Sleeping trees and spring buds

Spring where I live means muddy trails, gray skies, spring snowstorms and (maybe) a few patches of green grass. It also means tree buds, which caught my attention this year. 

Except, in an effort to learn about tree buds, I found out that the buds have actually been around since the fall, when trees have their last big hurrah of growth and prepare for winter. A good reminder for me that sometimes I only notice what I'm looking for.

The whole experience made me wonder how trees can survive winter: sub-zero temperatures, feet of snow, blizzard conditions, with no warm cave or burrow to escape to.

It turns out trees actually enter into a dormant period over winter. Before winter, they make a growth regulator called abscisic acid (ABA) that halts their growth. Some trees dehydrate their cells, pushing water out of the cell and into the spaces between: there, it can freeze without damaging the cell. Other trees beef up the number of minerals, hormones and other solutes in their cells, lowering the freezing point to prevent freezing. That still isn't always enough, as evidenced by trees that crack or "explode" in frigid temperatures. But those efforts get most trees through the long, cold winter months.

Now back to the tree buds. Cut one open, and you'll see tiny leaves, ready to grow as soon as days lengthen and temperatures warm. 

I love that, how a bud contains everything needed for broad, green leaves, just waiting for conditions to be right. And it reminds me of how writing sometimes feels. Like something is there under the surface, not quite ready to appear. Creativity, like creation, is cyclical. Periods of intense growth and productivity are followed by periods of... nothing.

In writing, I love the first draft part the most, when thousands of words are hammered out and cloudy ideas slowly take shape. Revision is harder for me (though sticker charts help). But the hardest is when I have no writing to do. My creativity seems spent and no new ideas are prodding me on. Books are out to editors, waiting for revisions to return. And I muddle through the days, thankful for my part-time jobs, wondering whether I'll ever write another creative word again.

That's when I need to remember that there's a rhythm to creating. There are seasons - winters followed by springs, ups followed by downs. Even trees rest through winter. And maybe those dismally unproductive periods are actually necessary to prepare for the next spurt of growth. After all, the buds of the next project are likely there, just waiting for spring.

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Images from Pixabay/Creative Commons

Goodbye winter (and notes on duck feet)

Days are longer, the sun is brighter and the snow is slowly melting away. But I can't help remembering how a few weeks ago, on a bleak, frigid February afternoon, I watched a group of ducks paddling along the icy river through town.

The ducks were surrounded by snowy banks and sections of thick ice. And as my own breath came out in crystalline puffs, I wondered how they stayed warm. I wasn't worried about their bodies - yes, the air was frigid, but they have down coats for that. I was more curious about their thinly webbed feet that were submerged in the icy water. 

After a bit of research, here's what I learned.

Ducks have a counter-current heat exchange system: the warm oxygenated blood flowing to their feet passes close by the cold, waste-carrying blood returning to the heart. It's a finely webbed system of arteries and veins that allows the birds to efficiently recapture heat. Since the blood in their feet is already cooler, they don't lose as much heat to cold water. All to say they're not wasting too much energy keeping their feet warm.

But their feet are still chilly: the blood that circulates through is just warm enough to prevent frostbite. And that's surprisingly okay with these birds. Their legs and feet are mostly free of soft tissue. Even the muscles that operate the foot are higher up in the leg, connected to the foot bones by long tendons. So their feet don't need much warm blood. And if they get too chilled, the ducks can pulse extra blood to the foot through valves in leg arteries, providing the needed warmth and preventing frostbite.

Believe it or not, this whole system is also helpful in warm weather. Birds can forage in water hotter than their body temperature as the counter-current exchange keeps their feet cool. This also explains why the Great Flamingo, which has very complicated branching in its arteries and veins, stands on one foot: it's limiting its exposure to heat through its feet. This same system is found in the flippers of whales and sea turtles, as well as some reptiles. 

So the next time you stand at an icy pond and watch ducks paddling along, there's no need to cringe and shiver and worry why those little feet don't turn into icicles. Instead, you can tuck your hands in your pockets, watch your breath cloud in front of you, and marvel once again at intricacy of nature.

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photos from Creative Commons/Pixabay