- Tytuł:
-
Dokładność stałych krzywych wysokości dla drzewostanów olszy czarnej (Alnus glutinosa (L.) Gaertn.)
Accuracy of the uniform height curves for black alder (Alnus glutinosa (L.) Gaertn.) stands - Autorzy:
-
Ochał, W.
Orzeł, S.
Siudak, K.
Zamyślewska, M. - Powiązania:
- https://bibliotekanauki.pl/articles/989648.pdf
- Data publikacji:
- 2016
- Wydawca:
- Polskie Towarzystwo Leśne
- Tematy:
-
lesnictwo
dendrometria
drzewostany olszowe
drzewa lesne
olsza czarna
Alnus glutinosa
piersnice drzew
wysokosc drzew
stale krzywe wysokosci
h−d relationship
uniform height curve
forest inventory
black alder - Opis:
- The study presents the assessment of the accuracy of two generalized height−diameter models, such as skwB [Bruchwald et al. 2001] and skwO [Orzeł et al. 2014], developed in Poland for black alder (Alnus glutinosa (L.) Gaertn.) stands. Verification of these models was conducted on empirical material that was collected in 127 alder stands located in the western part of Sandomierz Basin (southern Poland). Selected alder stands aged 6−89 years, while average breast height diameter ranged from 4.5 to 43.0 cm and average height from 6.3 to 32.7 m. The stand density varied from 222 to 4360 trees/ha. The accuracy assessment for uniform height−diameter curves was based on the analysis of single tree absolute error distributions. Synthetic indicators of goodness−of−fit, such as: average and standard errors, coefficients of variation and determination were calculated based on absolute errors. The final evaluation of the compared uniform height−diameter models results from the structure of the goodness−of−fit measures that was observed within all analyzed stands and within age classes of 20 years. The efficiency of uniform height−diameter models was also compared with stand height−diameter curve, which was developed based on the Näslund function. General height−diameter models overestimated height in alder stands on average from 0.26 (1.67) to 0.19 m (1.39%), based on skwB and skwO models, respectively. Bias depended on the age of stand and decreases from almost 3% in I age class to nearly 0.5% in IV and V age class. For both analyzed models, a positive systematic error was observed for the standardized breast height diameter. Bias in estimating the height of single stand depended on the accuracy of stand height estimations. In case of estimation based on the measurements of three trees height, bias in single stand can range from –13% to +14%. Due to the range and nature of observed systematic errors, uniform height curves should be applied to groups of stands that have different age and breast height diameter structure, as it allows for partial reduction of the error.
- Źródło:
-
Sylwan; 2016, 160, 08; 635-646
0039-7660 - Pojawia się w:
- Sylwan
- Dostawca treści:
- Biblioteka Nauki
Artykuł