Accurate prediction of ice disturbance in European deciduous forests with generalized linear models: a comparison of field-based and airborne-based approaches     

Réka Aszalós  Imelda Somodi  Kata Kenderes  János Ruff  Bálint Czúcz  Tibor Standovár 《European Journal of Forest Research》2012,131(6):1905-1915

We analyzed an ice disturbance event of deciduous forests in Hungary by Generalized Linear Models (GLM). Two statistical models were generated: the first model was based on a disturbance map created from a series of aerial photographs, and the second model was based on a map created by half-year-long intensive field work. The second map was considered as the reference map of ice disturbance. Our hypothesis was that the predictive power of the field-based statistical model would be significantly higher than that of the aerial photo-based model on the reference map. Elevation, slope, aspect, mixture ratio of beech, height of the dominant tree species and their interactions were used in the two (aerial photo- and field-based) GLMs as explanatory variables. The accuracy of the models was measured by the AUC (Area under the ROC curve) values. Sensitive area maps of ice disturbance were generated by both models. Our hypothesis was definitely rejected. Both models performed high predictive accuracy (median AUC > 0.9) with no significant difference in the prediction capacity regarding the reference ice disturbance pattern. Our study demonstrates that ice damage can effectively be predicted if remote sensing interpretation is coupled with GLM as predictive model.  相似文献   

Thirty years of gap dynamics in a central european beech forest reserve     

Kenderes  Kata; Mihok  Barbara; Standovar  Tibor 《Forestry》2008,81(1):111-123

Investigation of gap characteristics and tree regeneration patternsis central for our understanding of forest dynamics. By integratingaerial photograph analyses and ground surveys, we provide astudy of long-term canopy gap dynamics and tree regenerationpatterns in a Hungarian beech forest reserve. We found (1) thatin spite of the overall increase of gap area during the investigated30-years (from 2.5 to 7.7 per cent), total gap area and averagegap size (40–93 m²) were remarkably similar to those foundin other temperate and tropical forests, (2) if the fate ofindividual gaps was followed, two to three times more intensivecanopy dynamics (gap creation, closure and expansion) couldbe recognized than simple change of gap area indicated, and(3) average seedling density was considered to be sufficientfor natural regeneration. However, it was apparent that recentincreased deer browsing had prevented establishment of youngertrees of 1–2 m in height, as taller saplings were recordedonly in old gaps. Our results not only provide useful informationon forest dynamics but can also contribute to understandingthe potential roles that small forest reserves can play in providingessential reference data for nature-based forest managementof this forest type.  相似文献