Alright, so continuing, as I highlighted
as Tony talked about NSRC largely
supports graduate students work.
Another important part of this is supporting
sophomore faculty and allowing them the
I often view NSRC funding as seed funder
that can be leveraged through other federal initiatives
that think that we'll talk about a little bit.
Manage from the University of New Hampshire, longtime
resident in New England, a local expert,
a forest ecologist, broad interest
and I think you'll touch on at least one
as well as three projects center city projects.
So thank you Matt.
[Matt] No thank you.
Great, So yeah, I'm going to try in this time
to talk about three projects
that we have going in my research group that are all funded
by NSRC and they all happen to be focused
in various ways on seedlings.
I co-managed the eco hydrology group at UNH
with Professor Heidi Asbjornsen and we have seven
Grad students in our group right now.
And the work that I'll be presenting represents
primary work of four of those students.
So the three projects we'll be talking about are,
one is an assisted migration project.
So looking at different tree species, how they might do as
planting stock or northern forest,
particularly in a future warmer climate with more drought.
Also we talking about
and that's the one that's stuck furthest along.
So we'll spend the most time
'cause there's more results from it.
We have two other projects that started more recently.
There's an oak regeneration project
in the White Mountain National Forest looking at the role
of prescribed fire in improving oak regeneration success.
And finally, one of those
indigenous forests knowledge fund projects
that heard about it as a new parameter of funding.
And that's working with the no vegan Abenaki
and looking at Atlantic White Cedar regeneration,
which is a cultural important species.
So I'll start by talking about our project on
assisted migration and I'll highlight particularly the work
of Sam Zuckerman, the PhD student
who's conceived the project
Forest Service collaborators
Tony and Jay Wason at Maine.
So Tony did a really good job of introducing the idea
of forestry assisted migration.
Planting is not something we think of as a major part
of forest management in the northeast,
but people are really interested in it
and particularly how do we make a species mix
that is functionally diverse
and ready for what that future climate looks like
or the range of possibilities
of the future climate might included.
So the research questions here are the seedling ecotypes
of the source population that we bring seedlings.
Does that influence seedling success when grown in a common
garden in a greenhouse in Durham, New Hampshire?
And then how do these species
and ecotypes that we're studying respond
to a drought treatment?
These are seedlings largely from
the New Hampshire Forest nursery.
We comp, we studied seven species.
Again, some of those were kind of on the list of
commonly available and interested planting species
focused on New Hampshire ecotypes.
And then we supplemented with seedlings
from a Michigan nursery.
So a similar temperature
but a drier climate than what we have,
as well as from Virginia similar precipitation,
but a warmer climate than we have in New Hampshire.
This was all set up in 2022.
Midway through the summer,
half the seedlings received a drought.
We brought them down to about 5% water content in
the pot for three weeks.
We repeated that in 2023,
except the drought treatment was divided
into two treatments, one of which was just repeating
that moderate drought and the other was an extreme drought
of really just washing the physiology of the trees rundown.
How they dealt with stress until they completely died?
Here's what things look like about halfway through 2022.
Open-ended greenhouse in Durham.
Seedlings arranged in blocks.
Blocks randomly assigned draft treatments.
We collected a ton of physiological data from these,
especially in 2023.
Some of these measurements are kind of destructive,
so we didn't want to do,
we don't wanna collect too many leaves when the trees were
still really small in 22.
But this was really we'd a big team.
We had three full-time undergrads all summer
plus Sam, and we're still processing samples
for the trades and anatomy as well.
I'm gonna focus on just two results to model conductance
and heightened diameter growth for now.
So we saw across these are five of the species,
this is 2023.
We saw some kind a range of differences
in general droughted plants grew less.
Differences were not always significant.
What's graphed on the Y axis here is a growth rate.
So you can see black cherry, not surprisingly,
was growing at more than twice the rate
of some of the other species.
Also, interesting to note that when things got limited,
when water was limited, trees really
responded more in diameter growth
than they did in height growth.
So they're prioritizing hyper of this stage of their life,
presumably to compete for light
over diameter growth or biomass.
We also looked at stomatal conductance in a lot of detail.
So stomatal conductance is a measure of
gas exchange at the leaf surface.
And when water becomes limiting,
plants can reduce the conductance
of the pores on the leaf surface to conserve water
that comes at a cost because it also reduces
the amount of carbon uptake that can occur
and carbon uptake for photosynthesis.
So the first part of the summer June July,
we saw basically no carryover effects
between the blue controlled seedlings
and the red lines which represent the ones
that had been previously droughted.
July 10th, we started the drought.
We withheld water from the ones in those treatments
represented by those red lines
and we can see stomatal conductance declines
kind of at a different rate for each species.
So the cherry declined pretty much immediately.
Oaks took a little bit longer.
Sugar maple went more than a week without seeming to notice
that we hadn't watered them.
August 3rd, we began to re-water the ones in this
bright red treatment, the moderate drought.
And we see recovery also varies a lot by species.
The cherry very responsive,
bounces back almost immediately when they get re-watered.
Oak is a little bit slower, doesn't come back quite
to the control level by the end of the summer.
And sugar maple once again, didn't notice
that they had been watered again.
They still, there's some sort of damage or you know
loss of function in those leaves that even that drought,
they didn't really recover for the rest of that year.
So here's what things look like in the greenhouse.
This is the first week of the drought.
Nothing is too obviously wilting yet.
Another week in, we can see the cherries
that were in the extreme treatment
lost temperature pressure.
The leaves are just all floppy dangling on the branches.
Pines of oil starting to look pretty sad.
And then a few weeks later we start
re-watering the moderate drought treatment.
But the cherries that didn't get re watered
are basically completely dead at this point.
So preliminary findings, and again
we have a lot more data coming in.
This is just what we've been able to work with so far.
All species reduce water use during the treatment.
Recovery varied by species growth effects.
Also varied by species if there's a theme.
Sugar maple is the one that seems
to not really know what it's doing when it hits drought,
it just, it doesn't respond in the way
that the other species do.
Cherry grew by far the fastest,
which meant it had the highest water demand
and was affected very quickly
when it started encountering dry soils.
Within species, there were really not any differences
by ecotype, but Virginia versus Michigan
versus New Hampshire resource populations.
Again, we're looking at a lot of other parameters
and we expect to see some differences there.
But it didn't translate to growth
or gas exchange differences.
Not something we were planning to measure,
but we noticed there was very high winter mortality
in some of the southern species, Southern red oak,
black walnut.
Too many of them died in an unbalanced way
that we couldn't carry them forward in the experiment.
Sugar maple also saw really high winter mortality in a way
that was more balanced than we were able
to carry them into 2023.
I think this has to do
with snow pack in Seacoast New Hampshire.
There was no snow on the ground at all
during the coldest part of the winter last year.
And so we packed them all together.
Stuffed hay in between them.
But these one gallon pots froze completely solid
at some point and I think the sugar maple seedlings
really don't do well with that situation.
So moving on quickly, another project
that's just getting started is looking at
oak regeneration in burned and unburned stands
in the White Mountain National Forest.
And the idea here again is thinking about range expansion
kind of near the northern commercial range limit of
Northern Red Oak.
And there's some interest in whether fire is something
that can help improve regeneration
outcomes in that environment.
And I'll acknowledge Nat Cleavitt at my collaborator
at Cornell, who's was kind of the first one
to have this idea that we should study this.
There are few different project components here.
So we're looking at oak regeneration in prescribed burns
and paired control stands
in the White Mountain National Forest.
And we also conducted another potted seedling study
with acorns from burn versus unburnt soil.
There's also a tree-ring component to this,
but I don't have any results to show you from that yet.
Here are the study sites
in the White Mountain National Forest.
The core of the study is these shelter woods
that were cut in 2015 and then burned in either 17 or 18.
These were spring burns.
There're also some clear cuts, small patch cuts at the
Bartlett Experimental Forest
which were burned in spring 21.
And then opportunistically right around the time
we found out that we had funding.
There was a wildfire in Crawford, not state park.
And we decided like, oh well let's add that
to the experiment as well.
It's obviously not an appropriate stand,
but it's an oak beef stand
and the mortality varied from 30 to 80%
depending where you are in there.
So things got opened up, it's kind of the natural version
of a shelter would burn except it was much more severe
than any of the prescribed burns.
So the soil mediated effects might be much stronger.
A lot of data, Khan,
the grad student is still working this up.
I'm going to talk just about the oak seedling density data.
There's a highly significant effect
of the burning treatment on the oak density.
So this is seedling size class.
We're calling it everything for the DBH less than one inch.
And yeah, we see a lot more seedlings
in the burned managed stance
and in the unburned paired stance.
The all these seedlings are aged,
they're scored for obituary
and measured for height and diameter
and we need to divide up that analysis.
We need to stratify it by age before it can move forward.
We've got some interesting results from
the potted seedling study.
These are all local acorns,
which were not easy to collect in 22.
And we see that actually the burned
unsterilized soil seemed to give a boost to those acorns
in the early stages, which is not what we hypothesized.
We thought that the effective fire might be to reduce
pathogen loading in the soil.
And so we thought the sterilized unburned soil
and all the burned soil might do better
than the unsterilized unburned soil.
But this, there's something more complex going,
but the interaction with steril is sterilizing the soil
indicates it's probably a microbial community effect.
So we're really interested in what's going on there.
And finally, I just wanna mention this one
is the least far along, but also the most unique product.
We have study of Atlantic White Cedar regeneration
at Bradford bug in partnership with
the Nulhegan Abenaki Nation.
We'll be assessing natural regeneration
of Atlantic White Cedar establishing monitoring plots
and documenting the cultural value towards creating
an eco-cultural stewardship plan
for the species on that landscape.
It was a very difficult summer
to do field work in a swamp this past year.
So we don't have a lot of soil data.
We have transects set up that vary in basal area
of mature trees, but there's a lot of differences.
Only some of them have any seedlings
at all anywhere in site.
So there are really important differences across this
complex hydrologically land use history complex landscape.
And we're trying to figure out what those are
in order to make better recommendations for how to manage it
to continue regenerating this culturally important species.
And with that, I'll thank the funding
and many partners and assistance.
Perfect, here for one deal.
Nice job. Now any questions for now?
[Audience] The assumption behind assisted migration
which is common assisted gene part,
I guess that I'm talking about moving a
species place to another is
that the ecotypes differ from one another.
I think we're finding similar results in some of our work
that maybe ecotypes don't differ from one another.
Makes that, you know, strategy just risky
and not really maybe that effective.
So I'm curious why you think your ecotypes don't differ
and what does that mean for
the effectiveness of assisted gene?
[Matt] Yeah, I mean we're still working on that.
I mean obviously they different in some
measurable ways, right?
They have different frequencies of certain genes.
You know, there are traits that you can measure
that are different out there in the wild populations
when you pull them into a common garden.
It's a different environment. Yeah.
So we're, there are hints at differences,
but we gotta be careful about what statistically significant
and that the difficult winter that we had makes
that harder than it we're hoping it would be.
But we're still making progress on that.
[Audience] Yeah. Just to follow up on that question,
one of the suites of traits that ecotypes
tend to be the most genetically differentiated
or phonology, particularly timing, you know,
entry and exit of dormancy.
[Matt] Yes.
[Audience] So was that something that
you were either measuring directly
or maybe indirectly through like final head growth end
of season when they're setting bud and arresting?
[Matt] Yeah, there are observations on that.
They weren't as frequent as I hoped that they would be.
It wasn't strong, which surprised me actually.
[Audience] Thanks so much for your great work.
So the first study involving the pots,
I was just curious if you have plans to do field trials?
'cause as you know, micro networks are a huge part
of the hydrology and plants
and their potential adaptation to less water.
[Matt] Yeah. Potted studies are definitely limited.
I mean, the other thing that's different
is each plant has its own equal amount of soil
and there's no competition between seedlings
or with seedlings from church trees or herbaceous species.
[Audience] Was this one from the forest?
[Matt] No, it was a greenhouse, it was a soils mix.
These were all bare root seedlings.
So they came with their own micro rising.
[Audience] Right.
[Matt] But it's, yeah, it's not a field soil.
[Audience] You gonna do field trials in the future?
[Matt] That's one direction to go.
-[Audience] That'd be good. -[Matt] Yeah.
There's, this was in part inspired by the larger
adapted soil culture experiment that's been planted
all over that Tony's involved in.
And we're originally hoping to do experiments
droughting those seedlings.
And after some trials we didn't think
we could do it well enough to trust the results.
So we moved everything into the greenhouse.
[Audience] Yes. I guess my question,
which I didn't articulate clearly is, do you have a idea
or guess of what percentage of the hydrology
of the plants would be connected to those networks versus
what you can determine in the box?
[Matt] It's going to vary tremendously by
species federal ship.
[Audience] Yeah.
[Matt] Yeah. The speeds that rely heavily,
the tech to mycorrhizal fungi are gonna reach a lot farther
and deeper than the vascular ones.
Yeah.