Title: Ecological Sampling In Forest Research Institute Malaysia (FRIM), Selangor Objective: To carry out a study on the ecology of the habitat of FRIM
Experiment on abiotic factors
A. Experiment to analyze the composition of soil by sedimentation method Introduction:
Soil is a mixture of soil particles, mineral salts, soil water, soil air, organic matter or humus and living organisms. Some of the common organisms in soil are insects, earthworms and microorganisms such as bacteria and fungi. Soil particles originate from the weathering of rocks. These particles are classified based on their sizes. Clay particles give a large surface area due to the small size. They also form colloids in water which enable them to bind to many ions comprising a part of plant nutrition which is essential for plant growth.
Table 1 – Types of soil particles and their average diameter Types of soil particle Average diameter/ mm
Gravel >2
Coarse sand 0.2 – 2.0
Fine sand 0.02 – 0.2
Silt 0.002 – 0.02
Clay <0.002
Sedimentation is the tendency for particles in homogeneous suspension to settle out of the liquid until they come to rest against a barrier, forming a layer. Sedimentation is the result of forces such as gravity, centrifugal, acceleration or electromagnetism acting on the particles and causes movement of the particles. Sedimentation can vary in scale, ranging from large rocks in flowing water to suspensions of dust or pollen grains to cellular suspensions such as the blood to solutions of single molecules like proteins and peptides. Sediment is a naturally occurring matter that is broken down into smaller particles from big particles by weathering or erosion, and subsequently transported by fluid movement or forces like wind, water, gravity and so on.
Problem Statement: What is the composition of soil sample collected from FRIM? Apparatus: Measuring cylinder, spade
Materials: Water Procedure:
1. A sample of soil is put in a 500cm3 measuring cylinder and water is added to it until it is about ¾ full. 2. The cylinder is shaken vigorously and left aside for the soil to settle down in layers. This process is
Results:
Table 2 – Depth of layer and percentage of each type of soil
Type of Soil Depth of layer / mm Percentage / %
Quadrat A Quadrat B Quadrat C Average
Gravel/ Coarse sand 50 70 40 53.3 12.1
Fine sand 0 0 70 23.3 5.3
Silt 50 40 50 46.7 10.6
Clay 260 390 300 317.7 72.0
Table 3 – Classification of soil according to the proportion of the different soil particles Type of soil Coarse sand/% Fine sand/% Silt/% Clay/%
Sandy soil 67 18 6 9
Loam 27 32 21 20
Clay 1 9 22 68
Thus, the sampled soil is clay.
Discussion:
Based on the results, the soil in FRIM is clay as the proportion of all 4 types of soil particles are the closest to the standard proportion of clay. Clay can hold more water compared to loam and sandy soil so the water content of clay is the highest among the three types of soils. This ensures enough water for the uptake of plants to carry out various living processes such as transpiration and photosynthesis. Clay is also rich in various ions which are an essential part for plant nutrition. The ions are either bound to the clay particles or are dissolved in the water held by clay. Some clay particles are suspended in the water to form a cloudy suspension no matter how long the mixture is allowed to settle as the particles are too light. Humus, organic matter which is less dense as water floats on the water surface instead, appearing as a layer of dark organic debris.
An experimental precaution taken in this experiment is that the measuring cylinder is shaken vigorously to ensure that none of the soil particles are stuck to the wall of the measuring cylinder and is not dispersed. One limitation in this experiment is that there is sure to be some soil particles suspended in the water no matter how long it is left to settle. One possible source of error is that there may be an error in determining the depth of the soil layers such as parallax error where the eye is not placed perpendicularly to the scale of reading. However, the experiment is still deemed valid and reliable as the volume of the suspended soil particles is very low and so, does not affect the depth significantly. The experiment is also repeated 2 times to ensure the reliability.
B. Experiment to identify the soluble salts present in the soil sample Introduction:
Mineral salts are actually ionic compounds dissolved in soil water. Inorganic salts in the soil come from the weathering of rock containing these salts. Examples of inorganic salts are nitrates, sulphates, chlorides and carbonates. The sources of organic salts in soil are the excretory products of the organisms or the decomposition of dead organisms by microorganisms. Many salts are the macronutrients and micronutrients for healthy plant growth which are required in large and small amounts respectively. Only soluble salts are available for uptake by plants so insoluble salts are not investigated in this experiment.
Problem statement: What are the soluble salts present in the soil sample collected? Apparatus: Conical flasks with stoppers, filter funnel, test tubes
Materials: Sampled soil, distilled water, filter paper, cold iron (II) sulphate solution, concentrated sulphuric acid, and silver nitrate solution.
Procedure:
1. An equal volume of soil sample and distilled water is mixed in a stoppered conical flask and is shaken vigorously.
2. The mixture is filtered to collect a clear filtrate.
3. Different types of reagents are added to a small amount of filtrate in separate test tubes and the results are observed.
4. Steps 1 to 3 are repeated using another soil sample collected from another quadrat. The results are recorded.
Results:
Table 4 – Reagents added to the soil samples and the interpretations based on observations
Reagent added Observation Interpretation [salts
present]
Quadrat A Quadrat B
Cold FeSO4 solution followed by a few drops of conc. H2SO4
The mixture becomes warm.
The mixture becomes warm.
Nitrates are present. Silver nitrate solution No change is
observed.
No change is observed.
Chlorides are absent.
Discussion:
From the results, it can be inferred that both soil samples contain nitrates although no brown rings can be observed in the mixtures. This is because the reactions do occur as the reaction is exothermic and thus the heat released that makes the mixtures warm. Nitrates are the main source of nitrogen uptake by plants. Nitrogen is the basic element in all proteins as amino acid monomers of proteins contain nitrogen atoms in their amine groups. Nitrogen is also closely related to chlorophyll synthesis as chlorophyll also contains nitrogen. However, the soil does not contain chlorides since no change is observed when silver nitrate solution is added to the filtrates.
One of the limitations in this experiment is that the reagents needed to identify other ions are not provided. For example, barium chloride solution which is used to detect the sulphates is not provided. Dilute nitric acid and ammonium molybdate solution which are used to detect phosphates are not provided too. Another limitation is that the tests are only carried out 2 times due to time constraint.
One source of error is that the concentrated sulphuric acid is not dropped into the test tube drop by drop to ensure the appearance of the brown ring. However, the test is still considered valid and reliable as the mixture produces heat as a proof that there is a reaction occurring. The tests are also repeated twice to eliminate any anomalies. Therefore an improvement can be made such that the sulphuric acid is dropped drop by drop into the test tubes with shaking the test tubes.
Conclusion: The sampled soil contains nitrate salts but not chloride salts.
C. Experiment to investigate the volume of air in a soil sample Introduction:
The volume of soil air is an important abiotic factor in the ecology as it determines the aeration. Sandy soil has good aeration. This is because the large sand particles fit together loosely and large air spaces are present between them. Clay soil has poor aeration. This is because the small clay particles clump together closely and the air spaces between them are very small. These air spaces are filled with water easily and become water-logged and as a result, soil air is driven out.
Soil air is very important as it allows the aerobic respiration of the plant roots and other organisms living in the soil. The oxygen content in water-logged soil is very low. This affects the growth of plant roots. It also inhibits the decomposition of humus to form mineral salts. This can lead to plant malnutrition and undesirable changes in soil pH. It also causes the denitrifying bacteria to remove the useful nitrates from soil.
Problem statement: What is the volume of air in the soil sample collected? Apparatus: Empty tin, measuring cylinder, 2-L beaker, marker pen, glass rod Materials: Water
Procedure:
1. A small empty tin is put in a 2-L beaker which has been filled with about 1.5L of water. The water level on the side of the beaker is marked as X.
2. The tin filled with water is carefully removed and its content is poured into a measuring cylinder to find the volume of the tin, V1 ml.
3. Several holes are bore at the bottom of the tin. It is driven with its open end down into soil until its bottom is at the soil surface. The tin is then carefully dug out and the surplus soil is leveled off at its open end.
4. This tin of soil is then carefully lowered into the beaker. A glass rod is used to stir the soil out of the tin to allow all the air to escape until no more bubbles are released.
6. Water from the measuring cylinder is added into the beaker until water level rises from Y back to X. The volume of water added is taken as V2 ml which is equal to the volume of air present in [displaced from] soil.
7. The results are recorded.
8. Steps 1 to 8 are repeated using soil samples from 2 other quadrats.
Figure 1: Experiment to find the volume of air in a soil sample Results:
Percentage of air in soil = volume of air in soil volume of soil =
V2 V1
× 100
Table 5 – Experimental values of X, Y, V1 and V2 (refer procedure) in respective soil samples
Sampled soil X Y V1 V2
Quadrat A 1500 1350 400 150
Quadrat B 1500 1300 400 200
Average 1500 1325 400 175
Percentage of air in soil = 175
Discussion:
Based on the results, there is 43.75% of air in the soil, which means nearly half of the volume of the soil samples consists of air. This means that the soil is quite loose as air is able to diffuse into the spaces in the soil. This condition is good for the plants as the aerobic respiration of the roots of the plants can be carried out easily. Oxygen diffuses quickly into the soil while carbon dioxide diffuses out to the atmosphere as quickly too. Loose soil also allows excess water to be drained faster so the plant roots will not be waterlogged easily. This benefits the plant growth greatly.
Some experimental precautions are exercised in this experiment. The tin containing the water is removed as carefully as possible to prevent the water from spilling, causing the value of Y to be higher than the actual value, making the results inaccurate. The tin is carefully dug out from the soil as well to prevent the soil dug out from falling back to the ground which can cause the value of Y to be lower than the actual value.
The limitation of this experiment is that the experiment is only repeated once due to time constraint. One possible source of error is that some gases in air are water-soluble. For example, oxygen can dissolve in water as dissolved oxygen while carbon dioxide is slightly soluble in water. As such, some of the gases which are supposed to be liberated as air bubbles are dissolved in water instead, causing the calculated percentage of air in the soil to be slightly lower than the actual value. Another possible error is parallax error caused by the observer not placing the eye perpendicular to the scale of reading. The soil may also have been dug out before this experiment is carried out, causing the soil to become loose, thus enabling more spaces for the air to diffuse into.
Conclusion: 43.75% of air is present in the sampled soil. D. Experiment to determine the pH of soil sample Problem statement: What is the pH of the sampled area? Introduction:
The soil pH is a measure of the degree of acidity or alkalinity in soils. pH is defined as the negative logarithm to the base 10 of the concentration of hydrogen ions (H+) in solution. It ranges from 0 to 14. A pH of below 7 is acidic; a pH of 7 is neutral; a pH of above 7 is basic or alkaline. Soil pH is considered a master variable in soils as many chemical processes in soil depends on the pH. The salts in soil affect the pH value of soil. Acidic soil is usually rich in carbonic acid caused by carbon dioxide dissolving in soil water and other organic acids from the aforementioned organic sources. Soil rich in calcium and sodium salts is alkaline in nature.
The pH value of soil affects plant growth by causing some salts to become insoluble in water. This is because the main source of plant mineral uptake is soluble salts so the insoluble salts are not available for absorption by plants. The optimum pH range for most plants is between 6 and 7.5 although many plants have adaptations that allow them to survive at pH values outside this range.
Apparatus: Conical flask
Procedure:
1. An equal volume of soil sample and distilled water is mixed in a stoppered conical flask and is shaken vigorously.
2. The mixture is filtered to collect a clear filtrate.
3. A universal indicator paper is dipped into the above soil filtrate. The pH of the soil filtrate is read off from the colour chart.
Table 6 – Colour chart for universal indicator paper pH range Colour 0-3 Red 3-6 Orange/ yellow 7 Green 8-11 Blue 11-14 Violet
4. Steps 1 to 3 are repeated using soil sample collected from 2 other quadrats. Results:
Table 7 – pH of soil samples in different quadrats Soil filtrate pH
Quadrat A 4
Quadrat B 4
Quadrat C 4
Average 4
Therefore the pH of the sampled area is 4. Discussion:
According to the results, the pH of the sampled soil is 4, which is slightly acidic. The acidity of the soil is due to the presence of ions such as nitrates, sulphates, carbonates and phosphates which dissolve in water to form very dilute acid solutions such as nitric acid, sulphuric acid, carbonic acid and phosphoric acid. The diluted acid solution inhibits the growth of certain microorganisms which may be pathogenic to the plants. The slightly acidic condition is also suitable for the plants as soil that is too acidic will cause the leaching of mineral ions and corrode the roots of the plants.
One of the possible sources of error is the mistake in determining the colour of the universal indicator paper. For example, pH 8 may be mistaken as pH 9 as the colours on the chart are both in the range of blue. Another possible error is that the reading is read when the colour change is still ongoing, causing the value to be higher or lower than the actual pH value.
Conclusion: The pH of the soil sampled in FRIM is 4, so the soil is acidic soil. E. Experiment to check the humidity of the sampled area
Humidity refers to the water vapour and also its measurements in the air. Technically, humid air is a mixture of water vapour and other components of air such as oxygen, carbon dioxide and nitrogen, and not ‘moist air’. Relative humidity investigated in this experiment is defined in terms of the water content of the air which is a mixture of many gases, including water. Humidity is measured using a hygrometer or psychrometer. Humidity is among the basic abiotic factors that determine the survival of flora and fauna in any given environment. Humidity is also closely related to transpiration in plants and the rate of transpiration, thus affecting the plant biodiversity which in turn affects the animal biodiversity.
Problem statement: What is the humidity of the sampled area? Apparatus: Whirling hygrometer
Material: Water
Procedure:
1. A spot is randomly selected in a quadrat.
2. The whirling hygrometer is whirled for 60 seconds.
3. The reading of the wet-bulb thermometer is observed and recorded. 4. The reading of the dry-bulb thermometer is observed and recorded.
5. The relative humidity is determined from the value on the whirling hygrometer chart that corresponds with the readings.
6. Steps 1 to 5 are repeated at spots selected in 2 other quadrats.
Results:
Table 8 – Wet bulb temperature and dry bulb temperature in different quadrats Quadrat Wet bulb temperature/ °C Dry bulb temperature/ °C
A 25.0 25.5
B 24.5 25.2
C 25.0 25.5
Wet bulb depression
= Average dry bulb temperature – Average wet bulb temperature = 25.4 – 24.8
= 0.6 ≈ 0.5
Percentage of humidity based on the values corresponding to the wet bulb depression= 96% Discussion:
In this experiment, the humidity of the sampled area is 96%. The measure of humidity is in percentage as humidity is qualitative analysis and so there is no unit for the measurement of humidity. The humidity of FRIM is very high as it is a tropical rainforest. Tropical rainforests have high humidity due to the high transpiration rate of the forest plants. Besides, the climate around tropical rainforests has a high rainfall rate. One limitation in this experiment is that the experiment is done on a rainy day where the humidity is sure to be higher than usual. One possible source of error is that the wet bulb temperature and dry bulb temperature is not read immediately. This is because the thermometers are very sensitive and the readings may have fluctuated before they can be read. This experiment is reliable as it is done 3 times in different quadrats of the same area and no anomalous results are obtained.
Conclusion: The percentage humidity of FRIM is 96% as it is a tropical rainforest.
F. Experiment to measure the temperature of the sampled area Introduction:
Temperature is a physical property of matter that quantifies the amount of heat contained in an object. Temperature is a vital measurement applied in all fields of natural science such as physics, geology, chemistry, atmospheric sciences and biology. Temperature is measured with a thermometer, but in this experiment, a hygrometer is as it also has a dry-bulb thermometer which is equivalent to the usual thermometer.
Atmospheric temperature is a measure of temperature of the Earth’s atmosphere at different heights. It is affected by many factors such as solar radiation, humidity and altitude. The type of biome present at any geographical location is the master variable that affects the atmospheric temperature range.
Problem statement: What is the temperature of the sampled area? Apparatus: Hygrometer
Procedure:
1. A spot is randomly selected in the quadrat area. 2. The whirling hygrometer is whirled for 60 seconds.
3. The reading of the dry-bulb thermometer is observed and recorded. 4. Steps 1 to 3 are repeated at spots selected in 2 other quadrats. Results:
Dry-bulb temperature= surrounding temperature Table 9 – Dry bulb temperature in different quadrats Quadrat Dry bulb temperature/ °C
A 25.5
B 25.2
C 25.5
Average 25.4
Discussion:
Based on the results, the surrounding temperature of the sampled area is 25.4 °C, which is almost equivalent to the room temperature. This provides a warm environment which is suitable for the enzymatic and metabolic reactions of the living organisms in the habitat as too high the temperature will cause the enzymes to be denatured while a cold environment will cause the enzymes to be inactive.
One limitation in this experiment is that the experiment is done on a rainy day where the temperature is sure to be lower than usual. One possible source of error is that the dry bulb temperature is not read immediately. This is because the thermometers are very sensitive and the readings may have fluctuated before they can be read. This experiment is reliable as it is done 3 times in different quadrats of the same area and no anomalous results are obtained. The experiment is also carried out at the same time to eliminate the influence caused by the time of day and cloud cover.
Conclusion: The percentage humidity of FRIM is 25.4 °C and is similar to that of tropical rainforest. Thus, FRIM is a tropical rainforest.
Experiment on biotic factor
G. Experiment to investigate the biodiversity of the sampled area by ecological sampling Introduction:
Ecological sampling is a technique used to quantify the biodiversity of a particular habitat. Ecological sampling is used instead of counting the number of each and every single individual in a habitat for a few reasons. One reason is that counting the number of organisms in the whole habitat is impractical as it takes an extremely long time while is still unable to guarantee the reliability of the results, as the number of
individuals keep changing due to factors like migration, predation, diseases and so on. By taking a sample, the number of individuals of the species investigated is counted in smaller areas chosen randomly in the same habitat. The values are then multiplied and are used to estimate a value for the whole habitat. In both ways the reliability are almost the same but the latter method provides a more systematic and useful data while minimizing the effort required to collect the data compared to the first method.
The sampling technique used in this experiment is quadrat sampling. Quadrats are used to sample plant communities and slow-moving or stationary animals. In this experiment, a frame quadrat is made by tying nylon strings around a randomly chosen area in a square and subdivided into 4 smaller squares of the same dimensions. This is because throwing frame quadrats can be dangerous as the sampled area has many trees and obstructions.
There are several methods available to measure the abundance or distribution of a species. One such method is calculating the species density. Using this method, the number of individuals in each quadrat is calculated and the mean is taken to give the number per unit area, in this case, per square meter. However, this method cannot be used to calculate the density of individual plants that are indistinguishable, such as grasses and moss. The frequency of a species, i.e. the number or percentage of sampling units in which a particular species occurs can also be calculated. When this method is employed, consistency needs to be practiced when determining the presence or absence in a sampling unit. For example, only plants that are rooted in the quadrat are counted.
Percentage coverage is used to calculate the percentage of a landscape covered by a species within the sampling unit. This method is used to estimate the population of species in which individuals are hardly distinguished. The number of squares within the quadrat that the plant completely covers is counted, followed by those partly covered and the number of full squares that would be completely covered by that species is estimated. Quadrat sampling cannot be used to estimate animal populations as they are mobile, and so will not stay in the quadrat only. There are many ways to catch small animal samples without hurting them. For example, pitfall trap can be used to sample arthropods. Organisms hiding in the soil or leaf litter can be collected using a Tullgren funnel. Insects can be collected with a pooter. Animals living in low-growing vegetation can be collected with a sweep net. Other common ways include the capture-recapture technique, anaesthetic fogging and beat-and-collect technique.
Problem statement: What is the variety of the species and their population size in the sampled area?
Apparatus: Scissors, wooden stakes, measuring tapes Materials: Nylon string, ropes
Procedure:
1. Nylon strings are tied around a square area of 20 m× 20 m measured with a measuring tape, using surrounding trees or wooden stakes where necessary.
2. The square area is further divided into 4 quadrats of 10 m× 10m each using ropes.
3. Any plant or animal species in any quadrat is identified and the number of individuals of each species is counted.
4. Step 3 is repeated in all other quadrats and the results are tabulated. Results:
Species identified:
Figure 4 – Species C (Camphor tree, Scientific name: Dryobalanops
aromatica)
Figure 2 – Species A Figure 3 – Species B (Fishtail palm of genus Caryota) Table 10 – Number of individuals of each species in each quadrat
Species Quadrat A B C D Total A 20 38 42 7 107 B 4 4 14 5 27 C (Dryobalanops aromatica) 10 70 11 21 112
Species density = Total number of individuals of a species in all quadrats number of quadrats × a quadrat area
Species frequency =Number of quadrats containing a species
number of quadrats × 100 Percentage coverage = Areas covered by a species in all quadrats (m
2)
Abundance = Total number of a particular species
Total number of all species × 100
Table 11 – Species density, species frequency and the abundance of the species identified Species Species density/ individuals per m2(m-2) Species frequency/ % Abundance/ %
A 107 4 × 10 × 10= 0.2675 4 4 × 100 = 100 107 246 × 100 = 43.5 B 27 4 × 10 × 10= 0.0675 4 4 × 100 = 100 27 246 × 100 = 11.0 C 112 4 × 10 × 10= 0.2800 4 4 × 100 = 100 112 246 × 100 = 45.5
Bar Chart 1 – Species density of the species identified in the sampled area in FRIM
0 0.05 0.1 0.15 0.2 0.25 0.3
Species A Species B Species C
S pe cies de nsit y / indi viduals pe r m 2 (m -2 ) Species
Bar Chart 2 – Abundance of the species identified in the sampled area in FRIM
Discussion:
From the results, it can be seen that species C has the highest species density and abundance, meaning that species C is most densely populated in the sampled area. Species A has a similar but slightly lower species density and abundance as compared to species C. The species density and abundance of species B is the lowest, which are only about one-fourth of those of species A and C. Thus, it can be inferred that the biotic and abiotic factors in FRIM are more suitable for the survival of species A and C, so species A and C are selected for in this environment. They are able to adapt and reproduce, passing on the advantageous traits to the following generations. Conversely, species B is selected against in FRIM as it cannot adapt to the environment and cannot compete with the other two species.
0 5 10 15 20 25 30 35 40 45 50
Species A Species B Species C
Abunda
nc
e/%
Species
Species B or fishtail palm, is from the genus of palm trees, Caryota. The name of fishtail palm comes from the shape of their leaves which resembles fish tails. About 13 species in this genus is native to Asia and the South Pacific. These palm species generally grow in mountainous areas and are adapted to Mediterranean, subtropical and tropical climates. Species C (Camphor tree, known as ‘Pokok kapur’ in Malay) with scientific name Dryobalanops aromatica, is a species in the Dipterocarpaceae family. Its resin, also known as ‘dammar’, is aromatic. It is a large emergent tree found in mixed dipterocarp forests in Peninsula Malaysia, Sumatra and Borneo.
The biodiversity of the sampled area in FRIM is low as there are a low number of different species found and a low number of the individuals of each species per square metre. This shows small population sizes of the species identified. Species A and C are dominant over species B in the sampled area.
One of the experimental precautions taken in this experiment is that the quadrats are made sure to be perfect squares. The measuring tapes are placed perpendicularly to each other. When subdividing the quadrat into 4 equivalent squares, the nylon strings forming the outer boundaries are made sure to not be pulled inwards, causing the shape of the quadrat to be deformed.
One of the limitations in this experiment is a lack of advanced laboratory apparatus needed to identify the species accurately. Students can only identify the species from their morphology as molecular phylogeny cannot be carried out to analyze the physiology of the species. Some individuals are closely-related but are from distinct species so their morphology is similar. This is a possible source of error as it can cause mistakes in counting the number of individuals of a particular species as the students are unable to differentiate them as 2 species. Besides, the quadrat may not be made properly as well, causing the quadrat to look like a deformed square.
The percentage coverage of the species is not calculated in this experiment as the individual plants can be distinguished easily. This experiment is deemed valid and reliable as it is counted by many students and each of them counted the same number of individuals of each species in each quadrat so the results is unbiased.
Conclusion:
The biodiversity of the sampled area in FRIM is low as the number and the sizes of the populations are small. Species A and C is dominant over species B but neither species A nor C is dominant over each other so there is no dominant species in FRIM.
Improvements and modifications:
More apparatus and materials can be provided so that the delay due to shortage of apparatus can be reduced. With the availability of more tools, more types of experiment that cannot be carried out previously due to a lack of suitable tools can now be done. More time can be provided to carry out the experiments so that more repetitions or more types of experiments can be carried out.
Further Work:
More abiotic and biotic factors can be investigated. Examples of other abiotic factors that can be taken into consideration are gradient (angle of slope), aspect, light intensity, conductivity of soil water, soil organic matter content, soil water content and air movement. Examples of other biotic factors that can be investigated include predation, competition and territory.
Safety Precaution:
Suitable attire such as sport shoes to avoid accidents. Collared, long-sleeved shirts, long pants and insect repellents are also advised to minimize exposure to any harmful creatures and to keep them away. Care is taken when moving in the sampled area to prevent falls as the landscape may be inclined or slippery. Glassware is handled with care to avoid breakage. If any glassware is accidentally broken, carefully put the pieces into several layers of plastic bag. Sharp apparatus such as the spades are also handled carefully to avoid causing injuries. When not in use, the sharp edges should be pointed away from other people; the apparatus is kept immediately after using as well. After carrying out the experiments, the hands should be washed with clean water sources and soap if possible to avoid bacterial infection. Animals and plants that are not known are avoided to prevent injuries or other unwanted effects such as bites, poisoning and so on. The lecturer should be alerted in the case of injuries or discomfort, such as cuts, insect bites, itchy rashes and so on.
Reference:
1. Wikipedia, 2012, Sedimentation, http://en.wikipedia.org/wiki/Sedimentation 2. Wikipedia, 2012, Sediment, http://en.wikipedia.org/wiki/Sediment
3. Wikipedia, 2012, Soil pH, http://en.wikipedia.org/wiki/Soil_pH 4. Wikipedia, 2012, Humidity, http://en.wikipedia.org/wiki/Humidity 5. Wikipedia, 2012, Temperature, http://en.wikipedia.org/wiki/Temperature
6. Wikipedia, 2012, Atmospheric temperature, http://en.wikipedia.org/wiki/Atmospheric_temperature 7. Wikipedia, 2012, Caryota, http://en.wikipedia.org/wiki/Caryota
