. Elements of ecology. Ecology. 182 Temperature that the speed of development will be increased if either the tempera- ture or the humidity is raised. In this instance more than one limit- ing influence is present. In certain situations, two (or more) in- dependent factors may be unfavorable and botli of these must be im- proved before the organism can continue its growth or extend its range. In other situations, the limiting effect of one factor depends upon the value of another, as in the development of the boll weevil. The two factors acting together produce the limitation, and may be refer
. Elements of ecology. Ecology. 182 Temperature that the speed of development will be increased if either the tempera- ture or the humidity is raised. In this instance more than one limit- ing influence is present. In certain situations, two (or more) in- dependent factors may be unfavorable and botli of these must be im- proved before the organism can continue its growth or extend its range. In other situations, the limiting effect of one factor depends upon the value of another, as in the development of the boll weevil. The two factors acting together produce the limitation, and may be referred to as a "limiting ; The ecologist should always be on the lookout for possible multiple adverse or modifying in- fluences in the environment. Limiting combinations are probably in operation under natural conditions more frequently than is now real- ized (Shelf ord, 1951).. + 10 -10- 1-Absolutely fatal Dormancy or death Dormancy No development 21 days 18 days 16 days 12 days 11 days Absolutely fatal 0 10 20 30 40 50 60 70 80 90 100 Mean relative humidity, % Fig. Generalized scheme indicating the interaction of temperature and humidity in controlling dormancy and the number of days required for develop- ment in the cotton boll weevil. (By permission from Animal Ecology by Chap- man, 1931, McGraw-Hill Book Co.) An illustration of the combined action of temperature and moisture on vegetation is the effect of these factors on the form of growth of plants and on the life form of the whole plant. The climate exerts a major control over the type of plant that can exist in each region, and consequently the life form of the vegetation is to a certain extent an. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Clarke, George L. (George Leonard), 1905-. New York, Wiley
Size: 1339px × 1865px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookpublishernewyorkwiley, booksubjectecology
