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最初由Leva和Madden研制的点框(1933)经过不同的改良,现已证明这些改进对获得足够的样品数量而多点多次取样是需要的。本报告描述的点框,有助于获得足够的样品数。装有可刺入土壤的测针,并在同一不变的样方框内读数的钢制样方已获得数年了(Gox 1977)。框和测针能重新安装,位置变化不超过2-3毫米。该装置在怀俄明州东部的矮草草原生态系统进行了试验,那里大部分是低草,植基和叶子覆盖率容易用点的资料数量化。
The dot-matrix (1933), originally developed by Leva and Madden, has undergone a number of different modifications and these improvements have been shown to be necessary for multiple samples multiple times to obtain a sufficient sample size. The point boxes described in this report help to get enough samples. It has been around for years that steel prototypes with stylus penetrating the soil and reading in the same constant quadrilateral (Gox 1977). Box and stylus can be re-installed, the location change does not exceed 2-3 mm. The plant was tested in the weever grassland ecosystem in eastern Wyoming, where most of the grass is low-grained and the leaf cover and leaf coverage are readily quantified using point data.