LIFE HISTORY OF SHORTLEAF PINE. 19 
shortleaf pine into the oak and hickory type is particularly notice- 
able. Fresh openings become fully stocked usually during the 
first four years; and, normally, in the mixed pine-and-hardwood 
type, groups of pure young pine of a few prevailing age classes are 
numerous. 
SEED. 
The seed of shortleaf is very small, varying usually from 50,000 to 
70,000 to the pound. The cones which produce them are among 
the smallest for all pines — from 1J to 2J inches in length. They 
persist on the trees for periods of about four years on vigorous shoots 
to seven or eight years on suppressed portions of the crown. Ripen- 
ing in early autumn, the seeds fall by the middle of November and 
lie dormant during the winter. Germination usually takes place 
during March or April. In ordinary seed years the seed averages 
50 to 60 per cent germination, varying quite widely below this stand- 
ard in unfavorable seasons and with unhealthy or old-aged trees. 
One tree 280 years old had a full crop of cones bearing apparently 
good seed. The germinative power of shortleaf pine is retained to 
a large degree for several years. Seed of the 1911 seed crop, kept at 
ordinary living temperatures, gave 56.8 per cent germination in the 
spring of 1914. The seedlings, however, were apparently somewhat 
lower in vigor than those grown from fresh seed. 
The seed of the shortleaf has some advantages over seeds of other 
species. A marked ability to germinate successfully in grass and 
leaf litter, as compared with other southern pines, has been ob- 
served. 1 This is in line with the inherent capacity of the species to 
thrive on the lighter upland soils deficient in soil moisture. The 
very small size of the seed gives it an advantage over larger seed 
in quickly reaching mineral soil. By means of a relatively large 
wing the seed is readily borne by the wind. A breeze will carry 
seed a distance of from 2 to 5 times the height of the tree; and strong 
winds will carry it from one-eighth to one-fourth of a mile. 
Seed is produced both abundantly and regularly. Full crops 
occur at an average interval of about three years, with intermediate 
or partial crops almost every season. In a typical region of the 
Arkansas National Forest, during a period of 13 years commencing 
in 1901, shortleaf pine bore four full seed crops, seven partial crops, 
and failed entirely during two seasons. 2 The years of abundant 
seed were 1902, 1907, 1910, and 1913; 1903 and 1909 were blank 
years, and the others intermediate. Thrifty trees with good light 
supply begin to produce seed at about 20 years. Exceptional trees 
have been noted with cones at 16 years. In open or mixed forest 
i Proceedings of the Society of American Foresters, Vol. V, No. 1, "Loblolly and Shortleaf Pines," by 
W. \Y. Ashe. 
2 Record of seed crops determined by study of crowns in a large logging area, Womble, Ark. 
