48 CIRCULAR 3 3 3, U.S. DEPARTMENT OF AGRICULTURE 



Kecord should be made of any injurious insects or diseases present, 

 and they should be identified if possible. The recording of second- 

 ary pests is optional: but since they are sometimes destructive or 

 lead to further stand losses in later years, good practice dictates 

 that the presence of all such pests be made a matter of record. 

 Nectria, the locust borer, or Buprestids may be a primary cause of 

 windbreak, mistletoe of stem swellings, etc. 



REPRODUCTION MEASUREMENTS 



Reproduction as considered here includes (1) young treesbelow the 

 minimum size given an individual number on the plot, or, in a stand 

 consisting entirely of young trees, and (2) individuals less than 3.6 

 inches in breast-height diameter. The second classification includes 

 all the tree classes below the pole-wood stage as defined by LefTelman 

 and Hawley (4$, pp. 10-11) in the following: 



1. A sprout is a tree which has grown from a stump over two inches in 

 diameter at the ground line. * * * 



2. A seedling is a tree grown from a seed. * * * 



3. A single seedling sprout is a tree with a single stem which has grown 

 from a stump two inches or less than two inches in diameter at the ground 

 line. * * * 



4. A multiple seedling sprout is a tree with more than one stem, which has 

 grown from a stump two inches or less than two inches in diameter at the 

 ground line. * * * 



5. A root sucker is a sprout from a root. * * * 



Decision as to which of the small trees on a plot are to be measured 

 depends very largely upon the purpose of the study. When trees of 

 appreciable volume are to be dealt with, trees below sapling size often 

 are disregarded unless they occur on subplots. Sometimes, however, 

 study is concentrated on the growth and development of the juvenile 

 stand itself, and sometimes it is desirable to establish in stands of 

 young growth fairly large plots that will be used in later studies. 

 In such cases, particularly if the stands of young growth are dense 

 and are subject to heavy mortality because of suppression, it is often 

 unnecessary to measure each tree, sprout, or sprout clump. Instead 

 it may be desirable merely to run a narrow strip through the plot, 

 mark each tree on this strip with a dab of paint, and record the num- 

 ber of such trees. If the stand is not too dense, a wider strip may be 

 run or trees may be recorded on small subplots. The trees may be 

 recorded by height class alone until the stand has changed sufficiently 

 to warrant more detailed measurements, sufficient data being taken 

 to define clearly the height-age curve. Such a method should be used 

 only with full realization of how the data will be analyzed later. 



For reproduction stands averaging more than 3 feet in height, if 

 growth and development of the stand is the major subject of investi- 

 gation a simple record of the total number of stems, by height classes, 

 per unit of area is usually adequate. In such cases it is sufficient to 

 record this information for a random strip that samples the stand, 

 without establishing a plot for remeasurement. If a plot is needed 

 the boundary should be liberally marked by painting trees inside the 

 plot only. The boundary of the plot and of its divisions can be 

 marked temporarily with string. 



Studies in which young stands are treated require plots and a 

 record of development, The data recorded for some plots ma} T cover 



