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The assemblages of Coleoptera have been examined in the managed and reserved mature pine forests of Lithuania since 1997. Beetles have been sampled from the forest litter using sieves. The present study is based on the data of 20 litter samples (10 samples per each stand) taken in the period from October 2013 to February 2014. Each sample was compiled of 5 smaller ones taking all litter (up to mineral layer of the soil) from 0.04 m2 plot. During the study a total 450 adults representing 69 species of beetles was discovered. Both the average number of species and the number of individuals were found to be higher in the samples taken in reserved forest and made 10.7±1.4 and 27.2±4.9, whereas in managed forest they made 9.7±1.1 and 17.8±3.4, but the differences were not statistically significant. The proportions of phytophagous, mecetobionts and saprophagous were also bigger in reserved forest: 9.5±2.0, 7.8±2.2, 3.1±1.0 than those in the managed forest, where these groups consisted of 8.0±1.8, 4.9±1.7 and 2.8±1.6 percent of the total number of individuals in the sample, respectively. The opposite proportions were detected for zoophages, which were more ambiguous in the managed forest and were by 76.0±2.5 higher than those in the reserved forest 72.8±3.2. These differences were not statistically significant. A non−metric multidimensional scale (NMDS) using Bray−Curtis similarity matrix indicated low differences of the Coleoptera assemblages between investigated sites (final stress=0.22). The analysis using RDA showed some differences between Coleoptera assemblages inhabiting reserved forest (R) and managed forest (D), which were correlated with proportions of humified mortmass (+0.88) and biomass of moss (–0.63 and –0.71). The dissimilarity index calculated using the algorithm SIMPER, was quite high (71%), but the obtained results showed a relatively low diversity of beetle assemblages in both forests. It means that the process of transformation of the managed forest into reserve is very slow, most likely due to the fact that restoration of the microhabitats is particularly slow. Low differentiation of Coleoptera assemblages dwelling in litter is associated with low dispersal power of most coleopteran species. Thus, the establishment of new reserves in old growth pine forests can not stimulate fast increase of specific beetle diversity mainly because the regenerative processes of microhabitats seem to be extremely slow. The specific diversity of beetle assemblages was slightly higher in the reserved forests, but it was not confirmed statistically. In comparison with the managed old growth pine forest the period of fifteen years of reservation of old growth pine forest has only a very low effect on specific diversity and ecological specialization of the beetles.
Spontaneous regeneration in the hurricane−disturbed stand in the Pisz Forest District (N Poland) was registered in the years 2007−2008 and 2011−2012. Breast height diameter and crown size were measured on 10×10 m plots. The analysis also included the soil respiration rate, the decomposition rate of organic matter, soil pH, leaf area index (LAI), content of Mg, Ca, C, N and P in soil, and vegetation coverage of the forest floor. The natural regeneration was dominated by birch, followed by pine, which recolonized the disturbed stand in smaller extend, possibly because of the thick cover of organic material hindering germination and making it difficult for pine sprouts to reach the mineral soil. Spontaneous regeneration of the stand was most severely inhibited by Deschampsia flexuosa, whose growth over the entire surface was linked to the capture of excess released nitrogen resulting from the decomposition of organic matter. Mosses and lingonberry did not delay the spontaneous appearance of seedlings. The development of the natural regeneration suggests the possibility that an uneven−aged stand will emerge.
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