• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Population Ecology - Dandelions

Extracts from this document...


Estimating the size of a dandelion (Taraxacum Officinale) population using quadrat analysis Ashneet Singh 493629 Partners: Harsimar Virdi, Mohak Malik Mr. Crawford September 18, 2009 Purpose To estimate the population of dandelions on the school's football field. Introduction Succession is the process of the development of a sequence of communities over a period of time. There are many methods that are used in ecology to measure the population of a species. Collection of data in the case of immobile (stationary) species, such as the population of plants being studied for this investigation, was collected using line transects. These are analysis methods across a representative part of the habitat, along which quadrats are laid to cover a certain area for collecting population data. The dandelion population being studied is located in the school's soccer field, where some plants have been tempered with, due to mowing and excrements left by another species. Also, human impact (students that play in the fields) has also affected the growth of the population in various places. Variables Controlled - The size of the circular quadrat, meaning the hula-hoop, the day for the experiment, and the distance between each quadrat. Independent - The initial positioning of the quadrat from the base line (first quadrat) ...read more.


The locations with this entity had plants that were smaller than the locations without this entity. Data Processing and Calculations Calculations involving individual data: (Using Table 1) Average Number of Dandelion Plants = = = 20 � 1 dandelion plants/quadrat Area of Quadrat Uncertainty Area of hula-hoop = = ?(0.45 � 0.01m)2 = 0.6362 � 0.0283m2 = (*0.6362 = 0.0283m2 Area of Transect (Football field) Uncertainty = length * width = 75m � 1m * 50m � 1m = 3750 � 125m2 = (*3750 = 125m2 Average Population Density Uncertainty = = = 31.44 2.97 dandelion plants/m2 = (*31 = 2.97 dandelion plants/m2 Estimation of dandelion plant population in the transect Uncertainty = average population density * area of transect = 31.44 2.97 * 3750 125m2 = 117900 15068 dandelion plants/transect = (*117900 = 15068 dandelion plants/transect Calculaitons involving class data (Using Table 2): Table 3: Calculated values for data collected from the class Group number Average Population Density (Dandelion plants/m2) 1 38 3 2 36 3 3 33 3 4 19 2 5 31 3 6 28 3 7 33 3 Estimation of dandelion plant population in the transect (class data) Average Population Density of Class Total Population Size = = = 31.14 2.86 dandelion plants/m2 = Average Population Density of Class * area of transect = 31.14 2.86 * 3750 125 = 116775 14618 ...read more.


Also, since this data was shared within the group, the counting of the population by different members may have created the chance of a differing bias, thus keeping the data inconsistent. The counting of the plant can be difficult due to the way the plant grows in the field, overlapping other dandelion plants. This may also have been the reason to the fluctuations shown in Graph 1, not only due to the excrement and student footsteps in various parts of the field. If this investigation were to be performed again, the steps taken between each successive quadrat should be thoroughly measured with a ruler or tape measure, and then placed, rather than walking 5 steps, which leaves room for huge error. If one wants better representation of data, this is mandatory. When moving towards the fence and away from the base line, one should either look straight ahead and walk in order to stay in the same line transect. Alternatively, the fields could have been marked with lines representing the transects and even the positions of the quadrats, which would have drastically boosted the accuracy and precision of the investigation. Also, if the data is to be shared within the group, then in order to stay consistent, there should be one counter for all the quadrats, removing any discrepancies. These are various ways that the data collection method proves to be very weak and inconsistent. ?? ?? ?? ?? ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Biology essays

  1. Environmental Factors affecting plant growth

    In soil, phosphorus is commonly found in chemical forms that cannot be immediately absorbed by plants, so the farmers have to apply phosphorus to the soil for rapid pant growth. Phosphorus is absorbed by the roots of the plant; which is why root growth stops due to deficiency of phosphorus, mostly in the ionic form of either H2PO4- or HPO42-.

  2. Ecology Open Investigation Does the geographic location affect the biotic and abiotic ...

    The error bar is also shown on the data columns. This graph also shows the units temperature is measured in and the uncertainty. Graph 2.0 - This graph compares the average results of turbidity, oxygen levels, pH levels of Brown Lake of year 2004, 2005 and 2009.

  1. Yeast Population

    just so that we will have the best results we can get. Temperature: The temperature was another factor that was important to this experiment that may have affected the lab data. We cannot have one hot set while the others are in a cold temperature, since it is putting the objective of this experiment in a totally different direction.

  2. Allelopathy. Open Investigation Will increasing the number of allelopathic sunflower plants effect the ...

    In addition to classic yellow, these petals can be orange or maroon in colour, and the seeds may develop in white, black, or striped forms. Rain water collected from the household water tank will be used to water the plants.

  1. Biology Extended Essay 2009

    The amount of sucrose found in fresh oranges varies between 2% to 4%. The other major sugars found include fructose and glucose, which are in a form of monosaccharide molecules. All these types of sugars account for 90% of the total sugars found in orange.

  2. A Local Ecosystem, Patterns in Nature,Life on Earth,The Australian Biota ...

    The second order consumers and so on are carnivores. Food webs are more complex than food chains because they show that predators are not limited to one prey species and they indicate that some organisms are consumed by a variety of predators. In many cases a species may be a preditor to one species and the prey to another.

  1. Carrot growth with differing wavelegnths of light

    Gather all materials. 2. Put 20 cm of dirt (height- wise) in each cup. Measure with the metric ruler. 3. Place 20 cups in each box arranged 4 x 5 (four groups of five). Label each box so that you can remember which plant is which on your excel data table.

  2. Ecosystem Field Walk

    The bee?s scientific name is Apis mellifera. The lady bug?s scientific name is Coccinella magnifica. Keeping in mind that we were in a campus, I felt like there was not a lot of variation or diversity in the plants. There were a lot of trees, mostly eucalyptus.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work