viernes, 6 de febrero de 2015

Students Kill Invasive 'Phrag'

An invasive species of marsh reed has taken over a wetland in New York, and high school students have joined with biologists to try to destroy it without using chemicals.

Self-study activity:
Watch this National Geographic video and say whether the statements below are true or false.



1 150 years ago the phragmites were already in the marsh.
2 100 years ago the phragmites covered 90% of the marsh.
3 Phrag is a native plant in the marsh.
4 Phrag doesn't smell good.
5 There has been a great loss of birds as a result of the superabundance of phrag.
6 There is widespread agreement on how to deal with phrag.
7 Phrag is essentially a damaging species of plant.
8 It will take a very long time to find a solution to the problem of phrag.

This marsh, if you were here 150 years ago, it was like a patchwork of all different kinds of micro-environments and you had sedges and a few bushes and some phragmites and some spartina, just really, a dozen different major species.
And in the last hundred years, it's become essentially a monoculture. Over 90% of the surface is covered by one plant, the species called Phragmites australis, which is simply common reed.
For some reason, this Northern European subspecies that came into Connecticut about 200 years ago has just taken off up and down the East Coast, from Maine to Florida.
Phragmites can hold the waste and stuff, but, too much of it, is not needed. Especially where you have other native plants that are trying to grow. And, the smell too, it's like, horrible.
The central issue with this invasive is that it disrupts the balance that is at the heart of the existing food chain. And, can often lead to a tremendous loss in biodiversity.
What got me involved in the marsh, was working with these kids. But what came out of that was a ten year ecological study of the marsh that is really unique in terms of how much real data it’s produced, and we've had some discoveries about the extent to which the marsh has become a monoculture agriculturally and the extent to which we've really seen a loss in diversity in the fish species as a result.
There's been a big controversy in the last year plus, in Piermont, about whether to try to remediate this invasive plant, and if so, how. The cost effective solution is to spray with a chemical. A lot of people are opposed. So, this summer is trying to look at non-chemical ways to help to manage the phragmites invasion.
So the idea that we're working on is if you roll black plastic out, over this thing, we think we can get the sub-surface hot enough to actually kill the phrag roots by heat.
The way we started doing our experiment was we collected rhizome samples from different plots that we have. We brought them back to the lab to boil them at different temperatures. And they stayed there for 24 hours, just to determine how we can cook the rhizome, which is the root, to kill off phrag.
We replanted them again, today, to figure out how do they grow. But most of them are pretty dead by now, so I doubt they'll grow.
This plant is not a monster. This plant's not an evil thing. It's a very productive plant; it provides some important ecosystem services. It is sequestering carbon. It is holding the marsh together. It is keeping up with sea level rise. It is providing a home for muskrats, but you have to, at the same time, have a perspective on what's been lost.
This is not something you're going to fix in a year or ten. It's all up and down the coast. It is going to reinvade a number of times and unless you create the human infrastructure required for that kind of long-term management, then you really haven't done much.

Key:
1T 2F 3F 4T 5F 6F 7F 8T