Detecting Hornbeam Trees Phenological Characteristics of Mountain Forest

Abstract

Problem statement: Phenology is the study of the seasonal occurrence of developmental or life cycle events, such as bud break, flowering, or autumn leaf drop. The proposed study attempted to quantify changes in Carpinus betulus L. phenology of deciduous broad leaf forest between the years 2003-2006. Approach: Phenological studies were fulfilled during four years as from January 2003-December 2006 by using ground observations and IRS1C/1D -LISS-IIΙ data. This study was performed on different altitudes and different aspects. The six sample plots were selected in study area. The statistical analysis showed that there were significant differences between the phonological characteristics in respect to the different site physiographical characteristics. Results: Leaf appearance at this type begins at the first of the third week of April Mostly and continues up to the first week of May. Leaves in this species begin to fall as from the beginning of the fourth week of November and will continue up to the end of first week of December. Furthermore there were significant negative correlation between average precipitation and average air temperature and there of the phonological characteristics. The correlation between average air temperature and leaf mature and fall date was significantly negative. The present study was specified that among the factors of study case, altitude from sea level had in priority and delay of appearance of phenological event has more obvious role out of the other factors. And also, the results show that over the study period, the growing season duration has lengthened by 1.8 days year^-1 in study region. The green-up of vegetation has advanced in the spring by 1.2 days year^-1 and the dormancy delayed in autumn by 0.6 days year^-1. The altitude from sea level had in priority and delay of appearance of phenological event has more obvious role out of the other factors. Conclusion: The growing season duration of Iran’s deciduous broad leaf forest was significantly lengthened, primarily through an earlier green-up and a later dormancy during the period of 2003-2006.