Weed Meeting Archives | Ecosystems Work

Weed Management Meeting
Archives

This page archives knowledge exchanges between natural resource management programs, projects and research. The Big Island and Maui Nui Natural Areas Weed Management Forum were facilitated by J. Leary from 2015-2018. While largely focusing on Weed Management, there are select restoration focused presentations.

The Oʻahu Weed Control and Restoration Workshop was initiated by the "Oʻahu Weed Working Group" (est. 2011), which later changed its name to Priority Oʻahu Native Ecosystems (Priority ONE) working group to better address restoration topics alongside weed control ones. The 2015-2020 (and 2022) workshops are included in this archive.

We are in the process of acquiring permission to provide access to presentation PDFs through this page. If you see a presentation that you gave, either with missing permissions or missing a pdf for the presentation, let's chat! You also may notice some presenters highlighted in yellow--we are looking for their affiliation at the time of the presentation. Thanks for connecting us to that information!

In 2023 we (slowly) started to reconnect folks in county-level meetings. Search "weeds" in the search bar for more information. Want a meeting on your island?! Let's chat! You can reach us at EcosystemsExtensionHI@gmail.com

Natural Areas Weed Management & Weed Control and Restoration Forums

2017

Big Island Natural Areas Weed Management Forum

A Phased Approach to Improving Habitat for a Critically Endangered Species

Steve Evans & Pamela Sullivan

Natural Resources Office, Pōhakuloa Training Area, Center for Environmental Management of Military Lands, Colorado State University

The PTA NRO manages 4 listed plant species in the Keʻāmuku Maneuver Area. One is Melanthera venosa, a federally endangered, low-growing, perennial herb. It is restricted to Hawaiʻi Island puʻu in montane dry shrublands dominated by invasive grasses, at elevations from 725 to 1136 m. The species numbered approximately 4,150 individuals in the 1980's and occurred on as many as 6 puʻu. The distribution has been reduced to potentially just 1 puʻu (Nohona o Hae) with less than 100 individuals due to continued habitat degradation. Although Puʻu Nohona o Hae had been fenced and ungulates removed, M. venosa continued to decline due to increasing densities of invasive species such as Cenchrus setaceus. However, care needed to be taken to ensure that removal of C. setaceus did not negatively affect M. venosa by altering the biotic and abiotic conditions or impacting common native species. Therefore, PTA NRO implemented a tiered weed control strategy that will be followed with habitat improvement. Weed control was phased in to gradually alter conditions and allow M. venosa to acclimate. C. setaceus was gradually reduced to 1 foot and killed within 1 m of M. venosa, and cut to the ground and treated with herbicide within a 25 m buffer. Unfortunately, weed control around M. venosa coincided with a dry period and plants seemed stressed as a result, necessitating additional management. Subsequently, weed control revealed a high density of native species previously over-topped by C. setaceus throughout the weed control buffer. Going forward, the site will be monitored for natural recovery of common native species. If needed, outplanting of the less common natives will be considered, and finally augmentation of M. venosa may occur. This effort highlighted the need for a true, adaptive management approach, rather than management by trial and error, to improve management outcomes.

2017

Big Island Natural Areas Weed Management Forum

An Overview of the HVNP Alien Plant Control Program

David M. Benitez

Hawaiʻi Volcanoes National Park – Pacific Islands Exotic Plant Management Team

The National Park Service (NPS) is mandated to protect natural resources for future generations, and alien plant invasions present a direct threat to this mission. HVNP’s alien plant control program has expanded significantly over the past 30 years, from less than 200 to over 1,200 worker days in the field, and includes over 134 species controlled or monitored for invasiveness. Of these, at least 33 are widespread, highly disruptive species, many ranked among the world’s worst invaders. Strategic management of weeds is imperative since resources to fund operations are limited, many species are widespread, new species continue to establish, and changing climate presents long term uncertainties. HVNP’s weed management strategy is grouped into two different approaches, depending on the distribution of the target. A localized approach is employed for species with discrete populations of few individuals or a limited extent, and a Special Ecological Area (SEA) approach is employed to exclude more widespread species from high priority areas if they cannot be controlled park-wide. The high priority areas are selected based on attributes including representativeness, manageability, and value for research and interpretation. In fiscal year 2016, 1,287 worker days were spent in the field controlling invasive weeds. Staff, partners, and volunteers controlled 92,157 plants of 72 species, and 60.7 acres invasive grasses, blackberry, and ginger. NPS and cooperator crews systematically swept 25 blocks in 11 SEA units in the park. Volunteers in Parks (VIP’s) contributed 20% of program field workloads (261 worker days), and youth programs and youth volunteers contributed 17% of program field workloads (214 worker days). The high productivity of the park’s alien plant control team is a product of a sustained long term commitment and highly experienced staff, intolerance of unsafe work practices, highly leveraged workforce including partners and volunteers, and organizational support from NPS and other agencies.

2017

Big Island Natural Areas Weed Management Forum

Assessing the Detection of Miconia with sUAS

Ryan L. Perroy, Nathan Stephenson, Timo Sullivan, & Caley Saragosa

University of Hawaiʻi, Hilo

Small unmanned aerial systems (sUAS) can facilitate the early detection and management of invasive plants, even in the understory of dense tropical forests. Here we show how overstory vegetation cover (canopy openness), imagery resolution, and camera look-angle impact the aerial detection of known individual miconia (Miconia calvescens) plants using sUAS. For our finest resolution imagery (1.37 cm ground sampling distance collected at 30 m agl), we obtained a 100% detection rate for sub-canopy plants with above-crown openness values >40% and a 69% detection rate for those with >20% openness. We were unable to detect any plants with

2017

Big Island Natural Areas Weed Management Forum

Biology and Management of Incipient Miconia in the East Maui Watershed

Leary, J., K. Burnett , C. Wada, R. Rodriguez, D. Jenkins & B. Mahnken

Dept. of Natural Resources and Environmental Management, UH Economic Research Organization, Dept. of Molecular Biosciences and Bioengineering, Maui Invasive Species Committee

Miconia (Miconia calvescens DC) was introduced to East Maui as a single horticultural specimen circa 1970. Management commenced two decades later with a 25-year history that continues today. In 2012, Herbicide Ballistic Technology (HBT) was introduced as a novel treatment platform on manned helicopter surveillance missions; virtually doubling operational efficiency by combining intelligence gathering activities with concurrent target elimination. To date, over 100 HBT missions have been conducted, approaching 500 hours of operational flight time, treating over 20,000 high-value incipient targets, protecting over 18,000 ha of the East Maui Watershed (EMW). These robust operations data allow us to explore performance analytics in a real management setting, e.g., search efficiency, herbicide use rate, etc., which can be further monetized to determine variable costs of an operation. With basic GIS, we have also determined the dispersal kernel of miconia in the EMW, spreading out to 1644 m from the maternal source, creating an impact area approaching 850 ha. Our future goal is to use these new model parameters for optimizing containment strategies with most effective impact reduction and highest return on future cost avoidance. The aerial deployment of HBT is proving to be an efficient management system reducing further impact to these fragile ecosystems. To conclude, the successful adoption of this new technology was achieved through a spontaneous form of participatory action research where scientists and practitioners shared in the responsibilities of research and management towards evolving solutions in sustainable invasive species management.

2017

Big Island Natural Areas Weed Management Forum

Cheap, effective control of Albizia: Yes, it can and should be done

Flint Hughes, Travis Sowards, Kyson Dunn, Springer Kaye, Caitlin Morrison, Angalee Kirby, & Bill Buckley

USDA Forest Service, Big Island Invasive Species Committee

Hurricane Iselle struck Hawaii Island on August 7, 2014 as the third strongest storm to impact Hawaii since 1950, exhibiting sustained winds of 80 m.p.h., and gusts greater than 110 m.p.h. Cost estimates of damage from Iselle reached beyond $10 million; the bulk of the damage was caused by trees felled by Iselle’s high winds; which overwhelmingly consisted of 100 to 130 ft. tall stands of the highly invasive, fast-growing Falcataria moluccana (a.k.a. Albizia). As a result, Hawaii’s residents, national, state, and county legislators, governmental agencies, and public and private utility companies galvanized around a strategy to eliminate stands of Albizia that may currently, or in the future, pose threats to public health and welfare. At its core, this strategy will remove hazard trees using the most economical and effective means available, and will kill non-hazard trees using herbicide applications that are highly successful and cost effective. Here we report results from investigations to evaluate and inform the effectiveness of combined Albizia control approaches. Beginning in March 2015, a total of five study sites were set up to monitor compositional, structural, and functional dynamics of albizia stands following treatment with the highly effective Milestone herbicide. Study sites were located across 3 different volcanoes and three distinct soil types on soils ranging in age from 200 to 75,000 years and at elevations ranging from 28 to 378 m above sea level. Pairs of 0.5 ha monitoring plots were established at each study site; in one plot of each pair (i.e., the treatment plot) – all albizia trees were killed by treating them with Milestone herbicide. In the other plot of the pair (i.e., the control plot), albizia trees were not treated with herbicide. Results are presented and discussed; overall, they clearly demonstrate the efficacy of the management approaches.

2017

Big Island Natural Areas Weed Management Forum

Cultural Landscape Rehabilitation Through Restoration of Native Ecosystems

Jackson Letchworth, Tyler Paikuli-Campbell, & Sallie Beavers

Kaloko-Honokōhau National Historical Park

Kaloko-Honokōhau National Historical Park preserves coastal areas of five ahupua’a in the North Kona District, Hawaiʻi Island. Large-scale invasive vegetation removal projects focusing on red mangrove (Rhizophora mangle), kiawe (Prosopis pallida), fountain grass (Cenchrus setaceus), and Christmas berry (Schinus terebinthifolius) were initiated in the Park in the 1990s. Currently, in addition to ongoing restoration of native dryland shrub forest, two large scale projects are underway to restore coastal wetlands associated with two Hawaiian fishponds. Restoration in a site rich with cultural sites and features poses multiple challenges. A variety of approaches to labor and methods are utilized in all restoration efforts, including national park staff, independent contractors, and community stewards applying both manual and mechanical methods for removal, and helicopter hauling for disposal. These dynamic restoration projects work in unison towards the rehabilitation of the cultural landscape and help support the Park’s mission to preserve, interpret and perpetuate traditional native Hawaiian activities and culture, and demonstrate historic land use patterns.

2017

Big Island Natural Areas Weed Management Forum

Estimating and applying biological parameters to enhance management of Rauvolfia vomitoria, an invasive tree in North Kohala, Hawaiʻi

Timo Sullivan

University of Hawaiʻi Hilo, Kohala Watershed Partnership, Hauʻoli Mau Loa Foundation, Big Island Invasive Species Committee

Estimating and applying biological parameters to examine and enhance management of Rauvolfia vomitoria, an invasive tree in North Kohala, Hawai'i. At times, managers may plan to either contain an invasive population within—or exclude an invasive species from—a certain area. Given that neither strategy addresses the invasive source population, both will require similar, and perpetual management inputs over time to maintain their success. These inputs involve the detection and removal of immigrants from the source population either into the area of exclusion, or beyond the area of containment. Large-scale detection and removal efforts of invasive populations can be costly, and because of the perpetual nature of these strategies, costs can accumulate to significant levels. Consequently, managers practicing either strategy can either minimize or exaggerate these costs in relation to how well calibrated their management actions are to the invasive species’ characteristics. In order to successfully deal with the threat of invasive immigrants entering the zone of exclusion or leaving the zone of containment, managers must understand (1) how far these immigrants can disperse from the source population into the managed area, and (2) how quickly these immigrants can reach mature status and become an encroached source population. By understanding these phenomenon, managers can then better estimate the necessary buffer size and frequency of management input to ensure that all source populations immigrants are detected and controlled before generative status. By gathering simple growth and dispersal vector behavior data, I was able to create these types of estimates for buffer size and management frequency in regard to the invasive tree species R. vomitoria, currently found in the North Kohala region of Hawaiʻi island. Additionally, different tiers of predictive interval confidences—e.g., 95%, and 99.9%—were created through general linear modeling. This allowed multiple management scenarios to be compared regarding how these different confidences can affect management strategies and cumulative costs over time, e.g., management input every 4 or 5 years.

2017

Big Island Natural Areas Weed Management Forum

Getting Into the Weeds: A Summary of Invasive Plants in Hawaiʻi’s National Parks

Jacob Gross & Alison Ainsworth

National Park Service, Inventory & Monitoring Program, Pacific Island Network

The Pacific Islands Network Inventory and Monitoring (I&M) program monitors non-native plants within relatively intact plant communities across national parks of Hawaiʻi, American Samoa, Guam, and Saipan. Monitoring occurs every five years per park. Results from the first cycle of monitoring (2010-2013) at Hawaiʻi Volcanoes (HAVO) and Haleakalā (HALE) national parks include richness, frequency, and cover of non-native life forms and plant species at various spatial scales. Non-native plant species were documented within the wet forest and subalpine shrubland plant communities of HAVO (18,000 ha) and HALE (7,000 ha). Nearly twice as many non-native species were recorded in HAVO (108) as compared to HALE (60). However, the subalpine shrubland at HALE contained greater frequency and cover of non-native plants. Species richness, frequency, and cover were best summarized at small-scale, contiguous sampling frames rather than by plant community. Sampling frames were generally distinct in non-native species composition, likely a result of different microclimates, disturbances, adjacent land use, and accessibility. Non-native plants within HALE’s wet forest show a trend of decreasing cover with increasing elevation. Two of the most frequent invasive plants in HALE’s wet forest, Clidemia hirta and Hedychium gardnerianum, were only found as incipient populations during previous monitoring in 1988. At HAVO, five new park and two new island species were found during monitoring efforts. Continued monitoring in these areas will increase spatial coverage and allow for change detection, helping managers to prioritize existing and emerging threats.

2017

Big Island Natural Areas Weed Management Forum

Invasive Plant Management within UH Managed Lands on Mauna Kea

Darcy Yogi

OMKM Natural Resources

The Office of Maunakea Management (OMKM) manages over 12,000 acres at high elevation on Maunakea including the Mauna Kea Science Reserve (MKSR), summit access road, and Halepōhaku mid-level support facilities. UH Manged Lands on Maunakea contain three ecological zones: (1) the alpine stone desert (3400-4200 m), (2) alpine shrubland (2900-3400 m), and (3) subalpine māmane woodland (below 2900 m). High elevation plants on Maunakea must be able to withstand the low temperatures, low precipitation, high radiation, and little to no soil. This harsh environment restricts many of the prolific invasive plant species at lower elevations. Common invasive plants within UH managed lands include fireweed (Senecio madagascariensis), mullein (Verbascum thapsus), gosmore (Hypochaeris radicata), Chilean evening primrose (Oenothera stricta), needlegrass (Nassella cernua), and sheep sorrel (Rumex acetosella). Early detection targets include fountain grass (Chenchrus setaceus), fleabane (Erigeron bonariensis), and gorse (Ulex europaeus). Invasive vegetation management guidelines are outlined within the 2015 Maunakea Invasive Species Management Plan. OMKM employs a variety of weed management methods including: preventative invasive species inspections, early detection plant monitoring within the MKSR, practiced rapid response procedures, hand removal control activities, and regular monitoring of established populations. Data over the past four years shows an exponential increase in invasive fireweed within the MKSR and increased invasive plants at higher elevations. Hand removal control activities remove over 400 bags of invasive weeds each year just from around Halepōhaku and surveys have detected a few new non-native plant species. Although weed management strategies are diverse, OMKM faces the same issues as many programs across the island including a small staff, efficacy tradeoffs, herbicide restrictions, and an inability to control visitor introductions. 2017 goals include the development of a mid-elevation restoration plan, a fireweed control efficacy study, and continued development of invasive plant management efforts.

2017

Big Island Natural Areas Weed Management Forum

Keau‘ohana Native Rainforest Restoration

Jaya C. Dupuis

Malama O Puna, DLNR

Keau‘ohana Native Forest Reserve in the Puna District of Hawai‘i Island has the largest and most intact lowland wet forest remaining below 1,000 feet in elevation in the State of Hawai'i. This forest is a unique reservoir of rare native biodiversity, and is also the most optimal remaining critical habitat for the endangered ha‘iwale (Cyrtandra nanawalensis). Since 2014, the Keau’ohana Forest Reserve has undergone intensive restoration that eliminated most invasive species on > 30 acres of the most bio-diverse portion of the reserve, down-slope of Highway 130. The main target species have been waiawi (psidium cattleianum), and Clidemia hirta, however other important invasive species have included, Kukae maile (Paederia foetida), Melastoma septemnervium, thimble berry (Rubus rosifolius), and coleus (Plectranthus scutellarioides). Species in earlier stages of invasion include Cecropia obtusifolia, Trema orientalis, and Melochia umbellate. Despite damages caused by hurricane Iselle and subsequent ohi’a loss due to Rapid Ohi’a Death (ROD), Keau’ohana’s native forest is responding well to restoration measures. There is natural regeneration of numerous native species, including ohia seedlings. Species such as kopiko (Psychotria hawaiiensis), kolea (Myrsine lessertianna), lama (Diospyros sandwincensis), Hapu’u (Cibotium spp.), and mamaki (Pipturus albidus), provide sufficient shade in much of the forest. Native species such as ‘ohe (Poliscias hawaiensis), a rare yet fast growing native canopy tree, have been out-planted in open areas in need of shade. The broadcasting of mamaki seeds has proven to be an excellent restoration strategy. Having undergone intensive restoration, it is important now to follow-up with appropriate weeding efforts to eliminate the numerous invasive seedlings that are naturally regenerating due to the very abundant seed bank. Our primary goal to reconstitute the native forest composition (>90%) has been achieved. Our current goal is to maintain this, and expand upon its perimeters wherever possible. The project is currently half way through its second pass.

2017

Big Island Natural Areas Weed Management Forum

Using Foliar Spray Volume to Estimate Area & Number of Plants Treated

Joel Brunger

Big Island Invasive Species Committee

Reporting the area and number of plants treated is a typical requirement for invasive species control programs receiving grant funds. BIISC’s target species, Rubus sieboldii, is a dense ground-covering shrub, and it has proven difficult and time-consuming to accurately determine the area and count the number of plants treated during control operations. The BIISC Plant Crew has developed a method to use foliar spray volume to estimate these reporting data. A backpack sprayer was calibrated and timed while spraying 10 plots of 1 square meter of Rubus of varying canopy cover. The number of mature Rubus plants per square meter was counted in 10 plots with 100% canopy cover. The numbers of ounces and mature plants per square meter were determined, and these data were used to calculate the number of ounces per plant being sprayed. This foliar spray volume is then used in future operations to estimate both the area and number of plants treated. These estimates satisfy reporting requirements and can be used to track annual progress. Field staff can spend more time treating plants instead of collecting data, which increases a field crew’s productivity and efficiency. BIISC is employing this method on Rubus sieboldii but further applications could be useful for other species such as Pennisetum setaceum.

2017

Big Island Natural Areas Weed Management Forum

Using Google Earth Engine as part of a DST framework for invasive species management

Heather Kimball

Pacific Science Advocates

The Google corporation has recently renewed efforts to develop its Earth Engine platform. Earth Engine combines the functionality of mapping software, such as ArcMap, and remotely sensed imagery analysis software. Earth Engine has the advantages of: preloaded satellite imagery and imagery derived data products, a suite of scripts for image processing and analysis, the ability to import data sets from other platforms, and it is free to non-commercial users. Earth engine can also be called from, and send outputs to, other web applications. However, Earth Engine does not have an intuitive user interface and it requires some programing skills in JavaScript or Python to perform analyses. In this presentation, I will provide a brief demonstration on the functionality of Earth Engine and discuss options for integrating it into a geospatial Decision Support Tool (DST) platform. DSTs are platforms designed to facilitate communication, transparency and data driven decision making. DTS typically combine a knowledgebase containing the data relating to the decision, a logic model describing the relationships between decision criteria and a user interface that allows end users to further refine and evaluate criteria based on their priorities. Since Earth Engine is a JavaScript based platform, it shows promise as an integrated part of a light weight, flexible and low cost geospatial DST. I will conclude my presentation with a discussion on how an Earth Engine based DST might be designed for invasive species management applications.

2018

Big Island Natural Areas Weed Management Forum

Albizia Assassins

Bill Buckley

Big Island Invasive Species Committee

Albizia (Falcataria moluccana) is considered one of the most costly invasive species threats in Hawaiʻi. Growing at a rate of 10-15 feet per year, it produces abundant seeds that are wind dispersed, and develops limbs that are structurally weak and can easily break off in wind events. Albizia threatens critical infrastructure such as roads, power lines, and homes. During Tropical Storm Iselle in 2014, albizia trees were the main culprit in blocking roads and emergency routes in East Hawaiʻi, damaging or destroying dozens of homes and leaving residents without electricity for days or weeks. In 2013 Big Island Invasive Species Committee (BIISC), along with other stakeholders, created a task force specifically intended to mitigate the danger caused by albizia trees on important infrastructure. Three goals of the task force were to (1) delineate priority infrastructure; (2) Come up with a novel approach to treatment and management; (3) engage the community. Since this partnership began thousands of hazardous albizia have been mitigated along miles of priority infrastructure and almost 150,000 non-hazardous albizia trees have been treated on over 9,000 acres of land. For non-hazardous albizia treatment we use the incision point application using Milestone herbicide developed by University of Hawaiʻi Cooperative Extension Service. This method is cost-effective, safe, quick, easy and very effective. We’ve also worked to engage community members in 7 East Hawaiʻi Island communities to enable them to manage albizia on their property and within their community. Over 300 community members have attended a training since 2015, resulting in the volunteer treatment of thousands of albizia trees across the Big Island.

2018

Big Island Natural Areas Weed Management Forum

Automating Weed Detection from sUAS-derived Imagery with Machine Learning, Using Convolutional Neural Networks

Rebekah Loving, Morgan West, Morgan Friend, Ryan Perroy & Shawon Rahman

Department of Computer Science, University of Hawaii at Hilo, Hilo, HI; Department of Geography, University of Hawaii at Hilo, Hilo, HI

Resources for the control and eradication of weeds are limited, while current detection and removal efforts are expensive. To increase the effectiveness of available resources, we have designed and implemented a prototype automated weed detection software system for use with sUAS (small Unmanned Aerial System)-derived imagery. sUAS platforms can produce fine resolution imagery adequate to detect invasive plants, but current approaches require hours of manual classification and processing. We have developed two key technologies to help solve the difficulties faced by weed detection efforts. For the first component, we developed a convolutional neural network for detecting weeds of interest within imagery. Creating the convolutional neural network requires manually building a database of classified segments of images which contain the different weeds of interest. The second component is an algorithm which calculates the GPS coordinates of the identified plants. A land manager now only needs to load the imagery from a sUAS onto a computer and select the weeds of interest. The output is the location of the target weeds within each image. Our training set currently includes 376 images of Miconia calvescens from a variety of locations and altitudes. This training set can be expanded to include other species of interest. Our classification specificity and sensitivity for miconia are currently 88% and 83%, respectively. Hundreds of sUAS images can now be processed in under an hour, generating a display highlighting weeds of interest and a text file of plant coordinates.

2018

Big Island Natural Areas Weed Management Forum

Biological control of weeds: Updates for Big Island Natural Areas

Ken Puliafico, Tracy Johnson, Nancy Chaney, & Lori Bufil

Institute of Pacific Islands Forestry, USDA Forest Service, Research & Development, Pacific Southwest Research Station

Our Forest Service team at the Institute of Pacific Islands Forestry focuses on development of natural enemies for long term suppression of invasive plants in forests of the Hawaiian Islands and elsewhere across the Pacific. Here we summarize the current status of biological control projects targeting some of the most disruptive weeds in Pacific ecosystems: Psidium cattleianum (strawberry guava), Tibouchina herbacea, Miconia calvescens, Clidemia hirta and relatives. We are collaborating with forest managers on Hawaiʻi Island to distribute and monitor efficacy of Tectococcus ovatus, with the goal of slowing the spread of strawberry guava in native forests. We will provide updates on two agents currently proposed for biocontrol of weedy melastomes that are under review. We will also discuss our progress with other promising agents on target species such as albizia, faya tree and several others that we are working on in collaboration with local and international partners.

2018

Big Island Natural Areas Weed Management Forum

Developing Pest Management Applications With Unmanned Aerial Systems

Roberto Rodriguez, Ken Giles, Daniel Jenkins, & James Leary

Dept. of Molecular Biosciences and Bioengineering, University of Hawaiʻi, Mānoa, Department of Biological and Agricultural Engineering, University of California at Davis, & Dept. of Natural Resources and Environmental Management, University of Hawaiʻi, Mānoa

This is a collaborative project with a research and technology objective to develop, validate and certify unmanned aerial systems with HBT capabilities (UAS-HBT) in remote pest target elimination. We have developed a first-generation prototype HBT gimbal with controlled flight tests proving concept with a vertical takeoff and landing (VTOL) octocopter able to lift the 6 kg payload and an independent operator able to remotely engage and accurately discharge projectiles to target. Accuracy and precision of the treatment system is

2018

Big Island Natural Areas Weed Management Forum

Efficacy of Undiluted Herbicide Injections on Tropical Woody Species in Hawaiʻi

James Leary, Julia Lee & Jane Beachy

UH Mānoa, Cooperative Extension Services, Oʻahu Army Natural Resource Program

There are hundreds of exotic, woody species naturalized in Hawaiʻi, with many considered to be problematic, invasive weeds impacting natural areas and forested watersheds. Among conservation groups, the active ingredient triclopyr (TCP) is the most relied upon herbicide selection for woody species control, with a basal bark application of a 25% v/v oil adjuvant blend being the most typical method. Anecdotally, the technique is mostly successful, but without calibrations to report on effective dose, supporting the observation that effective applications are mostly compensated by high doses. Field efficacy trials were initiated in 2011 to determine if other registered active ingredients including: aminopyralid (AMP), imazapyr (IMZ) and glyphosate (GLY), along with aminocyclopyrachlor (ACP); would prove to be more effective in measured doses. Thereby expanding the “palette” of herbicide options and encouraging an optimized approach to pesticide use. These treatments were administered via injection with metered doses of undiluted formulations. Starting in 2011, replicated efficacy trials have been administered to naturalized stands of thirty species, all from different genera. Size was a variable among experimental units with basal diameters ranging 10-30 cm (50th percentile). Dose volumes were consistent within treatment designs and ranged from 2-4 ml per target (50th percentile) across experiments. Performance was measured by recording defoliation over time. The treatments ACP, AMP and IMZ were consistently strong performers (>80% defoliation) effective on 85%, 45% and 61% of treated species, respectively, while GLY and TCP were only effective across 21% and 27% of species, respectively. Median effective doses for ACP, AMP and IMZ were 2.0, 2.3 and 2.2 mg ae cm-2 (acid equivalent applied to area of basal cross section), respectively, while GLY and TCP were effective at 5.7 and 5.3 mg ae cm-2, respectively, with noticeable efficacy reduction at 90% defoliation observed in 90% defoliation typically observed 150-200 DAT. Effective control was determined for 73% of the species tested, with 50% of those species having a single herbicide option superior to the other herbicides and multiple options becoming less frequent among species. Furthermore, all effective options (i.e., ACP, AMP and IMZ) superseded TCP using this low-dose injection technique. The injection technique is proving to be an effective, efficient and more hygienic alternative to woody species control in Hawaiʻi, where performance outcomes are improved with inclusion of a more diverse herbicide inventory.

2018

Big Island Natural Areas Weed Management Forum

Hawaiʻi Wildfire Management Organization

Elizabeth Pickett, Pablo Akira Beimler, Melissa Kunz, Orlando Smith

HWMO Executive Director, Community Outreach Coordinator, PFX Coordination Assistant, GIS Specialist

In 2015, HWMO’s Technical Advisory Committee identified Hawaiʻi’s lack of consolidated, landscape-level information on vegetative fuels treatments used to reduce wildfire risk. In response, HWMO is developing island-by-island fire fuels management maps that will 1) provide information on existing vegetation management efforts, and 2) identify and prioritize additional future vegetation managemen projects for the purpose of fire mitigation. The goal of this presentation is to introduce the project and data collection process and provide an opportunity for Weed Management Workshop participants to provide information on their existing or desired fuels reduction projects and add to the statewide set of projects and priorities.

2018

Big Island Natural Areas Weed Management Forum

Kūmaipō Fire: Lessons Learned from a Partnership for Restoration

Clay Trauernicht, Amy Tsuneyoshi & Tamara Ticktin

UH Mānoa & Pacific Fire Exchange, Honolulu Board of Water Supply, UH Mānoa, Botany

We examined 14 years of Hawaiian forest regeneration after the 2003 Kūmaipō Fire and subsequent weed management and outplanting efforts in the Waiʻānae Mountains on Oʻahu. Abundant natural regeneration and outplants of the native tree Acacia koa formed a closed canopy across much of the burn site in 14 years. Other naturally regenerating native plants declined and nonnative species, primarily Clidemia hirta and Nephrolepis multiflora now dominate the understory. Outplanting significantly increased the native component of post-fire vegetation and contributed to some native regeneration at the final survey (in 2017). A key lesson is that restoration efforts must consider the longer-term forest dynamics. Natural declines in some nonnative species, (e.g., Buddleja asiatica) over time indicate opportunities to prioritize weed management. For re-establishing native species, although Acacia koa is excellent for short-term recovery, but other research shows that pure koa stands transition to mixed species canopies over time. Given that all of the naturally regenerating canopy trees at the final survey were nonnative (e.g., Schinus, Toona, Grevillea, Trema), it is likely that long-term persistence of native forest after fire will require not continued weed management, but active outplanting of a mix of native canopy trees.

2018

Big Island Natural Areas Weed Management Forum

Liko Nā Pilina Experiment: What species and treatments are having the greatest success, in terms of growth and invasion resistance

Rebecca Ostertag, Susan Cordell, Peter Vitousek, Amanda Uowolo, Nicole DiManno, Kaikea Blakemore, Shances Akima, Amy Durham, Mikkel Gantzler, Jonathon Kuntz, James Melcher, Kalena Spinola, & Israel Stillman

University of Hawaiʻi, Hilo, USDA Forest Service, Pacific Southwest Research Station, Stanford University

Restoration to a previous reference condition may not be feasible in all situations, due to lack of information, invasive species, or climate change. When site improvement is desirable, a valuable option is restoration based on functional traits, but this method requires experimentation. To meet the objectives of increased carbon storage, native biodiversity regeneration, and invasion resistance, we developed a restoration effort in a lowland wet forest in Hawaiʻi, employing both native and non-native (i.e., non-invasive) species with varying functional trait expression in experimental treatments. Core (n=4 per treatment) species were chosen based on expected C turnover rates (slow or moderate) while trait (n=6 per treatment) species were chosen based on functional trait redundancy or complementarity to the core species. Sixteen plots with similar vegetation structure, light levels, and soil nutrients were cleared of all invasive species and then planted into, while four additional ones were left uncleared as reference plots. The experimental restoration plots have been monitored for the last four years with a suite of parameters measured in order to evaluate the success of these hybrid communities. Topography has also been assessed across the site to examine how site conditions may influence outplant success and native recruitment. The restoration efforts at this site are being put to the test in the face of declining forest health with an 11% average annual rate of mortality being witnessed for the dominant canopy tree, Metrosideros polymorpha, due to disease caused by a Ceratocystis fungus. After four years of community development parameters measuring restoration success suggest that the MOD RED (i.e., moderate C turnover core – redundant traits) treatment is prevailing with high rates of survival, growth, canopy closure, and outplant litterfall, leading to greater invasion resistance, and thus lower plot maintenance efforts. In comparison, the SLOW COMP (i.e., slow C turnover core – complementary traits) treatment has shown greater reproduction in the early stages of this experiment, yet greater recruitment has not been recorded due to lower invasion resistance created by the outplants. Topography was found to be important with rougher plots resulting in greater sapling recruitment, and topographical depressions influencing outplant growth. In determining which of these treatments will be successful in the long-term we need not only consider the original goals of increased C storage, native biodiversity regeneration, and invasion resistance, but also which community assemblages will best mediate the impacts of a forest declining rapidly in terms of native canopy health.

2018

Big Island Natural Areas Weed Management Forum

Responding Hard and Fast on Soft Money

Springer Kaye, Joel Brunger,

Big Island Invasive Species Committee

Strong, stable funding for post-border management of invasive species is critical to ensure that new and sparsely established pest species do not create permanent, costly impacts to agriculture and conservation areas. Early Detection and Rapid Response capacity in Hawaiʻi is largely tax-payer funded, and affected similarly and simultaneously at the local, state, and federal level by strong shifts in the US economy, such as the 2007 economic recession. During the past five years, for example, the Hawaiʻi Invasive Species Council has received relatively strong and consistent funding, when compared to the previous five years (though at no point have funds been sufficient to meet statewide need). Ten years ago, the Big Island Invasive Species Committee adopted an Early Detection and Rapid Response (EDRR) approach to invasive species management, closing the chapter on Operation Miconia in favor of stopping "the next miconia." Six target species were selected to demonstrate the potential for eradicating species established, at varying degrees of severity, on the island of Hawaiʻi. In this presentation, we will examine progress made toward eradication of each species between 2008 and 2012, during the recession, and 2013-present. We discuss effective methods for systematic eradication of species, and other factors contributing to the economic recovery of ISC programs. An encouraging picture emerges, for those optimistic about Hawaiʻi's economic future and the adoption of the Hawaiʻi Interagency Biosecurity Plan.

2018

Big Island Natural Areas Weed Management Forum

Restoration of tropical dry forests at Puʻuwaʻawaʻa Successes & Challenges

Elliott Parsons, Edith Adkins and Kealakaʻi Knoche

Nāpuʻu Conservation Project

The Nāpuʻu Conservation Project manages state lands at Puʻuwaʻawaʻa where weeds threaten some of the last remaining fragments of native tropical lowland dry forest. It is well known that invasive weeds degrade dry forests through the promotion of wildfire, competition with native species for light, water, and nutrients, and prevention of native seedling establishment through space occupation. To mitigate these impacts, dry forest restoration efforts often focus on areas with existing native tree canopies as those areas are likely to have a native seed bank and are more cost effective to restore. Successful examples of this approach include the Kaʻūpulehu Dry Forest Preserve, and Kīpuka ʻŌwēʻowē at Puʻuwaʻawaʻa. What is less well known is whether fully degraded (i.e. 100% weed-infested areas with no natives left), can ever return to native-dominated dry forest, or if those areas are too far gone, or too expensive to recover. Understanding the range of conditions over which restoration can be successful is important as the vast majority of once native dry forest areas are now mostly, or fully dominated by weeds. Moreover, we have little information regarding the distribution of native and non-native trees across the landscape to help inform placement of conservation units where native trees dominate, or to help determine where non-native tree control efforts should be targeted. Here we report on weed removal and outplanting efforts across a range of conditions from areas with native canopy trees present and a non-native understory, to 100% weed infested areas. We will discuss the successes and challenges of working in those different conditions, as well as the results from over 7 years of restoration effort. In addition, we will report on the use of different technologies at Puʻuwaʻawaʻa used to help inform these efforts.

2018

Big Island Natural Areas Weed Management Forum

Yes, Albizia can be successfully controlled. Just ask the Samoans

Flint Hughes, Tavita Togia, James Leary

Institute of Pacific Islands Forestry, USDA-USFS, National Park of American Samoa, DOI-NPS, University of Hawaiʻi, Mānoa

It is often difficult, if not impossible to eradicate an invasive species from a given area, no matter the resources at one’s disposal. Here we describe an example of one such successful effort and the approaches used to achieve it. As of 2001, approximately 40% of the island of Tutuila, American Samoa was infested with large stands of the fast growing, N-fixing tree, Falcataria moluccana – known as Albizia in Hawaiʻi and Tamaligi in American Samoa. Research found that when Tamaligi trees are eliminated, native Samoan forest species quickly reestablish and persist. In 2017, field crews from the National Park of American Samoa (NPAS) terminated the last remaining accessible Tamaligi population of 1,500 trees on Tutuila Island. Since the beginning of September of 2014, field crews killed a total of 12,350 mature Tamaligi trees across 19 villages and in the process restored approximately 4,120 acres of native forest. This greatly exceeded the number of Tamaligi killed by NPAS staff and their partners over the previous 13 years (i.e., 7,237 mature trees) since 2001. This dramatic increase in numbers killed came from switching from a manual approach whereby trees were laboriously girdled with machetes to a more efficient method using the highly effective herbicide, Milestone (a.i. aminopyralid). Clearing Tamaligi from these forests has protected important habitats of Samoa’s native flora and fauna and reduced the negative impacts of Tamaligi on watershed-streams and coastal habitats. Strong support of American Samoa’s village community enabled NPAS staff to accomplish the daunting and often dangerous control efforts. American Samoa’s Office of the Governor also supported and helped coordinate efforts with the traditional leadership of the affected villages. The importance of having many conversations with village communities in a respectful, candid and cordial manner cannot be overstated as a means to success. Further, these efforts have employed numerous village youth whose work has produced tangible results. Views of dead Tamaligi populations across landscapes have provided a powerful message to the Island’s communities about the importance of saving Samoa’s rainforests and that it can be accomplished by American Samoa’s people. Job opportunities to improve forest health have provided a source of income to many families, in turn, creating investments back to their villages, and justifying public support for government conservation initiatives.

2015

Maui Nui Natural Areas Weed Management Forum

Bocconia frutescens: Biology, Ecology & History of Invasion in the Hawaiian Islands

Chuck Chimera

PCSU

Bocconia frutescens (Papaveraceae), commonly known as the plume poppy, is a short-statured Neotropical tree native to much of Central and South America and the West Indies. It is naturalized in dry and mesic forests on the islands of Maui and Hawaiʻi, where it is capable of forming dense stands that can exclude the establishment of native species. It can reach reproductive maturity within four to six years, and produces tremendous numbers of seeds with fleshy arils that facilitate its dispersal by frugivorous birds. It also forms a long-lived seed bank, is able to resprout after repeated cutting and requires herbicide applications for effective control. It tolerates a broad range of environmental conditions along a large elevation gradient within its native range, suggesting that it could further encroach upon additional native and non-native habitats within the Hawaiian Islands, and has the potential to become invasive in similar tropical ecosystems worldwide. The US Fish & Wildlife Service lists Bocconia as a primary threat to a number of endangered species endemic to Maui and Hawaiʻi. Because of the current and potential impacts, Bocconia was designated a state noxious weed, and is the target of containment and control efforts on Hawaiʻi island and on leeward East Maui respectively. It is also recognized as a threat to similar habitats in other areas or islands outside its current invaded range, and is an early detection target of the Kauaʻi, Oʻahu and Big Island Invasive Species Committees.

2015

Maui Nui Natural Areas Weed Management Forum

Ginger Control in the East Maui Watershed

Givonn Osterneck

East Maui Mountains Watershed Partnership

With the successful management of ungulates in the core east Maui watershed, the partnership has adjusted its focus to weed management. Himalayan ginger poses a devastating and irreversible habitat modifying threat to this high-elevation rainforest ecosystem. From 2008 when ginger was initially detected in the area, through the 2013- 2015 process of completing an initial first pass of control through the infestation, EMWP has learned a lot in the process. EMWP was challenged by a dense canopy making aerial detection nearly impossible, low confident detection in dense uluhe areas, rhizomes traveling underground with no vertical stocks, along with other challenges. EMWP will work in the future to define an appropriate retreatment interval, detect new populations spread by birds before they grow too large to manage, control difficult to reach epiphytic individuals and plan the next priority areas for control.

2015

Maui Nui Natural Areas Weed Management Forum

Planning for Kiwikiu reintroduction: Habitat restoration in Nakula Natural Area Reserve

Chris Warren

Maui Nui Forest Bird Recovery Project

Maui Nui Forest Bird Recovery Project has been conducting experimental restoration trials in the Wailaulau unit of Nakula NAR since 2012 to inform managers of the most efficient and effective methods for restoring the forest in the reserve. Concurrently we have been conducting large-scale outplantings throughout this same area to increase available habitat for Kiwikiu following the planned reintroduction of the species. Non-native grasses dominate large areas throughout Nakula. However, natural regeneration of some native species within grassland areas creates a mosaic of desirable and undesirable species making removal of grasses to support native recruitment challenging on the landscape-scale. Our outplanting areas are designed to provide corridors of habitat connecting existing forest patches. Prior to planting herbicide was applied only to where each seedling was to be planted. The restoration trials have shown removal of non-native grasses to significantly enhance natural regeneration of some species and we are also preparing strips where herbicide will be applied and grasses removed to enhance recruitment without outplanting. As of March, 2015 MFBRP has planted > 8 ha in outplantings corridors and we are planning an additional 5.6 ha to be planted by January 2016. An additional 2.5 ha of erosion scars have been planted throughout the unit. The remote and rugged nature of the site restricts many restoration activities to manual methods only. Unlike other parts of Nakula, natural regeneration and existing native vegetation in much of the Wailaulau unit prohibit broad-scale, aerial application of herbicide and application must be done on the ground. Our goal is to continuing our outplanting efforts in corridors and erosion scars in remaining areas. We also plan to plant additional understory species to areas with existing canopy cover to increase habitat quality and important Kiwikiu food sources.

2015

Maui Nui Natural Areas Weed Management Forum

Efficacy of Undiluted Herbicide Injections on Tropical Woody Species in Hawaiʻi

James Leary

CTAHR

There are hundreds of exotic, woody species naturalized in Hawaiʻi, with many considered to be problematic, invasive weeds impacting natural areas and forested watersheds. Among conservation groups, the active ingredient triclopyr (TCP) is the most relied upon herbicide selection for woody species control, with a basal bark application of a 25% v/v oil adjuvant blend being the most typical method. Anecdotally, the technique is mostly successful, but without calibrations to report on effective dose, supporting the observation that effective applications are mostly compensated by high doses. Field efficacy trials were initiated in 2011 to determine if other registered active ingredients including: aminopyralid (AMP), imazapyr (IMZ) and glyphosate (GLY), along with (unregistered) aminocyclopyrachlor (ACP); would prove to be more effective. Thus, expanding the “palette” of herbicide options. These treatments were administered via injection with metered doses of undiluted formulations. Starting in 2011, replicated efficacy trials have been administered to naturalized stands of thirty species, all from different genera. Size was a variable among experimental units with basal diameters ranging approximately 10-30 cm (50th percentile). Dose volumes were consistent within treatment designs and ranged from 2-4 ml per target (50th percentile) across experiments. Performance was measured by recording defoliation over time. The treatments ACP, AMP and IMZ were consistently strong performers effective (>80% defoliation) on 85%, 45% and 61% of treated species, respectively, while GLY and TCP were only effective across 21% and 27% of species, respectively. Median effective doses for ACP, AMP and IMZ were 2.0, 2.3 and 2.2 mg ae cm-2 (acid equivalent applied to area of basal cross section), respectively, while GLY and TCP were effective at 5.7 and 5.3 mg ae cm-2, respectively, with noticeable efficacy reduction at 90% defoliation observed in 90% defoliation typically observed 150-200 DAT. Effective control was determined for 73% of the species tested, with 50% of those species having a single herbicide option superior to the other herbicides and multiple options becoming less frequent among species. Furthermore, all effective options (i.e., ACP, AMP and IMZ) superseded TCP using this low-dose injection technique. The injection technique is proving to be an effective, efficient and more hygienic alternative to woody species control in Hawaiʻi, where performance outcomes are improved with inclusion of a more diverse herbicide inventory.

2015

Maui Nui Natural Areas Weed Management Forum

TNC Weed History and Management

Kerri Fay

The Nature Conservancy, Maui

The goal of TNC’s weed control program is to maintain large native-dominated core areas within Waikamoi Preserve and adjacent areas that are free of the highest priority habitat-modifying weeds, and prevent the introduction and spread of problem weeds to areas where they are not currently established. The most important aspects of our weed control program are to minimize current disturbances to intact native communities, reduce infestation size of priority weeds with a focus on outliers, while first surveying for and controlling outliers, and to prevent the introduction of additional invasive plant species. The highest priority is the containment and localized eradication of Himalayan ginger, primarily due to its established range, rate of spread, and aspects of habitat modification. In FY2015 we swept 105 acres and treated 1,726 m^2 for Himalayan ginger. We are challenged with a no herbicide use limitation when close to county water infrastructure. We started manual control but moved to surveying and mapping. In a 2.5 acre area we had 316 ginger patches along our new fenceline. Within the last few years we have seen a dramatic increase in Pinus species popping up across the higher elevations of the preserve. We treated 3,459 Pinus on the ground in a 23 acre area in FY15. In FY14 we treated about 400 pines in about a 1000 acre area via low volume aerial spray. Other small populations of Setaria palmifolia and Delairea oderata were treated as encountered. Low volume injection trials on 100 foot conifers proved successful resulting in less herbicide use. FY16 weed management will focus on control of 74 acres of ginger and 20 acres of Pinus.

2015

Maui Nui Natural Areas Weed Management Forum

Have We Narrowed Down Priorities to Achieve Realistic Goals to Mitigate Habitat Loss?

Pat Biley

The Nature Conservancy, Maui

Assuming most managers are in agreement on target species and strategic management approaches, we should investigate ways to collaborate to get the biggest bang for buck, especially near shared management borders. Do we have efficient 'satellite to core' approaches, most current GIS for range and mapping methodology, and best management practices in terms of chemical control? What targets are assumed to have eventual biological control and will that be enough to contain further spread to non-infested sites? Where will we draw the 'line of death' in terms of controlling outlier populations when we cannot practically take on core populations? Is there a reliable budget to continue work into a 5 year management plan?

2015

Maui Nui Natural Areas Weed Management Forum

The Perils of Pampas in Precarious Places

Mike Ade

Maui Invasive Species Committee

Cortaderia jubata has invaded a diverse range of habitats and forest types on the island of Maui, including dry (500 mm annual rainfall) to very wet (up to 5,000 mm annual rainfall) areas, dryland, mesic, and wet koa-ʻōhiʻa forests, and subalpine shrublands. It threatens to exclude native understory flora and impair watershed integrity. Coordinated efforts of the Maui Invasive Species Committee (MISC) to control pampas grass began in 1998, and has included extensive aerial helicopter and ground control. The combination of aerial and ground efforts in the most densely infested area on East Maui has proven successful, reducing the average number of mature plants found per acre from >5 in 2008 to less than 1 by 2014. Other locations on Maui face different challenges to successful control, including sociological (landowner reluctance to permit control in residential areas), topographical (extreme terrain), and climatological (inclement weather). In the mountains of West Maui, inhospitable terrain has limited the ability to stage ground crews in the area to find and control plants before they reproduce. More effective aerial treatment methods need to be evaluated. GIS is used as a tool to highlight strategies, progress, and challenges associated with controlling pampas grass populations throughout Maui.

2015

Maui Nui Natural Areas Weed Management Forum

Invasive Pine Detection and Mapping Using High Spatial Resolution Satellite Remote Sensing

Jonathan Marshall

Haleakalā National Park

The objective of this project is to use high spatial resolution satellite data and remote sensing analysis software to create detection maps of invasive pine trees across montane East Maui. Invasive pines pose a significant threat to the diverse native ecosystems of East Maui. To effectively manage these pines, it is important to have a complete spatial understanding of their extent. Accurate pine maps will be useful to East Maui land managers and will allow for more efficient use of limited control resources. Satellite remote sensing is a capable tool due to its ability to detect land cover characteristics across large spatial areas and with fine spatial detail. Detecting pines will rely on established remote sensing vegetation classification methodologies which take advantage of the unique spectral signatures of plants. This project has conducted preliminary research that shows that the spectral signature of pines is separable from the surrounding vegetation. Using this unique spectral characteristic, this project will map pines across montane East Maui and estimate population density and the size class of individuals. These results will be integrated with GIS, and provided to land managers as a management resource. The procedural work for the remainder of 2015, involves the core application of the pine spectral signature to vegetation classification algorithms that will classify and map East Maui. Current challenges include spectrally separating different pine species from each other and examining the viability of more spatially accurate satellite data. Resources for this project include remote sensing and GIS software available through the University of Hawaiʻi at Mānoa’s Geospatial Analysis and Remote Sensing Lab. Management data and GPS training data for pine trees has been provided by the Haleakalā National Park Vegetation Management team. The primary project deliverables are expected early Summer of 2016.

2015

Maui Nui Natural Areas Weed Management Forum

13 years of Bocconia Control at Kanaio Natural Area Reserve: Evaluation and Lessons Learned

Byron Stevens

DLNR, DOFAW, NAR

Tree Poppy (Bocconia frutescens, Papaveraceae) has been present on the Southern slope of Haleakalā volcano since at least 1920, and is now widespread throughout dry and mesic habitats. Attempts to control this plant within the Kanaio Natural Area Reserve began in 2003, and are on-going within a 1480-acre area. Control involves crews on foot making sweeps across rugged lava terrain and basal bark herbicide treatment when Bocconia is located. Several years are required to make a complete sweep of the Reserve. Monitoring plots were established at the beginning of the effort and periodically revisited to assess trends in the infestation. The initial control effort appears to have been successful in reducing the number of mature plants, but recruitment of young plants has increased, perhaps due to recent increased rainfall and the removal of grazing animals from the area. A side benefit of the intensive sweeps has been location and control of incipient populations of other weeds, as well as the discovery of rare plants and archaeological sites.

2015

Maui Nui Natural Areas Weed Management Forum

Bocconia frutescens: extent and strategies for control

Keahi Bustamente

Leeward Haleakalā Watershed Restoration Partnership

Bocconia frutescens, or Tree Poppy, is a large erect shrub that has impacted native forest on the Leeward slope of Haleakalā, Maui, Hawaiʻi for many decades now. It was first collected in 1920 on an old road in Kanaio and by 1974 single plants were showing up in Auwahi and Kula. Although its range on Maui is currently limited to Leeward Haleakalā, it will undoubtedly threaten nearby windward preserves as it slowly increases its range via bird dispersal, prolific seeding, and an ability to germinate in a variety of conditions. Since the early 2000’s, when LHWRP began management of the species, over 30,000 plants have been controlled. Aerial surveys of the known range were completed in 2015. The Partnership is working towards creating estimates for long-term feasibility of initial control and maintenance in our project areas. Current goals are to control all mature and immature Bocconia plants that are incipient, as well as those in close proximity to rare species. A long-term goal has been to create an adult Bocconia-free fenced conservation area at Kahikinui (across DHHL and DLNR ) with a buffer to limit potential for bird dispersal has been set. However, control in this area has proven challenging as many plants occur on steep to vertical terrain, accessible only by HBT or rappel.

2016

Maui Nui Natural Areas Weed Management Forum

Gorse Management at Puʻu Pahu

Chris Radford

East Maui Mountains Watershed Partnership

Gorse (Ulex europaeus) is one of the most noxious and invasive weed species in Hawaiʻi. This thorny, perennial shrub forms tall dense stands which shade out surrounding vegetation and displace native plants by out competing them. Gorse populations can develop into impenetrable monotypic thickets that render invaded areas completely unproductive, impassible, and extremely prone to fire due to its abundant dead material and oily, highly flammable foliage and seeds. On Maui, Gorse infestations are typically found in higher elevation pastures and natural areas, particularly on the slopes of Haleakalā. The East Maui Watershed Partnership and Haleakalā Ranch Company are working together to control Gorse in and around the Puʻu Pahu Reserve. The reserve encompasses roughly 1,200 acres of subalpine shrubland that is home to a number of rare and endangered native plant and animal species. It is located on Haleakala Ranch property between 6,000 and 8,000 ft and is directly adjacent to Haleakalā National Park’s Crater District. Gorse control by EMWP is typically carried out in two phases. First, sweep to detect all weed populations while controlling the small populations, then target and control the higher population densities detected during the sweeps. Given the vastness of the reserve relative to our resources, we delimit what we consider reasonably sized areas to be thoroughly swept and controlled each year. The target areas range from approximately 50 to 100 acres. The area being covered each year is intended to follow a systematic approach that allows for a regular revisit interval. EMWP’s primary objectives for this project are to control Gorse inside and in the immediate vicinity of Puʻu Pahu Reserve, as well as document and control incidental priority weeds. We are supplementing these efforts with a volunteer based native plant outplanting program within the reserve.

2016

Maui Nui Natural Areas Weed Management Forum

Biology and Management of Incipient Miconia in the East Maui Watershed

James Leary

UH Mānoa, Natural Resources and Environmental Management

Miconia was introduced to East Maui as a single horticultural specimen circa 1970. The management of miconia commenced two decades later and continues on today. Native to Central and South America, this species has many biological attributes that make it a highly successful invader of Hawaiʻi including high adult fecundity and frugivorous dispersal of progeny. In less than 40 years, incipient miconia populations have invaded remote sections of the East Maui Watershed. In 2012, Herbicide Ballistic Technology (HBT) was introduced as a novel treatment platform greatly enhancing helicopter interventions against these incipient populations. In five years of operations, we have conducted over 100 missions, approaching 500 hours of operational flight time (OFT), treating over 20,000 high-value, targets. With reliance on published science out of Tahiti and Australia and basic GIS analysis of our own empirical data, we have developed a dispersal kernel showing that 90, 95 and 99% of all incipient targets establish within 210, 302 and 602 m of the nearest mature plant, respectively, with rare (i.e., 1%) long-distance dispersal events occurring at up to 1644 m. Thus, showing a single, autogamous (self-fertile) plant directly impacting 850 ha of the watershed. Based on this new knowledge, the total area impacted by mature miconia in 2012 was 20,482 ha. In 2016, the total impact area expanded 2.2%, reaching 20,934 ha. We estimate this area impact to persist for over four decades accruing management costs approaching $150K (with inflation) in order to achieve total extirpation of progeny within the impact zone. Our goal is to use these new model parameters for optimizing containment strategies with effective impact reduction and highest return on future cost avoidance.

2016

Maui Nui Natural Areas Weed Management Forum

Calibrating a helicopter long-line sprayer treating incipient gorse patches in Humuʻula, Big Island

James Leary

Dept. Natural Resources and Environmental Management, University of Hawaiʻi, Mānoa

N/A

2016

Maui Nui Natural Areas Weed Management Forum

Invasive Plant Species Management on Lānaʻi

Mike Donoho

Pūlama Lānaʻi

After a century of large-scale agriculture and presence by big game animals, Lāna‘i is dominated by non-native plant species, including several invasive species. On an island that is 98% privately owned, it is the responsibility of the landowner, Pūlama Lāna‘i, to not only manage established weed populations, but also prevent the introduction of new invasive species to the island to the extent possible. Lāna‘i is fortunate to be free of fountain grass (Pennisetum setaceum), ivy gourd (Coccinia grandis), or ragweed parthenium (Parthenium hysterophorus) and Pūlama is working to keep it as such through the efforts of its Natural Resources Department. Pūlama is developing its Natural Resource Management Plan, which will outline its strategies to manage, control and in some cases, eliminate established invasive species on the island.

2016

Maui Nui Natural Areas Weed Management Forum

Pine Management in the Upper East Maui Watershed

Kerri Fay

The Nature Conservancy Maui

2016

Maui Nui Natural Areas Weed Management Forum

Miconia Ground Strategies in East Maui

Bryan Berkowitz

Maui Invasive Species Committee

Miconia calvescens has invaded approximately 21,000 acres on East Maui with a potential range of 119,000 acres of suitable habitat. On Maui, it grows in lowland to montane tropical rainforest at altitudes between 10 meters and 850 meters with 3,000mm - 7,000mm of rain per year, and threatens to exclude native understory flora and impair watershed integrity. Coordinated efforts of the Melastome Action Committee (MAC) to control Miconia began in 1991. This led to the formation of the Maui Invasive Species Committee (MISC) in 1999 and has included extensive aerial helicopter and ground survey and control. Recognizing the magnitude of the core infestation in Hāna, control methods are largely centered on containment and protection of high value native forest and vectors such as roads. This work seeks to describe the parameters of the Miconia project that guide and direct control methods. GIS is used as a tool to highlight strategies, progress, and challenges associated with controlling Miconia populations throughout East Maui.

2016

Maui Nui Natural Areas Weed Management Forum

Designing an Herbicide Ballistic Technology Platform for Unmanned Aerial Systems (HBT-UAS)

Roberto Rodriguez

Dept. Molecular Biosciences and Bioengineering, University of Hawaiʻi, Mānoa

Herbicide Ballistic Technology (HBT) consists of encapsulated herbicide formulations in soft-gel projectiles delivered by an electro-pneumatic marker. The HBT platform has proven to be a valuable tool to treat isolated plant targets during surveillance operations, by removing the need for an additional flight operation to treat the target. Unmanned Aerial Systems provide an on-demand platform for remote sensing and have been used for mapping in conservation. We are developing a UAS compatible HBT platform (HBT-UAS) to rapidly treat single targets from a UAS. The proposed HBT-UAS falls under the regulations contained within 14CFR§137 Agricultural Aircraft Operations and the Hawaiʻi Pesticide Law and operations must be reviewed by relevant authorities for compliance. Adaptation of the HBT platform to provide UAS with treatment capabilities will reduce the demand for manned aerial operations in some areas allowing for these resources to be applied in areas that are not compatible with UAS limitations. In order to realize the utility of HBT-UAS, we are moving forward with developing trained aerial management teams consisting of pilots, payload operators and visual observers. The course will consist of both ground and flight training. Ground training will include topic areas required by the FAA in 14 CFR §107.73, based on the contents of 14 CFR, Aeronautical Information Manual, and Pilot's Handbook of Aeronautical Knowledge, and areas related to successful operation of UAS (e.g., filing NOTAMs, interpreting aviation weather resources, completing logbooks and reports, etc.). Flight training will incorporate maneuvers from the FAA Airplane, Glider, and Helicopter Flying Handbooks that apply to UAS including takeoffs and landings, performance maneuvers, and emergency procedures.

2016

Maui Nui Natural Areas Weed Management Forum

Web and mobile platforms for conservation and land management

Sam Aruch

Natural Resource Data Solutions, LLC

Natural Resource Data Solutions is building a new web application to collect and mange field data, track project progress, and produce reports. This tool is the culmination of over 15 years of experience performing fieldwork and building databases for conservation mangers throughout Hawaiʻi. We will provide a hands on demo of the application, its functionality, and integration with GIS, mobile data collection and other tools.

2016

Maui Nui Natural Areas Weed Management Forum

Aerial Pine Control – Past, Present and Future

Jonathan Marshall

Haleakalā National Park

Haleakalā National Park (HALE) is home to high elevation native shrubland and subalpine ecosystems that are crucial habitat for many endangered Hawaiian plants and animals. These habitats are threatened by non-native plant species such as pine trees. A 2007 fire in Polipoli State Park (is thought to have) dispersed seeds across montane East Maui. In addition, nearby forestry populations continually disperse seeds across much of the park. Pine species of concern include Monterey Pine (Pinus radiata), Mexican Weeping Pine (Pinus patula), and Maritime Pine (Pinus pinaster). Immediate control of newly established pine populations is necessary to prevent competitive exclusion of essential native habitat. HALE vegetation management and Pacific Islands Exotic Plant Management Team (EPMT) personnel have been controlling pines for decades, but recent efforts have included intensive aerial precision treatment and ground crew herbicide applications. These techniques are efficient and effective methods for controlling remote, inaccessible, and large trees. Additionally, newly implemented satellite remote sensing tools allow us to plan control operations through the precise pinpointing of target trees and can allow for post treatment monitoring of efficacy through mortality detection. Remote sensing and continued proactive ground and precision helicopter application, driven by growing understanding of the scope and complexity of the problem, will drive future management.

2017

Maui Nui Natural Areas Weed Management Forum

Invasive Weed Management in Highly Impacted Landscapes

Keahi Bustamente

Leeward Haleakalā Watershed Restoration Partnership

Since 2013 LHWRP has increased its focus and efforts to manage invasive Pine species on Leeward Haleakalā. With a small field crew and limited resources, for such a large area, partnerships with surrounding land owners and land managers has become an integral part of the control effort. In 2016, over 600 acres was cleared of 1200+ plants at Haleakalā Ranch's Puʻu Pahu Preserve on the West slope of Haleakalā. This was achieved with help from over 50 people, from multiple agencies, in less than two days. Overall, the LHWRP strategy has been simple, remove outliers and re-sweep areas every two years when possible. In 2018 another multi-agency ground sweep will be conducted on the South slope to control remaining outliers which threaten biologically sensitive areas like Auwahi and the Kanaio NAR, as well as the Nakula NAR.

2017

Maui Nui Natural Areas Weed Management Forum

Early Movements of Tectococcus ovatus in West Maui

Chris Brosius

West Maui Mountain Watershed Partnership

Non-native, habitat modifying Psidium cattleyanum (strawberry guava) is currently among the greatest threats to the health of the West Maui Mountains watershed. An integrated approach will be needed to control the spread given its aggressive use of habitats over challenging terrain. P. cattleyanum was brought to Hawaiʻi in 1825 from Brazil as an ornamental plant. It is extremely fast growing, resilient, animal and bird dispersed, monotypic, and water thirsty. In West Maui, approximately 5,000 acres are already monotypic (~10% of the entire WMMWP area). These dense thickets are primarily in historically disturbed areas proximate to the Forest Reserve boundary and on valley floors. Small satellite populations have become established up to 4,000’ and individuals have been found up to 4,900’ elevation. Habitat modeling suggests this species has the ability to invade the entirety of the West Maui watershed if left unchecked. This presentation will briefly review our control approaches to date before focusing on early lessons learned regarding the establishment of the biological control, Tectococcus ovatus. We will explore potential T. ovatus translocation methods to help accelerate the spread of the species and propose integrated strategies which may further future P. cattleyanum control efforts.

2017

Maui Nui Natural Areas Weed Management Forum

Valuating Conservation Activities in Waikamoi Preserve

Chris Wada

University of Hawaiʻi Economic Research Organization

The objective of this research is to estimate the value of ecosystem services protected by watershed conservation activities at The Nature Conservancy’s Waikamoi Preserve on the island of Maui. Projections of monetized benefits, together with trajectories of conservation costs, are used to calculate net present value, payback period, and return on investment. We find that conservation activities at Waikamoi Preserve protect an estimated 9,657 million gallons of freshwater yield over the next fifty years. The estimated present value of groundwater recharge benefits, calculated in terms of avoided future costs, is $7.5 million. When taking into account ecosystem services in addition to freshwater provision, the net present value is $8.5 million, and the return on investment is 26% for the planning period ending in 2067. Because much of the watershed protection costs are front-loaded while benefits are back-loaded, the payback period for investment is 41 years.

2017

Maui Nui Natural Areas Weed Management Forum

Ginger Control Efforts by EMWP

Chris Radford

East Maui Watershed Partnership

The East Maui Watershed Partnership (EMWP) has been conducting focused efforts to control Himalayan Ginger (Hedychium gardnerianum) since 2014, targeting populations on the windward side of East Maui. We have completed at least one sweep across approximately 167 acres since control work began. This presentation will provide some background on EMWP’s control efforts for ginger, as well as a broader outline of our management strategy for this target. Discussion will focus on our current treatment methods, recommended retreatment interval period, as well as possible resolutions to current limitations and challenges.

2017

Maui Nui Natural Areas Weed Management Forum

Accelerating the Restoration Trajectory of Acacia koa

James Leary

Dept. Natural Resources and Environmental Management, University of Hawaiʻi, Mānoa

2017

Maui Nui Natural Areas Weed Management Forum

Kahikinui and Nakula NAR Habitat Post Ungulate Exclusion

Jennifer Learned

Maui Nui Seabird Recovery Project

Ungulate exclusion within the upper Kahikinui Forest and Nakula Natural Area Reserve began in 2014 with the completion of ungulate-proof fencing and the removal of goats from the area. Grazing by feral ungulates has altered the vegetation community and the relative abundances of native and non-native plants throughout the area, including high-elevation alpine and sub-alpine shrub habitats. We’re working to characterize the habitat and document responses to the release from grazing pressure as part of long-term monitoring of the resident Hawaiian petrel (Pterodroma sandwichensis) colony. In March 2017, we measured physical characteristics and conducted the first annual vegetation survey. We divided the upper reserve (above 6800 ft.) into 8 gradsects, each spanning 300 feet in elevation. 10m x 10m permanent plots were randomly generated within each gradsect to represent 0.01% of the total area (n=55). We estimated percent cover for all species within each plot (standard Relevé method), measured slope, aspect, altitude, and characterized surficial geology. Endemic species are more common than naturalized species (7 out of the top 10 encountered species) and contribute to greater vegetative cover (average 5.4% cover vs. 0.6%). Grasses are the most common naturalized species, and have significantly higher coverage than native grasses only at lowest elevations. Opposed to elevation alone, distance from the ridgeline determines a grass-dominated vs. shrub-dominated habitat. These data are the first attempt to characterize the vegetation community within the fenced reserves. Future annual assessments within the permanent plots will document habitat response to ungulate exclusion. In addition, we will add plots to high-density petrel burrowing locations. We will assess habitat variables in conjunction with burrow site selection to better understand landscape requirements for the colony. Continued monitoring of the habitat on leeward Haleakala will inform reserve management strategies and Hawaiian petrel protection.

2017

Maui Nui Natural Areas Weed Management Forum

Update on Weed Control Efforts in Waikamoi

Keoki Kanakaokai

The Nature Conservancy, Maui

The goal of The Nature Conservancy’s weed control program in Waikamoi is to maintain large native-dominated core areas within the 8,951 acre preserve and adjacent areas that are free of the highest priority habitat-modifying weeds, and prevent the introduction and spread of problem weeds to areas where they are not currently established. The most important aspects of our weed control program are to minimize current disturbances to intact native communities, reduce infestation size of priority weeds with a focus on outliers, while first surveying for and controlling outliers, and to prevent the introduction of additional invasive plant species. The highest priority is the containment and localized eradication of Himalayan ginger (Hedychium gardnerianum). The control of gorse (Ulex europaeus), pines (Pinus patula and Pinus radiata), and Blackwood acacia (Acacia melanoxylon) follow closely with the goal of suppression, while the detection and prevention of establishment by species like strawberry guava (Psidium cattleyanum) and clidemia (Clidemia hirta) requires constant vigilance. Adapting strategy and incorporating innovation will be key to overcoming challenges in dealing with these highly successful invaders.

2017

Maui Nui Natural Areas Weed Management Forum

The Double Edge of Success: MISC Eradicable Species

Mike Ade

Maui Invasive Species Committee

In presenting an overview of Maui Invasive Species Committee’s eradicable species targets that includes a definition of an eradicable, the selection process, a slide presentation of targets, brief history of control and current coverage, Mike Ade and Christian Visoria will be discussing the success of this work and merits of continuing this program indefinitely as well as the downside of successful control work that includes lessened likelihood of staff, partners, volunteers and the public to find and identify these targets in a field setting. The overall focus of the presentation will be on the factors that contribute to problems with identifying and controlling plants in a field setting that have arisen as a result of successful control work. This will include discussion on relying on visual aids to enable crew, partners and the public to find or identify plants as opposed to identifying plants in the field and ways in which identification issues can be somewhat mitigated through successful partnerships and increased education that incorporates a strong PR component into the survey and control strategy. Also discussed is the difficulty of attaining and claiming eradication of many of our eradicable targets, not only due to the difficulties expressed in relation to the reduced visibility of these targets as successful control progresses, but also due to a variety of additional factors that include reintroduction through the landscape/nursery trade as well as imports of non-targeted plants and even potting soil amendments and difficulties with access to private land/property.

2017

Maui Nui Natural Areas Weed Management Forum

Landcover Maps for Natural Resource Management in Hawaiʻi

Matt Lucas

Dept. of Natural Resources and Environmental Management, University of Hawaiʻi, Mānoa

Remote sensing is a powerful tool for rapidly mapping landscape scale vegetation extents and change. However, too often a disconnection exists between where, when and why remote sensing products are produced and their application to management. This means that place based managers often apply un-intended and/or outdated map products to convey or measure valued resources across their management area. This talk will focus on learning about what vegetation and land-cover products exist for Hawaiʻi as well as an overview of the attributes, and intended use of these products. Additionally, this talk will briefly introduce Google’s cloud-based global remote sensing platform ‘Google Earth Engine’ (GEE). GEE combines a huge catalog of geospatial datasets with high-level analysis capabilities that run on remote supercomputers accessed through a web-based platform. This is making remote sensing data easily available and sharable for scientists and managers alike, thus increasing ability to track changes across any landscape. Finally, this talk will conclude with the introduction of a newly developed dynamic landcover product which identifies potential areas and rates of land cover change statewide. This new product will be used to showcase historical vegetation change and its utility for evaluating past, current, and future restoration and weed control efforts, as demonstrated at several Hawaiian management sites. Talk will conclude with a group discussion with particular focus on participant input of the utility, interface and potential applications, of this product in the context of management action evaluation, planning and reporting.

2015