The Endearing Phoebe

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The Phoebe that helped me solve a mystery

 

Last year when I returned from New Mexico I found an Eastern Phoebe’s nest under the eaves above my front door. I witnessed the three nestlings mature with deep pleasure, happy because the phoebes have only nested on the house once before, though this little valley has been home to these endearing birds ever since I built the house. Every year I watch them hunt from the wild apple tree with its golden apples that spans the entire southern wall of the house and overlooks the brook. In fact I am watching a phoebe hunt as I write these words. In years past I always looked forward to their arrival in the early spring after a long Maine winter.

This spring the phoebes chose another nest site, probably one of their old ones, perhaps because last year I removed the dormer that protected their nest; I can’t be sure.

Two days ago I watched a phoebe fly from a nearby crabapple towards the very spot above the door where the birds had their nest last year. I was baffled by this strange behavior and when I investigated I found the answer. Phoebe was hunting hungry mosquitos – there was a whole cloud of these little monsters that had convened there apparently while waiting for me to open the door! Insects are smart, and this convocation is a perfect example of insect brilliance. No wonder the bugs were getting in. I thanked my little friend for his help before rubbing peppermint oil on the wood to discourage the mosquitos, who then vacated the area. Because I am repeating this application the phoebes are no longer hunting around the front door, but have returned to their previous hunting ground, the apple tree. When I posted a couple of phoebe pictures my friend Carol Bondy mentioned that she had some nesting on their house. I hope at some point to see some of her pictures.

In Abiquiu I hear phoebes in the gracious Cottonwoods during the winter but I rarely see them and whenever I do it is always just a glimpse of a wobbling tail or bobbing. After hearing about Carol’s experience it suddenly occurred to me that these New Mexico phoebes might be a different species. And of course they are. The reason I had never thought about this issue before is because their calls sound alike to me although the literature states that there are distinct differences. I was baffled by this apparent inconsistency. When I actually listened to the two species singing I noted that The Says phoebe has a shorter call or peep, though it sounds similar to the call of the Eastern phoebe, a sound I have heard all my life. At least one of the sources I consulted said that the ranges of these two species can overlap Is it possible that both species inhabit the Abiquiu area? If they do I would love to know.

The primary difference between the Eastern phoebe and the Says Phoebe of New Mexico is that the former have a pale belly as opposed to the cinnamon – washed belly belonging to the latter.

Both species of flycatchers migrate north in the early spring and are noted for being early arrivals. Unlike many other birds both species reuse nests. With that much said it is also true that Phoebes that are breeding in the Southwest do not migrate and are present year round.

In the east the phoebes place their mud-and-grass nests in protected places like houses, barns, under bridges or around here in nests placed close to the brook (the one on the side of the cabin was made with a lot of moss). They gravitate to protected woodlands.

The Says phoebe will also nest on houses and buildings but otherwise “is an open country bird”. The literature says these phoebes perch on fence posts and pasture wire but I have not seen this behavior although both wire and fence posts border the casita on the riverside. It seems to me that phoebes in Abiquiu would be drawn to the Bosque because this is where there are more insects to eat. Out of season they are fond of berries. They are supposed to lay two clutches of two to six eggs. Here, the family that nested under the eaves only raised one.

Both species seem to tolerate and even befriend humans who pay attention to them. This has been my personal experience with the phoebes that hunt from the wild apple tree. They watch me through the window with beaded eyes while bobbing up and down and wagging their tail feathers in that characteristic phoebe way. They do not fly away, even when I approach them; they respond to the sound of my voice with apparent interest.

Happily, according to Audubon both species appear to be maintaining a stable population.

The Eastern Phoebe became the first banded bird in North America. John James Audubon attached silvered thread to an Eastern phoebe’s leg to track its return in successive years.

The Eastern Phoebe is a loner, rarely coming in contact with other phoebes. Even members of a mated pair do not spend much time together. They may roost together early in pair formation, but even during egg laying the female frequently chases the male away from her. I didn’t find similar information about the Says phoebe but my guess is that the two behave in much the same way. I never glimpsed more than one at a time in Abiquiu.

Say’s Phoebes have been in the U.S. since the late Pleistocene. Paleontologists discovered Say’s Phoebe fossils in Arizona, California, New Mexico, and Texas dating back to about 400,000 years ago.

The Say’s Phoebe also breeds farther north than any other flycatcher and is seemingly limited only by the lack of nest sites. Its breeding range extends from central Mexico all the way to the arctic tundra.

I know from personal experience that befriending these little birds is a worthwhile endeavor providing the viewer with hours of entertainment – sometimes at the expense of work that has to be done! The little fellow outside my window keeps interrupting my train of thought with his aerial dives.

Bluebird Spring

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When I arrived home in Maine seven weeks ago my friend Kathy who lives down the road already had eastern bluebirds coming to her feeders. Because I think of bluebirds as being insectivores (although they love berries too) their early arrival seemed unusual to me until I did a little research and discovered that bluebirds as a species are expanding their winter range as Climate Change continues to push them northward. I didn’t know that some have been living year round in Massachusetts for some time.

 

Most Eastern bluebirds who breed in northern climates do migrate, gathering in large numbers during November to fly south. In March, April, and May they move north to summer breeding grounds. In Florida where there is a stable population the bluebird may breed as early as January. Putting up nest boxes for bluebirds is helpful because these birds have lost so much habitat. Around my house here in Maine all snags have been left intact, as have all the trees so I have many natural cavities for all kinds of birds to nest in. But except for my field I have little open space. This year a friend of mine is making me a nest box, so perhaps I can attract a bluebird couple of my own.

 

Wherever these birds breed, the male initiates courtship often providing his mate with a tasty morsel or two while delicately fluttering his wings. The female lays four to six eggs that are a stunning shade of blue. Here at least, two broods are raised during one season. While the female sits on the second set of eggs, the male takes charge of the nestlings.

Caterpillars, spiders, and insects of various kinds provide the young with protein. Newly ploughed fields are an excellent source of insects and grubs. As previously mentioned bluebirds are also fond of berries and other ripe fruits. During the late summer and fall, bluebirds pounce on grasshoppers from the tops of mullein, an herb that is so common in natural fields. In the west hundreds of bluebirds might gather to feed on juniper berries. My guess is that they could do the same around here.

 

When I glimpsed bluebirds perched on my telephone wire a couple of weeks ago I got a chance to watch them through binoculars. I noted that the subtle coloring of the females varied as did the vibrant blue of the males.

 

I was also struck by how similar these eastern bluebirds were to those western bluebirds that I had glimpsed during the spring and early fall months in Abiquiu. I knew that I would probably not be able to distinguish one from the other unless I could identify the blue patch on the western male’s belly; the eastern bluebird has more white. Another identifying marker is that male western bluebirds have blue throats, while the male eastern bluebirds have orange or rust colored throats. I also didn’t know that the two species were so closely related that they interbred, or that both eastern and western bluebirds nested in the Rio Grande Bosque.

 

Around the casita I watched what I thought were western bluebirds (!) perch on the fence wire overlooking the field. When spotting tasty prey they sometimes took insects from the air; occasionally, they flew to the ground. By late fall these birds were gone.

 

Both eastern and western bluebirds prefer semi –open terrain; orchards, farms and ranches are excellent places because they are often surrounded by pine, oak, ponds for cattle, and streamside groves. Both eastern and western bluebirds tend to avoid hot dry regions during the summer but in the west they will nest in pinyon – juniper forests.

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(Fledglings)

 

Overall, the eastern bluebird is also in decline for the usual reasons. In recent decades, the western bluebird numbers have fallen dramatically over much of their range. The use of pesticides and controlled and uncontrolled burns destroy masses of habitat and are creating havoc for all southwestern bird species. Because western bluebirds have also become relatively common Bosque breeders over the past two or three years, it is more important than ever to protect our precious Rio Grande Bosque.

 

Bluebirds are important in the traditions of many Native American cultures. In particular, Bluebird is a symbol of spring. In Iroquois mythology, it is the singing of the bluebird that drives away winter. Bluebirds are also associated with the wind by the Cherokees, and were believed to predict or even control the weather. The Navajo and Pueblo tribes associate bluebirds with the sun; in some Pueblo tribes, Bluebird is identified as the son of the Sun. The Hopi see the bluebird as a directional guardian, associated with the west.

 

I close this narrative with a personal memory…

 

When I was a little girl I would sit on my grandfather’s desk, (the same one that I write on now) and look out the east window to watch the bluebirds enter and leave their nest boxes. My grandfather had ten homemade boxes positioned across the large and open field. Each year the bluebirds returned and my grandmother, my little brother, and I loved to see the fledglings leave the nests for the first time. I was always afraid the little ones would fall and my grandmother would have to remind me that I had never seen one get hurt –not ever.

 

 

 

May the bluebirds live on!

 

 

 

 

The Quackers

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( I chose this picture rather than using one of my own because it highlights the male’s emerald green head and the blue on its feathers – gorgeous duck!)

 

A number of years ago I decided to raise some baby Mallards. As a child I used to feed and make friends with them, even as a toddler I was told. Because I live so close to North Pond I decided to raise some Mallards and release them on the lake, although I had never seen them here and wondered why. After doing some preliminary research I learned that this area was a breeding area for wild Mallards, so I figured that I had nothing to lose.

 

What an adventure! The “quackers” were characters. My dog adored them and they seemed equally fascinated with her because whenever Star visited with them they would waddle over to quack excitedly at her when she pawed their cage. I came to love them too, and although they made a horrible mess I loved the quackers enthusiastic morning greeting. When the day came to release them I felt sad.

 

By this time I had spent a lot of time in my kayak looking for a safe haven for the youngsters. I created a nest at the end of a peninsula, and left them there on North Pond. I saw the quackers occasionally during that summer while kayaking but when they migrated in the fall they didn’t return… I believed my experiment to re- introduce them had failed.

 

About a week before leaving Abiquiu I spied a Mallard couple on the river a few times. Much to my surprise, when I returned to Maine the first of April, I also spotted another Mallard couple on the North Pond – the first Mallards I had ever seen here since I let the quackers go. Was it possible that this couple had returned to breed?

 

When I researched this possibility I learned that Mallards choose new mating partners each fall. They stay together throughout the winter and once the mating season ends the male abandons the female to raise her family (up to13 chicks) alone. The female returns to her original waters to breed, so it was conceivable, that the female was the original “quacker” that I had raised.

 

All the breeds of ducks that are common today can trace their origins to the wild Mallard except the Muscovy who roosts in trees in South America. No one knows for certain when Mallards were first domesticated, but there is some evidence to suggest that the Egyptians sacrificed ducks and also bred them for food.

 

Breeding Mallards nest in the North Country and in Canada and Alaska. Females will build a nest out of breast feathers and twigs near a body of water. She lays a clutch of eggs and incubates them for a month. Once the ducklings hatch, they are immediately taken to water for safety. The ducklings will follow their mother for the next 50 to 60 days, maturing and developing their ability to fly. The ducks can reach breeding age after a year. Mallards frequently interbreed with Black Ducks and the Northern Pintail.

 

There are four major flyways that Mallards use. Migrating Mallards in Abiquiu use the Pacific Flyway; In Maine they use the Atlantic flyway. Non breeding Mallards inhabit most of the country, and some live year round in Florida and other southern most states including southern New Mexico. Many are considered pests and millions of these birds are killed each fall by hunters.

 

Mallards are the latest fall migrants and fly in a V-formation in order to have the lead bird break the headwinds and lower the resistance for those that follow. They migrate at night and although theories abound, no one knows how they manage to navigate such distances. Mallards can travel 800 miles in one day. They are excellent endurance fliers, sustaining speeds of up to 40 miles per hour. They usually fly at altitudes between 400 to 2,000 feet, but have been spotted much higher and have even gotten into crashes with commercial airliners above 20,000 feet.

 

Mallard ducks can be found in the Northern Hemisphere throughout Europe, Asia, and North America. Most Mallard ducks are migratory birds, flying south to temperate climates during the winter, and northwards in the summer to nesting grounds. Mallards prefer wetlands near water sources with an abundant supply of food and cover. They can be found in many types of habitats throughout the country including lakes, rivers, streams, small ponds, swamps, marshlands, and water reservoirs.

Their diet consists of aquatic vegetation, insects, worms, and more recently grain crops like wheat and corn. They dip their heads under the water and forage for plants on the bottom. This “dabbling” is the feeding technique the ducks prefer and execute most often. When visiting the Bosque del Apache I was delighted to see so many Mallards. The heads of the males are fashioned out of shimmering emeralds, and to my mind are astonishingly beautiful to behold.

Mallards are also the most heavily hunted North American ducks, accounting for about 1 of every 3 ducks shot. This species can also be affected by poor water quality, including mercury, pesticides, and selenium pollution, wetland clearing or drainage, oil spills, etc, etc. They are losing ground. Across the continent, millions of acres of wildlife habitat have been converted to agriculture. Some have adapted and eat harvested rice, corn, wheat, barley, peas, and lentils. I cannot help wondering what agricultural pesticides might be doing to these ancestral ducks.

 

Mallards, like so many other migrating species are migrating later and returning to breeding places earlier than ever before. And perhaps like other migrating birds their patterns are shifting.

 

I am anxious to learn whether the Mallards I saw for a few days were still migrating or if they will spend summer on North Pond.

The Croakers

 

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(Frogs mating – note the one who didn’t make it! Eggs in upper right)

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(Look at those golden eyes!)

 

The most exciting part of arriving home in early April is that signs of spring are everywhere. This is truly the season of new beginnings. I listened for the croaking quacking wood frogs at every ditch, puddle and vernal pool and was rewarded by one croaking male wood frog on April 12th.

Two days later in the same place I discovered one couple mating and laying; a few clumps of jellied eggs were scattered close to the frogs who were still clasped together. The frogs vanished the next day. I realized then that in this place there should have been many couples, not just one…All frogs and toads are the most threatened species on earth, our canaries in the coal mine. They absorb pollutants through their skin – human induced poisoned air, earth, and water. We are currently in the process of losing the species for good.

 

I happily scooped up the newly laid eggs to bring home to scatter in various vernal pools on this property where the have a better chance of surviving, grateful that I had not missed wood frog emergence. Normally they begin to croak before ice –out in late February March (March around here). So I am a bit puzzled by their current behavior.

 

Wood frogs are native to our Boreal forests in Alaska, Canada, and throughout the Northeast. Wood frogs are the only frogs that live north of the Arctic Circle.

 

Wood frogs are omnivorous, and eat a variety of small, forest-floor invertebrates. Adults consume a variety of insects including spiders, beetles and moth larvae. The tadpoles feed on plant detritus, algae (they also like lettuce) and also eat the eggs and larvae of other amphibians.

 

Similar to other northern frogs that enter dormancy close to the surface in soil and/or leaf litter, wood frogs can tolerate the freezing of their blood and other tissues. Urea accumulates in tissues in preparation for over wintering and liver fluid is converted in large quantities to sugars in response to ice formation. Both act to limit the amount of ice that forms and reduces osmotic shrinking of cells.

 

Amazingly, these creatures can survive many freeze/thaw events during winter if no more than about 65% of their total body water freezes.

 

After wood frogs emerge from hibernation they begin a yearly migration to the nearest vernal pool for breeding, starting in late February or March. This species is often described as an explosive, short-term breeder which means that the window for survival is minimal. In this region, breeding often takes place over just a few days. Males search for a mate by hugging other frogs until they find one who is round enough to be carrying eggs. Females lay approximately 1500 – 3000 eggs, often in the deeper sections of the pools. Out of the large amount of eggs deposited only about 4 percent survive. The egg mass retains heat, and those eggs located near the center of the mass have a higher survival rate.

 

Communal egg masses are sometimes attached to vegetation within pools. The ones I have found in ditches are free floating. Eggs will hatch in 4 to 30 days. Temperature is a factor. Around here the eggs I have hatched have become tadpoles in 2 -4 days.

 

In four to sixteen weeks, depending on water and food supply, wood frogs have completed their growth cycle. My tadpoles become frogs during the month of July. Maturity may be reached in one to two years, depending on the sex and the population of frogs. A wood frog’s lifespan in the wild is usually no more than three years.

 

In my eyes the glorious sight of a wood frog (now very rare) is cause for celebration. I used to see a few each summer, but no more. They are found in deciduous, coniferous, and mixed forests; marshes; meadows; and swamps. Most of the time the frog lives close to the ground, hiding under leaves in woodland areas.

 

A wood frog’s most distinct characteristic is the black marking across its eyes, which has been said to resemble a mask. The bodies of wood frogs can be varying shades of brown, red, green, or gray, with females tending to be more brightly colored than males (note picture). These frog hues sound dull but each has an iridescent sheen. Adults can reach about three inches. The ones around here do not.

 

It seems to me that everyone loves to eat wood frogs from eggs through adulthood…Herons maneuver their way into my vernal pools for a snack even in the deep woods! My kingfishers love them. A variety of snakes eat adult wood frogs. These creatures fall prey to snapping turtles, raccoons, skunks coyotes, and foxes. Beetles, turtles and salamanders feast on eggs and tadpoles.

 

In the amphibian world, wood frogs may be the species best able to recognize their family. When many tadpoles are in the same place, siblings seek each other out and group together (my guess is that it is the only species that has been studied). My observations of all frogs confirm that the young like to be close to one another.

 

Wood frogs are found in deciduous, coniferous, and mixed forests; marshes; meadows; and swamps. They spends most of their time on the ground in woody areas except for during mating season when they are breeding.

 

I am anxiously awaiting the birth of these tadpoles hoping that my attempts to scatter the “Croakers” around my property will lengthen the time they remain on Earth.

The Ecology of Bark

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(the wonderfully wrinkled bark of an old Cottonwood tree that I love)

 

Wandering among the trees and bushes in the Bosque each day has peeked my curiosity about bark and it’s less obvious functions.

Some trees like aspen and birch have smooth skin all their lives, others like the Cottonwoods end up with heavily wrinkled bark that sometimes turns reddish with age in the Southwestern sun.

The term “bark” is often used to describe only the corky, visible outer surface of trunks and branches. In botanical terms, though, bark includes the entire, multi-layered shell of a tree that can be detached from the wood -that is, everything outside a thin ring of tissue called the vascular cambium. Cells divide and grow in the cambium layer, producing a ring of wood in the inside and a layer of bark tissue, called the active phloem, on the outside. The phloem transports sugars and nutrients throughout the tree, and is typically hidden from view, beneath the outer bark.

Outside the phloem, trees have three additional bark layers, collectively called the periderm. The first two layers are virtually invisible; the inner layer – the cork skin – usually contains chlorophyll and does some photosynthesizing. The middle, cork cambium layer facilitates cell growth. The third, outer layer is made up of cork cells that die soon after they mature. This cork layer protects the tree from infection, infestation, and drying out. The smooth, unbroken outer bark that all trees start out with is this cork layer.

As a tree grows, its wood thickens and pushes out against the bark that surrounds it. The different ways in which the outer bark adapts to this pressure is what gives each species its distinctive appearance. Some species maintain their original outer layers for their entire lives. In such cases, the outer bark expands to match the growth of the wood beneath it, and it remains unbroken.

However, in other trees pressure from the faster-growing wood soon causes the initial periderm to split as a new layer forms in the inside, usually in overlapping sections that vary in shape, size, and thickness according to species. This process can repeat itself as a tree grows. Alternating layers of old periderm and dead phloem form the thick, craggy, wrinkly outer bark that is found on most mature trees.

In each tree species, the bark’s appearance is determined by the shape of the overlapping sections of periderm, the type of connective tissue, and the rate at which layers of bark break apart.

Thick outer bark is generally a good investment, since it better protects a tree from wounds and provides more thermal protection. The outer bark’s air-filled cells function much like home insulation, keeping the inside warmer or cooler than the outside. Ridges, scales, and vertical strips can dramatically increase the outer surface area and help maintain a more even temperature. Contoured barks also hold moisture, which slows the transfer of heat through the outer bark. I think these characteristics are really easy to see on the trunks of adult cottonwood trees.

Thick bark is especially important for fire protection. Redwoods, for example, have bark that is almost a foot thick making the tree impervious to all but the hottest fires.

Rapid temperature changes can also damage or kill sections of bark. In winter, for example, direct sunlight can warm bark to temperatures much higher than the surrounding air. When temperatures plummet rapidly, cooling bark can crack as it contracts. Extreme temperature changes create havoc.

With all the protective advantages of thick bark, why does the bark of some trees remain thin? Smooth bark is easier for the tree to grow but a major advantage of thin bark is its increased ability to photosynthesize. Scraping away the outer bark on a twig or young branch reveals the thin skin that photosynthesizes in some cases almost as efficiently as the leaves of trees can.

Since thick bark blocks most or all sunlight from reaching the cork skin, photosynthesis levels are usually much higher in species that maintain thin bark on their trunk and branches. 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. Bark photosynthesis works best when leaves do not shade the bark. Even in a seemingly dormant forest if the sun warms the bark it can photosynthesize even when air temperatures are below freezing.

Thin bark also helps thwart mosses, lichens, and algae. Epiphytes can block sunlight preventing efficient photosynthesis. They can also absorb heat, which increases a tree’s risk of damage from temperature changes. Some trees, like paper birch, feature strips of bark that peel away from the trunk and take with them any light-blocking epiphytes that may have become established there. An amazing adaption, that!

Outer bark also protects a tree against intruders. In general, thin-barked species like American beech are easier to penetrate than species with thick bark. But bark of any thickness has weak spots at pores, cracks, and furrows, and at branch junctions where wrinkles bring the inner bark closer to the surface. Wounds in the outer bark open pathways for fungi, bacteria, and insects, but in healthy trees the bark’s chemical and structural defenses can often overcome infections and infestations.

For example, resins in conifers and the gum in black cherry bark repel insects and infectious agents, seal small wounds to prevent infection; they also trap insects. Betulin a substance that whitens the bark of paper birch, deters gnawing animals, fungi, insects, and other invaders. The inner bark of aspen and other members of the willow family contains, salicin which deters bacteria, fungi, and insects.

Structural mechanisms also defend a tree against infection and infestation. Fungi that breach the outer bark, for example, can be walled off, or compartmentalized. This action contains the infection, but it also kills sections of bark by blocking the incoming flow of water and nutrients. The resulting small areas of discolored, sunken, or cracked bark are called cankers.

Even when an infection or infestation is controlled, a tree must contend with the breach that has occurred in the protective outer bark. The inner bark generates cork to surround a wound, and can close small openings and narrow or close large gaps over time. In Maine Eastern hemlock is the only species that produces wound cork in annual increments that you can count – like rings of wood – to determine a wound’s age. Unfortunately, despite its multiple chemical and structural defenses, bark can’t protect trees from all attackers, especially introduced organisms for which a species has no evolved resistance. In many cases foreign pests successfully kill a tree.

However. Some bark-inhabiting fungi and bacteria do no harm. Other fungi and bacteria defend their hosts by out-competing or preying upon canker-causing fungi. These beneficial organisms are often found near weak areas of bark where pathogens might gain entry. When tiny insects, such as springtails and bark-lice, inhabit bark and feed on mosses, lichens, and fungi growing there, they can benefit their host tree by attracting spiders, ants, and other predators that can help control populations of defoliating insects.

At any given moment there are thousands of interactions between the bark and its environment that most of us take for granted. Especially during the winter months if you pay attention to bark you may, like me, develop a deep respect for the unparalleled beauty and for the protective skin of every tree.

Redwood Quest

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(Addertongue only grows in a Redwood forest Biome)

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A whole ecosystem….

 

Totally by accident, I discovered a picture of a most beautiful flower commonly called Adderstongue (Scoliopus bigelovii) that I had never seen before. Of course I had to look it up…

I learned that Adderstongue only grows in old growth forest in the understory of the ancient Redwood trees of California in moist mossy places that are shaded. It grows from a rhizome, and I immediately suspected the plant must have a symbiotic relationship with the Redwood’s underground fungal network. The flower is pollinated by fungus gnats, the fruit is a drooping capsule and when it bursts the seeds are carried away by ants. The moment I laid eyes on the picture I longed to see one in the flesh… and this is what got me started on my Redwood Quest.

Once Redwoods grew throughout North America as well as along the coasts of Europe and Asia, but now they are now restricted to the Pacific coast. And I have never seen one.

The earliest Redwoods -Sequoia sempervirens -(the name Sequoia is Cherokee in origin) appeared shortly after the dinosaurs disappeared. Redwoods have lived in their present form for about 240 million years although California didn’t become their home until about 20 million years ago.

A coastal Redwood tree can grow to 350 feet or more and have a width of 22 feet at its base. Compare this to the tallest pine tree that might be 270 feet high. What amazed me initially was learning that a Redwood’s tap root system extends into the ground for only 6 to 12 feet. However, Redwoods compensate by creating surface roots that grow at least 50 feet from their trunks, and because they live in groves the trees literally support one another by intertwining their trunks and surface roots. Consequently, they have the strength to withstand powerful winds and flooding. Taking down even one tree creates havoc for the whole ecosystem.

Redwoods live a long time perhaps even longer than the 2000 plus years that are allotted them. Many Redwoods around today are 100 – 150 yeas old but a reasonable number reach an age of 600 years.

Studies show that coastal Redwoods capture more carbon dioxide than any other tree on Earth. And, as the climate changes, the Redwood forests are one of very few places that can provide a refuge for plants like the Adderstongue. Many wild creatures thrive in these forests because the area has many micro – climates, and is cooled by coastal summertime fog. California’s North Coast provides the only such environment left in the world. A combination of longitude, climate, and elevation limits the redwoods’ range to a few hundred coastal miles. The cool, moist air created by the Pacific Ocean keeps the trees continually damp, even during summer droughts. Fog precipitates onto the forest greenery and then drips to the forest floor. Fog accounts for about 40 percent of the redwoods’ moisture intake. When fog isn’t present, a grove of redwoods will make its own: a single large tree can transpire up to 500 gallons of water a day. The fog condenses on tree crowns and drips to the earth below. A Redwood’s ability to perpetually move this water hundreds of feet straight up from ground to crown defying gravity is a source of awe to me.

Exactly why the redwoods grow so tall remains a mystery.

Resistance to natural enemies such as insects and fire are built-in features of  coastal Redwoods. Diseases are virtually unknown (or were until recently) and insect damage insignificant thanks to the high tannin content of the wood. Thick bark and foliage that rests high above the ground provides protection from all but the hottest fires.

The Redwoods’ unusual ability to regenerate also aids in their survival as a species. They do not rely upon sexual reproduction, as many other trees do. New sprouts may come directly from a stump or downed tree’s root system as a clone.

Cloning is defined as the process of producing genetically identical individuals of an organism either naturally or artificially. Cloning in biotechnology refers to the process of creating clones of organisms or copies of cells or DNA fragments. Although grammatically correct, I object to the use of the word clone because it suggests to most people an artificial process – one that distances us from the fact that we are talking about a living organism that is reproducing itself. The Redwood’s ability to clone itself means that many of the forest’s trees are related to one another.

Cathedral or family groups are trees that have grown up from the living remains of the stump of one fallen Redwood, and since they grew out of the perimeter, they are organized in a circle. The genetic information in the cells of each of these trees is identical to that of the stump they sprang from.

Amazingly, Basal burls — hard, knotty growths that form from dormant seedlings on a living tree — can also sprout a new tree when the main trunk is damaged by fire, cutting, or toppling.

Undoubtedly, the most important environmental influence upon the coastal Redwood is its own biotic community. The complex soils on the forest floor contribute not only to the redwoods’ growth, but also to a verdant array of greenery, fungi, and other trees. A healthy redwood forest usually includes massive Douglas-firs, Western Hemlocks, Tanoaks, Madrones, among others. The emerald ferns and leafy redwood sorrels, mosses and mushrooms help to regenerate the soils. And of course, when Redwoods die they eventually fall to the forest floor where they decay and provide more nutrients to create new life.

The coastal redwood environment recycles naturally; because the 100-plus inches of annual rainfall leaves the soil with few nutrients, the trees rely on each other, living and dead for their vital nutrients. The trees need to decay naturally to fully participate in this cycle, so when logging occurs, the natural recycling is interrupted.

Many different shrubs populate the understory of old-growth redwood forests. Among them are berry bushes such as red and evergreen huckleberry, blackberry, salmonberry, and thimbleberry. Black bears and other inhabitants of the forest make use of these seasonal food sources.

Perhaps the most famous and spectacular member of the redwood understory is the brilliantly colored California rhododendron. In springtime, rhododendrons apparently transform the redwood forests into a dazzling display of purple and pink colors.

The survival strategies of these trees like their ability to reproduce identical relatives astonishes me. A Redwood that is knocked over will attempt to continue growing via its limbs. If undisturbed, the limbs pointing up will turn into trees in their own right.

Another unusual survival strategy is the Redwood burls. The growth of a burl is held in check by the presence of chemical signals in a living Redwood. However, if the tree should die, or even be stressed, say by drought or fire, the chemical signal weakens or vanishes and the burl will burst forth into verdant life. Burls kept in a shallow pan of water will grow almost indefinitely. They can also continue on to become a full grown redwood tree.

Sexual reproduction can also occur by seeding. About 20% of today’s present Redwood trees sprang from seeds ( some Redwoods don’t even produce them). The rest came from one of the various cloning/family-based proliferation strategies. This means that some of these trees could be the latest incarnations of the same line that stretches back 20,000 or 30,000 years.

Coastal Redwoods also have the unique ability to survive rising soil levels. Rising ground levels are commonly brought about by flood deposits, deposits that typically smother other trees root systems, killing them. The Redwood simply grows a new lateral root system. Seven successive layers of roots were observed on one fallen Redwood meaning that the ground level had risen dramatically up the tree seven times and each time the tree responded with a new root system. It has been observed that some 1000+ year old Redwoods have experienced and survived rises in ground level of as much as 30 feet.

Redwoods compensate for induced leans caused by shifting slopes, collisions of other trees, flood pressure and tectonic induced tilting, by the unusual ability to “buttress” their undersides through accelerated growth on the downhill side. What this means practically is that it is possible to find whole groves of trees that are leaning in the same direction.

Recalling that as a human I share 25 percent of my DNA with trees, it seems quite natural that I would want to meet a forest composed of my most astonishing relatives and perhaps visit with the Addertongue in the process!

Nature’s Gold – The Aspens

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Nature’s Gold – The Aspen

 

Every morning I set off to the river and to my refuge, the Bosque, walking under dying cottonwoods whose bark is peeling away from dead tree limbs. Just in the past summer a few of these magnificent matriarchs have crashed to earth providing nutrients that will one day support some other kind of ‘tree of life’.

 

My dreams tell me that new as yet unknown species will begin life here, offering me comfort because as a dreamer I have learned that my dreaming body knows what I do not, no doubt because she is attached to the body of this precious earth.

 

When I pass by the coyote willows I think about how cottonwoods, aspens, and poplars are part of the Willow family. Recent genetic testing reveals that this diverse group also includes passiflora (my beloved passionflowers) and wild violets too! – I was astonished by this last piece of information until I realized that all require adequate water to thrive.

 

Coming from the Northeast where quaking aspen can be found throughout the state of Maine I was still surprised to learn that these trees stretch across the entire continent. Aspens hold the title of being the most widespread tree in North America. They can be found from the Midwest, across Canada, north into Alaska and across the West through to Arizona and into New Mexico.

 

One aspen tree is actually only a small part of a larger organism. A stand or group of aspen trees is considered a singular organism with its central life force hidden underground in an extensive root system that I think is analogous to the human brain (I am not alone in this speculation). Before a solitary aspen trunk appears above the surface, the root system may lie dormant for many years until conditions are just right. In a single stand, each tree is a genetic replicate of the other, hence the name – a “clone” of aspens used to describe a stand.

 

Older than the massive Sequoias or the Bristlecone Pines, when the Pando clone was discovered, scientists named it with a Latin word that means “I spread.” Pando is an aspen clone that originated from a single seed and increases by sending up new shoots from its underground expanding and complex root system.

Pando is believed to be the largest, most dense organism ever found on earth. It weighs nearly 13 million pounds (6,600 tons). The clone spreads over 106 acres, consisting of over 40,000 individual trees. The exact age of the clone and its root system is difficult to calculate, but it is estimated to have started at the end of the last ice age. It was first recognized by researchers in the 1970s and more recently proven by geneticists. Its massive size, weight, and prehistoric age have caused worldwide fame.

Located in central Utah (Fishlake National Forest), Pando is dressed in verdant green throughout the summer. Her fluttering leaves bring relief from summer’s intense basin heat. In autumn the oranges and yellows and sometimes crimson leaves rival the most spectacular New Mexican sunset.

However, there is deep cause for concern because Pando is showing signs of decline. The organism is not regenerating, invasive insects are present, as are diseases. Unfortunately throughout the west, diebacks of other aspen stands are becoming more common. No one mentions climate change or loss of habitat as an issue.

The prevailing logic is that even if the trees of any stand are wiped out, it is still difficult to extinguish an aspen’s root system permanently due to the rapid rate in which it reproduces, thus there is hope.

It’s hard to decide what is most memorable about aspen: the vibrant gold leaves in fall, the startling pearl white stands, or the magical sound of the “quaking” leaves.

Among swaths of dark green conifers, the deciduous aspen stands thrive in a variety of environments. Aspens quickly colonize recently burned or bare areas (with birches in areas that support the latter like they do in Maine). They prefer moist soil but can survive near springs in desert conditions. Like the rest of the willow family these trees must have access to water. Because the Southwest is under siege from increasing drought as a result of climate change, I wonder if lack of adequate water is the reason why these trees are not regenerating.

 

One of the most fascinating aspects of aspens is that they grow all winter, a fact I didn’t know, but should have suspected because the trees around my house have a greenish cast. Beneath the thin, white outer bark layer is a thin green photosynthetic layer that allows the tree to create sugars and grow when other deciduous trees are dormant. This characteristic is unique among deciduous trees. During hard winters, the green, sugary layer provides necessary nutrients for deer and elk. Throughout the year, young aspens provide food for a variety of animals including moose, black bears, beaver, porcupine, grouse and rodents.

 

Perhaps most impressively, quaking aspen along with sister species (distributed in Europe and Asia) occupy the broadest range of any tree species in the world. Why is that so? Possibly one reason might be because the bark carries out photosynthesis all year long allowing the stands to expand their geographic range.

 

Aspen drops its leaves in winter but, of course, remains alive and thus requires metabolic energy. The soft tan to greenish hues often visible in aspen bark mark an important photosynthetic capability provided by the differing levels of chloroplasts. Stem photosynthesis contributes significantly to aspen’s over-wintering survival capabilities. The disadvantages of this type of bark include low fire resistance, ease with which people carve their initials in these trees creating space for disease to enter, and that the trees are an excellent food source for elk, deer etc. Numerous insects and fungi that attack the bark are also considered potential problems.

Aspen form individual patches comprised of numerous stems, each with its own trunk, branches, leaves and a shared root system. All of these structures originally arose from a single aspen seed that germinated in the distant past; The patches remain connected via root systems, and if the root system between patches is severed, the patches form physiologically separate clumps but are generally still considered part of the same clone because they are composed of genetically identical parts. The boundaries of different clones stand out most clearly in the early spring when flowering and leafing-out occur (in that order). Aspen have male and female catkins, unlike the majority of tree species, which support both male and female reproductive parts on each individual.

 

During early spring in an aspen clone the reproductive male catkins produce pollen while the female produces eggs. Huge numbers of viable, tiny seeds mature and float off from the female on a tangle of cotton-like seed hairs that catch air currents, sometimes traveling great distances. Immediately after shedding their pollen and seeds, the clones then produce leaves that usually appear at the same time in all stems of a given clone revealing the boundaries between clones most visibly. In the fall the striking leaf colors do not mark clonial boundaries as reliably because the chemical processes that produce the colors tend to be very sensitive to local micro-climate conditions. A single clone may also exhibit multiple colors simultaneously. In aspen, all the pigments that give rise to these glorious colors can be found in the leaf from spring all the way through fall when the aspen begin to first break down the green chlorophyll molecules that are responsible for spring and summer color. Other pigment molecules then become more and more visible.

 

For many years, most western forest ecologists thought aspen reproduction from seeds was rare. However, it turns out that successful establishment of aspen via seeds occurs more frequently than previously believed. The ability of aspen to produce whole stands of “trees” vegetatively provides yet another key element in explaining the species’ ability to occupy huge geographic ranges.

There are several benefits of asexual expansion. The clones share resources. One part of a clone might be near an important water source and share its water with drier parts of the clone while those in a drier area may have greater access to the vital soil nutrient, phosphorous, and share that resource with those that are low in this nutrient.

 

Quaking aspen also tends to be a disturbed habitat species, meaning it often lives where avalanches, mudslides and fires occur frequently. So both the regenerative capability and the clonal reproductive capability allow aspen to initially establish or to re-establish into an area after disturbances like mud slides occur. Similar patterns often follow forest fires. Rarely will a fire burn hot enough to kill the entire root system from which these stems arise, so an individual clone may occupy a given space and be completely wiped out on the surface but re-grow from the root system many times.

 

If an aspen stand does not experience periodic disturbances such as natural fire or avalanche, more shade-tolerant conifers tend to establish and shade out the high-light-requiring aspen stems. If the disturbances are too frequent, then the clone cannot spread.

Clone structure varies with geography but also varies due to the strong influences of rainfall and relative humidity. The largest clones generally occur in semi-arid environments such as the mountains of the western and southwestern US. Clones tend to be smaller in areas where the climate supports seed germination.

The last particular attribute of quaking aspen important in contributing to its ability to occupy huge ranges derives from the comparatively high level of genetic variability among clones. These interclonal levels of variability provide raw material for evolutionary change across generational times. The large number of seeds produced from genetically variable sources generates an enormous array of potentially successful genotypes for establishment in newly opened areas and probably takes place at higher rates.

One of the most enchanting aspects of aspen is their ability to quake and tremble in the slightest breeze. Why do quaking aspen leaves quake and tremble? This is due to the physical structure of the leaf stem which traces a flat, oblong, elliptical pattern when viewed in cross section so it has strength in one dimension and minimal strength in the second dimension, so even a gentle wind causes produces movement and a hypnotic sound. Plant physiologists have pointed out several reasons for the trembling leaf behavior. They include minimizing the risk of too much sunlight as well as reducing the risk of overheating in intense, high elevation. Trembling also improves photosynthetic rates by keeping a fresh supply of carbon dioxide near the leaf surface where the plant takes up that compound. Insect damage may also be reduced by fluttering leaves.

This tree species seems to almost have it all: powerful, opportunistic, sexual reproduction, long-distance seed dispersal, effective vegetative spread, clonal reproduction, regeneration from roots, high levels of genetic variability, living bark and a potentially enormous life span.

And in my mind, Pando certainly represents one of the most remarkable “families” among all living organisms.

 

Postscript:

The language used to describe these remarkable organisms that cooperate by share root systems, information, and resources seems woefully inadequate. To call a phenomenal organism like Aspen a “clone”, although grammatically correct, is to reduce it to its lowest denominator. These trees live harmoniously within a family that supports the continuation of life, not just for one tree but for all its relatives. Most important this species has been self- sustaining for millennium.