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Pubblicazioni Scientifiche
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Pubblicazioni per anno
Checking the performance of point and plot sampling on aerial photoimagery of a large-scale population of trees outside forests
Fattorini
,
Lorenzo
,
Puletti
,
Nicola
,
Chirici
,
Gherardo
,
Corona
,
P.
,
Gazzarri
,
C.
,
Mura
,
Matteo
,
Marchetti
,
Marco
tessellation stratified sampling
two-phase sampling
design-based estimation
one-per-stratum stratified sampling
Mostra abstract
The present study investigates some sampling strategies for the estimation of abundance and canopy cover of trees outside forest (TOF) over large areas. A collection of about 53 000 TOF units in Central Italy was acquired by visual, on-screen interpretation of aerial orthophotos and was taken as the reference population with the purpose of investigating: (i) one-phase inventories with sample points located by means of the tessellation stratified sampling (TSS), which involves covering the study region by a grid of regular polygons of equal sizes and randomly and independently selecting a point in each of them; (ii) two-phase inventories with the one-per-stratum stratified sampling adopted in the second phase to select a sample of polygons from the grid and then visit only the points contained in those polygons. Uniform random sampling is also considered in the first phase as a benchmark for tessellation stratified sampling. The sampling schemes adopted to select TOF units at the sample points are as follows: (i) point sampling, (ii) centroid-based plot sampling with plot radius of 50m(CPLS50) or 100 m, and (iii) plot intersect sampling with plot radius of 50 or 100 m. CPLS50 under single-phase TSS proves to be a promising strategy to large-scale TOF inventories. © 2016, Canadian Science Publishing. All rights reserved.
Exportability of options and results to other forests
F. Ferretti
,
M. Čater
,
P. Cantiani
,
U. Di Salvatore
,
U. Chiavetta
,
C. Becagli
,
F. Mason
,
L. Zapponi
,
G. Fabbio