(1) Certain algae and some desert plants 
are able to endure a temperature of 
70 degrees C. Some algae 80-89 
degrees. 
(2) Dry seeds and spores are able to resist 
a high temperature, which would 
kil: some seeds. 
d. Cardinal temperature points for different plant 
functions. 
Acclimatization. 
e. Protection from cold. weather. 
(1) * Halling of leaves: 
(2) Rosette habit of perennials. 
(3) Low stature of arctic plants. | 
5. Wind. Both injurious and beneficial. 
(1) Stunt and deform trees and shrubs. 
(2) pb i yanieeibech. aa | 
(3)  Poljination assisted. 
6. Ground covers. 
a. Snow cover. 
Gr ie @hecks radiation of inear 
(2) Sometimes deforms trees and shrubs. 
(3) Hinders alternate thawing and freez- 
ing in temperate regions, thus pro- 
tecting the roots. 
(4) Conserves moisture. 
(5) Glaciers destroy vegetation, but assist 
in soil formation. 
b. Leaves and other plant remains. 
(1) Protect irom~-cold: 
(2) essen radiation: 
(3)- Conserve moisture, etc. 
c. Living plant covers, protection of shade plants 
in forests. 
(1) From excessive heat and light. 
(2) >" Barona cold 
(3) Air more humid, moisture conserved, 
‘ CEC. 
7. Chemical conditions of the ground or water. 
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