North American Fruit Explorers mailing list at ibiblio

[Elizabeth Hilborn <ehilborn@mebtel.net>]

Mary, I do not think that humidity is the key variable.  I live in a 
very humid zone 7. They are intrepid invaders here in both disturbed and 
intact forest and grasslands, I manage them, but cannot eradicate them.

I would not plant one on purpose.

Betsy Hilborn
Zone 7a (again!), NC

On 3/27/2014 3:02 PM, Mary Yett wrote:
> Whether or not a plant becomes invasive depends a lot on the local climate.
> Here on Manitoulin Island, Ontario in a humid zone 4 with a maritime
> climate ( cool summers), none of the Eleagnus spp have ever become a pest
> sp. In hotter, southern Ontario, there are areas where Autumn Olive, for
> example , has naturalized as a pioneer sp.
>
> In humid climates,these pioneer spp typically establish only on disturbed
> and/or infertile ground. Their role in the natural succession of
> temperate,humid ecosystems is to fix nitrogen from the air, improve the
> soil, provide a bit of shade for other, taller trees to germinate in and
> then die out when the taller trees shade them out.
>
> Our dominate agriculture system keeps succession at the ruderal stage
> (early annual weeds, ie annual crops, and pioneer woody spp) by the use of
> constant disturbance (plowing annually,mowing roadsides, etc). This creates
> good habitat for pioneer spp, both native and introduced.If left alone in a
> temperate humid climate, Eleagnus spp just do their work and then fade away
> and do not have a negative impact on the native ecosystems.
>
> I realize that in a dry climate, esp with poor soils, the picture can be
> very different.
>
>
> On Thu, Mar 27, 2014 at 1:00 PM, Robert Stanton
> <robert.l.stanton@gmail.com>wrote:
>
> > > Just out of curiosity, does anyone on this list consider the invasive
> > > potential of the plants they use?  I dedicate a significant portion of my
> > > time to removing autumn and Russian olive from landscapes here in the
> > > midwest, and it's always disheartening to hear others actively planting
> > > more of what needs to be removed to maintain diverse natural plant
> > > communities.
> > >
> > > Robert
> > > __________________