Habitat Fragmentation in Martten Habitat

[msawyer]

Hello all...

I have been reading the scientific literature relating to forest fragmentation (ie industrial forest harvesting) and effects on marten and marten habitat... While the general sense is that clear cutting is not good for marten, there is some evidence that relatively young regenerated cutblocks can make good martin habitat if there is enough structure (ie debris, downed logs, ect). But I'm not convinced...

So, based on your experiences on your trap lines, what can you say about the implications of forest harvesting on your line on marten? And what about other species? In the end, is forest harvesting a plus, a negative or just neutral and if so, why?

Your thoughts?

Best regards

Mike

ps. I know many might respond in the context of the massive forest liquidation that has or will result from the mountain pine beetle (MPB) infestation, but for the purposes of this question, can we assume that we are ignoring the MPB issue...

[Rocks]

I owned and trapped a line here in Alberta on the Kakwa for a few years, about half of it had been logged in a checkerboard pattern in the 50's-70's. It was also in the middle of an oil field so lots of lease roads, but some good timbered areas left as well. It was a good marten line. I caught maybe a third of my marten in the regrown cutblocks. Just my personal experience on one line.

I know the new cutblocks suck for marten production, but give them a few years.

[Yellow Dog]

Good question - my experience from 30 years of trapping & working in the timber industry is that harvesting has a very short term impact on marten habitat & populations, particularly if the trapper & company work together. on my own line and focused my marten trapping efforts on the roads/cut blocks and immediate adjacent areas to capture any dispaced marten. Once the logging was done I moved to other areas and found that within 10 years I could trap reasonable numbers off cut blocks & adjacent leave timber & corridors.
I had a friend logging in the upper South Ram River area explain a similar experience to me.
We also have to remember that forest fires or what we may consider as natures way often consumed huge areas of timber. Historically, what impacts did that have?
Specific to fragmentation, the issue is more the size & frequency of cut blocks and the resulting roads. In the 1990's the environmental movement was forcing small area blocks on the landscape without the input or acceptance of science from biologists & foresters. In the late 1990's and early 2000's science has prevailed somewhat to allow for a more even & mixed area distribution of cut block areas. Large harvest and leave areas lessen "fragmentation" but are not great for all species so the best is to try to mimic nature and vary the size & distribution of cut areas much like forest fires - some very large, some very small, and a large number that range inbetween - and in the larger areas leave stand structure (stepping stones/hiding areas) spread throughout.
Aside from marten we need to consider all species and as forest management considers biodiversity (species, age distribution, density, etc.), we too need to consider the biodiversity in target species we achieve from logging, forest fires, etc. Marten always have been a profitable target (price, ease of trapping, lower cost, easy to prepare) but a good lynx of wolf catch is something to be proud of too.

Good Trapping!

[Brian Bildson]

I don't know about a few years for those cutblocks Rocks. I also have a line on the Kakwa and I do not see marten in the regrowth.

These cuts are from the late 60's onwards so they've had lots of time. The issue is not a lack of cover but rather monoculture foresty practices. These pine plantations are pretty barren compared to old growth or aspen forest. Clear cuts also favor mice species while martens prefer red backed voles.
I do see marten passing through but not sticking around.

However in aspen FMA's the regrowth is more natural and varied. When I moved here from the NWT I was amazed to see the numbers of martens in the aspen forest.

The question was whether logging was a negative influence on marten habitat. The answer is Yes, No, & Sometimes. Depends to what extent and what habitat. From what I can see some is OK, but I'm disturbed by the extent of logging I'm seeing. It is not sustainable at this pace.

[bullgetter]

When setting for marten I don't bother setting to close to the cuts or in the regrowth. I will place a set in standing timber between cutblocks. I figure they act as a funnel for traveling marten. The stands of regrowth pine or even uncut pine stands where the trees are only 8 inch diameter does not produce for me. I find that there needs to be undergrowth for the voles and such to bring the marten in. Stunted pine stands are pretty barren on the ground especially in sandy areas. I like to set in the mixed areas with good undergrowth, pine, spruce, poplar and alder all together. Works for me.