Saturday, March 4, 2017

emerald ash borers

i drove down to deep river park ostensibly to look at maple trees ( which i did ...however there is such variation in the morphology of the tapped trees that my unschooled mind came away without a solid mechanism for identifying them...i did take a lot of photos though ...including some of the maples in my yard which are still chock full of buds [although the lost many in the storms last week]that look very different than they did a few days ago before the weather turned cold again...there may be some merit in showing the comparison in another post ) but ran into a completely different issue..namely emerald ash borers...which have been confirmed in indiana since 2004 having migrated here as an invasive species from michigan...they originated in east asia and the hypothesis is they arrived in michigan in packaging materials from goods shipped by air or up the st. lawrence seaway to detroit and spread from there ( another bonus of the intensification of the "global" economy and the shrinking of distances...invasive species and pandemics...many of the perennials i grow are considered "invasive"...they are mostly native and not nearly this damaging )...they have arrived in the park and quite a few ash trees have been cut down in the park...some of the stumps have large holes whose origins i cannot attach a cause to, however the two stumps in the tandem trees in the last two photos each had 115 growth rings...a log life ended by a parasite...and some of the stumps are much larger...the insects can overwinter in temperatures down to minus 22 degrees fahrenheit...and even though the temperature is at freezing this morning
that is nothing like a killing temperature...and since last month has fifteen days where the "offical" high was between 51 and 69 degrees fahrenheit ( it was warmer in my back yard most of those days ) it doesn't seem like a warming climate is going to help deter the invasion...there are no ash trees in my yard and the insect seems committed tot hem yard is safe but the state is not and there would seem to be little standing in the way of the borers' spread...lines of causality coming together in the trees.

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