Notice: I've taken a part-time job, and it's definitely affecting my blogging time. I'll continue to add content here as often as possible. Pertinent guest posts are always welcome.


Thursday, December 4, 2008

Plants Take A Hike

by Joan H. Young

Even Plants Use Wildlife Corridors (Trails)

It’s been known for quite some time that natural corridors, trails being an example, can help wildlife move safely from one area to another. Even seed dispersal of some types is aided by corridors.

Researchers at Washington University in St. Louis wanted to know more about how plant movement in corridors happens. They got some predicted results, and one big surprise.

Three common means of seed dispersal include ingestion and defecation by birds, wind dispersal, and unassisted dispersal. In unassisted dispersal the seeds fall near the parent plant. The unassisted seeds are not encased in appetizing fruit or possessing fine hairs or wings which allow the wind to move them.

The study accurately predicted the movement of seeds by the birds along the corridors. Researches did not fare so well with their notions of what would happen to the wind-dispersed seeds. The corridors enhanced the effects of the wind much more than what they expected. "In hindsight, this makes a lot of sense,” said researcher Ellen Damschen. “Wind can be channeled between physical structures. For example, think of when wind speeds up as you walk between tall buildings in a city. Corridors may similarly funnel wind and carry seeds down them.”

But the big surprise was that plants with unassisted seeds also moved along the corridors. The prediction was that the corridors would have no effect at all on certain kinds of plants.

However, "we found a really strong response to corridors, contrary to what we expected," Damschen said. ""We think these plants must be being assisted in some way, and we think it's possibly from mammals. Unassisted plants exceeded our expectations by a long shot."

Their next theory is that mammals are inadvertently eating some of the seeds while foraging. To check this out students are now planting various kinds of mammal scat to see if they sprout.

(Do I dare suggest that higher education sometimes takes some strange turns?)

See the original news release fromWashington University in St. Louis


Doug Welker said...

We should all be aware that trail corridors are also dispersal routes for invasive plants. There are several ways that we can minimize this, such as
1. Avoid making trail corridors wider or more open than necessary. Most invasive exotics are sun-loving.
2. Install mounted boot brushes and signs, at least at popular trailheads and trailheads for trail segments where exotics are known to be spreading or where they might be likely to spread. Encourage hikers to brush mud off their shoes both after and before going on their hike.
3. Familiarize trail crews and hikers with invasive plants, and encourage them to remove them as they hike or work on the trail.

As for the signs and boot brushes, they might be good candidates for Challenge Cost Share or Mini-Grant funding.

Sharkbytes (TM) said...

These are really good points, Doug. Thanks for posting!