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A new grassy meadow grows in the basin of a former beaver pond |
Typically, when
beavers abandon a pond, the habitat quickly regenerates into meadow. Grass
seeds and the seeds of many other plant species begin to sprout in the rich
silted-up soil, and within a few weeks a lush sea of grass grows where once
beavers swam. The beaver meadow continues to evolve; that is as long as beavers
refrain from re-flooding the area. The first year, not much diversity will be
encountered and the meadow is dominated by grass and only a few other easily
perceptible plant species, but only a year later, plant diversity increases
tremendously and a wildflower meadow is born.
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Blue Vervain plants grow plentifully in the beaver meadow |
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The old beaver dam is covered with wildflowers |
Undoubtedly, many
of us recognize the good work that beavers do by creating water impoundments
–and therefore wetland habitat for scores of other creatures, but few of us
give them credit for their gardening work. Even without a
beaver meadow, a beaver dam can act as a raised garden –hosting thousands of
blooms along its span and providing food resources for hummingbirds and
butterflies as well as a source of forage and bedding material for muskrats and
for the beavers themselves.
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Square-stemmed Monkey-flower grows in the new meadow |
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Swamp Candles (or Yellow Loosestrife) is in the Primrose family |
When our old farm
fields are left alone to evolve as they will, most in our region become
dominated by goldenrods and asters as well as alien invasives like spotted
knapweed. These plants generally attain a lock on the habitat and will not easily be
displaced. They will certainly not be nudged aside by any less aggressive
flowers. In other regions of the country, fire acts a disturbance factor in the
environment as it clears an area of its dominant plants and allows a new plant
community to develop. In our area, it's the beavers introduce the disturbance
factor and are therefore the fathers (and mothers) of distinct meadow types in
a given environment.
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Yellow Moth Mullein is in the snapdragon family |
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Northern Willow-herb has very small blooms |
The succession of
plants that colonize the beaver meadow are surprisingly different than those
which dominate our adjacent old fields. A lot of this difference is by chance,
since it depends on what plant seeds are inherent in the given environment. But
in my experience new beaver meadows even in the same area will not all develop
in the same way. This may be explained by the varying prevalence and
reproductive success of local plants on a year-to-year basis.
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A Northern Pearly-eye Butterfly at the meadow's edge |
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The first Hickory Hairstreak Butterfly of the season |
Plant make-up in
the beaver meadow will continue to evolve as the years go by. The first 2 years
or so, annuals and biennials might make up a greater proportion of the meadow's diversity,
but in subsequent years, perennials will become established and eventually dominate –at least up until the meadow is re-flooded and transformed into a
pond once more.
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Not a beaver meadow - but our main wildflower meadow, now dominated by spiderwort |
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A small proportion of the spiderwort flowers are pale blue |
Oddly enough,
this year the meadow that once was home to Sarah's Pond is now hosting an
outstanding bloom of Moth Mullein. Just where all those Mullein seeds came from
is a mystery. I've never seen more than a few of these plants in the surrounding
fields for the past dozen years. It’s conceivable that these seeds, along with
those from dozens of other diminutive species were there all along, lurking in
the silt at the bottom of the pond –biding their time and waiting for their
chance to sprout.
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A buck lays down and remains partially hidden in a corner of the field |
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A Spring Azure Butterfly (very small) lands on my shoulder |
Blue Vervain,
which dominated the beaver meadow last season is back again in a big way this
year. The copious amount of rainfall that we've received in the last several
weeks have suited them fine, and they are growing taller than usual, and
mingling well with the tall mulleins.
Awesome!
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