Saltmarsh Thatch
If the thatch is pulled apart to expose the ground surface a number of animals can be found. As soon as the thatch is parted the animals will move into the undisturbed areas.
The most common residents of the thatch are:
Sandhoppers or beach fleas
- amphipod - a type of crustacean that has a laterally flattened body
- jumps when disturbed (up to 1 m)
- can also run, climb and swim
- less than 2 cm in length
Plant hoppers
- insect with mouthparts modified to form a stylet (sucking mouth parts)
- usually found on plants rather than ground
These animals eat dead organic matter (sandhoppers and beetles), plant sap (plant hoppers), and other animals (beetles and spiders). There are, in fact, very few herbivores on the saltmarsh. There is evidence for this in that there are no partially eaten leavesand there is a high standing crop biomass. Possible reasons for the lack of herbivory includes the lack of large native grazers, high salt content of tissue and high fiber content of tissue (must be very tough to survive pull of tides). As a result there is a large accumulation of dead plant material.
The animal community of the thatch is a mixture of terrestrial and aquatic species (e.g., plant hoppers and amphipods). The fact that the marshland is subjected to periods of flooding and drainage creates problems for both groups. The terrestrial species migrate to higher ground to avoid flooding and the aquatic ones must stay close to the ground surface to avoid desiccation at low tide. Although these animals live in close proximity to one another, the climate that these animals are exposed to may be very different. Different microclimates can be observed within the thatch. The relative humidity and temperature are both high close to the ground and decrease as the distance from the ground is increased.
Back to Tidal Marsh Fieldtrip Index Page