Miles O’Brien: Bio-geochemist Charley
Driscoll and forest ecologist Lindsey Rustad
are taking a little hike through
the woods--surveying their handiwork,
you might say.
Natural sound or music Miles O’Brien:
With support from the National Science Foundation,
they’re part of a team of researchers here at the Hubbard Brook
Experimental Forest in New Hampshire
that wants to know more about the impact of ice storms
on forests like this.
Easier said than done
since such storms are so hard to predict.
Charley Driscoll: Wow, Lindsey, look at that!
Miles O’Brien: So, they set out to make one.
Charley Driscoll: And, I don’t think it’s ever been done before.
Nat Sound of the sprayer
Charley Driscoll: How do we quantify the level of icing?
Really the accumulation of ice
is really critical in terms of the overall damage--we
wanted to be able to be very quantitative.
Lindsey Rustad: We had pumps down
in the Hubbard Brook
that pumped water from the brook through a series of hoses.
We had two of these vehicles going along
either side of our experimental plots,
spraying water 100 feet into the air --came down as a fine mist.
It was freezing conditions and it froze on contact.
Woman worker: They getting ice as well as the branches…
Miles O’Brien: They set up 10 plots,
each about the size of a basketball court.
Some got no ice.
Some got a quarter of an inch, which is pretty light.
Some half an inch--the equivalent of a major storm.
And some got three quarters of inch--considered “extreme.”
Now, they’re into a multi-year effort
to monitor how the forest is responding.
Charley Driscoll: So, what happens?
When we have an ice storm, it’s a catastrophic event.
It opens up the canopy.
There are some trees that are able to recover from this.
There are some trees that are not able to recover from this.
This is in an opportunity to the forest
to rebuild itself. Miles O’Brien:
On this day, they were measuring nutrient levels
in the water from the soil.
Lindsey Rustad: When you damage the canopy,
those trees are not taking up
as much nitrogen and carbon and calcium.
And, if they’re not taking it up out of the soil
that means it’s in the soil
and it can be leached into our streams and our lakes.
Miles O’Brien: They also gather up dead twigs
and branches that fall from the treetops,
carefully weighing how much detritus
is coming down from the damaged canopy.
And they measure the amount of carbon dioxide
and other greenhouse gases generated by soil microbes
and plants’ root systems
released from the forest floor.
Lindsey Rustad: So, if you have a catastrophic
disturbance like an ice storm
and you change the carbon cycling,
and if you tweak that soil respiration
even just a little bit
because it’s such a big number,
it can have a significant impact. Miles O’Brien:
The goal is to quantify
every bit of science data
they possibly can about how this ecosystem
is changing in the aftermath of the experiment
- the trees, the soil, the water,
even behavior of birds and insects.
Lindsey Rustad: So, we’re doing things like
measuring the temperature of the air,
the temperature of the soil, the moisture of the soil,
so a cascade of physical impacts. Miles O’Brien:
Driscoll says as our climate changes
we can expect more catastrophic weather events;
not just ice storms, but hurricanes,
floods and drought too.
Charley Driscoll: And as a society,
we’re going to have to deal with them
at all levels, at all types.
And so, I think the more we know about them,
we are better prepared to understand their effects,
to respond to them.
It’s going to be in our best interest in the future.
Miles O’Brien: Simulating an ice storm
to be better prepared
when the real thing strikes.
That’s way cool.
For Science Nation, I’m Miles O’Brien.