Anybody have any views on the wisdom of planting cultivars of native plants in supposedly 'natural' areas? Think carefully - there are hidden issues here!
In ecological restoration we try to use seed that has been collected as near the original site as possible. Often we limit the material to collections from with 15, 25, or if necessary 75 miles from a site. There are some sound reasons for this policy.
A good example locally is prairie grass. Prairie grasses are much more common in Nebraska than in Illinois. Nebraska prairies continue to be used as grazing lands, where as Illinois prairies have nearly been completely converted to corn. When people started restoring prairies they purchased grass seed from Nebraska for restorations in Illinois. What they soon discovered was the grasses from Nebraska were considerably different from the same species in Illinois. I have even been told they bloom at different times. Some people noticed the Nebraska variety was soon over taken by the better adapted native variety. In Iowa, the Nebraska variety was actually able to out compete the native variety. This can cause problems.
Here is an example. When doing restoration a native willow sp. was planted to stabilize a stream bank. Very observant ecologists noticed that insects which ate this willow species in adjacent areas where not consuming the planted variety.
The point is, local interactions have developed that are very important. Material introduced from distant sources often will be out compete by better adapted local varieties. In other situation the introduced material will have an advantage since local herbivores, predators, and parasites will not eat it. This can cause an introduced variety of a native species to act in an invasive manner.
In summary, no I would not plant cultivars in a remnant natural community. However, it should pose no problem if planted in a pot in my backyard.
James
Comments
Re: Planting Cultivars of Native Plants In Wild Lands
Re: Planting Cultivars of Native Plants In Wild Lands:
I may also add that the introduction en masse of non-diversified genetics (i.e. a single cultivar) in any natural environment defeats the underlying basis of that species adaptation in the future. Without a diverse gene pool to evolve from, adaption through evolution is severely curtailed.
Regarding a cultivar in the garden:
On one hand, one might argue that even planting a non-native origin species cultivar in the garden, amidst its natural native counterparts nearby, is fooling with natural genetics. Pollen from the non-native might hybridize with the native, and vice versa. On the other hand, such a relatively subtle introduction to the gene pool (if at all) could be considered advantageous, by increasing the adaptive possibilities of the species. In my opinion, such a concept is best discussed in theory only, as its practical implementation, one way or the other, would be extremely subjective.
Re: Planting Cultivars of Native Plants In Wild Lands
Bob,
What about pollination?
Yes, of course it will pose a "problem".
Actually, I am 60 miles or more from the nearest population. Therefore, pollen transfer would be almost impossible.
Your concern about pollen transfer is a valid point. The distance of my garden from any natural area makes gene pollution unlikely. The only possible exception would be the Asclepias tuberosa that was planted at my house before I purchased it. The pollen might not make it 20 miles, but through successive colonization from the seeds the genes might travel that distance. I do not know whether this Asclepias is a local or distant genotype since I did not plant it. However, Milkweed seeds disperse so widely that there was undoubtedly strong gene flow between distant populations. That was, before the habitat was fragmented.
I realize your question was not truly made out of concern for ecological impacts from gene pollution. If you must hurt me for pointing out the damage introduced species are causing, then you have succeeded in your endeavor.
James
Re: Planting Cultivars of Native Plants In Wild Lands
Just such a gene transfer is of concern in Nevada I refer you to this posting about Penstemon rubicundus, I recently posted.
What about pollination?
Yes, of course it will pose a "problem".
Bob