That agrees with this quote:
"Questions have also emerged about the well-publicized relationship between
wolves and willows. Marshall and two colleagues investigated the controls on
willow shrubs by examining ten years’ worth of data from open plots and plots
surrounded by cages to keep the elk out. Her team
found8<http://www.nature.com/news/rethinking-predators-legend-of-the-wolf-1.14841#b8>
that the willows were not thriving in all the protected sites. The only plants
that grew above 2 metres — beyond the reach of browsing elk — were those in
areas where simulated beaver dams had raised the water table."
I.e it may be true that wolves protect willows, but it only helps near water.
Peter Shute
Sent from my iPad
On 6 Apr 2014, at 10:31 am, "Sonja Ross"
<<>> wrote:
Hi Peter,
What our guide, Tom Murphy, a photographer who has assisted wildlife
productions such as those done by David Attenborough, and who lives not far
from the park so is there often, was that elk had eaten down the willows that
grow along streams etc which meant for example that there was no food for
beavers, nor branches to form their lodges. The willows would probably be a
more likely tree to stabilise stream banks than aspen, so maybe the aspen issue
is only part of the story.
Sonja
On 06/04/2014, at 10:20 AM, Peter Shute
<<>> wrote:
From that article:
"When Kauffman and his colleagues studied aspen in areas where risk of attack
by wolves was high or low, they obtained results different from Ripple’s.
Rather than look at the five tallest aspen in each stand, as Ripple had done,
they tallied the average tree height and used locations of elk kills to map the
risk of wolf attacks. By these measures, they found no differences between
trees in high- and low-risk areas."
So some people are getting excited about tree regrowth that might be attributed
to the presence of wolves, but others are arguing about whether there's been
any regrowth at all.
Anyone else confused?
Peter Shut
Sent from my iPhone
On 4 Apr 2014, at 3:51 pm, "Ross Macfarlane"
<<><m("tpg.com.au","rmacfarl");">>>
wrote:
It's a fascinating narrative, but like most things maybe not as simple as it
sounds -
http://www.nature.com/news/rethinking-predators-legend-of-the-wolf-1.14841
-----Original Message-----
From: Clive Nealon
Sent: Friday, April 04, 2014 11:19 AM
To: Birding-Aus
Subject: [Birding-Aus] A vote for conservation...
A really interesting short clip on the benefits of wolves in Yellowstone N
P.
Perhaps a lesson that would translate to other areas...
http://devour.com/video/how-wolves-change-rivers/
Clive.
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