Adaptations of seasonal and temporary wetland communities

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Adaptations of seasonal and temporary wetland
communities
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Definitions

• Seasonal wetlands are nontidal wetlands that are
  flooded for extended periods in the growing
  season.
• Temporary wetlands are nontidal wetlands that
  contain surface water for brief periods in the
  growing season.

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• Intermittent waters become dry at times of the
  year that are more or less predictable.
• Episodic waters are water-filled on a more or
  less unpredictable basis.

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Characteristics

• Lentic waters
• Closed environment
• Lack of fish
• Presence of fairly shrimp and
• tadpole shrimp

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• Winter
• Verna pools
• Seasonal marshes
• Flooded grasslands
• Playas Spring
• Desert depressions
• Rock pools
• Summer

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• Invertebrate and plant communities are affected
  by duration, timing, and frequency of flooding.
• Adaptations are
• Morphological
• Physiological
• Behavioral.

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• Three main evolved strategies for surviving the
  dry season
• Life history modification
• Physiological tolerance
• Migration

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1 Life History Modification

• Wetland invertebrates exhibit
• High powers of dispersal
• Rapid growth
• Short life-span
• Small size
• Opportunistic/Generalistic feeding
• Wetland plants exhibit
• Rapid growth/reproduction (8 to12 weeks)

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Fairy Shrimp

• 16 day life cycle
• 1/2 1 in size
• Feed on algae, bacteria, protozoa, dead
  tadpoles and mollusks.
• Easily dispersed by wind or water fowl.

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2 Physiological Tolerance

• Synchronous life cycle.
• Diapause during stages
• in the life cycle that
• coincides with drought.

Delta Green Ground Beetle Elaphrus viridis
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• Production of dormant egg and seed propagules
• Plants
• Wetland plants will germinate with the first
• winter rains.
• Grow while the pool is full of water.
• Flower and set seed as the water
• evaporates.

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• Invertebrates
• Wetland invertebrates lay their eggs in the
• sediment.
• Development is allowed to occur in the
• absence of water.
• Emergence occurs when the pond floods
• again.

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Benefits of a long-lived egg and seed bank

• Maintain genetic, species and community
  diversity.
• Food for migrating waterfowl and shorebirds.
• Predator and competitor free environment.

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3 Migration

• Divided into two forms
• Active Requires power of flight. Seen
  mostly in insects.
• Passive used by smaller plant and animal
  species that are not able to migrate unassisted.

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Active migration

• Pantala flavescens
• The Wandering Glider
• Breeds in temporary ponds, exhibits long-distance
  dispersal.
• At emergence adults fly upward and are
  transported by the wind.

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Passive Migration

• Wind and surface drainage dispersal.
• Transportation by waterfowl.
• Transportation by insects.

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Importance of seasonal and temporary wetlands

• Increased fitness demands lead to greater genetic
  diversity.
• Habitat for distinct species that are not found
  elsewhere.
• Maximizing the gene pool of species that occur in
  both temporary and permanent waters.