Summary

Extreme Climatic Events (ECEs) are rare, high-impact events such as hurricanes, heat waves, and extended drought, and they are increasing in frequency and intensity across the Pacific. These extreme events are one of the most immediate threats caused by climate change, and can provide increased opportunities for invasive species to colonize and spread. Despite potentially severe consequences, however, ECEs are rarely considered in planning efforts for ecological restoration. The authors examined the impacts of ECEs on restoration projects and the degree to which they were resilient to ECEs, and they found overwhelmingly negative impacts on restoration efforts. Impacts varied across geographies, species, and within sites, highlighting the need for restoration practitioners to adopt a “portfolio approach” to increase resilience of projects to ECEs. By diversifying the sites, species, and genotypes used as well as the methods employed, managers can reduce the risk of an entire restoration project failing when an extreme event occurs.

Results

Hurricanes and severe storms were the most reported ECEs, impacting 76% of the projects examined via wind, floods, and/or waves. The severity of impacts varied substantially by project and ECEs were not uniform across the restoration site, across all restoration methods, or across species, life stages, or genotypes.  Types of impacts included mortality, community shifts, impacts to reproduction of target species, change in vegetation structure, and changes in species cover. ECEs had overwhelmingly negative impacts on restoration projects, however a few reported both positive and negative impacts or neutral/no-damage impacts. One study reported a positive impact.

Management Considerations

• Plan for ECEs by considering the potential impacts of extreme events most likely to impact your area, possibly exceeding historical events.
• To spread risk through the “portfolio approach”, consider having multiple restoration sites instead of one; place restoration sites across scales (e.g., across elevational or rainfall gradients, or across multiple years or seasons to increase the likelihood of favorable conditions), make use of topographic complexity, and use multiple species.  If possible, identify likely spatial and temporal refugia and incorporate these into project design to reduce the impacts of ECEs.
• Consider selecting a diversity of propagule sources to enhance genetic diversity and adaptive potential to climate change. For example, incorporate species with traits that are more tolerant of extreme conditions such as droughts, heatwaves, or high winds.
• Consider having a post-ECE response plan in place that includes a budget for monitoring and invasive species control. Data on impacts from ECEs can help inform future restoration designs and guide adaptive management.

Take Home Points

• ECEs can create major setbacks for restoration projects by destroying or damaging structures or sites, and by threatening restored species.
• To increase the resilience of restoration projects to ECEs, spread risk across time and space by using the portfolio approach.
• Adapting restoration projects to ECEs or post-ECE recovery may require the use of propagules whose genotypes are more tolerant or resistant to ECEs.
• To adapt to climate change, including to an increasing frequency and severity of ECEs, restoration projects will need to plan for greater uncertainty, secure increased funding for monitoring and adaptive management in response to ECEs, and anticipate setbacks and longer timeframes for success.

Summary

Knowing how major vegetation types (biomes) might shift in a landscape as the climate changes is important for conservation planning.  Investments in restoration or species recovery might best focus on areas that are less likely to change to a different biome, while sites likely to change character to a different biome might present opportunities for translocation.  To investigate the stability of Hawaiʻi’s biomes to projected changes in climate, Fortini & Jacobi first modeled the potential current distribution of four main native biomes (dry shrubland, dry forest, mesic forest & wet forest) across the Hawaiian Islands, and then projected future biome distributions using precipitation and temperature from three end of century climate scenarios downscaled to Hawaiʻi that correspond to average temperature increases of 1.7 degrees Celsius (1.8 degrees Fahrenheit), 2.5 °C (4.5 °F), and 3.3 °C (5.9 °F). Despite large differences in future climate projections, the authors found that 35% of the areas considered are projected to maintain their currently most compatible native biome.  However, some biomes with little expected change in overall extent are projected to experience large shifts in location.

Results

The area suitable to native mesic forest is projected to decrease substantially, while the area suitable to native dry shrubland is projected to expand.  Area suitable to native wet forests increase in a wet climate change scenario and decrease in the drier scenarios. The total area suitable for dry forest remains relatively stable, but shifts across the landscape due to changes from dry forests to dry shrubland that are offset by changes from mesic forest to dry forest. Under all the climate change scenarios considered, a large portion of areas that are currently most suitable to dry shrubland and wet forest are expected to remain suitable to those same biomes. The patterns generally held across all islands, however dry shrubland increases are larger for Oʻahu and Kauaʻi, mesic forest loss is smaller for Hawaiʻi Island, and areas suitable to dry forest on Maui are projected to decrease.

Management Implications

• High-confidence, native-dominated “stasis” areas were mostly wet forest.  These areas offer options for long-term conservation as they are expected to have the greatest resilience across a range of potential future climates.
• Managers of mesic forest and dry forest face the loss or shift of large areas of these forest types and may need to consider a portfolio of tools to conserve the high levels of biodiversity found within.
• A decrease in biome suitability at a location implies increased risk of mortality of native component species and opportunities for establishment of invasive species.
• A portion of the landscape (primarily coastal areas and lower elevation wet forests) is projected to be only marginally suitable for any native biome by the end of the century. These areas may be especially susceptible to biological invasions.

Take Home Points

• Despite a high level of uncertainty, climate change is expected to force large shifts in the major biomes in Hawaiʻi by the end of the century, and proactive approaches will be needed to conserve biodiversity, ecosystem services, and livelihoods associated with affected biomes.
• While this approach reveals potential large-scale shifts in biomes, factors such as substrate age, fog interception, and non-climactic factors may be important for determining vegetation patterns at finer spatial scales. Therefore, there are likely other climate change refugia or areas for “stasis” for species not identified by this study that will be important to find and protect.

Summary

The authors conducted a global meta-analysis of 186 studies dating back to 1890 which included 665 trials to assess the outcomes of conservation actions on biodiversity. They only used studies that allowed them to compare effect sizes from the rate of change under the conservation intervention to the rate of change without the intervention (i.e., that included a counterfactual). They compared effect sizes for 7 types of conservation actions including: 1) establishment and management of protected areas, 2) measures to reduce habitat loss and degradation (such as policy and restoration), sustainable use of species, 4) sustainable management of ecosystems, 5) control of pollution, 6) eradication and control of invasive alien and problematic native species (which were combined), and 7) climate change adaptation. They also compared the effect sizes of conservation interventions grouped by three different levels of ecological organization: genetic diversity, species, and ecosystems.

Results

They found that the overall impact of conservation actions are positive and significant, indicating that conservation actions often yield beneficial outcomes for biodiversity compared with the outcome in the absence of the intervention. However, more and better studies are needed for a wider range of conservation interventions and geographic regions, especially for gaps such as pollution control, climate change adaptation, the sustainable use of species, and studies on genetic diversity, as well as studies in the Global South. In two-thirds of cases, conservation actions either improved the state of biodiversity (i.e., absolute positive impacts,~45%), or at least slowed declines (relative positive impacts, ~21%). In one-fifth of the trials, biodiversity under the intervention declined more than no action (absolute relative impacts, ~21%), whereas in a smaller number of cases biodiversity improved in both the intervention and counterfactual, but the counterfactual revealed greater improvements (~12%). These cases were attributed to nontarget impacts of eradication on native species including incidental damage or mortality, or mesopredator release. Eradication and control of invasive alien species and problematic native species had a significant positive effect on biodiversity. The impacts of actions targeting different levels of ecological organization were found to be positive and significant, with the greatest effects for actions targeting species, followed by ecosystems, and then genetic diversity.

Take Home Points

• Among the 7 conservation actions tested, the eradication, control, and management of invasive alien species showed the largest positive impact on biodiversity as highlighted by the largest effect size among groupings.
• The outcomes from conservation actions on biodiversity are substantially better than no action at all in the majority of cases. However, negative impacts of conservation actions do occur, especially due to nontarget impacts.
• Although the state of biodiversity is declining across the globe (in absolute terms), conservation actions work most of the time and need to be scaled up considerably to reverse the global biodiversity crisis.

Through a cooperative agreement with the University of Hawai’i Office of the Vice President for Research and Innovation (OVPRI), the U.S. Army Garrison is responsible for ensuring compliance with the Federal Endangered Species Act on more than 50,000 acres of U.S. Army training ground on the island of Oʻahu. The ANPRO manages 90 of the 474 federally listed endangered species in Hawaiʻi, including plants, birds, land snails, and insects. These ecologically and culturally valuable species are often located in remote, mountainous terrain that can only be accessed by highly trained biologists and technicians using 4WD vehicles and helicopters. To attain the program’s goal of balancing the requirements of the Army’s training mission with its natural resource responsibilities, the ANRPO maintains nurseries and a seed bank for rare endemic species, and engages in monitoring and surveying activities, biocontrol research and deployment, eradication of invasive plant and animal species, building fencing to keep out feral pigs and goats, and hosts public volunteer workdays to foster community engagement in conservation.

The Pacific RISA team was most excited to see the highly endangered Hawaiian land snails, known as kāhuli, which through habitat loss, climate change, predator introduction, and over-collection have been disappearing at an alarming rate. There are estimated to have once been up to 750 species across the Hawaiian Islands, but 90% of them are now thought to be extinct. Our hike would take us through forests of native species (many of which are being managed by ANRPO), up to two protected snail enclosures, one managed by the Army, and the other by the State’s Division of Forestry and Wildlife (DOFAW) and Snail Extinction Prevention Program (SEPP).

We met ANRPO Conservation Manager Jane Beachy and Rare Plant Program Coordinator Tim Chambers at the ANRPO baseyard where we were briefed, equipped with weeding tools, and fitted with spiked shoes for the steep and often muddy trail. After a 45 minute drive to the trailhead in the Wai‘anae Mountains, we hiked to Kahanahāiki, where we immediately noticed biocontrol on the very pervasive and invasive strawberry guava (Psidium cattleianum), and passed a number of rodent traps and fencing designed to keep out feral goats and pigs. Tim stopped along the way to point out the extensive work ANRPO has done to reintroduce native species, including grasses, ferns, and more well-known species like koa and ʻōhiʻa. ANRPO must not only contend with extreme conditions, predators. and invasives, but also the effects of climate change, which climate models predict will result in higher temperatures and drier conditions in the Wai‘anae Mountains.

We reached the Army snail enclosure, designed to keep out a multitude of predators, and got to work weeding out invasive species throughout the enclosure. The Army snail enclosure was recently invaded by yellow crazy ants (Anoplolepis gracilipes), so the remaining snails have been removed to SEPP’s captive rearing facility.

Our next stop was the State snail enclosure, where we immediately spotted the native tree snail Achatinella mustelina, endemic to the Wai‘anae Mountains and listed as critically endangered by the IUCN Red List Ranking. The snails seem to be thriving there – we found many of them living on the underside of the leaves of the pāpala kēpau (Rockia sandwicensis) and olopua (Notolaea sandwicensis) trees.

The hike back took us along a ridgeline where we had sweeping views of the North and West shores of O‘ahu. It also took us past a very successful plot of reintroduced hāhā (Cyanea grimesiana subsp. obatae), federally listed as endangered and found only in the Wai‘anaes. The hāhā was in bloom and its floral display seemed to surprise even our guides – their enthusiasm was contagious, and we all clambered down a steep hillside to get a closer look. ANRPO collaborates with DOFAW’s Native Ecosystem Protection and Management (NEPM) program to manage this unusual lobelia.

We would like to thank Jane and Tim for sharing their time and mo‘olelo (stories) about the good, the bad, and the ugly of what it takes to restore an ecosystem, and for the incredible job they are doing of managing natural resources in the Wai‘anaes under so much uncertainty.

Army Natural Resources Program Oʻahu
https://oanrp.com/about/

Hawaii Snail Extinction Prevention Program
https://dlnr.hawaii.gov/ecosystems/sepp/

How to Help Native Snails
https://dlnr.hawaii.gov/ecosystems/sepp/howtohelp/

ANRPO and UH
https://research.hawaii.edu/noelo/anpro-and-uh/

Oʻahu Invasive Species Committee (OISC)
https://www.oahuisc.org/

Division of Forestry and Wildlife: Native Ecosystems Protection and Management, Rare Plant Program
https://dlnr.hawaii.gov/ecosystems/rare-plants/

“There are many examples—in the Pacific Islands and beyond—of how efforts to prevent and manage invasive species have resulted in more climate-resilient communities, ecosystems, and economies”, said white paper author and Pacific RISA Co-Lead Investigator Laura Brewington

Executive Order No. 14008 mandates that US federal agencies and departments develop Climate Change Adaptation Plans to enhance the nation’s resilience to climate change, but invasive species are also documented to reduce the effectiveness of climate adaptation and mitigation actions. For example, fire-tolerant invasive grasses are supercharging wildfires in many parts of the United States, including Hawaii and the US Pacific Islands, which not only threatens critical infrastructure and ecosystems, but also reduces wildland climate resilience and carbon storage capacity.  In spite of this, only eight of the 26 federal Climate Change Adaptation Plans directly reference invasive species, and just four meaningfully consider the reciprocal impact of invasive species on climate adaptation efforts.

To develop recommendations for addressing this intersection of climate and invasive species, the ISAC author team conducted a gap analysis of the US Climate Change Adaptation Plans and synthesized case studies around the impacts of invasive species on US climate resilience. The five recommendations, if implemented, would transform how invasive species are considered within federal climate change planning, programs, and policies.

“Our research confirmed what we already suspected: federal agencies have not yet actively integrated invasive species management into climate action planning, funding, and implementation—and they must take clear steps to do so in order to meet their own climate goals,” said Leigh Greenwood, TNC’s Director of Forest Pests and Pathogens programs and Chair of ISAC’s Climate Change subcommittee. “Each of the five recommendations is achievable and would help protect both people and nature from the damaging impacts of climate change.”

Download and share the full 2023 ISAC climate change white paper!

Featured image: Water hyacinth, a fast growing invasive weed that clogs waterways and flood control mechanisms in the southeastern United States. Credit: Florida Fish and Wildlife (via Flickr).

Two of Hawaiʻi’s critically endangered birds, the ʻAkikiki and the Kiwikiu, are at risk of extinction within the next four years due to the twin threats of climate change and avian malaria carried by an invasive species. Credit: Birds Not Mosquitos

What does this have to do with climate change, you might ask? The invasive southern house mosquito, introduced to Hawaiʻi hundreds of years ago, cannot reproduce in cooler temperatures like the upper elevation forests of the Hawaiian islands. But as the climate has warmed in recent decades, they have been able to persist at higher and higher locations, which puts the native forest birds at risk of extinction from avian malaria that is carried by these mosquitos. Scientists estimate that without drastic action, some of these birds will go extinct within a few years.

Before making this momentous decision, the Board heard over three hours of testimony from citizens, scientists, school children, and natural resource managers–the overwhelming majority of which was in support of the mosquito suppression program. Often emotional, many offered testimony in ʻŌlelo Hawaiʻi with stories of their relationships to the native manu (forest birds). The Pacific RISA and members of the Pacific Regional Invasive Species and Climate Change management network testified that given the dire projections for continued temperature increases in the islands, the only way to protect the birds from avian malaria is to eliminate the vector (mosquito) that carries it.

Learn more about the research behind the mosquito suppression program, or take an opportunity to explore information about these endangered birds and the public outreach materials for the program. The full hearing before the Board can be viewed here – testimony begins at approximately minute 23.

I Ola Nā Manu Nahele  –  So The Forest Birds Thrive.

Featured image: Kauaʻi Forest Bird Recovery Project

Almost 99% of Hawaiʻi’s drinking water comes from water stored underground in aquifers across the islands, and groundwater supplies are impacted by changes in both land cover and climate. The NSF funded ‘Ike Wai (knowledge of water) Project at the University of Hawaiʻi spans multiple scientific disciplines and connects researchers to better understand how future land use and climate change might change groundwater recharge, and how, this in turn would influence water management decisions.. Following the stakeholder-driven approach used in the Pacific RISA Maui Groundwater Project, we worked with the State Department of Forestry and Wildlife, the Koʻolau Watershed Partnership, the City and County of Honolulu, and the State of Hawaiʻi Department of Planning to come up with a set of possible futures of conservation, urban, and agricultural land in the most heavily utilized aquifer on Oahu: the Pearl Harbor aquifer. Pacific RISA co-lead Laura Brewington developed the future land cover scenario maps as inputs to the groundwater model, which was run by the US Geological Survey. The scenarios reflected both transit-oriented development (dense development around the projected corridor for the Honolulu light rail project) and sprawl-type development (a business-as-usual approach), in combination with varying degrees of agricultural intensification or reduction and native forest protections.

Sustainable yield estimates and resulting differences in replacement costs were estimated for the six land cover scenarios crossed with two water demand scenarios under a potentially drier future climate. The results showed that both climate and land cover change were important drivers of changes in groundwater recharge. The degree of watershed protection, through preventing the spread of high-water-use, invasive plant species, had a much stronger impact than urban development. Specifically, protecting all of the aquifer’s native forests increased sustainable yields by 7–11% (30–45 million liters per day) and substantially decreased treatment costs compared with no forest protection. Furthermore, the greatest benefits to recharge occurred in the upper elevations of the watershed, which impacted the Waipahu-Waiawa and Waimalu subaquifers most substantially.

Running this through the groundwater optimization framework, we also found that watershed protection could increase sustainable yield by 8-12 MGD, which translated into $26-40 million in annual savings in water supply costs after 50 years. Today, the Pearl Harbor aquifer area is a mix of urban areas, military zones, agricultural lands (both active and fallow post-plantation), and conservation areas. The aquifer also supports numerous culturally and ecologically important springs, which have been rapidly declining since the rise of the plantation era in the mid 1800s. Nevertheless, there are still many important areas that rely on springs, including loʻi kalo systems, wetlands, and the Sumida watercress farm who were partners in this research. Our study found that even when confronted with the impacts of climate change, native forest protection in Hawaiʻi’ can play an important role in reducing the combined effects of land-use and climate change on groundwater resources.

Resources

• Click here to visit the University of Hawaiʻi ‘Ike Wai Project page
• Bremer, L.L., Elshall, A.S., Wada, C.A., Brewington, L., Delevaux, J.M.S., El-Kadi, A.I., Voss, C.I., & Burnett, K.M. (2021). Effects of land cover and watershed protection futures on sustainable groundwater management in a heavily utilized aquifer in Hawaiʻi (USA). Hydrogeology Journal. http://dx.doi.org/10.1007/s10040-021-02310-6

Featured image: Sumida Farms and the University of Hawaiʻi ʻIke Wai team. Credit: University of Hawaiʻi

“In this assessment of the state of the Pacific environment and conservation using endorsed regional indicators, we seek to lay the groundwork for sustained monitoring that supports action and measures Pacific success as well as our shortfalls in achieving environmentally sustainable development.”

This report is the first of its kind with coverage for the entire Pacific region, and it uses regional environment indicators to assess the status, trends, and data quality and availability for the endorsed Pacific environmental priorities. It also includes an update of the State of Conservation in Oceania report produced in 2013, which was endorsed and published in 2017. Viewers can use the interactive report website to navigate through the thematic sections of the report, which include up-to-date snapshots on land and marine resources protection, biodiversity, climate change, and the built environment. Scorecards and trends evaluate and present the level to which the region was meeting, exceeding, or failing to meet the state of the environment indicators.

During a virtual panel hosted by SPREP in April, 2021, island leaders said they were excited to use the report and its resources because it gives them a way to track their country’s progress toward meeting environment and conservation goals. By comparing achievements through time, and with their neighbors, they can set better targets for the future and set policies in motion to ensure that they meet them. Under the resources page, users can download a media kit with factsheets, interactive GIFs, and charts and graphs that are included in the report. Individual country reports are also available on this page, along with core data resources and monitoring tools for the region and worldwide.

Explore SPREP’s excellent resource today.

Featured image: Conducting forest research in Papua New Guinea as part of a carbon credit program. Credit: UN REDD.

A biosecurity plan consists of inspections, facilities, and protocols for pre-border (before a shipment or a group of passengers departs), at the border (upon arrival to the new location), and post-border (after cargo and passengers have reached their destination). The RBP for Micronesia and Hawaiʻi also contains detailed risk assessments for marine, terrestrial, and freshwater ecosystems, which are critical to regional economies and sustainable livelihoods.

Left: Adult coconut rhinoceros beetle. Right: Coconut rhinoceros beetle damage to palm trees. Images courtesy of the Hawaiʻi Department of Agriculture.

The members of each jurisdiction covered in the RBP agreed that the plan should be updated every 3 years, and the RISC initiated the first update process this November in Guam. Pacific RISA PI Laura Brewington facilitated the week-long update meeting, during which time the original recommendations and action items were identified, accomplishments and progress to-date were documented, and new concerns were raised. One of the key recommendations for the update is to develop an action plan for invasive species under climate change. As regions of the Pacific warm, precipitation patterns shift, and sea levels rise, invasive species ranges are expected to change as well. For example, outbreaks of the invasive coconut rhinoceros beetle (pictured above) have been reported on Guam and Palau after extreme storm events.  High winds damage the palm trees the beetles use as a food source and breeding grounds, and sea level rise weakens palm trees along the coast, making them more vulnerable to predation by the beetle. Dr. Brewington will be working with the RISC members and others to prepare the climate change language for the RBP update, which will be finalized and released in mid-2018.

This November, East-West Center Fellows and Pacific RISA researchers Victoria Keener (third from top right) and Laura Brewington (bottom, right) worked with the Ko‘olau Mountains Watershed Partnership on Oahu Island to remove invasive species and replant endemic kawelu grass at Konahuanui, the highest region of the Ko‘olau mountain range.

In Hawai‘i, freshwater and forest resources are inextricably intertwined. Rainfall and fog drip captured by forests supply surface stream water and groundwater from the ridge to the reef, along natural geographic boundaries. For centuries, native Hawaiians practiced a system of governance and land tenure that was based on fundamental watershed units, known as the ahupua‘a. Abolition of the ahupua‘a system in favor of privately and publicly-owned lands disenfranchised many of the islands’ original inhabitants and facilitated extensive livestock grazing that would denude native forests, directly impacting water supply. By the late 19^th century, cattle, goats, and deer had almost totally destroyed large areas of forest on every inhabited island. Alarmed by dwindling water supplies, well-meaning foresters attempted to bring groundcover species from elsewhere in the world that would thrive in the eroded, hardened soils, unintentionally leading to widespread invasion of weeds, insects, and disease. Their efforts were compounded by horticulturists who populated nurseries and botanical gardens with introduced species that outcompete the specialized native Hawaiian flora. It’s not only plants and animals that threaten the islands: introduced invertebrates and diseases, like the rosy wolfsnail (Euglandina rosea, pictured below), have decimated endemic highland species archipelago-wide. Over the past two centuries, entire Hawaiian ecosystems have been replaced by invasive species that are once again putting the islands’ freshwater supply at risk. When plants like strawberry guava (Psidium catleianum) and miconia (Miconia calvescens) invade, they convert the complex forest into a simpler ecosystem structure with little to no water-absorbing understory, while using up to 25% more water than native forest plants.[1]

The rosy wolfsnail is a predatory snail that was introduced intentionally to Hawai‘i to control growing populations of the giant African snail, but also attacked the islands’ endemic tree snails, some to extinction. This shell was found at Konahuanui, in the Ko‘olau Mountains Watershed.

Hawai‘i’s changing climate exacerbates these concerns with declining rainfall, higher rates of evapotranspiration, and average annual temperature increases in the last 30 years – especially at elevations half a mile above sea level and more. Higher elevation ecosystems are already under pressure from development and land use changes that force upward range migrations by native species.[2] Currently only 10% of the watershed areas in Hawai‘i are officially protected, but land owners and members of public and private institutions have formed watershed partnerships, like the one pictured above, to preserve freshwater availability in native forests and facilitate adaptation to climate change. Because of the feedbacks present between climate change, species introductions and spread, and freshwater, the 2010 Hawai‘i Department of Land and Natural Resources (DLNR) considers upland forests and watersheds to have the greatest potential to mitigate the effects of regional climate change and promote island resilience. On Maui Island, Pacific RISA continues to coordinate with government agencies, the watershed partnerships, and the Maui Invasive Species Committee (MISC) to assist in mapping and modeling efforts at both the species level – to target areas for restoration; and the ecosystem level – to understand biodiversity patterns under future change scenarios for large-scale planning.

Find the Ko‘olau Mountains Watershed Partnership on Facebook https://www.facebook.com/pages/Koolau-Mountains-Watershed-Partnership-KMWP/114315495268556?ref=br_tf

For more information on Hawai‘i watershed management and invasive species, see:

• Hawaii Department of Land and Natural Resources (DLNR): http://dlnr.hawaii.gov/
• Hawai‘i Association of Watershed Partnerships (HAWP): http://hawp.org/
• Hawai‘i Invasive Species Committees (ISCs): http://www.hawaiiinvasivespecies.org/iscs/