by Carl Strang
The weather has become more seasonable of late, but plants continue to respond to the early warming of the soil. Last week brought the first winter cress flowers of the season.
The April 7 flowering date compares to 29 April last year, 13 April in 2010 and 27 April in 2009.
Oaks have broken their buds and are on the verge of flowering, as well.
White oaks usually are relatively late to open their leaves compared to other trees.
I would like to think that this will impede development of gypsy moth caterpillars. Those invasive insects hatch from egg masses which mostly are well above the ground, and it would be nice if that removal from the warm soil delayed their appearance until after the oak leaves have established some chemical protection. More likely, though, is that the caterpillars will be equally early and there will be no advantage to the trees. The coincidental timing of oak bud break and gypsy moth egg hatch is what makes oaks as a group more susceptible to defoliation by the caterpillars.
Tony William Powell said,
April 10, 2012 at 10:09 am
Hi Carl,
Amongst other things, I have just posted about our bud bursting European Oaks over here in the United Kingdom.
I truly do love spring and all that it brings.
Best Wishes
Tony Powell
intergenerational said,
April 10, 2012 at 3:43 pm
What synchronizes oaks and moths-is it temperature of the environment or other?
Like your posts!
natureinquiries said,
April 11, 2012 at 5:47 am
I believe it is temperature, the tree responding to soil temperature and the moth eggs to air temperature. We have relatively few gypsy moths in our area right now, which is good, but I have no egg masses to check for their timing of hatch.
jomegat said,
April 10, 2012 at 9:01 pm
Are those oak blossoms? I have looked for oaks to flower, but have never been able to tell that they have – all my oaks are pretty tall, and I have to observe any flowering activity from 80 feet away.
natureinquiries said,
April 11, 2012 at 5:50 am
Those are strings of flower buds, on the verge of opening. They won’t be much to look at when they do. Being wind pollinated, the oak flowers are simple releasers of oak pollen or receptacles for it.
Testing the Birds and Buckthorn Hypothesis « Nature Inquiries said,
May 10, 2012 at 6:00 am
[...] insects, and also not providing the shelter that the birds need on their daytime migratory stops. As I pointed out a few weeks ago, like our flowering phenology, the oaks broke buds a few weeks early this year. Remember this [...]