Annual
precipitation:
20-60 inches
Common Animals:
Steller's Jay, Deer, Gray Squirrel, Raccoon, Badger
Common Plants
Bigleaf Maple (Acer macrophyllum), California Bay (Umbellularia californica), Christmas Berry (Heteromeles arbutifolia), Coulter Pine (Pinus coulteri), Tan-Bark Oak (Lithocarpus densiflora),, Canyon Live Oak (Quercus chrysolepis), Black Oak (Quercus kelloggii), Coast Live Oak (Quercus agrifolia), Madrone (Arbutus menziesii), California Hazelnut (Corylus californica), Coffeeberry (Rhamnus californica),
Soil and climate notes:
Very diverse, but usually acidic clays to loam
The Mixed Evergreen Forest plant community is found mostly in the northern coastal mountains of California, though extending down to the central coastal mountains. Some of the component species include Tanbark Oak (Lithocarpus densiflora), Madrone (Arbutus menziesii), Douglas Fir (Pseudotsuga menziesii), California Bay (Umbellularia californica), Bigleaf Maple (Acer macrophyllum), Canyon Live Oak (Quercus chrysolepis), Black Oak (Quercus kelloggii), Coast Live Oak (Quercus agrifolia) and California Hazelnut (Corylus californica). This forest is filled with leafy trees and few conifers. This makes for a softer looking forest. However this forest is not really that soft. There is often a dense understory of brush and a canopy containing several species of oak (It's so dark you have to use a flash in the middle of the day to take a picture.)
An
understory of Oregon
Grape (Mahonia pinnata), Redtwig
(Cornus stolonifera ) or American
Dogwood (C. sericea), Ninebark
(Physocarpus capitatus) at the southern edge of the
range of Mixed Evergreen Forest.
The rainfall in the Mixed Evergreen Forest can vary anywhere from
25 to 65 inches. The temperatures within the Mixed Evergreen
Forest are mild although not as mild as the nearby redwood
forest. This plant community is like Seattle, wet and drippy many
weeks of the year, and days commonly do not warm up. Lows below
20F are very uncommon, highs above 90F are very uncommon. A
winter day can have a low of 28F and a high of 40F. A summer day
can have a low of 55F and a high of 85F. Humidities are almost
always 50-80%.
Many of the components of the Mixed Evergreen Forest are also found in the Yellow Pine Forest as well as the Redwood Forest. The Mixed Evergreen Forest has a wonderful fresh smell given off by the aromatic California Bay (Umbellularia californica) (or California Laurel ) trees. The dense brush and thick evergreen trees are an excellent habitat for birds. There is an abundance of food for wildlife in the form of various acorns as well as California Bay seeds. See http://www.laspilitas.com/bird.htm for more bird information. In some areas there exists nearly solid serpentine soils. Where the conditions would normally dictate Mixed Evergreen Forest, there is a mosaic transition, depending on soil depth, the amount of serpentine rock, and location in California, to Northern Coastal Scrub, Coastal Sage Scrub or Chaparral and then, to a serpentine grassland. We do not separate this as a community because the serpentine plant community is usually the plant community that is supposed to be there, minus the plants that cannot tolerate serpentine. On real 'raw' serpentine areas this will be nearly all seasonal forbs, grasses and bulbs that occur in the adjacent Northern Coastal Scrub, Coastal Sage Scrub, Chaparral, or Mixed Evergreen Forest. The serpentine soil just brings the plant community to extremes. In the Mixed Evergreen Forest the trees and shrubs Coulter Pine (Pinus coulteri), California Bay (Umbellularia californica), Coffeeberry (Rhamnus californica), California Lilac (Ceanothus papillosus or C. foliosus) give way to bald spots full of bulbs such as Mariposa Lily (Calochortus spp.), and perennials like Coyote Mint (Monardella villosa ), Checker (Sidalcea spp.), Creeping Sage (Salvia sonomensis) and many others. When transpiration (loss of water from plants) exceeds available soil moisture plant communities change. This is minor in Coastal Sage Scrub and very minor in Northern Coastal Scrub but very limiting in Chaparral. Some factors that can affect this moisture limitation can be summer heat, rainfall, summer fog, blowing winds, humidity, depth of soil, etc.. For one example, Mixed Evergreen Forest will change to Chaparral under these conditions. BUT, you can often move Chaparral to Mixed Evergreen Forest!
The Mixed Evergreen Forest has a lot of dense shade. However,
there are still plenty of flowers. One of my personal favorites
is Ocean Spray
or Cream Bush (Holodiscus discolor). The buds are a
creamy pink. When the flowers open they are cream and then they
slowly turn a toffee color. The plant is very soft and can be
used as babies breath in flower arrangements.
To create a Mixed Evergreen Forest in your garden you need fairly
mild temperatures. Many of the dominant species such as the
Bigleaf
Maple (Acer macrophyllum),
Tan-Bark
Oak (Lithocarpus densiflora),
and the California
Bay (Umbellularia californica)
can not withstand hard freezes. However, you can grow these
species, where temperatures often drop into the teens, by
planting them under cover of oaks or on the lower side of
structures. Remember, because cold air is denser it settles into
the lowest areas. It is coolest in canyons and in low pockets. So
if you live in a cold climate try to avoid planting our mixed
evergreen forest species in these areas. When planting these
species keep in mind that not all species in the mixed evergreen
forest are evergreens. A few species are deciduous. You want to
start with some overstory plants first such as several oaks, the
California Bay, maybe a Madrone, mixed in with and protected by
Ceanothus species (if you are in the southern part of the state
and have hotter summers, start with the Ceanothus and then after
a year or so, plant the trees on the north side and in the shade
of the Ceanothus ), and as they grow and shade increases, then
you can plant the understory plants. Remember to use plenty of
mulch after planting your mixed evergreen forest. This will help
to keep the soil healthy and also to retain moisture. Water your
plants well when you first plant them as this helps to settle the
soil around the roots and rehydrate the soil. ( Do not pack or
work the soil when it is wet as this will remove needed air from
the soil; see planting
guide at http://www.laspilitas.com/planting.htm)
Also, one item that we don't think about too much is that as plants grow they can actually change the climate, just by being there. So, if you have a dry, hot, sunny, open spot and the more trees and shrubs (such as from the Mixed Evergreen Forest) that you grow, the more the climate will change and your spot will be moist, cool, shady, and closed-in!