Carbon sequestration in conditions of Slovak republic and Danube floodplains

1. Carbonsequestration in conditionsof Slovak republic and Danubefloodplains Andrej Kovarik

2. Country conditions of Slovakia Mild climate with annual average about 10°C in southern parts Initially almost fully forested Recently 41% landscape surface forested Only fragments - about 2% are floodplain forests River regulation has been the principal immediate cause of wetland loss and consequently also loss of biodiversity. Most devastated and endangered forest habitat

3. Land use matrix

4. Land use changes

5. Carbon sequestration in Gg

6. Methodology,datasourcesand calculations Results from national forest statistics, NFI and soil inventory (forest and agriculture soils) Non-CO2 gases – forest fires, liming of agricultural soils Calculations from livingbiomass, soilorganic C, biomassburning and liming

7. Forest land – living biomass Woodincrement – based on biomass expansion factors (BEFs)calculationaccording to individualtreespecies Woodharvestfrom national forest statistics Calculationsbased on annualdata

8. BEFs and C-fraction – treespecies in Slovak conditions

9. Soil organic carbon Calculations for 4 land use changes SOC data from national soil inventory (mainly for forest and agricultural soils) Calculation units – soil types Calculations based on annual data Default time period T = 20 years

10. SOC for land use and soil types

11. Carbon sequestration in floodplain forests conditions Not evalueted yet in Slovakia Thesoil, alongwithgeologicformations, isrecognizedasthe most stablereservoirsforstoring C Organiccarboncontentissignificantlygreater in hydricsoilsthaninnon-hydricsoils. Danube floodplain forests stands mostly on gravel based – mineral soils

12. Carbon content of the mineral soil is increasing with successional stage of the floodplain chronosequence. Increasing production of forest biomass per se may not necessarily increase the SOC stocks. Rate of soil organic carbon (SOC) sequestration, and the magnitude and quality of soil C stock depend on the complex interaction between climate, soils, tree species and management, and chemical composition of the litter

13. In disturbed sites, for instance suitable for re-naturalization, regression analyses indicates that it may take over 50 years for carbon levels to reach 75% of levels on reference site Many parts of the Danube floodplainsare managed as intensive hybrid poplar plantations Monocultures had reduced biodiversity significantly - plantations provides habitat only for some species, often non-native and invasive ones.

14. Connection with wetlands wetlands which are closely connected with floodplain forests, comprise a small proportion of earth’s terrestrial surface, but they contain a significant proportion of terrestrial carbon pool Always thing of both! Significantamountofcarbonstored in wetlandsoils, peats, litter, and vegetation – 500 – 700 GT globaly. Globalytheammountstored in wetlandsmayapproachthetotalamountofatmosphericcarbonthatisestimatedat 753 GT!

15. wetlands growing on mineral soils associated with riverine systems - like here in Danube floodplains, have typically higher productivity and standing biomass (so also carbon sequestration) than fens and bogs which have organic soils.

16. Carbon fluxes – inputs Organic matter, derived from either aboveground and belowground biomass production, is the principal source of soil carbon. Litter production in bottomland hardwood forests is usually about half of aboveground net primary productivity (NPP) Range of aboveground NPP of bottomland hardwood forests, temperate wetland forests and floodplain forests is similar – from 20 to 2000g/m2

17. Aboveground NPP Forest floor organic matter increases rapidly during early secondary succession, with a maximum of about 700 g/m2 and decreasing to 340 g/m2 during the later seral stages. Carbon content in the forest floor also reflects this pattern, with levels greatest during early succession and declining thereafter Changes in carbon pools of the forest floor are primarily driven by changing levels of forest floor biomass in the various stages of succession, rather than element concentrations.

18. Aboveground NPP Herbaceous material declines during succession from about 75% in an early stage to <1% in the latest seral stage Conversely, the amount of woody foliage increased from 6.7 to more than 70% in late succession. Abovegroundnetprimaryproduction (NPP) in youngriparianforestsrapidlyapproached and exceeded NPP ofthe more matureriparianforest. Woodydebris in theseriparianforestscomprised a relativelysmallcarbonpool.

19. Belowground organic matter inputs are important source of soil carbon. Range of belowground NPP varies according local hydrological conditions from about 10 to 110 %. Stump and root biomass may reach as much as 90 % of the belowground biomass. Important wetland, bottomland hardwood and floodplain forests soil component is mycorrhizal fungi. Poorly drained soils have significantly higher rates of mycorrhizal fungi infection and greater belowground allocation of carbon than in better drained soils.

20. Carbonstorage in short-rotationpoplarplantations highersoil C sequestrationrates in plantationculturethan in naturalsystemsdue to thehigherplantingdensitiesoffastergrowingtreesputtinggreaterquantitiesof C intothesoil Studieshaveacknowledgedthepossibilityofsoil C accumulations in rotationsforup to 30 years. Asrotationlengthshortens, gain in soil C candecrease and cause a long-termdecline in soil C

21. Variouspatternsofchange in soil C observed Netlosses in soil C duringtheinitialyearsoftreecropestablishment, butincreasesafter about 5 years growth of hybridpoplars Rateofsoil C sequestration in shortrotationplantationswouldequal or surpassnaturallyregeneratingwoodlands.

22. BROZ in Danube floodplains

23. Changingof forest management

24. Leaving of dead wood

25. Designation of new nature reserves Afforestation of arable land

26. Restoration of grasslands

27. Restoration of wetlands

28. Conclusion There are environmentalimplicationsfortheuseofPopulus and othershortrotationintensiveculturecrops in sequesteringatmospheric C by storingit in terrestrialpools but in respect to biodiversity, and real nature conservancy,only on new unforestedsites – forexample on agrisoilsalongtherivers.

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