Cargando…
Consistency of defoliation data of the national training courses for the forest condition survey in Germany from 1992 to 2012
The consistency of visual assessment of tree defoliation, which represents the most widely used indicator for tree condition, has frequently been in the focus of scientific criticism. Thus, the objective of the present study was to examine the consistency of the defoliation data from the annual nati...
Autores principales: | , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Springer Netherlands
2013
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3857523/ https://www.ncbi.nlm.nih.gov/pubmed/23955498 http://dx.doi.org/10.1007/s10661-013-3372-3 |
_version_ | 1782295172134993920 |
---|---|
author | Eickenscheidt, Nadine Wellbrock, Nicole |
author_facet | Eickenscheidt, Nadine Wellbrock, Nicole |
author_sort | Eickenscheidt, Nadine |
collection | PubMed |
description | The consistency of visual assessment of tree defoliation, which represents the most widely used indicator for tree condition, has frequently been in the focus of scientific criticism. Thus, the objective of the present study was to examine the consistency of the defoliation data from the annual national training courses for the forest condition survey in Germany from 1992 to 2012. Defoliation assessments were carried out in stands of beech (Fagus sylvatica), oak (Quercus robur and Quercus petraea), Norway spruce (Picea abies), and pine (Pinus sylvestris). Among the observer teams, the absolute deviation from the observer mean of all years was ±4.4 % defoliation and the standard deviation of defoliation was ±5.5 %. On average, 94 % of the assessments were located within the ±10 % interval of deviation from the mean. Tree species-specific differences did not occur when all years were considered. A trend towards increasing consistency was observed from 1992 to 2012, in particular for oak and spruce. The deviation of defoliation assessments depended non-linearly on the level of defoliation with highest deviations at intermediate defoliations. In spite of high correlations and agreements among observers, systematic errors were determined in nearly every year. However, within-observer variances were higher than between-observer variances. The present study applied a three-way evaluation approach for the assessment of consistency and demonstrated that the visual defoliation assessment at the national training courses in general produced consistent data within Germany from 1992 to 2012. |
format | Online Article Text |
id | pubmed-3857523 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2013 |
publisher | Springer Netherlands |
record_format | MEDLINE/PubMed |
spelling | pubmed-38575232013-12-11 Consistency of defoliation data of the national training courses for the forest condition survey in Germany from 1992 to 2012 Eickenscheidt, Nadine Wellbrock, Nicole Environ Monit Assess Article The consistency of visual assessment of tree defoliation, which represents the most widely used indicator for tree condition, has frequently been in the focus of scientific criticism. Thus, the objective of the present study was to examine the consistency of the defoliation data from the annual national training courses for the forest condition survey in Germany from 1992 to 2012. Defoliation assessments were carried out in stands of beech (Fagus sylvatica), oak (Quercus robur and Quercus petraea), Norway spruce (Picea abies), and pine (Pinus sylvestris). Among the observer teams, the absolute deviation from the observer mean of all years was ±4.4 % defoliation and the standard deviation of defoliation was ±5.5 %. On average, 94 % of the assessments were located within the ±10 % interval of deviation from the mean. Tree species-specific differences did not occur when all years were considered. A trend towards increasing consistency was observed from 1992 to 2012, in particular for oak and spruce. The deviation of defoliation assessments depended non-linearly on the level of defoliation with highest deviations at intermediate defoliations. In spite of high correlations and agreements among observers, systematic errors were determined in nearly every year. However, within-observer variances were higher than between-observer variances. The present study applied a three-way evaluation approach for the assessment of consistency and demonstrated that the visual defoliation assessment at the national training courses in general produced consistent data within Germany from 1992 to 2012. Springer Netherlands 2013-08-18 2014 /pmc/articles/PMC3857523/ /pubmed/23955498 http://dx.doi.org/10.1007/s10661-013-3372-3 Text en © The Author(s) 2013 https://creativecommons.org/licenses/by-nc/2.0/ Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited. |
spellingShingle | Article Eickenscheidt, Nadine Wellbrock, Nicole Consistency of defoliation data of the national training courses for the forest condition survey in Germany from 1992 to 2012 |
title | Consistency of defoliation data of the national training courses for the forest condition survey in Germany from 1992 to 2012 |
title_full | Consistency of defoliation data of the national training courses for the forest condition survey in Germany from 1992 to 2012 |
title_fullStr | Consistency of defoliation data of the national training courses for the forest condition survey in Germany from 1992 to 2012 |
title_full_unstemmed | Consistency of defoliation data of the national training courses for the forest condition survey in Germany from 1992 to 2012 |
title_short | Consistency of defoliation data of the national training courses for the forest condition survey in Germany from 1992 to 2012 |
title_sort | consistency of defoliation data of the national training courses for the forest condition survey in germany from 1992 to 2012 |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3857523/ https://www.ncbi.nlm.nih.gov/pubmed/23955498 http://dx.doi.org/10.1007/s10661-013-3372-3 |
work_keys_str_mv | AT eickenscheidtnadine consistencyofdefoliationdataofthenationaltrainingcoursesfortheforestconditionsurveyingermanyfrom1992to2012 AT wellbrocknicole consistencyofdefoliationdataofthenationaltrainingcoursesfortheforestconditionsurveyingermanyfrom1992to2012 |