, and appreciation of native Hawaiian species among students and communities. 

The overall goal of our project is to improve the survival and establishment of outplanted native ‘iliahi seedlings in order to support sustainable production. Successful propagation and planting are essential within the production cycle. Outcomes include understanding why certain native plants make better hosts, how ‘iliahi physiology responds under varying environments, increased confidence of land managers in establishing and managing diverse ‘iliahi forests, and greater awareness, knowledge, and appreciation of native Hawaiian species among communities.

Specific objectives are:

1.) Host plant suitability: to better understand resource allocation between ‘iliahi and potential native host species

2.) Underplanting ‘iliahi: to evaluate the shade tolerance of underplanted ‘iliahi seedlings among already established host trees

For both objectives, seedling survival, growth, biomass allocation, nutrient transfer, photosynthesis, and water potential will be measured to evaluate host suitability and shade tolerance of ‘iliahi. The objectives will be met by the leadership team members within the two-year project period (see timeline), with potential to continue monitoring the planted seedlings after the project has concluded with 5 and 10-year follow up measurements.