THE CANADIAN HORTICULTURIST. 



161 



in very severe weather. In April the 

 frame should be revei-sed from south to 

 nortli, thus avoiding the full glare of the 

 sun, which is very important. To keep 

 up a good variety, the best seed should 

 be selected, and each color should be 

 marked separately. — -Discussions of the 

 Massanhxi setts Horticultural Society. 



IMPORTANCE OF ECONOMIZING AND 

 PRESERVING OUR FORESTS. 



By William Saunders. 

 (From the Transaction of (he Royal Society of Canada.) 



At fii-st sight, forests appear to the 

 settler in a wooded country as ob- 

 stacles to advancing civilization, to be 

 removed as rapidly as possible, and 

 with unwearied zeal and persistence in 

 the use of axe and fire the encumbrances 

 are soon disposed of. The stock of fer- 

 tility Mccumulated by the long con- 

 tinued annual fall and decay of the 

 leaves is utilized in the growth of cer- 

 eals for man's sustenance, and in his 

 zeal to get rid of the trees, the owner 

 seldom reflects on the inestimable value 

 of woods in providing shelter against 

 storms, in equalizing temperature and 

 moisture, and in pui'ifying the atmos- 

 phere. 



Perhaps the most ob^'ious modifica- 

 tion of climate by forests is in arresting 

 wind, .subduing its power in a greater 

 degree than a solid barrier would, the 

 limbs entangling and killing its force in 

 a marked degi-ee. Even a single tree 

 has a w;tke of calm stretching away to 

 a considerable distance, while a forest 

 of deciduous trees absolutely arrests 

 the wind near the earth. A windy cli- 

 mate is generally an unhealthy one, as 

 indicated by the marked increase in 

 mortality during and following the long 

 continued prevalence of cold winds. 



Forests also equalize violent alterna- 

 tions of heat and cold ; the tempera- 

 ture is lower in summer and higher in 

 winter in the forest than in the adja- 

 2 



cent open ground. During the heated 

 term the umbrageous foliage protects 

 the soil from the direct action of the 

 sun's rays, while every leaf by the 

 evaporation of moisture from its sur- 

 face acts as a refrigerator on the air 

 immediately adjacent. In winter the 

 heat which has been absorbed by the 

 water with which the soil is chai'ged 

 also by the earth is slowly given up, 

 and, added to the minute quantity of 

 heat given forth by the living trees 

 themselves, forms a reservoir of warmer 

 air, which is slowly displaced in severe 

 weather and mitigates its severity ; in- 

 deed the forest is a treasurer of the ele- 

 ments of climate, hoarding excesses and 

 distributing in times of need. 



Forests also exercise a governing and 

 conservative influence on the humidity 

 of the atmosphere. The roots of trees 

 act in a measure like conduits, admitt- 

 ing the rain water into the sub-soil, 

 while over this lies a stratum of humua, 

 highly absorbent, and on the surface a 

 layer of decaying trees, the whole act- 

 ing something like an enormous sponge 

 holding a vast quantity of surface 

 water reserved for the heated season. 

 Then, when the need for it is most 

 urgent, it is elevated to the upper sur- 

 face and distributed to the parched air 

 by evaporation from the leaves, as 

 already stated. 



Forests also influence rainfall ; trees 

 indeed are most singularly complicated 

 condensers, their limbs, boughs and 

 leaves being a soi-t of natural machinery, 

 wonderfully adapted to the purpose of 

 grasping upon the atmosphere and 

 causing those dynamic changes which 

 induce precipitation of moisture. 



Trees purify the soil. The pollution 

 constantly going on about our dwellings 

 charges the soil with organic matter, 

 which the roots of trees search out, fol- 

 low and feed upon, and alter it as com- 

 pletely as if it were burnt, and elevate 

 it into the upper air in forms of beauty. 



