Προκλήσεις για την αειφόρο διαχείριση των Μεσογειακών δασών σε συνθήκες κλιματικής αλλαγής

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1 Erasmus+ Staff Teaching Προκλήσεις για την αειφόρο διαχείριση των Μεσογειακών δασών σε συνθήκες κλιματικής αλλαγής ΗΜΕΡΙΔΑ ΔΙΑΧΕΙΡΙΣΗ ΑΠΟΒΛΗΤΩΝ Σάββατο 14 Μαΐου 2016 ΙΔΡΥΜΑ ΜΙΧΑΛΗΣ ΚΑΚΟΓΙΑΝΝΗΣ

2 CO 2 pollution and Global Warming Svante Arrhenius ( ) was a Swedish scientist that was the first to claim in 1896 that fossil fuel combustion may eventually result in enhanced global warming. He proposed a relation between atmospheric carbon dioxide concentrations and temperature.

3 CO 2 and Global Warming NOAA Figure SPM.1 Observed global mean combined land and ocean surface temperature anomalies, from 1850 to 2012 from three data sets & map of the observed surface temperature change from 1901 to 2012 derived from temperature trends determined by linear regression from one dataset (IPCC 2013).

4 CO 2 and Greenhouse gases Figure SPM.5 Radiative forcing estimates in 2011 relative to 1750 and aggregated uncertainties for the main drivers of climate change (IPCC 2013).

5 Impacts of Climatic Change (Meinshausen et al ; IPCC 2013) Drought Impact JJA-end of 21 st century (IPCC 2oo7) Mid latitude regions of the world (but not only ) are expected to be affected by higher drought stress as a result of global warming

6 Observed Impacts of Climatic Change Figure SPM.2 Widespread impacts in a changing world. (A) Global patterns of impacts in recent decades attributed to climate change, based on studies since the AR4 I (IPCC 2014).

7 Impacts of Climatic Change Assessment Box SPM.1 Figure 1 A global perspective on climate-related risks. Risks associated with reasons for concern are shown at right for increasing levels of climate change (IPCC 2014).

8 With how much CO 2 do we pollute the atmosphere each year? In 2010, gross annual Greenhouse Gas (GHG) emissions totalled ~50 GtCO 2 -equivalent. Ocean and land sinks absorb just over 50% of the emissions resulting in net atmospheric emissions increasing by around 22 GtCO 2 pa and therefore an average ~3 ppm increase of atmospheric CO 2 concentration per year, although the fraction absorbed by these sinks is falling (Le Quéré et al. 2009)

9 With how much CO 2 can we still pollute the atmosphere? Carbon budgets represent our best estimates of the amount of CO 2 that may be released into the atmosphere before it becomes unlikely that the 2 C target can be avoided. Based on the latest IPCC work the current cumulative carbon budgets are 900, 1050, and 1,200 GtCO 2 under 66%, 50%, and 33% probabilities, respectively (IPCC 2013).

10 When will we have surpassed the 2 C safety margin? 900 GtCO 2 / 22 GtCO 2 per year = ca. 41 years from now

11 What can be done? Typology for the five responses to anthropogenic climate change (Heyward 2013)

12 What can be done? Negative Emissions Technologies (NETs) While mitigation options address the root cause of anthropogenic climate change by limiting cumulative GHG emissions, they may be insufficient to deliver the scale and pace of emission reductions required to keep atmospheric concentrations of GHGs within tolerable boundaries (UNEP, 2013). In the future it may be necessary to deploy NETs at scale so as to capture and sequester CO 2 from the atmosphere directly or indirectly (Caldecott et al. 2015).

13 What can be done and at what cost? Summary of six of the most widely discussed NETs (Caldecott et al. 2015).

14 Carbon stocks and fluxes in Mediterranean forests Forest ecosystems play a key role in the global carbon cycle and climate regulation, since carbon is exchanged naturally and continuously between forests, soils and the atmosphere through photosynthesis, respiration, decomposition and combustion.

15 Carbon stocks and fluxes in Mediterranean forests Of all land-use types, forests have the largest carbon storage capacity. Carbon is stored both in aboveground (wood, leaves and litter) and belowground (root) biomass, as well as in soils (e.g. in the form of soil organic carbon) (Bolin et al., 2000; IPCC, 2007a). Globally, forests store about 77 percent of the carbon contained in the aboveground vegetation biomass and 42 percent of the top 1 m of soil carbon (Bolin et al., 2000).

16 How much can Mediterranean forests contribute to removing CO 2 from the atmosphere? Mediterranean forests are estimated to sequester tones of carbon per ha annually (Merlo and Croitoru, 2005); that is, between 0.8 and 90 million tones of carbon per year..in addition to performing other valuable ecosystem services such as water and climate regulation, the provision of wood and nonwood products and amenity, and biodiversity conservation.

17 How much can Mediterranean forests contribute to removing CO 2 from the atmosphere? Mediterranean forests are estimated to sequester tones of carbon per ha annually (Merlo and Croitoru, 2005); that is, between 0.8 and 90 million tones of carbon per year. forest cover is expanding in the north of the Mediterranean region (by ha per year between 2000 and 2005), while it is stable or slightly increasing in the SEMCs (increasing overall in that subregion by ha per year between 2000 and 2005, despite limited forest cover and forestation potential FAO, 2011).

18 Mediterranean forests can be a significant carbon sink The economic value of carbon storage in Mediterranean forests (latitude o N) ranges between US$37 billion and US$63 billion, i.e. 13 percent of the forests total economic value (for the IPCC climate change scenarios A1 and B2, respectively, with 2050 as the horizon). This economic value is smaller than that of forests from central northern Europe (latitude o N; US$117 billion to US$190 billion), but higher than that of forests in northern Europe (latitude o N; US$11 billion to US$23 billion) and Scandinavian Europe (latitude o N; US$32 billion to US$35 billion), (Ding et al., 2011).

19 How much can Mediterranean forests contribute to removing CO 2 from the atmosphere and securely storing it? Drought Impact JJA-end of 21 st century (IPCC 2oo7)

20 Significant changes in distribution of forests & Tree Mortality Climate-driven projected changes in vegetation often are represented as maps of spatial change (A, B). Implicit and potentially overlooked in such presentations is the underlying widespread tree mortality (C, D)(see Allen et al. 2o15 and references their in)

21 Drought Induced Tree Mortality Global Scale Locations of substantial drought- and heat-induced tree mortality around the globe since 1970, documented by peer-reviewed studies. (see Allen et al. 2o15 and references their in)

22 Drought Induced Tree Mortality Global Scale Locations of substantial drought- and heat-induced tree mortality around the globe since 1970, documented by peer-reviewed studies. (see Allen et al. 2o15 and references their in)

23 Mediterranean The Mediterranean has experienced intense drought conditions in recent decades that have also had a strong impact in its eastern basin. Observed time series of Mediterranean (30N-45N; 10W-40W) cold season (Nov- Apr) precipitation for (left) and the change for minus (right), (Hoerling et al. 2012).

24 Europe-N. Africa Pinus sylvestris Pinus sylvestris Recent drought intensification has increased forest mortality Pinus brutia, Samos Island, Greece 26 b Numbers=Areas of Forest Die-back Sarris et al. (2007) Cedrus atlantica (Allen et al. 2010)

25 Impact assessment using tree-rings Tree-ring series can be used to reconstruct past variations in precipitation, temperature, soil moisture, river flows, floods, frequency of droughts, forest fires, major forest pest outbreaks, pollutants and other phenomena important to the management of natural resources and the natural and human environment. 3, 4, 5, 6, 7, 8, 9, 10,11, 12, 13, 14, 15, 16 17,18, 19, 20, 21, 22, 23, 24

26 Tree-ring records indicate unprecedented growth decline The recent decline in tree ring width (TRW) for low elevation pines in the eastern Mediterranean (4 island regions) appears to be the most significant at least since the late 18 th Century (Sarris et al. 2011). n=82 trees 10-year running annual precipitation (Meinshausen et al ; IPCC 2013) The recent TRW decline clearly matches that in annual rainfall (top) and not the increase in atmospheric CO2 concentrations (bottom)

27 Changes in species communities Exceptional damage from drought was also recorded for the evergreen sclerophyllous (macchia) scrub vegetation on Samos Island, Greece in the year Juniperus phoenicea & Phillyrea latifolia were affected most, Quercus coccifera & wild Olea second, Pistacia lentiscus least (Körner, Sarris, Christodoulakis. 2005) Annual rainfall, Samos Island Greece Photos: C. Körner

28 Under intense drought such moisture pools supplied by rainfall of even of the past 5-6 years were the main drivers of tree growth. Not the case under wet climate conditions. When they dry out, pines may be pushed very close to their survival limits and can even be desiccated, as was documented in the eastern Aegean island of Samos in late summer 2000, even for 80-years old trees (Sarris et al. 2007). For similar responses from summer 2011 at even more arid conditions see Dorman et al. (2015) Sarris et al (Sarris et al. 2007).

29 What are the limits of forest management? Location of the sampled sites and meteorological stations (Dorman et al in Oecologia)

30 Forests and drought (Dorman et al in Oecologia) Ground photographs of the 10 study sites, taken at the time of sampling (fall 2012 spring 2013)

31 Do thinner stands of stressed trees perform better in dry years in the most arid places? Dry Year Wet Year (Dorman et al in Oecologia)

32 Do thinner stands of stressed trees perform better in dry years in the most arid places? Dry Year Wet Year NO (Dorman et al in Oecologia) NO

33 Climatic Change, Forests and Fire Burnt area index (standardization by mean) * of Sep-Aug mean precipitation for central, southern Greece, western and o o o o southwestern Turkey (35-40 N, E) GREECE (EFFIS 2007) % * -18% * Year

34 Mega-fires are the largest threat for securely storing carbon Burned biomass and emission estimates from forest fires up to 31 August 2007 by country (EFFIS 2007)

35 What creates mega-fires in Mediterranean forests? Mt. Taygetos overlooking Sparta Southern Greece

36 Assessing fire risk Reconstructed the mountain s fire history from Pinus nigra fire-scars (Christopoulou et al. 2013) Photo: D. Sarris Photo: SF Arno, USDA Forest Service Agee JK (1998) in Richardson DM (ed) * Reconstructed climate (mid to late-fire-season drought) for the mountain using Pinus nigra and Abies cephalonica tree-rings for the last 150 years (Sarris et al. 2014)

37 The dates refer to the 10 most extensive fires on Mt. Taygetos (Sarris et al. 2014)

38 Drought increase is behind recent large scale fires 4 Largest Fires In the last 150 years 7/10 large fires Mt. Taygetos experienced, were associated with below normal P or above normal T max. Only the recent and large fires (1998 and 2007) had both low P and high T max, also confirmed from long-term meteorological data. (Sarris et al. 2014)

39 But what happens if fuel availability also increases? The synergy between climate and fuel availability (reduced herbivory & land abandonment) can explain the very high intensity of 1998 and 2007 fires that burned mostly as stand-replacing crown fires on Mt. Taygetos (Sarris et al. 2014). Pinus nigra stands on Mt. Taygetos after the 2007 fire Photo: D. Sarris

40 How can we improve fire danger prognosis? Living fuel at low altitudes in semi-arid regions is composed of deeprooted plants (phreatophytes) Olea sp. Pistacia sp. Photo: D. Sarris Photo: D. Sarris

41 How can we improve fire danger prognosis? Living fuel at low altitudes in semi-arid regions is composed of deep-rooted plants (phreatophytes) Arbutus sp. Quercus sp. Photo: D. Sarris

42 How can we improve fire danger prognosis? Living fuel at low altitudes in semiarid regions is composed of deeprooted plants (phreatophytes) Juniperus sp. Cupressus sp. Photo: D. Sarris Photo: D. Sarris

43 How can we improve fire danger prognosis? Deep-rooted plants survive the Mediterranean dry season by utilizing moisture accumulating belowground from past rainfall events (see Sarris et al for more details). Pinus sp. This also influences the moisture content of phreatophytes in summer when acting as living fuel for forest fires. Photo: D. Sarris & D. Christodoulakis (Sarris and Koutsias 2014)

44 How can we improve fire danger prognosis? Only annual (mostly winter) P (not spring nor summer P) has a significant effect on fire spread in the driest regions! TMVB MMVB (Sarris and Koutsias 2014)

45 Deep rooted species may help securely store carbon deep below ground Future prospects Test for carbon sequestration and deeper =safer carbon storage by deep roots underground. (Sarris et al. 2013)

46 Last but not least ouc.ac.cy Available Online at Documentary film on Desertification and the role of climate change, land and forest management Thank you for your kind attention!