Building on the success of past community gatherings, the University of Hawaiʻi at 惭腻苍辞补鈥檚 (CTAHR) hosted the ʻŌhiʻa Love Fest and East Hawaiʻi Master2 Gardeners plant sale at its CARES Komohana station in Hilo in January.

Originally conceived as a way to raise awareness about the devastating disease Rapid ʻŌhiʻa Death (ROD), the festival has grown into a collaboration between CTAHR and many government and community partners involved in the scientific research in the fight against ROD.

From ma uka to ma kai

The festival highlighted the interconnection between the ʻōhiʻa tree and Hawaiʻi鈥檚 environment, from ma uka to ma kai. CTAHR Educational Specialist Charlotte Godfrey-Romo explained that ʻōhiʻa makes up approximately 80% of Hawaiʻi鈥檚 native forests and is essential for recharging the island’s aquifers.

“Everything relies on ʻōhiʻa,” Godfrey-Romo said, adding that when invasive species replace them due to ROD, invasive species take over and reduce the ability of the watershed to recharge the aquifer.

Fun and community learning

The event featured interactive educational booths and a popular plant distribution from the East Hawaiʻi Master Gardeners, the 东精影业 Indigenous Cropping Systems Lab and the Ornamental Extension Program. People lined up early to take home spices, peppers, herbs and vanilla, ʻulu (breadfruit), ko (sugarcane), ʻawa (kava) and many more plants.

One guest described the atmosphere at the Komohana station as “one giant hug,” noting how the facility’s circular layout brought people together in a shared mission of conservation.

Key educational takeaways:

• Updates on ROD and how to prevent it from spreading.
• Information on how wild cattle and feral pigs and ambrosia beetles contribute to the spread of ROD.
• Steps that ranchers, farmers, hunters and lei makers can take to protect the forest.

For more information on upcoming events and tips for protecting native forests, visit the .

The University of Hawaiʻi at Mānoa launched a new educational video emphasizing community collaboration in the fight against the devastating Rapid ʻŌhiʻa Death (ROD) that threatens Hawaiʻi鈥檚 native forests. The video, “Protecting Hawaii鈥檚 Native Forests,” is .

The video features a diverse range of voices, including forest managers, biologists, hunters and Hawaiian cultural practitioners from Hawaiʻi Island. It highlights the deep relationship these individuals have with the forest and underscores the importance of mutual respect and partnership in effective conservation efforts.

Understanding the threat

Native ʻōhiʻa trees make up approximately 80% of Hawaiʻi鈥檚 native forest canopy. These forests are vital to the state’s ecosystem, playing an essential role in protecting watersheds, recharging aquifers, and preventing soil erosion and flooding. Unfortunately, the fungi responsible for ROD continue to decimate ʻōhiʻa populations across the islands. The fungi, Ceratocystis lukuohia and C. huliohia, typically enter trees through wounds or injuries.

A significant cause of these wounds is feral hoofed animals, such as wild cattle and pigs, which create entry points for the deadly fungus by stripping bark, digging up roots and gashing trees with their tusks. While other factors such as windstorms can also cause injury, the impact of feral ungulates is a manageable threat.

J.B. Friday, the extension forester with the Cooperative Extension program of 东精影业 惭ā苍辞补鈥檚 (CTAHR), emphasized the importance of proactive work.

“The knowledge that fencing and excluding hoofed animals will help us protect native forests is a real game-changer in our efforts to combat ROD,” Friday said.

Continued access to native forests

The video also clarifies that fencing initiatives are designed to protect the forest, not to restrict community or hunter access. It explains that access points at state forests are equipped with gates and stiles to ensure continued public use. It notes that while almost all state forests are open to hunting, hunting is generally not permitted in National Parks and National Wildlife Refuges, regardless of fencing.

Funding for the video was provided by the Hauʻoli Mau Loa Foundation through the work of the Coordinating Group on Invasive Pest Species. For more information about ROD and ongoing efforts to protect Hawaiʻi鈥檚 native forests, .

More than 1,300 people gathered in Hilo to celebrate and protect one of Hawaiʻi鈥檚 most treasured trees—the ʻōhiʻa lehua.

Held at the Komohana Research and Extension Center in January, the ʻŌhiʻa Love Fest blended science, culture and community action. The event is a partnership between the University of Hawaiʻi at 惭腻苍辞补鈥檚 (CTAHR), the East Hawaiʻi Master Gardeners, and the Rapid ʻŌhiʻa Death (ROD) Extension Program.

Hands-on learning

ROD experts provided vital updates on the devastating disease that has killed more than a million ʻōhiʻa on Hawaiʻi Island alone.

Participants of all ages were immersed in activities, learning practical ways to protect ʻōhiʻa through seed planting, sustainable gardening and art.

“A special mahalo to all the volunteers who facilitated the logistics with aloha and the many exhibitors and speakers. The 4-H keiki were also so proud to share about their experiences and professionally provided details with confidence beyond their years,” said Bruce Mathews, CTAHR鈥檚 Hawaiʻi County administrator.

Backyard conservation

Native garden tours and moʻolelo (stories) offered a deeper understanding of the tree鈥檚 role in Hawaiian culture.The East Hawaiʻi Master Gardeners sold ʻōhiʻa and other native plants with the hope of turning backyards into spaces of conservation.

“What a great day!” said master gardener member Laura Rieber. “By partnering with ʻŌhiʻa Love Fest, we turned our little plant sale into a community event.”

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A team of researchers from the and are leading the charge to explore the relationship between hooved animals and the spread of Rapid ʻŌhiʻa Death (ROD). Maps of hard hit districts on Hawaiʻi Island were recently released online from a collaborative study involving community, county, state and federal experts and in infecting ʻōhiʻa trees with the fatal fungus, Ceratocystis lukuohia, that cause ROD and how fencing can help prevent the spread of the disease.

According to 东精影业 researchers, the animals damage healthy trees by digging up roots and stripping off bark. The damage makes the tree more susceptible to infection by the fungal spores carried in soil or the wind.

Fence-off Hawaiʻi鈥檚 forests

Spatial data, collected using remote-sensing technology, high-resolution satellite and helicopter imagery obtained from January 2019 through January 2023, show a greater spread of ʻōhiʻa die off in unfenced areas hooved animals can access and significantly lower ʻōhiʻa mortality in forest areas where hooved animals are blocked out by fencing. The 东精影业 researchers teamed with the Department of Land and Natural Resources (DLNR), Department of Hawaiian Homelands, The Nature Conservancy, National Park Service and U.S. Fish and Wildlife Service to assess data from forested areas within H膩m膩kua to Kaʻū on Hawaiʻi Island. The project is funded by the DLNR and U.S. Department of Agriculture Forest Service.

“The surveying and monitoring of ʻōhiʻa forests remains one of our team鈥檚 top priorities,” said Brian Tucker, a ROD data specialist at 东精影业 惭腻苍辞补 through the university鈥檚 Research Corporation. “These observations help guide our research projects, forest management practices and public outreach. We noticed a trend where the forests have less mortality due to ROD when protected from feral animals, especially cattle and pigs. We love our forests and it gives us hope because there are tools available for meaningful action to minimize the most devastating effects of ROD.”

Closer-look at ROD impacts

In October 2022, high-resolution satellite imagery analysis of two equally sized areas across the fenced boundary of Hawaiʻi Volcanoes National Park showed 99% of the 3,398 suspected trees impacted by ROD were in the unfenced area.

Analysis of remote-sensing and high-resolution satellite imagery occurred collaboratively with Tucker and researchers at the 东精影业 Hilo (SDAV) laboratory, with 东精影业 Hilo student geospatial analyst Naiʻa Odachi performing much of the work. The lab specializes in geospatial technology, which is integral in obtaining aerial imagery to detect ʻōhiʻa mortality at an individual tree level.

“Remote sensing using aerial and high-resolution satellite imagery has allowed researchers to expand monitoring capabilities on Hawaiʻi Island,” said Odachi, who is pursuing a master鈥檚 in at 东精影业 Hilo. “This imagery is used to identify individual dying ʻōhiʻa trees and can be used to direct field crews for sampling and ultimately lab analysis to confirm ROD infection.”

At the 2023 Hawaiʻi Conservation Conference this summer, Odachi presented ROD investigations she conducted at 东精影业 贬颈濒辞鈥檚 SDAV and won the Outstanding Graduate Student Oral Presentation Award.

This newly published study stems from led by 东精影业 Hilo Geographer Ryan Perroy, a professor of and director of the SDAV research lab. Perroy鈥檚 team revealed significant differences in areas on Hawaiʻi Island with and without ungulates, suggesting that ungulate exclusion is an effective management tool to lessen the impacts of ROD in forested areas in Hawaiʻi.

• Related 东精影业 News story: Rapid ʻōhiʻa death linked to hoofed animals in 东精影业 Hilo research, August 17, 2021

“With ʻōhiʻa making up 80% of our remaining native forests, preventing or reducing damage from ROD and hooved animals is critical for protecting our watersheds and only source of fresh water in Hawaiʻi,” said Rob Hauff, state protection forester at Hawaiʻi DLNR Division of Forestry and Wildlife.

ROD spread outlook

ʻŌhiʻa mortality has been observed in every district on Hawaiʻi Island, with some areas showing very high rates of mortality. Outbreaks with significant ROD mortality were also reported on Kauaʻi. This collaborative study is geared toward building upon effective management strategies already in place to help protect Hawaiʻi鈥檚 remaining ʻōhiʻa, and increase native forest regeneration and restoration.

Two graduate students from the University of Hawaiʻi at Hilo joined scientists from around the world who gathered in Aotearoa New Zealand in May to share new findings on invasive alien species and their impact on biodiversity, ecological systems and food production. Olivia Jarvis and Naiʻa Odachi presented their research at the .

Both budding researchers are investigating the use of satellite imagery to map the spread of invasive species in Hawaiʻi鈥檚 native forests. For Jarvis, it鈥檚 strawberry guava pushing out native trees, and for Odachi, it鈥檚 the fungus that causes Rapid ʻŌhiʻa Death, which is killing—at an alarming rate—a culturally and environmentally important tree in Hawaiʻi.

The students鈥� mentor, Ryan Perroy, a professor of geography who specializes in aerial imagery of vast and remote native forests suffering from Rapid ʻŌhiʻa Death, accompanied the two students to the meeting. Perroy is principal investigator at the 东精影业 Hilo laboratory (SDAV), a research unit applying geospatial tools to local environmental problems in Hawaiʻi and the Pacific region.

“Being able to present at an international conference was an incredible opportunity that allowed me to share the work our lab does with a larger audience,” said Odachi. “Additionally, it was amazing to hear about ongoing research that scientists are conducting, not only in the United States but also in other countries.”

“I had the opportunity to have interesting conversations and make some meaningful connections with scientists from around the world,” Jarvis said. “I learned a lot from talks on invasive species work from other countries and found a small community of scientists there interested in how to use machine learning and species distribution modeling to answer questions about alien plant species and climate change, similar to my project.”

Multiple funding sources

Jarvis鈥檚 funding for the trip came from the Hawaiʻi Data Science Institute and through Perroy鈥檚 SDAV lab. She also received support from a National Science Foundation cybertraining award through 东精影业 惭腻苍辞补 that is being used across the 东精影业 System to create workshops and curriculum for undergraduate and graduate students to increase cyberinfrastructure skills across environmental science fields.

Conference fees and accommodations for Odachi were covered by The New Zealand Institute for Plant and Food Research. Her trip was also supported by the Hawaiʻi Department of Land and Natural Resources (DLNR) and funding through the SDAV lab. DLNR provided funding for Perroy to attend the conference, where he also presented his research on Rapid ʻŌhiʻa Death.

To read more, visit .
—By Susan Enright

Weaving, kapa making, poi pounding and wood carving were some of the fun demonstrations attendees could participate in at the 2023 Grow Hawaiian Festival on February 25. Hosted by the friends of , hundreds of people gathered at the garden in Captain Cook on Hawaiʻi Island to celebrate Hawaiian culture and natural history with a variety of activities and speakers. This event was the first the garden has held in more than three years.

The University of Hawaiʻi at 惭腻苍辞补 (CTAHR) contributed to the festival with three educational booths.

• The shared information about the two-lined spittlebug, avocado lace bug, little fire ants and methods for ʻ艒丑颈ʻ补 seed collection.
• Noa Lincoln and his students from the presented a display showcasing traditional sugarcane varieties, samples of fresh-squeezed cane juice and on traditional Hawaiian cultivators and uses of sugarcane.
• Extension forester J.B. Friday from the and education specialist Charlotte Godfrey-Romo discussed Rapid ʻ艑丑颈ʻ补 Death, a fungal pathogen presenting a major issue for Hawaiʻi鈥檚 endemic ʻ艒丑颈ʻ补 trees.

“Despite the unusually wet weather for the leeward side of the island, hundreds of festival goers enjoyed the first public event at the garden since the COVID epidemic,” said Friday.

The Grow Hawaiian Festival aims to foster public understanding, enjoyment and conservation of Hawaiʻi鈥檚 natural resources and provide a space for the appreciation of Hawaiian culture and flora.

A new aerial chainsaw device that could assist in the battle to save Hawaiʻi鈥檚 ʻōhiʻa trees from a deadly fungal pathogen is being put to the test by a geographer. Professor Ryan Perroy and his research team have developed a drone attachment capable of sampling tree branch samples for diagnostic laboratory testing and other purposes.

The device, named K奴k奴au, consists of a small rotating chainsaw with a robotic gripper claw mounted beneath a drone, and can cut and retrieve branches up to seven centimeters in diameter. The samples are collected for diagnostic testing of forest fungal pathogens, including those responsible for Rapid ʻŌhiʻa Death (ROD).

“There have been times when we detected an ʻōhiʻa tree suspected of infection with the pathogens responsible for Rapid ʻŌhiʻa Death, but because of the location, it was too dangerous or problematic to send field crews out to sample it for confirmation,” said Perroy. “K奴k奴au has the potential to help in those types of situations.”

The cutting-edge device was developed by Perroy and his team in collaboration with researchers at ETH Z眉rich, a public research university in Switzerland, the U.S. Department of Agriculture, and R&R Machining/Welding in Hilo on Hawaiʻi Island. Perroy鈥檚 research on aerial branch sampling was recently published and featured on the cover of the journal .

Project funding was provided by the U.S. Department of the Interior鈥檚 Office of Native Hawaiian Relations, the National Park Service, and Conservation X Labs. The the 3D printer used in the project.

K奴k奴au is the name of an ahupuaʻa (land subdivision) in the Hilo area, and is also a term for a type of crab, Metopograpsus thukuhar, or ʻalamihi in Hawaiian.

Critical modifications

Researchers at ETH Z眉rich had previously developed a drone attachment capable of cutting small tree branches, however, when the 东精影业 Hilo team used the device they found that the samples of twigs were often too small to detect the fungal pathogens. In July 2019, Perroy鈥檚 team collaborated with the Swiss researchers and a Hilo welding company to develop a new drone attachment equipped to saw off larger branches.

“We successfully detected the target fungal pathogen from the collected branches and found that branch diameter, leaf presence and condition, as well as wood moisture content are important factors in pathogen detection in sampled branches,” Perroy explained.

None of the smallest branch samples tested positive for C. lukuohia, while 77% of the largest diameter branch samples produced positive results. The research shows that the new branch sampler, capable of retrieving the larger branches, provides the right size for a higher rate of successful diagnostic testing.

Since 2014, researchers discovered ROD killed hundreds of thousands of mature ʻōhiʻa trees (Metrosideros polymorpha) throughout the Hawaiian Islands and continues to spread. ROD is caused by two invasive fungi, Ceratocystis huliohia and Ceratocystis lukuohia, and has the potential to irreversibly change some Native Hawaiian ecosystems.

More on 东精影业 Hilo aerial survey research

Perroy is principal investigator at the 东精影业 Hilo , a research unit applying geospatial tools to local environmental problems in Hawaiʻi and the Pacific region. His group has been working on the detection of ROD and invasive species populations over forests across Hawaiʻi using high-resolution cameras and other sensors carried by drones and helicopters. The collected images and data provide managers precious time to respond to outbreaks, and gives scientists better information on how diseases and invasive species spread.

In 2019, Perroy won $70,000 in a competition sponsored by the National Park Service for his innovative use of drones and remote sensing devices to detect ROD. Throughout the last three years, Perroy and his team have continued to hone and refine the equipment needed to conduct aerial sampling using a small unoccupied aerial system.

New findings reveal the spread of a fungal disease killing off hundreds of thousands of mature ʻōhiʻa trees (Metrosideros polymorpha) on Hawaiʻi Island could be exacerbated by the presence of ungulates or animals with hooves. A geographer at the , along with colleagues from the National Park Service, U.S. Forest Service and U.S. Department of Agriculture, published a collaborative study that closely examines .

Lead investigator of the study, Ryan Perroy, an associate professor of at 东精影业 Hilo, specializes in remote sensing and was integral in obtaining aerial imagery to detect ʻōhiʻa mortality at an individual tree level. The study鈥檚 co-authors collected field samples and conducted laboratory testing using data from impacted areas within Hawaiʻi Volcanoes National Park (HAVO) and the Laupāhoehoe Forest Reserve.

The spatial patterns of ʻōhiʻa mortality observed across all four sites included in the study show significant differences in areas with and without ungulates, suggesting that ungulate exclusion is an effective management tool to lessen the impacts of ROD in forested areas in Hawaiʻi.

“The results from this work show us that the impacts of ROD can vary across the landscape,” said Perroy. “We hope this information can be useful in managing and caring for our native forests.”

Learn more about 东精影业鈥檚 work with rapid ʻōhiʻa death

Perroy leads the 东精影业 Hilo Spatial Data Analysis & Visualization Research Laboratory alongside Timo Sullivan and Daniel Duda. They all joined forces with a Hawaiʻi Island-based research team, which includes David Benitez, an ecologist at HAVO; Flint Hughes, an ecologist at the Institute of Pacific Islands Forestry; and Lisa Keith, Eva Brill and Karma Kissinger, plant pathologists from the Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center.

The researchers discovered the number of suspected ROD trees in unfenced areas were significantly higher (more than 50 times greater for one location) than those found in fenced areas that prevent hoofed animal access.

• Related 东精影业 News story: Tracking the spread of Rapid ʻŌhiʻa Death on Kauaʻi, October 12, 2020

ROD was first discovered on Hawaiʻi Island in 2014 and has since obliterated hundreds of acres of once sprawling ʻōhiʻa. It is also found on Kauaʻi, Maui and Oʻahu. The deadly disease is caused by two invasive fungi, Ceratocystis huliohia and Ceratocystis lukuohia, and, if left unstopped, could irreversibly change Hawaiian ecosystems and cultural traditions by diminishing the keystone native tree in Hawaiian forests.

Study enhances ROD data collection

Based on collected aerial imagery, the researchers developed a rating system based on tree canopy condition to identify ʻōhiʻa that may be infected. They developed a custom imaging system for helicopter mapping operations, which enables a much wider surveying scale.

Using this system, the researchers quickly generate and share suspect tree candidate locations with partner agencies to rapidly detect new mortality outbreaks and prioritize field sampling efforts. The studies revealed disparities between sites, illustrating challenges to definitively determine the cause of ʻōhiʻa mortality from aerial imagery alone. The integrated approach of imagery, field sampling and lab work proved better at effectively discerning causative factors.

This research identifies effective strategies for HAVO and other protected areas, where study co-author Benitez considers ROD to be a top threat to native forests and ecosystems. “The focal sites include forests near the summit of Kīlauea, including Nāhuku and the ʻŌlaʻa Tract rainforests and the Kahuku Unit,” Benitez explained. “We are very excited about this collaborative research, and the resulting technologies such as a safer and more cost effective airborne mapping system which can pinpoint ROD outbreaks across vast areas on all Hawaiian Islands.”

Need for feral animal control

An unexpected event at one of the study sites showed the impact feral pigs caused after they breached a fenced area. Suspect ROD tree densities in the area rose from practically none to nearly three trees per hectare (nearly 2.5 acres) highlighting the need for ungulate control.

“There are lots of remaining questions that still need to be addressed relating to ungulate species-specific behavior and impacts (pigs vs. goats vs sheep vs. cattle), differences between domesticated and feral animals, and lots of remaining questions regarding non-ungulate factors we think play a role in ʻōhiʻa mortality, from boring beetles to storm events,” said Perroy.

The paper also illustrates the importance of removing infected trees to suppress ʻōhiʻa mortality levels across affected regions.

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—Story by Susan Enright

All things ʻōhiʻa lehua, the most abundant tree in Hawaiʻi鈥檚 native forest, will be celebrated during the , which runs Monday, November 16鈥揝aturday, November 21, 2020. The week-long virtual festival pays homage to ʻōhiʻa lehua trees, which are important to Native Hawaiian culture, and critical to recharging 贬补飞补颈ʻ颈鈥檚 aquifers and protecting our nearshore reefs. The festival also raises awareness about preventing the spread of Rapid ʻŌhiʻa Death (ROD) disease.

The 4th annual event is free and open to the public, and will feature online workshops on ʻōhiʻa seed sowing, identification and seed banking, hands-on demonstrations, keiki activities, music, ʻōhiʻa themed keiki books storytelling, screening of the documentary , a pre-recorded field trip of a day in the life of an ʻōhiʻa field crew, and a Bishop Museum herbarium and ethnology collection video with live panel discussion. Registration for events is available .

Starting on November 2, a free keiki crafts kit, which includes a coloring book, field guide, crafts and a sticker, is available while supplies last. The keiki kits can be picked up at the Hilo Public Library, Wailuku Public Library, Hawaiʻi State Library, Hanapepe Public Library, Kapaʻa Public Library, K艒loa Public and School Library, 尝墨丑耻ʻ别 Public Library, Princeville Public Library and Waimea Public Library.

“This event has usually been held on Hawaiʻi Island, but since it is virtual we can expand to a statewide, national and international level, and this is important because we have found ROD on Hawaiʻi Island, Kauaʻi, Oʻahu and Maui,” said Ambyr Mokiao-Lee, University of Hawaiʻi at 惭腻苍辞补 (CTAHR) festival coordinator and ROD statewide outreach coordinator. “Although we have found this disease on these islands, the vast majority of these forests are still healthy and we are working to protect them for future generations.”

The festival is hosted by the ROD program of 东精影业鈥檚 CTAHR Cooperative Extension Service. Other festival support comes from the state Department of Land and Natural Resources, local invasive species committees, Hawaiʻi Tourism, and the Omidyar ʻOhana Fund of the Hawaiʻi Community Foundation.

Visit the for a schedule of events, and visit or for updates.

Researchers at the University of Hawaiʻi (PCSU) have collaborated with multiple agencies to develop a management tracking system to keep crucial data organized as the (ROD) fungus continues to spread to parts of Kauaʻi. The system allows field staff to compile data from multiple sources into one place, facilitate planning of management and research activities, and provide progress updates.

“Supporting the work on Kauaʻi is one of my highest priorities,” said Brian Tucker, PCSU ROD data manager, who supports all aspects of statewide management planning, field implementation and reporting. “Electronic data collection in the field and geospatial data management enable field staff on Kauaʻi to track outbreaks and new discoveries of ROD.”

• Read more about ROD on 东精影业 News.

The compiled data begins with suspect ROD trees, or trees that have recently died and exhibit ROD symptoms. Data is mostly compiled through aerial surveys via helicopter or drone, but also includes ground reporting by landowners.

Suspect ROD trees are then entered into the database, where they are prioritized based upon multiple criteria of location and accessibility. These suspects then may be visited for sampling and other research activities. Observations are made and entered into the database during visits and re-visits. The tracking system allows multiple agencies to know what has been completed, and when. Over time, the data will show how the disease has grown and spread.

To date, there have been a total of 181 confirmed ROD cases on Kauaʻi, which includes 101 Ceratocystis lukuohia, the more aggressive and devastating species. There have been 78 Ceratocystis huliohia fungus infected species. Two of the confirmed cases were co-infected with both species.

Mitigation efforts

Monitoring of forests began prior to ROD being discovered on Kauaʻi when the first samples of dead ʻōhiʻa were collected in February 2016. While ROD was not detected, the Hawaiʻi Department of Land and Natural Resources began doing aerial surveys to locate ROD suspects in June 2016. Mitigation efforts began immediately after ROD was first discovered on Kauaʻi in May 2018.