710 AMERICAN FORESTRY 



The work of the Forest Service in the past has been largely of an exten- 

 sive nature along constructive lines, but now the work has become more 

 settled so that in the past few years it has been much more intensive. The 

 sample plots which have been maintained and studied carefully have taken 

 considerable time, due to the great care which is exercised in this kind of 

 work, but the i*esults obtained are something that can be depended upon 

 since the factor of careless work is entirely eliminated. An illustration of 

 some of this intensive work done on the San Isabel National Forest might 

 explain some of the whys and wherefores. It has always been the idea of 

 nursery men throughout the country that the best depth of sowing seed was 

 to sow it two to three times the diameter of the seed. This was done as nearly 

 as possible in all the seed sowing, but when no appreciable results were 

 obtained, apparently due to the fact that the seed dried out before germina- 

 tion took place, the question naturally arose whether or not the seed was 

 planted deep enough to overcome the drying effect of the dessicating winds 

 which are prevalent in the Rocky Mountain Region during different seasons 

 of the year. Small typical areas, called sample plots, were marked out by 

 having white posts with black tops driven in at the corners of the plot to 

 designate the boundaries. The size of the plots was but 40' x 40' in order 

 that the work be as intensive as possible. Five white stakes with red tops 

 were placed at five different points in the samj>le plot to mark the sampling 

 points, that is, the points where to take the soil samples which are used in 

 determining the amount of moisture in the soil. The seed is carefully tested 

 in order that the kind of seed may not have any unknown influence upon the 

 results. The same amount of seed was sown in each sample plot, the only 

 difference being that they were sown at different depths. The seed in one bed 

 was shown at a depth of Yi" in another bed 1/2" and so on up to 2" in depth. 

 Soil samples to determine the amount of moisture in the soil were taken at 

 different seasons of the year so as to know what influence this had upon the 

 final results. ^ATienever any of the seed germinated a small white peg bearing 

 the date of observation was placed alongside of the seedling as a permanent 

 record. In some cases where the work is most intensive and all the factors 

 of influence are measured, anemometers (wind guages) are used to measure 

 the velocity of the wind, psychrometers to determine the amount of moisture 

 in the atmosphere and photometers to determine the intensity of the sunlight. 

 In this way all the factors concerned are measured on the diffeent plots 

 so that the results obtained on the different areas can be explained by facts 

 and figures and not by guess work. After repeated observations it was found 

 that the seed should be sown from one to one and one-half inches in depth 

 in order to produce the best results, because these depths showed 25 to 50 

 per cent better germination than the other depths, under exactly the same 

 conditions. While these results are not conclusive they offer at least a 

 criterion on which the Forest Service men can base their work on a larger 

 scale. This class of work is slow, it will, however, ultimately mean that the 

 Forest Service work will be built upon such a sound basis after years of 

 experimentation that the saying, "success comes to him that tries," will not 

 be amiss. 



