1. Plant Sampling Techniques

2. Warning!
Lab lectures included on Lecture Exam #1!

3. Sampling: Why? Best answer is 100% sample (count/measure everything)
Not practical
Ex, describe vegetation Lee County AL

4. Accuracy vs. Precision Accuracy: how close samples to
Precision: similarity measurements

5. Accuracy vs. Precision Accuracy: not known unless
Precision: standard error of mean (S)
Standard deviation

6. Sampling Choosing technique depends on: 1) Desire for 2) Objective
3) Time/money
4) Tradition!
“Without our traditions, our lives would be
as shaky as…..a fiddler on the roof!”

7. Importance Often: how “important” a plant species is
3 measures importance (sp. A)
Density of A = No. inds. per unit area (reflects abundance of A)
Frequency of A = No. times sp. A in samples divided by total number samples (reflects pattern of A)
Cover of A = Percent area occupied by A (reflects biomass of A)

8. Focus on Cover Many ways to get cover (biomass) data:
1) harvest & measure biomass
2) visual estimation
Note canopy edges “filled in” by observer

9. Focus on Cover Many ways to get cover (biomass) data:
1) harvest & measure biomass
2) visual estimation
3) point frame

10. Focus on Cover Many ways to get cover (biomass) data:
1) harvest & measure biomass
2) visual estimation
3) point frame
4) moosehorn crown closure estimator

11. Focus on Cover Many ways to get cover (biomass) data:
5) Trees: basal area (area tree trunk per unit area). Bitterlich method.

12. Focus on Cover Many ways to get cover (biomass) data:
6) Trees: DBH (diameter at breast height: 4.5 ft or 1.3 m)

13. Other Challenges
Clonal plants: density (how determine individual?)

14. Other Challenges Clonal plants: density (how determine individual?)
Canopy overlap: where boundaries?
Border calls: in or out?
Solution:

15. Importance Often: how “important” a plant species is
3 measures importance (sp. A)
Density of A = No. inds. per unit area (reflects abundance of A)
Frequency of A = No. times sp. A in samples divided by total number samples (reflects pattern of A)
Cover of A = Percent area occupied by A (reflects biomass of A)

16. Importance Calculate Importance Value (IV)
Sum Relative Density, Relative Frequency, and Relative Cover

17. Importance Calculate Importance Value (IV)
Sum Relative Density, Relative Frequency, and Relative Cover
IV= Rel. density + Rel. frequency + Rel. cover
<300%= < 100% + < 100% + < 100%

18. Sample Techniques 1) Quadrat methods
2 dimensional sample unit used: quadrat
Quadrant?

19. Quadrat Method a) Shape?
Oblong better: picks up more variation per sample
But: less perimeter means less in/out decisions (source error)
Compromise: be reasonable!

20. Quadrat Method
b) Size?
VITAL for determining plant pattern (& important for density measurement)
Can use species-area curve

21. Quadrat Method c) Number? Suggestions include: A) Sample 1-20% of area
B) Include 95% of species
C) Use Running Mean Graph (Quadrat Sampling Lab #4)

22. Belt Transect Method Also 2 dimensional method Useful dense vegetation
Useful sampling along sharp environmental gradient

23. Belt Transect Method
Example diagram and calculation of Importance Value of species A 2m 2m
Environmental gradient 2m 2m
4 species: A = red, B = turquoise, etc.

24. Belt Transect Method Density of A = 10/40m2 = 0.25/m2
Frequency of A = 9/10 = 0.9
% Frequency of A = 0.9 X 100% = 90% 2m 2m
4 species: A =red, B= turquoise, etc.

25. Belt Transect Method
Cover of A: Assume visually estimate covers each species
Values for A:
10%, 15%, 15%, 10%, 0%, 10%, 5%, 5%, 10%, 10%
Mean cover of A= Sum covers/10 = 9% 2m 2m
4 species: A = red, B = turquoise, etc.

26. Belt Transect Method
Do density, frequency, cover calculations for all other species (B, C, D) 2m
4 species: A = red, B = turquoise, etc.

27. Belt Transect Method
Do density, frequency, cover calculations for all other species (B, C, D)
IV= Rel. density + Rel. frequency + Rel. cover
For sp. A:

28. Belt Transect Method
Do density, frequency, cover calculations for all other species (B, C, D)
IV= Rel. density + Rel. frequency + Rel. cover
For sp. A:
Rel. density = density of A/density of all species X 100%
Rel. frequency = frequency of A/frequency of all species X 100%
Rel. cover = cover of A/cover of all species X 100%
Calculate IV for other species (B, C, D)

29. Belt Transect Method
IV calculations lab #1 (plotless sampling) + lab #4 (quadrat sampling)
Quadrat lab
Plotless lab

30. Line Intercept Method 1 dimensional method (line has no width)
Useful dense vegetation: scrub
Scrub in Australia

31. Line Intercept Method
Cover: record distances covered by canopies

32. Line Intercept Method Cover: record distances covered by canopies
Cover frequency: Divide line into units. Determine frequency of species in units

33. Line Intercept Method
Cover: record distances along line covered by canopies of species
Density?