Abstract:

Watsonville Slough System Local Native Seed Production

Presented by Mary K. Paul, Restoration Specialist at Watsonville Wetlands Watch 

Watsonville Wetlands Watch has been helping to restore the wetlands and adjoining uplands of the Watsonville slough system for the past twenty years.  Currently the Wetlands Watch is managing close to 1000 acres of freshwater wetlands and uplands.   As part of the restoration program, Watsonville Wetlands Watch has established a 1.25 acre native grassland and wildflower farm for native seed production to be used on various restoration sites in the slough system.  Mary will talk about the methods and process involved in the establishment, maintenance, harvesting, and processing of the seed from the seed farm as well as the process and methodology used in the seeding of these restoration project sites.

Abstract:

Scotch broom control in the context of forest regeneration:  “It’s not just the weeds."

Parker, I.M.^1*, K.A. Haubensak², S. Grove¹, J.R. Foster³, and N.F. Benson³.

¹University of California-Santa Cruz, Department of Ecology and Evolutionary Biology, Santa Cruz, CA; ²Northern Arizona University, Merriam-Powell Center for Environmental Research, Flagstaff, AZ;  ³Joint Base Lewis-McChord, Department of Forestry, Yelm, WA.

*imparker@ucsc.edu

Invasion of Scotch broom (Cytisus scoparius) is associated with failed reforestation efforts in the Pacific Northwest.  The goal of restoring mature Douglas-fir forest strongly constrains the options for broom control relative to restoring grasslands, yet it also suggests opportunities for long-term success.  We present the results of a large-scale, replicated experiment testing the efficacy of broom control methods in the context of reforestation at Joint Base Lewis-McChord, Washington.

Following initial clearing of Scotch broom at five sites, we implemented 12 treatments to (1) compare different approaches to control, while (2) providing insights into the growth dynamics of broom across these sites.  Soil scarification was used to manipulate the seed bank in an attempt to provide sufficiently long-term mechanical control for newly planted trees to establish.  Herbicide control was compared to mechanical control. Herbicide was also compared across three times of year (different seasons) and across years (=different size of broom plants).  We measured resprout rates of the initial cleared individuals, germination of broom from the seedbank, and broom cover for five years following initial clearing.

Both germination and resprouting varied substantially across sites. Resprouting of Scotch broom stumps did not depend significantly on stump diameter or height.  Soil scarification with large equipment, even when done repeatedly, was not an effective control method.  Herbicide was a highly effective approach to Scotch broom control in this system, and kill rate was high for 1-yr, 2-yr, and 3-yr plants. Percent cover of broom did not differ significantly between early spring, late spring, and fall applications after two years of growth, but after three years of growth the late spring application seems to be showing the best long-term control.

We observed very high mortality of Douglas fir seedlings in our experiment over repeated planting cycles. Our previous work suggests that broom may alter soils so as to inhibit growth in previously broom-invaded sites.  Thus broom leaves an ecological “legacy effect” on wildlands and managed forests.

KEYNOTE ABSTRACT:

Reclaiming Common Ground:  Emerging Conservation Success in the Watsonville Slough System.

Jonathan Pilch. Restoration Director, Watsonville Wetlands Watch

The Watsonville Slough System, on the largest freshwater slough systems on California’s coast is experiencing rapid growth in conservation, ecological restoration, and a rise in education and awareness of this important resource.  Dynamic partnerships and over 20 years of focused effort of planning, open space acquisition, community action and environmental restoration is beginning to yield significant results in the return of native habitats, biodiversity, and special status plant and animal species.  Championing this work, is Watsonville Wetlands Watch, who in close collaboration with others has been working since the early 1990’s toward a vision of a high functioning slough ecosystem.  This work has included efforts to restore and enhance rare native coastal prairie plant communities and other native habitats surrounding the freshwater sloughs, a citizen science monitoring program for native and invasive plants and wildlife, environmental education for Watsonville area youth, and close work with a variety of public agencies and the agricultural community to restore native habitats and find common ground in meeting multiple objectives.  Jonathan Pilch, Watsonville Wetlands Watch’s Director of Restoration, will share the current state of this important work. 

ABSTRACT:

NOT YOUR AVERAGE 10,000 ACRE CLEARCUT:  

The Agony and the Ecstasy of Two Decades of Invasive Species Control in the Forest of Nisene Marks

Ken Moore, Founder, Wildlands Restoration Team

The Forest of Nisene Marks contains some of the most formidable terrain in Santa Cruz County.  USGS surveyors initially deemed it too difficult to even survey. They simply drew a line on their map around the two watersheds which comprise what is now the park, and did not venture inside. In 1883, this land became the site of one of the largest clearcut logging operations ever undertaken in this part of the state, producing some 140 million board feet of lumber in 40 years of intense activity.  If you are thinking all this may have introduced some weeds, you are correct. 

Invasive species control in such a place was not a task to be approached lightly. It required months of  precipitous bushwhacking just to see what's on your 10,000 acre plate. Then the real work starts, much of which must be done in rope.  Hours of rugged cross country hiking time are often necessary just to reach a site.  Any injury here can quickly become life-threatening.  Radio communication does not reach into these deep canyons, and rescue help is unlikely.

In 1991, with no funding, the fledgeling all-volunteer Wildlands Restoration Team picked up the gauntlet, and began clearing a host of established invasive species: French broom, Jubata grass, Cape ivy, Eucalyptus, Acacia, English ivy, Vinca, Holly, and Eupatorium. 

It meant working long, exhausting days, in every kind of weather.  New volunteers often never came back, but those that stuck with it developed a deep pride in their accomplishments, and an all-empowering "can-do" approach to large-scale weed control in conditions they initially thought would be impossible. A good number of them are now professional weed warriors.

Many new control methods, tools, and strategies were developed and implemented for the uniquely challenging conditions encountered here. Over 20 years and 10,000 hours later, this is the story of what worked, what didn't, --and why.

ABSTRACT:

TARPING, HERBICIDE, SOIL REMOVAL, AND MULCHING AS METHODS TO REDUCE EXOTIC COVER AND RESTORE NATIVE COASTAL PRAIRIE GRASSES

Karen Holl, Jamie Russell, E. Tyler Mann, Elizabeth Howard, Tara de Silva, and Will Spangler

We tested different strategies to control exotic forbs and grasses, and reduce competition with planted native grasses as part of coastal prairie restoration efforts at the University of California, Santa Cruz Younger Lagoon Natural Reserve.  During summer/fall 2010, we set up an experiment comparing several exotic control treatments including one-time (1×) tarping with black plastic, two-time (2×) tarping, topsoil removal (scraping), herbicide, and no treatment crossed with applying mulch and not mulching.  Three native grass species (Nassella pulchra, Elymus glaucus, and Hordeum brachyantherum) were outplanted in January 2011.  We monitored native and exotic vegetation in spring and summer 2011, as well as spring 2012.  Overall, 1× tarping, 2× tarping and herbicide were similarly effective in reducing exotic grass cover and favoring native perennial grass growth.  Mulching increased soil moisture and was particularly effective in controlling exotic cover in control and scraped plots where exotic cover was high; moreover, the mulch had decomposed substantially by spring 2012.  Scraping was ineffective in reducing exotic cover and resulted in low native grass cover, as the slight change in microtopography caused by soil removal resulted in extensive flooding of scraped plots.  Our results suggest that tarping once in the fall following the first rains and mulching are effective methods for reducing exotic forbs and grasses during the early stages of coastal prairie restoration.  We are continuing to collect data to evaluate long-term efficacy of the treatments, as well as to test different combinations of herbicide and tarping to control weeds in the initial stage of coastal prairie restoration efforts.

ABSTRACT:

The Butterfly Effect: the challenges of using pesticides within habitats of federal and/or state-listed wildlife species.

Joel Trumbo Staff Environmental Scientist CA Dept of Fish & Game Wildlife Branch, Lands Program

The U.S. EPA’s requires pesticide manufacturers to submit numerous studies for review as part of its pesticide approval process. Studies related to non-target impacts to invertebrate species, however, are limited. With regards to the approval of herbicides, only one study, a honeybee contact toxicity study, is required in the basic suite of studies. This lack of data makes it difficult to assess the risk posed to non-target invertebrate species when herbicides are used in invasive management programs. Recent research indicates the potential for some commonly used invasive weed herbicides to pose a direct toxicological risk to invertebrates.   

The lack of invertebrate toxicity data begs the question, are honeybees a suitable surrogate for assessing herbicide risks to other invertebrates? If not, are there other species that would be appropriate surrogates? For example could readily-available fish toxicity data provide a reliable assessment of invertebrate risk? Additionally, even if laboratory studies suggest direct toxicological risk, do these studies accurately characterize non-target organism exposure during actual herbicide applications in the field? Further how can decisions about herbicide selection, application methods and timing be used to provide further protection for non-target invertebrates even if data gaps exist.

This presentation will explore practical ways for land managers to interpret herbicide toxicity studies.

Joel can be reached at the following: (916) 445-8544 jtrumbo@dfg.ca.gov