Vol. 24, No. 2 Summer 2016 Cal-IPC News Protecting ’s Environment and Economy from Invasive Plants

Newsletter of the California Invasive Plant Council

Celebrating park stewardship

Testing oxalis control 4 Celebrating park stewards 8 Soil bacteria vs. invasive grasses 9 Sarah Minnick, Stewardship Coordinator of New threat to forests 10 Ring Mountain Preserve for Marin County WMAs: Who needs’em? 11 Parks, with a young volunteer. From the Director’s Desk Rats on islands By Executive Director Doug Johnson

slands invaded by rats are some of the clearest examples of invasive species’ impact Cal-IPC Ito biodiversity. They are also among the best examples of the potential benefits of 1442-A Walnut Street, #462 Berkeley, CA 94709 eradication. ph (510) 843-3902 fax (510) 217-3500 www.cal-ipc.org [email protected] Islands have historically provided critical breeding habitat for seabirds. And because Protecting California’s environment and economy of their isolation, they hold a preponderance of the world’s endangered biodiversity. As from invasive plants sailors circled the globe and visited remote islands, they inadvertently spread rats, which prey extensively on chicks and eggs and damage vegetation. In one example, Australia’s Lord Howe Island in the South Pacific, 30 wildlife species have disappeared since rats STAFF Doug Johnson, Executive Director arrived in 1918. Elizabeth Brusati, Senior Scientist New Zealand started working on this problem some 40 years ago. To date, over 400 Agustín Luna, Director of Finance, Operations & Administration islands have been cleared of rats. The typical technique is spreading poisoned bait from Bertha McKinley, Program Assistant the air. Groups like Island Conservation, headquartered in Santa Cruz, are taking the Dana Morawitz, Program Manager for GIS and Regional Conservation work global. Their projects span from protecting black oystercatchers in the Aleutian archipelago to the endangered Peruvian diving petrel on Choros Island off the Chilean coast. BOARD OF DIRECTORS Jutta Burger, President Most recently, the world’s largest ever rodent extermination was completed in 2015, Irvine Ranch Conservancy Gina Darin, Vice President removing rats from South Georgia Island in the south Atlantic. About 95% of the bird California Department of Water Resources life has been lost due to rat depredation, but with time, is expected to recover. In a sign Steve Schoenig, Treasurer Independent Consultant of things to come, the world’s most southerly songbird, the endemic South Georgia Tim Buonaccorsi, Secretary pipit, was found for the first time in living memory to be nesting on the main island. RECON Environmental, Inc. Jason Casanova, Past President Few invasive species control efforts are as clear-cut as removing rats from islands. For Council for Watershed Health invasive plant control efforts , we are tasked with sorting through the severity and types Jennifer Funk, Chapman University of impacts and the feasibility of control, and putting that all into the context of what’s Jason Giessow, Dendra, Inc. best for an evolving ecosystem. Still, the principle is the same, and it’s great to see the William Hoyer, US Navy Shawn Kelly, Southern California Wetlands Recovery Project potential for success. Drew Kerr, Invasive Spartina Project For a detailed telling, see William Stolzenburg’s 2011 Rat Island: Predators in Ed King, Placer Co. Ag. Commissioner’s Office Dan Knapp, Long Beach Conservation Corps Paradise and the World’s Greatest Wildlife Rescue. Visit Island Conservation’s website at John Knapp, The Nature Conservancy www.islandconservation.org. And see a video of results ten years after removal of rats Laura Pavliscak, Tejon Ranch Conservancy from Anacapa Island (pictured below) in the Channel Islands off the California coast at Heather Schneider, UC Santa Barbara www.youtube.com/watch?v=RDJgMt19GRI. Lynn Sweet, UC Riverside

STUDENT LIAISONS Marina LaForgia, UC Davis Amanda Swanson, UC Riverside

Affiliations for identification purposes only.

Cal-IPC News Summer 2016 - Vol. 24, No. 2 Editors: Doug Johnson & Elizabeth Brusati.

Published by the California Invasive Plant Council. Articles may be reprinted with permission. Previous issues are ar- chived at www.cal-ipc.org. Mention of commercial products does not imply endorsement by Cal-IPC. Submissions are welcome. We reserve the right to edit content. Channel Islands Restoration Channel Islands 2 Cal-IPC News Summer 2016 Cal-IPC Updates concentrations found that snails could survive in many conditions, but their re- Symposium program set. Join us near WildlandWildland productive output was low in both natural Yosemite for the 25th annual Cal-IPC waters and experimental low-calcium con- Symposium! More details page 6. WeedWeed NewsNews ditions. The results suggest that naturally- Submit photos and videos. Joining our occurring differences in water chemistry annual Photo Contest is our new “Weed may reduce the spread of mudsnails in California Invasive Species Action Workers of California” video project. We the park. Vazquez et al. 2016. Biological Week. The California Department of Fish want to hear from weed workers around Invasions. 18(6):1523-1531. California about the work you do and and Wildlife sponsored the second annual Homeowners willing to have invasive why it’s important to you. Send your CISAW June 4-12. To see what happened trees removed. A study in South Africa video of up to 60 seconds from the field and get ideas for next year, go to www. surveyed homeowners who had invasive (or the lab). See links for Photo Contest wildlife.ca.gov/Conservation/Invasives/ trees in their gardens. More homeown- and Video Submission on the Symposium Action-Week ers who had had exposure to media webpage. Open July 15-Sept. 15. Spring campaign a success. Thanks on invasive species knew their tree was Mapping arundo in the Central Valley. to everyone who contributed, we raised Cal-IPC and project partners includ- $46,000 in May to ing the Sonoma Ecology Center, River support an update Partners, and the California Dept. of to the Invasive Water Resources are mapping giant reed Plant Inventory (Arundo donax) across the San Joaquin and other Cal-IPC and Sacramento River watersheds using work. Thank you! aerial imagery. If you missed the Spring Campaign, Screening underway for emerging you can support weeds. Cal-IPC has begun screening Cal-IPC through 200 watch list species to determine our San Francisco their potential for becoming invasive in Marathon runners! California. www.crowdrise. Algerian sea lavender being treated. com/cal-ipc1. Cal-IPC is controlling invasive Limonium ramossisimum at ten salt marsh sites Other News around San Francisco Bay. This species is WHO clarifies: Shelley Phillip and Cal-IPC Vice-President Gina Darin handed a relatively new invader of upper marsh glyphosate not out Cal-IPC information at the Roseville Greener Garden Expo. habitats and has been spreading. a risk. A joint statement from Nature Reserve of Orange County. invasive. While most were not interested the United Nations and World Health Cal-IPC is delivering a five-year plan for in removing the tree themselves, most Organization (WHO)says that glyphosate invasive plant management and early (83%) said they would be willing to have (the active ingredient in RoundUp detection/rapid response (EDRR) for the the tree removed if it was taken down at herbicide) does not pose a cancer risk, 17,000-acre Coastal Subregion of the no charge by an appropriate agency. The clarifying the confusion over the WHO’s reserve. study was conducted in conjunction with recent designation of glyphosate as a new regulations that went into effect in Media contacts. High Country News carcinogen. For an explanation of the the South Africa in 2014. Shackleton, C.S. interviewed Cal-IPC about invasive plants difference between hazard potential and and R. T. Shackleton. 2016. Biological and climate adaptation, and Bay Nature actual risk, see www.wired.com/2016/05/ Invasions. 18(6):1599-1609. interviewed us about how new gene drive monsantos-roundup-herbicide-cause-cancer- technology might impact invasive species not-controversy-explained/ management. Stopping mudsnails in Redwood Keep current... Spreading the word. We presented a at National Park. New Zealand mud ...on the latest happenings in the the SERCAL restoration conference in snails are exotic mollusks present in weed world by keeping your Cal-IPC North Lake Tahoe, exhibited at the Bay many waterways of the western United membership up to date! Check your Area Open Space Council’s annual confer- States. In northern California’s Redwood membership status on the mailing ence in Richmond, and gave out “Don’t National Park they were first found in label of this newsletter. Renew online Plant a Pest!” brochures at the Roseville 2009. A study testing the response of or with the enclosed envelope. Thank Greener Garden Expo. snails to water conductivity and calcium you for supporting our work!

Cal-IPC News Summer 2016 3 Oxalis pes-caprae control trials

By Lew Stringer, Restoration Ecologist, Presidio Trust, [email protected]

ype Oxalis pes-caprae into the search application of treatments, Tbar of online mapping tools like baseline measurements were Calflora or iNaturalist and you will see taken in all 36 experimental an almost solid line of occurrence points plots. Percent canopy cover that run the length of the California coast for O. pes-caprae was estimated from Tijuana estuary at the Mexican over the 0.5 x 0.5 m area of border to Lanphere in Humboldt each plot and O. pes-caprae County. Imagine clicking on each of stem density was counted. those points to reveal a trove of hidden In February 2004, prior to photos, like a database subconscious, corm formation, all manual of managers wringing their hands and treatments were applied. In waving herbicide wands at this rapidly plots receiving the pick wandering weed. You would have found treatment, O. pes-caprae was a picture of me in 2004 standing over a removed by hand with the clip board scheming an end to its crowd- assistance of a hand pick. ing out of the little rare annuals that Plots receiving the hula-hoe we try to protect in the Presidio of San treatment were scraped with a Francisco. hula-hoe. All vegetation and Native to South Africa, oxalis has approximately 3 cm of top soil spread to all Mediterranean climate were pulled from the plots in regions of the world. It has been observed this treatment. The scraped forming dense carpets in plant communi- material was then removed ties such as grasslands and sand dunes from the sites. One set each Counting oxalis stem density. 2010. that harbor rare and endangered plants. of the pick plots and the In the late nineties and early aughts, our hula-hoe plots received a stewardship program spent many hours repeat treatment one month of staff and volunteer time ineffectively later. Plots receiving the tarp treatment Results and Discussion ® hand weeding oxalis from areas managed were covered with Lumite 300, black 2004 Manual Trial: Tarping was the for rare annuals. To improve our manage- UV stabilized polypropylene shade fabric only treatment that significantly con- ment we conducted two informal trials and pinned with metal fabric stakes. The trolled oxalis in the 2004 study. When in the Presidio to compare the efficacy of tarps were removed in October 2005. the Lumite tarps were removed in late mechanical, cultural and chemical con- Stem density and percent cover were October 2005 after 9 months staked to trols of oxalis. In the first trial in 2004, re-measured in January 2005. the ground, etiolated shoots could be we measured the impact of hand weeding 2009 Herbicide Trial: Twenty per- observed having recently germinated from versus tarping on oxalis cover and density. manent 1 m x 1 m plots were established corms. Most of these shoots were unable A follow up study was conducted in 2009 in November 2009. Plots were located to recover. (See figure next page.) to test the efficacy of herbicide on those in areas where O. pes-caprae percent cover parameters. The results of this study and subse- was relatively abundant. Four herbicide quent tinkering with tarping has refined Methods treatments with 5 replicates were our management of oxalis. We now use 6 randomly assigned to the 20 plots. On 2004 Manual Trial: At two sites in mm polyethylene black sheeting instead November 25, 2009, prior to the ap- ® the Presidio (sand and serpentine of Lumite as it is more effective at block- plication of treatments, stem density was grassland) 18 permanent 0.5 x 0.5 m ing photosynthetically active radiation. counted from a 0.5 m x 0.5 m quadrat plots were established in January 2004. Timing is also important. Tarping is now at the center of each 1 m2 plot to reduce Plots were located in areas where O. done in early to late-November or about edge effects. On December 17, 2009, pes-caprae percent cover was relatively 4 weeks after oxalis has emerged with prior to corm production, all herbicide high. Six treatments (including control) fall rains. At this life stage, most oxalis treatments were applied by Shelterbelt with 6 replicates were randomly assigned corms have germinated and have used up Builders to randomly assigned 1 m2 plots. to the 36 plots (see table). Prior to the the carbohydrate reserves stored in below Stem density was recounted in December 4 Cal-IPC News Summer 2016 ground corms. New corm formation has 2004 Manual Trial 2009 Herbicide Trial not yet begun at this stage. Most oxalis stems die within 6 to 8 weeks of tarping. Treatments Treatments Collateral damage to desirable vegetation 1) control (no treatment) A) 1% Garlon 4 Ultra + Competitor makes this treatment undesirable in certain areas, however we have observed 2) hula-hoe B) ½% Garlon4 Ultra + Competitor that several species of perennial forbs 3) repeat hula-hoe C) 1% RoundUp Pro Max + Trifol water and grasses are able to recover after being conditioner covered for the 8 week duration needed to 4) hand pick eliminate oxalis. 5) repeat hand pick D) 1% Rodeo Aquamaster + Syltac + Trifol water conditioner. 2009 Herbicide Trial: A significant 6) tarp change in O. pes-caprae stem den- Note: We did not include a “no treatment” sity was observed between pretreatment plot (November 25, 2009) and a year after treatment (December 1, 2010). It was its effectiveness, with plots that ranged a mistake not to include a control in It is often helpful to identify the least from 2-12 individuals after treatment. this trial; however, unquantified visual amount of herbicide necessary to provide The Rodeo and Roundup treatments observations of surrounding untreated effective kill. One important finding is both had plots with outliers in the high areas, while anecdotal, showed much that ½% Garlon4 Ultra with Competitor 20s. Having included a higher number of higher density than those in plots. A was significantly less effective than 1%. replicates in this study may have provided one-way analysis of variance revealed a While, there was no significant difference better clarity. between the effectiveness of 1% Garlon4 significant difference between the change While this experiment only tested Ultra with Competitor and 1% RoundUp in mean number of oxalis individuals the effects of each herbicide treatment Pro Max + Trifol water conditioner and pre- and post-treatment (p<0.05). Only on Oxalis, the known impacts of each 1% Rodeo Aquamaster + Syltac + Trifol Treatment B was significantly different herbicide on other plants and animals water conditioner, 1% Garlon4 Ultra with that Treatments A, C and D in 2010. provides greater flexibility when working Competitor had the smallest variance in to control Oxalis in different situations.

Effects of Manual and Herbicide Treaments on Oxalis pes-caprae Density 200 Pre treatment mean + standard deviation 180 Post treatment mean + standard deviation 160 2 140

120

100

individuals/ 0.25m individuals/ 80

60 Oxalis Oxalis 40

20

0 Hula Hoe Hula Hoe Hand Pick Hand Pick Tarp A B C D Repeat Repeat

Manual Treatments (2004,2005) Herbicide Treatments (2009,2010)

Cal-IPC News Summer 2016 5 Celebrating Park Stewardship

25th Anniversary Cal-IPC Symposium Nov. 2-5, 2016 Tenaya Lodge

Program Highlights Plenary sessions focus on invasive plant management as an integral part of park stewardship, with speakers including: Don Neubacher, Superintendent of Terri Hogan, National Invasive Plant Program Manager, Jay Goldsmith, Natural Resources Division Director, Pacific West Region, National Park Service Jay Chamberlin, Natural Resources Division Chief, California State Parks Mark Hylkema, Santa Cruz District Archaeologist & Tribal Liaison, California State Parks (on cultural resources) Katherine McEachern, Ecologist, US Geological Survey (on intersection with listed species) Mary Beth Hennessy, Deputy Director, Ecosystem Planning, US Forest Service (on intersection with wilderness designation) Jun Kinoshita, Fire Archeologist, National Park Service (on intersection with fire management activities) Dozens of other speakers and poster presenters will share findings on the latest in management techniques, research, and related land management topics. Continuing education credits will be appliced for from the California Dept. of Pesticide Regulation (12 units Other/2 units Laws & Regs )and Nevada Dept of Agriculture. Final program to be posted on Cal-IPC website in July!

6 Cal-IPC News Summer 2016 Registration Open! Early-bird rates through Sept. 15. Member: $295 / Non-Member: $350 / Student: $50 Register online at www.cal-ipc.org/symposia

Trainings (Nov. 2) Using Certified Weed-Free Forage and Mulch(11am-5pm, $60): Straw mulch used in restoration projects can introduce weed seeds. So can hay used for horses or livestock. Learn how to specify, source, and inspect hay or straw for use in wildlands.

Calflora’s Weed Manager Applications (1-5pm, $50): Map weeds on a smartphone and track treatment, using a custom interface designed for your organization? Calflora’s Weed Manager suite of tools is designed to do this and more.

Invasive Plant Management 101 (11am-5pm, $60): New to the field, or never got a full background on weed management? Get context for plant ID, weed biology, mapping, strategic prioritization, IPM control approaches, monitoring, permitting, and more. Field Trips (Nov. 5) and Nelder Grove of Giant Sequoias (8:30am-12:30pm, $25) Join Forest Service natural resource managers to visit the leading edge of yellow starthistle and medusahead moving up into the mountains, and walk in the giant Sequoias.

Merced River Canyon (8:30am-4:30pm, $50) See where a multi-agency campaign has knocked back dense infestations of yellow starthistle, Italian thistle and tree-of-heaven, including extraordinary treatments on steep rocky slopes using rope systems and high- Hunting for invasive blackberry in El powered truck-mounted spray rigs. Capitan Meadow. Photo by Garrett Dickman, Yosemite National Park. Yosemite Valley Tour – Weeds and Waterfalls (8:30am-4:30pm, $50) See Yosemite Valley through the lens of three invasive plant challenges: Himalayan blackberry, velvet grass, and annual grasses. and hear about research on native genotypes resilient to climate change. Plus... Discussion Groups  Poster and Exhibitor Session  Student Paper and Poster Contests Student Chapter Lunch  Awards Banquet Social Hour with Auction & Raffle Photo Contest and Video Montage! Submit your best photos (weed workers, scary infestations, specimen shots, humor, before and after) to our annual Photo Contest. Your contributions help Cal-IPC communicate about the work you do. And new this year, submit a short (up to 60 second) video for our “Weed Workers of California” montage. We want to hear about the work you do and why it’s important to you. Details at www.cal-ipc.org/symposia.

Both open July 15 to Sept. 15! Golden Gate National Parks Conservancy interns pull yellow starthistle. 2014 Cal- IPC Photo Contest. Photo by Suzanne Whelan, Marin Municipal Water District.

Cal-IPC News Summer 2016 7 is part of a multi-year partnership with Celebrating park stewards The Nature Conservancy that allows us to devote additional resources toward coordination, prioritization, and monitor- ur 2016 Symposium celebrates Halstead Meadow, crossed by the parks’ ing, all of which are important in protect- Opark stewardship in honor of the main highway. I feel fortunate to live and ing rare species and their habitat at Ring National Park Service’s Centennial. We work in such a large, biologically diverse, Mountain. asked a few Cal-IPC members about their and intact landscape. A personal goal is work in national, state, and local parks. to insure that yellow starthistle remains Jim Dempsey, Environmental excluded during my tenure here! Scientist, California State Parks Athena Demetry, Restoration Ecologist, Sequoia and Kings Sarah Minnick, Stewardship I am the natural resources manager for the Northern Buttes District, which Canyon National Parks Coordinator, Marin County Parks includes 15 park units in nine inland In 2001, I ushered Sequoia and Kings [Pictured on cover.] counties north of Sacramento. I grew up st Canyon National Parks into the 21 As the Ring Mountain Stewardship in Chico and 16 years ago returned to century by starting the parks’ first invasive Coordinator, I protect and restore serpen- live here, a town that is very lucky to have plant management program. Our 865,964 tine grasslands that are home to numerous the awesome Bidwell Park (a 3,670 acre acres are 97% wilderness, and we’re native and rare species, one of which (the wildland city park). I was talking with my fortunate that large extents of the parks Tiburon mariposa lily) grows nowhere else 89-year-old dad recently about Spanish in the world. It may be a small broom spreading down the watershed preserve in a sea of residential into the park, and we reminisced about development, but it holds great treasured family memories of spring wild importance for preserving the flower displays with rich scents of nectar, region’s sensitive biodiversity. now largely disappeared due to exotic With many edges, neighbors, grasses. Today, intrepid hikers venturing visitors, and trails, weeds come into the upper reaches of Bidwell Park in from all directions. I focus can still catch remnants of those historic my efforts on those that are able treasures, while they last. Sometimes we to infiltrate harsh serpentine need someone with clear memories over a soils, such as thistles in the generational time span to remind us what genus Centaurea and French has been lost, and what more may be lost. broom with its ability to alter It’s easy to lose track in our everyday rush. soil nutrients and eliminate What will the next generation bring? I grassland habitat. I am always work to stop weeds wherever I can, and keeping an early detection eye encourage everyone to get out there and out for new threats like barbed enjoy our wildlands today! Athena carrying plants for restoration. goatgrass. I en- gage the local commu- are relatively free of nonnative plants, so nity of residents, schools, we focus on prevention and early detec- and businesses in volunteer tion. Our control work targets invasive work as a way to share the perennial grasses (reed canarygrass and importance of this preserve velvet grass) in meadows, a highly-valued and encourage participation ecosystem. Although these species are in its stewardship. It takes challenging to control—reed canarygrass the coordinated efforts of builds a dense thatch layer that excludes volunteers, contractors, native plant recolonization—they are and staff work groups of limited distribution in the parks and to keep the worst weeds eradication may be possible. Wearing my under control. Thanks to “disturbed lands restoration” hat, I’ve also such efforts, we eradicated planned and implemented the removal yellow starthistle from the of nearly 300 buildings plus roads and preserve in 2007, and we parking lots from the parks’ premier giant continue to control pampas sequoia grove, Giant Forest, and the grass. Marin County Parks restoration of a deeply eroded wetland, Jim with a group of Boy Scouts. 8 Cal-IPC News Summer 2016 Native soil bacteria as biocontrol

By Travis Bean, UC Riverside and Elise Gornish, UC Davis, [email protected]

iological control of invasive plants Bcan have many advantages over more conventional management methods, namely the potential for regional scale control of target species over the long term if the control agent can be effectively established. It also avoids the often-un- popular use of herbicides and the habitat disturbances involved with mechanical and physical control. However, because biological control often relies on moving the control agent from one region to an- other, it can require extensive research to ensure there is neglible risk of unwanted impacts on non-target native or desirable organisms. In the best case, the control agent would be native to the region, just not present in sufficient numbers to cause the desired effect on the target invader. Cheatgrass invades pinyon/juniper/sagebrush country in the intermountain west, This is an actual scenario that changing the vegetation community by altering the wildfire regime.BLM photo from may yield a novel tool for managing the Salt Lake Tribune. invasive Eurasian winter annual grasses in the western United States, thanks to effects on biodiversity and productivity Other positive results that would USDA-ARS researchers in Oregon and of range and croplands. To investigate increase its utility in an Integrated Pest Washington. They have recently publi- this possibility, researchers have screened Management (IPM) program for Eurasian cized the results of a long-term field trial over 20,000 potential bacterial candidates winter annual grasses include tests of over investigating the utility of native soil bac- through greenhouse experiments and field 200 non-target plants demonstrating that teria for selective control of the cheatgrass trials over the last 20 years located around the bacteria do not affect crop or native (Bromus tectorum, a.k.a. downy brome), the inland Pacific Northwest for selective species, meaning that P. fluorescens can jointed goatgrass (Aegilops cylindrica), control of cheatgrass, medusahead, and provide selective control of the target and medusahead (Taeniatherum caput- jointed goatgrass. invaders. In the presence of P. fluorescens, medusae), while not adversely impacting crops and natives are able to competi- native plant species. Recently, they made a breakthrough with Pseudomonas fluorescens strain tively dominate the suppressed weeds and Research into this promising man- ACK55. By using ACK55 similarly to a increase in cover. Research has also found agement tool started in the 1980s in pre-emergent herbicide, researchers found that P. fluorescens does not inhibit fish, eastern Washington when Pseudomonas (a that at a rate of one pint of active culture birds, bees, and other insects. Moreover, common genus of soil bacteria native to (1 x 108 colony forming units mL-1) per since the strain has no known anti- much of the western U.S. and elsewhere) acre, sprayed in the fall prior to emergence fungal or anti-bacterial activity, it is not was found on the roots of stunted winter of the target invasive plant species, P. expected to disturb the native microbial wheat and associated with a reduction fluorescens ACK55 is extremely effective at communities. in tiller number in affected plants. controlling cheatgrass, jointed goatgrass, As is the case with pre-emergent herbi- Recognizing that many of the Eurasian and medusahead by inhibiting root cell cides, which this biological control agent winter annual grasses which are ecosystem elongation and tiller initiation. In fact, a most resembles in terms of application transformers in the western U.S. are close single application appears to be adequate protocols, researchers have stressed that relatives of wheat, researchers wondered for almost eliminating these annual weeds several other factors, such as soil proper- if the bacteria might also negatively affect from the seed bank in the long-term (4-5 ties, temperatures, and precipitation, can these invaders and offer a potential man- years). This is about the normal lifespan agement tool to mitigate their negative of P. fluorescens in the soil. ...continued page 14 Cal-IPC News Summer 2016 9 New pest-disease complex threatens California forests

By Shannon Lynch, Akif Eskalen, Gregory S. Gilbert, UC Riverside and UC Santa Cruz. [email protected]

ogether with the avocado industry, A Complex Management Problem land managers of native forest T The dieback is caused by the com- communities in southern California face bined effects of two ambrosia beetles (the the imminent threat of a new emergent polyphagous and Kuroshio shot hole pest-disease complex: Fusarium dieback borers; PSHB, KSHB, both Euwallacea – Shot Hole Borers (FD-SHB). Our spp.) and the specific fungal pathogens work points to a path forward to make each beetle carries (Fusarium euwallaceae informed decisions on best approaches to and Fusarium sp.) management. In 2003, a single PSHB beetle was caught in a California Department of Food and Agriculture trap in Long Beach. The beetle went unnoticed until 2012 Ambrosia beetles, also known as shot- when it was found damaging backyard hole borers, interact with fungus to cause avocado and urban forest trees in the dieback of trees. Photo by Shannon Lynch Los Angeles basin. A rapid monitoring response uncovered the broad host range riparian, oak woodland, and mixed of the pest-disease complex, but its ability evergreen communities highly susceptible to establish in native vegetation was only to invasion and mortality by FD-SHB gradually recognized. (Eskalen et al., 2013). By October 2015, FD-SHB infested over 280,000 native Since 2012, these pests from Southeast trees in the Tijuana River Valley in San Asia have killed or caused dieback of Diego County, including arroyo willow 41 tree species on which the beetles can (Salix lasiolepis), Goodding’s black willow reproduce, including 17 California natives (S. gooddingii), and mule fat (Baccharis (see sidebar, page 12). Another 262 spe- salicifolia) (see figure, pg. 13, Boland cies in 64 families are attacked but do not 2016). We continue to confirm FD-SHB support beetle reproduction. However, attacking native vegetation in many new The beetle gallery in an infected tree. they provide a substrate from which the areas throughout San Diego, Los Angeles, beetle may find reproductive hosts. Orange, and Riverside Counties (Eskalen Controlling emergent pests in the This broad host range makes native and Lynch pers. obs.). critical early stages of invasions is gener- ally difficult because costly management These particular plant communities decisions must be made with insufficient are critical breeding habitat for endan- data. Which areas are most vulnerable to gered species such as the least bell’s vireo an infestation? How do invaders spread (Vireo bellii pusillus), southwestern wil- across a landscape? What management low flycatcher Epidomax( traillii extimus) options are most effective? and arroyo toad (Anaxyrus californicus). As FD-SHB kills willows, cottonwood, Decision-making is further en- and mule fat, it can make riparian tangled when invaders spread across habitats more susceptible to invasion by multiple land-use jurisdictions. Such giant reed (Arundo donax) and saltcedar uncertainty can cause delays and inef- (Tamarix spp). ficient and ineffective use of resources. Our research team has developed an At these early stages of the epidemic, approach to reducing this uncertainty to preventative and containment measures confront FD-SHB with both short- and can fortunately still be effective, provid- long-term control solutions. ing adequate, rapid assessment of key landscape factors. After the beetles leave, the Fusarium fungal pathogens continue to colonize the wood. ...continued page 12 10 Cal-IPC News Summer 2016 WMAs, who needs ‘em? The low desert, for one

By Lynn C. Sweet, UC Riverside, [email protected]

ecently, representatives from state, as in the case of Sahara mustard (Brassica of Cal-IPC’s existing resources? What Rfederal, tribal and county agencies as tournefortii), which was brought in as a are the prospects for restoring funding to well as local organizations came together contaminant from northern Africa with WMA programs? in a small room in Palm Desert. The date palm operations. Though the ability of the group to goal: to resurrect the Low Desert Weed In the low desert, focus has been initiate projects will be limited by the Management Area (LDWMA), which directed in recent years to areas where current lack of seed grants, the LDWMA covers parts of Riverside and San Diego invasive plants threaten federally endan- believes it can nonetheless provide useful counties containing the Colorado and gered species, such as the Coachella Valley coordination in many areas, including: Mojave Deserts. The process was jump- fringe-toed lizard, an endemic species invasive species mapping and monitor- started by members of the commu- ing; control project coordination; nity who felt a vacuum in the wake volunteer mobilization; and of a Natural Resource Conservation information-sharing on environ- Service-funded coordination program mental review issues. Led by the staff that had brought together partners from the Coachella Valley Resource and stakeholders for several years to Conservation District and an ad-hoc work on invasive plant problems, but committee, many of the members of had flagged after the funding cuts the LDWMA are also involved with to the California Dept. of Food and monitoring and management through Agriculture’s WMA program. the Coachella Valley Multiple Species For years, WMAs in California Habitat Conservation Program, benefited from funding for priority which provides a strong foundation on-the-ground weed control projects and existing network of diverse as well as the much-needed coordina- skillsets and experience among the tion process itself (meetings, project stakeholders. planning, platforms for sharing data). Also, knowing that Cal-IPC has After the cuts, only some WMAs stepped into a role as regional facilita- have continued to meet, buoyed by An Urban Conservation Corps crew works on tor across the state, helping WMAs in-kind donations of time, tools and tamarisk in Palm Canyon. Photo by Jennifer Prado, set priorities and pursue funding, dedicated intentions to coordinate Friends of the Desert Mountains gives us a sense that there is some invasive plant management on the outside support for this effort. A few ground. that UC Riverside researchers found to other regions have successfully secured Resurrecting an organization is not be negatively impacted by Sahara mus- grants for weed management projects easy, and some soul-searching has been tard. In addition to research on how to from state restoration programs funded by part of the process for the LDWMA. utilize phenology and chemical controls, bond measures, and as we move forward The group is diverse. Desert systems in efforts to control Sahara mustard have we may investigate the potential for a California (and elsewhere) harbor many been primarily the domain of organiza- similar effort in our region. rare and endemic species, as well as suites tions such as the Friends of the Desert Mountains, who mobilize volunteer forces Finally, we hold out hope that at of species in ecosystems found nowhere the state level, funding will be restored else. While not as ecologically produc- to pull weeds, with some notable successes in priority areas. because a small ongoing budget for local tive as coastal or northern systems, the weed management coordination is an ex- Colorado Desert has its share of invasive The question for the LDWMA and cellent investment in protecting the state’s species, plants that can make quick work other WMAs is how to coordinate efforts environment. It would certainly provide of open areas during the short winter without the push of funding. Members the basic funding for this essential early rainy season or within the riparian and of the LDWMA are discussing these detection network and pay dividends for seasonally-wet corridors that snake among other questions to target the best sensitive species, water supply, agriculture, through the canyons and valleys. Many directions, aims and goals of a WMA in fire safety and a host of other important invaders are native to other arid regions, the sans-funding era. Without having issues. The LDWMA currently meets from which they were imported for wind- the “carrot” of funding for on-the-ground quarterly in Palm Desert, CA. To join, breaks (such as Tamarix species) or were efforts, what are the concrete benefits of a contact [email protected]. brought in accidently with agriculture, WMA? How can we best take advantage Cal-IPC News Summer 2016 11 Such early detection surveys and ...Pest-disease from page 12 site-specific risk assessments help decision- Native trees and shrubs affected: makers focus resources in the face of Current practices in avocado groves Box elder (Acer negundo) insufficient data, and have reduced costs and urban forests rely on control measures of management of invasive ambrosia California sycamore such as systemic pesticides that are not beetles by 39% compared with no surveil- (Platanus racemosa) generally appropriate for use in native lance (Epanchin-Niell et al. 2014). This habitats. Similarly, chipping infested Red willow (Salix laevigata) adaptive model, continuously improved wood to a size smaller than 1 inch, fol- Black willow (Salix nigra) with new survey data and field testing, lowed by solarization, kills the beetles, but will help prioritize management efforts to Arroyo willow (Salix lasiopeis) it is not possible to cull trees that provide specific sites and avoid unfruitful efforts nesting habitat for endangered bird Cottonwood (Populus fremontii) in low priority sites. species. Black cottonwood An integrated pest management (IPM) Controls in Development (Populus trichocarpa) program for native vegetation includes Two approaches are being studied to Engelmann oak (1) developing tools to quickly detect new effectively control FD-SHD. The first (Quercus engelmannii) infestations and identify the beetles and approach uses pesticides. Several systemic Valley oak ( ) fungi; (2) identifying which habitats are pesticides identified in preliminary field Quercus lobata most vulnerable to FD-SHB and are most experiments show promise for controlling Palo verde (Parkinsonia aculeata) important in its spread; and (3) evaluat- the beetles and fungi on individual trees Mule fat (Baccharis salicifolia) ing preventive and curative biological, if applied prior to infestation (Eskalen mechanical, and chemical control options et al. unpublished data). Our landscape- Big leaf maple (Acer macrophyllum) appropriate for different habitat types. based risk assessment will help reduce the Coast live oak (Quercus agrifolia) environmental impacts of such pesticides Early detection and rapid identifica- White Alder (Alnus rhombifolia) tion are critical. With two beetle species by targeting their use as they continue to Blue palo verde (Parkinsonia florida) and at least two fungal pathogens involved be tested and developed. in this pest-disease complex (Lynch et The second approach uses endophytes Mesquite (Prosopis velutina) al. 2016), molecular tools to quickly and for biological control. Endophytic fungi Goodding’s black willow accurately identify the beetles and fungi and bacteria live inside plant tissues, and (Salix gooddingii) are being developed to tailor control are analogous to the gut microorganisms measures to the appropriate pest-disease that play a role in our own immune complex (Stouthamer unpublished). systems. We have already isolated sev- Summary Rapid identification tools are also essential eral endophytes from local avocado and Appropriate management protocols for for accurate mapping of the distribution sycamore trees that escaped disease, and FD-SHB are contingent on a number of of FD-SHB. But impacts and site-specific found they reduced the growth of the different landscape factors. Understanding risk cannot be determined based only on Fusarium pathogens. Our preliminary these factors is time-sensitive and will re- where the beetles have already arrived. results additionally show that Fusarium sult in long-term cost savings. Landscape spp. cannot colonize young avocado and Risk Assessment of Habitats assessments are urgently needed to sycamore plants inoculated with beneficial provide managers with the information Effective management of an emergent endophytes. they need to prioritize use of limited pest-diseases complex requires predicting We are currently working with land funds. Individual stakeholder agencies can where it will spread and cause damage. We managers to collect endophytes from play a critical role by helping us docu- have begun a systematic survey through- additional surveyed native trees and ment current impacts to better inform out regional urban-wildland forests and test their biocontrol potential. We are an integrated landscape risk model of the agricultural lands, and are measuring conducting experimental trials to test spread of FD-SHB. For updates and more vegetation and landscape characteristics, if these protective endophytes can be information, visit www.eskalenlab.ucr.edu microclimate, and resident beneficial inoculated prophylactically into seedlings and www.pshb.org. microorganisms across sites. and saplings of native plants to facilitate Literature Cited By combining these survey data restoration of habitats and improve with what we know about host range landscaping even where FD-SHB has Boland J.M. 2016. The devastating impact of into an adaptive risk model, we can an invasive ambrosia beetle on the riparian habi- become established. tats of the Tijuana River Valley, California. PeerJ interpolate likely areas of spread into an Our risk model will be used to evalu- Preprints 4:e1964v1https://doi.org/10.7287/ interactive map tool to aid managers with ate locations where resident endophytes peerj.preprints.1964v1 decision-making. may reduce vulnerability and where Epanchin-Niell, R.S., Brockerhoff, E.G., endophyte treatments may be most useful. Kean, J.M., & Turner, J.A. 2014. Designing 12 Cal-IPC News Summer 2016 Severe dieback in native vegetation due to FD-SHB over the course of one year in the Tijuana River Valley.

cost-efficient surveillance for early detection and dieback and its ambrosia beetle (Coleoptera: nov.- two newly discovered mycangial as- control of multiple biological invaders. Ecological Scolytinae) vector in southern California. Plant sociates of the polyphagous shot hole borer Applications 25(6): 1258-1274. Disease 97(7):938-951. (Euwallacea sp.) in California. Mycologia. DOI: Eskalen A., Stouthamer R., Lynch S.C., Lynch S.C. et al. 2016. Identification, 10.3852/15-063. Rugman-Jones P.F., Twizeyimana M., Gonzalez pathogenicity and abundance of Paracremonium A., Thibault T. 2013. Host range of Fusarium pembeum sp. nov. and Graphium euwallaceae sp.

Cal-IPC News Summer 2016 13 ...Soil bacteria from page 9 enough of the bacteria to supply it to suggest that post-emergent herbicides be farmers, ranchers and conservationists applied to reduce the standing crop of mediate treatment effectiveness, spe- interested in using it to control invasive invaders, while also applying the bacteria cifically noting that the bacteria may not winter annual grasses in the western U.S.? to attack germinating seedlings and perform as well under hot and arid condi- Because it’s likely to be cost-prohibitive to provide seed bank control over the longer tions experienced in summer months. As apply the bacteria to all of the millions of term. Seeding or planting natives or desir- with all invasive plant management and acres currently infested by these problem able forage species can help reestablish a restoration methods, timing is critical; species, the researchers suggest that a diverse and resilient plant community that along with cooler temperatures, precipita- more targeted approach be considered. can resist or prevent recolonization by tion is required within two weeks of One approach would be direct applica- invasive grasses. application for the bacteria to effectively tion of the bacteria to leading edges of colonize the soil. This means that success- For more information: existing infestations to quarantine existing Ibekwe, A.M. et al. 2010. An assessment of ful application relies heavily on seasonal populations and prevent spread into new environmental conditions for control of downy precipitation and a lack of unseasonably areas. Other priority targets are firebreaks brome by Pseudomonas fluorescens D7. www.ars. warm fall weather, which may be more to control wildfire spread and recently usda.gov/SP2UserFiles/Place/20360500/pdf_pubs/ limiting in future years under some burned areas where the existing popula- P2098.pdf climate change scenarios. tion of invasive grasses is restricted to the Kennedy, A. et al. Microbial control of cheatgrass, jointed goatgrass and medusahead P. fluorescens ACK55 is currently seed bank, allowing the bacteria to have (presentation). www.fwaa.org/accounts/fwaa/ undergoing the EPA registration process, the largest impact. data_documents/60/files/10b-dl-2011-12- which can take about 17 months. If Additionally, site-specific factors may 13_130p_kennedy,ann.pdf Kennedy, A. et al. Cheatgrass suppressive accepted by EPA, the inoculate could be limit effectiveness of the bacteria for bacteria research (factsheet). http://sfc.smallfarm- available for widespread use. In California, invasive grass control. As we often hear central.com/dynamic_content/uploadfiles/152/ pathogens intended for controlling weeds restoration ecologists and practitioners biocontrols%202.pdf require authorization from the California emphasize, control tools are most effective Dickie, G. 2015. Researchers find an answer Department of Pesticide Regulation, when used as part of an IPM program, to invasive cheatgrass. High Country News, www. and other states may have similar rather than as a stand-alone treatment. In hcn.org/articles/researchers-find-formidable-foe-for- requirements. invasive-cheatgrass fact, as the researchers themselves suggest, Solomon, C. 2015. Researcher finds way Other than state-specific restrictions the bacteria is unlikely to be successful if to fight cheatgrass, a western scourgeNew York on using pathogens for invasive plant simply applied to invasive grass monocul- Times, www.nytimes.com/2015/10/06/science/ control, there are also the hurdles of tures, as the grasses will simply regenerate researcher-finds-way-to-fight-cheatgrass-a-western- scourge.html propagation: what is the cost of growing given sufficient time. Instead, researchers

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The WILDLAND WEED CALENDAR UC Davis Weed Day Natural Areas Conference Do No Harm: July 7, UC Davis October 21-22, Davis Non-Native Species in Restoration wric.ucdavis.edu www.naturalareas.org November 15, UC Davis ucanr.edu/sites/UC_ANR_Do_No_Harm North American Congress for Cal-IPC 2016 Symposium Conservation Biology November 2-5, Tenaya Lodge, Yosemite California Association of RCDs July 17-20, Madison, WI www.cal-ipc.org November 16-19, Ontario www.conbio.org/groups/sections/north-america www.carcd.org Bay Delta Science Conference Central California Invasive Weed November 14-17, Sacramento North American Invasive Species Forum Symposium scienceconf2016.deltacouncil.ca.gov May 9-11, 2017, Savannah, GA October 6, Marina www.invasivespecies2017.org www.cciws.org

“ Researchers have been desperately looking for a way to overthrow cheatgrass’s reign for decades, and have tried some wacky experiments in the process — from fungal pathogens like the macabre Black Fingers of Death to changing soil texture to introducing super absorbent polymers into the ground to soak up water. Now, after nearly 30 years of trials and research, Ann Kennedy has found the innocuous cure — native soil bacteria.” ~ From “Researchers find an answer to invasive cheatgrass”. Gloria Dickie,High Country News, Oct. 16, 2015, www.hcn.org/articles/researchers-find-formidable-foe-for-invasive-cheatgrass