A Local Ecosystem
A mangrove is a tree, shrub, palm or ground fern, generally exceeding the height of one and a half metres. They normally grow above mean (average) sea level in intertidal zones of marine coastal environments as well as estuarine margins. A mangrove also refers to the tidal habitat comprising of such trees and shrubs. Australian mangrove systems are highly effecting by human presence and, thus can have a negative impact on the local ecosystem. Australian mangroves, although they may not seem like much, play a vital role, and are an extremely important ecosystem. Mangroves, or intertidal forests are able to prevent erosion and stabilize sediment because of their ‘breathing roots’, as well as this they also filter run-off from the land to keep the water of other more commercialized placed clear. These are just a few reason of why the mangrove ecosystem is of importance so we are able to maintain the biotic features that a present. The purpose of the investigation is to estimate population and distribution of mangroves, and nippers as well as recording salinity and temperatures of the water in this ecosystem. Human impacts will also be investigated, as it has a drastic effect on Method:
1. Measure abiotic features including salinity, temperature and dissolved oxygen. This can be done using a datalogger with a temperature and a salinity probe attached and an oxygen meter. Record salinity, temperature and dissolved oxygen at three separate sites in the mangrove ecosystem. Focusing on one of the three sites, record the temperature over the course of 10 hours. 2. Analyze the flow over energy and matter in a mangrove swamp.
1. Estimate the size of a plant and animal population.
Plant- To estimate the population of the mangrove tree, two methods are used. First being a transect. A transect is performed by measuring a line (20 metres or so) and counting the amount of the species that lie on the line. The second being a quadrat. The quadrat is performed A 1 meter square quadrat was placed randomly in an area containing juvenile mangrove trees. A stick was thrown over the shoulder and where the stick landed was the bottom corner of the quadrat. The number of mangrove seedlings in the quadrat was counted. Animals- The animal to be investigated is the nipper; it is fairly obvious to see the nipper holes at low tide. By using the random quadrat method take 10 measurements then calculate the average number of holes per square meter. The average is then multiplied by the area covered with nipper holes. 2. Look at the role of decomposers in the ecosystem. Record results. 3. Observe the adaptations in the organisms present.
4. Observe the relations of the organisms in the ecosystem 5. Identify producer’s consumers and decomposers and construct food chains and food webs. 6. Look at the predator/prey relationships.
7. Analyze the human impact in the area.
Site| Temp oC| Salinity (ppt)| pH| Dissolved O2|
1| 16| 24.2| 8.3| 61%|
2| 17| 3.5.| 9.2| 47%|
3| 15.5| 0.2| 7.4| 75%|
Temperature (over 10 hours)
Time| Temp oC|
Abundance of Nippers
Quadrat number| Nipper Holes|
Producers, consumers and decomposers in Mangrove Ecosystem
Producers| Consumers| Decomposers|
Mangrove| Nipper| Bacteria|
Seagrass Zostera| Leatherjacket| Fungus|
Sargassum| Bream| |
Phytoplankton| Whiting| |
| Heron| |
| Cormorant| |
| Ibis| |
| Oyster| |
| Soldier crab| |