Saving the ʻŌhiʻa – Hawaiʻi’s Sacred Tree

The ‘Ōhi’a Challenge is presented here as an open challenge to solicit ideas as potential solutions and encourage collaboration. Digital Makerspace members can share their ideas to get feedback and support from the crowd to advance them. Think of it as a testing ground for your idea and a place your project can live as it advances and evolves. The competitive challenge run by the Department of Interior and U.S. National Park Service is now closed. Winners are announced at: https://www.savetheohia.org/new-page

The Problem

Two newly discovered invasive fungal pathogens are killing hundreds of thousands of ʻŌhiʻa trees (Metrosideros polymorpha) on Hawaii island. This mortality is known as Rapid ʻŌhiʻa Death (ROD) and strikes at the heart of not only the Native Hawaiian people who revere the tree as part of their family, but to everyone who has ever been touched by wondrous beauty of the Hawaiian islands. The importance of ʻŌhiʻa cannot be overstated, it is the keystone native tree species, and provides food and habitat for a myriad of species found nowhere else on Earth. Initially thought to be Ceratocystis fimbriata, researchers have confirmed that these two new pathogens are not just new to Hawaii, but also new to science, and are now called Ceratocystis lukuohia and Ceratosistis huliohia.

'Ōhi'a lehua (Metrosideros polymorpha)Photo by Joy Viola, Northeastern University

Currently, the only known visual cue of infection is when a tree’s leaves suddenly turn brown, and the tree begins to die. Current detection methods are labor intensive, frequently requiring sample collection over challenging and rugged terrain, as well as lab analysis, either on or off-site. Field sampling has been limited to trees exhibiting symptoms of infection and mortality, and there is no clear methodology to identify asymptomatic trees (i.e. trees without signs of infection). Once the trees leaves begin to turn brown, it’s already too late in the infection process to save the tree or prevent spread of the infection.

This fungal pathogen can affect individual trees as well as entire forests. There is a tremendous urgency among land managers, cultural practitioners, and private citizens to halt the spread of the disease. Loss of ʻŌhiʻa would have irreparable effects on the biological diversity, hydrology, cultural traditions, and quality of life in Hawaiʻi. Monetary losses would be in the billions of dollars; cultural losses would be priceless.

The Challenge

The Saving the ‘Ōhi’a challenge is presented here as an open challenge to solicit ideas and projects as potential solutions and encourage collaboration. Digital Makerspace members can share their ideas and projects and get feedback and support from the crowd to advance them. This challenge will be launched as a competition in Fall 2018 with a $70K+ prize purse. At that time, Digital Makerspace members can choose to submit their projects separately to the competition.

The first step to containment and eventual eradication of the disease is to be able to detect to it – before it kills and before it spreads. This challenge seeks innovative tools and creative solutions to rapidly and cheaply detect the fungal species Ceratocystis lukuohia and Ceratocystis huliohia (formerly Ceratocystis fimbriata) in asymptomatic trees (i.e. trees that do not show signs of infection) as well as at the landscape scale in larger stands. We also seek tools that can detect the potential invasion transmission pathways (e.g., wind, streams, transported soil, forest products, tools, equipment, etc.) and potential reservoirs of the fungus that lead to its spread.

Most scientists who study fungal pathogens recognize that curing infected trees is difficult or near impossible, especially if the pathogen has spread across vast areas. Early detection is a critical component of all invasive species management programs, and improvements in our capacity to detect the fungus will help us contain it, and likely offer the best chance to eventually eliminate this disease.

This challenge seeks tools and solutions to address the following constraints:

1. FIELD-BASED DETECTION OF RAPID ʻŌHIʻA DEATH IN ASYMPTOMATIC TREES

The ROD fungus is an invisible killer. Its spores are microscopic, and without boring into the tree, it is currently impossible to detect the presence of the fungus. The fungus infects the tree’s interior sapwood and chokes the tree’s water transport system. Trees may be infectious but asymptomatic for over a year, yet the only visual cue of infection occurs when a tree’s canopy suddenly turns brown, and the tree begins to die. At this stage, teams are deployed to collect wood samples from the tree and submitted to a laboratory for analysis. When the leaves turn brown, it’s too late in the infection process to save the tree and/or prevent spread of the infection.

2. DETECTION OF THE FUNGUS AT THE LANDSCAPE LEVEL

Many ʻŌhiʻa trees are found in remote sites or challenging terrain (hilly and mountainous, with steep slopes, and/or thick foilage, etc.). Being able to reach such sites is difficult, and there is a need to understand the spread of the pathogen at the landscape level to allow us to focus our efforts around control and eradication. We invite low-cost solutions for rapid field-based detection of the infection in trees across challenging terrain and in stands of trees of more than five acres, and preferably up to 100 acres.

3. ENVIRONMENTAL PATHWAY IDENTIFICATION, INCLUDING PREDICTIVE ASSESSMENT

We do not fully understand how trees become infected, what are potential reservoirs for the pathogen, and how the disease spreads through the environment. Understanding the spread of the fungus is critical, yet because the fungus is not visible to the naked eye, it is impossible to visually track it along suspected invasion pathways, including wind currents, soil samples, and possibly rain.

We invite low-cost solutions to detect (and predict) the invasion pathways and the spread of the fungus in the environment, as well as solutions that would help contain or reduce the spread without harming other beneficial species.

Criteria

• SCALABILITY: This challenge seeks tools that can detect and predict the environmental pathways of the fungi, and detect the presence of the fungi in individual asymptomatic trees and/or in larger stands -- sampling upwards of 100 acres. The highest performing tools for detecting the fungi would work for small and large-scale analysis. The tools should be designed for easy adoption by the intended users, including ease of use and cost, with a clear plan for creating a product that will have a measurable impact.
• COST-EFFICACY: New or adapted technologies must improve the cost-efficacy of detection compared to currently available options for individual trees and entire forests.
  • Current costs:
    • Average lab cost per tree tested - $21.00
    • Average field costs per tree (includes instances when staff must drive and hike to remote areas to obtain tree samples) - $36.00
    • Total average cost per tree - $57.00
• IMPACT: The proposed idea will make a significant contribution in advancing the detection of the ROD fungi and their pathways of spread through dramatic improvements in efficacy, speed, efficiency, or cost.
• FEASIBILITY: Demonstrate or persuade that the proposed solution will actually work as described. The proposed solution is tangible and realistic and, noting where it sits on the technological development spectrum (from idea to deployment), the expected amount of time before the solution/tool can be used in the field. Due to the urgency of the problem, Challenge submissions that include or are closer to an existing prototype detection tool may get higher scores than submissions that are purely ideas.

• CULTURAL ACCEPTABILITY: ʻŌhiʻa trees are culturally significant trees and solutions should not harm healthy trees or otherwise harm native natural or cultural resources.
• SUSTAINABILITY: The proposed idea is environmentally, financially, and socially sustainable in both its design and tenure.

Problem Background

Two newly discovered invasive fungal pathogens Ceratocystis lukuohia and Ceratocystis huliohia (formerly Ceratocystis fimbriata), are killing hundreds of thousands of ʻŌhiʻa (Metrosideros polymorpha) on Hawaiʻi Island. First observed in 2010, these fungi are responsible for Rapid ʻŌhiʻa Death (ROD). ROD can affect individual trees and entire forests, but is only known on Hawaiʻi Island, where currently, over 100,000 acres of forests are affected. While there is widespread support for research and management to halt the spread of ROD, many unanswered questions remain. For example, we do not fully understand how trees become infected, or how the disease spreads through forests. Understanding the spread of ROD is critical, yet the difficulty of detecting the fungus presents a significant barrier.

'Ōhi'a lehua (Metrosideros polymorpha), Photo by Joy Viola, Northeastern University

A key hurdle to the effective management of ROD at all scales is the difficulty and high cost of ROD detection efforts. The fungus is invisible, making it impossible to visually track along invasion pathways, including wind currents, soil samples, and possibly rain. Trees may be infectious yet asymptomatic for over a year, and the only visual cue of infection occurs when a tree’s leaves suddenly turn brown, and the tree begins to die as the fungus chokes the tree’s vascular system. At this stage, sample teams are deployed to collect wood samples from the tree and submit these to a laboratory for analysis. This is often a costly endeavor for trees on remote sites or challenging terrain. When the tree’s leaves turn brown, it’s also too late in the infection process to save the tree and/or prevent spread of the infection. Field sampling has been limited to trees exhibiting symptoms of infection and mortality, and we have no clear methodology to identify asymptomatic trees. We also have very limited tools for detecting fungal spores in environmental pathways such as wind, water, and soil.

Efforts to aggressively manage ROD are critically important to protect Hawaiian ecosystems and cultural traditions. Strong private and public partnerships have been formed to address the threat posed by ROD, and in 2016, a multi-stakeholder strategic response plan was created to outline a unified approach to gather information and manage the disease and its impacts. This plan underscored the need to limit the spread of this fungus and “deploy technologically advanced surveillance, monitoring, and early detection approaches” to protect ecosystems and cultural traditions.

The inability of land managers to detect the ROD fungus at early stages of infection in trees and elsewhere in the environment presents a unique challenge. This challenge is compounded by the vast landscapes on which ʻŌhiʻa trees reside, including remote and often steep areas not easily accessible by foot or vehicle. To address this challenge head on, it is critically important to develop tools that enhance the detection of ROD. Such tools promise to increase our understanding of how the disease spreads and pave the way for eventual elimination of this disease from Hawaii Island before it can spread to other islands. A solution may be worth billions of dollars to the Hawaiian economy, and contribute immensely to the perpetuation of the cultural values and identity of the Native Hawaiian People.