- I'm here today with Bob Popp,
who has served as Vermont state botanist
and is a member of the scientific advisory group
on flora of the Vermont Endangered Species Committee.
And today Bob will be presenting
Winners and Losers in a Changing Climate.
- Hi, everybody.
I'm just catching my breath here
cause I've spent the last half hour
trying to get into the Zoom meeting.
And as you see, I made it about two minutes ago.
So, yeah, happy to be here.
So just one quick disclaimer that I put this together
sort of as a project for the flora advisory group
of the Endangered Species Committee.
And I just want to say the work is entirely mine.
I mean, I presented it to them,
but they didn't vet it in any way.
If they had, it would probably be more accurate,
but it would have taken more time.
So, that being said, what I've done here,
and I'll get into this in a second,
is somewhat subjective in that, in this exercise,
I looked at the 162 plants that are listed in the state.
And, don't worry, I'm not gonna go through all of them.
I just wanted to show a small subset of them.
And I tried to categorize them into their distribution
being endemic, peripheral, or central.
And then there's a few that are actually disjunct as well.
And, again, this is fairly subjective.
I mean, what I did was I viewed range maps
and some of the manuals and just,
you know, my own knowledge, et cetera.
But some of these that are in one category
could probably be put in another category.
So, it's, yeah, it's a point in time
and it's the best effort.
I also took a subset of the plants
and tried to assign them to a different forested category.
And that too is pretty subjective.
So, just, without any further ado.
The one thing I wanna point out here is
this may not be the best example,
but you'll notice the global status,
most of the plants on the Vermont T and E list
are gonna be G4 and G5.
And you see that here.
There's a few G2s and G3s and they're pretty unusual.
And the point being that Vermont doesn't have
a lot of globally rare plants, unfortunately.
We're not the tropics,
we've been glaciated up till 10,000 years ago.
So there hasn't been a huge amount of time
for evolution to occur.
But be that as it may, we do have 162 plants
that are endangered or threatened here.
So, reiterating what I said before, we have the 162.
Only two of those species are G1 or T1.
And for those of you that aren't familiar
with the vernacular, G1 is like the most rare.
It's globally rare.
It means it's rare throughout its range.
Going through G5, which means it's pretty common.
T just is the exact same thing, only it's a sub taxa.
So instead of being a species,
it would apply to a sub species or variety, what have you.
So we just have two that are either G1 or T1,
and they're both, as you might expect,
they're both endemics.
And if you look down at the bottom,
one of them is, the G1 is the Isoetes viridimontana,
which is a newly described species in Vermont.
It's the Green Mountain quillwort.
And then the Jesup's milk-vetch is the T1
because that's actually a variety
of the nominant, Astralagus robbinsii.
So then moving onto G2,
you'll see we have four species, and the peripherals,
there's actually one plant in there that's a peripheral.
The other three are either endemics or disjuncts.
So that's the Champlain beachgrass
and the Boott's rattlesnake-root, are the two endemics.
And then the disjunct is the serpentine sandwort,
which occurs here,
and then it bounces up into Quebec and Labrador,
so it's pretty separated
and restricted to the serpentine belt.
And then moving on to G3, which is globally uncommon,
you see the number of species keeps getting higher.
We move to six and then to 31 and then to 119.
So, again, of the four species, we have one endemic
and one that's in its central part of its range.
The endemic is the last one here,
the Green Mountain maidenhair fern,
and the central one is Polemonium vanbruntiae,
the, spacing out here, eastern Jacob's ladder.
And then as we get into G4,
the less globally rare ones,
you see 77% of those are peripheral and seven are central.
And then in the G5s, 84% of them are on the periphery.
And we just have two disjuncts and then a few centrals.
The two disjuncts that are G5s
are the beach heather and the beach pea,
both of which are ubiquitous along the coast,
as you probably know.
So, getting back to the main event here,
the main analysis I did,
of T and E plants for the distribution status,
you'll see of the 162,
only 3% of them, or five species, are endemics,
and we've already mentioned those.
Three species or 2% of them are disjuncts.
And then there's about 15% that are central.
By that, I mean, they're kind of
in the middle of their range.
The vast majority of our T and E plants,
approximately 80%, are on the periphery.
And what I did was I combined
those that are on the north edge of the periphery
and those that are on the south.
So about 42% of them are on the northern edge of their range
and 32%, so slightly less,
are on the southern edge of their range.
And then there's a few, a little over 5%,
that are on the eastern edge of their range.
And those are essentially prairie species
that just barely get into New England,
but they're more ubiquitous.
They're pretty much all G5s, so ubiquitous in the Midwest.
So then, this being the forest ecologicals monitoring co-op,
I had to do something with forested habitat.
So of the 162, I refined it down to about 44 species
where their habitat is primarily forested.
Now some of these, some of these could go either way,
they occur in forest and open.
And so again, it became somewhat subjective,
but these are the ones where I thought the primary habitat
was some sort of forested natural community.
And within that, I tried to actually assign them
to one of the natural communities
in the "Wetland, Woodland, Wildland" book.
And so what you see here is, of the forested species,
again, almost two-thirds of them are on the periphery
at the northern edge of their range.
And about 20% are in the periphery
in the southern edge of their range.
Whoops.
But what jumps out to me is the communities they're in.
So I think that the one that's most represented
is mesic maple-ash-hickory-oak forest,
and then dry oak-hickory hophornbeam forest.
And both of those communities are expected
to do well with climate change.
I mean, they're both more adapted
to warmer dryer conditions,
and you notice the plants that are associated with those,
as you would expect,
are on the northern edge of their range.
So they should fare pretty well.
But if you look at the plants
at the southern edge of their range,
a number of those are in cedar swamps.
That's like the next highest category.
And from my understanding, what I've read, is that cedar,
along with most of the spruces and balsam fir,
are expected to decline,
at least under the high emissions scenario.
So that doesn't bode well for the future of our cedar swamps
and those plants that are pretty much,
I mean, associated very strongly with cedar swamps.
And then there's a few other plants in other categories.
But I think those are the things that really jump out,
the oak forest, the hophornbeam, again,
all going to do fairly well.
So, moving on to a few case studies here,
this is studied, done by Jerry Jenkins,
where he's been monitoring our only population
of Anemone multifida, the early thimbleweed.
And actually, I think this was most recently picked up,
this monitoring, by Matt Peters, who may be in the audience.
I can't see everybody out there, so...
But, Jerry Jenkins has been monitoring this plant
since, oh, for about, I think, 20 years or more, I'd think.
Yeah, 1988 to 2010, he did it.
And what he found was...
Well, first of all, let me back up.
This is a plant that is on the periphery of its range,
the extreme southern edge of it.
So, in New York State, it is considered to be extirpated.
They had one population
and it hasn't been seen in a number of years
and they've gone back to the site,
so it's assumed to be completely gone.,
In Maine, they have eight populations,
so that would make it S2.
And then up in Canada, it gets more abundant.
So this is a G5 species because it's so common
up in Canada and Ontario.
I've been told it grows in roadside ditches
up in northern Ontario.
I'd love to see that, or maybe I don't.
So anyway, what Jerry found was,
monitoring this for over 20 years,
the plants have declined 77% over that period of time.
And what he's finding is that there's obviously
an excess of mortality over recruitment,
but it's driven primarily
by high temperatures and dry summers.
And as you can see in the top graph here,
the one in the upper right,
it's almost a series of tabletops in a way
in that you have some really bad years
where there's a very high mortality rate drop-off
and then it levels off for a little bit
where there's reasonable years,
but it still can't recover the loss.
It just kind of holds its own.
And then there's another steep decline,
another steep decline followed
by a level off period, a decline.
And all those years where there have been
really, really steep declines have been
unusually hot and dry summers.
So that's clearly, I mean, it seems like a smoking gun,
what's kind of pushing it over the edge.
It's at the edge of its climatic range to be sure.
And in some of the bad years
there's been up to a 30% mortality.
And then again, the recruitment just is enough
to hold even for a few years,
but it doesn't ever really increase it.
I mean, you see here in the early nineties,
there was actually a slight increase.
And then maybe again in the late nineties
there was a slight increase,
but recruitment is just not doing it.
So this is, needless to say, this is the bad news.
This is Jerry's projection of what's to come.
And we're at about right here now.
We're down to about 100 individuals,
and you see he predicts total extirpation
of this population by 2030, more or less.
And, yeah, we're just kind of monitoring the decline.
I mean, we don't know what else can be done.
We've actually tried planting seeds in cracks in the rocks
to get them started, but it's just...
Maybe it's a losing proposition, I don't know,
but that's beyond the scope of this talk,
something to be discussed over a beer, perhaps,
which we can't really do too well virtually.
So the second scenario, or case study,
is a more positive one.
And this is spotted wintergreen,
which is on the northern periphery of its range.
And you see in New York it's S4, which is really common.
Massachusetts it's S5.
And then as we go north, Maine it's S2, so it's quite rare.
Ontario, it's quite rare.
I don't believe occurs in Quebec, which seems a bit odd.
But you see what's been happening.
In 2006 we had it ranked as S2,
and we knew of 11 populations.
And then in 2018 we changed it to S3
cause we had 24 populations.
And now, I think, in our biotics database
we have something like 37 populations,
and it's still restricted to three counties,
Windham, Windsor, and Rutland.
But recently new populations have been found
in Pomfret and Springfield, which is, you know,
getting to the northern edge of Windsor County.
So this is a plant that really seems to be moving northward
as the climate gets progressively warmer.
And actually, this was a little unfair
because this just made a really great case study,
but it's not state listed, it's just rare.
So, anyway, I kind of bent the rules a little bit
to talk about this one.
But if this were, it would, you know, on the list,
it would have been...
its primary habitat would be forested settings.
And those would be, if I had to put it in a community,
it would be oak-pine, oak-pine-dominated communities,
which, again, we expect
to do really well with climate change.
And this plan certainly, you know, lends to that.
I should also mention that in Art Gilman's "Flora",
which came out in 2015,
so he probably based it on like 2012, 2013 records,
he had it listed as rare.
So this is something that we've only been aware of,
like in the last five or six years,
how much the spotted wintergreen is increasing.
So, again, this will be, this would be one of the winners.
And unfortunately the anemone would be
most likely one of the losers in the climate game.
To sum up here, the majority of Vermont's listed plants
are on the periphery of their range,
about 80%, as I mentioned.
And typically these have lower global ranks,
that is, they're G4s or G%s,
so they're more common elsewhere.
They just barely get into Vermont.
Slightly more of the plants are on their northern periphery,
42 versus 31%.
And, you know, with other things,
not considering other factors,
this bodes well for those, for that 42%,
because they're likely to increase.
Even if they move northward,
they've got the whole state to populate,
cause a lot of them just occur
in the southern-most counties.
The ones on the southern periphery, however,
would be expected to decline
or their range in Vermont to contract,
and they might move northward if that's a possibility.
Just as an aside, the photo is
the Green Mountain maidenhair fern,
which is probably one of the poster children
for the Vermont flora, because it was a species of fern
that was first described in Vermont,
actually by Cathy Paris from UVM.
So, that's pretty neat.
I always take the opportunity to show that off.
So, lastly, just some assumptions here,
and I kind of agonized over this,
that the changing climate conditions,
I mean, they could favor
more rural disturbance adapted species
that are gonna respond more quickly to the climate changes.
So, you know, things that are shorter live annuals,
lighter seeds, disperse more readily,
are gonna move more quickly, so they might do well.
But I'm also thinking that the real stress toleraters
might persist in climate refugia and just kind of hang on.
So, it could work both ways, depending, you know,
where you're situated,
what kind of habitat you're associated with.
Again, that's a bit of an oversimplification
because survival is gonna depend
on so many different factors.
The phonology of the plant,
whether it needs a freezing period, the seeds,
and whether that'll be met.
Its phonology, whether it'll have time
to flower and set seed,
whether it will be at a sink with pollinators,
its competitive capability,
because we expect a lot more other species
to start showing up, especially non-native things.
Continued persistence of the habitat.
I mean, if you're in a cedar swamp
and all the cedars don't persist,
that kind of changes things quite a bit, I would think.
You're gonna see black ash cedar swamp and all the ash die
because of emerald ash borer,
although that's not necessarily a climate thing, but...
So, I guess, to kind of speculate a little bit
about the best use of our resources,
clearly we're not gonna be able
to protect every one of these species.
We just don't have the resources
or the person power to do that.
So, my thought at least is
to protect the habitat as best we can,
especially like refugia
where rare plants might be expected to persist
with landscape connectivity.
Things have to have some ability to move.
Plants obviously aren't as mobile as animals,
but we still need, you know,
pollinators to move back and forth.
A lot of plants, the seeds are moved by animals,
so there is a connection there.
I would think our focus would be
on the globally ranked species, the G1s, the G2s, the G3s,
or the ones that are disjunct in Vermont.
Again, disjunct species often have very unique genotypes
and we should definitely try to protect those.
And then lastly, going a little bit out on a limb here,
one thing to consider is assisted migration.
And I don't think we should be moving things
willy-nilly over the landscape,
but I think we should certainly consider it
for G1, G2, and disjunct species
that might need some help moving north.
I mean, if their habitat no longer exists in Vermont,
I think one alternative is extinction.
The other alternative is to help them migrate.
And I know that's gardening, or maybe even playing God,
but we kind of boxed ourself into this one.
And it's something I'm trying to get people
to consider more and more or at least talk about,
the benefits and liabilities of assisted migration.
And then that's pretty much it,
except in the background here
is another one of our poster children.
This is the Jesup's milk-vetch,
which is the G1, I mean G5, excuse me, T1.
So it's an extremely rare subspecies
of more common milk-vetch,
and it occurs in only three places,
it's worldwide distribution, along the Connecticut River.
We're working to actually introduce it
to some new sites to the north.
So, maybe we're already doing assisted migration.
I don't know if we would call it that, but we might.
That's all I have to say, and I'm happy to answer questions
or have a discussion as time permits.
So I'll turn it over to Matthias, and let him moderate.
- Thank you, Bob. That was great.
I really appreciate it.
- You're welcome.