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THROPHIC RELATIONSHIPS IN WETLAND ECOSYSTEM

Presentation by

Livi Wilson and Jitendra Kumar

College of Fisheries, KVAFSU, Mangalore, Karnataka

jitenderanduat@gmail.com

 

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TROPHIC RELATIONSHIPS

The study of the structure of feeding relationships among organisms in an ecosystem

Feeding or trophic relationships can be represented as a

food web food chain.

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Food webs depict trophic links between all species sampled in a habitat

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food chains simplify this complexity into linear arrays of interactions among trophic levels

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FOOD WEBS IN SPECIFIC WETLAND TYPES 1.SALT MARSH

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Producers in a salt marsh include marsh grasses, Spartina Juncus Algae various other salt tolerant plants

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THE CONSUMERS COME IN SEVERAL CATEGORIES ACCORDING TO THEIR PREFERRED HABITAT.

a. Aerial Habitat--- above the substrate, not that in the air necessarily

. Consumers --- spiders and insects that live on plant leaves,

periwinkle snails that travel up and down plants,

o marsh crabs.

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B. BENTHIC HABITAT

Detrital food web < 10% of the above ground primary

productivity in a saltmarsh actually gets grazed,. Most plant biomass dies and decays and is passed through the detrital food web

consumers --- bacteria and fungi. These are then consumed by the smallest

animals—worms, copepods, rotifers, larval stages of benthic invertebrates, in other words, plankton.

The bigger benthic invertebrates are either scavengers (crabs, snails) or filterers (oysters, mussels

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C. AQUATIC HABITAT

overlaps with the benthic habitat, Consumers --- vertebrates.

There are several species of resident fish such as silversides, killifish, and mummichogs

In fact about 90% of the commercially important fish and shellfish in the southeast Atlantic and Gulf coasts depend on marshes.

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D. AVIAN CONSUMERS

includes many ducks and wading birds. Like the fish, many of these depend on

marshes along their migration routes and are not year round residents

E.MAMMALS

Raccoons and muskrats use salt marshes extensively as a food source

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MANGROVES

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2. MANGROVES

Because of the salt, there is less variety of PRODUCERS --- , but very high biomass because of the constant tidal influx of nutrients.

CONSUMERS--- wide variety of consumers present

especially filter feeders and detritivores. Barnacles and oysters filter feed and fiddler crabs scavenge, among lots of other invertebrates, especially juveniles. These juveniles include the commercially important spiny lobster, shrimp, mullet, and tarpon. These all provide food for a vast array of wading birds.

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3. FRESHWATER MARSHES

Reed grasses, cattails, rice, sedges, and ragweed are common to most temperate freshwater marshes, although distribution varies with latitude.

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wetlands that are the most affected by "alien species,"

Eg:The water hyacinth, is a trouble maker, it is very good at water filtering and then

holding onto the excess nutrients or chemicals. Thus it's often suggested as a valuable addition to natural wastewater treatment programs

CONSUMERS---The most abundant invertebrates are true flies, including mosquitoes.

With a high diversity of invertebrates there is a high diversity of birds

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PEATLANDS

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PEATLANDS

The dominant plant ---Sphagnum moss. It grows in cushionlike spongy mats with very high water content.

Sphagnum moss can hold 15-23 times its dry weight in water. The moss only grows actively at the surface, and the lower layers die off and decompose into peat

. Other plants may include heathers, cranberry, blueberry, some pines, spruce, and tamarack trees

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Peatlands ---wetlands having the lowest productivity

lowest nutrient levels .

hence several carnivorous plants are found here. They get their extra nutrients from insects.

These include pitcher plants, sundews, and venus flytraps.

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CONSUMERS Animal density is fairly low

because they are acidic and not much eats moss. They do serve as trails and shelters for large mammals.

Lots of birds pass through these areas on their migration routes

: sandhill cranes, short-eared and great gray owls, sharp-tailed sparrow.

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SOUTHERN DEEPWATER SWAMPS

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. SOUTHERN DEEPWATER SWAMPS

Cypress and tupelo trees dominate these ecosystems

There is a high diversity and high biomass oƒ invertebrates which depend on the abundant detritus available. Once again, this is the major source of nutrients for the food web

Reptiles and amphibians are quite diverse because they can adapt to changing flood levels

Alligators are common

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RIPARIAN WETLANDS

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. RIPARIAN WETLANDS

. predominance of woody plants

shade the water, stabilize the bank, and produce leaf litter

this directly supports aquatic species plus those that live on them

. corridors for dispersal and migration

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REFERENCES

Ecology and Food Webs in Wetlands (The introductory material on general

ecology and food webs is mostly from: Caduto, M.J. 1985. Pond and Brook. Hanover,

N.H.: University Press of New England. 276p.)

http://www.answers.com/topic/trophic-ecology#ixzz1cZ

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THANK YOU