- Tytuł:
-
Dokładność określenia zasobności na poziomie warstw gatunkowo-wiekowych w obrębowej metodzie inwentaryzacji
Accuracy of volume determination on the level of age-species layers in the stratified sampling method - Autorzy:
-
Banaś, J.
Drozd, M.
Bujoczek, L.
Zięba, S.
Zygmunt, R. - Powiązania:
- https://bibliotekanauki.pl/articles/986687.pdf
- Data publikacji:
- 2017
- Wydawca:
- Polskie Towarzystwo Leśne
- Tematy:
-
powierzchnie probne
forest inventory
stratification
standard error
sample plot
variability coefficient
lesnictwo
drzewostany swierkowe
warstwy gatunkowo-wiekowe
inwentaryzacja lasu
zasobnosc drzewostanu
miazszosc drzewostanow
metoda obrebowa
dokladnosc pomiaru - Opis:
- Statistical representative method of inventory based on stratified sampling is used for elaborate forest management plans in Poland. Strata are created according to the dominant tree species and age of stands. First stratum include stands with age from 21 to 30 years and the interval in the next strata is 10 years. Sample plot size depends on stand age and varies from 0.005 to 0.05 ha. According to the allocation pattern number of samples is proportional to age and total area of stands in a stratum. Diversification of number and size of sample plots has a profound influence of inventory precision in an age classes. The aim of the study is to analyse the accuracy of the stand volume determination on the level of age−species strata. Research was conducted based on the data obtained from periodic forest inventory in seven mountainous forest subdistricts located in the Kłodzko Basin (SW Poland). Norway spruce stands with total area of 39,935.45 ha and 6102 sample plots were chosen for analysis. Sampling fraction, mean number and volume of trees on a sample plot, coefficient of volume variability and standard error of volume were calculated for each stratum in analyzed forest subdistricts. Sample plots with size of 0.005 ha established in young stands (21−30 years) are characterized by small number of trees (4.3−7.6 in average) and the highest coefficient of volume variability (93%). Additionally, because of low age of stands, the number of plots is also small (18 on average), which influences the low precision of volume inventory in this stratum. Standard error of volume was on the mean level of 23% in the youngest age stratum and decreased with age of stands to 5% in the stands of 41−71 years and below this level in the strata with the older stands. Increasing the plot size in the youngest stratum will be effective way to improve accuracy of forest inventory in the method based on stratified sampling.
- Źródło:
-
Sylwan; 2017, 161, 09; 715-722
0039-7660 - Pojawia się w:
- Sylwan
- Dostawca treści:
- Biblioteka Nauki
Artykuł