Articles containing the keyword 'line plot survey'

The article is a lecture given by A.K. Cajander in the International Congress of Plant Science. The lecture describes results of Finnish forest research that might be regarded significant also for North America. Because of similarities in nature and forest management, forest research may use similar methods in both areas.

For instance, line plot survey in the form used in Finland could well be applied in North America. In Finland, lines were drawn at 26 kilometer intervals. Visual estimates about, for instance, species, tree growth and productivity class, were made along the lines and sample plots were taken every other kilometer. To gain full advantage of the method, a productivity classification and yield tables are needed. When these are known, it is possible to find out how to increase the productivity of forests with suitable tree species and proper forest management. This kind of inventory of forest resources and the state of forests provides reliable information for forest policy. Another important issue for forest research is forest management, which requires understanding on their biology. At the same time, research must provide methods for practical forestry.

A summary in Finnish is included in the PDF.

• Cajander, E-mail: ac@mm.unknown

Line plot survey has proven the best method to assess forest resources in the Northern countries on a country level; it is cost effective and gives reliable results. The accuracy of the survey depends on, however, how close the lines are set. To get homogenous statistics of an entire country, the survey should not span over too long a period. Thus, the distance between the lines should be chosen wide enough to give accurate results quickly for the whole country, while accepting slightly less exact results for its smaller districts.

If line survey is performed on large areas, it is not possible to count and measure trees, measure the tree growth. etc. along the whole length of the line because of its costs. Therefore, more precise measurements are limited to sample plots, which are spaced evenly along the lines. Between the sample plots, the volume and growth of each stand touching the line are estimated visually. These visual estimates have often systematic faultiness, which can be eliminated with correlation calculations. Visual observations gather information, for instance, about land owner, soil type, land-use class, forest site type, tree species and age class of the stand, density, wood volume ja annual growth per hectare, and the current silvicultural state of the stand. With help of this kind of information it is possible to get sufficient statistics about the forest resources of a country.

A summary in Finnish is included in the PDF.

• Ilvessalo, E-mail: yi@mm.unknown