16 



AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS. 



appear along the streams or on natural elevations of sandy, porous soiL 

 These patches become larger farther north, gradually forming extensive 

 bodies of timber, until finally the prairie gives way to a continuous- 

 forest of loblolly pine and hardwoods, except where land has been cleared 

 for rice and other crops. Along the southern border the forest tends 

 to succeed the prairie in the process of reclaiming marsh land areaa 

 and, except along the larger streams, this forest is of comparatively recent 

 development. The islands of timber show older growth in the center 

 and younger growth around the edges. Prairie fires are the chief ob- 



Map 6 East Texas Timber Belt. 



1 Longleaf pine region. 2 Shortleaf pine region. 3 Loblolly pine region. 



4 Main body of post oaks. 5 Eastern cross-timbers. 6 Western 



cross-timbers. 7 Central Mineral region. 



stacle to the more rapid enlargement and extension of these forest islands 

 which usually have their beginning in pure stands of loblolly pine. As 

 the stands become more open, hardwood species creep in to form mixed 

 types, such as are found along the rivers and lands adjacent to them, 

 known as "river swamps," and in depressions on the higher uplands, 

 known as "bay galls." Pure stands of loblolly pine on old fields are 

 less common in Texas than in loblolly pine regions of other Southern 

 States, where large areas were in cultivation many years ago and have 

 since been abandoned. 



Loblolly pine is primarily a tree of the lowlands which border the 

 swamps and streams. Where the soil is poor and sandy but quite moist 



