FOR YOU, ABRAM! FOR YOUUUUUU! (a.k.a. Tree of the week for April 3-10 2010: Acer saccharinum)
Spring is a-come here in Bangor and the low, boggy forests that surround it; and when I think of spring in that vast region of North America bordered by the Great Lakes & St. Lawrence, the Mississippi, the Ohio, and the Atlantic, I think of the silver maple. So here's an entry about that.
Synonyms: "Soft Maple", "Swamp Maple", "Silverleaf Maple", Acer saccharinum
Range & Habitat: Silver Maple is one of the most common trees to line the banks of Northeastern rivers and streams. Both young and old trees are very well-adapted to surviving long periods of flooded soils, and so they come to dominate areas where such occurrences are frequent, including also the borders of lakes and some swamps and poorly drained depressions. It also has been planted with great frequency in the yards, parks and streetsides of our nation. Geographically, its natural range extends from just north of the Gulf coast of Mississippi and Alabama up into the deciduous forest zone of eastern Canada, and west along great rivers well into the plains states of Nebraska, Kansas and Oklahoma. In 1800 it was absent from the low-quality soils of Michigan's Upper Peninsula, Cape Cod, and the sub-boreal forests of northern Minnesota and far northern Maine, but since then it has spread from urban and rural plantings to naturalize along the river and streambanks of even these remote locations. And, of course, we Easterners brought the tree with us further onto the great plains, the Rocky Mountains, and even to the Pacific coast as we conquered and occupied these lands; though I wot not how extensively it's naturalized there.
Native? Y/N: Yes, yes, a thousand times yes!
Plant ID: By its jagged, five-pointed leaves1, with their deep indentations and pale, silvery undersides may you know the silver maple during the growing season. In early spring, its tiny red-green buds and flowers2 are among the first signs that the long winter is at an end, and they are a much more reliable one than Pennsylvania's much-ballyhooed Phil. The seeds - carried on the graceful samaras3 that the whole genus Acer is heir to - are produced soon after, and fall throughout the spring and earliest summer. In fall, as evidenced by the picture of some graceful trees alongside the Stillwater River, the tree's leaves turn a pale, delicate yellow that speaks, to this author at least, of faded glories and winter's long sleep. And even when its branches are bare, all during the winter, this tree may be known by its peeling and flaking bark. It shares this trait with its close relative, the red maple, Acer rubrum; but the two may be distinguished by the silver maple's propensity for a multi-stemmed, wide-canopied, heavily branched form4, and by its love of running water and open streambanks, in contrast with red maple's preference for dismal and stagnant swamps.
Ecology: As indicated above, A. saccharinum is a tree of streambanks, of floodplains, seasonal wetlands, and the edges of lakes. It loves soil that is moist and rich with sediment brought down from distant mountains. It uses the water and nutrients there available to propel a rapid growth - two feet in height per year with great regularity under good conditions. According to the USDAFS's Silvics Manual, it may also on occasion be found growing in low-quality, acidic peats and mucks, but is rare and stunted in these conditions. I can say that I, for one, have never seen it in such a location, but I bow to their superior scholarship.
The tree is well adapted to its life in these places. It can withstand extended floods unharmed. For example, recently the Penobscot River has been hugely swollen with spring rains & snowmelt, and many low gravelly islands in the middle of its course have been under several feet of water. These islands, in turn, support stands of quite decently sized silver maples, who have clearly weathered many such springs of waste-high floods. In fact, it uses these floods to its advantage, as they eliminate competitors who cannot take the deoxygenated soil, while simultaneously laying nutrients and moisture at the silver maple's feet, like so much tribute before some victorious emperor of old.
But not even evolution can allow one to maximize efficiency across all variables at once, and the fast-growing, flood-tolerant silver maple has one strict requirement: it needs much sunlight. If overtopped by competitors, its growth will trickle to almost nothing, and 'twill likely die. It is for this reason that the tree so favors a wide, many-branched canopy form. This allows it to spread its branches far over5 whatever water body it's next to, where there is no other foliage to compete with it.
Uses and Silviculture: A silver maple may be put to its best use simply by leaving it be. For along the banks of rivers and marshes, it purifies water and stabilizes soil; and anyone who is enough of an environmentalist to be reading this well knows how valuable, and how vulnerable, those two commodities are. Even beyond these excellent reasons for letting it be is the extent of its utility to wild animals. Its soft, weak wood readily forms cavities that are soon occupied by any of a number of cavity-nesting birds and mammals, and according to several sources6 the early buds it produces are a critical foodstuff for squirrels in late winter, when their cached food is running low. The same sources also note that the tree's generally abundant seed crop are an important food source for breeding birds, including wood ducks and wild turkeys.
The tree is also planted rather extensively in urban suburban areas, where its year-round beauty, ample shade, and rapid growth are valued. My hometown of Downers Grove, Illinois has many such silver maples gracing the yards of its older houses. Quick visual estimate, aided by examining the houses they are near, places most of these trees at somewhere a little over a century in age. In that time, they have become quite large indeed, many of them possessing a bole of 3+ feet at breast height.
In addition to the living tree's utility, silver maples ought to be spared wherever encountered because their corpses possess so little value. The wood is brittle and tends to be rendered knotty by the tree's preferred growth habit. Still, the forest service reports6 that silver maple "is a valued timber species in the Midwest." They further claim that it is used for "furniture, boxes, crates, food containers, paneling, and core stock" [i.e. underneath a handsomer veneer]. While I am not at all convinced that these trees were indeed made better use of by being felled, I do believe that, should American farmers and foresters ever take up the art of coppicing with as much enthusiasm as the European peasantry did of old, then silver maple, with its abundant root suckers and fast growth, would be an excellent choice for such management.
Taxonomy: Once, the maples were placed in a family all of their own, the Aceraceae. However, modern taxonomy has made a strong case that this family should be folded into the vast Sapindaceae, the soapberry family. This largely tropical family includes the lychee of Chinese cuisine and the state tree of Ohio, the buckeye. Within the maples proper, Acer saccharinum is generally thought to be a sister of another North American tree, the abundant red maple Acer rubrum, previously covered on these pages.
Previously covered since 1986,
--mark
1 Photo courtesy of Michigan State University
2 Photo courtesy of Vanderbilt University
3 Photo courtesy of the University of Nebraska at Lincoln
4 Photo courtesy of the Pennsylvania Forestry Association
5 Photo courtesy of the Couchiching Conservancy
6 Including the USDAFS Silvics Manual and the Forest Service's fire ecology information service.
Synonyms: "Soft Maple", "Swamp Maple", "Silverleaf Maple", Acer saccharinum
Range & Habitat: Silver Maple is one of the most common trees to line the banks of Northeastern rivers and streams. Both young and old trees are very well-adapted to surviving long periods of flooded soils, and so they come to dominate areas where such occurrences are frequent, including also the borders of lakes and some swamps and poorly drained depressions. It also has been planted with great frequency in the yards, parks and streetsides of our nation. Geographically, its natural range extends from just north of the Gulf coast of Mississippi and Alabama up into the deciduous forest zone of eastern Canada, and west along great rivers well into the plains states of Nebraska, Kansas and Oklahoma. In 1800 it was absent from the low-quality soils of Michigan's Upper Peninsula, Cape Cod, and the sub-boreal forests of northern Minnesota and far northern Maine, but since then it has spread from urban and rural plantings to naturalize along the river and streambanks of even these remote locations. And, of course, we Easterners brought the tree with us further onto the great plains, the Rocky Mountains, and even to the Pacific coast as we conquered and occupied these lands; though I wot not how extensively it's naturalized there.
Native? Y/N: Yes, yes, a thousand times yes!
Plant ID: By its jagged, five-pointed leaves1, with their deep indentations and pale, silvery undersides may you know the silver maple during the growing season. In early spring, its tiny red-green buds and flowers2 are among the first signs that the long winter is at an end, and they are a much more reliable one than Pennsylvania's much-ballyhooed Phil. The seeds - carried on the graceful samaras3 that the whole genus Acer is heir to - are produced soon after, and fall throughout the spring and earliest summer. In fall, as evidenced by the picture of some graceful trees alongside the Stillwater River, the tree's leaves turn a pale, delicate yellow that speaks, to this author at least, of faded glories and winter's long sleep. And even when its branches are bare, all during the winter, this tree may be known by its peeling and flaking bark. It shares this trait with its close relative, the red maple, Acer rubrum; but the two may be distinguished by the silver maple's propensity for a multi-stemmed, wide-canopied, heavily branched form4, and by its love of running water and open streambanks, in contrast with red maple's preference for dismal and stagnant swamps.
Ecology: As indicated above, A. saccharinum is a tree of streambanks, of floodplains, seasonal wetlands, and the edges of lakes. It loves soil that is moist and rich with sediment brought down from distant mountains. It uses the water and nutrients there available to propel a rapid growth - two feet in height per year with great regularity under good conditions. According to the USDAFS's Silvics Manual, it may also on occasion be found growing in low-quality, acidic peats and mucks, but is rare and stunted in these conditions. I can say that I, for one, have never seen it in such a location, but I bow to their superior scholarship.
The tree is well adapted to its life in these places. It can withstand extended floods unharmed. For example, recently the Penobscot River has been hugely swollen with spring rains & snowmelt, and many low gravelly islands in the middle of its course have been under several feet of water. These islands, in turn, support stands of quite decently sized silver maples, who have clearly weathered many such springs of waste-high floods. In fact, it uses these floods to its advantage, as they eliminate competitors who cannot take the deoxygenated soil, while simultaneously laying nutrients and moisture at the silver maple's feet, like so much tribute before some victorious emperor of old.
But not even evolution can allow one to maximize efficiency across all variables at once, and the fast-growing, flood-tolerant silver maple has one strict requirement: it needs much sunlight. If overtopped by competitors, its growth will trickle to almost nothing, and 'twill likely die. It is for this reason that the tree so favors a wide, many-branched canopy form. This allows it to spread its branches far over5 whatever water body it's next to, where there is no other foliage to compete with it.
Uses and Silviculture: A silver maple may be put to its best use simply by leaving it be. For along the banks of rivers and marshes, it purifies water and stabilizes soil; and anyone who is enough of an environmentalist to be reading this well knows how valuable, and how vulnerable, those two commodities are. Even beyond these excellent reasons for letting it be is the extent of its utility to wild animals. Its soft, weak wood readily forms cavities that are soon occupied by any of a number of cavity-nesting birds and mammals, and according to several sources6 the early buds it produces are a critical foodstuff for squirrels in late winter, when their cached food is running low. The same sources also note that the tree's generally abundant seed crop are an important food source for breeding birds, including wood ducks and wild turkeys.
The tree is also planted rather extensively in urban suburban areas, where its year-round beauty, ample shade, and rapid growth are valued. My hometown of Downers Grove, Illinois has many such silver maples gracing the yards of its older houses. Quick visual estimate, aided by examining the houses they are near, places most of these trees at somewhere a little over a century in age. In that time, they have become quite large indeed, many of them possessing a bole of 3+ feet at breast height.
In addition to the living tree's utility, silver maples ought to be spared wherever encountered because their corpses possess so little value. The wood is brittle and tends to be rendered knotty by the tree's preferred growth habit. Still, the forest service reports6 that silver maple "is a valued timber species in the Midwest." They further claim that it is used for "furniture, boxes, crates, food containers, paneling, and core stock" [i.e. underneath a handsomer veneer]. While I am not at all convinced that these trees were indeed made better use of by being felled, I do believe that, should American farmers and foresters ever take up the art of coppicing with as much enthusiasm as the European peasantry did of old, then silver maple, with its abundant root suckers and fast growth, would be an excellent choice for such management.
Taxonomy: Once, the maples were placed in a family all of their own, the Aceraceae. However, modern taxonomy has made a strong case that this family should be folded into the vast Sapindaceae, the soapberry family. This largely tropical family includes the lychee of Chinese cuisine and the state tree of Ohio, the buckeye. Within the maples proper, Acer saccharinum is generally thought to be a sister of another North American tree, the abundant red maple Acer rubrum, previously covered on these pages.
Previously covered since 1986,
--mark
1 Photo courtesy of Michigan State University
2 Photo courtesy of Vanderbilt University
3 Photo courtesy of the University of Nebraska at Lincoln
4 Photo courtesy of the Pennsylvania Forestry Association
5 Photo courtesy of the Couchiching Conservancy
6 Including the USDAFS Silvics Manual and the Forest Service's fire ecology information service.