Effects of radial growth of swamp pine forests from the perspective of the phytosocial paradigm
S. P. EFREMOV1, T. T. EFREMOVA1, A. V. PIMENOV1, M. V. SEDEL′NIKOV2
1Krasnoyarsk Science Centre of the Siberian Branch of Russian Academy of Science, Sukachev Institute of Forest, Siberian Branch of the Russian Academy of Sciences, Krasnoyarsk, Russia
2Siberian Federal University, Humanitarian Institute, Krasnoyarsk, Russia
Keywords: habitat clusters, tree-ring width, chain radial growth, trend equations, russian phytosociology
Abstract
Regularities of radial growth of pine (Pinus sylvestris L.) were studied within the southern taiga subzone of Western Siberia. The objects of the study were pine forests: uplands on sandy podzols and swamps under different conditions of water-mineral nutrition and pyrogenic influence. Using the methods of multivariate statistical analysis (cluster and discriminant analysis) based on the data of cyclic fluctuations in radial growth (increase, decrease or duplication of the subsequent one relative to the previous one), 4 clusters were identified. Swamp pine forests - eutrophic, oligo-mesotrophic, oligotrophic and upland pine forest. The final result of correctly classified objects is 100 %. The average width of growth rings in dry land conditions is 1.05 mm. In eutrophic swamp pine forests - 0.81 mm, oligo-mesotrophic - 0.57, oligotrophic - 0.39 mm. The main trend in the change in the width of tree rings over time (trend) is determined by a second-order parabola (p-level < 0.001). The signs and highly significant coefficients of the regression equations are postulated. In oligotrophic pine forests, the width of the rings increased annually on average by 0.80 mm with an annual average slowdown of 0.004 mm - an extreme of 190 years (inflection point). In oligo-mesotrophic ones - at 0.95 and 0.002 mm - the extremum is 340 years, in upland ones - at 4.27 and 0.068 mm - the extremum is 62 years. In eutrophic pine forests, according to the linear trend, the increase in the width of annual rings for 1 year averaged 0.715 mm. The relative frequencies of cyclic fluctuations in the increase and decrease of tree rings are characterized by equivalent ratios of their occurrence: 45-48 % in eutrophic and upland pine forests, 40-41 % in oligo-mesotrophic and oligotrophic ones. These equally possible episodes of recurrence can be considered one of the mechanisms for the formation of society through the probabilistic good neighborly relationships of trees in the interests of the whole. The frequency of occurrence of duplicate variants in eutrophic and upland pine forests is 7-9 %, increasing to 18-20 % in oligotophic and oligo-mesotrophic ones: the more severe the conditions, the higher the concordant onset.
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