Volume 14 Number 12 



The Plant World 



A Magazine of General Botany 

 DE:CBMBKR, 1911 



PAPER ATMOMETERS FOR STUDIES INVj^ 



EVAPORATION AND PLANT x'j^^^^^^^^^^' 



TRANSPIRATION ^M^ f^ K 



Burton Edward Livingston 



The porous-cup atmometer * and its light-absorbing modi- 

 rication f ^vere devised to record the effects of the evaporating 

 power of the air and the intensity of sunshine as these factors 

 might influence the rate of water loss from ordinary leaf\ plants. 

 The instruments, however, fail to simulate the essential struc- 

 ture of plant foliage in respect to the relation existing between 

 the amount of exposed water surface and the volume of con- 

 tained water. While the amount of contained water in leaves 

 is very small, relative to the moist cell walls (internal and ex- 

 ternal) from which evaporation occurs, the volume of water in 

 the poious-cup is very much greater, in proportion to the moist 

 clay surface exposed. It thus comes about that the tempera- 



♦Livingston, B. E. — Operation of the Porous-Cup Atmometer, Plant World, 13: 111-118, 

 1910. The literature of the instrument is there cited. Additional citations bearing upon 

 the instrument and its use are the following: 



Dickie, M. G. — Evaporation in a Bog Habitat, Ohio Naturalist. 10: 17-23, 1909. 

 Dachnowski, A. — Physiologically Arid Habitats and Drouth Resistance in Plants. Bot. 

 Gaz., 49: 325-339, 1910. 



Transeau, E. N. — A vSimple Vaporimeter. Bot. Ga/., 49: 459-460, 1910. 

 Brown, W. H. — Evaporation and Plant Habitats in Jamaica. Plant World, 13: 268-272. 

 1910. 



Livingston, B. E. — A .Study of the Relation Between Summer Evaporation latensity and 

 Centers of Plant Distribution in the United States. Plant W'orld. 14 205-222, 1911. 

 I-ivingston, B. E. and Brown, W. H. — Relation of the Daily March of Transpiration to 

 Variations in the Water Content of Foliage Leaves. Bot. Gaz., in press. 

 Dachnowski, A. — The Vegetation of Cranberr>' Island (Ohio) and its Relations to the sub- 

 stratum. Temperature and Evaporation. Bot. Gaz., 52: 1-33, 1911. 

 Fuller, E. G. — Evaporation and Plant Succession. Bot. Gaz. 52: 193-208, 1911. 



fLivingston, B. E., Light Intensity and Transpiration. Bot. Gaz. 52: 417-438, 1911. 

 Idem — A Radio-Atmometer for Comparing Light Intensities. Plane World, 14: 96-99, 1911 



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