38 SEEDING AND PLANTING 



the danger of severe injury by the white pine weevil. The black 

 locust can seldom be safely planted because of the damage to the 

 wood by the locust borer. In some sections the hickories are so 

 severely damaged by the hickory borer that they cannot be profit- 

 ably grown for timber. 



One species may be practically free from this source of injury 

 in a given locality, while another otherwise well adapted to the 

 site may be severely injured. In the selection of species for arti- 

 ficial regeneration due consideration must be given to the injury 

 which they are likely to meet from this cause. Insect injury is 

 much greater where a species is grown in pure stand; hence, when 

 a species is grown in a region where it is likely to be infested with 

 insects, it should ordinarily be grown in a mixture with other 

 species not subject to this manner of injury. Thus, in New Eng- 

 land, white pine can be mixed advantageously with red pine, as the 

 latter species is not subject to injury by the weevil. 



30. Fungi. Severe injury to many species of important trees 

 by parasitic fungi prevents their successful use in artificial re- 

 generation in infested districts. The chestnut, which was the 

 most important commercial hardwood in southern New England, 

 cannot be safely planted at the present time owing to its liability 

 to destruction by the chestnut blight. 



31. Grazing. Usually all grazing should be excluded from 

 newly regenerated areas. Among domestic animals, goats and 

 sheep are the most harmful, and horses the least harmful. Even 

 wild animals do great harm to many species. Deer eat the buds 

 and particularly the leaders of coniferous species during the winter. 

 Squirrels do great damage in spruce plantations by destroying the 

 buds. In general, grazing animals are more harmful to broad- 

 leaved species than they are to conifers; although severely injured, 

 broadleaved species usually recover by sprouting while conifers do 

 not. Conifers are usually not eaten by stock where other forage 

 is available; while, on the other hand, most broadleaved species 

 are. Where moderate grazing is continued during the period of 

 regeneration, less damage is likely to occur if pines, spruces, and 

 other coniferous species are used. 



32. Lands Subject to Overflow. Special attention must be 

 given to the selection of species to seed or plant on lands sub- 

 ject to overflow. Upland species should never be planted on 

 such sites, as they are severely injured or killed outright by 



