Aug 3, 2011

Swamp step stool

The swamp mosaic covers a wide horizontal expanse.

But vertically – from top to bottom – it’s a short ladder will do fine.

This graph displays recent rain and water depths in the swamp
relative to the twenty-year historical statistics

The way I see it,

The swamp ladder contains six rungs:

Rung 1 gets you into the dry season refugia pools. Dry season refugia are small-scale (usually less than an acre) pools of perennial-flooded open water in the preserve. These pools typically contain swamp flora at their fringes (i.e., emergent plants, pond apple, cypress) but are free of vegetation within, thus they are technically not a wetland. Water depths generally range from 3 to 5 feet during the wet season and most importantly tend to hold water all year round, although during deep dry down years they too may go dry.

Rung 2 takes you up to pond apple and marsh. Pond apple forests and marshes are the deepest wetland habitat in the preserve. Both areas hold surface water the deepest (18-24 inches) and longest (9-11 months) of any other wetland type in the Preserve.

Rung 3 you’ll see tall cypress. Tall Cypress forests are generally found towards the middle of the preserve’s forested flow ways (called strands) and cypress domes. Tall cypress hold water at a maximum depth of 12-18 inches during the late summer months, with a total inundation period of 7-9 months.

Rung 4 is marl prairie. Marl prairies are characterized by a calcium-carbonate rich marl substrate and a variety of grasses and sedges, including sawgrass, stands of dwarf cypress , and interspersed marshes, pinelands, and cypress domes. Marl prairies holds standing water for 5-7 months at a maximum summer depth of 6-12 inches, during which submerged periphyton mats appear.

Rung 5 is hydric pinelands. Hydric uplands are commonly found as open stands of slash pine with sparse to no woody ground cover, or as more smallish hydric hammocks. Hydric uplands hold standing water for around 3 months at a maximum summer depth of 2-6 inches.

At the top at Rung 6 – stratospheric by swamp standards – you’ll be among the mesic pine flatwoods and hardwood hammocks. Mesic uplands are usually found as stands of slash pine with denser woody under cover, including palmetto, occurring as either isolated islands (i.e., Thompson’s Pine Island) or as the predominant vegetation type (i.e., Raccoon Point). They hold standing water for under 1 month at a maximum summer depth of under 2 inches.

Summer water levels are back up,
but the spring drydown was unusually deep.

Plan on bringing a GPS unit to horizontally traverse the mosaic,

But vertically (and hydrologically) a step stool will do just fine!

1 comment:

Janie said...

That's an interesting list. We have the same kind of thing with a little different plant growth at each altitude step.