SAMPLE PLOTS IN SILVICULTUBAL KESEARCH 29 



soft pliable wire. The wire should be attached to the stem loosely, 

 so as to provide for future growth. The branch or twig selected 

 for tagging should be one that is not likely to die soon. 



Tags used in marking reproduction should be attached as system- 

 atically as tags used on older trees. A definite height should be 

 chosen within 6 inches of which the tag will be hung if possible. If 

 the reproduction to be tagged is mostly less than 4.5 feet tall and has 

 an average height of about 18 inches, the tags can be hung about 

 10 to 12 inches from the ground. 



To facilitate quick relocation the tags should generally be hung 

 on the south side, where they will catch the most light. On slopes 

 they should be placed on the side most convenient for examination. 

 Pins used without tags to mark very small seedlings should in each 

 case be set on the same side of the seedling and at about the same 

 distance from it. 



In many cases, the necessity of tagging reproduction can be 

 obviated by locating each individual on a map with reference to 

 some definite point such as a quadrat corner. (This method of 

 locating stems is described on page 52.) 



Pins made of 10-gage telephone wire hold paint fairly well for 

 2 or 3 years. Enamel lasts longer and holds its color better. 



Field notes should in every case be specific as to the height at 

 which tags are attached to reproduction, the position of pins with 

 reference to the seedlings they mark, and the color of the pins used 

 for a given year. 



PLOTS IN PLANTATIONS 



Studies of the development of planted stands differ in purpose 

 from studies of natural reproduction. Although like the latter they 

 aim at determinations regarding survival and growth, they are 

 largely concerned also with source of seed, size or age and condition 

 of planting stock, method and season of planting, and suitability of 

 species for given sites and localities. These latter considerations 

 necessitate sample-plot methods different from those used in studies 

 of growth and mortality alone. 



In planting research the investigator has far greater control over 

 the factors entering into a study than he has in research on natural 

 stands. Sample-plot work dealing with natural stands is subject 

 to restrictions due to the fact that such stands originate and develop 

 principally by chance. In a study of the effect of thinning on 

 second-growth stands, for example, plot location is governed by the 

 location of available second-growth stands of the required species 

 and age, with little opportunity for choice among areas on the basis 

 of soil conditions, site, topography, altitude, or species intermixture. 

 In a planting experiment, on the other hand, the investigator can 

 establish his plots under conditions of site, topography, etc., selected 

 almost at will. 



Plots to be used in studying artificial regeneration must be so 

 located that conditions affecting the test plantation will be closely 

 comparable to those of the area or areas on which it is proposed to 

 apply the results of the study. The area selected for the plots should 

 be sufficiently large to permit installation of a complete series of 

 tests, including replications in time. It should be readily accessible 



