The Central Coast has received a record-breaking deluge of rainfall – with over 4 inches of rain on February 17th alone. Any weather event will bring change to an ecosystem, whether it is drought, frost, fire, or rain. By now we’ve been well acquainted with how our regional ecosystems have responded to drought and fire. The invasive annuals have died back quickly, leaving dormant natives to stand alone through the sun and heat to provide shelter to the wildlife. Wildfires like the Zaca Fire cleared away any sign of life along that stretch of the 101, but now the ecosystem has been reset, and quick growing pioneer species are taking their chance to grow while the slow growing and hardier shrubs patiently reestablish their dominance. But how does rain impact our ecosystems and our attempts to restore it? After so long, the memory of rain seems hard to fully recall, like a mirage that shimmers and dissipates as we further investigate it. Luckily this year has given us a crash course to remind us.
With the rain arises a new array of benefits and obstacles. Much like the harsh drought helped eliminate poorly-adapted invasive species, yet made the establishment of new natives difficult; rain offers a gradient of impacts.
Rain, of course, helps plants grow - this is hopefully not new information - yet after a rain, it’s often a race for seeds and dormant plants to grow and take up more sun and nutrients than the plants around them. Unfortunately, many non-native invasive species are highly adapted to responding quickly and growing much faster than their native competitors. At Hammond’s Meadow in Montecito, CIR staff have been battling wave after wave of invasives that spring up after each rain. We’re working to maintain what’s known as a “Grow-Kill” cycle, to deplete the invasive seed bank as we apply for permits to restore the property. After each rain, we must respond quickly and cull the new growth before they can flower and go to seed, and we’ve been using a number of organic known weed killers like oils from orange peels, cloves, and cinnamon, in addition to directly cutting the weeds with a scythe. However, once natives are able to establish themselves, they are able to maintain their dominance over the invasive weeds because most of our native plants live year-round and simply go dormant in droughts, but spring up in response to rain without having to build new root structures. A number of our project sites have responded exceedingly well to the recent rains.
On East Anacapa Island, volunteers and CIR staff have been working hard to eradicate ice plant and replace it with natives. As discussed above, if we can plant natives in place of removed invasives, it will help prevent the invasives’ reestablishment. On the western end of East Anacapa Island near Inspiration Point, CIR put a lot of work into eradicating ice plant and planting coreopsis among the dead ice plant. Unfortunately, our timing was not ideal as we planted four years ago, ahead of a four year drought. It was thought that the coreopsis would die off and the project would be deemed a failure, but on a recent trip out to the island in January, we found tiny coreopsis plants pushing their way up through the net of dead iceplant. Needless to say, we’re incredibly happy about this.
Additionally, the rains have vastly helped in the establishment and maintenance of newly planted restoration sites in areas like Burton Mesa, San Nicolas Island, and the San Marcos Foothills. Rather than devoting time and resources to getting out and ensuring the plants have the water they need to establish themselves enough to survive a drought, we can put our focus on establishing new restoration sites.
However, the recent torrential rains have had much more of an impact than just allowing plants to grow. For quite some time now, we’ve been working to survey for, and eradicate tamarisk along the Sisquoc River. Yet as we plan a date to head out with the mule team from Los Padres Outfitters, each time our plans have been canceled due to rain and we’ve had to reschedule. Rescheduling is one thing, but on a much more devastating scale, these rains have led to floods.
Anyone that regularly receives and reads our emails will know that we’ve been fortunate enough to do a lot of work on San Nicolas Island. We’ve accomplished a lot out there, with over 30,000 plants grown on the island for various purposes - one of which has been to reconstruct habitat for the threatened island night lizard, habitat that they have already begun to use. It’s with these accomplishments in mind that we can accept without too much frustration that the torrential downpour washed one of our newly planted wetland restoration sites to the sea.
As the recent weather events have demonstrated, ecosystems are dynamic and constantly changing, and there are seldom perfect conditions for habitat restoration. Critics of restoration often cite that if native habitats are well adapted to the regional climate and ecosystem, then we should not interfere and allow nature to take its course in returning the ecosystem to its native state. While this sounds good in theory, it is not that way in practice. Ecosystems can exist in multiple stable states that resist change. Originally, our native ecosystems would have been able to resist encroachment from invasive species, but with European induced disturbances like land clearing, grazing, logging, or road-building, the balance of our native ecosystems was tipped and novel invasive species were quick to fill the spaces due to the lack of natural bio-controls for such species. Conversely, to restore habitat to their native stable states requires effort to overcome that threshold. This means clearing invasives, and watering natives so that they can take root, and controlling erosion, and putting up barriers to grazing around new plants. These things are not done because our native plants are not adapted to drought, rain, fires, or herbivory, but because proactive work is needed to push the ecosystem out of the invasive state and into the stable native state.
Just as we’ve done habitat restoration through the drought, we’ll also continue through any amount of rain. Part of restoring habitat is learning to work within the wide range of ecosystem dynamics. It’s learning to manage the unmanageable. It’s acknowledging that rain or shine, it’s always a good day for habitat restoration.