(No Subject)

Spruce Longhorn Beetle but that this outbreak was not definitively tied to
the killing of healthy red spruce. Some respected insect people suggested
that the beetle was more the undertaker than a pathogen. At the time, I had
data showing that the growth rings of the pojnt pleasant park red spruce
that were cut because they were infected, had been significantly poor in
comparison with other old red spruce growth rings (surveyed at Heflers on
side of 101, taking in log piles from around the province...pictou
parrsboro queens) for the last 20 years (we MSVU students and me, did not
see this 20 year reduction in the other logs at the mill). This indicated
that the dead infected red spruce at point pleasant that upset people and
CFIA, were already on their way out and that the beetle finished them off.
At MSVU, our red spruce were cut and removed..all biomass and the bark
around stumps..and if this did not affect the spread of a disease, I am
suggesting we allow forests to have their dynamics. My own woodlot lost all
its big larch and white spruce to a beetle 5 years ago...red maple white
ash are taking up the slack and hemlock will succeed or not. It's all
carbon, it's all structure and habitat.

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Index of Subjects


The hemlock is one piece of a climate change succession and we are going to
see many forest changes. Hemlock will not disappear; some stands will be
greatly affected and be replaced by yellow birch red spruce white pine red
maple and some will remain because they are cooler, more moist and have
different nutrient balances (<N maybe).

These big responses to invasives are distractions if there are underlying
processes that drive them. We need to be united in preserving old forest
processes. We will be more supported in our pitch battles against invasives
because we are not threatening to change any land use practices.

in my view

Nick


On Thu, Mar 1, 2018 at 8:13 AM, David Simpson <david.sonsimp@gmail.com>
wrote:

> Pardon my ignorance, but, briefly, what was the red spruce saga?
>
> Thanks,
> Dave in Halifax
> On 28 Feb 2018 08:10, "John and Nhung" <nhungjohn@eastlink.ca> wrote:
>
>> There=E2=80=99s another point worth discussing:  if and possibly how les=
sons from
>> the red spruce saga could/ should be applied (or not!).
>>
>>
>>
>> *From:* naturens-owner@chebucto.ns.ca [mailto:naturens-owner@chebuct
>> o.ns.ca] *On Behalf Of *Nick Hill
>> *Sent:* February 27, 2018 3:14 PM
>> *To:* naturens@chebucto.ns.ca
>> *Subject:* RE: [NatureNS] Notice of Meeting on Hemlock Woolly Adelgid
>>
>>
>>
>> I agree, John.
>>
>> I too am leery about introducing yet another exotic to combat an exotic.
>>
>> The sanitary approach is also worrisome as that approach leaves no
>> organic no food for woodpeckers and doesn't let the tree determine its
>> fate. I just got back from a walk where I showed my sister from UK healt=
hy
>> beech and then we found a large slightly chancred beech that had overgro=
wn
>> a miserable chancred individual that had died. I had to think about the
>> possibility of differential susceptibility and evolution of resistance. =
We
>> need to give the hemlock that chance.
>>
>> And then there was the American Chestnut and its loss and replacement by
>> chestnut oak.
>>
>>
>>
>> Yes. We can do more than one thing and that's good. But I may be averse
>> to any agency that has the authority because of its name to come and cut
>> out my hemlock. They did this with the red spruce with not much ecologic=
al
>> understanding.
>>
>> Nick
>>
>>
>>
>> On Feb 27, 2018 2:26 PM, "John and Nhung" <nhungjohn@eastlink.ca> wrote:
>>
>> Good points, and I=E2=80=99d be uncomfortable with some proposed interve=
ntions.
>> Introduction of any exotic, for instance, has unpredictable consequences=
.
>>
>>
>>
>> I don=E2=80=99t think there=E2=80=99s any necessary conflict between att=
empts to preserve
>> hemlock and other sustainable forest management initiatives.  For instan=
ce,
>> I keep wondering about seed banks, which may or not be a good idea =E2=
=80=A6
>>
>>
>>
>> Hope you=E2=80=99re gonna catch some of the sessions, Nick.  The MTRI-or=
ganized
>> ones are probably more geographically conveniently-located.  You could
>> contribute substantively to the discussions!
>>
>>
>>
>> *From:* naturens-owner@chebucto.ns.ca [mailto:naturens-owner@chebuct
>> o.ns.ca] *On Behalf Of *Nick Hill
>> *Sent:* February 27, 2018 12:17 PM
>> *To:* naturens@chebucto.ns.ca
>> *Subject:* Re: [NatureNS] Notice of Meeting on Hemlock Woolly Adelgid
>>
>>
>>
>> Hi John and John
>>
>> I don't doubt that the woolly adelgid will kill hemlock trees and that i=
s
>> change and unwelcome.
>>
>> Let us first put it in a North American context with climate change and
>> atmospheric N deposition.
>>
>> We can research the impact that has occurred where the pest has moved
>> through from Virginia through New England.
>>
>> And then we can look at stand vulnerability factors. We stand to lose
>> trees and some stands. The outbreaks will be heterogenous: stands receiv=
ing
>> more N in SW Nova could be more affected. Cool ravines should be less
>> affected. Stands near the coast may be less affected because there has b=
een
>> less temperature change over the past 30 y.
>>
>>
>>
>> From what I have read, things were not wholly disastrous. The trees in
>> some infected stands were mainly killed whereas hemlocks in other stands
>> were less affected and in some, most trees survived. The carbon stays in
>> the ecosystem. This is habitat. A new forest takes shape and this normal=
ly
>> includes in the US where hemlock trees have been killed,  *Betula lenta*
>> that we dont get here and *Betula alleghaniensis* (yellow birch) that we
>> do.
>>
>>
>>
>> We should fight the things we can fight and influence such as
>> clearcutting, unnecessary roads, poor land use and wetland loss.
>>
>> We can do all measure of things: fighting invasives broadly, spraying th=
e
>> budworm with bacteria and sprays,  introducing organisms to fight adelgi=
d
>> or the sanitary removal of diseased hemlock. Or we can protect forest
>> processes by reducing cutting frequency and intensity (this will mean le=
ss
>> nutrient and organic matter, structure and carbon removal), using
>> shelterwood management (maintains shade and moisture and structure),
>> protecting by buffers ravines (shade and moisture)  and wetland corridor=
s,
>> and setting up mature forest corridors (birds, mammals, herbs...and...?)
>> throughout the forest. We cant stop this climate change but we can make =
our
>> forests as healthy as we can. The forests will be dynamic and we can
>> protect mature forest processes but not determine what the eventual fore=
st
>> will look like.
>>
>>
>>
>> Losing some hemlock stands does suck but any reactive response to adelgi=
d
>> can be seen in a larger perspective of processes.
>>
>> Let's fix unsound forestry practices and let the forest take care of
>> itself. We would be pleasantly surprised on balance. Less hemlock, more
>> yellow birch,white pine, red spruce and in 50 years, our forest may have
>> changed again.
>>
>>
>>
>> Nick
>>
>>
>>
>>
>>
>> https://etd.ohiolink.edu/ap/10?0::NO:10:P10_ETD_SUBID:76019
>>
>> a PhD thesis on hemlock riparian forest in Va and WV (K Martin 2012 Ohio
>> State)
>>
>> Hemlock forests exhibit low species richness, and thus have low
>> resiliency. In uninvaded forests of Ohio, hemlock dominates the vegetati=
on,
>> although other species are structured by environmental gradients.
>> Structural equation modeling indicates hemlock has a negative influence =
on
>> vegetation species richness, light availability and productivity. Thus, =
a
>> likely future HWA arrival will result in a complete reorganization of th=
ese
>> ecosystems, but impacts will differ across environmental gradients. Data
>> from sites impacted by HWA 9-32 years in West Virginia and Virginia
>> indicate all hemlock forests will likely be impacted. Although mortality=
 is
>> initially slowed at higher elevations and on steeper slopes with norther=
ly
>> aspects, eventually, the duration of HWA invasion is the most important
>> driver of mortality and ecosystem change. As decline progress, hemlock
>> remains dominant in sites impacted for decades, although compositions ar=
e
>> shifting and diverging across overstory hemlock decline classes. Some
>> species, including the native evergreen shrub rhododendron (Rhododendron
>> maximum) and other evergreen species including red spruce (Picea rubens)=
,
>> may be particularly influential during community reorganization.
>> Environmental gradients, including elevation and soil characteristics, a=
re
>> also important ecologial drivers. Among overstory hemlock decline
>> categories, resource availability and nutrient cycling are accelerating,
>> but this varies with environmental context.
>>
>>
>>
>> On Tue, Feb 27, 2018 at 10:18 AM, John Kearney <
>> john.kearney@ns.sympatico.ca> wrote:
>>
>> Our hemlock trees are in serious trouble.  The culprit is an aphid
>> relative, the hemlock woolly adelgid, and currently, southwest Nova Scot=
ia
>> is the most at threat.
>>
>> Find out more at 7:00 P.M. Tuesday, March 13.  The Tusket River
>> Environmental Protection Association (TREPA) will be sponsoring a talk b=
y
>> Ron Neville, Plant Health Survey Biologist of the Canadian Food Inspecti=
on
>> Agency, at the Yarmouth County Museum and Archives, 22 Collins Street,
>> Yarmouth
>> <https://maps.google.com/?q=3D22+Collins+Street,+Yarmouth&entry=3Dgmail&=
source=3Dg>.
>> All welcome.
>>
>> Questions?  Contact John Sollows at 742-2802.
>>
>>
>>
>>
>>
>> --
>>
>> Dr. N.M.Hill
>> Fern Hill Institute of Plant Conservation
>> 424 Bentley Road, Berwick, NS, B0P 1E0
>> <https://maps.google.com/?q=3D424+Bentley+Road,+Berwick,+NS,+B0P+1E0&ent=
ry=3Dgmail&source=3Dg>
>>
>> phone 902-698-0416 <(902)%20698-0416>
>>
>


--=20
Dr. N.M.Hill
Fern Hill Institute of Plant Conservation
424 Bentley Road, Berwick, NS, B0P 1E0

phone 902-698-0416

--f403045f8bd6f30d4905665c08e9
Content-Type: text/html; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr"><div class=3D"gmail_default" style=3D"">From my perspectiv=
e, Dave, there was certainly an outbreak of the Brown Spruce Longhorn Beetl=
e but that this outbreak was not definitively tied to the killing of health=
y red spruce. Some respected insect people suggested that the beetle was mo=
re the undertaker than a pathogen. At the time, I had data showing that the=
 growth rings of the pojnt pleasant park red spruce that were cut because t=
hey were infected, had been significantly poor in comparison with other old=
 red spruce growth rings (surveyed at Heflers on side of 101, taking in log=
 piles from around the province...pictou parrsboro queens) for the last 20 =
years (we MSVU students and me, did not see this 20 year reduction in the o=
ther logs at the mill). This indicated that the dead infected red spruce at=
 point pleasant that upset people and CFIA, were already on their way out a=
nd that the beetle finished them off.</div><div class=3D"gmail_default" sty=
le=3D"">At MSVU, our red spruce were cut and removed..all biomass and the b=
ark around stumps..and if this did not affect the spread of a disease, I am=
 suggesting we allow forests to have their dynamics. My own woodlot lost al=
l its big larch and white spruce to a beetle 5 years ago...red maple white =
ash are taking up the slack and hemlock will succeed or not. It&#39;s all c=
arbon, it&#39;s all structure and habitat.</div><div class=3D"gmail_default=
" style=3D""><br></div><div class=3D"gmail_default" style=3D"">The hemlock =
is one piece of a climate change succession and we are going to see many fo=
rest changes. Hemlock will not disappear; some stands will be greatly affec=
ted and be replaced by yellow birch red spruce white pine red maple and som=
e will remain because they are cooler, more moist and have different nutrie=
nt balances (&lt;N maybe).</div><div class=3D"gmail_default" style=3D""><br=
></div><div class=3D"gmail_default" style=3D"">These big responses to invas=
ives are distractions if there are underlying processes that drive them. We=
 need to be united in preserving old forest processes. We will be more supp=
orted in our pitch battles against invasives because we are not threatening=
 to change any land use practices.</div><div class=3D"gmail_default" style=
=3D""><br></div><div class=3D"gmail_default" style=3D"">in my view</div><di=
v class=3D"gmail_default" style=3D""><br></div><div class=3D"gmail_default"=
 style=3D"">Nick</div><div class=3D"gmail_default" style=3D""><br></div></d=
iv><div class=3D"gmail_extra"><br><div class=3D"gmail_quote">On Thu, Mar 1,=
 2018 at 8:13 AM, David Simpson <span dir=3D"ltr">&lt;<a href=3D"mailto:dav=
id.sonsimp@gmail.com" target=3D"_blank">david.sonsimp@gmail.com</a>&gt;</sp=
an> wrote:<br><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;=
border-left:1px #ccc solid;padding-left:1ex"><p dir=3D"ltr">Pardon my ignor=
ance, but, briefly, what was the red spruce saga? </p>
<p dir=3D"ltr">Thanks,<br>
Dave in Halifax</p><div class=3D"HOEnZb"><div class=3D"h5">
<div class=3D"gmail_quote">On 28 Feb 2018 08:10, &quot;John and Nhung&quot;=
 &lt;<a href=3D"mailto:nhungjohn@eastlink.ca" target=3D"_blank">nhungjohn@e=
astlink.ca</a>&gt; wrote:<br type=3D"attribution"><blockquote class=3D"gmai=
l_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left=
:1ex"><div lang=3D"EN-CA" link=3D"blue" vlink=3D"purple"><div class=3D"m_60=
45595270473388462m_-6940882908857009511WordSection1"><p class=3D"MsoNormal"=
><span style=3D"font-size:11.0pt;font-family:&quot;Calibri&quot;,&quot;sans=
-serif&quot;;color:#1f497d">There=E2=80=99s another point worth discussing:=
=C2=A0 if and possibly how lessons from the red spruce saga could/ should b=
e applied (or not!).<u></u><u></u></span></p><p class=3D"MsoNormal"><span s=
tyle=3D"font-size:11.0pt;font-family:&quot;Calibri&quot;,&quot;sans-serif&q=
uot;;color:#1f497d"><u></u>=C2=A0<u></u></span></p><p class=3D"MsoNormal"><=
b><span lang=3D"EN-US" style=3D"font-size:10.0pt;font-family:&quot;Tahoma&q=
uot;,&quot;sans-serif&quot;">From:</span></b><span lang=3D"EN-US" style=3D"=
font-size:10.0pt;font-family:&quot;Tahoma&quot;,&quot;sans-serif&quot;"> <a=
 href=3D"mailto:naturens-owner@chebucto.ns.ca" target=3D"_blank">naturens-o=
wner@chebucto.ns.ca</a> [mailto:<a href=3D"mailto:naturens-owner@chebucto.n=
s.ca" target=3D"_blank">naturens-owner@chebuct<wbr>o.ns.ca</a>] <b>On Behal=
f Of </b>Nick Hill<br><b>Sent:</b> February 27, 2018 3:14 PM<br><b>To:</b> =
<a href=3D"mailto:naturens@chebucto.ns.ca" target=3D"_blank">naturens@chebu=
cto.ns.ca</a><br><b>Subject:</b> RE: [NatureNS] Notice of Meeting on Hemloc=
k Woolly Adelgid<u></u><u></u></span></p><p class=3D"MsoNormal"><u></u>=C2=
=A0<u></u></p><div><p class=3D"MsoNormal">I agree, John.<u></u><u></u></p><=
div><p class=3D"MsoNormal">I too am leery about introducing yet another exo=
tic to combat an exotic.<u></u><u></u></p></div><div><p class=3D"MsoNormal"=
>The sanitary approach is also worrisome as that approach leaves no organic=
 no food for woodpeckers and doesn&#39;t let the tree determine its fate. I=
 just got back from a walk where I showed my sister from UK healthy beech a=
nd then we found a large slightly chancred beech that had overgrown a miser=
able chancred individual that had died. I had to think about the possibilit=
y of differential susceptibility and evolution of resistance. We need to gi=
ve the hemlock that chance.<u></u><u></u></p></div><div><p class=3D"MsoNorm=
al">And then there was the American Chestnut and its loss and replacement b=
y chestnut oak.<u></u><u></u></p></div><div><p class=3D"MsoNormal"><u></u>=
=C2=A0<u></u></p></div><div><p class=3D"MsoNormal">Yes. We can do more than=
 one thing and that&#39;s good. But I may be averse to any agency that has =
the authority because of its name to come and cut out my hemlock. They did =
this with the red spruce with not much ecological understanding.<u></u><u><=
/u></p></div><div><p class=3D"MsoNormal">Nick<u></u><u></u></p></div></div>=
<div><p class=3D"MsoNormal"><u></u>=C2=A0<u></u></p><div><p class=3D"MsoNor=
mal">On Feb 27, 2018 2:26 PM, &quot;John and Nhung&quot; &lt;<a href=3D"mai=
lto:nhungjohn@eastlink.ca" target=3D"_blank">nhungjohn@eastlink.ca</a>&gt; =
wrote:<u></u><u></u></p><div><div><p class=3D"MsoNormal"><span style=3D"fon=
t-size:11.0pt;font-family:&quot;Calibri&quot;,&quot;sans-serif&quot;;color:=
#1f497d">Good points, and I=E2=80=99d be uncomfortable with some proposed i=
nterventions.=C2=A0 Introduction of any exotic, for instance, has unpredict=
able consequences.</span><u></u><u></u></p><p class=3D"MsoNormal"><span sty=
le=3D"font-size:11.0pt;font-family:&quot;Calibri&quot;,&quot;sans-serif&quo=
t;;color:#1f497d">=C2=A0</span><u></u><u></u></p><p class=3D"MsoNormal"><sp=
an style=3D"font-size:11.0pt;font-family:&quot;Calibri&quot;,&quot;sans-ser=
if&quot;;color:#1f497d">I don=E2=80=99t think there=E2=80=99s any necessary=
 conflict between attempts to preserve hemlock and other sustainable forest=
 management initiatives.=C2=A0 For instance, I keep wondering about seed ba=
nks, which may or not be a good idea =E2=80=A6</span><u></u><u></u></p><p c=
lass=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:&quot;Calibr=
i&quot;,&quot;sans-serif&quot;;color:#1f497d">=C2=A0</span><u></u><u></u></=
p><p class=3D"MsoNormal"><span style=3D"font-size:11.0pt;font-family:&quot;=
Calibri&quot;,&quot;sans-serif&quot;;color:#1f497d">Hope you=E2=80=99re gon=
na catch some of the sessions, Nick.=C2=A0 The MTRI-organized ones are prob=
ably more geographically conveniently-located.=C2=A0 You could contribute s=
ubstantively to the discussions!</span><u></u><u></u></p><p class=3D"MsoNor=
mal"><span style=3D"font-size:11.0pt;font-family:&quot;Calibri&quot;,&quot;=
sans-serif&quot;;color:#1f497d">=C2=A0</span><u></u><u></u></p><p class=3D"=
MsoNormal"><b><span lang=3D"EN-US" style=3D"font-size:10.0pt;font-family:&q=
uot;Tahoma&quot;,&quot;sans-serif&quot;">From:</span></b><span lang=3D"EN-U=
S" style=3D"font-size:10.0pt;font-family:&quot;Tahoma&quot;,&quot;sans-seri=
f&quot;"> <a href=3D"mailto:naturens-owner@chebucto.ns.ca" target=3D"_blank=
">naturens-owner@chebucto.ns.ca</a> [mailto:<a href=3D"mailto:naturens-owne=
r@chebucto.ns.ca" target=3D"_blank">naturens-owner@chebuct<wbr>o.ns.ca</a>]=
 <b>On Behalf Of </b>Nick Hill<br><b>Sent:</b> February 27, 2018 12:17 PM<b=
r><b>To:</b> <a href=3D"mailto:naturens@chebucto.ns.ca" target=3D"_blank">n=
aturens@chebucto.ns.ca</a><br><b>Subject:</b> Re: [NatureNS] Notice of Meet=
ing on Hemlock Woolly Adelgid</span><u></u><u></u></p><p class=3D"MsoNormal=
">=C2=A0<u></u><u></u></p><div><div><p class=3D"MsoNormal">Hi John and John=
<u></u><u></u></p></div><div><p class=3D"MsoNormal">I don&#39;t doubt that =
the woolly adelgid will kill hemlock trees and that is change and unwelcome=
.<u></u><u></u></p></div><div><p class=3D"MsoNormal">Let us first put it in=
 a North American context with climate change and atmospheric N deposition.=
<u></u><u></u></p></div><div><p class=3D"MsoNormal">We can research the imp=
act that has occurred where the pest has moved through from Virginia throug=
h New England.<u></u><u></u></p></div><div><p class=3D"MsoNormal">And then =
we can look at stand vulnerability factors. We stand to lose trees and some=
 stands. The outbreaks will be heterogenous: stands receiving more N in SW =
Nova could be more affected. Cool ravines should be less affected. Stands n=
ear the coast may be less affected because there has been less temperature =
change over the past 30 y.=C2=A0<u></u><u></u></p></div><div><p class=3D"Ms=
oNormal">=C2=A0<u></u><u></u></p></div><div><p class=3D"MsoNormal">From wha=
t I have read, things were not wholly disastrous. The trees in some infecte=
d stands were mainly killed whereas hemlocks in other stands were less affe=
cted and in some, most trees survived. The carbon stays in the ecosystem. T=
his is habitat. A new forest takes shape and this normally includes in the =
US where hemlock trees have been killed,=C2=A0=C2=A0<i>Betula lenta</i> tha=
t we dont get here and <i>Betula alleghaniensis</i> (yellow birch) that we =
do.=C2=A0<u></u><u></u></p></div><div><p class=3D"MsoNormal">=C2=A0<u></u><=
u></u></p></div><div><p class=3D"MsoNormal">We should fight the things we c=
an fight and influence such as clearcutting, unnecessary roads, poor land u=
se and wetland loss.<u></u><u></u></p></div><div><p class=3D"MsoNormal">We =
can do all measure of things: fighting invasives broadly, spraying the budw=
orm with bacteria and sprays,=C2=A0 introducing organisms to fight adelgid =
or the sanitary removal of diseased hemlock. Or we can protect forest proce=
sses by reducing cutting frequency and intensity (this will mean less nutri=
ent and organic matter, structure and carbon removal), using shelterwood ma=
nagement (maintains shade and moisture and structure), protecting by buffer=
s ravines (shade and moisture)=C2=A0 and wetland corridors, and setting up =
mature forest corridors (birds, mammals, herbs...and...?) throughout the fo=
rest. We cant stop this climate change but we can make our forests as healt=
hy as we can. The forests will be dynamic and we can protect mature forest =
processes but not determine what the eventual forest will look like.<u></u>=
<u></u></p></div><div><p class=3D"MsoNormal">=C2=A0<u></u><u></u></p></div>=
<div><p class=3D"MsoNormal">Losing some hemlock stands does suck but any re=
active response to adelgid can be seen in a larger perspective of processes=
.=C2=A0<u></u><u></u></p></div><div><p class=3D"MsoNormal">Let&#39;s fix un=
sound forestry practices and let the forest take care of itself. We would b=
e pleasantly surprised on balance. Less hemlock, more yellow birch,white pi=
ne, red spruce and in 50 years, our forest may have changed again.<u></u><u=
></u></p></div><div><p class=3D"MsoNormal">=C2=A0<u></u><u></u></p></div><d=
iv><p class=3D"MsoNormal">Nick<u></u><u></u></p></div><div><p class=3D"MsoN=
ormal">=C2=A0<u></u><u></u></p></div><div><p class=3D"MsoNormal">=C2=A0<u><=
/u><u></u></p></div><div><p class=3D"MsoNormal"><a href=3D"https://etd.ohio=
link.edu/ap/10?0::NO:10:P10_ETD_SUBID:76019" target=3D"_blank">https://etd.=
ohiolink.edu/ap/10<wbr>?0::NO:10:P10_ETD_SUBID:76019</a><u></u><u></u></p><=
/div><div><p class=3D"MsoNormal">a PhD thesis on hemlock riparian forest in=
 Va and WV (K Martin 2012 Ohio State)<u></u><u></u></p></div><div><p class=
=3D"MsoNormal"><span style=3D"font-size:9.0pt;font-family:&quot;Helvetica&q=
uot;,&quot;sans-serif&quot;;color:#404040;background:white">Hemlock forests=
 exhibit low species richness, and thus have low resiliency. In uninvaded f=
orests of Ohio, hemlock dominates the vegetation, although other species ar=
e structured by environmental gradients. Structural equation modeling indic=
ates hemlock has a negative influence on vegetation species richness, light=
 availability and productivity. Thus, a likely future HWA arrival will resu=
lt in a complete reorganization of these ecosystems, but impacts will diffe=
r across environmental gradients. Data from sites impacted by HWA 9-32 year=
s in West Virginia and Virginia indicate all hemlock forests will likely be=
 impacted. Although mortality is initially slowed at higher elevations and =
on steeper slopes with northerly aspects, eventually, the duration of HWA i=
nvasion is the most important driver of mortality and ecosystem change. As =
decline progress, hemlock remains dominant in sites impacted for decades, a=
lthough compositions are shifting and diverging across overstory hemlock de=
cline classes. Some species, including the native evergreen shrub rhododend=
ron (Rhododendron maximum) and other evergreen species including red spruce=
 (Picea rubens), may be particularly influential during community reorganiz=
ation. Environmental gradients, including elevation and soil characteristic=
s, are also important ecologial drivers. Among overstory hemlock decline ca=
tegories, resource availability and nutrient cycling are accelerating, but =
this varies with environmental context.=C2=A0</span> <u></u><u></u></p></di=
v></div><div><p class=3D"MsoNormal">=C2=A0<u></u><u></u></p><div><p class=
=3D"MsoNormal">On Tue, Feb 27, 2018 at 10:18 AM, John Kearney &lt;<a href=
=3D"mailto:john.kearney@ns.sympatico.ca" target=3D"_blank">john.kearney@ns.=
sympatico.ca</a>&gt; wrote:<u></u><u></u></p><div><div><p class=3D"MsoNorma=
l">Our hemlock trees are in serious trouble.=C2=A0 The culprit is an aphid =
relative, the hemlock woolly adelgid, and currently, southwest Nova Scotia =
is the most at threat.<u></u><u></u></p><p class=3D"MsoNormal">Find out mor=
e at 7:00 P.M. Tuesday, March 13.=C2=A0 The Tusket River Environmental Prot=
ection Association (TREPA) will be sponsoring a talk by Ron Neville, Plant =
Health Survey Biologist of the Canadian Food Inspection Agency, at the Yarm=
outh County Museum and Archives, <a href=3D"https://maps.google.com/?q=3D22=
+Collins+Street,+Yarmouth&amp;entry=3Dgmail&amp;source=3Dg" target=3D"_blan=
k">22 Collins Street, Yarmouth</a>.=C2=A0 All welcome.<u></u><u></u></p><p =
class=3D"MsoNormal">Questions?=C2=A0 Contact John Sollows at 742-2802.<u></=
u><u></u></p></div></div></div><p class=3D"MsoNormal"><br><br clear=3D"all"=
><u></u><u></u></p><div><p class=3D"MsoNormal">=C2=A0<u></u><u></u></p></di=
v><p class=3D"MsoNormal">-- <u></u><u></u></p><div><p class=3D"MsoNormal">D=
r. N.M.Hill<br>Fern Hill Institute of Plant Conservation<br><a href=3D"http=
s://maps.google.com/?q=3D424+Bentley+Road,+Berwick,+NS,+B0P+1E0&amp;entry=
=3Dgmail&amp;source=3Dg" target=3D"_blank">424 Bentley Road, Berwick, NS, B=
0P 1E0</a><br><br>phone <a href=3D"tel:(902)%20698-0416" target=3D"_blank">=
902-698-0416</a><u></u><u></u></p></div></div></div></div></div></div></div=
></div></blockquote></div>
</div></div></blockquote></div><br><br clear=3D"all"><div><br></div>-- <br>=
<div class=3D"gmail_signature" data-smartmail=3D"gmail_signature">Dr. N.M.H=
ill<br>Fern Hill Institute of Plant Conservation<br>424 Bentley Road, Berwi=
ck, NS, B0P 1E0<br><br>phone 902-698-0416</div>
</div>

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