Monitoring changes in timber volume using aerial photo plots and field plots in a two-phase sampling design.

Authors

  • D.A. Stellingwerf
  • A. de Gier

DOI:

https://doi.org/10.18174/njas.v36i2.16685

Abstract

Standing timber volume and mean periodic volume increment (of Norway spruce - Picea abies - age 40-100 yr) were determined over a period of 10 yr (1974-84) in a 3000 ha forest area in Austria. The results of a Two-Phase Linear Regression Sampling (TPLRS) method (using 112 circular photo plots in the first phase, and 55 dependent field plots in the second phase, each covering 0.05 ha) were compared with those of a Simple Random Sample (SRS) of only field plots (112). The crown cover percentages per plot were taken as independent variables in the TPLRS. They were stereoscopically determined on 1:10 000 scale black and white infrared aerial photographs of 1974 and 1984. Results from TPLRS were comparable to those from SRS and did not require re-enumeration of the field plots in 1984. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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Published

1988-05-01

Issue

Vol. 36 No. 2 (1988)

Section

Papers

License

© Copyright KLV All rights reserved. The copyright covers the exclusive right to reproduce and distribute the contribution, including reprints, translations, photographic reproductions, microform, electronic form (offline, online), or any other reproductions of similar nature. The Author may publish his/her contribution on his/her personal Web page provided that he/she creates a link to http://library.wur.nl/ojs/index.php/njas and that together with this electronic version it is clearly pointed out, by prominently adding "© KLV", that the copyright for this contribution is held by KLV. The full-text version may be available from the Author's Web page only after a delay of 12 months following the publication of the paper, whereas such a delay is not required for the abstract.