Momchil Panayotov & Stefan Yurukov University of Forestry, Sofia, Bulgaria

1. Project “Subalpine forest development in Bulgarian Mountain Forests under climate change”IZEBZO_143109 Momchil Panayotov & Stefan Yurukov University of Forestry, Sofia, Bulgaria Sofia, 22 May 2014, Mid-term Meeting, Project 143109 “Subalpine forest development in Bulgarian Mountain Forests under climate change”

2. Objectives • The Balkan Peninsula: • One of the most threatened regions under the climate change scenarios Source: Raisinen et al., 2004 • Could mountain forests be threatened? • More natural disturbances (fires, windthrows, bark-beetles) • Regeneration failure (saplings tolerance to drought, mycorrhiza) • Endemic species (P. peuce; P. heldreichii) – what’s their future? Sofia, 22 May 2014, Mid-term Meeting, Project 143109 “Subalpine forest development in Bulgarian Mountain Forests under climate change”

3. Project outline • The Project: • Three “Tasks”; “three teams”, which help and complement each other: • Task 1 “Natural dynamics and disturbance regimes of representative subalpine forests ecosystems ” • Task 2 “Investigation the responses of mature trees in cases of climate extremes” • Task 3 “Study the performance of saplings in drought stress and mycorrhizal symbiosis” • Project leaders – Prof. Yurukov (BG), Dr. Peter Bebi (SLF Switzerland) • Swiss Advisors – David Frank, Holger Gartner, Fank Graf, Melissa Dawes (WSL; SLF-WSL) • Bulgarian team - mostly PhD students & teaching assistants in the University of Forestry, Sofia; Sofia, 22 May 2014, Mid-term Meeting, Project 143109 “Subalpine forest development in Bulgarian Mountain Forests under climate change”

4. WORKING TASKS • Task 1: Natural dynamics and disturbance regimes of representative subalpine forests ecosystems • Central research questions which are examined within this task are: • On which spatial and temporal scales do natural disturbances occur in the subalpine forests in Bulgaria? • 2) What is the role of historical disturbances, management and species composition in determining subsequent disturbances? • 3) What is the importance of natural disturbances for forest structure and functioning of subalpine forests in Bulgaria? Sofia, 22 May 2014, Mid-term Meeting, Project 143109 “Subalpine forest development in Bulgarian Mountain Forests under climate change”

5. WORKING TASKS • Task 1, sites: • Parangalitsa forest reserve (Norway spruce and mixed, Rila Mts.) • Disturbance regime and natural dynamics • Regeneration after disturbances (50 yr. period, 30 yr. period) • Beglika forest reserve (Norway spruce, subalpine forest, Rhodopa Mts.) • Age structure/disturbance regime history • Regeneration process after small-scale disturbances • Bistrishko braniste reserve (Norway spruce, Vitosha Mts) • Age structure/disturbances • Regeneration after disturbances of different kind – windthrow, bark-beetle, fire • Dzindzhiritsa-Baiuvi dupki reserve (Pinus heldreichii, Pinus peuce forests): • General role of fires for Pinusheldreichiiand P. peuceforests; Was regeneration successful enough and if there are more fires, are there general long-term risks for these forests? Sofia, 22 May 2014, Mid-term Meeting, Project 143109 “Subalpine forest development in Bulgarian Mountain Forests under climate change”

6. WORKING TASKS • Task 1, results: • 1. We have completed the disturbance regimes studies for Parangalitsa and Bistrishko braniste forest reserves (started before): • These spruce forests were dominated by medium to large-scale windthrows • Human influence in the past (Bistrishko braniste) affected the present disturbance situation (a combination of large-scale windthrow, bark beetle outbreak and fire) • Climate plays role in tree mortality – mostly drought affects trees in high competition stage + effect on bark beetle outbreaks (most worrying) • 2. We are working on post-disturbance regeneration studies: • Very high influence of “advanced regeneration” – more diverse forests are resilient and are capable of better overcoming the negative effects of natural disturbances; Traditional management highly undesired in modern climate-risk situation • 3. Fires played major role in Balkan-endemic Pinus peuce-Pinus heldreichii forests; These forests seem to be well-adapted to periodic fires Sofia, 22 May 2014, Mid-term Meeting, Project 143109 “Subalpine forest development in Bulgarian Mountain Forests under climate change”

7. WORKING TASKS • Task 2: Investigation the responses of mature trees in cases of climate extremes • Sub-task 2.1. How did mature trees perform during past climate extremes? • We work on improving the longest Bulgarian Tree Ring chronologies. Now we have: • ~750 yrs. tree ring width P. heldreichii • ~250 yrs. MXD P. heldreichii, excellent proxy for summer temperaures • ~350 yrs. tree ring width P. peuce (mixed signal) • ~400 yrs. tree ring width P. nigra - very good proxy for precipitation Sofia, 22 May 2014, Mid-term Meeting, Project 143109 “Subalpine forest development in Bulgarian Mountain Forests under climate change”

8. WORKING TASKS • Task 2: Investigation the responses of mature trees in cases of climate extremes Sofia, 22 May 2014, Mid-term Meeting, Project 143109 “Subalpine forest development in Bulgarian Mountain Forests under climate change”

9. WORKING TASKS • Task 2: Investigation the responses of mature trees in cases of climate extremes • Sub-task 2.1. How did mature trees perform during past climate extremes? • Is tree ring anatomy holding “a key” for better understanding of what were the extremes and how did trees perform? • We have started detailed xylogenesis studies (P. peuce and P. heldreichii), first results are very interesting • Longer “anatomical chronologies” - compare the known climate of the past century to tree ring anatomy Sofia, 22 May 2014, Mid-term Meeting, Project 143109 “Subalpine forest development in Bulgarian Mountain Forests under climate change”

10. WORKING TASKS • Task 3: Study the performance of saplings in drought stress and mycorrhizal symbiosis • If there are stronger and longer droughts – how will small trees perform? Is there “future” for the subalpine forests within the present species composition? • Controlled experiment – 4 species, 3 situations – 1) drought early in the season (June - early July); 2) drought July - Aug; 3) Control • Eco-physiological studies • Mycorrhiza studies • Anatomical studies (tree rings) of trees that died or passed the experiment alive Sofia, 22 May 2014, Mid-term Meeting, Project 143109 “Subalpine forest development in Bulgarian Mountain Forests under climate change”

11. Some aspects • General organization, problems, conclusions: • Team assembly - as initially planned, Kick-off meeting in March 2013 in Yundola; • Web pages - (slf.ch, dendrochronologybg.net) – we have feedback (ETH, other teams) • First year meeting – Jan 2014, Yundola – results discussion and planning • The PROBLEMS: • The public competitions for equipment purchases – together with the University of Forestry – long delays, problems on procedures, some equipment purchases delayed for 2014. • 2. What is going on now? • Data analysis (1st yr. results), Conference presentations, Start of filed work for year 2 Sofia, 22 May 2014, Mid-term Meeting, Project 143109 “Subalpine forest development in Bulgarian Mountain Forests under climate change”

12. THANK YOU! BIODIVEST2010, Craiova, 16-18 Sept.2010: Anatomical and morphological changes in Pinus heldreichii Christ along an altitudinal gradient in Pirin mountains

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15. WORKING TASKS Task 2: Investigation the responses of mature trees in cases of climate extremes Sofia, 22 May 2014, Mid-term Meeting, Project 143109 “Subalpine forest development in Bulgarian Mountain Forests under climate change”

16. SOME Add-ons • Quite late start of cell division – End of June. The same in 2010. • Probably due to late spring cold spells (April-May snowfalls) • Cell division till the middle of October; Both 2010 and 2011 – Late spring cold spells, but unusually warm winters; “Normal”summers

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19. SOME Add-ons • MYCORRHIZAL study • The aim of aim of experimental research is to determine whether the different humidity conditions will affect the species composition of ectomycorrhizal spectrum, how, and whether it will impact the sustainability and survivability of the plants in drought conditions. • Preliminary results: • Morphotypes of the ectomycorrhizae We found three morphotypes in PA-12-J, which are synthesized on a specialized medium (MMN and Ferry). Three morphotypes with ectomycorrhizal roots are taken for DNA analysis samples and are stored at -20 ⁰ C. Research is done also for the root systems of dead individuals for the all selected tree species in the majority of which was found carbonized and unrecognizable mycorrhizae. As a preliminary result there is a conformation, that Cenococcum geophilum play a critical role for the drought resistance tolerance of Picea abies. • DNA analysis The standard protocol for plants (Delaporta, 1983) was tested in the Joint Genomic Center, Sofia and prove to be working.

20. SOME Add-ons • Tree ring width • The “mixed signal” hinders climate reconstruction; • Yet, pointer year analysis is possible, especially in combination with other species Panayotov, M., Bebi, P., Trouet, V., and Yurukov, S. (2010) Climate signal in tree-ring chronologies of Pinus peuce and Pinus heldreichii from the Pirin Mountains in Bulgaria. Trees - Structure and Function. DOI: 10.1007/s00468-010-0416

21. SOME Add-ons Detrended tree ring width chronologies (residual versions) from Pinus heldreichii from Bunderitsa valley in Pirin Mts., Bulgaria Yundola, 20 March 2013, Meeting Project “Subalpine forest development in Bulgarian Mountain Forests under climate change”

22. Results – Maximum Latewood Density • The “Maximum Latewood Density” of P. heldreichii