Simple Rule of Biogeography for California Floristic Province

Valleys—Whether small/narrow or big/broad, are the domain of deciduous trees, farms, fall color, rivers, home, and (believe it or not) the most abundant and diverse “wildlife”, at least originally.  Suited for agriculture and residential uses.

The only major difference within valley ecosystems is between:

1. narrow, small valleys less than 1 km wide or so are/were solid riparia, whereas
2. wide valleys like Santa Clara and Great Valley and Salinas are divided into: 
   1. riparian strip along river
   2. often seasonal marshes loosely connected with river
   3. wide outlying zones of “grassland” which can include grassland proper, savannahs (with deciduous oaks, sycamore etc.), and/or “flower fields” on thin soils

Uplands—(hills etc. up to several thousand foot elevation, depending on latitude) are the natural domain of:

1. coastal conifer/misc evergreen forest (in northern coastal belt)
2. chaparral
3. open “foothill woodland” (blue oak/digger pine/buckeye etc.) in interior 
4. evergreen oak woodland/forest

Any of the above can be interspersed with various kinds of meadows and “flower fields” and are often interdigitated with each other as well.  Bottom line or common denominator of uplands in California Floristic Province is evergreen trees, whether conifer or broadleaf or both.

Naturally suited for grazing and logging as main economic sources.

Southern Coastal Plains—Either a subtype of  “Valley” or a type of its own (describe).  Originally mostly grassland and coastal scrub?

Highlands—(above 4,000 ft. or so—not the subject of this book) are the domain of conifers mainly.

Corollary:  If you live in a valley, make your plantings mainly deciduous, and avoid tall, pyramidal conifers.  If you live in the hills, keep to an evergreen Mediterranean theme, with conifers if you live in a conifer region and broadleafs if you live in a broadleaf or chaparral region.  Avoid deciduous plantings.

Also, concentrate on deciduous plantings if you live in a northern or cool region.  Concentrate on subtropical plantings if you live in warm (especially frost-free) region, mainly the Southern California crescent, from Santa Barbara south.