Sensitivity of Russian forest timber harvest and carbon storage to temperature increase

David A. Lutz 1 2 Herman H. Shugart 1 Mark A. White 0 0 McIntire School of Commerce, Rouss & Robertson Halls , East Lawn , University of Virginia , PO Box 400173, Charlottesville, VA 22904-4123 , USA 1 Department of Environmental Sciences, University of Virginia , 376 Clark Hall, 291 McCormick Road, PO Box 400123, Charlottesville, VA 22904-4123 , USA 2 Environmental Studies Program, Dartmouth College , 6182 Steele Hall, Room 113, Hanover, NH 03755 , USA Russia is a leading exporter of industrial round wood and supplies many countries with a large share of their wood fibre. However, warming temperatures are likely to have an impact on the productivity of Russian forest stands and affect their production capacity and management. The forest gap model FAREAST was used to derive biological growth parameters of several forest types; these data were then used within an economic model to discern the response from both a timber harvest and carbon sequestration perspective. An incremental warming of 28C resulted in an increase in the timber harvest for most forest types. A 48C increase, however, caused nearly all projects to yield less timber and sequester less carbon than under current conditions. Only stands in northwestern Russia stocked with Pinus sylvestris, a fast growing heat-tolerant species, continuously increased timber harvest and carbon sequestration in parallel with extreme temperature changes; however, stands with greater species diversity were less sensitive to increased temperatures. Russian forest carbon sequestration, a process mentioned as a method to mitigate climate change, may become less effective by the same process it is hoped to assuage. - Russia, home to nearly one-quarter of the planets forests,1 is the worlds largest exporter of industrial round wood.2 Russian forestry is an important part of the countrys economy, contributing over $7.7 billion in 2009 (FAO, 2006)3 and a major employer, employing 849 000 Russians in 2006 (FAO, 2006). Raw timber products from Russia are critical for countries which import a majority of their wood resources, such as China and many countries within Europe. Exports of timber to China, totalling $1.32 billion in 2002,4 have almost doubled in recent years, reaching $2.5 billion in 2009.2 Considering that nearly 30 per cent of Russian logging is estimated to be illegal,5 these financial estimates are likely to be conservative and may underestimate the full economic importance of the Russian forestry industry. While Russian forestry is a major industry with far-reaching impacts, its harvest only makes up 3 per cent of the worlds total.2 This is despite the fact that Russia contains 20 per cent of global wood resources.6 In the past decade, exports have consistently increased and indications that the forest sector will continue to grow are numerous.7 However, climate change and warming temperatures are an important source of uncertainty for Russian forest managers. Temperatures have been rising in much of the area that contains Russian forests. Dendrochronological records indicate that temperatures in northern Siberia are currently the warmest in over 1000 years,8 while an analysis of global weather station data suggests that Russia has been experiencing warmer temperatures in the past half-century.9 Data compiled from 44 regional weather stations throughout Siberia from a baseline period of 1960 1990 compared with the period of 1991 2010 indicate a 2 38C warming during winter in northern Siberia and a 1 28C increase during summer in Southern Siberia.10 Both the Arctic climate impact assessment and the Intergovernmental Panel on Climate Change (IPCC)s findings imply that the circumboreal region, an area that contains much of Russias forests, will experience temperatures nearly 40 per cent above the global mean in the coming decades.11 These climate variations are expected to seriously impact nearby forested ecosystems. Modelling exercises in Russian forests have shown that underlying forest composition will change in response to projected changes in temperature.12 15 In particular, cold-adapted species such as Siberian larch (Larix sibirica) may be replaced by species which can withstand warmer temperatures, like Siberian pine (Pinus sibirica).12 In Eastern Eurasia, deciduous trees such as Fraxinus, Ulmus, Quercus and Tilia may extend their range at the expense of coniferous species.14 Analyses of forest plots have detected current transition from Dahurian larch (Larix gmelinii) to evergreen conifers such as spruce, fir and pine in central Siberia over the past three decades.16 To properly adapt to increasing temperatures, forest managers may have to cultivate species that traditionally were not planted or did not exist in the areas that they manage or else look for alternative sources of income from their forests.17 In the case of Russian forestry, managers need to be aware of their stock sensitivity to warming temperatures and understand how it may influence their economic expectations. If climate change provides economic setbacks to traditional timber management, alternative strategies for economic gain may be useful to Russian forest managers. Carbon sequestration platforms that encourage forestry plantations as a methodology to mitigate greenhouse gas levels in the atmosphere may provide such an additional strategy.18 For example, the Kyoto Protocols clean development mechanism (CDM) includes afforestation and reforestation as financial opportunities for forestry managers as a method of carbon sequestration. Many studies have highlighted this potential19 21 yet very few forestry CDM projects exist22 and none exist within Russia. Estimates suggest that nearly 50 80 million ha of currently unforested land within Russia could be reforested, yielding a 2.5 t C ha21 year21 carbon sink.23 Current logging practices in these areas allow for regeneration rates of significant length, typically 120 140 years as dictated by the biology of the stand and not the economic yield.24 By managing their forests to maximize carbon sequestration and selling credits on regulated and/or unregulated markets, Russian forest managers may have another option for the direction of their enterprises. Detailed studies regarding forest carbon sequestration projects within Russia are not present in the scientific literature; however, total carbon pool estimates suggest that Russia and its forests have been a net sink from 2000 to 200725 and therefore particular areas of Russian forests may be suitable candidate sites. Detailed simulations of Russian forest responses to rising temperatures are useful for addressing uncertainties related to forest sensitivity. Traditionally, computational models have been the primary tool used to answer these types of questions. However, such models generally stem from either the economic Pine West Pine Central Pine East Spruce Fir West Spruce Fir Central Spruce Fir East 57.78 Deciduous Mix West 55.58 (...truncated)