DYNAMIC STUDIES OF VEGETATION 39 



the dynamics of natural herbaceous vegetation that has come 

 to the writer's notice is by Dr. David Griffiths in Bulletin 4 of 

 the United States Bureau of Plant Industry (1901), on Range 

 improvement in Arizona, in which he published some measure- 

 ments of the yield of Plantago fastigiaia near Tucson. In Bulletin 

 67 of the same series, by the same author (1904), the investiga- 

 tions were extended to a variety of herbaceous vegetation on the 

 Santa Rita Range Reserve, south of Tucson; and Bulletin 367 

 of the United States Department of Agriculture, by E. O. 

 Wooton (1916), contains additional data from the same area. 

 In 1909 Dr. H. L. Shantz measured the yield of two or three 

 types of grassland in eastern Colorado,' and a little later Dr. 

 A. B. Stout studied a wild hay meadow or grassy peat bog near 

 Madison, Wisconsin, in a similar manner.* A recent European 

 study along this line is by Miss Marietta Pallis in an examina- 

 tion of the marsh vegetation in the delta of the Danube.^ 



Herbs which do not have evergreen leaves obviously renew 

 all their aerial parts and some of their subterranean parts every 

 year. Consequently if one cuts a measured area of prairie or 

 marsh vegetation at the surface of the ground at the end of the 

 growing season he will have the results of a year's activity, 

 minus some of the roots, and whatever foliage may have fallen 

 and decayed during the summer. The loss from decay of spring 

 annuals, early deciduous leaves, etc., can be largely avoided by 

 making tw^o or more cuttings from the same spot a few weeks 

 apart. In marshes, however, there seems to be little loss of 

 that kind, and a single cutting late in the season ought to give 

 pretty accurate results. 



The vegetation can be weighed both at the time of cutting and 

 after it is thoroughly dry, and then burned to determine the 

 amount of mineral matter taken from the soil in a year. An 

 analysis of the ash should throw some interesting light on 

 the composition of the soil and the availability of its several 

 constituents. 



3 Bull. U. S. Bur. Plant Industry, 201: 81. March, 1911. 



* Trans. Wis. Acad. Sci., 17: 405-469, pi. 18-23. October 1912. 



5 Jour. Linn. Soc. (Bot.), 43: 233-290, vl- 1^-25. July, 1916. 



