1 / 10

Biodiversity

Biodiversity. Average Size. Measure all trees in a transect or quadrat. Produce a size-frequency histogram to show the size distribution. Can also calculate the average size tree. Quadrat Sampling. Randomly select plots and count all individuals in that plot. Each quadrat = 200m 2 .

accalia
Télécharger la présentation

Biodiversity

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Biodiversity

  2. Average Size • Measure all trees in a transect or quadrat. • Produce a size-frequency histogram to show the size distribution. • Can also calculate the average size tree.

  3. Quadrat Sampling • Randomly select plots and count all individuals in that plot. • Each quadrat = 200m2. • Can calculate density as #/m2 then multiply by total area to estimate the total # of trees. • 60,703 m2 = 15 acres

  4. Transect Sample • Randomly select a transect of known area and count every tree in that transect. • Each transect = 90m2. • Can calculate density for each tree species. • 60,703 m2 = 15 acres

  5. Measuring Biodiversity • The simplest measure of biodiversity is the number of species – called species richness. • Usually only count resident species, and not accidental or temporary immigrants • Another concept of species diversity is heterogeneity: Heterogeneity is higher in a community where there are more species and when the species are more equally abundant.

  6. Diversity Indices • A mathematical measure of species diversity in a community. • Reveals important information regarding rarity and commonness of species in a community.

  7. H= - pi(lnpi)  Larger H = more diversity Shannon-Wiener Diversity Index (H) • Variables associated with the Shannon-Weiner Diversity index: • S – total number of species in the community (richness) • pi – proportion of S made up of the ith species • Hmax = ln(S) • EH – equitability (evenness; b/t 0 and 1) = H / Hmax

  8. Species richness and equitability affect the Shannon Wiener index.

  9. D= 1 - pi2ranges from 0 to 1 Simpson’s Index • N = total number of individuals • pi = proportion of each species • Simpson’s Index of Diversity = 1 – D • Ranges from 0 to 1  Low to high diversity

  10. Species richness and equitability affect Simpson’s index.

More Related