Photosynthesis in Winter

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(in the Bosque…note the distinct greenish – yellow color)

 

I began to get very interested in the possibility of the bark of some trees photosynthesizing in winter as a result of my predawn meanderings in the Bosque. I noticed, for example, the pale skin of Mexican Privet and the young branches of Cottonwood trees. Both had a pale greenish tinge. I also recalled the Aspen and Poplars on my land in Maine that also had greenish bark.

 

When I was researching for an article on Aspens I learned that the willow family that included Aspens, Cottonwoods, and Poplars as well as our Coyote Willows did indeed photosynthesize all winter long as long as temperatures stayed above freezing. If sunlight warms bark on the south – and southwest – facing sides of trunks and branches, it makes it possible for bark to photosynthesize even when air temperatures are below freezing.

 

Energy produced by bark photosynthesis is thought to support regular cell maintenance in the trunk and branches and can help trees recover from defoliation due to insects, storms, or severe drought.

 

I keep a sharp eye on the Coyote Willows because I don’t want to miss the changes that are subtle; they are already starting to turn. Anthocyanins and carotenoids are plant pigments that produce the red, brown and purple colors in willow stems while carotenoids produce yellow and orange hues. Both anthocyanins and carotenoids protect photosynthetic pathways from being damaged by New Mexico’s intense spring light before the narrow leaves appear. My observations suggest that the only time the willows approach dormancy is during December and January (at least this year).

 

Because we have spent most of the winter with above freezing conditions this may have been a particularly good year to notice subtle changes in young bark. It turns out that Birch and Beech, two northern trees, are adept at this process as well. I only recently discovered that some northern deciduous trees continue to photosynthesize even under the snow! There is filtered light, beneath the snow – pack. And plants are able to harvest that light once temperatures get above freezing, most notably in wetlands – good examples are pitcher plants and cranberries. And, not surprisingly, low growing alpine plants, also avail themselves of this strategy in the harsh alpine zone, where the growing season is so short.

 

We all know that plants and trees use their leaves to convert sunlight into sugar, or carbohydrates during the warmer months, and some folks are aware that evergreens continue to photosynthesize all winter as long as the temperatures are above freezing; one reason we continue to water our evergreens at regular intervals in New Mexico.

 

Although I don’t have adequate research available to support my hypotheses I suspect that many trees and bushes with thin bark in our areas take advantage of this phenomenon. Certainly Chamisa must; their lime green bouquets are stunningly beautiful by February. I also suspect that my two pear trees may be doing the same thing. In just the past three weeks the bark has lightened to a pearly eggshell. Unfortunately, for young trees and bushes this tender sweet bark with cambium beneath provides a sugary treat for hungry rodents.

 

Many people don’t know that extreme temperatures of 100 degrees or more will stop photosynthesis completely in trees, and around here summer temperatures hover well above the 100’s in the sun. Thus, beginning the photosynthetic process early in the year has definite survival value for our trees and bushes especially as the Southwest heats up. Did you know that according to NOAA, 2019 was the hottest year in recorded history?

 

Another aspect worth mentioning is that early photosynthesis helps with buds that are getting ready to swell. I am fortunate to live near a cottonwood bowery so I can watch those photosynthesizing buds and twigs every single day, and they have definitely begun to become engorged. But even in the Northeast the buds are visible. Those of red maples are swelling, weeping willow twigs develop a yellow tinge, as do the pussy willows. There is a narrow window to spot them during the time between snow – melt and when the buds burst into flowers and leaves. Scientists call that period the “vernal window.”

 

According to Rebecca Sanders-Demott, a research scientist at UNH, the length of time between melt and blooming can have implications for how much carbon dioxide goes into or out of a tree’s system on an annual basis. Demott been researching this vernal window. If snow melt occurs very early in mid-February for example, we know that leaf out won’t happen until early May so there is an extended “vernal window”.

 

That extended window has different effects on different species, but scientists are in agreement that changes to the window impact how much photosynthesis occurs during the rest of the season.

 

In New Mexico the vernal window is a long one that helps the trees and bushes to maximize photosynthesizing before summer heat strikes its lethal blow.

 

Photosynthesizing tissue, whether buds, the year’s new shoots, or tasty branches and saplings are a welcome arrival for animals in any region this time of year.

 

Yesterday I had a couple of very unwelcome cows who were just about to devour my crocus, planted only inches from the house; one had already begun to feast on my favorite juniper when my dogs went berserk as did their mother. As a self-responsible animal ‘owner’ I balk when others allow their animals to trespass illegally. At the very least cow owners could feed their livestock so they stay home.

 

Just for fun I am experimenting with willow twigs, but the wily rabbits are onto me; they systematically demolished my first experiment with ease. Undeterred, I have devised a different method to foil them, but I carry grave doubts of its success because ‎Lagomorphs and other wild animals are much smarter than me!

Winter River Reflection – 2019

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We are approaching the end of January here in Northern New Mexico and already the light is becoming more fierce, but the nights are still long, the blood moon has passed, and clusters of stars are strung like pearls into patterns that speak to ancient stories, so this precious time to reflect and dream is very much with me. Winter brings a sense of peace unlike any other.

 

This year it has also brought us a reprieve from drought. This morning a thin layer of snow once again coats the grasses while birds flock to my feeder in record numbers. Although each layer of snow doesn’t amount to much more than a tenth of an inch of rain, it is still something. Last week we even had real puddles of standing water, and slippery mud that oozed in places when the sun warmed the ground.

 

Coming from the North Country I have never been able to appreciate mud with the kind of enthusiasm I have for it here. Mud means moisture, and water is life and here in the high desert rain and snow may bring sage green scrub back to life if we continue this trend…

 

Reprieve from drought is a form of Grace.

 

In the distance the mountains wear white tufted caps – Perhaps this year Red Willow River will once again overflow her banks serenading us with songs as snow melt sings to disappearing stones.

 

Is it too much to dream that frogs will come, rising up from moist red ground to breed?

 

As I kneel before the wood stove kindling my daily fire, I am keenly aware of the deep gratitude I feel for the gift of life and for each drop of water even when these aging bones ache in dampened air.

 

I wonder where my afternoon walk will take me? No matter where I go I always end up back at the river’s edge listening to water on stone while scrying the sky for the Sandhill cranes. The river has always been my lover, long before I arrived here… A tangle of blushing willows greets me as I bow low to walk through their arching branches into the old overgrown field, lumpy with gopher mounds.

 

This winter I have started to cook again with joyful child-like abandon. The intoxicating scent of yeasty bread no longer brings a wave of grief for lost children but simple joy in the rising…some say that cooking is a form of transformation. So it may be for me.

 

Moving into “old age”, the years of the crone, my elder years snaps the constricting steel ties that threatened to suffocate my body, and shredded the caul of the “mother hood” – an unwelcome veil I wore for too many years, one that was too heavy with grief; grief that eventually came to threaten my life. Now, because of the shadowy presence of an Old Woman who comes to me as an Owl, a star child begins to shine.

 

Bear’s Day is approaching, that time of the year when the wheel turns once again towards the coming light, and Brigid’s Crown of Fire speaks to new life bubbling from beneath the ground. Already bulbs are stirring from deep sleep, tree roots are absorbing precious water as they begin a new growth phase, and black bear cubs are being birthed by attentive wild mothers…

 

Soon the Sandhill cranes will be migrating North as will the flock of golden evening grosbeaks that have taken over my porch, all in search of summer breeding grounds.

 

As I approach Bear’s Day, and the Feast of “First Light” I feel ambivalence, for each lengthening day brings me closer to the time of my own birthing into spring, and the necessary migration I must make to go North. It is hard to be caught between worlds. I have a homeplace here in the South and another far North.

 

I must place my trust in myself, and the Old Woman. Bird-like, I will migrate too, before spring light births a bitter orange sun, fierce and deadly west wind, and a wall of intolerable heat.

Winter Birds

IMG_2068Every afternoon I sit down at my table, binoculars in hand to breathe in the peace of the twilight hours and to commune with the birds who are gathering for their evening meal. The mourning doves have already sailed into the open feeders that hang from a pole under the protection of the field pine overhead, scratching seed onto the ground with abandon. I draw in my breath sharply if a female cardinal dressed in an olive coat flies down to peck the seed below because her visits to the feeders are sparse. A few blue – jays may still be about although the heaviest concentration of jays occurs when I first put food out in the morning. Their raucous screams “here she comes” alert the neighborhood that food is on the way. Juncos are around all day long, feeding on the ground. The goldfinches are morning visitors that retire by mid afternoon. Swarms of them flit back and forth like bees from one feeder to the next during the morning. Purple finches also gravitate to the open feeders on the pole and use any of the three that are vacant usually during most of the day. Chickadees and nuthatches are out and about from dawn to dusk, delicately picking out one seed, flying away, and returning for another in a few seconds. Every time I think the robins have left another one appears. Fortunately I still have a few small crabapples left on my trees for robins and the two grouse that come and go. Another bird that has surprised me this year is the white throated sparrow. A whole bevy left in late November and four appeared here in January morning and have been with me ever since. The first day they arrived they were on the ground searching for seed until nightfall.Occasionally I have a few other sparrows visit for a day or two. When I am home I try to keep track of who is coming or going during the day and note the distinct feeding patterns of different species. There is one small feeder hanging from an apple tree that I have to fill twice a day because it is the chickadees’ favorite, although these little birds are democratic in their leanings and visit all feeders at some point. Hairy and downy woodpeckers are early risers and are always announcing their presence with a loud staccato like chirp as they land on the suet, or the open feeder. They have a tendency to avoid crowds and usually retire around three in the afternoon. But most fascinating is the way they climb down the pines to snack in the protected area where I scatter a small amount of seed on the ground for the cardinals (Small is the operative word here because ground feeding brings in the squirrels within minutes). Sometimes the pileated woodpecker who resembles a prehistoric raptor makes an appearance around mid -day landing on a crabapple out front where I hang suet but he rarely stays. He also announces his presence with an otherworldly laugh. The two kinds of nuthatches also climb down the pines to feast on the ground if they find food there but they use the open feeders too.

Every year I have tufted titmice. This year I have two pairs but I have never had a titmouse sing during the winter like one of these little males does. He has three songs, one of which he begins to sing early in the morning; it is composed of three delicate whistles. He also has a shorter version of the same theme that he sometimes uses during the day. Another variation less frequently heard, perhaps my favorite, is his descending double whistle. I have started to call to him whenever I am outside and if he is around he answers me with the three whistles call. When I thank him for the concert he always responds with another song! Most birds are notoriously quiet during the winter months and so I was delighted and mystified by this little fellow’s proclivity for singing and was surprised to discover that titmice do apparently sing during winter thaws. So far this winter the mild temperatures might be the reason this little fellow is so vocal. More interesting is that there are at least eight distinct calls that have been identified as variations on three basic themes. According to the literature the musical whistle I hear most of the day and the one this little bird sings to me is considered to be a morning call. Not so here. This little fellow has been singing that particular song all day throughout the month of December and into January. With colder temperatures and snow on the way, I wonder if he will continue to serenade me? The soft gray blue coat, tufted cap and brilliant coal black eyes of this small bird is so appealing as he flits back and forth to the feeders, rustles through leaves in search of insects, or hangs upside down on twigs but it is his songs that so endear him to me. I rarely see him or his extended family after mid-afternoon.

The birds that draw me into late afternoon communion are the cardinals. Everyone I suppose has a favorite bird and the cardinal is mine. For a while last summer the Indigo Bunting captured my heart but the cardinals eventually won out. I have reached the conclusion that there is something about these birds that embodies the spirit of Nature as divine. They are my wild “Spirit Birds.” Somewhat reclusive by nature the cardinals are not birds that flit back and forth to feeders all day long. They come only at certain times and are very particular about where they eat. Although somewhat sociable with their own kind, they dislike hoards of other birds and avoid feeding with them. I rarely see them at the open feeders on the pole except at dawn. Cardinals are ground feeders that prefer the protection of trees; here they gather under the pines outside my kitchen window just before dusk during this darkest time of the year. I find myself scanning the pines for the first sight of my beloved “Red Bird” one male that has an ethereal bluish cast to his wings that is noticeable only when he is on the ground. The rest of the bird is fiery crimson. Once he makes his first appearance I feel palpable relief (A number of years ago I lost a male fledgling to a cat and a couple of adult male cardinals to unknown causes and apparently have never recovered from the losses). This is when I fall into a meditative state, hyper –alert but sinking into the comfort of my body as I move into another dimension. The shift is so subtle that I barely notice the transition until I realize that I have lost time, and now it is too dark to see the birds! In the interim I have been watching my Redbird and his ladies fly in to eat their favorite sunflower seeds, disappearing, and returning again and again until dark. Because this has been an unusually mild fall and winter so far I will be curious to see what happens… Soon the world will turn white again, and I am perched like one of my birds at the edge of this turning because although the sun is journeying northward, the coldest winter days are upon us…