Thursday, July 24, 2014

Shelton's Oaks and Maples

Oak Trees:  Although there are currently many large oak trees throughout Shelton, once these trees die or fall in a storm, will there be any young oaks to take their place?  Acorns dropped by oaks each fall are an especially important food for wildlife, including deer, squirrels, and turkey. The high fat content allows animals to fatten up for winter, and acorns may be found under the snow all winter when food is scarce.  At Long Hill, none of our six study plots contained oak saplings. Off of Nells Rock Road, there were seven study plots (including the unprotected plot at Eklund) and only three oak saplings found, an average of 0.43 oaks per plot. None of the oaks was very large or vigorous. One was heavily browsed.  In contrast, the plot protected by deer fencing at Eklund had 27 very healthy oaks.

To recap:

Average number of oak saplings per plot
Long Hill: 0
Nells Rock & Eklund (unprotected): 0.4
Eklund (protected): 27

Sugar maple, the quintessential New England tree, is supposed to be the ultimate winner in the textbook "late succession" model of a forest, and in theory should be taking over our forests.  In this model, when a forest first begins growing (after a field is abandoned or most of the trees are felled), it is first dominated by fast-growing, sun-loving species.  These species create shade, so that only the saplings of slow-growing, shade-tolerant species can grow. Sugar maple and beech are such trees. The saplings can persist for many, many years in deep shade, allowing them to eventually take over a forest. Unnaturally high deer numbers upend the classic model however.  Of the 14 plots I've sampled so far in the forest, I haven't found any sugar maple saplings.  (There also weren't any in the protected plot at Eklund, but this was a dry rock hilltop where sugar maple do not grow.)  I do find beech, however, which deer will not eat unless they are starving.

I also haven't found any red maple saplings, except for one within the protected plot at Eklund. Red maples are only moderately tolerant of shade, but they are the most common tree species in Connecticut and highly tolerant of both very dry sites and very wet sites (including swamps).   If you find tree seedlings growing in your garden or gutter, they are mostly likely red maples. Yet I didn't find any red maple saplings in the unprotected study plots. I did find lots of tiny seedlings that had just sprouted this year. They sprout, grow slowly in the shade, and then they get eaten. They just aren't surviving.