RSS

Category Archives: Meadow Succession

Middle Aged Meadows and the Middle-Loving Plants

I’ve always loved sunshine, butterflies, goldenrods, and fragrances in cheerful meadows evocative of childhood memories.

Meadow Peacock

Meadows and butterflies, it’s only natural!

Attractive meadows in the Cypress Creek Natural Area near Jupiter, Florida, reflect several years of recovery after clearing and abandonment.   They represent a middle-successional stage.   Let me explain:

A textbook topic in Ecology is succession. Setting aside a couple controversies, the concept of ecological succession traces the history of a cleared area from its recolonization by annual pioneer weeds through a series of  plant communities onward and upward stepwise to a stable “climax” forest.      The stages and “final” outcome depend on the starting conditions, the basic habitat, and events.   The general trend with passing decades is from small and ephemeral toward large, heavy, and long-lived.

IMG_0582.JPG

Today’s meadows represent a middle stage in succession.  A fairly predictable clique of species dominates such a mid-successional moist meadow.  What do the middlers have in common?    They are not just midway in successional time, but also in structure,  not exactly weeds,  pretty big, but not exactly hunky woody shrubs or trees either.   Tweeners adapted to life in the middle, just like 8th graders in Middle School.

As succession begins the pioneer weedy species compete mostly simply to arrive, persist briefly, and disperse seeds.   But conditions change, becoming more crowded with the incoming  species being ever-taller and broader.  Mid-succession competition becomes a fight for the light, the winners rising above those who came before.    Then still later at the climax community the competition shifts again, to bearing  youngsters able to cope with the canopy shade.

Let’s go back to mid-succession and that contest to rise into the life-giving light.  The perennial weeds in our meadow are fairly tall:   goldenrods, musk-mints, and bluestem grasses as tall as I am.    The species able to surpass those perennials often are bare toward the base where the sun don’t shine,  the foliage held at 4-10 feet as required to overtop the big weeds.   Achieving comes to require some degree of woodiness.

Meadow fennel

Dog Fennell with bare “bamboo” stems lifting the foliage above competitors.

The “beginner” of woodiness is Dog Fennel,  often with stems resembling bamboo, even by having “tubular” construction the stem becoming a slightly woody cylinder around a soft pithy core.   The stems live just one season yet become just woody enough to carry the canopy aloft.   The perfect balance between “fast cheap expendable growth” and height.  It can’t decide if it is a pioneering weed or a woody shrub, a little of both.

Meadow fennel pith

Dog Fennell almost hollow.

Also dominant are Saltbushes.   Along with Dog Fennell they represent the Aster Family which is usually non-woody, yet these Baccharis species have just enough woodiness to stand up and fight.    Relevantly, biologist P.B. Tomlinson, in his “The Biology of Trees Native to Tropical Florida” noted how  despite having a woody trunk, Saltbushes “more resembles an herb.”  He observed further that, “most of the woody branches are short-lived so that older plants are characterized by a mass of dead twigs.”

Meadow Baccharis

Saltbush, alive up high, shedding dead branches down low.

That tendency toward dead twigs sounds like abandoning crowded older growth in favor of new growth where sunlight is plentiful.   Saltbushes are not alone in tending to go bare down low.   Slash Pines appear as saplings early in succession, growing with the successional stages.  As they rise, the pines have an early bare base, and then begin a lifelong habit of shedding lower branches.  Observers usually interpret this as protection from ground fires, but that does not rule out a secondary benefit of lifting the leafy crown above rising competitors (which could fuel a ground fire).

Meadow pine

Another species sometimes prone to die down low  and  renew with tufts of leaves up high is Wax Myrtle, one of the dominant mid-successionists.   It and Saltbush have separate male and female individuals.

Meadow Wax Myrtle older

Wax Myrtle can dare to be bare below, with tufts above.

Wax Myrtle is one of the select few plants other than Legumes to have nitrogen-fixing root nodules,  giving it a competitive advantage on the terrible soils underlying the entire meadow.

Meadow nodule

On the Wax Myrtle root.

 
8 Comments

Posted by on November 16, 2018 in Meadow Succession, Uncategorized

 
 
%d bloggers like this: