And again, as with trees, let no one fear to have a forest cut off when its time comes. Forest trees were made for use and if they are not used as they mature, nature will get rid of them by decay. That this must be so will appear when one observes that in any piece of native woods room is made for young trees by the fall of old ones that have lived their term.
Nature clothed most of the habitable earth with forests of one kind or another and evidently meant that they should serve mankind. This they do by furnishing wood for shelter and for warmth (seven-eighths of the people of the world still use wood for fuel), by providing grateful shade in summer and protection from cold winds in winter, by preventing the soil on steep hillsides from being lost by erosion, by regulating the flow of streams. The contention that forests cause rainfall, or materially influence the climate of a country, is not established. The weight of evidence indicates that forests thrive in proportion to the rainfall rather than that the rain falls in proportion to the extent of forests. And in respect to stream flow we must distinguish between a mountainous or hilly country and a country that is flat; and whether the rain commonly falls in brief, heavy storms or in frequent gentle showers. For instance, we can say with assurance that in North Jersey a forested watershed will discharge a purer, more regular stream than one that is unforested, while in South Jersey the influence of the forest upon the streams is negligible.
As the climate of New Jersey is much the same in all parts, the character of our forests is determined chiefly by soil conditions. Fortunately we have a great diversity, and between the northern and southern sections, strong contrasts. The line separating these sections is nowhere sharply defined but is commonly assumed to run more or less irregularly from Long Branch to Salem.
The forests of North Jersey, supported by soils of considerable fertility, are almost universally of the mixed hardwood type common to the greater part of the central United States east of the Mississippi River. That is, they are composed of a variety of deciduous trees in which are many oaks, chestnut, beech, several maples, ashes, hickories, elms, birches, etc. As exceptions or variants to the type are swampy areas in which black spruce and hemlock are dominant, and sterile mountain crests bearing the pitch pine and scrub oak of the poorest South Jersey sands. This kind of forest, in which each species occupies the position to which it is best adapted, and from which therefore all competitors are excluded, is considered by ecologists the most highly developed vegetable society.
