Field Trip Fresh Water

G3 Members :

Ivan Lee

Timmy Lam

Frank Cheng

Chris Chan

Aims• To determinate the

Physical factors of the stream. (The living condition of the Aquatic animals)

Biological factors of the stream. ( Aquatic animals, Soil)

Background Information

Venue : Tai Po Kau Nature Reserve

Date : 30th May, 2003

Group : G3

Weather condition : Sunny

Map

Map of the stream

Tree

Transect Line

Water

Ecological Techniques

Temperature Using the Thermometer

Wind Speed Using the anemometer

Water Speed Using the floating object

Light Using the Light Probe

pH Using the pH papers

Anemometer

•To determine the wind speed.

Transect Line

Transect Line

Quadrat

Transect Line?

• It is a method to identify the status of a plant community in a vegetation.

• It uses a rope marked at 0.5m or 1m intervals, and we will record the plants touching the intervals.

A Quadrat frame

1 meter ( internal dimension )

Quadrat frame = Bird Cage

A Quadrat frame

Aquatic Animals

The aquatic animals are active.

Like a little kid living on the ground.

Have home / Flat or community.

Let see what their home look like

Aquatic animals = A little kid ? ?

Fishes FoundThe fishes are usually find under the rock as they want to find some protection.

Fishes FoundThe fishes are usually found :

• Lower light intensity.

• Shallow region

Fishes are more favor in such conditions

Measuring

Fishes

High light intensity

Come on !!

Measuring

Transect Line

Smooth Rock

Measuring the Transect line and the depth.

Measuring

InvestigationMicroscope

Soil

Investigation

Fishes

* New Home

Yes ! I can see it !!

Soil InformationType of

SoilSoil information

Air Spaces

Minerals Compacted

Sandy soil

Loam soil Intermediate Intermediate Intermediate

Clay soil

Soil investigation

Sandy soil

Clay soil

Loam soil

Food WebLight

Plants

Fishes

Sun energy

Decomposers

Chemical energy

Sun

Respiration

Dead

curve

0

10

20

30

40

50

60

70

Distance across

stream (m)

Depth of

water (cm)

Topography

curve 40.6 68.6 61 40.6 43.2 40.6 40.6 35.6 20.3 10.1

Physical FactorsLight Intensity Above water

Surface390 X 100 Lux

Temperature Underneath 21.5°C

Mid-depth 21°C

Bottom 21°C

Current Speed (m/s)

Speed = Distance / Time

[ Assume the acceleration is constant.]

0.0489m/s

RockRock under water containing:

Calcium, silicon, Aluminum.

Mosses

Bryophytes

Stems and leaves

No true roots.

The leaves are arranged spirally

Contain chlorophyll.

Have Alternation of Generations

Discussion (Limiting Factors)

High Temperature in summer

Affect the dissolving of gases

Increasing rate of evaporation

Animals will go away

Discussion (Limiting Factors)

Rock trap dead and decaying organisms.

This attracts the scavenging animals.

Attach on the rock.

Decomposer. Maintained food cycle.

Presented by G3