Josie writes "The October 2007 issue of Smithsonian magazine had an interesting article called "Teaming Up With Thoreau," about how "One hundred fifty years after the publication of Walden, Henry David Thoreau is helping scientists monitor global warming" (60).  Richard Primack of Boston University, in his own study of how the natural world was reacting to climate change, needed data from the past to compare his more recent observations of the Concord area to.  He found that Thoreau had collected just such data.

The Upper Cumberland Sierra Club has long had its own "Thoreau":  Richard Simmers, also, like Thoreau, Harvard educated, with a Ph.D. in ornithology from Cornell.  The UC Sierra Club has been publishing Dr. Simmers' observations or "Field Notes" in our newsletter since 1994, and in the year 2000 we collected all of these newsletters into a soft-bound book.  Recently, his columns have been appearing in the Tennes-Sierran, because his "Field Notes" had such a broad appeal."
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I observed a good many early flowers in January including a Drummond-type red maple (chromosome number 2n= 56; fruits about twice the size of most red maples; young leaves white-fuzzy underneath) in flower January 8 at the Tennessee Tech campus (this tree had started February 1 in 2006 and as of February 8, 2008, had begun opening flowers).  Some ordinary red maples (hexaploid, 2n=78 or octoploid, 2n=104) had begun to open flowers at TTU by February 1, and many red maples here had started by March 2.  The silver maple on Poplar Grove road that I check annually was in full bloom February 24-28, quite late; it had open flowers January 29, 2006, and was in full bloom February 3, 2006 and February 15, 2005.

Silver maples fruited heavily in 2007, often to the extent of slowing leafing out, as did elms. (American Elms especially) and many red maples.  My experience over 30 years in Tennessee has been that this pattern is correlated with April freezes.  If, on the contrary, elms and maples have few or no fruits, April freezes would be absent; elms and silver maple flower annually, and a lack of fruits indicates freezes when in bloom (February-early March).  Several Drummond maples at TTU had ripened fruits before the freeze, but red maples east of Monterey had their fruits frozen in late March, trees that bloom early came into full flower, often a week or two early and we had glorious show before the freeze ended it.  Redbuds had begun flowering by March 20 in west Putnam County (earlier in Nashville), March 26 near Monterey; they had finished blooming west of Cookeville before April!  Flowering dogwoods, even on the Cumberland Plateau, had begun to bloom late in March; paulownia had begun April 1 in Cookeville, black locust and crossvine by April 3 in middle Tennessee!!

I saw my earliest ever pink daisy fleabanes on March 28 at Barnes Hollow (east of Cookeville).  Oaks, hickories, walnuts, apples, cherries, peaches, pears, all came into bloom - and most of these froze with the great Easter weekend freezeout, as did all of Hector Black's blueberries in Jackson County.  On Good Friday (April 6), frost hit as an Arctic cold front came in and ravaged the vegetation; night temperatures fell to about 20 degrees in Nashville and colder in low outlying valleys.  Most of the new foliage turned shades of tan, rust, sepia, or charcoal; some of this, on oaks notably, was still hanging on trees in July.  Some evergreens were hard hit; boxwoods and euonymus (both exotics) looked like they had toppings of whipped cream, fading to butterscotch.  All new growth on hollies blackened; many yews in Monterey had major injury, looking largely rusty in July.  Southern magnolias, on the other hand, came through nicely (they leaf out late).  Our hillsides looked like they had been scorched by fire, especially in areas with tulip "poplars" or hickories (ugly charcoal blobs for weeks).  This was the worst spring freeze I can remember.

Most of our native sugar and red maples stayed green through the freeze and began to grow again in late April; but the sugar maple's young fruits were frozen.  Boxelder foliage mostly froze (they can stand light frosts).  Wild cherry trees, and most fruit trees, had foliage that remained unfrozen.  A few oaks on warm sites kept their leaves, many on the plateau, which normally come out late anyway, were not much bothered.  The Plateau oaks began leafing out in late April, with the height of the "pastel-pink" tints around April 25 - May 2; some white oaks had an acorn crop in the fall!  Some walnut trees also had nuts.

The Eastertime freezes were an extreme of the "dogwood winter" pattern normal enough in Tennessee.  (All dogwood flowers and much foliage was frozen in Putnam County, at least on the Plateau; dogwoods can stand some frost).  Over millennia, the natural selective processes of weather extremes have eliminated unfit individuals from the various gene pools, so native flora should not be seriously bothered; exotics are another matter.

Recovery was often slow, but by the end of May most trees had considerable new foliage, except for various exotics such as Japanese maples.  Hackberry trees normally have two flushes of foliage when they bloom, the earlier flush with the flowers.  In early April in Nashville (before freezes) I observed young fruits among the new leaves.  Most hackberries were defoliated by the freezes, losing their fruit crop.  On April 24, I finally saw a few new leaves on one Nashville hackberry tree; by May 2 there was much more green foliage on the hackberries, also on white ashes and many others.

After the freezes came mostly dry to droughty weather, although July on the Plateau had near normal rainfall.  Most amphibians had a very poor breeding season if they bred in the spring; water levels fell over two feet in some of my permanent ponds on the Plateau, but I still had enough water in them to water my plants.  I did lose my mulberries, from cambium injury likely in part.

As if to compensate for the injury from the spring freezes, the fall foliage on and near the Cumberland Plateau was sumptuous, peaking again in early November even on the Plateau.  I spent hours on my place east of Monterey "soaking up" the colors.  White oaks were often shades of purple, or ruby-red in some areas.  The hickories, so blighted-looking in the spring, were a glorious golden yellow.  Scarlet oaks and sourwoods were more vividly colored than usual.