102 SILVICULTURE-METHODS OF NATURAL REPRODUCTION 



2. Seed-Tree Method. A given portion of the forest is cut clear 

 except for seed trees left singly or in groups for furnishing seed to 

 restock the area naturally. This method may be combined with 

 method 1 just described. It is applied to and results in even-aged 

 forests represented by ages within a range of 10 to 20 years. After 

 natural regeneration is secured and the little trees develop, it may 



result in a two-storied forest, 

 the seed trees forming the upper 

 story and the reproduction the 

 understory. 



Only up to 10% of the 

 volume of the stand is generally 

 left in seed trees. These trees 

 should be wind-firm and not 

 susceptible to breakage. Tall 

 trees, with large, deep, open- 

 foliaged crowns should be left 

 for seed purposes. Healthy, 

 vigorous specimens make the 

 best seed trees. Only a few 

 trees of light seed need be left, 

 and several of those with heavy 

 seed. From 1 to 10 seed trees 

 per acre should be left, depend- 

 ing upon local circumstances 

 and the character of the species. 



FIG. 51. Illustration of clear cutting 

 with individual Norway pine seed trees. 

 Huron National Forest, Michigan. Ex- 

 cellent reproduction secured from the 

 mother trees. 



The State of Louisiana requires 

 an average of two seed trees 

 10" d.b.h. per 10-acre area when 

 private timber is logged. In New 

 Hampshire at least one 10" wind-firm white pine tree of good crown 

 must be left on each acre cut of this species. The seed-tree method 

 is applied generally to the entire southern pine region. It is also used 

 in many sections of the West. 



3. Shelterwood Method. This involves the removal of the stand 

 by a series of partial or progressive cuttings. Natural reproduction 

 starts under the protection of the older trees. By careful cuttings, 

 the crowns are enlarged and seed production is stimulated. When a 

 good young growth is established on the forest floor, the last trees 

 in the stand are finally removed. It is adapted to even-aged stands. 

 Reproduction cuttings may extend over a period of 40 to 60 years. 

 The regeneration period is generally between 10 and 20 years. As the 



