Mangrove is a general term that covers trees that are able to withstand the conditions found in shallow intertidal areas. The plants called mangroves come from a variety of plant families. It is their ability to withstand regular flooding with fresh and salt water that is their defining quality. Mangroves are usually found in sheltered embayments. The trees must be able to withstand being submerged twice a day by tidal saltwater. Evaporation during the intertidal period can cause the salinity of the water to rise well above that of seawater. During periods of rain the mangroves at low tide are exposed to salinity levels approaching that of freshwater. The soil that the mangroves grow in may be sand but is often a rich mud high in nutrients but lacking in oxygen (anaerobic). This mud is responsible for the smell often associated with mangrove swamps. Mangroves have specially adapted aerial and salt filtering roots and salt excreting leaves that enable them to occupy the fluctuating wetlands that other plants cannot occupy.
Measuring Abiotic Factors
The term abiotic refers to the non-living or physical components of an ecosystem. We are going to look at three abiotic factors:In any ecosystem the abiotic factors are not identical over the whole area. The tide has a lot to do with the distribution of plants in the ecosystem. Mangroves occur in areas that are inundated daily. Further away from the water in areas that only covered with water during the highest high tides are found saltmarsh plants. In the areas that are covered with water most of the time are the seagrasses.
Salinity
Temperature
Oxygen
To do this we are going to use two pieces of equipment:
- a datalogger with a temperature and a salinity probe attached
- an oxygen meter
Go to one of these abiotic features now.
Salinity Temperature Oxygen
Flow of energy and matter in a mangrove swamp
Energy is used for all the processes that occur in organisms. Energy is not recycled in the environment it is stored, used or is lost as heat. It flows through the environment. The source of energy for the mangrove ecosystem is the sun. Plants use sunlight to provide energy for the process of photosynthesis. This energy is then passed through the food chain as organisms consume other organisms. At each step in the food chain there is a loss of energy as heat. If the organisms in an ecosystem do not use the available energy it is lost to the ecosystem.Matter on the other hand is recycled in the ecosystem. A carbon atom that is part of a mangrove tree leaf may fall to the ground and decay. This detritus may then be eaten by a crab. The crab converts the matter into its own body material which may then be eaten by a fish. An ibis then eats the fish. The carbon atom that was part of a mangrove may become part of a crab, a fish or a bird.
The mangrove ecosystem has a detrital food web. Many of the animals that live in this ecosystem consume detritus.
