Page 8 - Sonoma County Gazette March 2018.indd

Fire Ecology for Non-Scientists: I will Survive!
Renewal for Pepperwood’s Trees and Shrubs
and our beautiful leopard lily (Lilium pardalinum subsp. pardalinum) as well as various iris species. As explained in a recent issue of the California Native Plant Society’s Fremontia magazine:
Fire-nspired seed pods bursting PHOTO by Jean Pawek
Fire Follower - PHOTO by Vernon Smith
By Sandi Funke
Though many of us were
taken by surprise by the res last fall, if the plants that live
at Pepperwood could talk I
bet they would say they were not that surprised. In fact, I
bet they would say they were prepared. Our local vegetation has evolved a number of clever ways to regenerate after re. In res of low to medium severity, many of our plant friends
Sprouting
As you probably recall from
elementary school plants
produce their own food through photosynthesis. Unlike us, plants cannot go get food. They produce green leaves, which contain chlorophyll and, through photosynthesis, which requires water and sunlight, make sugar. If a tree loses its leaves, it cannot feed itself.
Sprouting is one way plants can regenerate
after a re and begin quickly feeding themselves.
We are already seeing many trees and shrubs at
Pepperwood sprouting. Just two weeks
after the res we observed coast live oak
(Quercus agricolia) lea ng out. Arm-like shoots
reaching for the sun can arise from dormant
buds above the soil surface or even below
the leaf litter. Many of our chaparral plants
are already sending up such growth. The
charming toyon (Heteromeles arbutifolia) sends
up stump sprouts around the base of the plant
as do manzanita (Manzanita spp.), leather oak
(Quercus durarata), and coyote brush (Baccharis
pilularis). Blue oak (Quercus douglasii), black
oak (Q. kellogii) and Oregon white oak (Q.
garryana), all found at Pepperwood, can
also regenerate with stump sprouts and growth
from root crowns. The root crown is the point
at which the stem and the roots meet. Tanoaks
(Notholithocarpus densiflorus), though not actually
oaks, can regenerate in the same manner. Coastal
redwoods (Sequoia sempervirens) can also regenerate
from their root crown. You may have observed
this if you have ever come upon a redwood tree “fairy ring.” Each
of those, sometimes large, trees in a circle is a sprout from the same root crown. Amazingly, coastal redwoods also have dormant buds all along their trunks that spring to life from under the thick bark after a re, carpeting the entire burnt trunk in a brilliant lime green.
Geophytes are a group of plants that grow from a type of thick underground storage organ. The leaves, stems, and owers of geophytes emerge and then die back leaving little sign of their presence. The secretive storage organs of these plants are described generically as “bulbs” but include corms, rhizomes, true bulbs, and tubers. Pepperwood is home to quite a few geophytes including soap root (Chlorogalum pomeridianum), mariposa lily (Calochortus luteus),
“Because of their underground storage organs, geophytes are well adapted to withstand the e ects of re. Growing deep in soil, the bulbs, corms, and rhizomes are protected and insulated from the heat. Fire bene ts geophytes in a number of ways, and are actually
dependent on its regular occurrence.”
have a ghting chance to not only stay alive but also thrive. Read on to learn what amazing mechanisms these verdant survivors exhibit to reside in our re prone ecosystem.
Like just
hanging out in
an underground bunker during a disaster, geophytes can emerge and take advantage
of the post- re ecosystem after the smoke has cleared. At Pepperwood we are already seeing large bursts of early germinating soap
lily and death camas (Toxicoscordian fremontii) taking advantage of the re and promising brilliant white blooms in spring.
Seeds
Seeds are another way shrubs and trees renew their plant community after a re. Some seeds
can well withstand re while others lay in wait
in the soil needing re to germinate. The seeds
of our chaparral shrub chamise (Adenostoma fasciculatum) actually need heat to germinate. Sticky monkeyflower (Mimulus aurantiacus) seeds can also be coaxed to germinate by heat or smoke. A manzanita (Arctostaphylos spp.) seed’s hard seed coat requires a distrurbance such as re to break the seal and begin to germinate. Several owers we hope to see for the rst time this spring require re. We’ll be writing about these in a future blog. Acorns in the canopy of oaks can survive low severity res, but once they are charred, they cannot sprout. However, the ones that remain viable and un-burnt may have a better chance of survival as re can reduce leaf litter, which can choke out baby oak seedlings by preventing acorns from reaching the soil surface as they germinate.
Rhizomes, Corms, and Bulbs
Large oak have thick reproof bark. Redwood trees are very re resistance due to their thick
bark. In Pepperwood’s Redwood grove, we have found... Douglas r trees are said to be moderately re resistant depending on the intensity of the re.
8 - www.sonomacountygazette.com - 3/18
At Pepperwood, we call the sprouts coming from below the leaf litter “stump sprouts.”
Over the next few months and years Pepperwood’s forest and chaparral ecosystems will be reviving themselves in a number of ways. If you want to see it for yourself join us for an upcoming public hike.
Fire resistance
Corms are rounded thick underground stems that are often scaly. If you are a gardener, you may have planted corms before in the form of crocus or gladiolus. Rhizomes are plants with thick horizontally growing stems.