236 



TIMBER RESOURCES FOR AMERICA' S FUTURE 



This basic information was obtained by field 

 examiners from a variety of sources such as an 

 interview with tlie owner, county records of various 

 agencies, interviews with neiglibors, local foresters, 

 and by consulting aerial photographs. These 

 photographs were a major source of information 

 particularly for estimates of the area in each 

 forest type on an ownership. 



With the general location of the recently cut 

 area ascertained, the field examiner made a recon- 

 naissance to determine roughly its area and shape 

 and a route of travel was determined that would 

 represent all conditions. By reference to guides 

 in a regional field manual, the number of one-fifth 

 acre sample plots to be measured in the East or 

 the number of sample points from which measure- 

 ments were taken in the West and the distance 

 between plots or points appropriate for an area 

 of the approximate size to be examined were 

 determined. Each plot or point was then located 

 on the ground, measurements taken, and computa- 

 tions completed to arrive at the percentage of 

 existing stocking, total stocking (existing plus 

 prospective), stocking modified by composition 

 if required, and the latter modified by effect of 

 felling age if required. The last computation 

 resulted in the productivity index. 



Thus in the example shown by figure 79, there 

 were six sample plots which provided six separate 

 ratings of existing stocking. These were aver- 

 aged to get a rating of existing stocking for the 

 tract. Average ratings for each of the other three 

 elements were derived similarly from the appro- 

 priate records for these six plots. All average 

 ratings were recorded on a standard form for the 

 pine type on the particular ownersliip together 

 with identifying information and other observa- 

 tions made on the property to meet objectives of 

 the survey. Had there also been recent cutting 

 in the oak-pine type, a separate examination of 

 this cutover area would also have been made. 

 Data similar to those described for the pine type 

 would have been recorded separately for the oak- 

 pine type. 



Essentially the same system was used througli- 

 out the country. Methods in the East and West 

 varied in that sample plots were used universally 

 in the East but the sample or observation "point" 

 was adopted for western conditions. Both the 

 sample plot and sample point systems are de- 

 scribed in the appendix section Criteria for Rating 

 Productivity. 



How the Survey Results Were 

 Summarized 



The method, in broad outline, of how tlie ratings 

 from this example would become part of final 



results is of interest. Assume that the final 

 average productivity index calculated from the 

 six plots shown in figure 79 was 58. Reference to 

 the classification of indexes shows that this rating 

 would be included in the medium productivity 

 class. Since there were 70 acres of pine type, part 

 of which was cut, and no cutting in the oak-pine 

 type, the operating area of this property was 

 recorded as 70 acres and the productivity level as 

 medium. 



To follow tlie summarizing of this final observa- 

 tion, refer to table 136, page 238. This table shows 

 that for the country as a whole 32 million acres in 

 ownerships of 100 to 500 acres were recorded as 

 operating. The ownership used as an example 

 contributed to this 32 million acres. Note further 

 from table 1 that 36 percent of the operating area 

 in the 100-500 acre ownei'ship class was found to 

 be in the medium class of productivity. This 

 percentage was derived from a tabulation of 

 results showing that there were 11.5 million acres 

 of operating area in the medium class. This area 

 represented 36 percent of the 32 million acre 

 operating area in the 100-500 acre ownership 

 class. The example of figure 79 contributed to 

 the total of 1 1.5 million acres in tlie medium class. 



How High Are the Standards? 



In devising standards around the basic premise 

 that they should reflect conditions attainable 

 under current operating conditions, judgment is 

 necessarily used to interpret the technical forestry 

 information at hand. The varying opinions 

 brought out during the process of applying judg- 

 ment to meet the basic premise are the source of 

 conflicting views on standards. 



Some feel that the standards are too liigh and 

 therefore will emphasize pessimistic aspects. 

 Others have expressed the opinion that standards 

 are too low. A number of considerations could 

 liave been included in the basic premises and 

 procedural concepts that woidd have led to stricter 

 standards. The more important of these are 

 discussed as enumerated below: 



1. Standards could have been built up on the 

 basis of trends toward more intensive forestry. 

 Standards developed on tliis basis would be 

 liigher tlum those adopted. However, it was 

 felt that standards related only to judgments 

 of current and reasonable attainability under 

 average operating conditions would be of 

 more practical value. 



2. Procedures for measin-ing eft'ect of felling age 

 made no specific provision for growth of high- 

 quality sawtimber. For many species, the 

 age of maximum mean annual growth in 

 board-foot volume occurs before appreciable 



