268 NEBRASKA STATE HORTICULTURAL SOCIETY 



HOW TREES LIVE AND DIE. 

 Secrets of Their Growth From Green's Fruit Grower. 



Whenever man reaches a full realization of the importance of the 

 proper treatment of trees our trees will become "a thing of beauty and 

 joy forever." In a current issue of the New York Commercial we find this 

 splendid treatise on the tree. It says: 



Trees literally, breathe, inhaling oxygen and exhaling carbonic acid 

 gas. The leaves are the lungs of the tree. On the lower surface of the 

 leaf are vast multitudes of minute mouths or openings (100,000 to the 

 square inch, it is estimated) which admit the air and expel the carbon. 



There are other openings, called lenticels, in the bark, dots and lines 

 which can be easily seen on the twigs and smooth branches, which help 

 the leaves just as the pores of the skin help the lungs. The perspiration 

 of plants is technically known as transpiration. 



The exhalation of water from the leaves is very great. That from 

 a large oak is estimated at 150 gallons a day during the summer. The 

 evaporation of water from the forests is fully as important as that from 

 the ocean, if not more so. The ocean alone could not produce rain enough 

 to sustain vegetation. 



The roots also are active in taking oxygen from the air, which is 

 always active in porous soil. A tree may be smothered by piling earth 

 on its roots or hardening the soil around them, says the Christian In- 

 telligencer; it may be drowned by keeping its roots water-soaked. Coal 

 gas will choke it. 



The tip ends of the tree roots absorb moisture from the ground, even 

 in zero weather, but the passage of water from the roots up the trunk is 

 retarded until winter relaxes its hold. The largest roots anchor the 

 tree to the soil and do but little else. The slender rootlets and the tips 

 of the large roots collect all that part of the tree's food which comes from 

 the ground. 



Trees eat and drink through the leaves and the rootlets. While 

 they breathe all the time, day and night, rain or shine, as steadily as we 

 do, they feed only part of the time. They sleep in the night, during 

 rainy weather and throughout the winter. The growing season is very 

 short, ending by midsummer. The summer drouths cut off or diminish 

 the supply of water. The leaves are battered and eaten by insects. 



A long period of rest is essential that twigs may harden and the 

 wood ripen. Careful preparation for winter takes the place of further 

 thickening of the trunk or lengthening of the limbs. The twigs and 

 stems and roots must be stocked with food. The tree strives to take in 

 all the nutritious parts of each leaf before it casts it off. When winter 

 comes it generally finds the tree ready. The lenticels are sealed during 

 the winter to prevent the breathing away of the tree's moisture. 



Each leaf is a laboratory, where minerals and gases, water and 

 sunshine are made into nourishment for the living tissue, from which 

 comes wood, cork, flower, fruit, and a large number of gums, oils, essences. 



