Fixit: Reason for prolific seed production is unclear

Q Why are there so many helicopter seeds on soft maple trees this year?

A The reason is unclear, said Mary Meyer, professor at the University of Minnesota's Landscape Arboretum who also has noticed prolific seed production this year on elm trees.

Sometimes trees will produce a lot of seed when under stress or dying, in an effort to get their genes into the next generation, she said.

But good environmental conditions -- such as the moist and mild weather we've had this spring -- also favor seed production, Meyer said. If that's the case, and it's a good year for seed production for all trees, oak trees will produce lots of acorns this fall.

Both scenarios could be in play this year, with one tree under stress and another responding to environmental conditions.

Prolific seed production is a good thing from the plant's point of view: They are going to have offspring. And it's good for wildlife, too. Lots of seeds means lots of food for birds, squirrels and other wildlife that feed on them.

More on water heaters Reader Paul Thomas of Coon Rapids shared some thoughts about a recent column on water heater efficiency.

"You did not mention the difference in efficiency between gas and electric water heaters.

"A gas water heater has to vent the combustion products to the outdoors, so it has a hollow chamber running up through it connected to a vent pipe, and it loses some of the heat from the burning gas, and some additional heat from the hot water itself, when the flame is off. The estimate of 63 percent efficiency is probably fair.

"An electric water heater converts virtually all of the electric energy to heat in the water, but the generation of electricity from the burning of fossil fuel is only about 33 percent efficient. The power plant has to burn about 3,000 BTUs of natural gas or coal for every 1,000 BTUs of heat delivered to the water heater. So from the standpoint of overall fuel consumption and greenhouse gas emissions, the electric water heater is very wasteful."

Send your questions to Fixit in care of the Star Tribune, 425 Portland Av. S., Minneapolis, MN 55488, or call 612-673-7032, or e-mail fixit@startribune.com. Past columns are available at www.startribune.com/fixit. Sorry, Fixit cannot supply individual replies. Fixit appears daily in Source except on Friday.