We established a 36.25 ha research plot in the Tokyo University Forest, Hokkaido, in order to clarify the life history of trees and the dynamics of tree populations and forest communities. Because trees are large and have a long lifespan, research plots should be large enough to allow studies of tree populations and stand communities. We therefore introduced a technique for establishment of mixed forest zones. The research plot is located in a 1,200 ha reserve forest. It has experienced little disturbance such as cutting, and is positioned on an eastern slope between 550 and 1,459 m a.s.l. The plot has a side road for easy access of research workers. The north-south border of the plot is 1,300 m long and the east-west border is 400 m long. The elevation ranges from 622 to 680 m a.s.l. The plot is divided into 145 quadrats of 50×50 m according to the plane rectangular coordinate system of Japan for geological information systems. The mesh was carefully surveyed to ensure that the area was accurate for future data analyses. First, we surveyed a baseline and created 51 base points using a theodolite between two known air-photo signals through a forest road. Next, we measured grid points from the base points as a closure survey. For identification, each tree was tagged with a stainless steel plate bearing an ID number using vinylcoated copper wire attached to a stainless steel nail. The total work took 432 man・days and cost \1,450,000 in expendable supplies. In the plot, we counted 24,921 stems and 35 tree species with a d.b.h. larger than 5 cm except for climbers. We are planning to measure the d.b.h. every five years, to create a tree distribution map and to census seedlings and saplings.
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