Biodiversity Study Notes

  • Objectives

    • Knowledge
    • Define Biodiversity: Variation among living organisms, observable through phylogenetic trees.
    • Distinguish between species richness and diversity indices (Shannon Diversity Index) to estimate biodiversity.
    • Skills
    • Experimental Design:
      • Design a study to quantify biodiversity at different disturbance levels in the arboretum.
      • Identify key study elements: Independent variable, dependent variable, control, treatment, and type of study (Descriptive, Non-experimental, Experimental).
    • Data Collection and Analysis:
      • Sampling techniques
      • Quantification of biodiversity (species richness and Shannon Diversity Index)

  • Understanding Biodiversity

    • Importance: Provides ecosystem services that benefit humans directly and indirectly (e.g., food sources like bluefin tuna, essential plant products like bread and coffee, and medicines from various species).
    • Example of ecosystem services:
    • Pollination (bats, birds, insects)
    • Soil formation (fungi, bacteria)
    • Water purification (plants, microbes)
    • Economic Value:
    • The control of crop-eating insects by bats is valued at $4 billion/year.
    • Loss of biodiversity can lead to loss of services; e.g., pollination issues in China due to pesticide use lead to humans hand-pollinating crops, increasing costs.
    • Global valuation of ecosystem services (1997 study): $33 trillion, highlighting the interdependence of biodiversity and human well-being.

  • Threats to Biodiversity

    • Current extinction rates are 100 to 1000 times greater than normal rates.
    • Mass extinction event urgency parallels historical events (e.g., the asteroid impact that wiped out dinosaurs).
    • Major threats include:
    • Habitat destruction and degradation:
      • Caused by human activities: logging, damming, plowing, and urban development.
    • Degradation examples include habitat fragmentation, creating isolated edges that can harm native species and favor invasive species.
    • Purpose of study: Test if habitat edges affect biodiversity in the JMU arboretum.

  • Measuring Biodiversity

    • Definitions:
    • Species richness: Total number of different species in a location.
    • Species abundance: Total number of individuals of each species present.
    • Shannon Diversity Index (H’): Considers both species richness and abundance/evenness.
      • Calculation steps:
      • Calculate proportions (pi) of each species.
      • Use the equation:
        H′=−∑<em>i=1n(p</em>iimesln⁡(pi))H' = - \sum<em>{i=1}^{n} (p</em>i imes \ln(p_i))
      • H’ ranges from 0 (no diversity) to over 7 (high diversity).
      • Example results: Site A (H' = 1.61) vs. Site B (H' = 0.78) demonstrate the impact of evenness on diversity assessment.

  • Field Methods

    • Use of plots and transects to standardize area sampled at each site for comparability.
    • Experimental setup activities include:
    • Group brainstorming on hypothesis, study design, sampling measures at edge and interior sites.

  • Sampling Protocols

    • Group responsibilities:
    • Count species and record data.
    • Specifics for each group:
    • Plants: Survey live plants within 1 meter of transect.
    • Fungi: Survey fungi within 1 meter; expand if few are found.
    • Invertebrates: Sweep and collect samples, ensuring consistency in person-minutes surveying.
    • Data recording required for all groups.

  • Lab Report Writing

    • Structure:
    • Inverted pyramid style for introduction, detailing study goal, hypothesis, experiment outline, and background info on biodiversity importance.
    • Include literature citations in APA format, avoiding direct quotes and ensuring original paraphrasing.
    • Acknowledgment of academic integrity and proper citation usage in all derived works.