Question

(b) The following data was obtained from a study of an ecosystem in which 10 different species were randomly identified and their heights measured. As a Research Assistant for Plant Ecology Laboratory, determine:

(i) Mean height of all species combined

(ii) Variance as a measure of variability in plant height

(iii) Standard deviation

SPECIES HEIGHT(cm)

1. Beech (Fagus spp.) 300 cm

2.Hackberry (Celtis occidentalis) 90cm

3. Southern red oak (Quercus faclcata) 80 cm

4. Dogwood (Comus florid) 600 cm

5. Longleaf Pine (Pinus palustris) 2,450

6. Magnolia (Magnolia sp.) 1,250

7. Red Maple (Hacer rurua) 710

8. Shortleaf Pine (Pinus echinata) 1,350

9. Sweetgum (Liquidamba styracilua) 1,210

10. Wax Myrtle 1,150

11. Cabbage palmetto (Sabal palmetto) 60

12. Live oak (Quercus rubra) 2,055

13. Water oak (Q. nigra) 1,925

14. Scarlet oak (Q. coccinea) 1,075

15. Bald cypress (Taxodium distichum) 996

16. Black hickory (Carya sp.) 878

17. Black oak (Q. macrocarpa) 1,225

18. Wild Blackberry (Prunus serotina) 1,027

19. Eastern Cottonwood (Populus deltoides) 800

20. Virginia pine (Pinus virginiana) 1,330

c) Given the data as indicated above,

(i) Is this a predominantly terrestrial or aquatic ecosystem? Why?

(ii) Would you consider this a mixed hardwood/pine ecosysyetm?

(iii) Which plant species form the overstory of this ecosystem?

(iv) Is this a stable community?

Answer 1

Answer:

Based on the given data:

Sno.	Species	Height (cm)
1	1. Beech (Fagus spp.)	300
2	2.Hackberry (Celtis occidentalis)	90
3	3. Southern red oak (Quercus faclcata)	80
4	4. Dogwood (Comus florid)	600
5	5. Longleaf Pine (Pinus palustris)	2450
6	6. Magnolia (Magnolia sp.)	1250
7	7. Red Maple (Hacer rurua)	710
8	8. Shortleaf Pine (Pinus echinata)	1350
9	9. Sweetgum (Liquidamba styracilua)	1210
10	10. Wax Myrtle	1150
11	11. Cabbage palmetto (Sabal palmetto)	60
12	12. Live oak (Quercus rubra)	2055
13	13. Water oak (Q. nigra)	1925
14	14. Scarlet oak (Q. coccinea)	1075
15	15. Bald cypress (Taxodium distichum)	996
16	16. Black hickory (Carya sp.)	878
17	17. Black oak (Q. macrocarpa)	1225
18	18. Wild Blackberry (Prunus serotina)	1027
19	19. Eastern Cottonwood (Populus deltoides)	800
20	20. Virginia pine (Pinus virginiana)	1330

Descriptive statistics:

Total number of trees of all plant species = 20

Mean height of all plant species can be calculated using the formula:

Variance of the sample can be calculated using the formula:

Standard deviation of the sample can be calculated using the formula:

c) Given the data as indicated above,

(i) Is this a predominantly terrestrial or aquatic ecosystem? Why?

• This is a predominantly terrestrial ecosystem since most of the plant species (including all oak tree, pine tree species) are terrestrial.

(ii) Would you consider this a mixed hardwood/pine ecosysyetm?

• Yes this is a mixed hardwood/pine ecosystem. Hardwoods come from broad-leaved, deciduous trees like oak, beech whereas Softwoods come from coniferous trees such as cedar, fir, and pine. This ecosystem consists of signficant proportion of pine and oak plant species.

(iii) Which plant species form the overstory of this ecosystem?

• Overstory is the highest layer of vegetation in a forest (usually forming the canopy). Long leaf pine forms the overstory of this ecosystem.

(iv) Is this a stable community?

Longleaf pine is one of the most endangered ecosystems in North America and is not a stable community.