- Institutionen för skoglig resurshushållning, Sveriges lantbruksuniversitet
Ramezani, Habib; Nazariani, Nastaran
If available forest inventory techniques or measurement instruments are not satisfying or appropriate for monitoring a particulare forest, options include developing a new inventory technique and/or modifying an available instrument. In this study, we present a new application of horizontal line sampling (HLS) in combination with a crown relascope as a potential alternative to line intersect sampling (LIS) to monitor coppice forests (CF). In CFs, the stem basal area relascope is not applicable, since trees often lack distinct stems and are not visible at breast height. Our study was conducted in an open oak-dominated CF in western Iran and we focussed on two forest attributes: above-ground biomass (AGB) and the total number of trees (N). We assessed the field performance of HLS and LIS in CFs and evaluate various line transect lengths and crown relascope angles. Our results indicate that longer line transects (80 m) produce smaller relative sampling errors compared to shorter ones (20 m) and smaller relascope angles (36.8 degrees) are more precise than larger ones (67.4 degrees). In terms of cost-efficiency, HLS is superior or equivalent to LIS in some cases. While HLS and LIS gave different estimates of AGB and N, the difference was not statistically significant at the 95% level. Both relascope angle and line transect length impact the efficiency of HLS. Our study provides evidence that this technique can be useful for monitoring forest conditions.
cost-efficient design; forest inventory; open sparse oak forest; Quercus brantii; Zagros forest
Austrian journal of forest science
2023, Volym: 140, nummer: 2, sidor: 77-98
Utgivare: OSTERREICHISCHER AGRARVERLAG