24 Characteristics, Structure, Life of Trees 
such a wide range of distribution, through such a variety of 
climates, that the success depends upon the choice of the 
locality from which the plant has been derived or from which 
the seed has been secured, for the seed preserves all the 
characteristics of its mother plant. A case in point is the 
Douglas Fir, ranging from British Columbia to New Mex- 
ico. Plants of this species, when brought from the humid, 
mild Pacific Coast do not thrive in the drier, severer climate 
of the Eastern States; but if grown from seed collected in 
the dry Rockies, they will succeed. 
It must also be kept in mind that there is considerable 
variation of climate experienced locally within narrow 
limits, as for instance, in going from the foot to the top of a 
mountain, or with change of aspect, and with different 
exposure to winds. Hence the tree in one place may find 
satisfactory environment, when in close neighborhood, 
but in a different situation, it may not: the south side of a 
town is warmer, the northwest colder, but healthier, the 
southeast most equable, and so on. 
While, therefore, the fact that different species of trees 
are by nature adapted to certain climatic conditions must 
influence the choice of trees for planting in a given locality, 
and while the natural adaptation of species to deep or 
shallow, wet or dry soils is also a matter to be considered in 
the selection of plant material, we know that soils at least 
can be adapted to support any tree species and also that the 
light conditions can, to some extent, be made favorable to 
the needs of the species adapted to the climate. 
There is one condition of soil which is most favorable 
to all tree species, namely, a deep, moderately loose, 
sandy loam, which permits satisfactory aération and fur- 
nishes an even water supply. When we speak of trees 
adapted to other, drier or wetter, more compact or looser, 
