Soil Moisture Fluctuations Under Two Ponderosa Pine Stands In Nothern Arizona

Soil moisture, or the lack of it, is of great significance in the complex of factors that influence tree growth. A knowledge of soil-moisture fluctuations can lead to a better understanding of tree growth, of seedling establishment, and of effective rainfall. Soil moisture is one important step closer to the physiological regime within the plant than is the rain that falls upon the soil surface. The purpose of the work here described was to trace the course of soil-moisture fluctuations for a minimum interval of 3 years at two dissimilar stations within the ponderosa pine forest of north-central Arizona.