Biology Student Experiment copy copy copy PDF

Preview

Summary

I lied i just wanted more access...

Description

Biology Research Investigation 2021 - IA2 Eddie Wicks BIO121H Ms Choy

Rationale: Peramelas Nasuta, a species of Australian bandicoot known as the ‘long nosed bandicoot’, are found in a wide variety of habitats and ecosystems including open, scrub bush, forest, Heath, swamp and urban settings all along the east coast of Australia (Chambers and Dickman 2002). They dig for resources such as fungi and subterranean invertebrates that are varyingly distributed down in the soil beneath them. Peramelas nasuta have a large range and great adaptability of habitats, alongside an omnivorous diet, thus being considered a species of least concern in terms of extinction (Lunney, et al., 2012). The hydrologic cycle, the continuous circulation of water through the environment is a flow-through system that water undergoes in all ecosystems, from evaporation to transpiration and even evapotranspiration (Freedman B, 2021), processes that all contribute to biodiversity of ecosystems through different levels of soil moisture (A. H. Blackwell & E. Manar, 2016). Soil moisture is the water stored in the soil and is affected by precipitation, temperature, soil characteristics and more. Soil moisture is just one of the many abiotic factors that could have an effect on the biodiversity of an ecosystem, and will be investigated in this study. The soil moisture probe used in the experiment detects the soil volumetric water content, and shows a reading between 1 and 10, with a lower soil moisture reading (between 1-2) being concluded to be ‘dry’, and soil with a higher moisture (between 8-10) have been concluded to be ‘wet’. In between these two ranges, the range of ‘moist’ is indicated by the probe as anywhere between 4 and 7. In this study, we worked in the QUT Samford Ecological Research Facility (SERF), a peri-urban ecosystem full of wildlife and vegetation, and home to the Peramelas Nasuta, and carried out observations and experimentation, to investigate whether soil moisture levels affect the abundance of Peramelas Nasuta diggings in a 50 hectare dry sclerophyll forest at SERF. Dry Sclerophyll forests are a common biome in which peramelas nasuta (long-nosed bandicoot) can be found. The theoretical relationship between soil moisture levels, alongside other abiotic factors collected during the field study at SERF including; soil and air temperature, soil ph, and leaf litter and debris depth, will be indicative of where peramelas nasuta diggings are more ideal in a dry sclerophyll forest. By exploring and investigating the patterns and dispersion of these diggings, the intrinsic ecological traits of this species can be analysed and biodiversity can be analysed. Consequently, this consideration led to the question: does soil moisture levels increase the frequency of Peramelas Nasuta diggings in a dry sclerophyll forest?

1

Research question Does increased soil moisture levels increase the abundance of Peramelas nasuta diggings in a 50 hectare undisturbed dry sclerophyll forest in Samford, Queensland? Original experiment The methodology used has been adapted from: - Crome, E., Boswell, E., Johnson, L. (2019). Influence of habitat and distribution on Bandicoot foraging activity. QUT Second Year University Practical (pp. 13-14) - Borger, P., Wright J., Munro, L., Grant, K. (2018). Analysing vegetation patterns using a transect line. Nelson Qscience Biology: Units 3 & 4 (pp. 23-24) The original experiment conducted ran a 100 metre transect line throughout a dry sclerophyll forest to determine and measure the presence and locations of bandicoot diggings. However, this experiment was slightly modified in order to increase sample size and accuracy in the findings, by increasing the amount of quadrats placed.

Modification to Methodology To ensure that sufficient, relevant data was collected, the following modifications to the methodology have been refined and extended to increase the number of samples and measurements of data collection locations, as the original experiment had a very limited sample size. Refined by: •

•

•

Not measuring or recording soil surface temperature or light intensity but focusing on one abiotic factor (soil moisture), to increase the efficiency of the experiment and decrease the number of uncontrolled variables which could influence any relationship found between the abiotic factor and number of bandicoot diggings. In the original experiment, data was collected every 20 meters, however in order to obtain more accurate results, quadrats were placed 10 meters apart therefore data was collected at shorter intervals. This allows for more accurate data and minimises error. In the original experiment, the size of the quadrats used along the transects had a 5mx5m perimeter, however in this experiment 1mx1m quadrats were used to replace them, allowing for less variables disrupting data, thus leading to less room for error in the findings.

Extended by: •

Increasing the number of transect lines from 1 to 5, in order to improve accuracy of the trends found within the mean calculations made.

2

Safety and Ethical Considerations Hazard UV Radiation

Risk As we are exposed to UV radiation there is a risk of becoming sunburnt There is a risk of bites, infections of diseases

Wildlife

Damaging Ecosystem

Interference with the function of the biological ecosystem

Management Sunscreen, wide brim hat, and long sleeve clothing to be worn Wear long clothing, enclosed shoes and have first aid available Follow transect line closing and do not deliberately break branches or any habitats

Raw and Processed Data Table 1: Sample Calculations The mean was calculated in excel by using the AVERAGE function Mean M = 0.18

Standard Deviation

Standard Deviation was calculated in excel by using STDEV function and the accumulation of all data from the chosen quadrat.

1.74 Standard error

√40

= 0.27

3

Table 2: Processed and Raw Data

Interpretation: The raw data about has been processed to form later analysed evidence. The data addresses any anomaly’s and the effects of soil moisture levels on bandicoots diggings (addressing the research question). *Highlighted data = anomaly’s removed

AVG Bandicoot Diggings

Soil Moisture Range 1 to 2

1 1 0 0 0 0 0 0 0 0 0

0.181818182

3 to 4

2 3 2 3 4 2 4 4 2 3 4

2

5 to 7

2 2 1 3 2 1 1 1 0 1 0

0

2.916666 667 1 0 1 1

1.06 25

4

Average Number of Bandicoot Diggings

Average Number of Bandicoot Diggings vs Soil Moisture 4

3.5 3 2.5 2 1.5 1 0.5 0 -0.5

1 to 2

-1

3 to 4

5 to 7

Soil Moisture Range Average Number of Bandicoot Diggings

Figure 1: Mean Soil moisture levels (collected with soil moisture probe) and mean number of Peramelas Nasuta Diggings Interpretation: The literature shows that the ideal soil moisture level for the Peramelas Nasuta to forage and dig in a dry sclerophyll forest is between 3 to 4. This relationship is reflected in Figure 1, indicting that the correlation between the biotic and abiotic factors were what was expected for the experiment. The data displays that drier soil has the most negative effect on the number of bandicoot diggings, although if the soil level is too moist there is also quite a negative effect in the number of bandicoot diggings. However, the most positive effect on the number of bandicoot diggings is when the soil moisture is within the ideal range identified of 3 to 4. Further testing would need to be conducted to confirm this relationship as there is a statistically significant overlap in error bars between the lower and higher soil moisture ranges. Analysis: The standard deviation error bars are showing that the only conclusion that can be conclusively made is that the number of bandicoot diggings was the highest if the soil moisture was between 3 or 4 with an average number of diggings just under 3. As the error bars do not overlap with any different ranges of the independent variable thus most of the data is significantly different. Although, for the 1 to 2 range and 5 to 7 ranges have a statistically significant overlap between the error bars and thus the data may be said to not be that difficult between the ranges. As a result it cannot be completely determined whether having drier or more moist soil has the most detrimental impact on the number of bandicoot diggings. Therefore, we can conclude that if the soil moisture is outside the optimal range that either way it would negatively impact bandicoot foraging.

Evaluation Limitations of the Evidence Uncertainties and limitations could include the mean calculations observed in the analysis of the evidence. As the mean was calculated from a small sample size which may not be indicative of the whole population we cannot be

5

As the data was also collected throughout different times of the day, the moisture could have be removed from the soil as the intensity and amount of the light on the soil increases. The soil moisture calculation process may also hinder the reliability of the data as the moisture probe was not calibrated and causes imprecision and inaccuracies as a result the relationship found may have more error and could ultimately have overlap in the error bars and thus ruin the relationship determined. Sources of Error Effecting Reliability •

•

Measurements of temperature in soil and above soil could be affected due to parallax error. This effects the precision of measurements and overall results, as a displacement in the apparent position of an object viewed along two different lines of sight can cause an illusion of a lower than true reading of soil temperature and leaf litter and debris depth due to the downward inclination when reading and recording measurements. The sample size may not account for the whole ecosystem, as less data was collected and it may make it more difficult to determine an outliers, as one was only found

Effecting Validity •

Measurements for the soil moisture were only taken once per quadrant and the ph and soil moisture probe was not calibrated which reduces the reliability of the instrument and imprecisions could be consistent in the experiment due to systematic errors

Suggested Improvements and Extensions Suggested Improvements In this experiment, the reliability of the data could be improved by; • •

Increasing testing – Increases the sample size and chance that the data and relationship found is reflected by the whole population and ecosystem Calibration – Calibrating the instruments (ph and moisture probe) will keep the data the instruments collects accurate and reliable as well as consistency

Suggested Extensions • •

Redirect the experiment by focussing the investigation to only the abiotic and biotic factors rather than unnecessary factors, thus improves the precision of the experiment Extend the experiment by increasing the number of times it was done throughout the year to make sure the seasons don’t impact the relationship.

Conclusion In conclusion, when the soil moisture is within the ideal range of 3 to 4 the number of bandicoot diggings is positively effected and increases. Although, if the moisture is too low it had severely impacted the number of diggings observed, this is also the case if the moisture levels recorded were too high and thus it could not be determined whether having drier or more moist soils had the most negative impact on bandicoot foraging. A conclusive relationship was found between the moisture

6

levels of the soil being in the optimal range and an increase in the number of bandicoot diggings, however, limitations did exist that could possibly limit the reliability and validity of this relationship. Although, further studies would still need to conducted to improve the accuracy and precision of the experimental process.

Reference List Bandicoots. (2021). In K. H. Nemeh & J. L. Longe (Eds.), The Gale Encyclopedia of Science (6th ed., Vol. 1, pp. 483-484). Gale. https://link.gale.com/apps/doc/CX8124400264/SCIC?u=uq_bshs&sid=SCIC&xid=417be048

7

Freedman, B. (2021). Water Cycle (Hydrologic Cycle). In K. H. Nemeh & J. L. Longe (Eds.), The Gale Encyclopedia of Science (6th ed., Vol. 8, pp. 4739-4741). Gale. https://link.gale.com/apps/doc/CX8124402608/SCIC?u=uq_bshs&sid=SCIC&xid=c1a9785e Garkaklis, M. J., Bradley, J. S., & Wooller, R. D. (2003). The relationship between animal foraging and nutrient patchiness in south-west Australian woodland soils. Australian Journal of Soil Research, 41(4), 665+. https://link.gale.com/apps/doc/A106647611/SCIC?u=uq_bshs&sid=SCIC&xid=77c541d2 Habitat. (2021). In K. H. Nemeh & J. L. Longe (Eds.), The Gale Encyclopedia of Science (6th ed., Vol. 4, p. 2101). Gale. https://link.gale.com/apps/doc/CX8124401177/SCIC?u=uq_bshs&sid=SCIC&xid=cbd93129 Lunney, D., Dickman, C. & Menkhorst, P. 2016. Perameles nasuta (errata version published in 2017). The IUCN Red List of Threatened Species 2016: Retrieved 16 April 2021 from e.T40554A115173969. https://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T40554A21966169.en. The water cycle [Drawing]. (2016). A. H. Blackwell & E. Manar (Eds.), UXL Encyclopedia of Weather and Natural Disasters (2nd ed., Vol. 5). UXL. https://link.gale.com/apps/doc/PC3629587253/SCIC?u=uq_bshs&sid=SCIC&xid=b518c49a

8...