tailieunhanh - Báo cáo lâm nghiệp: "Results of a phenological study of the tree layer of a mixed stand in the region of the Drahanská vrchovina Upland"

Tuyển tập những bài báo cáo nghiên cứu khoa học hay nhất được đăng trên tạp chí JOURNAL OF FOREST SCIENCE đề tài: Results of a phenological study of the tree layer of a mixed stand in the region of the Drahanská vrchovina Upland. | JOURNAL OF FOREST SCIENCE 54 2008 7 294-305 Results of a phenological study of the tree layer of a mixed stand in the region of the Drahanská vrchovina Upland L. Merklová E. Bednárová Faculty of Forestry and Wood Technology Mendel University of Agriculture and Forestry in Brno Brno Czech Republic ABSTRACT The paper presents the results of phenological studies of Norway spruce Picea abies L. Karst. European beech Fagus sylvatica L. and European larch Larix decidua Mill. in a mixed stand in 2004 to 2007. The results show different onset and duration of phenological stages in the particular years. This broad range was important in spring phenological stages. High correlations were determined between the mean air temperature and the start of phenological stages in monitored species. The onset and duration of autumn phenological stages are affected not only by air temperature but also by air humidity. The annual variability in the onset and course of phenological stages in forest species showed that except genetic factors external conditions particularly meteorological factors affecting their onset and duration were also important. Relationships between the onset of phenological stages and changes in meteorological parameters were expressed by the sum of effective air temperatures exceeding 0 and 5 C. To evaluate the relationships by means of the sum of effective temperatures 5 C the stage of budbreak was most important in all studied species. Keywords phenology effective temperature vegetation period climatic change Phenological studies make it possible to understand regularities in the course of life manifestations of plants depending on external conditions of the environment. Thus they are a valuable source of information on the onset and duration of growing seasons in various climatic regions. Phenology serves to monitor the time course of growth and phenologi-cal stages of plants in the given region. In addition to genetic factors also external conditions .