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All,   &
Hi Rick, Fritz & All, Apr 28, 2012
Once again I would caution against shooting the messenger. Bark beetles
and Spruce got along fine for untold thousands of years. Beetle activity is
likely a symptom of some underlying problem that begs for study and perhaps
solution.
Especially over the last 20 years, huge areas of Spruce have died and
this beetle and no doubt other Bark Beetles have been present in large
numbers. But I think the real problem is air pollution; low-level ozone,
acid rain and perhaps other unrecognized air pollutants (or other stresses).
In a nutshell, I think our trees die and Bark Beetles have a field day
because the trees are weakened way before their time.
Consider a few contrasts.
1) The gov site says White Spruce matures at about 50 years of age whereas
http://www.gardenguides.com/taxonomy/white-spruce-picea-glauca/
says White Spruce lives up to 300 years on good sites protected from fire
and up to 1000 years near the tree line. Native Trees of Canada (1961)says
WS may reach a height of 120' and a diameter of 4', averages being 80' and
2' respectively. Darn few WS trees reach 2' DBH today.
2) The gov site says to clean up blowdowns ASAP; more than 2 blowdowns/ha
are a prime source of outbreaks as are high stumps, cull logs and large
diameter slash. If the trees were healthy then having deadwood present,
where beetles could feed, would not be a danger to live trees.
3) The gov site says "If the tree is weak from numerous attacks, little or
no sap may be visable." One might perhaps more correctly reverse these
components; "If the tree is weak then little or no sap will flow when
beetles drill holes and attacks will consequently be numerous."
4) The gov site says "When beetle populations are low, the trees are able to
resist attack". Or is it the other way around ? "When trees are able to
resist attack, beetle populations are low."
5) The gov site says "Older trees are not able to produce the extra sap
necessary to "pitch out" the invading adult beetle". Amen to that if "Older"
is replaced by "Stressed".
6) The pitch tubes mentioned in Detection are I think evidence of trees so
weakened that pitch flows so slowly that it dries before it can flow
downward (and beetles likely get through the layer containing resin canals
before there is enough flow to prevent entry) . Pitch tubes were numerous in
North Alton in 2000. [They were also mentioned at about this time as being
characteristic of BSLB].
We don't need to reinvent the wheel but at least should have current
measures of known problem air pollutants [Is this being done ?]. There have
been numerous studies of e.g. Waldsterben, first associated with acid rain
and more recently with pollutants generated by high-speed traffic on the
autobahn (saw the latter recently but can't recall where). NS and especially
the Valley is the tail pipe of Eastern North America.
There have been some measurements of low-level ozone I think but where
and for how long I don't know. Rather than ramble on and on I will cut this
part short by asking if anyone knows the current state of air pollution
monitoring here.
Why bother ? Well, e.g. if we could show that 80% of our pollution comes
from the US then that could be used as a lever in trade negotiations.etc or
even a basis for compensation.
Injury caused by air pollutants increases nutrient loss by leaching from
leaves. So a tree that is already weakened has to expend metabolic energy
just to get back to where it was before the last drizzle.
We have a 'problem' with disposal of biosolids. It is just possible that
very light applications of biosolids to woodland would kill two birds with
one stone.
Trying to find answers is I think preferable to sleep-walking into a
crisis which so far as I know sums up Forestry research here over the last
40 years or so.
Yt, Dave Webster, Kentville
----- Original Message -----
From: "Rick Whitman" <dendroica.caerulescens@gmail.com>
To: <naturens@chebucto.ns.ca>
Sent: Saturday, April 28, 2012 2:44 PM
Subject: Re: [NatureNS] Beetles, forests, and climate change: Exchanging old
mistakes for new?
> "trying to eradicate" is a well-chosen phrase, intended or not. Native
> species (1) are never eradicated & funds spent on such are a bigger
> mistake than BSLB. At least that one had the political (US) rationale.
> I suspect there are few here who fully understand how spurious
> phytosanitary issues are used aggressively by various US producer
> groups, but Chris' example re potato wart is certainly one of the
> best. US forestry & agricultural producer groups are aware of exactly
> one objective: "winning".
>
> (1)
> http://www.gov.ns.ca/natr/forestprotection/foresthealth/sheets/spruceb1.pdf
>
> Rick Whitman
>
> On Sat, Apr 28, 2012 at 12:49 PM, Fritz McEvoy <fritzmcevoy@hotmail.com>
> wrote:
>> Hi Chris, Dave and All;
>> The really sad thing about this story is that all the money wasted on
>> BSLB mitigation could have been better spent trying to eradicate the real
>> scourge of softwood forests in N.S., the (Red) Spruce Bark Beetle
>> - Dendroctonus rufipennis Kirby, which is/has destroying hundreds, if not
>> thousands, of acres of prime softwood forests in Nova Scotia over the
>> last
>> decade. The battle to get this pest under control seems nearly
>> non-existent;
>> at least to me up here in the highlands. All the best.
>> Fritz McEvoy
>> Sunrise Valley, CB
>
>
> -----
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