Different Types Of Vegetation Research Articles

Microclimate and a Notable Case of Its Influence on a Ridge in Central Indiana

The term microclimate or habitat climate has become well established in European literature but American workers have used it very sparingly. Mlicroclimate refers to the finer modifications of the imiacroclimate or climate in the broader sense in which it is used in meteorology. While vegetation in its gross aspects is determined by the macroclimate, the microclimate is the real plant climate and plant association determiner, for the very presence of plants means modification of the purely gross meteorological climate conditions. Geiger ('30) says, That microclimate differs greatly from the records of the weather station reports has been known for a long time, as for instance the variation in the occurrence of frost within the narrow confines of a certain locality, but how great and extensive these divergencies may be in this special climate near the earth's surface has been discovered only recently through numerous measurements, and there are without doubt, still many surprises in store for us, for the moisture relationships have hardly been touched in a microclimatic way. He sums up the problems by saying, The goal of the investigation in microclimatology must be to attempt to discover the physical laws which govern the deviations of the microclimate from the macroclimate. Microclimatology will give us a better understanding of atmospheric happenings. He believes that in densely populated areas it is almost more important to know the existing microclimatic variations than those of the generalized macroclimate. These variations are certainly important in the analysis of minor and at times of major differences in vegetation types, and in forestry and agricultural experiments, and here in Indiana in solving of the soil erosion problem. Many variations in microclimate are due to topographic differences, as Cowles ('01) has shown, but microclimate involves more than mere variation in topography. Of importance also are structure, color, aeration and wvaterholding capacity of soil, reaction of plant cover on the habitat, differences in erosion and run-off. One must also include not easily defined variations in temperature and precipitation in regions with apparently small physiographic and topographic variations which Visher ('36) has described for Indiana. Indiana as a whole is a rather uniform plain, yet its climate is not so uniform, even in the same latitude, as is usually assumed. Visher ('36, '37)