LfQLLl "i: NOKIII CAK..I.I.VA l-IXB. 57 



amount <>f hjgVOMOpifl water held l>y heavy day- which is not available 

 for plant growth. 



Old Field . S 7n<. /.v. 'I'lic old field -tand- -andy uplands ami on 



rlay uplands, particularly those on the Piedmont red clays (Cecil soil 

 :.<-n young fall tor the mo-t part into (Duality I or Qualit\ II. 

 hut their rate of growth declines rapidly after a fe\v decade-, some- 

 times l.efore the end of the second decade, and they eventually fall 

 into Quality III. The chief c;m-e for thi< i- that the demands 

 of the stand upon soil moisture soon reach the limits of available 

 supply. Moreover, "ii the upland days the top soil in the old cul- 

 tivated fields is at first loose, permitting the roots freely to pem-- 



:t, and lias a high moisture earn, in.ir capacity. In a - thi- 



soil I nore compact and its water carrying capacity decline-. 



This checks the growth of the lateral routs and as the taproot de- 



i- into the unbroken layer which ha- never been disturbod by the 

 plow, tlie rate of growth of the tree decl 



PKTKICMI.N \ l.\ ol ^\ AI.ITV SITES. 



The rate of height growth or the height of dominant trees at a given 

 fully stocked Croups is the most ready method of ascertaining 

 the quality site when there is growing timber (Table 13). It is de- 

 sirable in the case of middle-aged or old stands to correlate height with 

 volume and basal area per acre (Tahie 35), relative height, relation of 

 diameter to total height (Table 15). In the case of young stands espe- 

 cially on dry upland sites all of these are unreliable factors for predict- 

 ing the capacity of the soil to sustain old stands and they should be sup- 

 plemented by ascertaining the texture of the soil and depth of 

 table. The original forest type where indications of it remain should 

 !> examined to determine the undcrshruhs aM d to compare with Table 1. 

 Abundance of particular undershrubs is a general guide to this extent : 

 a rank growth of gallberry (Ilex glabra) indicates a site highly favor- 

 aide for the rapid growth of the pine; wire grass ( Arittitla stricfa') and 

 low bush black huckleberry (Varclninm ti'iit'lhim) indicates sites which 

 are becoming too dry; sphagnam mosses and BB fetter hu-h 



(Andromeda or Pieris nitida) sites which are becoming too wet. Tile- 

 approximate relation of the height of the water table in different kinds 

 of soil to the quality site for loblolly pine is shown in Figure 3 which 

 the results of a preliminary study of these important problems. 

 The impossibility of depending solely upon height at younger ages for 

 interpreting quality site is illustrated in the stand which is presented in 

 Tables 14, 18 and 20, column 4. The rapid diameter ami height growth 

 of this stand during the early decades i- followed during the fifth 

 decade by an abrupt decline which is reflected by an equally abrupt cul- 

 mination in the volume of the stand. On the other hand, the growth of 

 the trees in column 1 in the same tables show- a slower but su-' 

 rate of height growth, while the declin- does not begin until a much later 

 period. 



