Re: Mediterranean Oregon?

---

David,

 

We are talking about a very long gradient both for temperature and rainfall/seasonality, and you're correct to note that the relative length of wet and dry seasons do matter.

 

But, depending on what you call "significant rainfall", at least one year out of two, most stations in the maritime Northwest  [Victoria BC south through Oregon, west of the Cascades] hardly get a significant rain [enough to penetrate the soil, that is more than 1 cm in one storm] between late May and early October.  Soil moisture deficits are much more than 6 to 8 weeks in the region, probably averaging at least  15 weeks of the growing season in western Oregon.  Further, our summer humidity is quite low, another reason that summer-rainfall plants do poorly here and another reason we look to Mediterranean regions for plant material. 

 

loren russell

corvallis, oregon, usa

 

-------------- Original message --------------
From: david feix <davidfeix@yahoo.com>

> I always find it slightly amusing to here an eight
> week long dry season equated to a 6 to 8 month long
> dry season such as we have here in the San Francisco
> Bay Area. Although we certainly share some similar
> plants such as the ones mentioned, most of these are
> best adapted here in areas that receive considerable
> additional summer water through fog drip from the
> native conifers such as Pines and Coast Redwoods, and
> will not survive without this in more inland areas or
> without the fog drip. Eucalyptus globulus forests
> also serve quite well on ridge tops to help catch and
> drip fog down to the understory plantings, and can
> create their own local cloudforest vegetation where
> they are sited to catch the fog.
>
> Much shorter dry seasons can ! certain ly be similar to
> mediterannean climates, but are not exactly equivalent
> and may mislead people who are not really growing the
> same plants under the same conditions. Arbutus
> menziesii usually will not survive here in coastal
> California unless planted in shaded north slope
> conditions or areas outside summer fog mixed evergreen
> forests. No significant rainfall between mid May and
> mid October is pretty tough on plants that aren't
> adapted to this.
>
> --- Otter Point wrote:
>
> > Scientists and gardeners always refer to the East
> > coast of Vancouver
> > Island and Gulf Islands as a Mediterranean climate.
> > Our native plants
> > and trees (Garry oak, Arbutus menziesii, Manzanita,
> > Holodiscus, etc.
> > etc., all thrive with 7-8 weeks of little or no rain
> > every summer.
>! ; >
> > Diane Pertson
> > Vancouver Island
> > _________________________________________________
> > ----- Original Message -----
> > From: "Sean A. O'Hara"
> > To: "Paul Russo"
> > Cc:
> > Sent: Monday, May 15, 2006 11:48 AM
> > Subject: Re: Mediterranean Oregon?
> >
> >
> > > At 07:08 PM 5/13/2006, Paul Russo wrote:
> > >>Last summer while vacationing in Eugene Oregon, I
> > noticed many
> > >>varieties of Mediterranean plants...tall palm
> > trees and agaves etc. I
> > >>was quite suprised. The summer climate felt very
> > Mediterranean-sunny,
> > >>dry. I stopped by the U. of Oregon library and did
> > alittle research
> > >>and discovered that western Oregon is consider! ed a > > Northern
> > >>Mediterranean climate zone, about the same
> > latitude as Genoa Italy.
> > >>Palm trees in Oregon? Yes, all over the place, in
> > Portland too.
> > >>Several Mediterranean palm species thrive in
> > Seattle and Vancouver BC
> > >>as well. When I told my friends back in New
> > Jersey, I got sceptical
> > >>looks, I don't think they believed me.
> > >>Well, a few species of palm grow in Southern NJ
> > too...
> > >>
> > >>Cordially,
> > >>Paul Russo
> > >
> > > Hi Paul -
> > >
> > > Technically, according to most climatologists, the
> > mediterranean
> > > region does indeed extend into Oregon from
> > Northern California. The
> > > California Floristic Provinc! e, whic h basically
> > represents the
> > > mediterranean climate region on the west coast,
> > extends into North of
> > > California into Oregon and South into Baja
> > California. The Rogue
> > > River of Southern Oregon definitely has a very
> > 'California look' with
> > > many of the plants typical of the Province.
> > >
> > > Portland, at the Northern edge of Oregon, while
> > often seen as very
> > > similar to a mediterranean climate, is generally
> > not classified as
> > > such. There are many proponents of
> > 'reclassifying' this area, notably
> > > Sean Hogan of Cistus Nursery and Landscape Design
> > (www.cistus.com),
> > > but even he bills his business as "your home for
> > zonal denial". The
> > > recent observations of global warming ! worldwi de
> > may be responsible
> > > inspiring this type of thinking. There are a
> > variety of
> > > 'mediterranean like' places in the world -
> > Vancouver Island in British
> > > Columbia (farther North still), being in the rain
> > shadow of the
> > > Olympic Peninsula, creating relatively drier
> > summers than adjacent
> > > areas, is one of these places.
> > >
> > > Regarding Portland being the same latitude as
> > Genoa, Italy - latitude
> > > alone does not achieve the mediterranean climate
> > effect. Genoa is a
> > > port on the warm Mediterranean Sea, which
> > increases the winter and
> > > summer temperatures of the landmasses that border
> > its shores. The
> > > Riviera, French and Italian, are also backed by
> > the Alps, ! which h old
> > > the cold northern effect back. This area is the
> > most extreme latitude
> > > (close to the poles) of all the mediterranean
> > climate world regions
> > > because of these factors. In fact, the warm
> > temperature of the
> > > Mediterranean Sea that is responsible for the
> > mediterranean climate
> > > effect extending so far east (all other
> > mediterranean regions lie
> > > along the oceans that define them).
> > >
> > > Other similar regions can certainly learn from
> > techniques we find
> > > useful in the mediterranean climate, and even
> > within the technically
> > > accurate definition of the region there are
> > numerous microclimates
> > > which have their unique idiosyncrasies. We all
> > need to evaluate the
> ! > &g t; site in which we are creating a garden and use
> > what approaches make
> > > the most sense for our situation.
> > >
> > > I hope this helps answer your query.
> > > Regards,
> > > Seán O.
> > >
> > > h o r t u l u s _ a p t u s - - - - - 'a garden
> > suited to its purpose'
> > > Seán A. O'Hara --- sean(at)gimcw.org ---
> > www.hortulusaptus.com
> > > 1034A Virginia Street, Berkeley, California
> > 94710-1853, U.S.A.
> > >
> >
> >
>