Quantifying the effect of sampling plot size on the estimation of structural indicators in old-growth forest stands

摘要: Abstract There is increasing awareness that structure-based indicators should be considered for assessing the biological value of late successional forests. In order to increase unique habitat features critical old-growth associated species, it important identify and rank candidate potential forest sites on basis their distinctive structural features. Data living deadwood components identification condition are usually acquired in stands by two sampling survey: (i) census performed relatively large monitoring sites; (ii) network small units, which inventory practices based. Several authors argued choosing between these survey strategies might have substantial effects values common condition. Our study aims at total estimate differences among measured field plots with different sizes, defining optimal sample size reliable assessment such indicators. The was carried out six beech dominated Apennines range Italy. each stand, were surveyed geocoded 1-ha square areas. Based dataset, circular radii ranging from 4 m up 20 m then quantify effect plot estimation four indicators: (1) number trees; (2) trees (dbh ⩾ 50 cm); (3) volume; (4) elements (snags, dead standing lying trees, deadwood) dbh (or average diameter ⩾ 30 cm. We found least 500 m2 establish a database investigated approach preferred smaller than 3–5 ha. achieved results contribute define protocols characterizing ranking degree approximate based standardized