Local Hero in Habitat Restoration - Arne Johanson

Today I had the pleasure to visit the site of an ongoing habitat restoration. Since 2004, Arne Johanson and a handful of volunteers has painstakingly and lovingly tipped the balance from invasive weeds to native plants on nearly 1000 acres of the Artesian Creek watershed in San Diego County. Arne uses a recruitment technique, called the Bradley Method, developed by two sisters from Australia.  The method is remarkable for its logic and cost effectiveness. Traditional habitat restoration entails killing weeds and then planting or seeding native plants. Without constant vigilance areas such as these are quickly overtaken by a new crop of non-native weeds. The irrigation, and costs for plants, plus labor, is often prohibitive. Not to mention, the plants or seeds used are often from different localities not as suited for  the unique conditions of the site they are planted.

Restored Area of Artesian Creek

Arne has perfected his technique which relies on the recruitment of native propagules that naturally move in once the biomass of invasive weeds is reduced. He is strategic, and prioritizes weed removal to areas that have established populations of native plants, so seeds of the native plants are able to move in and fill in the vacuum created by weeding. While it may appear that wholesale removal of a large area of weeds in a short amount of time is an effective method to revegetate acreage, but the weedless expense is quickly reengulfed if native plant communities are not close by. The Bradley Method relies on the power of Mother Nature to heal a disturbed landscape with a little nudge from Arne and his band of volunteers. A guiding principle for this type of restoration is never to weed an area larger than can be recolonized by neighboring native plants. Arne and his team accomplish all this on a tiny annual budget of $500-$1000. He has expanded his efforts to include Black Mountain, Lusardi County Park, Rattlesnake Canyon, and Poway Lake.
Ask Arne why he fights the good fight, and he will tell you, "It needs doing, and I can do it" it's his short answer to the philosophical question. The long answer is his heart felt joy upon seeing animals recolonizing an area, or seeing a new field of wildflowers, where there once was weeds. He says he will continue to wage this war,  "as long there are people able to keep at it."
Arne as a true hero! After many years of hard work he was recently nominated as a finalist for the Cox Conserves Heroes award. Let's hope he wins! Good job Arne and keep up the unbelievable work you do!

Rough Geographic Area of Arne's Restoration 

We botanized as we appreciated all that Arne and his team have accomplished. I attempted to write down most of the plants we saw, and here are some of the highlights:

Eriophyllum confertiflorum

Cneoridium dumosum

Scrophularia californica

Calochortus splendens

Malacothamnus fasciculatus

Antirrhinum nuttallianum

Dudleya pulverulenta

Mimulus aurantiacus (could be variety puniceus)

Plant it for the Bees: Ceanothus 'Ray Hartman'

Ceanothus 'Ray Hartman' is one of our most reliable, and garden adaptable, native shrubs/trees. This cultivar, is a blending of the coastal, Ceanothus griseus and the Catalina Island tree, Ceanothus arboreus. Developed in the late 1940s it has become a well known and dependable performer in the California coastal garden. Ceanothus griseus gives the leaves of the tree revolute leaf margins and bluer flowers than C. arboreus alone. This vigorous and fast-growing plant can attain 10 feet in a couple of years in my experience, and can

top out at about 20 feet tall and almost as wide. The buds will fool you because they are pinkish, but open to medium blue, large clusters of small flowers, that make you say, "ahhh."A large mature tree in full bloom is a sight to behold, and it will have you calling up local nurseries scrambling to find Ray, otherwise known as, "Mister Dependable." The reason it is an old, widely planted, and commonly occurring ceanothus or California lilac is because Ceanothus 'Ray Hartman' will not "up-and-die" in typical garden watering regimes like other species of Ceanothus are known to do.

Remember, Ceanothus are pioneer plants, and survivors, and for the most part cannot tolerate watering that doesn't resemble the precipitation rates of their native habitats. Ceanothus 'Ray Hartman' seems to be a bit of an exception to this rule--especially--when it is newly planted. It will gladly accept most watering and reward you with luxuriant growth. The fast growth comes at a price, however, and causes problems like shorter life span, wind throw, and the aborted development of strains of the symbiotic filamentous bacteria, Frankia. Ceanothus sp. are actinorhizal plants that fix nitrogen with the help of root-forming nodules of Frankia, much like the more familiar legumes and rhizobium bacteria.

Strains of Frankia are widespread and persistent in California soils even without the host plants being present. They are also important in many other ecosystems where nitrogen is limited. Pioneer plants are important to fix nitrogen, so that other plants can get established in depleted soils. In Southern California, frequent fires deplete nitrogen and Frankia are important to hasten the reestablishment of populations of plants. Studies in southern California have identified 12 distinct strains of Frankia. Climate, geographic location, soil pH, and host species present are all thought to influence the identity of Frankia strains in a given area. Birds and water are known dispersers of Frankia. The bacteria also form relationships with other pioneer plants in the Genera: Alnus, Rhamnus (Frangula), and Eleagnus.  Unfortunately, when Ceanothus are pampered, Frankia have low levels of nodulation, this was shown in several greenhouse experiments that failed to yield the high rates of the sought-after intercellular infection of Ceanothus roots.

High Frankia infection rates improve growth, foliar nitrogen, and survival rates of Ceanothus. Because of this, it may be best to give Ray a little tough love and don't pamper him too much. Ceanothus have a undeserved reputation for being short-lived. Ceanothus tend to live longer and don't flame out at a young age when their irrigation rates are tempered.

While trees in full bloom are the stuff of dreams for humans, bees share that enthusiasm. To see a tree in bloom is to hear the excited buzzing of many bees gorging themselves on the bounty found in the little tiny flowers. Ceanothus are hands-down among the most favored bee plants in the California garden. I grow them as much for the anticipated hum of bees, as for the beauty of the blue corona of flowers. Non-native honeybees, as well as, native bumblebees, and native Halictid bees are big fans, and come from far and wide for an opportunity to partake. In the words of UC Berkeley urban bee entomologist, Dr Gordon Frankie, "Bees adore this plant!" Flowering Ceanothus are excellent and important pollen sources for bees. In my garden I consider it my duty, as well as, my pleasure to provide the finest that nature has to offer for my pollinators--especially for my bees. Ceanothus species do so many things well: they provide ravishing beauty, exceptional pollen for bees, and the fruit feed many species of birds. Plant Ceanothus and instantly attract wildlife that make your garden so much more than just pretty plants!

Lets Do This!

We live in Southern California. Few places possess the biological richness of our home. More species live here in San Diego County than just about anywhere in the United States. We are so lucky! One way we can help protect the large number of unique species is to landscape our homes with native plants. Think about it. Millions of years have honed the relationships between the endemic flora and fauna to the perfection that exists today.

But look around - what plants do you commonly see in your community? That's right, just a small number of exotic plant species from the big box store exist in nearly everyone's landscapes. The nectar from that tropical hibiscus or rosemary is not nearly as nutritious for local hummingbirds and bees as is the nectar produced by natively occurring Salvia mellifera or Phacelia campanularia. Local plants offer optimal nutrition for local fauna. Not only that, but exotic species are often poisonous to our fauna. For example, Nandina berries, although eaten by local birds, may kill them if consumed to excess. An opposite example of this is between our native Aesculus californica and honeybees--an exclusive diet of pollen and nectar from this plant will kill or disfigure the progeny of the honeybee. Honeybees are not from San Diego they originated in Europe and did not evolve to partake of our native Bottlebrush. Lets give our local fauna the local plants that offer them the chance to thrive.

Salvia mellifera

But, you say, my Pyracantha has fruit that the birds relish. That may be true, but recent studies show that not only is the nutrition superior in local plants, but the phenology or timing of the plants makes all the difference to the reproductive success of the creatures that evolved to eat the plants. Meaning that, even though a species of bird will consume fruit from non-native plant species their reproductive fitness is decreased just enough to negatively affect the birth rate. Both the timing of the crop and the nutrition of non-natives are inferior to the native species.

Phacelia campanularia

So we have the excellent nutrition native plants provide, plus native endemic plants are drought tolerant. In San Diego we typically get less than a foot of rain a year, and all of it in the months of winter and spring. Native plants have evolved adaptations to be able to survive on little water in the colder months and no water in the summer. Better yet, using locally sourced native plants fine tunes the drought tolerance to the same conditions as exist in your garden at home.

Aesculus californica

The biological richness of San Diego County means we have a large number of species of plants to chose from. And the great thing is these plants are gorgeous and occur nowhere else in the world! So lets do this! Lets plant natives, lets bring back the waning populations of birds, butterflies, and bees. We have the power to keep San Diego biologically rich and diverse.