There is no pool in July.  It is dead leaves and dust in a shallow depression.  There are no understory plants, no young trees, just the shade of larger trees on the edge and in the high spots within the space.  It is easy to walk through this dry spot, unlike the surrounding woods with young trees and fallen wood.  

In autumn, it might get damp.  But in winter, it fills with snow.  One dry winter almost left it empty, but right at the end, a storm come through.

And then there is spring.  It thaws, the water is full of dead leaves, it darkens like strong tea, and things begin to wake up.  There are no leaves on the trees so the sunlight penetrates the murky water. Mosquitoes are common, as are beetles of several kinds, and the occasional water boatman.  Phantom midge larvae bend and straighten in the brown water.  Egg masses appear, frogs certainly, and maybe salamanders.  I don’t obsess about the amphibians the way some people do, but these eggs are impossible to miss.  They are colorful in their jackets of jelly.

But the headline attractions are fairy shrimp.  They are orange and green and some other colors, with patches of iridescence.  They are pretty big as adults (up to 2 cm), and slow, and they swim upside down.  The males have weird appendages that resemble elephant trunks.  Both males and females eat whatever they can find in the stew of organic debris, grow fast, mate, produce eggs, and die.  It’s over quickly.

It has to be.  The pond is drying.  There is no outlet stream, so no fish can reach it.  And no fish can live here when it dries up.  The pond creatures would be gobbled up quickly by fish, so this is one of the few places they can succeed.  But there is a price for safety, and that is time.  There isn’t much time.  Get your breeding done, and leave (if you’re a flying or crawling insect or a metamorphosed amphibian), or go dormant.

There are fairy shrimp eggs in that dust of July, in the soil and leaves, waiting.  Summer is too soon.  Autumn is too dry.  Winter is too cold and frozen solid.  Only spring will do.  Once a year, spring is the season of explosion.  Live fast, and go out in a blaze of glory. 

When there are sharp seasons of the year, there will also be sharp rises and falls of growth, life, breeding, and death.  If you can’t cope, get out.  Come back when it’s better.  And if you can cope, then congratulations on evolving a weird life cycle.  Adaptation is alive and well in a vernal pond, and in every other thing around it.