FOREST TREE SEED AND SEED COLLECTING 105 



him to believe that autumn seeding with protection from rodents 

 is far more successful than spring seeding because of the difficulty 

 experienced in storing the seed over the winter without excessive 

 loss. The seed of all coniferous species can be safely stored in 

 dried condition over the first winter without serious loss in germi- 

 native capacity. With these species, therefore, in order to lessen 

 the danger from birds and rodents, it is best to sow the seed in the 

 spring just before the season for germination arrives. So also many 

 of our broadleaved species, as illustrated in black locust, sweet 

 gum, and catalpa, can be similarly stored. Many of our hardwood 

 species, however, as in walnut, hickory, oak, chestnut, beech, 

 maple, and ash, should not be stored dry even over the first winter. 

 When stored in dry bins at the normal atmospheric temperature 

 and humidity, they suffer from desiccation and completely lose 

 their germinating power; or else, when sown, lie over until the 

 second year. When it is not expedient to sow seeds of this char- 

 acter immediately after gathering, they should be stored under 

 conditions that prevent undue desiccation. 



12. VARIATION IN THE KEEPING QUALITIES IN 

 DIFFERENT SPECIES 



Many forest trees retain their fruit on the tree without casting 

 the seed for long periods after maturity. The seed of these spe- 

 cies can be stored dry, often for a period of several years, without 

 apparent loss in germinative capacity. Thus black locust and 

 catalpa do not cast their seed until late winter or early spring 

 following their maturity. A number of conifers as illustrated in 

 jack pine, lodgepole pine and Monterey pine, often retain their 

 fruit for ten years or more after ripening. The seeds of these 

 species keep remarkably well without loss in viability. 



The seeds of different species exhibit a remarkably wide range 

 in keeping qualities. The control of the moisture or temperature 

 conditions under which the seed is stored, or both combined, ex- 

 tends the time over which seed exhibiting varying degrees of sen- 

 sitiveness to normal conditions can be safely kept. This is well 

 illustrated in white pine seed, which under normal conditions of 

 open, dry storage rapidly loses its viability after the first season, 

 but which can be kept with but little loss in viability in cold 

 storage or when stored in sealed cans or carboys. 



