Michigan Old Growth and Invasives  


== 2 of 3 ==
Date: Mon, Nov 19 2007 12:30 pm
From: "Daniel McConnell"

Thanks for the warm welcome everyone. Brian, unfortunately I am quite
unfamiliar with old growth in the eastern UP (east of Munising). I did visit
Tahquamenon Falls State Park years back, but didn't have the time to explore
the older forests. If you were to make it to Marquette, however, I could
certainly point you in the right direction. I know of some excellent white
pine-hemlock tracts, as well as what I believe is at least 30 acres of
virgin white pine north of town. With my admittedly crude measurement
practices, I found many white pine at least 110 feet tall, and a couple I
suspect may be 120. Dukes Experimental Forest, about 20 miles southeast of
Marquette, contains pretty massive sugar maple, among the best I have seen.
Logging will occur soon, so seeing the forest before this occurs would be a
worthwhile trip in my opinion. There is a RNA (research natural area) within
the forest that is not in immediate danger of future logging operations.

This ties in with your question about my invasives surveys in old growth. I
surveyed all of Dukes this summer mostly for invasives. What I found was
burdock- abundant at times, reed canary grass- abundant along many roads,
and marsh thistle... along with a few others. I scraped the stands
especially thoroughly for garlic mustard. Thank god none was found! It would
simply demolish biodiversity (and tree regen) in this ideal rich mesic
habitat. I have found several invasions of garlic mustard in old growth
sugar maple near Au Train Falls and have seen first hand the damage to the
understory plant diversity and maple regeneration (major invasion is 70+
acres consistent coverage under dense shade). These invasions are rapidly
spreading and matching the severity I have seen in the lower peninsula
populations. Now is certainly the time to act if we want to get a hold on
garlic mustard in the UP... I think all it would take is a field trip to
some southern sites to convince officials of the damage the plant can
inflict on our forests. In Dukes the invasives were mostly along roads
(though some of the densest populations were in roadbeds that have been
closed off and out of operation for 30+ years). After the logging operations
I will be very interested to see what invades the stands... one could say it
would make a good masters project!

My surveying has taken place in the western Hiawatha NF, so for much of the
rest of the UP I can only speak for what I've seen at 55mph (or from what
I've noticed while searching for other things). I haven't found much glossy
nor common buckthorn, fortunately, in the western hiawatha. As far as
invasives in other parts of the UP, many species such as spotted knapweed,
smooth brome, reed canary grass, and st. john's wort are solidly
established, as well as some dense non-native honeysuckle populations and
buckthorn in places. Common tansy and houndstongue are more of an emerging
threat in the hiawatha. Well, I could go on about this. The situation isn't
as bad as elsewhere, true, but if we want to gain an honest foothold on
invasive situation, this is the stage in which to concentrate the effort.

== 3 of 3 ==
Date: Mon, Nov 19 2007 6:01 pm
From: Brian Miller

Interesting to hear about invasive species of the UP. I completely
agree that now is the time to act given that they are not yet out of
control. I wonder what can be done about garlic mustard, however? It
seems almost unstoppable in some areas where there is bare soil.
That's too bad to hear about the logging in the Dukes, as I am
particularly fond of large, old sugar maples. How soon will this occur
because I don't think I can make it there this during this trip, but I
may return sometime next summer to finally make it out to the
Porcupine Mountains and Isle Royale.

From what I have seen in southern Ontario, the result of selective
logging on the forest ground layer often results in a marked increase
in invasive species (particularly garlic mustard, Geranium
robertianum, Arctium minus). My assumption is that is due to skidders
carrying weed seeds into the forest from roadsides (as you mentioned)
and from forest edges where the weeds can then thrive in new canopy
openings. Another major reason that I think has to due with skidders
that are not properly cleaned between job sites. I have seen some
clear examples of this involving the awful dog-strangling vine.

If the directions to the Duke Experimental Forest are simple enough,
it would be great if you could provide them just incase I do end up
having time to visit this forest.

I'll be leaving later tomorrow, so I better go get ready. This is
going to be an old growth forest filled trip!


== 1 of 4 ==
Date: Tues, Nov 20 2007 5:29 am
From: Russ Richardson


Invasive species are my nemesis and they are rapidly impacting more woodland
than they are not impacting.

The hygiene of logging equipment is a major way in which invasive species
are brought into the woods but with modern environmental laws there are
increasing requirements that any sort of ground disturbance be followed by the
application of vast amounts of mulch hay. Because there are no standards for
mulch hay in most places....Michigan has started the first "weed and invasive
seed free" mulch hay pilot program in the central part of the US but the science
is wide open and most people in the business of manufactuing stumps have
little concern for the infestations of botanical AIDS they are spreading across
the countryside.

Russ Richardson

== 2 of 4 ==
Date: Tues, Nov 20 2007 6:06 am
From: "Lee E. Frelich"

Dan, Brian:

A lot of sugar maple forests in the Midwest have what I call Forest Decline
Syndrome, initiated by European earthworm invasion, followed by invasive
plant species if seeds are present (garlic mustard, etc., which depends on
earthworms presence to invade), and severe deer grazing of regeneration,
and in recent years, persistent and repeated droughts. The only forests
immune from this are the ones within heavy lake-effect snowfall areas,
where water is recharged by snowmelt each spring, especially if on silty
soils. Some such areas, such as in the central parts of the Porkies are not
yet invaded by earthworms and deer leave the area during winter because of
the snow depth. A few stands on very silty soils in the snow belt have even
managed to make the transition and survive earthworm invasion, remaining
lush and productive, while other stands have been devastated by the
earthworm/deer and drought combination. Sylvania Wilderness is a good
example of devastation--it has high deer numbers, sandy soils, and
earthworms are invading fast, and we have not had any significant tree
recruitment on our permanent plots for the last 20 years. A few small
patches still the lushness that was present 20 years ago before the decline
began. Also present in most areas are European slugs that eat native tree
and herb seedlings when they germinate. We aren't sure exactly how
important their role is, but one of my graduate students is interested in
them and may collect some data next summer.

Isle Royale still has some earthworm free sugar maple forests at higher
elevations near the west end of the island, but the rest of the island is
more boreal in nature and is turning into a spruce/moose savanna due to the
high moose numbers there that prevent reproduction of trees except for
spruce. The moose numbers have begun to crash in recent years, and maybe
that situation will reverse.


== 3 of 4 ==
Date: Tues, Nov 20 2007 7:03 am
From: "William Morse"


Interesting what you said about the immunity of areas receiving heavy
lake-effect snowfall. Here in western New York we get a bit of lake
effect and as part of the larger picture of the Great Lakes region we
get our fair share of snow; however, there is no shortage of concerns
when it comes to invasive species. I heard or read somewhere that
non-native species are arriving to the U.S. at a rate of one new
species every eight months. If anyone has a reference for a similar
figure, please pass it along.

Despite the largest public focus being on aquatic resources, a real
threat exists to our terrestrial resources. There is an ongoing marked
change in the forest structure of western New York. The primary factor
contributing to the compositional change of the forested landscape is
the invasions of exotic species. I've heard/read that the likelihood
of invasion is exacerbated by the frequency, intensity, and timing of
storm events (ice storms and lake-effect snow) and insect outbreaks
that make our forest more prone to such invasions. Still, the greater
threat is posed by the "human factor". We provide the best and most
efficient distribution of invasive species and we also provide the
disturbance preferred for rapid colonization.

Many of the invasive plants that are most harmful to the native
biodiversity have been hand-planted as part of conservation seed mixes
and packages (multiflora rose, tartarian honeysuckle, European
buckthorn, and non-native barberries) without the knowledge of their
invasive nature. For awhile, a few state agencies were endorsing the
use of purple loosestrife to control erosion! I seem to remember
hearing that kudzu was introduced for the same purpose. To date NRCS
offices routinely sell/distribute "conservation mixes" containing
non-native species that have the potential of becoming invasive.

As you know, these species are generally shade tolerant and quickly
dominate the forest understory, preventing or suppressing the
recruitment of native tree species. In some forests, these shrubs are
preventing smaller plants, including tree seedlings, from developing.
There are few native saplings that are able to reach past the shade of
the invasive shrubs to become mature canopy trees. These areas appear
to stay in the seral shrub field stage much longer than similar
successional communities dominated by native shrubs. In every sense,
it looks like arrested development. Maybe this is due to competition
but invasive plant species can significantly change the
characteristics of ecological community nutrient cycling, soil pH,
etc., often so much so that natives can barely survive in the area, if
at all.

Along with the risk of being overrun by non-native trees and shrubs,
our forests are at risk of being completely transformed by such
vectors as sudden oak death, white pine blister rust, beech bark
disease, butternut canker, Annosum root rot, emerald ash borers, wooly
adelgids, beech blight aphids, and Asian long-horned beetles. Such
species as Canadian hemlock, white pine, spruce and fir trees are
currently being impacted and in nearby areas American beech, butternut
hickories, oaks, and ash trees are being threatened and decimated by
invasive species.

So for all of my rant, I'm left with Mark Twain's famous quote, ""If
you don't like the weather in Buffalo, wait five minutes." The idea
transcends to the turnover we are seeing in species along with the
dwindling diversity we are finding. The times, they are a changing.

Travis Morse

== 4 of 4 ==
Date: Tues, Nov 20 2007 7:35 am
From: "Lee E. Frelich"


The heavy lake effect snowfall allows some resistance in the Midwest
because it alleviates impacts of drought (by recharging the subsoil
moisture each spring) that are more frequent close to the prairie-forest
border, so its probably more important here than in NY. The heavy snowfall
merely alleviates one of the stresses on the forest, it doesn't prevent
invasive species from moving in. Terrestrial invasive plants (such as
garlic mustard, buckthorn, barberry, tatarian honeysuckle) depend on prior
invasion by European earthworms, and the reason these invasive earthworms
are less frequent in the snowbelt is because fewer people live there, so
invasion is slower. Eventually the snowbelt areas will have all the
invasive species. If anything, the snowbelt should favor European
earthworms, since the soil doesn't freeze during the winter in the snowbelt.