0151-B1

Carbon Balance in the Russian Forests

Boris N. Moiseev and Andrei N. Filipchuk^[1]

Abstract

In the report the method used to estimate carbon balance is based on the national data of the net annual increment (NAI) of growing stock and conversion factors (ratios), taking into account not only the increment of living phytomass but also the net increment of detritum (mortmass), the accumulation of which is typical for boreal forests.

In 2000, on the forest area of Russia (including open stands, sparse forests, cutovers, burns, forest swamps) the carbon pool, with the exception of soil organic matter and peats was equal to 52,000 Mt C, including 34,000 Mt C in living phytomass and 18,000 Mt C in detritum. On average throughout the country the detritum pool amounts to one third of the total phytomass pool.

The annual carbon net ecosystem production - NEP (C) in Russian forests amounts to approximately 600 Mt C/year, including the net increment of detritum at ~200 Mt C/year. According to preliminary estimates, in 2010 the NEP(C) will have increased to 660 Mt C/year.

The summarized emission (losses) of C-CO2 connected with cutting, forest fires, forest pests and diseases amounts to more than 100 Mt C/year. Thus the carbon balance in forest ecosystems of Russia is positive and equal to 500 Mt C/year. Industrial emissions of C-CO2 have approximately the same value in our country.

It is possible to achieve an essential increase of C-CO2 sequestration from the atmosphere (to 45 Mt C/year) only through a complex of forestry measures aimed at forest fire control, protection from forest pests and diseases, utilization of dry trees and wood refuse.

Introduction

In 1994 the Government of Russia signed the United Nations Framework Convention on Climate Change (UNFCCC). In this connection the implementation of the national policy and taking respective measures to mitigate anthropogenic climate change through the reduction of industrial emissions and increase of greenhouse gases’ sinks (assimilation by vegetation) is an important commitment of the Russian Federation. The national measures should be carried out on condition that anthropogenic emissions of CO2 and other greenhouse gases should not exceed the basis level of 1990. This is the requirement of the Kyoto Protocol of the UNFCCC signed by Russia in 1997.

A number of countries have signed the Protocol but it has not entered into force yet (the Russian Federation has not ratified the Protocol). At present some provision of the Protocol are under discussion and negotiation. The most principle object of these negotiations for Russia is the account of carbon assimilation by forests and its acceptance as an equivalent of the reduction of industrial emissions of CO2. Unfortunately there is no common methodology of such assessment.

The methodology developed by the Intergovernmental Panel on Climate Change (IPCC) for tropical forests does not take into account the peculiarities of boreal forests which are characterized by significant and long-term accumulation of detritum (mortmass). The methodical approach of FAO proposed by J.Liski & P.Kauppi (Forest Resources, 2000) which is based on the national forest data and adopted conversion factors is the most proved and acceptable method.

On the global scale the Russian forests being the most important link of the planet circulation of carbon dioxid and oxygen serve as one of the main reservoirs of the atmosphere sink of CO2. According to the FAO data the carbon balance in forest of Russia amounts to 430 Mt C/year (estimation on the natinal data in 1993), or 31% of the global net increment (NPP minus respiration) which is equal to ~ 1400 Mt C/year (Forest Resources, 2000,?.156, fig. 3b1). At the same time the share of Russia makes 11% of the summarized industrial emissions of greenhouse gases in the world. At present the emissions in Russia are more than 30% below the level of 1990. According to the data of A.I.Bedritsky (Bedritsky,2001) in 1990 the summarized emission of greenhouse gases on conversion to CO2 was equal to 3039 Mt C/year, in 2000 ~ 2000 Mt C/year (preliminary data).

In this connection first of all it is necessary to solve the problem of the adoption of the common methodology of carbon balance estimation which should be of course scientific proved, easy in realization and finally it should answer to national and global interests. Here below is a description of the methodology and results of the carbon balance estimation in the Russian forests based on the data of the State account of the Forest Fund in 1993 and 1998.

Method

It is known that the annual net ecosystem production (NEP) is equal to the net primary production (NPP) of plants minus heterotrophic respiration (respiration of non-photosyntesizing organisms living in ecosystem, including soil microorganizms and excluding external catastrophic impacts such as fires, cutting, pest outbreaks and other) and minus the leaching of organic carbon with the summarized water sink (run-off). In real measurements on sample plots the NEP is formed from the sum of the net annual increments (NAI) of living and dead phytomass pools (Basilevich, 1993). It can be expressed by the following balance equations:

where NEP = net ecosystem production (gross annual increment of biomass);
NPP = net primary production (including bark, roots, branches, leaves/needles);
R_h = heterotrophic respiration (biotic and abiotic phytomass oxidization);
Leach = leaching of organic carbon with the water run-off;
Fall = tree fall and litter (Fall=R_h+dM; in climax Fall=NPP=R_h);
dPh = net annual increment of living phytomass (in climax it is equal to zero);
dM = net annual increment of mortmass (in climax it is equal to zero).

Practically the direct measurements of NPP, R_h, Leach, Fall for large areas are not impossible. However the approximately estimations of NAI for living and dead phytomass pools - dPh Ë dM are possible not only on sample plots but also for large areas. There are numerous materials on this problem. We used ready materials on the NAI (periodical) of stem wood stock from the national forest database and also conversion factors (ratios) reflecting the NAI of all living and dead phytomass including dry trees, fallen wood and forest litter as a basis of the NEP estimation.

Throughout all forest management unit (about 1 830) the estimation by main tree species and age class were made by the following formula:

where NEP(C) = net ecosystem production of carbon, t C/ha*year;
NAI = net annual increment of growing stock by a certain age class (group), m³/year;
K_phyt = conversion ratio of living phytomass, t C/m³;
K_mort = ratio of dead phytomass stock to living phytomass stock.

The total NAI was estimated through summing up average increments by every tree species and age class/group (successional stage). The division of growing stock to age class diapason determined the NAI of the age class/group of a tree species (Forest Fund of Russia, 1999). The conversion ratios - K_phyt of carbon pool in living phytomass were borrowed from the initial data of Carbon in ecosystems..., 1994.

The K_mort - ratio taking into account the NAI of dead phitomass (excluding humus) were received by every forest zone (subzone) and by tree species on the basis of data published in the work of N.I.Basilevich (Basilevich,1993). They were corrected and completed by a regional growth tables or models (All-Union standards, 1992), which comprise data on the gross annual increment (GAI) per area unit for the different forest site.

The estimation of carbon balance was made at the level of Subjects of the Russian Federation according to the following equation:

where B(C)= ecosystem carbon balance in forests of Subject of the Russian Federation;
NEP(C)= total net ecosystem production of carbon in forest;
Cut = carbon emission of timber harvested by final cutting, thinning and other cuttings;
Burn = carbon emission of timber and forest litter burned during forest fires;
Pest = carbon emission of phytomass in foci of pests and diseases;
Waste = carbon emission by burning (and by oxidization) timber waste and losses in cut places, clearing roads, road sides and logging terminals;
Fuel = carbon emission by burning fuel wood harvested by rural population independently.

The volume of timber harvested by final cutting, thinning, areas of forest fires and foci of pests and diseases were accepted by the data of annual reports of the Ministry of Natural Resources and the former Federal Forest Service of Russia.

Results

According to our estimation in 2000 on the forest area and other wooded lands = 882 mill. ha the carbon pool (excluding soil organic matter and peats) amounted to 52000 Mt C, including 34000 Mt C in living phytomass and 18000 Mt C in dead phytomass (detritum). On average throughout the country the pool of detritum makes about 1/3 of the total phytomass pool, that is typical for boreal forests. In sub-tundra belt of the northern taiga and in the mountain thickets of Dwarf Siberian Pine the stock of detritum is 1,5 times more than the stock of living phytomass. Thus there is a long-term deposit of detritum in boreal forests, which is expressed in the annual increment of dead phytomass stock as a result of slow rate of wood decomposition by microorganizms. Unfortunately the stock of dry trees and fallen wood is not a subject of the State account of the Forest Fund, although such kind of information has been included already in UN-ECE/FAO reports.

According to the data of the State account of the Forest Fund at 01.01.1998 the NAI of growing stock on forest and other wooded lands amounts to 970,4 million m³/year (Forest Fund of Russia, 1999). In 1993 it was equal to 889,4 million m³/year. Such significant enlargement of NAI took place at the expense of a sharp (threefold) reduction of final cutting (the most part of mature stands was not harvested and was included in the NAI) and the specification of growing stock in open forests of the northern taiga. Table 1 provides data of the NAI by forest zones and subzones.

The mature and overmature Larch stands of Siberia contribute significantly into the summarized increment of growing stock - more than 130 million m³/year. By the forest inventory and planning the age of final harvesting is determined by the commercial maturity of forests stands but not by the biological one (the distribution by age class depends on the age of final harvesting). Therefore a large share of stands being far from climax and giving quite satisfactory NAI and also being suitable to growth conditions were designated to the age class (group) of mature and overmature stands.

The most summarized volume of the NAI is formed in a subzone of the southern taiga although its area is largely less than the area of the northern and southern subzones.

The estimation by formula 2 has showed that the net ecosysten production of carbon - NEP (C) in the Russian forests amounts to 600 Mt C/year (Table 1), including about 200 Mt C/year which is the increment of living phytomass stock compensating a part of tree fall and litter fall. It is numerically equal (in real dimension and estimation) to the net increment of detritum (NEP(C)» GAI(C)). According to our preliminary assessment in 2010 the NEP (C) will amount to approximately 660 Mt C/year.

Table 1. NAI and Net ecosystem production - NEP (-) by forest zones and subzones.

It is interesting to note that the forests of the middle taiga make the most summarized carbon pool apparently at the expense of the greater volume of the deposited detritum in comparison with the same volume in the southern taiga.

Table 1 shows also the average values of integral conversional ratio of the NEP (-) in tC/year to the stem wood stock in m³/year (K_int = K_phyt (1+K_mort)) on lands covered with forest stands in different forest zones and subzones. Some increase of the conversional ratio in forest-steppe zone is connected with the predominance of oak stands on these territories.

The carbon balance in forest ecosystems in 1990 and 2000 was estimated for every Subject of the Russian Federation (Table 2). In 1990 it was equal to +442, in 2000 = +493 Mt C/year. These data agree with the FAO-GFRA 2000 (Forest Resources, 2000).

Table 2. Carbon balance in forest ecosystems of Russia

According to the Ministry of Natural Resources of the Russian Federation the volume of harvested and removed timber of final cutting, thinning and other made in 1990 - 331 million m³, in 2000 -158 million m³. The share of carbon emission as a result of burning wood residue and wood refuse was accepted approximately at the rate of 50-20% of the total summarized carbon volume of the timber harvested by final cutting, intermediate use and other (expert assessment).

By the estimation of carbon emission as a result of fires the share of burned biomass on burned out areas (in 1990 - 974000 ha, in 2000 - 1281000 ha) was set as following: upper and underground fires amounted to 40-60 %, ground fires amounted to 20% of the average carbon stock on these areas (expert assessment).

The losses of living phytomass in foci of pests and diseases (in 1990 - 1828000 ha, in 2000 - 8401000 ha) were set at the rate of 50% of the NEP(C) on this area (expert assessment).

The fuel wood consumption at the rate of 1-2 ϳ or 250 - 500 kg - per 1 person for the rural population of a region (total 41,5 million people) was set for the estimation of carbon losses as a result of burning fuel wood (expert assessment).

The forest areas of the Central and East Siberia, the Far East are the main depositors to the net carbon sink of the country (more than 170 Mt C/year). Along quite productive mature and overmature stands at 184 million ha there are 144 million ha of young and middle-aged stands, which increment provides a high level of the positive balance of - -Œ₂. For instance in 2000 the ecosystem carbon balance of Yakutia made +68 Mt C/year, Khabarovsk region - +31 Mt C/year, Krasnoyarsk region- +27 Mt C/year, Irkutsk region - +44 Mt C/year.

The regions with a negative value of carbon balance in forest ecosystems were discovered by the estimation. Such territories are situated in the arid zone of the European part of Russia where the summarized phytomass losses exceed the NEP (Stavropol region, Republic of Kalmykia, the southeastern parts of Volgograd, Rostov and Astrakhan regions). It is necessary to take measures on the creation of "carbon forests" in these regions probably with the involvement of the financial resources of industrially regions.

About 4 million ha of forest plantations were created in Russia within 11 years (1990-2000). Their average safety does not exceed 50%. The summarized NEP will amount to 1,6 Mt C within 11 years by the average increment of young growth at 0,8 tC/ha*year. It can be seen that the creation of "carbon forests" will not play a remarkable role in the total carbon balance of the country. However in the arid zone where every grown tree represents a great value the creation of forest plantations is necessary since the forest stands in regions with a negative forest balance can disappear not having rational help of people.

Conclusion

Ö The methodology to estimate carbon balance in boreal forests should be based on the national data of the net annual increment (NAI) of growing stock and conversion factors taking into account not only the increment of living phytomass but also the net increment of detritum (mortmass).

Ö In 2000 throughout forest areas of Russia (including open stands, sparse forest, cutovers, burn area, forest swamps) the carbon stock with the exception of soil organic matter and peats amounted to 52000 Mt C, including 34000 Mt C in living phytomass and 18000 Mt C in detritum. On average throughout the country the detritum pool makes about 1/3 of the total phytomass pool that is typical for boreal forests.

Ö The annual long-term carbon deposit - NEP(-) in the Russian forests amounts to about 600 Mt C/year, including ~200 Mt C/year of the net increment of detritum. According to the preliminary estimation in 2010 the NEP (C) will increase to ~660 Mt C/year.

Ö The summarized emission of C-CO2 connected with cutting, fires, forest pests and diseases amounts to more than 100 Mt C/year. Thus the carbon balance in forest ecosystems of Russia is positive and reaches 500 Mt C/year. The industrial emission - -Œ₂ in our country has approximately the same value.

Ö The significant increase of the C-CO2 sequestration from the atmosphere (~45 MtC/yr) can be achieved through a complex of forestry measures directed to forest fire control, protection from forest pests and diseases, utilization of dry trees and wood waste (felling residues). Cutting mature and overmature stands should not be considered as a positive factor since the connected with them oxidization of felling residue and soil erosion enlarge significantly greenhouse gases emission. The young growth and middle-aged stands really provide the greater phytomass increment. But at the same time the increase of CO2 emission takes place as a result of the autotrophic respiration of plants. Besides, the mature and overmature stands of coniferous species in our country are far from climax and made an essential NEP(C) - more than 150 MtC/year.

Bibliography

Basilevich N.I. (1993) Biological productivity of ecosystem in the North Eurasia - M.: Nauka, 1993. - 293 pp. (in Russian).

Bedritsky A.I. (2001) National Interests: to prevent dangerous climate changes - Use and Protection of Natural Resources, ð7. (in Russian).

Forest Fund of Russia (1999). Reference book -M.: ARICFR, 650 pp.(in Russian).

Moiseev B.N., Alferof A.M., Strakhov V.V. (2000). Assessment of carbon stock and increment in the Russian forests//Forestry, N 4, 18-20 pp.(in Russian).

All-Union Standards for forest taxation (1992) - Edited by V.V. Zagreev, M.(in Russian).

Carbon in ecosystems of forest and swamps of Russia (1994). Edited by V.A. Alekseev and P.A.Berdsi - Krasnoyarsk, 170 pp.(in Russian).

Forest Resources of Europe, CIS, North America, Australia, Japan and New Zealand. Global Forest Resources Assessment 2000 (2000). Main Report No17, UN-ECE/FAO, 445 p.