Spring Planting and Weeding Plans at NCOS

Wed, 03/06/2019 - 09:14 -- Ryan Clark

Spring is on our doorstep, and with the North Campus Open Space restoration project well into its second year, we're taking stock of the planting progress and plans for the coming months. We now have more than 61 acres planted. This includes all of the saltmarsh (about 19 acres) and grassland (17.5 acres), and most of the Transitional Saltmarsh and Peripheral Uplands. There are about 17 acres remaining to plant. This is primarily the 12 acres of Coastal Sage Scrub and Chaparral on the north-facing slopes of the Mesa. Restoration work in the spring will focus on planting this area and on controlling this year’s rain-stimulated germination of weeds from the soil seed bank across the whole site.

If you've been out walking on the trail lately, you may have noticed small flags and plugs of salt grass (Distichlis spicata) in the bare, muddy zone right next to the trail edge. CCBER staff and volunteers have been planting these areas over the past three months, working on a vision of a trail edge that is stabilized with this low-growing, rhizomotous salt grass. This will help reduce weed colonization along the trail edge, provide a safe place for people to stand aside for vehicles or bikes to pass, and stabilize the trail against erosion. To help this vision become reality, we ask users to kindly stay on the trail substrate while the salt grass cover gets established.

   Left: Recent plantings of salt grass along the trail edge. Right: established cover of salt grass along the trail edge.

One of the primary goals of the NCOS project is to re-establish populations of locally sourced genotypes of native plants. To achieve this goal successfully, it is vital to control invasive plants that can outcompete these newly planted seedlings. By making a concerted and focused effort on controlling invasive plants on the newly disturbed and exposed soil in these first few years of the project, we can create a window of opportunity for the native plants to become established and essentially shade out and limit weed germination and growth.

With the current combination of the distured soils and the grant resources to help achieve this goal, we are using all of the tools in the tool box to control invasive species now so that, in the long run, we can have a more stable, native-dominated landscape that will not require a high level of maintenance. Once an area has been planted with natives, weed-whacking and solarizing with black plastic are less viable tools. We then use a combination of hand-weeding, salt spreading to control salt intolerant non-natives in zones where salt-tolerant natives are planted, and herbicide. We are very judicious in balancing our use of these tools as we consider both the budget and the environment. The benefit of herbicides are that a larger area can be covered efficiently, and that the soil is not disturbed during the application. When weeds are pulled the soils are disturbed, which in turn leads to germination of more weeds. CCBER has a California State certified Qualified Applicator who knows all of the requirements for safe handling and use of herbicides, and conducts regular training of staff. By focusing on controlling the weeds now, we can greatly reduce the need for herbicide as a tool into the future. We understand the concerns that some NCOS users have regarding this and we are doing our best to limit our use to the minimum necessary to achieve the long-term vision of a healthy, diverse, native dominated ecosystem that supports the full complement of native organisms. Once the natives have become established they will stabilize the soil, shade out weeds and be able to fill the seed bank with native seeds.

In some areas of NCOS there is a high diversity of weed species germinating, particularly along the trail edges, while in other areas, where subsoils with a smaller seed bank were brought to the surface, such as on the mesa, the seed bank is much reduced. We are conducting a study to document the density and diversity of natives and, most importantly, non-native species that sprout in the soil seed bank from several key areas of NCOS and, for comparison, from the less-managed and more weed-dominated Del Sol and Camino Corto open space in Isla Vista. Recently collected data indicate that the soil seed bank at Del Sol and Camino Corto holds 23 non-native species and 759 non-native plants germinating per meter square, while the seed bank of the newly planted grassland on the NCOS Mesa has just 11 non-native species and only 59 non-native germinants per square meter. These lower numbers on NCOS are encouraging for our effort to control the invasive species and create the vital window of opportunity for unique native plants to get established.

    A monkey flower shrub in bloom at NCOS - one of the species that will soon be planted on the slopes of the Mesa.

Looking toward the future, we have at least 17 acres left to plant as well as additional acres of perennial grassland to enhance with wildflowers in the coming years. We will be focusing on the coastal sage scrub, grassland and chaparral communities on the Mesa slopes as well as completing the trail edge and filling in areas of the saltmarsh and riparian habitats over the next year. As you look toward the slopes of the Mesa, envision patches of orange-flowering monkey flower, red and grey California fuschia, and bright yellow golden yarrow standing out from grey-green patches of coastal sage scrub and taller oak chaparral plantings of coast live oaks, lemonadeberry, coffeeberry, and elderberry. The layout of the planting palette was done with consideration for the views from the future Mesa Trail, soil moisture and texture, and the needs of the insects and wildlife that will use the site. We look forward to your help with planting any day of the week and especially on community planting days on the second Saturday of the month. March 9th is our next community volunteer day - contact us at ncos@ccber.ucsb.edu to RSVP or inquire about volunteering any other day!

   Coast live oaks recently planted on the northern slopes of the NCOS Mesa.

Wednesday, March 6, 2019 - 09:15