BIOS1301 Method and Results Selena Ung

Site Description

  • Lachlan Swamp in Centennial Park (CP)

    • A recreational area with diverse plant communities:
    • Dry and wet ecosystems.
    • Native vegetation.
    • Freshwater wetland environment minimally impacted by urbanization.
    • Water levels fluctuate due to rainfall and surface runoff, enhancing biodiversity.
    • Important for invertebrates' ecological support.

  • Randwick Environmental Park (REP)

    • Rehabilitation into an ephemeral wetland, experiencing dry and wet phases.
    • Diverse habitats due to a combination of grasslands and ephemeral wetlands.
    • Close to main roads and housing, unlike CP.
    • Supports a variety of bird species, showing ecological restoration successes.
    • Provides pathways and open spaces for human recreation and ecological conservation.

Methodology

  • Leaf Litter Sample Collection:

    • Sample Volume: 50L collected from both sites.
    • Two groups assigned to each park for systematic searches.
    • Process:
    • Portion the litter into separate tubs for monitoring and identification.
    • Capture and identify individual invertebrates; new species labeled alphabetically for classification.
    • Avoid double counting by using petri dishes.
    • Data entered into an Excel sheet for organized analysis.

  • Data Analysis:

    • Aspects analyzed: species richness, relative abundance, and Shannon biodiversity index.
    • Analyzed using R version 4.3.0 in R-Studio, employing the tidyverse library for data handling.
    • Histograms to show prevalence of invertebrates in urban areas.
    • Results presented in means and standard deviations.
    • Comparison box plots created using the patchwork program.
    • Diversity data analyzed using the vegan program.

Results

  • Mean Abundance:

    • CP: 170 individuals (SE = 26.7)
    • REP: 97 individuals (SE = 13.0)
    • Higher variability observed at CP.

  • Species Richness:

    • CP: Mean = 17.8 (SE = 2.1); lower median richness.
    • Smaller interquartile range (IQR).
    • REP: Mean = 23.7 (SE = 2.3); higher median richness indicating greater variability.
    • Higher range than CP by 5.92.

  • Shannon Index (H):

    • CP: Mean = 1.8 (SE = 0.2); lower diversity.
    • REP: Mean = 2.60 (SE = 0.26); greater diversity and even distribution of species.

Figures

  • Figure 1: Site map of CP and REP using Google Earth Pro, illustrating urban and recreational zones with main roads.
  • Figure 2: Distribution of invertebrate counts showcases substantial differences; wider range and higher median at CP.
  • Figure 3: Species richness distribution showing REP's higher richness and variability compared to CP.
  • Figure 4: Boxplot of the Shannon Diversity Index revealing REP's higher diversity levels compared to CP.