Nemoral Forests

In this article, the authors propose a predictive landscape-ecological analysis of the forest cover of the Volga basin, which highlights the problem of adsorption of greenhouse gases, which is included in the list of tasks set the Paris Climate Change Agreement (2015). As a result of the study, the authors established the adsorption potential of indigenous and derived boreal and nemoral forests, assessed their ability to mitigate climate change, including reducing anthropogenic warming. A quantitative assessment was also made of the loss of these ecological resources by the forests of the Volga basin since the beginning of intensive forest and land use in it. We have identified contrasting changes in the ecological resources of boreal and nemoral forests during their structural transformation in the course of global warming. We show that the process of thermal-arid transformation of forest ecosystems leads to a general decrease in the positive carbon balance in most groups of forest formations. The verification of the predicted calculations of the carbon balance, carried out by remote and ground measurements in the boreal forests of Central Canada in the first decade of modern warming, gave positive results.

Ecological Resources of Boreal and Nemoral Forests in Regulation of the Carbon Cycle and Mitigation of Present Global Warming

A set of medium-scale historical maps was used to reconstruct changes in spatial patterns of forest area during the last 220 years in an agricultural matrix of northeastern Europe (Zemgale region, Latvia). Changes in total forest area by soils were determined, as well as the time period of continuous forest cover. Proportion of protected area for each soil trophic group was also calculated. Patterns of recent forest development differed between soil trophic groups. Afforestation occurred mainly on wet and poor soils in the 19th and 20th centuries, while the proportion of woodland area on fertile soils typical for nemoral forests was fairly stable. Only 1% of the fertile soil area has been covered by continuous forest for more than 220 years, and only 11% of them are protected. Nemoral deciduous forests cover only 15% of their potential natural vegetation area of forested eutrophic soils. Therefore, in regard to habitat protection that is representative of natural distribution of ecosystems, priority in conservation should be given to forests on fertile soils.

Harvesting naturally dynamic forests causes losses of habitat quality and functional connectivity. Focusing on Sweden as a case study of high-yield rotation forestry, we provide analyses supporting spatial prioritisation of protection, management and restoration of representative functional forest habitat networks. Habitat suitability index modelling of focal birdspecies was used to analyse how forest naturalness, habitat patch size and functional connectivity affect representative forest habitat networks in Sweden's five ecoregions. Habitat modelling for the least demanding bird species showed that of the mountain ecoregion 57-77% was functional, but in the other three boreal ecoregions only 8-9% were functional. For nemoral forests, the proportions of functional habitat networks were < 3%. More demanding species have even less functional habitat. We highlight the importance of the mountain ecoregion for forest biodiversity conservation, and the urgent need for landscape planning of protection, conservation management and nature restoration in Sweden.