Effetti del Global Change su crescita e funzionalitá delle foreste italiane Esperimenti e osservazioni F. Magnani 1, A. Barbati 2, M. Borghetti 3, G. Matteucci.

Presentazione sul tema: "Effetti del Global Change su crescita e funzionalitá delle foreste italiane Esperimenti e osservazioni F. Magnani 1, A. Barbati 2, M. Borghetti 3, G. Matteucci."— Transcript della presentazione:

1 Effetti del Global Change su crescita e funzionalitá delle foreste italiane Esperimenti e osservazioni F. Magnani 1, A. Barbati 2, M. Borghetti 3, G. Matteucci 4, S. Raddi 5, G. Tonon 6 Effetti del Global Change su crescita e funzionalitá delle foreste italiane Esperimenti e osservazioni F. Magnani 1, A. Barbati 2, M. Borghetti 3, G. Matteucci 4, S. Raddi 5, G. Tonon 6 1 Univ. Bologna, 2 Univ. Tuscia, 3 Univ. Basilicata, 4 CNR-IBAF, 5 Univ. Firenze, 6 Univ. Bolzano ”Too much of a good thing” Deposizioni di N ed ecosistemi forestali in Italia Roma, 16 maggio 2014 ”Too much of a good thing” Deposizioni di N ed ecosistemi forestali in Italia Roma, 16 maggio 2014

2 European (and NAmerican) forests are growing faster than they used to, and sequestering more C. Possible causes have been explored by the EU RECOGNITION project (Karjalainen et al. 2008): Global Change and forest growth C sequestration in Europe, 1950-2000: possible causes changes in the age structure of European forests: still ageing after WWII disturbance and past intensive management? changes in management practices (litter raking, residues collection, grazing …; fertilization) recovery of SOM and soil fertility Ciais et al. Nature Geoscience 2008 changes in forest species composition (eg close-to-nature forestry) growth (and perhaps NEP) stimulated by temperature changes GPP and growth affected by changes in solar irradiance and diffuse fraction growth and NEP stimulated by rising atmospheric CO 2 forests could benefit from atmospheric N deposition

3 New contrasting evidence on C-N interactions has emerged over the last few years. Focusing on annual rates, sensitivities range from < 70 (long-term fertilization experiments) to 200 g C / g N (regional transects). The reason could lie in the time frame being considered N deposition effects on forest growth and C sequestration N deposition effects: contrasting evidence Magnani et al. 2007, Nature Hyvönen et al. 2007, Biogeochemistry 50 (trees) + 20 (soil) g C / g N 200 g C / g N (total!)

4 The empirical observation of a co-variation between N addition and C sequestration has been questioned as spurious: -Sutton et al. (2008): N deposition could co-vary with temperature (real driver) -Hogberg (2012): N deposition could co-vary with background site fertility (real driver) through land-use history and development N deposition effects on forest growth and C sequestration the problem of co-variation with temperature and land-use These doubts can only be answered by a combination of approaches: 1.regional transects, variable N deposition (but also climate!): ICP L2, NFI 2.temporal changes in growth (chronosequences + growth rings): RECOGNITION 3.manipulative studies: long-term N fertilization 4.process-based models as integrating tools

5 MIUR - Ministero dell’Istruzione, dell’Università e della Ricerca PROGRAMMI DI RICERCA SCIENTIFICA DI RILEVANTE INTERESSENAZIONALE Effetti del cambiamento globale su produttività e forcing radiativo delle foreste italiane: metodi innovativi di analisi retrospettiva, sperimentale e prognostica #AcronimoIstituzione e CUPResponsabileEmail 1UNIBOAlma Mater Studiorum – Università di Bologna (J38C13001510001) Federico Magnani Claudio Ciavatta (Paola Gioacchini) federico.magnani@unibo.it claudio.ciavatta@unibo.it paola.gioacchini@unibo.it 2UNIBASUniversità degli Studi della Basilicata (C38C13000190001) Marco Borghetti Luigi Todaro (Tiziana Gentilesca) marco.borghetti@unibas.it luigi.todaro@unibas.it tiziana.gentilesca@unibas.it 3UNIBZLibera Università di Bolzano (B58C13000740008) Giustino Tonongiustino.tonon@unibz.it 4UNIFIUniversità degli studi di Firenze (B18C13001590001) Sabrina Raddisabrina.raddi@unifi.it 5UNITUSUniversità degli Studi della Tuscia (J88C13000900001) Anna Barbati (Piermaria Corona) barbati.sisfor@unitus.it piermaria.corona@unitus.it 6CNRCNR – IBAF (B88C13002040001) Giorgio Matteuccigiorgio.matteucci@isafom.cs.cnr.it 6bMPFCRA – MPF(Patrizia Gasparini) (Gianfranco Scrinzi) patrizia.gasparini@entecra.it gianfranco.scrinzi@entecra.it

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7 Task 1 – Modelling simulating effects of CO 2, N and climate at national level Forest growth and biogeochemistry estimated by HYDRALL-CENTURY model Distribution of reactive N deposition and its temporal dynamics (1960-2050) estimated using the TM4 model CRU-TYN climate data 1961- 2050 SPADE-2 soil database for soil characteristics (texture, C, N) Model applied at 1 km resolution for the whole of Italy, by forest type (CORINE Level 4)

8 HYDRALL-RothC, spazializzato 1km a scala nazionale (modellizzazione diagnostica) HYDRALL- CENTURY, puntiforme (modellizzazione diagnostica) Task 1 – Modelling simulating effects of CO 2, N and climate at national level

9 Task 2 – Ecosystem fertilization review of N fertilization studies: a complex story  C n =  C g – Mortality  C n = net C sequestration in biomass  C g = gross C sequestration in biomass

10 Task 2 – Ecosystem fertilization growth response in coniferous species  C g response to additional N in ECM species Only experiments with at least 3 N levels (C, N1, N2) for non-linear effects (n=8) Pinus sylvestris, P. resinosa, P. banksiana, Picea abies Response normalized to common value of additional N Fitted segmented empirical model (Mitscherlich + linear decline)

11 Spinning the wheel: average sensitivity of net N mineralization to accumulated N input, possibly mediated by changes in soil C:N ratio Task 2 – Ecosystem fertilization review of N fertilization studies: long-term changes in soil processes

12 Task 2 – Ecosystem fertilization review of N fertilization studies: long-term changes in soil processes Forest long-term N fertilization in 2 Fagus sylvatica forests (+ 1 F. sylvatica, 1 Quercus pubescens by UNIBZ) Replicated (n=3) 30x30 m plots Combine with long-term monitoring at CONECOFOR sites Changes in forest (gross, net) increments, C accumulation in plants + soil Changes in soil processes (net N mineralization, nitrification + leakage) GHG emissions (CO 2, N 2 O, CH 4 ; ex-situ)

13 Task 3 – Reconstruction of past growth changes diachronic analysis in Fagus sylvatica chronosequences Analysis of past changes in tree and stand growth in Fagus sylvatica 5 chronosequences along Italy, associated with CONECOFOR sites Stem analysis for assessment of dominant height and total volume (see RECOGNITION) C and O isotope analysis for the assessment of functional determinants (transpiration, WUE) 2 additional Picea abies chronosequences in Italy and Germany

14 Effetti del Global Change su crescita e funzionalitá delle foreste italiane Esperimenti e osservazioni federico.magnani@unibo.it Effetti del Global Change su crescita e funzionalitá delle foreste italiane Esperimenti e osservazioni federico.magnani@unibo.it