Coleoptera assemblages of pine forests depends on the distance to the source of nitrogen pollution

The paper analyzed the changes of beetle assemblages in the litter layer of eutrophic pine forests in the zone polluted by a nitrogen fertilizer plant Joint Stock Company “Achema” (Lithuania). We hypothesized that abundance, diversity and life traits of beetle assemblages depend on the distance from the pollution source. The samples of the litter layer were taken from pine stands at the distances of 3, 5, 10 and 20 km from the plant. The PCA and GLM analyses were used to reduce the number of variables to the main environmental gradient and assess the influence of environmental factors on beetle abundance, number of species, and life traits. The dependence of species number, abundance and the presence of forest and dendrophagous species on the distance from the plant was detected. A significant impact of organic carbon content, nitrogen emission and moss cover on other life traits of beetles was disclosed. The abundance of moss fraction in the litter layer was positively correlated with increasing distance from the plant. The ability to tolerate polluted sites by three species: Atheta fungi, Micrambe abietis and Brassicogethes aeneus, and intolerance of pollution by eight species: Bryaxis puncticollis, Quedius limbatus, Cyphon pubescens, Cephenium majus, Cyphon padi, Cyphon variabilis, Gabrius appendiculatus and Philonthus cognatus, were detected by IndVal analysis. The distribution of litter species was affected by the distance from the plant and by the richness of moss cover

Coleoptera assemblages inhabiting managed and preserved pine forests - the effect of fifteen years of reserve conservation

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

Effect of larch admixture on forest litter beetle (Coleoptera) communities diversity and number of carabid individuals in mixed coniferous habitats of Lithuania

During winter time, beetle individuals were collected from soil samples taken from a Scots pine culture, an old−growth Scots pine forest, and a European larch culture and old−growth. The following research questions were put forward: (1) Does an admixture of larch in the forest stand contribute to increase in species diversity as well as the numbers of beetle individuals hibernating in the forest litter? (2) Does an admixture of larch in the forest stand result in an increased proportion of beetle species – potentially pests for the forest trees, in the carabid communities? We analyzed data with use PCA, Ward method. The first question should be answered positively. The second question should be answered negatively. The analyses of beetle fauna overwintering in the forest litter as carried out in this paper confirmed the purposefulness of larch introduction as an admixture in pine stands in Lithuania

Early effect of clear-cuts and their tilling on assemblages of epigeic rove beetles (Coloeoptera, Staphylinidae) in Pinus sylvetris stands

The studies were conducted on three plots, established in 100−130 year old Scots pine (Pinus sylvestris L.) stands (type: Pinetum vaccinio−mirtyllosum) situated in the southern and central parts of Lithuania (Kaunas and Vare˙na districts). Their canopy closure was from 0.6 to 0.8. The study areas comprised of a mature stand (control) and clear−cut felled in spring 2016 and tilled after 5 months. Altogether 30 litter samples (five per stand) were taken from randomly chosen locations twice: the first sampling took place one month after cutting (in May) and the other after five months (in October). In total, 921 adults and larvae representing 49 species of rove beetles (Coleoptera: Staphylinidae) were collected. The higher number of individuals was harvested in control stands (fig. 1a, tab. 1). The collected individuals were significantly more abundant during the second sampling in all studied stands (fig. 1b, tab. 1). In the same way the higher number of species was detected in control stands, but significant differences were observed only during the first sampling. Amount of forest species differed insignificantly between control stands and clear−cuts, while the rate of zoophagous species was significantly higher in control stands (fig. 2a, tab. 1). The number of mixophagous species was significantly higher in clear−cuts during the second sampling (fig. 2b−c, tab. 1). Both the felling and the tilling had a distinct impact on transformation of rove beetles assemblages in clear−cuts comparing to the mature stands (fig. 3). Ischnosoma splendidum, Othius subuliformis, Stenichnus scutellaris, Trimium brevicorne, Xantholinus tricolor, Philonthus cignatus and Sepedophilus sp. were revealed as associated with mature pine stands sites, while only Acrotona parens and Amischa analis were connected with clear−cuts (tab. 2). We propose to use these two species as indicators of strong transformation of rove beetles assemblages due to clearcutting and management. The results of the study proved that negative impact of clearcutting on number of individuals and number of forest species in rove beetles assemblages is distinct even in short period after cutting as well as that transformation of rove beetles assemblages increase after cutting of stand, especially after tilling