Contributions of silvicultural studies at Fort Valley to watershed management of Arizona's ponderosa pine forests

Abstract—Watershed management and water yield augmentation have been im-portant objectives for chaparral, ponderosa pine, and mixed conifer management in Arizona and New Mexico. The ponderosa pine forests and other vegetation types generally occur in relatively high precipitation zones where the potential for increased water yields is great. The ponderosa pine forests have been the subject of numerous research and management activities. Although the size, topography, and drainage patterns of the Fort Valley Experimental Forest are not conducive to watershed-scale hydrologic studies, results from Fort Valley have demonstrated the potential of silvicultural options to increase water yields. These included creating openings of different sizes, shapes, and orientations, or reducing stand densities or combinations of the two. While the importance of managing forests for water yield improvement has declined, it is still a consideration in multi-resource planning. The paper reviews silvicultural prescriptions employed on some of the major watershed research studies within the ponderosa pine forests and discusses their management implications.