IPCC (2014) defines vulnerability as “the propensity or predisposition to be adversely affected”, it further states that vulnerability “encompasses a variety of concepts and el-ements including sensitivity or susceptibility to harm and lack of capacity to cope and adapt”. Knowledge on vulnerability of forests, national forest management systems, for-est-dependent people and related branches of the economy is key for identifying risks and adequate adaptation options (FAO and CIFOR 2019). The huge area and diversity of Russia’s forests reflects a similar diversity of current and predicted climates as well as of related stress factors and risks. The level of vulnerability substantially depends on the intensity of climate change exposure: while a future climate in line with the Paris Agreement (RCP2.6) may on average have favorable effects for Russian forests with only limited changes in the current forest sector vulnerability, scenarios with limited emis-sion reductions (like RCP 6.0 and RCP8.5) project critical forest growth conditions that threaten in vast regions the survival of major forest species (Tchebakova et al., 2009;
Gauthier et al., 2014, 2015).
The vulnerability of boreal forest ecosystems depends on their adaptive capacity, which is supposed to be relatively high because of their huge genetic populations, high fecun-dity, high levels of genetic and ecosystem diversity, as well as historically formed mech-anisms of tolerance to natural disturbances (Aitken et al., 2008). On the other hand, boreal forests evolutionary formed under cold climates and are sensitive to warming, because of the nature of their landscapes and soils with a wide distribution of wetlands and permafrost. The high frequency and projected increase in disturbance severity like fire and insect outbreaks are further crucial vulnerability drivers affecting the forest sec-tor under climate change.
The risks for forests will be the highest in hotspot regions exposed to major direct (high summer temperature, water stress) and indirect (accompanied disturbances) driv-ers. The highest risks for forest survival are expected at the transition zones between forests and treeless areas at the northern and particularly southern limits of the forest zone. Forests in the southern taiga zone and at mid-latitude forest steppe ecotones are particularly vulnerable due to water stress (Tchebakova et al., 2009), with particular risks for biodiversity, wild fauna and livelihood of the local population (e.g. Tchebakova et al., 2009; Kharuk et al., 2017a). Shifting species distribution ranges (see Chapters 4.1 and 4.2) substantially enhance vulnerability of forests due to disparity between the rate of natural tree migration in the high latitudes – less than 100 m per year (Aitken et al., 2008), compared with the northward shift of climatic conditions that is 10 to 50 times faster (Thuiller 2007). Taking into account the natural barriers in Northern Asia (rivers, high latitudinal mountain ridges), real migration rates may be even slower. Permafrost territories above 500 mill. ha Russian forests represent a vast hotspot region, which
4.3
w h at s c i e n c e c a n t e l l u s
contain a huge amount of carbon. Thawing permafrost combined with increased arid-ity of the hydrological regime on hundred million hectares may trigger drastically in-creased fire risks and release enormous amounts of greenhouse gases, representing a
“tipping point” in the Earth system (Lenton et al., 2008).
Vulnerability of forests also affects people. Russia has about 260 000 people belong-ing to 39 small indigenous nations, many of whom directly depend on forests. Also, so-cial and economic changes in Russia after the 1990s have led to the slow death of sever-al thousands of taiga villages located around former industrisever-al facilities. The remaining population in these settlements is almost completely depending on forests. Moreover, large parts of the regional population in forested regions is vulnerable to extreme weath-er events and accompanying catastrophic disturbances because of inadequate forest fire protection and weak capacity and preparedness in disturbance risk management. This may lead to critical health impacts, premature deaths of thousands of people, and large economic losses (Bastos et al., 2014; Shvidenko et al., 2020).
Vulnerability of Russia’s forests to disturbances represents the most dangerous cur-rent and particularly future risk. Regional disturbance regimes are projected to intensi-fy, as extent, frequency and severity of wildfires and outbreaks of dangerous insects and pathogens substantially increase. It is very likely that the vulnerability of mid-latitude forests of Eurasia will be critically magnified by diverse dangerous biotic agents includ-ing alien insects and pathogens. While local reasons of observed resilience decline and death of forests differ (e.g. periods with severe drought, invasions of insects and patho-gens, changes of the hydrological regime, planting forests in inappropriate conditions, lack of satisfactory forest management), there is increasing evidence that all these pro-cesses have been directly or indirectly affected by climatic and environmental changes (Shvidenko et al., 2017). Consequently, a tipping point of boreal forests may be reached under lower levels of warming than earlier anticipated (Lenton et al., 2019). Recent ex-periences question the ability of current national forest management systems includ-ing legislation and forest management manuals, institutional structure, and forest pro-tection capacities to meet the challenges of the fast-changing world.
Vulnerable forests lead to a high vulnerability of the Russian forest industry. The most valuable tree species for the Russian forest industry are pine and spruce, which are also very vulnerable to climate change. Catastrophic fires and insect outbreaks have in recent decades completely destroyed highly productive forests on hundreds of thou-sands of hectares which were then regenerated by early successional species of lower economic value. A crucial problem for the Russian forest sector is the poor transport infrastructure, especially the lack of all-season roads (Goltsev at al., 2011). In most re-gions with abundant forest resources, logging companies can access remote forest areas only during wintertime. The logging and transport of wood heavily depend on weather conditions. During the warm Decembers in 2006, 2007, 2011, 2019 and 2020, loggers had substantial difficulties in wood removal (Prokopyev et al., 2018; Lebedeva, 2020).
Russian forests and climate change
(2012) concluded that the sector is in a critical state, and real management does not satisfy requirements of sustainable, risk resilient forest management. This study analysed three scenarios of Russian forest sector development until 2030 and found that the Russian forest sector requires radical reconstruction, otherwise it will negatively impact its sus-tainable functioning and supply of wood to national economy. Without that the Russian forest management will not be able to meet challenges of dramatic climate change.
Despite numerous studies on impacts of global change in Russian forests, many ecological processes and tendencies are poorly understood, and uncertainty of climatic, social and economic projections remains high. These uncertainties create special diffi-culties to the development of future strategies of co-evolution of human and forests in high latitudes.