TITLE:
Size and Shape of Sample Units in Native Forests and Plantations
AUTHORS:
Sylvio Péllico Netto, Julio Cesar Rodriguez Tello, Rafael Romualdo Wandresen
KEYWORDS:
Optimization of the Size of Plots, Sampling of Fixed Area, Efficiency per Day of Work, Mixed Tropical Forest
JOURNAL NAME:
Open Journal of Forestry,
Vol.4 No.4,
July
31,
2014
ABSTRACT: The size
and form of sampling units-SU have always been variables considered in planning
and structuring forest inventories, being performed in forests or in
plantations. The experimental work outlined to deal with the problem was
conducted in an area of araucaria forest, in Sao Joao de Triunfo, PR, Brazil.
The forms of sampling units circle, square and rectangular were evaluated, whose
areas ranged from 200 m2 to 1000 m2. Time was recorded
using a stopwatch and computed separately for locomotion and measurement. The
power model was used to adjust the relations of the times of locomotion and
measurement, as well as a hyperbolic one for the coefficient of variation, all
taking as function of the SUs sizes. To achieve the analytical solution for the
optimum size of the SU, it was necessary simulating the behavior of the three
functions until the size of 10,000 m2. By taking the derivative of
the combined function it was found the maximum point, which allowed optimizing
the size of the SU in 600 m2 for the structured experimental
conditions. This result proved the formulated hypothesis, performing even a
critical analysis of the inclusion of other relevant variables, such as size of
the area to be inventoried, number of SUs performed in one day of work, average
distance between the SUs, average speeds for locomotion between SUs and for
taking all respective measurements.