No abstract

Growth of the most widely distributed pine in North America is under joint study by the western Forest and Range Experiment Stations of the U. S. Forest Service. Young, even-aged ponderosa pine (Pinus ponderosa Laws.) stands are being examined over a wide range of tree sizes, stand densities, and site index. The single plan that coordinates activities of the four Stations is an example of how the growing stock problem can be handled for a widely distributed species. The wide range in treatments should provide data needed to answer the questions that arise in evaluation and application of multiple use management of ponderosa pine forests. i itensified management of ponderosa pine for wood products depends on control of growing stock. Such control will permit actual yields of the coast form of ponderosa pine to approach its high potential. The interior form of ponderosa pine occurs in areas of lower site quality, and much of it is subject to stagnation. Saw-log rotations of some dense, young stands may be shortened 60 to 80 years by thinning. Growing stock can be controlled most effectively if stand productivity can be forecast for various combinations of such factors as tree size, stand density, and site quality.

The distribution of soil nutrients around nest entrances of the ant Aphaenogaster barbigula was studied in a semi-arid woodland in eastern Australia. The ants re-excavate their nest chambers after rainfall, trapping any litter which falls near the entrance, and blocking the passage of litter moving downslope by processes of overland flow. The entrapment of organic matter around nest entrances resulted in significantly higher levels of nitrogen, organic matter, and some cations compared with nest-free surfaces. Significant depth nest interactions suggest that these nutrients are being concentrated close to the surface.

Volumes are in total cubic feet and cubic feet to a 4.0-inch top, board feet Scribner Rule to 6-inch and 8-inch tops, and board feet International^-inch Rule to 6-inch and 8-inch tops. Tree heights are in feet and numbers of logs. Volume equations are of the form V = a + bD 2 H.

Presents silvicultural prescriptions for ponderosa pine in an area where several uses and products of the forest are important but scenic and recreation values predominate. Although far from virgin condition, the pine stands now bear little resemblance to a managed, regulated forest. Present diversity within and between vegetative types can and should be maintained.