ROOTED AQUATIC PLANTS IN LIMNOLOGY 



121 



often specific in their choice of aquatic 

 plants for food and shelter and an under- 

 stand in<»- of the ecology of such plants is 

 of prime importance in order to carry out a 

 natural program of conservation (McAtee 

 1917). 



A word may be said concerning the in- 

 telligent use of lakes by resort owners. It 

 has been shoAvn that lakes are geologic fea- 

 tures that evolve along definite trends. 

 AVith this evolution goes definite floral and 

 faunal development. It seems then that a 

 lake should be studied and made to serve 

 those ends for which it is best suited. A 

 lake with very soft water, for instance, 

 may never be a good fishing lake, since it 

 lacks in food supply, and it would be a 

 waste of elfort to stock it. On the other 

 hand it may become important to a diifer- 

 ent type of aquatic recreation. Lakes with 

 abundant plant life may be undesirable as 

 bathing and boating lakes, but they may 

 become important to the fisherman by intel- 

 ligent husbandry. 



Problems Requiring Investigation 



1. Relation of light, temperature, harel- 

 7iess, etc., to aquettic j)la)it distribution. 

 These environmental studies should be un- 

 dertaken if possible with controlled con- 

 ditions. When general rules are arrived at 

 they should be compared with field results. 



2. Relation of sedimentation to the 

 rooted aqueitic plant. The factors of sedi- 

 mentation and plant succession are closely 

 related as dynamic processes, and in each 

 region, w'here lakes occur, there is need for 

 careful observations. A fuller understand- 

 ing of the sediments, their origin, structure, 

 and eft'ect upon the lake Avaters is needed 

 before a great deal can be accomplished in 

 plant succession. One of the most pertinent 

 problems is a better understanding of the 

 organic sediments. 



3. Histological and Morpliological stud- 

 ies. ]\luch can be accomplished in the field 

 of ecological anatomy and morphology that 

 maj^ explain the distribution and tolerances 

 of aquatic plants. Those species of definite 

 value to fish and game should have further 

 studies made of their reproduction. His- 



tological studies should be made in relation 

 to the physiological experiments. 



4. Critical taxonejniic studies. Studies of 

 this nature are important for every region 

 where hydrophytes occur. There should be 

 close correlation between these studies and 

 ecological observations, for there are not 

 only important taxonomic questions to 

 solve, but the presence of certain species, 

 varieties, and forms of rooted hydrophytes 

 within lakes is often indicative of very spe- 

 cific conditions. Taxonomy will become 

 one of the eeologist's most important tools, 

 if use is made of the terms, species, varie- 

 ties, and forms and there is an understand- 

 ing of the environments in which they 

 occur. 



5. Productivity studies. The pursuit of 

 productivity studies is important because 

 they are closely related to the other fields 

 of limnological investigation both scientific 

 and applied. 



6. Relation of aquatic phnits to animals. 

 Many phases present themselves for inves- 

 tigation when the relations of animal life 

 to plants are considered and only a few can 

 be suggested here : 



a. The parallel succession of animals and 

 plants. 



b. Aquatic plants as food to specific ani- 

 mals. 



c. The dispersal of aquatic plants by 

 animals. 



d. The role of aquatic plants in the 

 mori^hology of the invertebrates. 



e. Population studies of animals in cer- 

 tain plant communities. 



References Cited 



Baker, F. C. 1918. The Productivity of Invertc- 



l)rate Fish Food on the Bottom of Oneida Lake. 



Tech. Pub. No. 9, N. Y. State Coll. Forestry. 

 Brown, W. H. 1911. The Plant Life of ^ Ellis, 



(Treat, Little, and Long Lakes in North Carolina. 



Contrib. U. S. Nat. Herb., 13: 323. 

 Fassett, N. C. 1930. The Plants of Some ISTortli- 



eastern Wisconsin Lakes. Trans. Wis. Acad. Sci., 



25: 157. 

 Frohxe, W. C. 1938. Contribution to Knowledge 



of the Limnological Eole of the Higher Aquatic 



Plants. Papers Mich. Acad. Sci. 

 Gates, F. C. 1926. Plant Succession about Doug- 

 las Lake, Cheboygan County, Michigan. Bot. 



Ga-., 82: 170. 



