Invasive Plants — Maui Invasive Species Committee (MISC)

Fountain grass threatens dryland ecosystems

Posted on April 1, 2020 by Lissa Strohecker

Jared Clapper with Hāna Lima Land Management, working on behalf of Haleakalā Ranch, was part of a team responding to an infestation of invasive fountain grass in proximity to Pu‘uokali above Kīhei. Fountain grass has a reputation for fueling a cycle of brush fires and is one of the greatest threats to the remaining dryland forest ecosystems.

On the leeward slope of Haleakalā above Kīhei rises a red dirt cinder cone named Puʻuokali. Puʻuokali means “the hill of waiting,” and is said to be one of several mo‘o (lizard deities) who were transformed into cinder cones on the summit. From her prominent vantage, Puʻuokali watches over her daughter, Puʻuoinaina on the island of Kahoʻolawe. As visible as Puʻuokali is to Maui residents, she also has her secrets. Inside the cinder cone is an intact dryland forest – a representation of the most diverse and most threatened ecosystem in Hawaiʻi. This native oasis was forgotten about until the early 1980’s when a brush fire broke out nearby and biologists rediscovered the forest.

Dr. Art Medeiros, program manager for the Auwahi Forest Restoration Project, was one of those biologists. “Puʻuokali is amazing. It’s almost the only place from Makawao to Kaupō that looks like it did when Hawaiians were the only people here.” Wiliwili, lama, naio, koaiʻa, and ʻohe are the dominant trees of this forest – these plants were essential for early Polynesians but are virtually unknown today. Dryland Hawaiian forests are the most diverse of Hawaiian forests, yet they are virtually lost: an estimated 90 to 95% of dryland forest is gone. What remains is critical: 25% of endangered Hawaiian plant species are found in these tiny refugia.

In July of 2018, Byron Stevens of the Hawaiʻi Natural Area Reserves System passed over Puʻuokali in a helicopter and saw something that didn’t belong: a two- to four-foot-tall bunchgrass with wiry leaves and purple bottle-brush flowers. Fountain grass. He sounded the alarm to multiple conservation organizations.

Fountain grass starting to invade the sacred grounds of Puʻuokali on Maui. This area is one of the few remaining places that show how Hawaiʻi looked prior to western contact.

Fountain grass is an invasive weed rarely found on Maui. Native to North Africa, it’s targeted for eradication by the Maui Invasive Species Committee. The drought-tolerant grass is able to survive in some of Hawaiʻi’s driest areas; it poses a serious threat to native dryland forest. While rare on Maui, the alien grass now covers much of the leeward coast of Hawaiʻi Island. Introduced as an ornamental in the early 1900s, fountain grass has completely transformed the Kona side of Hawaiʻi Island, turning what was once bare lava with patches of native forest into fields of grass.

“Introduced as an ornamental in the early 1900s, fountain grass has completely transformed the Kona side of Hawaiʻi Island, turning what was once bare lava with patches of native forest into fields of grass.”

Dominating arid, bare lava is one thing, but this wiry bunchgrass can also advance into intact forest, in part because it survives brushfires. Fountain grass is fire-adapted; it can regrow after flames pass over then quickly flowers and set seeds to recolonize the area. In contrast, Hawaiian forests are not adapted to fires—native plants generally donʻt survive. Fountain grass is notorious for fueling and increasing fire. At one site on Hawaiʻi Island, fountain grass (ignited by humans) has increased fire frequency from once every 500-1,000 years to once every 6-8 years.

“Fountain grass is a direct threat to the Maui County sanctuary forests such as Puʻuokali, says Medeiros. Though surrounding areas have burned, Puʻuokali has not had any wildfire, hence why so much remains. This hidden forest survived over the years partly because the surrounding landscape was so barren. There was no fuel for brushfires, and less incentive for goats and deer to cross the cinder to reach the crater. “The last refuges [of dryland forest] are in these rocky areas,” Medeiros explains. The intrusion of fountain grass changes that.

Fountain grass is almost never found on Maui, but is extremely widespread on the leeward side of Hawaii island, where it has transformed the landscape and continues to spread. Any sightings of this invasive bunchgrass should be reported — identified by its purple bottle-brush flowers that turn white as they age. MISC file photo

With that in mind, crews from multiple organizations – Auwahi Restoration Group, Haleakalā Ranch, the Maui Invasive Species Committee, and the Plant Extinction Prevention Program – came together to remove over 1,000 fountain grass plants from Puʻuokali. Completing the work will take several years. Grass seeds cover the ground and recent rains will bring a flush of seedlings. But now that the infestation has been detected, it can be managed and eradicated.

You can help. Fountain grass is often used as an ornamental landscaping plant, and people sometimes plant it on Maui by accident. Seeds can be unwittingly transported interisland on hunting or golf gear. If you see fountain grass, take a photo and report it. You can contact MISC directly at 573-MISC (6471) or the statewide pest hotline at 643-PEST, or 643PEST.org.

Lissa Strohecker is the public relations and education specialist for the Maui Invasive Species Committee. She holds a biological sciences degree from Montana State University. Kia’i Moku, “Guarding the Island,” is prepared by the Maui Invasive Species Committee to provide information on protecting the island from invasive plants and animals that can threaten the island’s environment, economy, and quality of life.

This article was originally published in the Maui News on September 12th, 2018, as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Read more Kiaʻi Moku articles. Find more information about fountain grass:

Species profile: Fountain grass
Report suspected populations of fountain grass: 643PEST.org

Pines threaten Haleakalā

Posted on November 16, 2016 by Lissa Strohecker

Forest Starr removes a pine sapling as part of the effort to protect Haleakala Crater. Only few species of pines are invading Haleakalā: Pinus radiata (Monterey pine), Pinus patula (Mexican weeping pine), and Pinus pinaster (maritime pine). Photo courtesy of Forest and Kim Starr

Haleakalā Crater is a rainbow of cinder, unlike anyplace else on earth. The result of millions of years of eruption of a stop and start volcano. At its greatest height, Haleakalā reached between 13,500 to 14,500 feet into the sky. When eruptions paused, the wind and rain went to work sculpting the crater, then it erupted again. Today, this history is laid bare for all to see. The plants and animals that live in this environment equal the geology, both in rarity and beauty. Haleakalā National Park is home to more threatened and endangered species than any other national park in the United States.

“…the tie-ribs of earth lay bare before us. It was a workshop of nature still cluttered with the raw beginnings of world-making.” wrote Jack London about Haleakalā Crater. Photo by Forest and Kim Starr.

It’s not only the natural history that makes Haleakalā Crater unique. It ranks as the quietest place on earth, a notable distinction in our busy bustling world. For the most part, Haleakalā Crater today would be recognizable as the same landscape, with most of the same vegetation, as it appeared to the early Polynesians that honored the crater as a the Wao Akua, realm of the gods; the same erosional depression that inspired Jack London to write “the tie-ribs of earth lay bare before us. It was a workshop of nature still cluttered with the raw beginnings of world-making.”

Few places remain so untouched today. Keeping the crater in a comparatively pristine state takes many hands. Miles of fence keep out the feral pigs and goats that once trampled the crater, but invaders still come, as seeds from invasive plants blown on the wind or hitchhiking on vehicles and clothing.

Today, the sanctuary of Haleakalā, the workshop of nature, is at risk of being lost underneath a blanket of pine trees. “Removing pines from the crater is our highest priority in terms of invasive plant control work in Haleakalā National Park,” explains Woody Mallinson, the Natural Resource Program Manager at Haleakalā National Park.

Kim Starr stands by a pine sapling in Haleakalā Crater. If these pines are not removed they will take over, leaving no room for the silversword and other plants an animals found only on Haleakalā. Photo by Forest and Kim Starr

Between 1910 and the 1940’s, well-intentioned territorial foresters planted pines on windward and leeward sides of Haleakalā, just west of the Koʻolau Gap, in Hosmer’s grove, and Polipoli to stop erosion and provide timber. A handful of those pine species turned out to be invasive. Over the next century they became increasingly widespread. Occasionally seeds found a way into Haleakalā, growing in the cinder soil. Park crews routinely removed them. They pulled 22 pines between 1982 and 2006.

But in 2007, a natural disaster spurred an explosion in pine seed germination. The pine plantation in Polipoli caught fire and the resulting flames burned over 600-acres on the southwestern slope of Haleakalā. The fire fighters who fought the blaze hadn’t seen anything like it in Hawaiʻi. Wildfires here typically spark in grasslands, but a summer drought left the forest of Polipoli primed for a forest fire. Pines, rich in natural oils and pitch, burn hot and flames blazed high above Kula.

The heat of the fire triggered the release of millions of pine seeds from inside their waxy cones. This natural response helps pines recolonize after a forest fire. It’s highly effective, and it has helped the pines colonize Haleakalā as well. Pines can be relatively slow growing, but they’ve managed to take over 2,200 acres of cliff walls and have the potential to invade about 18,000 acres of the Park. Since 2007, crews removed over 81,000 pines from the crater floor and walls, they estimate another 3,500 pines are creeping up the steep cliffs of the crater.

Pine saplings cascade down the rim of Haleakalā Crater. A 2007 forest fire in the Polipoli pne plantation spurred the germination of hundreds of thousands of pine seeds, carried on the wind into the crater. Photo by Forest and Kim Starr.

Pine saplings cascade down the rim of Haleakalā Crater. A 2007 forest fire in the Polipoli pine plantation spurred the germination of hundreds of thousands of pine seeds, carried on the wind into the crater. “If left unaddressed, the entire crater could be converted into a pine forest” Explains Woody Mallinson. Photo by Forest and Kim Starr.

“If left unaddressed, the entire crater could be converted into a pine forest. The result would be a landscape unrecognizable as compared to what we know today, with little to no habitat for endemic and endangered species. It would be a catastrophic ecosystem displacement,” explains Mallinson.

If the crater were to become a pine forest, the likelihood of future fires would increase. The combination of the dry arid climate, frequent winds, and fuel-rich pines could combine with disastrous results, especially for native Hawaiian species not adapted to fire.

Haleakalā National Park, in partnership with The Nature Conservancy, East Maui Watershed Partnership, Hawaiʻi Department of Land and Natural Resources and other conservation agencies are working to remove the pines, both inside and out of the park boundaries. Their efforts are helping to reduce the density of pines and protect Haleakalā.

You can participate. Join volunteer groups working with the Friends of Haleakalā on trips to remove pine trees from around Haleakalā Crater. Check their website for more information: www.fhnp.org

Lissa Fox Strohecker is the public relations and education specialist for the Maui Invasive Species Committee. She holds a biological sciences degree from Montana State University. Kia’i Moku, “Guarding the Island,” is prepared by the Maui Invasive Species Committee to provide information on protecting the island from invasive plants and animals that can threaten the island’s environment, economy and quality of life.

Originally published in the Maui News on August 14th, 2016 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Glycine got ya down?

Posted on May 11, 2016 by Lissa Strohecker

Tips & Tricks for Common Pests – Glycine

glycine smothering habit ulupalakua -fks

Glycine blankets the roadsides of Ulupalakua and parts of Kula. Photo by Forest and Kim Starr

With all the rain last summer, many upcountry Maui homeowners spent the winter battling a twining green vine. Glycine, most commonly known from ʻUlupalakua and Kanaio, is the vine that blankets fences and rock walls and hangs from trees. It primarily grows in open sunny areas. When the rains come, a flush of seedlings follows.

Related to the common soybean, glycine (Neonotonia wightii) is a nutrient-rich nitrogen fixer. The Soil Conservation Service introduced this tropical vine to Hawai’i after a massive kikuyu grass dieback in the 1970s. Glycine was widely recommended for pasture improvement and forage. Grazing animals love it, but in their absence, the vine can take over.

Glycine seeds remain viable for years in the soil. Photo by Forest and Kim Starr.

Diana Crow is the Native Plant Project and Nursery Manager for ʻUlupalakua Ranch, a position that has necessitated she be adept at glycine control. Her advice for controlling the weed:

Biological: Animals love glycine – a pet goat would be happy to help you.
Mechanical: First, cut all the vines back from the tree or bush you are trying to save and loosen the vine along the trunk and branches to stop the vine from strangling the tree. Follow the vine down to the ground and pull or cut out the roots. If any root is left in the ground you will have to check for resprouts and cut it back until the reserves in the root are exhausted. If the plant has been there for a while, there will be a seedbank. Flushes of seedlings can be controlled by putting down boards, black plastic, or anything that blocks water and sunlight until seedlings die, usually within a month or two. Solarization of the seedbank may be possible in sunny areas. (Solarization is a method of reducing the seedbank by covering the soil with clear plastic until the sun heats it to a point that kills the seeds. Check for resources online.)
Chemical: Apply herbicide directly to the cut trunk of a vine. Make sure to use a broad-spectrum herbicide, one intended for broadleaf plants that is effective on legumes. The College of Tropical Agriculture and Human Resources recommends a foliar spray of 2% triclopyr amine with a surfactant in the “Weeds of Pastures and Natural Areas.”
Cultural: Glycine thrives with water; reducing irrigation or sprinklers may help, but not in the presence of seasonal rains. The seedpods will twist when ripe and dry, shooting seeds yards away. Glycine’s seed bank seems to last years, as Diana still has seedlings coming up from an area where a plant was removed 8 years ago. Her advice: DON’T LET IT SEED!

We recommend using an Integrated Pest Management approach to managing weed pests and the information provided here reflects that perspective.

Photos of glycine courtesy of Forest and Kim Starr

Deck your hall with boughs of locally harvested plants

Posted on February 10, 2016 by Lissa Strohecker

Join the Friends of Haleakalā for their annual pine pull – a chance to remove invasives and take home some locally harvested holiday greenery. Photo by Matt Wordeman.

Friends' 2014 pine pull - down the hill - Matt wordeman

Collecting pine trees Maui style. Though the snow may be lacking it still warms the heart. Photo by Matt Wordeman

Deck the halls with boughs of….holly? ‘Tis the season to decorate your hale with holiday wreaths, sprigs, and boughs.

Fresh greenery, seeds, and flowers are as much or more a part of this season as pretty paper and bows. Using plants to adorn homes during the winter solstice is a tradition that goes back to ancient times, as many cultures celebrated the return of the sun. Egyptians filled their homes with palms to celebrate the recovery of Ra, their sun god, from the illness that left the days shorter. Early Romans brought fir trees inside during their solstice feast of Saturnalia, honoring Saturn, the god of agriculture. Vikings honored the sun god Balder with pine boughs, and the Druids decorated their temples with evergreen boughs symbolizing everlasting life. Evergreens hold particular significance as they remain fresh throughout the year, no matter the climate.

Traditionally, all of these decorative plants were collected locally. It’s only in today’s era of globalization that our traditions are tied to imported plants and food. This year, consider revising your definition of traditional and decorate with locally grown plants. In doing so, you share your love of Hawaiʻi and help protect our island way of life for future generations.

Pine trees and garlands:
Few decorations are as iconic as the Christmas tree. But almost every year, agricultural inspectors hold and treat or even reject shipments of pines from the mainland because they contain hitchhiking pest species that threaten Hawaiʻi. Each tree is shaken to check for unwanted pests: slugs and yellow jackets are not uncommon, and in 2010 salamanders and Pacific tree frogs were found. The Vespula wasp made its way to our islands via shipments of Christmas trees in the 1970s.

Alternatives: If you consider evergreens a necessary ingredient for the holidays, you’ll be pleased to know there are locally grown pines available, for sale or for harvest. Each year groups like Friends of Haleakala National Park remove invasive pines from the slopes of Haleakala. Volunteer with them and you and your family can get a free tree. If you missed the December 12^th event this year, mark your calendar to check the Friends’ website next year: www.fhnp.org

Wreaths:
A beautiful wreath of fresh foliage welcoming people to your home is a great way to set the tone for the holiday. Whether you create your own or purchase one ready-made, make sure the fresh decorations on your wreath are locally sourced. If you are using the reproductive parts of a plant (seeds or berries) it’s especially important to ensure that you are not helping spread an invasive pest or disease. For example, pampas grass has beautiful feathery plumes, but it’s a pest that the Maui Invasive Species Committee works to remove from Maui. Each plume is filled with thousands of wind-blown seeds that can compromise Maui’s watershed – not the message you want to send from your front door.

Alternatives: Locally grown pines, proteas, succulents, and herbs can be used to create beautiful and sturdy wreaths. If you need a little guidance, several organizations and local businesses have wreath making classes during December; Aliʻi Kula Lavender Farm still has classes so you can create a wreath in time for Christmas: www.aliikulalavender.com. Locally made wreaths are often available at farmers’ markets.

Houseplants and other vegetation:
Poinsettias are a holiday stable, and a houseplant or orchid is a great gift for the person who has everything. Purchasing plants from local growers lessens the likelihood that you’ll be giving an unintended gift.

Alternatives: Every year the Agricultural and Natural Resources Class at the University of Hawaiʻi Maui College grows poinsettias to sell as a fundraiser. Check the paper or the Facebook page for exact dates. Consider giving a native plant grown on Maui; ask your garden shop where the plants are grown.

Ancient and modern Hawaiians celebrate Makahiki at this time of year, a time of peace, feasting and festival, celebrating the prosperity of the land. It’s a time of family and gathering together, a time of creating and passing along traditions. This year, celebrate the prosperity of the islands and protect it for future generations. Hauʻoli makahiki hou from all of us at the Maui Invasive Species Committee.

Kia’i Moku, “Guarding the Island,” is prepared by the Maui Invasive Species Committee to provide information on protecting the island from invasive plants and animals that can threaten the island’s environment, economy and quality of life.

Written by Lissa Strohecker. Originally published in the Maui News on December 13th, 2015 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Pigs and Pampas

Posted on January 12, 2016 by Lissa Strohecker

A spike camp in the East Maui rainforest. Camps like these are home for the crews working to protect and remove invasive species in this remote section of Maui. Photo by Maui Invasive Species Committee.

At about 4000’ elevation, just east of Koʻolau Gap above Keʻanae on the island of Maui, a four foot tall hogwire fence stretches from the cliff edge across ravines and gulches to the next cliff edge at Honomanū. This fence and a rudimentary shelter are the only indications that people have ever set foot up here. It’s a unique section of the mountain; the soil is slow to drain and the ground is boot-sucking wet, even in summer. Clouds drift through the branches of ‘ōhiʻa all day long, leaving everything soggy, though rain may not actually fall.

The fence protects this section of East Maui rainforest from the feral pigs that roam farther down the mountain, but that was not always the case. Pigs are not native to Hawaiʻi. But until a decade ago, they wandered freely up here, miles from the nearest road. Though they weren’t plentiful, they did plenty of damage as they rooted through the soil, leaving patches of bare dirt scattered over hundreds of acres.

Pigs were not the only invaders. Pampas grass, an ornamental once planted in upcountry residents’ yards, sprang up throughout this forest. The tall, clumping grass sends up a feather plume filled with seeds that travel on the wind for miles. Pampas seeds occasionally germinate in mossy tree trunks, but their preferred conditions are bare soil with regular moisture. Pigs in Honomanū cleared and prepped the forest floor for pampas grass. Once a few plants became established, conditions were ideal for spreading. They quickly began to outcompete native species.

Far from the landscaped yards, pampas grass flourishes in the East Maui rainforest, benefiting from the disturbance created by another invader, pigs. Photo by Maui Invasive Species Committee.

Of course it’s not just pampas grass that benefits from the disturbance created by pigs. Many notorious invasives spread into upland forest with the help of wild pigs–strawberry guava and banana poka, for instance. Pigs carry the seeds in their gut, then deposit them with a pile of fertilizer. Their rooting habits create wallows for mosquitoes that spread diseases to native birds. Pigs knock down native hāpu;u tree ferns to reach a starchy meal in the trunk, in the process destroying the fern’s native seedling “nursery.”

In Hawaiʻi, pig impacts are magnified. The rototilling action of a pig is a completely alien force in a forest that evolved for millions of years without a hoof or tusk. “Disturbances to the forest floor from pigs and weed problems go hand in hand,” says Dan Eisenberg, who manages the East Maui Watershed Partnership. His organization built the fence east of Koʻolau Gap and other fences that protect high elevation forest on East Maui.

Fencing out pigs and other hooved invaders is the first step in restoring native Hawaiian ecosystems. When these tusked tillers are removed, plants do better–regardless of whether they are native or introduced. Common native plants recover in under a decade, but rare species often take much longer, and face competition from exotics that became established prior to pig removal. “Invasive plant species are so fast growing compared to most plants in the native forest that our unique native species don’t have a chance without responsible management,” explains Eisenberg.

As pigs dig for roots and grubs, they rototill the soil. Disturbance and bare soil creates gaps in the forest floor opening it up for invasive plants. Photo courtesy of East Maui Watershed Partnership

The East Maui Watershed Partnership completed the fence in Honomanū in 2006, about the same time, crews from the Maui Invasive Species Committee switched from trying to spray pampas from the air to camping in the field while removing pampas on the ground. Weeklong work trips are a less soggy ordeal since the team built a tent platform. When crews find pampas hiding amongst the native foliage, they cut off any seed heads, bury them inside the plant, and then kill the pesky grass in place, being careful to not disturb the soil and open up an area for seeds to germinate again.

During the summer of 2014, crews found and controlled 87 pampas plants, only 4 of which were capable of making seeds. Compare this with the summer of 2008, when crews found 2,029 plants. Pampas grass seeds don’t remain viable for long, perhaps as short as 6 months. Soon the East Maui pampas may disappear entirely and the forest can rebound.

Read more about the efforts to remove pigs and pampas grass on East Maui at www.eastmauiwatershed.org and www.mauiisc.org.

Written by Lissa Strohecker. Originally published in the Maui News on October 11th, 2015 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

How did that get here? Strange plants atop Haleakalā

Posted on November 5, 2015 by Lissa Strohecker

High atop Haleakalā winds whip across the summit, frost crystals sparkle in the morning sun – melting as the day progresses. But even in this harsh landscape, native plants and animals can thrive – and so can invasive species.

Pineapple chamomile, a native to the Northwestern US and other places, may have been carried to Haleakala summit via a seed on a boot. Photo courtesy of Forest and Kim Starr

One of these invaders is pineapple chamomile–about as authentically Hawaiian as a coconut bikini. But here it is, growing just outside the parking lot of the summit viewing area at 10,032 feet, comfortable in the extreme, high-elevation climate of a Pacific volcano. It’s no wonder; this aromatic herb’s home range includes a wide sampling of climates and terrains: Western North America from Baja through British Columbia to Alaska, the Russian Far East, and Hokkaido, Japan.

The weed likely hitched a ride up to Haleakalā on a tourist, as seed on a shoe or jacket, brushed off as the unwitting carrier geared up for the crisp mountain climate. This is not unusual. Without realizing it, people carry little hitchhiking seeds throughout the world in their socks and gear.

Pineapple chamomile is a relative of the chamomile in your tea bag and can also be brewed up. This small shrub thrives in disturbed areas with gravelly soil and full sun, just like Haleakalā. The fern-like leaves are somewhat sticky and the leaves and flowers smell like pineapple when crushed. It has a weedy reputation in many places, springing up across the United States.

Forest and Kim Starr do regular botanical surveys on Halakalā summit. Not a bad “office.” Photo courtesy of Forest and Kim Starr.

Isolated ecosystems are populated by a relatively small number of plants and animal species, generally highly specialized to survive. But introduced plants or animals often come from diverse environments, populated by many different species, and have developed strategies to compete and survive in their native range. When a plant or animal is introduced to an isolated ecosystem, like an island, it arrives with a competitive advantage the native species may not have.

In Antarctica, researchers spent 2007-2008 collecting seeds from tourists’ bags and clothing. They found that on average a visitor to Antarctica carried 9.5 seeds along with them. An estimated 33,054 tourists visited the frozen continent during the study period, demonstrating how many seeds could be introduced. Though not all seeds would germinate or survive in their new home, the researchers estimated that as many as 61% of the seeds carried to the Antarctic came from a part of the world with a climate similar enough that they could pose an invasion risk. Researchers working in Antarctica carried even more seeds on their clothing and gear though they visited Antarctica in much lower numbers.

The Starrs also found Henbit, a non-native mint, during surveys. Photo courtesy of Forest and Kim Starr

On Haleakalā, botanists Forest and Kim Starr found pineapple chamomile, henbit (a weedy member of the mint family common in North America), and a handful of other non-native plants during their surveys of the high-traffic areas of Haleakalā National Park, a project done in conjunction with the University of Hawaiʻi and National Park Service.

When the Starrs find a single weed or very few in a small area, they can remove the unwanted plants easily. Eradicating an invasive species at this stage of invasion is highly effective, second only to preventing its arrival in the first place.

If the plant has gone to seed, eliminating the resulting seedlings may take multiple visits. Pineapple chamomile has proven a little more persistent than some of the other plants. It produced seeds before the Starrs first found it, so they keep finding a few scattered plants.

Boots are a notoriously common vector for seeds of invasive species.

The Starrs are careful not to carry hitchhikers when they survey sensitive ecosystems. Follow their lead. Take a minute to brush off your boots, clothing, and gear before traveling or visiting pristine areas. You can help prevent new species from invading in the areas you frequent, whether your expeditions take you to Antarctica, Haleakalā, or the beach.

Written by Lissa Strohecker. Originally published in the Maui News on September 13th, 2015 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Clearing the weeds for albatross

Posted on October 15, 2015 by Lissa Strohecker

Space is at a premium for nesting Laysan albatross on Midway atoll. Removal of the invasive golden crownbeard may have helped provide more nesting area. Photo by Forest and Kim Starr

Midway Atoll has gone to the birds. Every year 3 million seabirds flock to 1,500 acres of land 1200 miles northwest of Honolulu. The former Naval Air Station is also the most remote seabird colony in the world, home to 1.5 million Laysan albatross (65% of the global population) as well as 19 other species of seabirds – shearwaters, terns, boobies, noddies, curlews, and most recently, the translocated Laysan duck. But albatross and their feathered kin were not nearly as plentiful some years ago.

Hungry rats that devoured seabird eggs were the most obvious cause, but after rats were eradicated in the 1990s and seabird populations began to rebound, biologists were concerned that the birds’ continued recovery was blocked – literally – by an invasive plant.

Drought tolerant and fast-growing golden crownbeard, Verbesina encelioides, thrives in the harsh tropical sun on Midway Atoll. This yellow-flowered daisy-like plant grows head-high, creating a dense barricade that seabirds can’t walk through, much less nest in. Photo by Forest and Kim Starr.

Golden crownbeard, or Verbesina encelioides, is an aggressive annual herb from the desert southwest. This yellow-flowered daisy-like plant grows head-high, creating a dense barricade that seabirds can’t walk through, much less nest in. For the birds who do find a place to lay their eggs, the tangle of flowering stems limit airflow to nests, leaving chicks vulnerable to dehydration and death.

Like all invasive species in Hawaiʻi, golden crownbeard made the long journey to the Islands with the help of people. In 1903, the Commercial Pacific Cable Company was building a trans-Pacific cable and Midway was one of three intermediate stations, along with Honolulu and Guam. To transform a seabird colony into the semi-permanent home of a handful of cable operators, the Company constructed four two-story concrete buildings and shipped over 9,000 tons of soil from Hawaiʻi and Guam so the new human residents could plant shade trees and grow food. It’s possible that seeds of golden crownbeard were mixed in the soil or on equipment, but it’s equally plausible that the new islanders or later residents stationed there with the military planted this North American native as a reminder of home.

Regardless of how it arrived, golden crownbeard flourished in the harsh tropical sun. This weed is the most invasive of the more than 225 non-native plants on the low-elevation islands of Midway. It’s very drought tolerant and needs only a monthly sprinkling once the roots are established. This yellow scourge goes from seedling to flowering plant within months of germination and a single plant can produce 350 seeds.

Native Cyperus grass is replanted on Midway after invasive species are removed. The native grasses allow for more airflow to the nest as well as more space to build nests. In 2012-2013 Laysan and black-footed albatross nested at near-record levels. Photo by Forest and Kim Starr

Only a few years ago, golden crownbeard covered 80 percent of the three islands that make up Midway. In the late 1990s, the US Fish and Wildlife Service began removing the head high plants. With more funding the work pace quickened; crews head out almost daily to spray this pest. Tractors or heavy equipment can’t be used with so many seabirds above and below ground, so hand spraying is the way to go. All this work is starting to pay off.

Golden crownbeard will hopefully be eradicated from the smaller Eastern Island and Spit Islands by early 2017. The last batch of seedlings will be removed from the bigger Sand Island by 2018. As the invader is knocked back, the native grasses and coastal plants are being replanted to stabilize dunes and protect the reef.

The seabirds seem pleased with the efforts to restore their habitat. In 2012-2013, Laysan and black-footed albatross nested at near-record levels, though biologists won’t know if this increase is a result of the golden crownbeard removal efforts for several more years.

To learn more about golden crownbeard and the amazing birds on Midway visit the Friends of Midway Atoll website: www.friendsofmidway.org or the Papahānaumokuākea website: www.papahanaumokuakea.gov

Originally published in the Maui News, August 9th, 2015 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

A Haʻiku gulch full of suprises

Posted on July 24, 2015 by Lissa Strohecker

The prickly seed ponds on this climbing vine led to a concernd Ha'iku resident reporting it to MISC as a potential invader. Turns out it is a native plant, Mucuna sloanei. Photo by Hank Oppenheimer

The prickly seed pods on this climbing vine led to a concerned Ha’iku resident reporting it to MISC as a potential invader. Turns out it is a native plant, Mucuna sloanei. Photo by Hank Oppenheimer

“Anything that bristly has got to be invasive,” said the Haʻiku resident who reported a vine that she found in the gulch on her family property. She called the Maui Invasive Species Committee (MISC) when neither she nor her relatives could identify the strange climber with seedpods covered in fiberglass-like hairs. No one in the family had noticed it before and they had worked or played in the gulch since small-kid times. She collected a specimen, prickly seedpods and all, and brought it into the MISC office.

Though bristly, it turned out not to be an invasive species after all. The unusual creeper was a native plant once widespread in low elevations on Maui and other Hawaiian Islands. Commonly known as seabean, botanists call it Mucuna sloanei.

Mucuna comes in two varieties: sloanei, indigenous to Hawaiʻi; and persericea, endemic to windward East Maui and found nowhere else in the world. There are only a few of the persericea plants left. Because of the rarity of the persericea variety, and the damage caused by pigs and cattle to its habitat, the vine was recently listed as endangered by the U.S Fish & Wildlife Service. The possibility that it could be thriving in a Haʻiku gulch, only a stone’s throw from the Haʻiku Marketplace, was therefore pretty exciting. But it takes an expert to know the difference between the two varieties and Hank Oppenheimer fits the bill.

Oppenheimer is the Maui Nui Coordinator for the Plant Extinction Prevention Program (PEPP), a Pacific Cooperative Studies Unit project that works to protect the most rare and threatened plants in Hawaiʻi. Throughout the state, a handful of people like Oppenheimer and technician Keahi Bustamente hike deep into remote forests, scaling cliffs and doing whatever they can to prevent the rarest species’ extinction. This includes collecting seeds from rare Hawaiian plants, propagating them in greenhouses, and then outplanting the precious plants in protected habitat.

For plants, garnering listing as a PEPP species of interest is a mixed blessing; it means there are less than 50 individuals left in the wild. Oppenheimer is investigating the distribution of persericea to determine if it should be included with the other 236 PEPP targets.

Finding the native Mucuna sloanei was a pleasant surprise. Photo by Hank Oppenheimer

Oppenheimer and Bustamente headed to the Ha’iku gulch. The vine turned out to be the more common sloanei, but Oppenheimer was still excited. “It was really interesting to see Mucuna in a place like that,” he said. Most of the habitat for Mucuna has been turned into pasture, farmland, or long ago taken over by invasive plants.

But as the team was leaving the gulch, they made a troubling discovery. Bustamente noticed an unusual plant with massive 2-3 foot long leaves, purple on the underside. He knew it instantly as miconia. This notorious pest and MISC target was certainly out of place; miconia is primarily between Keʻanae and Hāna. The discovery marks the westernmost naturally occurring plant in recent history.

So when the Haʻiku resident reported what she thought was an invasive vine, she actually helped uncover a relatively rare native species as well as one of the most invasive plants in Hawaiʻi. A great example of the more you look, the more you find.

Can you spot the miconia plant? The characteristic large leaves with purple undersides cued botanists into this plant’s presence in a Ha’iku Gulch. MISC file photo

To learn more about the Plant Extinction Prevention Program, visit the website www.pepphi.org. And if you think you may have Mucuna on your property, contact Hank Oppenheimer at henryo@hawaii.edu. If you would like help identifying an unusual plant, native or not, you can find a number of resources available online, including the Flikr site “Hawaii Plant ID,” curated by some of the state’s best botanists, or you can call MISC at 573-6472, particularly if you think you’ve found miconia.

Originally published in the Maui News, April 12th, 2015 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.

Christmas berry’s unwelcome presence

Posted on March 4, 2015 by Lissa Strohecker

Christmas berry, is also a pest in the pastures of Hawaii. Photo by Forest and Kim Starr

Covered in glossy green leaves and bedecked with red berries, the invasive shrub, Schinus terebinthifolius, is commonly known by the appropriate moniker of Christmas berry. But the presence of this Brazilian species in Hawaiʻi hardly inspires festive spirit in the hearts of island resource managers.

Christmas berry was introduced to Hawaiʻi sometime before 1911 to spruce up yards. Before long this hardy shrub escaped backyards and began to spread across Hawaiʻi . Drought-tolerant, fire-resistant, and even capable of withstanding flooding for up to six months, Christmas berry thrives in dry and mesic climate zones across the archipelago.

The Hawaiian mesic forest found in Kaupō Gap is one of the most diverse ecosytems found in the state. Photo by Woody Mallinsin

The mesic forest zone is characterized by a moderate amount of rain and no extended droughts—ideal conditions for many plants. Hawaiian mesic forests are one of the most varied ecosystems in the islands, home to a diverse assemblage of endemic plants found nowhere else on earth. Dominated by koa, this forest is also home to sandalwood, māmane, tree lobelias, and species of native hibiscus. This is critical habitat for native insects, birds, and the ʻōpeʻapeʻa, or Hawaiian hoary bat, yet the mesic forest is one of the most threatened and consequently most rare ecosystems

Today, Maui’s mesic zone is where the farmland, pasture, and houses that make up Makawao, Kula, and ʻUlupalakua can be found. Unfortunately, native forest not lost to development is being gobbled up by feral deer and goats and infested by fast-growing, non-native weeds, such as Christmas berry.

Christmas berry, is also a pest in the pastures of Hawaii. Photo by Forest and Kim Starr

Crews from Haleakalā National Park are trying to reverse that trend. After fencing goats out of Kaupō Gap, crews began removing some of the worst invasive plants in the area. Capable of establishing in shady conditions and releasing chemicals that inhibit the growth of other plants, Christmas berry is one of the most significant threats to endangered plants.

Christmas berry is not only a pest to pristine native forest; it has a well-deserved reputation as a pasture weed. Cattle pass over the turpentine-scented leaves, but birds savor the plentiful seeds, helping to spread the plant to new areas. With high germination rates, Christmas berry quickly chokes out pastureland.

Christmas berry is also a problem in Florida where it’s known as Brazilian pepper. This invader has taken over an estimated 700,000 acres, threatening riparian areas and unique ecosystems of Everglades National Park.

Like other established invaders, Christmas berry is a target for biological control. With hopes of checking the spread and vigor if Christmas berry, the Hawaiʻi Department of Agriculture introduced several insects that attack the plant in its native range In the 1950s and 60s the Hawaiʻi Department of Agriculture brought in three insects, a beetle and two moths from Brazil. The beetle and one moth became established but have only caused minor damage. Another beetle, an unintentional import from Australia, attacks the plant’s seeds. Currently, research is underway on the efficacy of a sawfly, a wasp-like insect that feeds on the leaves of the plant, for biological control in Hawaiʻi.

You can help. If you live near sensitive natural areas, please do not plant Christmas berry. You can find information from the University of Hawaiʻi s College of Tropical Agriculture and Human Resources about how to control Christmas berry at ww.ctahr.hawaii.edu/invweed/WeedsHI/W_Schinus_terebinthifolius.pdf

A chance to see some of the last remaining intact mesic forest in Hawaiʻi is only a hike away on the Kaupō trail. Before you go you, learn more about the plant communities of Kaupō through the Haleakalā National Park website: www.nps.gov/hale/naturescience/upload/Kaupo-Gap-Mesic-Forest-2.pdf

By Lissa Fox Strohecker. Originally published in the Maui News, December 14th, 2014 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee

Invasive plants=Less water

Posted on June 27, 2014 by Lissa Strohecker

This rainforest, in Puu Kukui on West Maui, is an example of an open canopy rainforest typical of native rainforest in Hawaii. This forest acts like a ‘sponge,’ absorbing water from rain and gently releasing to recharge streams and aquifers. MISC file photo

When rain falls from the sky by the bucket-load it can be tempting to take water for granted, but the trip from raincloud to tap relies on effective, functioning natural systems. In Hawai‘i, alien plants disrupt the forest’s ability to capture water.

Water follows a cycle through the environment. Water over the ocean evaporates becoming atmospheric moister, as it travels over land it condenses into clouds, falling to Earth as rain or fog drip. Once on the ground, water has three paths: 1) it’s taken up by plants that use it to move nutrients through their cells, then return it to the atmosphere via transpiration; 2) it fills streams, lakes and rivers, eventually returning to the ocean–minus what was used for irrigation or lost through evaporation; or 3) it seeps through the soil into underground pools called aquifers. These aquifers supply most of the water we use to drink, bathe, and grow our food.

Forests have evolved differently to take advantage of prevailing water cycles in their regions. In South America and Africa the greatest diversity of plants is found up in the canopy. In Hawai‘i most plant species are found in the lower third of the forest, closer to the forest floor. Hawaiian understory plants need sunlight filtering through an open canopy. Koa and ‘ōh‘ia, the dominant Hawaiian canopy trees, grow in such a way that light reaches the shrubs and groundcover below.

Koa and ‘ōh‘ia pull water from passing clouds as fog drip; the curved leaves of koa provide surface area to collect moisture from clouds and channel it down leaf tips to the forest floor. Spongy plants on ‘ōh‘ia branches and trunks absorb moisture from passing clouds. Alien species disrupt the system.

Strawberry guava, Psidium cattleanium, has invaded Hawaiian rainforests, growing so dense and so

Strawberry guava invaded forest in Makawao Forest Reserve

The invasive tree strawberry guava chokes out native plants. As it sheds bark, strawberry guava provides no habitat for the plants growing on the trunks of native species. Photo courtesy of Forest and Kim Starr.

fast that it chokes out other plants. A strawberry-guava-invaded forest captures water differently than our native forests. In Hawai‘i Volcanoes National Park researchers found that a forest dominated by strawberry guava delivered less water to the forest floor than an intact native rainforest. Researchers noticed several differences between the two forest types: more rain ran down the stems of strawberry guava than ‘ōh‘ia but less water was pulled from the passing clouds. This could result from structural differences. ‘Ōh‘ia have aerial roots and furrowed bark carpeted with mosses and small plants called epiphytes. The epiphytes and aerial roots soak up water from passing clouds. Strawberry guava bark is smooth and regularly shed; few plants grow on its trunk and branches.

Other invasive species disrupt the water cycle by sheer size—leaf size. Miconia trees with three-foot long leaves sweep into the forest, stealing light from the understory and transforming it into darkened forest, the soil bare but for miconia seedlings. As another researcher on Hawai‘i Island discovered, the huge leaves are more than just light-hogs. They collect water as if they were huge tarps, and, as anyone who has stood near the edge of a tarp in a rainstorm knows, it’s only a matter of time until the water

The forest floor under a miconia invasion is bare, often with exposed roots. Not a good sign for water collection. MISC file photo

dumps down. The drops running off of miconia turn out to be the largest drops ever measured. Larger drops hit the ground harder, and where miconia has smothered the understory, those drops fall on bare soil. Huge drops compact soil particles, preventing water from seeping down to aquifers, instead causing it to run off, carrying topsoil into streams and eventually the ocean where it can smother coral reefs.

These are only some of the ways invasive plants alter the forest’s ability to capture water. Water-hungry plants like Himalayan ginger pave the forest floor in tough roots. Huge trees like eucalyptus require more water to carry nutrients to their crowns than smaller trees. Unfortunately, the list goes on. Healthy forests mean reliable sources of water. Keeping invasive plants out of native forests is one way to help keep the water flowing from raincloud to tap

By Lissa Fox Strohecker. Originally published in the Maui News, March 11th, 2012 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee