Tree diversity patterns along the latitudinal gradient in the northwestern Russia

Abstract

Background: One of the key forest characteristics is the biodiversity, particularly the diversity of trees which are forest ecosystem engineers. Nowadays the most worldwide common approach for assessment of forest conditions and dynamics is based on the systematic monitoring, performed at a set of regularly structured plots. To fulfill the existing gap in this sort of knowledge on the Russian forests, an extensive study of tree species diversity on a regular network was conducted in north-west of Russia. Methods: The study used the ICP Forests monitoring network that spans over 1700 km along the western Russian border from forest-tundra in the north to broadleaved-coniferous forests in the south. Tree data were collected at 710 sites that were assigned along a regular grid. We performed series of statistical analyses of the tree species distribution and diversity in relation to environmental and anthropogenic factors. Results: According to the Maxent species distribution modelling results only Pinus sylvestris, Betula sp. and Picea abies have the potential to grow throughout the study area. The locally maximum tree species diversity varies along the latitudinal gradient from 1 to 3 species in the north to 5-7 species in the south. Monocultural stands are relatively abundant across the study area, being especially common in the south taiga. The prevailing part of the monocultural stands is represented by Scots pine (72%). The age distribution of dominant trees has a clear connection with the intensity of forest use. We found that recent wildfire events had only little effect on tree diversity in the study area. Conclusions: We demonstrated that ICP Forests monitoring network enables to successfully establish the main qualitative and quantitative relations of the spatial variation of tree species diversity to climatic, landscape, soil and anthropogenic factors. Analysis of the influence of these factors on tree species distribution allowed us to conclude that with the continuing trend of reducing the frequency and intensity of fires, Norway spruce will further replace Scots pine and Betula sp. in the north-western Russia. Extending the monitoring network, especially adding the time-series context, could provide novel appealing opportunities for forest dynamics projection and sustainable management.

Linking Forest Vegetation and Soil Carbon Stock in Northwestern Russia

“…Plots are clusters with four circular sample subplots, on which at least six trees of the dominant species grow. The circular subplots are located at a distance of 25 m and are oriented to the cardinal points from the plot centre (central tree) [17,18].…”

Dynamics of the Taxation Characteristics of Forest Stands in the North-West of Russia

“…A well-functioning forest ecosystem is characterized by a sufficient diversity of tree species. The composition of thereof depends on climatic, biotic and other conditions [15].…”

Functional Role of Extrafloral Nectar in Boreal Forest Ecosystems under Climate Change

“…Boreal forests (taiga) cover about 33% of the world's total forest area, representing the largest terrestrial biome on Earth [40]. They are a globally important sink and storage pool of carbon [41] and are mostly dominated by coniferous trees [42]. Furthermore, the largest remaining unfragmented and natural landscape patches without human impact can be found in Russian and Canadian boreal forests [43].…”

“…Furthermore, the largest remaining unfragmented and natural landscape patches without human impact can be found in Russian and Canadian boreal forests [43]. In addition to conifers, deciduous trees such as Betula pendula Roth, B. pubescens Ehrh., Populus tremula L., Alnus incana (L.) Moench, A. glutinosa (L.) Gaertn., Sorbus aucuparia L., and Salix caprea L. can be dominant tree species in mixed stands in Scandinavian and Finnish taiga forests [42,44]. With the warming climate, there is a shift in the boreal forest biome towards the arctic [45], and the proportion of deciduous trees in boreal ecosystems will increase due to a northward shift of many thermophilic tree species [46][47][48][49][50].…”