map
Profile gradient
• Study distribution of organisms influenced by factors related to height • E.g. light intensity, wind exposure, wave action • Measured by 2 ranging poles, nylon thread and a spirit level • The poles held upright at Y’ and Y” on a slope • The thread attached at X’ and X” • Use the spirit level to find whether the stick is horizontal • Gradient= vertical distance/ horizontal distance gradient between Y’ and Y” = X”Y” - X’Y’ X’X”
Mangrove Plants
Aegiceras corniculatum 桐花樹
1.Short evergreen tree with flowers 2.Widely distributed at the outer fringe of mangroves 3.Veins of leaves are cleared than Kandelia candel 4.The branches are little bit red 5.Leaves have salt glands so salt secreted are often seen on the surface of leaves 6.Cable roots spread horizontally and laterally just below the soil surface to anchor the plant firmly 7.Have knee joint and prop root 8.Flowers open like a umbrella 9.Have droppers to produce seeds that germinate inside
Avicennia marina 白骨壤
1.Pioneers species of tree 2. In front of taller mangrove plants in sub-littoral zone 3. Have aerial roots which can grow even higher than the crown so that thy can still breathe at high tides 4. Cable root spread horizontally and laterally just below the soil surface to anchor the plant firmly 5. Leaves have salt glands so salt secreted are often seen on the surface of leaves 6. Back of the leaves can reflect sunlight 7. Leaves are thick and waxy 8. Tree bark is pale grey in colour
Kandelia candel 秋茄 ( 水筆仔 )
1. at the inner fringe of mangroves
2.prop roots → supply air to the underlying roots→ provide stability for the plant by broadening the base 3. knee joints →grow above the soil surface →gas exchange 4. large lenticles →↑efficiency of gas exchange
5.prevent salt from entering root xylem by active pump mechanism 6.thick cuticle,epidermal hairs and sunken stomata →reduce transpiration 7. Have droppers to produce seeds that germinate inside
Lumnitzera racemosa 欖李
1.locate near the coastal area 2.leaf facing upward 3. cleavage found in tip of the leaf 2.prevent salt from entering root xylem by active pump mechanism 3.store large amount of salts the leaves are shed when they are old , reducing the salt inside plants 4.prevent salt from entering root xylem by active pump mechanism
Bruguiera gymnorrhiza 木欖
Large leaves red stipe trunk branches flowers 1.develop branhed, looping aerialroots arising from the trunk and lower branches →trap mud during tidal movement →help to increase amount of soil
5.store large amount of salts the leaves are shed when they are old , reducing the salt inside plants
2. Have droppers to produce
seeds that germinate inside
3.knee joints →grow above the soil surface →gas exchange 4. large lenticles →↑efficiency of gas exchange
Mangrove Field Study
Quadrat • - a regular shape, usually a square (1M x 1M) • or rectangular, of known size, • inside where the no. of animals and plants are counted and identified.
Physical factors (at the 5 quadrats) • a. Use the thermometer to record the temperature in the air and under the canopy of plants. • b. Record the relative humidity by the Dry and wet bulb psychrometer. • c. Record the speed of wind by holding the hand-held wind meter against the wind. Note also the direction of the wind with the help of a compass. • d. Record the light intensity by means of an environmental comparator with light probe. • e. Record the soil pH by using the pH paper.
Method: Animal Sampling 1) Line Transect: Place 5 quadrats along the transect line at regular intervals
Method: Animal Sampling 2) Search for animals on each plant within the quadrat - Identify, count, and note the location of the animals on each plant 3) Record these in data sheet 4) Search for animals on surface of mud and under stones - Capture all the animals within the quadrat and place them on a plastic tray - Identify the animals, count the number per species
Method: Animal Sampling 5)Dig up the top 5 cm (hard soil) or 10cm (soft soil) of mud within quadrat by spade( 鏟子 ) 6) Place portions of mud in a plastic sieve. Put the sieve into a plastic bucket ( full of water) 7) Stir mud in the sieve by using trowel( 小鏟子 ) 8)Transfer the animals into the plastic tray. Identify, court and record them. 9) Release the animals 10)Repeat steps 1-9 at each quadrat
Data Treatment: Kite Diagram On the space below the profile, draw a kite diagram to show the distribution and abundance of animals.
-a line along which organism are counted and measured -clearly visualize the changes taking place along the line -to determine the distribution of organisms along a selected area -across area with transition in population and abiotic gradients -Line transect: selection of a straight line along the ground in the area of study -Belt transect: selection of a strip of terrain with a fixed width along the habitat
- selection of a straight line along the ground in the area of study to study the species touching the line Method to set up: 1. Use a nylon rope marked and numbered at 0.5m, or 1m intervals, all the way along its length, lay across the area you wish to study.
2. Unroll the transect line along the gradient identified.
3. The species touching the line may be recorded along the whole length of the line. The presence, or absence of species at each marked point is recorded. 4. When the slope along the transect line is measured as well, the results can then be inserted onto this profile.
-selection of a strip of terrain with a fixed width along the habitat
Method to set up: -Set up 2 straight lines parallel to each other (e.g. 0.5m/ 1m apart) OR -place quadrants continuously / in regular intervals along a transect line
result represents by kite diagram/ histogram A Kite Diagram
A Histogram
Mangrove The End