- Tytuł:
-
Inwentaryzacja martwego drewna statystyczną metodą reprezentacyjną z zastosowaniem warstw gatunkowo-wiekowych
Inventory of deadwood by the means of a statistical representative sampling method using species-age layers - Autorzy:
-
Bujoczek, L.
Bujoczek, M.
Banaś, J.
Zięba, S. - Powiązania:
- https://bibliotekanauki.pl/articles/989002.pdf
- Data publikacji:
- 2017
- Wydawca:
- Polskie Towarzystwo Leśne
- Tematy:
-
lesnictwo
drewno martwe
miazszosc drewna
zasoby drzewne
szacowanie zasobow
metody statystyczne
typy siedliskowe lasu
gatunki panujace
wiek drzewostanu
coarse woody debris
snags
measurements
accuracy - Opis:
- According to the current forest management manual, deadwood volume should be evaluated on 10% of sampling plots, located in different species−age layers, which are used for determining stand volume in a given forest unit. Sampling plot size differs depending on tree stand age and ranges from 0.005 to 0.05 ha. The results are reported for the entire forest district and by forest site type. The objective of the study was to analyze the accuracy of deadwood volume estimations in the light of the guidelines stipulated in the forest management manual and to find the ways to improve the obtained results. Deadwood volume was measured on 2752 sample plots used to determine stand volume and the mean value calculated on that basis was 5.4 m³/ha. Subsequently, 30 random draws of sampling plots were performed. Estimates based on randomly selected pools consisting of 10% of sampling plots ranged from 3.5 to 8.6 m³/ha. Subsequently, another 10% of sampling plots were randomly drawn and added to the previous ones. The results for 20% of sampling plots were 4.5−7.0 m³/ha, for 30% – 4.3−6.4 m³/ha, for 40% – 4.6−6.4 m³/ha and for 50% – 4.7−6.0 m³/ha. In the next step, 225 sampling plots located in reserves and special zones around the nests of protected species were discarded. The mean volume of deadwood computed for the managed forest areas alone (2527 sample plots) was 4.7 m³/ha. The random drawing procedure was repeated to give the following results: 3.6−6.8 m³/ha for 10% of sampling plots; 3.8−5.8 m³/ha for 20%; 3.9−5.3 m³/ha for 30%; 4.2−5.3 m³/ha for 40%; and 4.2−5.1 m³/ha for 50% of sampling plots. The categorization of the randomly selected sampling plots by forest site type in most cases yielded results significantly differed from the values computed based on all sampling plots. It was found that estimates based on 10% of sampling plots may diverge considerably from true values due to the uneven distribution of deadwood. In particular, managed and unmanaged forest areas should not be combined due to the high differences in the volume of deadwood between them. If a relatively low number of sampling plots is used, it seems advisable to report results only for the forest division as a whole, without a breakdown into site types. Satisfactory estimates for the different forest sites types would require much more work. The use of a greater number of sampling plots than specified in the forest management manual seems to be a fundamental prerequisite for improving the accuracy of deadwood volume estimates.
- Źródło:
-
Sylwan; 2017, 161, 02; 114-123
0039-7660 - Pojawia się w:
- Sylwan
- Dostawca treści:
- Biblioteka Nauki
Artykuł