Preparing for Native Plant Restoration on the L.A. River
Native plants at the Tujunga Wash | Photo: Justin Cram/KCET Departures
"You can't talk about the Los Angeles River without talking about its plants," says Ellen Mackey, senior ecologist on assignment to the Council for Watershed Health from the Metropolitan Water District of Southern California.
Los Angeles River revitalization has been a buzzword for a couple of years now. Its popularity has only heightened as plans were announced to restore the ecology of an 11-mile stretch on the Los Angeles River last year.
The azure and verdant photographs and renderings might be enthralling to some, but to Mackey and her colleagues it also represents a challenge. "How does one put that many seeds on the ground?"
Mackey leads the Native Seed Resources Coalition (NSRC), a group of organizations working to ensure that there is an adequate supply of locally sourced plants for L.A. River projects and other public and private projects in the watershed. The group has been working toward this mission for about three years this March, but even longer individually. "We want to make sure that local native plants are available and used in these projects," says Mackey.
The coalition includes Rancho Santa Ana Botanic Garden, the Los Angeles County Department of Public Works, the L.A. County Department of Regional Planning, as well as the Theodore Payne Foundation, the California Native Plant Society, the Army Corps of Engineers, and the Bureau of Land Management, among others. Several seed businesses also attend meetings.
It might seem an easy task to the ordinary Joe, but the reality isn't so. "The Los Angeles River Masterplan emphasizes the use of native plants in projects, but the problem is that we don't have a lot of them," says Mackey. Given the jump in Los Angeles River projects slated in the near future, the demand will only increase in the near future. Without these plants, contractors could conceivably turn to non-native plants, which require more water and manpower to maintain.
There are many reasons for the shortage in supply. Three years of drought, rapid urbanization, fire, the growth of invasive weeds, and even climate change has affected the native plant population.
Time is also an issue. Native plant restoration projects need to be planned in advance; as wonderful as it would be to have ecological restoration projects pop up everywhere, the supply for native plants must be ensured in parallel.
Though seed collection can happen all throughout the year, every species has a specific collection windows in a year, typically within the springtime and early summer. The National Park Service writes:
...a series of collections is needed to reflect the diversity of the seasons. After the seeds are collected, some require special treatment, such as several months of cold hardening or after-ripening, before they will germinate. If plants need to be propagated from plant cuttings, a general rule of thumb is to allow 18-30 months from the time the parent plants are located in the summer to the time rooted cuttings are of sufficient size to survive transplantation into the restoration site. To be absolutely sure of plant availability, containerized seedlings should be ordered 1-2 years prior to planting and bareroot seedlings should be ordered 2-4 years prior to planting. Commercially grown seed also requires ordering ahead of time.
With a major project such as the $1 billion L.A. River restoration is on the table, discussions are already happening on what types of plants will be used for the project, even though the project could be realized as far in the future as 20 years down the line. NSRC is already planning for the increased demand by ramping up seed collection of these identified species.
Another obstacle is funding. "Native plants are still considered a niche market. Most non-profit and even for-profit nurseries with native plants operate on a knife's edge," says Mackey. It means that they scrape together funds for to pay for professional, knowledgeable people to help them collect seed.
There is an ethics to seed collection, according to Mackey, which professionals with an appropriate permit would adhere to. "We don't want over-collectors and people who trample on the plant population," she says. Ethical collectors know just how to collect, where, and how much. Appropriate collection methods mean you don't harvest 50 percent of the available seed, but only 10 to 15 percent; returning to a site as much as five or six times to catch the plants at its optimal stage; then their collected seeds have to be cleaned and tested for viability. It's not guerilla collecting where people go willy-nilly on land.
Finally, the government's purchasing policies make using native plants difficult in restoration projects. According to a presentation to Native Seeds by landscape architect Mie Joness, the county relies on a competitive bid process when awarding contracts, in compliance with the Public Contract Code. It is a sound process when speaking of products that are readily comparable. In a competitive scenario, suppliers who are able to provide the same product at a lower cost wins the bid.
When speaking of native plants, however, the same cannot always be said. Mackey says that it would be better to evaluate bids based on "best value," not on lowest price, because there are other considerations for the same type of seed.
For example, a seed from 20 miles away on a coastal side of a mountain range is offered at a higher price than seed from 50 miles on the same side of the mountain rage. Though both are the same seeds, the one collected from an area more climatically similar area can be the best value because it has an increased chance of surviving to maturity.
The supplier's credentials also need to be scrutinized. It may be straightforward to provide X number of seed, but are these people qualified to plant those seeds and grow them successfully?
NSRC has been working with agencies to institute a Best Value approach. This approach includes that bidders for a project not only have the necessary seed, but have to show a record of success for past projects. "Hiring these people would probably cost more, but you wouldn't have to reinstall that landscape several times," says Mackey. The result is cost-savings for the agency and the people over the long run.
In response to these issues, NSRC has undertaken a number of projects designed to build an ecosystem that supports local native plants. The organization has compiled a Google map-based comprehensive list of Southern California nurseries that provide native plants, which county contractors could use as a resource. The NSRC site also has a working list of drought-tolerant, low-maintenance plants (such as native grasses) that can be used on landscaping projects on the Los Angeles River. Their short list provides a rundown of plants that native plant nurseries can focus on, while a more extensive list in available in its Landscaping Guidelines. "These plants so eloquently described by early explorers now need our help to survive and thrive."
Another initiative also plans to build a network of native plant nurseries in the L.A. River watershed that would focus on growing local plants. Right now, if a project requires local native plants, it needs to contract growers ahead of time, which drives the price of the specific plant palette up. If there were nurseries that already grow them, it would create a ready marketplace that would bring the prices down and would increase the probability that contractors will install local, native plants.
Right now, the Theodore Payne Foundation already has their weekly inventory of seeds and plants available online. Mackey hopes it will just be one of many nurseries that would list their inventory and its source, species by species.
Finally, the California Native Plant Society is working on a statewide certification for landscape contractors who install and maintain native plant projects. The certification would ensure that suppliers have at least a minimum knowledge of native plants. It would also help agencies evaluate bids using the Best Value approach.
"All these projects are tightly woven together," says Mackey. "We're trying to provide as much support as possible for beautiful, successful native plant landscapes that require very little water." Though relatively unheralded, projects such as these ensure the biodiversity of Los Angeles.
"We can't lose what we have here in Los Angeles," says Mackey. "It would be like burning down half your local library or randomly deleting files in your hard drive."
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