Researchers at the University of Hawai‘i at Hilo were recently awarded a Bradshaw Medal for their provocative paper questioning a fundamental assumption of the field of restoration ecology, which is the science of restoring natural habitats that have been subject to anthropogenic disturbances.
The Bradshaw Medal, named after British ecologist and restoration pioneer Tony Bradshaw, is given by the Society for Ecological Restoration, in recognition of a scientific paper published in the Society’s major journal, Restoration Ecology, which advances the field of restoration ecology.
Cordell is also an affiliate faculty member at UH Hilo who serves in an advisory role for the tropical conservation biology and environmental sciences graduate program. Coauthors Ostertag, an ecologist, and Michaud, a hydrologist, are both professors and researchers at UH Hilo. Warman is a plant ecologist with the USDA forestry institute who also teaches at UH Hilo.
A provocative approach to native forest restoration
The provocative aspect of the paper is in its relatively accepting attitude towards nonnative, noninvasive plant species, often the traditional nemesis of ecologists. The authors argue that in some cases it is better to “give up” on the traditional goal of restoring disturbed ecosystems to their pristine native state, and instead pursue a “hybrid” approach that incorporates both native plant species and nonnative (but noninvasive) plants.
“Our perspective is that in many cases we cannot keep these areas all native,” says Ostertag. “It is just not feasible or pragmatic.”
The focus of the paper is a multiyear, multistudy restoration project called Liko Nā Pilina, which in Hawaiian means roughly “growing or budding novel relationships.” The project is an ongoing effort to restore an area of Hawaiian lowland wet forest, an ecosystem found on the northeastern sides of the Hawaiian islands and that is particularly susceptible to loss of native plant species biodiversity and domination of invasive plant species. Hawaii’s native lowland wet forests were first altered by the arrival of the Polynesians and later exploited by Western colonists for agricultural and housing purposes. The result was an altered ecosystem and loss of biodiversity. Today, remnants of the forests remain on Hawai‘i Island in patchy forest reserves in Puna and East Hawai‘i, but they remain threatened by development.
In practice, ecologists want to restore ecosystems back to their original state because the native species evolved over time to fill certain niches or functions in the overall system. This was the original goal of the research team in the Liko Nā Pilina project.
“We had originally done an experiment where we removed all the invasives from our ten-by-ten meter plots,” explains Ostertag. “We thought by removing the highly invasive species we would able to improve the germination of the native species and get them to regenerate. However, that is not really what we got. And the amount of weeding we had to do to keep out the invasives was really really intense. We estimated about 40 person hours per meter squared to do all the weeding to keep it native.”
“Weeding will kill you!” agrees Michaud, the hydrologist whose primary role was studying water flow in the study area. She and Ostertag, along with rest of the team, started to realize that the ecosystem would never return to an-all native state, and even if this were possible, the cost would be too high and payoff too low.
“We realized we needed a different strategy,” Ostertag says. “Just removing the invasives, just doing a passive restoration, was not going to work, the effort was too great. We decided that we needed to do a more active restoration that involved planting the specific species we wanted. This led us to this idea of planting a hybrid forest, making hybrid ecosystems of the native and nonnative species grow together, using nonnative species that were not invasive but that could fill important functional roles. This hypothesis led us to collecting really important data that showed that one problem is that the native community is missing certain functional roles. Therefore, by including nonnative, noninvasive species that can fill these functional roles that are currently missing, we might have more success.”
An example of a functional role that can be filled by a nonnative species is providing shade.
“We found that we were missing fast-growing species with large leaves that create a lot of shade,” explains Ostertag. “We need the shade in the environment because that’s what keeps out the highly invasive seedlings. We need to manipulate the light environment to the goldilocks level where it is just right. We needed species that closed the canopy faster and helped produce shade to keep out the undesirable invasive species but that still allowed native species’ seedlings to regenerate.”
Ostertag adds that they plan to continue to manage the forest indefinitely to support the growth of native species and prohibit the spread of invasives under their new strategy of mixing native and nonnative species to fill functional roles.
“If you are in it for the long game you can start to see real changes,” she says. “After five years, we are starting to see the canopy getting darker and starting to close, and we are really reducing our weeding effort.”
Fine tuning the approach
Ostertag emphasizes that the researchers’ hybrid restoration strategy is not appropriate in every case.
“Our strategy for mixing native and nonnative is less palatable at higher elevations, which are more native-dominated,” she says. “And if there is already high native cover in an area you may not need this method. However, at the lower elevations, which are completely dominated by these highly invasive species, we think this is a realistic approach.”
Ostertag says that winning the Bradshaw Medal was a surprise considering that the team had originally written a completely different type of data-rich paper focusing on weeding and invasive species reoccurrence. The original idea was not reviewing well and instead a new paper emerged.
“We decided we would morph our study into a story format and a lessons learned paper,” says Ostertag. “It took on more of a narrative structure. I think people like the paper because we explain our experience over a decade of work, and the trials and tribulations of this lowland wet forest restoration project.”
Their mixing of native and nonnative species may raise the eyebrows of some conservation ecologists, but Ostertag says her colleagues in Hawai‘i have been very receptive to the hybrid approach.
“Ecologists who work in Hawai‘i were enthusiastic and encouraging because they understand the huge problem that we have with invasive species here,” says Ostertag. “Hawai‘i is like an endpoint on the conservation continuum. Half of our flora is nonnative, we have these highly disturbed systems in the low elevations, and if you go to most places you don’t see native species. They are completely altered, modified systems. Once people realize this, they understand that this is a potentially viable strategy that deserves to be tested.”
About the author of this story: Leah Sherwood is a graduate student in the tropical conservation biology and environmental science program at UH Hilo. She received her bachelor of science in biology and bachelor of arts in English from Boise State University.
The Society for Ecological Restoration recently presented the Bradshaw Medal to two outstanding papers published in its peer-reviewed journal, Restoration Ecology. Named for famed British ecologist and restoration pioneer Tony Bradshaw, the award honors scientific papers that advance the field of restoration ecology in a significant way. Susan Cordell, Rebecca Ostertag, Jené Michaud, and Laura Warman published “Quandaries of a decade‐long restoration experiment trying to reduce invasive species: beat them, join them, give up, or start over?” Their study investigated the most effective way to reforest native species in Hawai’i to recover biodiversity. Ostertag is a member of the Biology department and Michaud is a member of the Geology department at UH Hilo, while Cordell and Warman are affiliated with the USDA Forest Service Institute of Pacific Islands Forestry. Full article: https://www.ser.org/news/434318/
Read the article and watch the video to learn more about how UH Hilo graduate student, Jared Nishimoto, and undergraduates under the supervision of Dr. Jolene Sutton are developing genetic technologies that will help control invasive mosquitoes in Hawaiʻi.
CURE (Course-based Undergraduate Research Experiences) have proven effective for a wide-variety of student learning objectives and Matt Knope, along with his collaborators at Arizona State, are investigating which model of scientific inquiry results in better outcomes for students. Read the full article for more information.
Ms. Ashley Romero, a University of Hawai`i at Hilo Biology major,
has been awarded a $5,000 scholarship from the Fund for Education
Abroad for spring 2019. She will be participating in UH Hilo’s
direct international exchange program to the University of Waikato
in Hamilton, New Zealand.
The 22 spring 2019 FEA scholarship winners were selected from a
pool of over 1,250 applicants representing approximately 470
colleges and universities across the country.
Romero was also awarded the prestigious Benjamin A. Gilman
International Scholarship in the amount of $5,000 to be used
toward her study abroad program. The Gilman Scholarship supports
American undergraduate students of limited financial means to
study or intern abroad.
Dr. Jonathan B. Koch, a David H. Smith Postdoctoral Fellow and Adjunct Assistant Professor at UH Hilo is the lead author of two articles published in the journals PLoS ONE and Annals of the Entomological Society of America. In the journal PLoS ONE, Dr. Koch published “Phylogeny and population genetic analyses reveals cryptic speciation in the Bombus fervidus species complex (Hymenoptera: Apidae).” Cryptic speciation is the process in which organisms share a nearly identical phenotype but belong to different species. In his paper, he uses microsatellite and mitochondrial DNA data to elucidate the evolutionary history of bumble bees in the B. fervidus species complex. He discovers that the complex is made up of two monophyletic lineages that are comprised of bumble bees that have converged on color phenotypes. His research has broad implications to the conservation and management of these North American bumble bee species.
In the journal Annals of the Entomological Society of America, he published “A preliminary assessment of bumble bee (Hymenoptera: Apidae) habitat suitability across protected and unprotected areas in the Philippines”. In this paper, he constructs habitat suitability models of two bumble bee species that live the Philippines, Bombus flavescens and B. irisanensis. He discovers that their habitat is broadly distributed in the Philippines, but is threatened with deforestation. Both articles are open access, and can be downloaded from https://hilo.hawaii.edu/go/3Z and https://hilo.hawaii.edu/go/41. Dr. Koch, the Principal Investigator of the nalo meli ‘āpa‘akuma project, explores useful ways to use genomic data to guide the management and conservation of endemic Hawaiian bees.
UH Hilo Assistant Professor Jolene Sutton along with colleagues from University of Otago (New Zealand), University of Sydney (Australia), and San Diego Zoo Global have been awarded a Marsden Fund for their project, “Resolving the genomic architecture of hatching failure to improve conservation of endangered birds”. The award will provide 933,000$NZD (~630,000$USD) over three years.
Abstract: “Egg-hatching failure is a frustrating reality in endangered bird conservation. Many eggs fail to hatch due to reduced fitness of individuals with related parents (inbreeding depression). Despite decades of research on the topic, management guidelines often simply state “avoid inbreeding”. We need to do better. We take advantage of recent advances in molecular genetics and bioinformatics to discover the genomic architecture of hatching failure in two iconic endangered birds: ‘Alalā (Hawai‘i) and Kākāpō (New Zealand). These two species are powerful model systems for uncovering the cause of hatching problems that plague many species: both species have long-term pedigree data, detailed fitness records, extensive high quality genomic resources, and large numbers of samples (including embryos that died in the egg) for analysis. We will also capitalize on a growing number of published avian reference genomes to undertake comparative analysis and enable our results to be applied more broadly. By combining massive datasets in this way, we are uniquely placed to make the most of recent molecular and analytical advances and uncover why inbreeding leads to hatching failure. Our study will make a fundamental contribution to the understanding of hatching success in birds, and offer much-needed management options for endangered species conservation.”
Assistant Professor Li Tao has received an INBRE IV Junior Investigators (JIs) Award for his project, “Structural and Functional Analysis of Centralspindlin”. The INBRE IV JIs Award will provide substantial funding for up to 3 years at $100,000/year in direct costs. The Tao’s lab will center its research on the molecular mechanism through which centralspindlin regulates cytokinesis. Abnormal cell division (mitosis) causes cancer. Understanding the mechanism of cell division and its regulation has thus become a key to finding cures for cancer. Cytokinesis is the last gate to control cell division. Cytokinesis is dominated by a motor complex, centralspindlin. However, little is known of the structure and function of centralspindlin. This project will address a significant knowledge gap on the regulation of cytokinesis. It will also provide clues for the development of new anti-cancer therapies.
In photo: The Tao Lab (2018). L-R: Li Tao, Joshua Lawcock, Chelsea Blaquera, Marilyn Yamamoto, Kathleen Shon, and Jamae Balagot.