Chestnuts

I remember an article in the Globe written by Chet Raymo several decades ago telling of a remnant population of bluebirds at Sheep Pasture. Bluebirds were in trouble due to competition for nest sites with starlings and English sparrows. In the following decades through the work of Wild Birds Unlimited's Bob Hurd with help from Doc Everett, Bob Benson, and many others bluebirds have made a huge comeback. At Sheep Pasture Bob Benson maintains a series of nests that is part of a trail that now stretches from Wheaton Farm through Stoughton. We're very proud of our role in reestablishing a native species, and soon we'll have the chance to start on a new species.

Last evening John Grant, long time member of the Conservation Commission, spoke about his  dream of restoring the American chestnut to Easton. The American chestnut once was the dominant tree in southern New England's forest. Their reliable nut production fed wildlife and people alike, and they also provided some of the best lumber. About a century ago a blight killed over 4 billion chestnut trees reducing the wildlife that depended on them by 60 percent. Today, chestnuts still sprout from the stumps of these dead giants, but these sprouts seldom live long enough to produce nuts.

The Chestnut has many friends like John who have spent decades trying to produce a blight resistant tree. The Chinese chestnut is blight resistant, but it doesn't have tasty nuts or high quality timber. Just as you might cross two varieties of tomatoes to create a new hybrid, people have been crossing American chestnuts and their Chinese cousins. Unlike tomatoes, however, these chestnut crossses take years to prove themselves. Success looked near about a decade ago until it was determined that the trees with the best blend of blight resistance and American qualities didn't pass these traits on in their nuts. It's one thing to plant a blight resistant single tree, but if the chestnut is to truly recover it has to help itself, or more precisely squirrels have to help by hiding and forgetting about some of the one to two bushels of nuts produced annually by a mature tree.

John announced last night the arrival of trees that are 15/16th American chestnut with all the qualities of the original plus blight resistance and viable nuts. Sheep Pasture has been chosen as one site for field testing the new plants. It is a perfect time for us as we begin implementing a new ten year forestry plan. Yes, folks we will be chopping down trees at Sheep Pasture as well as planting new ones. More on that after a big meeting next week!

Triple E Spraying

Auto accidents caused by deer kill 130 people a year. Bee stings kill about 50 people a year. Bites from black widow or brown recluse spiders kill about 6 people a year. Eastern Equine Encephalitis kills about 3 people a year. Between 1964 and 2004 there were 60 cases in Florida with Georgia and Massachusetts tied for the dubious distinction of second place with 26 cases.  The average annual number of reported cases of EEE in people in the entire USA is between 5 and 6. Mortality is in the 30-50% range with most survivors suffering permanent disability. Since 2004 there has been an apparent uptick in reported cases and an increase in mosquitoes trapped with the disease by researchers. Normally the disease goes through peaks and valleys in a three year cycle, but that seems to be changing. The most likely culprit (cover your ears and eyes, Republicans) is global warming extending the mosquito season.

The good news, I suppose, is that you can be completely stupid and take no precautions and still be more than likely to escape the disease. The bad news is the disease is so rare and so deadly that it is unlikely there are people walking around with antigens from a mild undetected case as there are with West Nile. Even if you’ve lived in the swampland of Easton all your life, you don’t have immunity to triple E.

Murderous Bambi (I knew that hunter killing his mom was a bad idea) doesn’t cause widespread panic like triple E. Everyone hates mosquitoes including environmentalists who understand their role in the food chain. EEE and mosquitoes are such insidious threats that they easily induce fear. However, if you do a risk/benefit analysis shouldn’t we be shooting deer or banning cars rather than spending money fighting triple E?

There’s no good answer to that question. The family of the Raynham man who died want aerial spraying, but the state argues that the criteria for aerial spraying has not been met. One death of a person in a particularly susceptible category isn’t enough when virus concentrations in trapped mosquitoes and the number of pools with infected bugs remain below a certain level. Aerial spraying is expensive and only offers a temporary threat reduction. You could still get EEE from a mosquito that wasn’t killed (knowing you, dear reader, you’d stop taking precautions!) and even the mildest pesticide has some unwanted environmental side effects for humans and other animals.

That being said, I don’t see the harm in doing a limited ground spray around the periphery of athletic fields. A mix of a relatively safe adult pesticide with a larvacide coupled with the usual change in time for sporting events would go far in alleviating the worry that parents have. Ironically, it’s probably the spectators at athletic events that are most at risk than the participants.

I know covering myself head to foot in Off did not prevent me from getting bitten at the TPC last week. Spraying 18 holes on a golf course was probably unrealistic and DEET did work pretty well while on the course. However, spraying the edge of the cart yard, an acre area tucked into swampy land, would have done a lot to cut down on mosquito bites for our volunteers and the worry that I have about being the unlucky lottery winner receiving triple E as my prize.

So, two cheers for a limited and thoughtful application of the safest spray and don’t forget the other precautions as well. Here’s a suggestion that no one speaks about: have the state spend money to fund research to find a vaccine that is safe for humans. Such a vaccine already exists for horses-our little guys are safe at Sheep Pasture. I suppose we’d discover that more people would die from a large scale vaccination program than would ever die from triple E, but we wouldn’t know until we’ve tried to develop a vaccine. Millions of people might die in a flu epidemic justifying a few deaths from bad reactions to the vaccine, but if more than one person a year died from the triple E vaccine, it wouldn’t be worth it. Sometimes you just can’t beat Mother Nature!

Phenology

The force that through the green fuse drives the flower
Drives my green age; that blasts the roots of trees
Is my destroyer.
And I am dumb to tell the crooked rose
My youth is bent by the same wintry fever.

The sun is the force that drives all in its complex dance through the year. The green fuse traps the sun's energy to produce the flower. The sun's energy creates the weather from a local breeze to a full blown hurricane that blasts the root. Phenology "is the study of periodic plant and animal life cycle events and how these are influenced by seasonal and interannual variations in climate." Phenology attempts to transcribe the music of the sun's dance into something we can understand. If we can't tell the rose about it, we can use this transcription as stewards of the earth.

In a world where genetics and biochemistry get all the headlines, phenology may be the most important biological science of all. How do we translate the sun's story into something we can understand? One way is to simply measure the amount of light on a patch of ground and record what happens there. More useful is the concept of growing degree days. Plant growth around here is thought to start somewhere between 45 and 55 degrees Fahrenheit so 50° has been chosen as a baseline. To calculate GDD you simply take the high and low temperature for the day and average it. If the high was 80° and the low was 60° then the average for the day was 70°. Subtract 50 from the average, and you get 20 Growing Degree Days for that date. Total the GDD's then match the number with events like bud opening or full flowering of a specific plant, and soon you have a record of how the sun's energy effects plant life. You can then expand out to match the lifestyles of the bugs that eat the plants, and the animals that eat the bugs. While it's fun to play Carnac the Magician and predict when lilacs will bloom in your neighbor's backyard, the real use of this method is in integrated pest management (IPM) systems. IPM attempts to cut down on pesticide use and use the mildest possible pesticides, by striking at a pest at its weakest moment. Using phenology you can predict the best time to spray your fruit trees to kill gypsy moth caterpillars before they do extensive damage.

Lilacs have bloomed in doorways long before Walt Whitman wrote about them, and dates of bloom were recorded in farmer's diaries. Collect this data and you can see how our irresponsible acts have changed the music of the solar dance. Birds can't count GDD, but the ones that showed up when the total GDD had their prey species at a maximum survived better than those that didn't so over generations average arrival dates were keyed to average GDD. Change the insect maxima by warming the planet and you have added dissonance to the dance of life that can lead to species extinction.

All this is on my mind today as I meet with an intern from Stonehill who will begin to design a floral calendar for us. It's a first step towards real phenology. Thanks again to Ali and Caitlyn who put me on this path many years ago.