University of West Hungary Faculty of Forestry Pál Kitaibel Doctoral School of Environmental Sciences Modelling the future distribution of beech at low-elevation xeric limits - comparison of empirical and stochastic models DOCTORAL (PHD) DISSERTATION Ervin Rasztovits Supervisor: Prof. Dr. Csaba Mátyás Sopron 2011 2 Modelling the future distribution of beech at low-elevation xeric limits - comparison of empirical and stochastic models Értekezés doktori (PhD) fokozat elnyerése érdekében készült a Nyugat- magyarországi Egyetem Kitaibel Pál Környezettudományi Doktori Iskolájának Biokörnyezet-tudomány programja keretében Írta: Rasztovits Ervin Témavezető: Prof. Dr. Mátyás Csaba Elfogadásra javaslom (igen / nem) …………………………….. aláírás A jelölt a doktori szigorlaton ........%- ot ért el. Sopron, ………………………………….. …………………………… .............................................. a Szigorlati Bizottság elnöke Az értekezést bírálóként elfogadásra javaslom (igen / nem) Első bíráló (Dr. ………………………………) igen / nem …………………………… (aláírás) Második bíráló (Dr. ………………………………) igen / nem ………………………… (aláírás) A jelölt az értekezés nyilvános vitáján ………..%-ot ért el. Sopron, ................................... ...................................... a Bírálóbizottság elnöke A doktori (PhD) oklevél minısítése:……………………………… .................................. Az EDT elnöke 3 4 Contents Abstract / Kivonat……………………………………………………………………………………………………. 7 1 Introduction .............................................................................................................. 8 2 Literature review ..................................................................................................... 10 2.1 Climate change .......................................................................................................... 10 2.1.1 Global changes ................................................................................................... 10 2.1.2 Climate change in Europe .................................................................................. 11 2.1.3 Climate change in Hungary ................................................................................ 11 2.1.4 Uncertainty of climate models ........................................................................... 14 2.2 The effect of global climate change on forests ......................................................... 16 2.2.1 Drought-induced tree mortality and forest die-off ............................................ 16 2.2.2 Plant physiology and biotic agents ..................................................................... 19 2.2.3 Climate change and future mortality rate ......................................................... 20 2.2.4 Decline model (factors and their interactions) .................................................. 20 2.3 Ecology of beech ........................................................................................................ 22 2.3.1 The current distribution range of European beech ........................................... 22 2.3.2 Ecological and climatic constraints of the distribution of beech ....................... 24 2.3.3 Beech provenace trials ....................................................................................... 27 2.4 Beech in Hungary ....................................................................................................... 27 2.4.1 Beech associations in Hungary ........................................................................... 29 2.4.2 Beech decline in Hungary ................................................................................... 30 2.5 Distribution modelling ............................................................................................... 34 2.5.1 Distribution models ............................................................................................ 34 2.5.2 Process based models ........................................................................................ 37 2.5.3 Hybrid models .................................................................................................... 38 2.5.4 Empirical models ................................................................................................ 38 2.5.5 Critical evaluation ............................................................................................... 39 2.6 The problem of modelling the xeric limit .................................................................. 39 2.7 Distribution modelling of European beech ............................................................... 40 2.7.1 Distribution modelling of beech on European scale .......................................... 40 2.7.2 Distribution modelling of beech on national level ............................................. 41 2.7.3 Distribution modelling of beech in Hungary ...................................................... 44 1.1.1. Gaps .................................................................................................................... 52 3 Materials and Methods ........................................................................................... 53 3.1 Climate database ....................................................................................................... 53 3.1.1 Climate data for current conditions (1950-2000) .............................................. 53 3.1.2 Meteorological database (1975-2006) ............................................................... 53 3.1.3 Scenarios for the future ..................................................................................... 58 3.2 Species distribution models (SDMs) using long-term climate data .......................... 61 3.2.1 The ModEco platform ........................................................................................ 61 3.2.2 Environmental layers .......................................................................................... 61 3.2.3 Factor analysis .................................................................................................... 64 3.2.4 Modelling methods ............................................................................................ 65 3.2.5 Accuracy assessment .......................................................................................... 67 3.3 Extreme drought event based empirical model (EM) ............................................... 69 3.3.1 Study area ........................................................................................................... 69 5 3.3.2 The extreme drought period of 2000-2003 ....................................................... 73 3.3.3 Forest data.......................................................................................................... 75 3.3.4 Vitality response of beech .................................................................................. 75 4 Results .................................................................................................................... 77 4.1 SDMs using long-term climate data .......................................................................... 77 4.1.1 Performance of presence-only methods ........................................................... 77 4.1.2 Performance of presence/absence classification methods ............................... 79 4.1.3 Factor importance analysis ................................................................................ 84 4.2 Extreme drought event based empirical model (EM) ............................................... 85 4.2.1 Vitality response of beech .................................................................................. 85 4.2.2 Simulation results of beech vitality in the future ............................................... 85 5 Discussion ............................................................................................................... 89 5.1 Performance of the SDMs ......................................................................................... 89 5.1.1 Actual and potential current distribution .......................................................... 89 5.1.2 Future potential distribution .............................................................................. 90 5.1.3 Regional differences ........................................................................................... 91 5.1.4 Correlates of beech distribution ........................................................................ 92 5.2 Performance of the EM ............................................................................................. 93 5.3 Comparison of stochastic (BP-ANN) and empirical model ........................................ 94 5.4 Outlook ...................................................................................................................... 95 6 Summary ................................................................................................................. 97 6.1 Introduction ............................................................................................................... 97 6.2 Materials and methods.............................................................................................. 98 6.3 Results ........................................................................................................................ 99 7 Utilization of the results ......................................................................................... 103 7.1 Utilization of the meteorological database ............................................................