Modeling impacts of climate change scenario over Turkey

Bu çalışmada izlenen yöntem, Türkiye ve çevresi üzerinde, günümüz ve gelecek için NASA-Sonlu Hacim Genel Dolaşım Modeli (fvGCM) tarafından üretilen projeksiyonların, ICTP-Bölgesel İklim Modeli (RegCM3) kullanılarak dinamik olarak ölçek küçültülmesidir. Günümüz (1961-1990, RF) ve gelecek (2071-2100, A2) simülasyonları için, Hükümetlerarası İklim Değşikliği Paneli (IPCC) tarafından belirlenmiş sera gazları emisyon senaryoları dikkate alınmıştır. A2 ve RF simülasyonlarının sıcaklık ve yağış için yapılan mevsimsel analizleri Türkiye’nin iklimsel bölgeleri üzerinde alansal ortalama alınarak ayrı ayrı incelenmiştir. A2 simülasyonuna göre, Türkiye üzerinde sıcaklıklardaki en dramatik değişim yaz mevsiminde Ege Bölgesi üzerindeki 5 ila 6 °C’ler arasındaki artıştır. Kış ayları dışındaki mevsimlerde artış, 3-4 °C arasında değişmektedir. Gelecek simülasyonundaki minimum artış, kış mevsiminden 2-3 °C olarak hesaplanmıştır. Yine A2 simülasyonunda, Doğu Karadeniz dağları boyunca uzanan bölgede kış yağışlarıdaki artış, rüzgar paterninin değişmesiyle orografik etkinin güçlenmesine bağlıdır. Türkiye’nin güneyi üzerinde de rüzgar paterninin güneyli değişimine bağlı olarak kış yağışlarında çok ciddi azalmalar (% 34) model sonuçlarında ortaya çıkmıştır. Sonbahar meviminde ise Güneydoğu Anadolu Bölgesinde yağışlarda % 50’lere varan artışlar görülmüştür. Bu artışların ana nedeni değişen rüzgar akımlarının taşıdığı nem olabilir. Gelecek iklim senaryosunda Fırat ve Dicle su havzalarını kapsayan alandaki kış yağışlarında yaşanan azalmalarla, küresel ısınmaya paralel sıcaklık artışının buharlaşmaya etkisiyle birlikte değerlendirildiğinde, model sonuçlarının hidrolojik analizlerinin önemi daha çok ortaya çıkmaktadır. Anahtar Kelimeler: İklim değişimi, bölgesel iklim modellemesi, ölçek küçültme.The Earth's climate has changed many times and fluctuated between the glacial and the interglacial periods since its formed. These changes related to natural forcings like volcanic eruptions, intense tectonic activity, solar activity and variation of Earth's orbital parameters, were sometimes very dramatic. Today, the global change we face to is different than the natural changes occurred in the past. Human-induced climate change has been taken into consideration extensively within the last decade more than ever. Recent advances in both climate observing systems and methodologies to detect the climate change, as well as broader global coverage of observations help scientists to better understand the climate system. Scientific studies which are led by IPCC (Intergovernmental Panel on Climate Change) showed that dominance of anthropogenic effect on global warming is indisputable (IPCC, 2007). Regional climate change modeling has been applied to many different areas such as agriculture, seasonal forecasting, hydrology applications, paleoclimate and climate projections. Because of its ability to resolve sharp gradients and contrasts in the surface conditions, the regional climate modeling approach yields more accurate and spatially detailed information. In this study,  the ICTP-Regional Climate Model version 3 (RegCM3) has been used to downscale present and future scenario simulations generated by the NASA-Finite Volume General Circulation Model (fvGCM) over Turkey and its surroundings. The present-day (1961-1990, RF) and the future climate change simulations (2071-2100, A2) are based on the IPCC Greenhouse Gases emissions, which are CO2, CH4, N2O, and CFC11- CFC12. Emission scenarios for these gases have been implemented into the radiation scheme for the simulations and, relatively high resolution of 30 km is adopted to resolve the complex topography of the domain. The role of the domain characteristics such as complex land-sea distribution determines the sub-regional climatic features and spatial climate variability. This diverse climatic structure of the region brings great challenge for regional climate modeling. Levantine Sea, Aegean Sea and Black Sea are main moisture sources of the Turkey and its surrounding regions. A2 simulation results which correspond future climate indicate that warming over Turkey's climatic zones is in the range of 2-5 °C. Summer temperature changes are more dominant in the A2 scenario. This pattern has also been observed for neighboring countries. Summer heat wave conditions over Aegean region (5 °C increase) are more obvious in the area averages than in the spatial pattern based model results. The difference between the summer and winter change is about 3 °C and it could play an important role in contributing to temporal shifts of the transition seasons. In addition, warming in winter over eastern and southeastern of Turkey which have higher altitudes are nearly 1 °C higher than for Marmara and Aegean regions which have lower altitudes. Autumn temperature changes for all regions are affected by the extension of the summer season extension due to the global warming. Most significant precipitation changes in A2 scenario have been occurred over the Mediterranean region of Turkey in winter and over the Southeastern of Turkey in autumn. Our analyses show a 34% decrease over Mediterranean region and it is related to the change in the atmospheric circulation which in turn causes reduced orographic forcing. The same circulation change also enhanced orographic forcing especially over the east of the Black Sea region and results in significant precipitation increase. Decreases over the Aegean and Southeastern regions are around 20% in winter. Autumn precipitation over Southeastern region increased as high as 48%. Flow pattern changes which also affected Iraq and Syria are consistent with enhanced moisture availability over this region which may account for the major precipitation increase. All precipitation changes in winter and autumn are also statistically significant. The amount of precipitation over Turkey in summer season is very little except eastern Black Sea region. Therefore, percent changes for summer precipitation over all of regions could not be meaningful to discuss. Analyses of A2 simulation show that combined effect of precipitation decrease and evapotranspiration increase related to temperature increase could play major role to reduce water resources over Turkey. Especially, there could be significant problems over Euphrates-Tigris basin because of the decreasing water availability in future scenario. Keywords: Climate change, regional climate modeling, downscaling scenarios

New Statistical downscaling methods and applications for Turkey

Hava ve iklim süreçlerinin yeryüzündeki yaşam üzerinde hayati etkileri vardır. İklim değişkenliği ve değişiminin anlaşılabilmesi, bölgesel ve yerel iklim tanılarının geliştirilmesi, iklim çalışmalarının temel konularından biridir. İklim etkilerini araştıranlar genelde iklim değişiminin ve değişkenliğinin geçmişi, bugünü ve geleceği hakkında detaylı ve doğru bilgilere gereksinim duyarlar. İklim değişimi ve değişkenliği konusunda önemli ve temel araçlar genel dolaşım modelleridir (GDM). Ne yazık ki kaba sayısal çözünürlük üzerinde çalıştırılan GDM’ler yerel iklim değişimi ve değişkenliği hakkında doğru bilgi veremezler. Bu bağlamda, GDM’lerin kısıtlarından dolayı “ölçek küçültme” stratejilerinin geliştirilmesine gerek vardır. İklim araştırma ve etkilerinin arasındaki farklı ölçekler; “ölçek küçültme” ve “ölçek büyültme” yaklaşımları ile birbirine bağlanabilir. Bu çalışma, yeni ölçek küçültme yöntemlerini geliştirme ve Türkiye üzerine uygulanması konusunda ilk ve tek araştırmadır. Anahtar Kelimeler: Bölgesel, genel dolaşım modeli, iklim etki, ölçek küçültme, Türkiye, yinelemeli yapay sinir ağları.Weather and climate have a profound influence on life on earth. Understanding climate variability and climate change reveals the increasing need for improving regional and local-scale climate diagnosis which is one of the main goals of climate research. The climate impact researches usually require accurate and detailed climate information on yesterday, present, and tomorrow with high resolution space scale. The main and important tools of studying climate are general circulation models (GCMs). Unfortunately, GCMs running on coarse resolution may not be able to detect the local scale climate variability. The spatial-scale mismatch between climate research and climate impact studies has to be bridged by ?downscaling? on the side of the climate research and ?upscaling? on the side of the climate impact research. This study is the first research of developing downscaling strategies over Turkey. Two new downscaling strategies for climate diagnosis are developed in this study. The proposed methods are based on artificial recurrent neural networks (RNN) and multivariate statistical techniques that derive transfer functions from the large-scale free troposphere variables of which are assumed to govern the local climate over Turkey. This study presents two new approaches for downscaling monthly near-surface air temperature and total precipitation for Turkey stations by surface large-scale pressure systems and upper air circulations derived from National Centers for Environmental Prediction- National Center of Atmospheric Research (NCEP-NCAR) Reanalysis data sets. Keywords: Regional, general circulation model, climate impact, downscaling, Turkey, artificial recurrent neural networks

A Modeling Framework to Frame a Biological Invasion: <i>Impatiens glandulifera</i> in North America

Biological invasions are a major component of global environmental change with severe ecological and economic consequences. Since eradicating biological invaders is costly and even futile in many cases, predicting the areas under risk to take preventive measures is crucial. Impatiens glandulifera is a very aggressive and prolific invasive species and has been expanding its invasive range all across the Northern hemisphere, primarily in Europe. Although it is currently spread in the east and west of North America (in Canada and USA), studies on its fate under climate change are quite limited compared to the vast literature in Europe. Hybrid models, which integrate multiple modeling approaches, are promising tools for making projections to identify the areas under invasion risk. We developed a hybrid and spatially explicit framework by utilizing MaxEnt, one of the most preferred species distribution modeling (SDM) methods, and we developed an agent-based model (ABM) with the statistical language R. We projected the I. glandulifera invasion in North America, for the 2020–2050 period, under the RCP 4.5 scenario. Our results showed a predominant northward progression of the invasive range alongside an aggressive expansion in both currently invaded areas and interior regions. Our projections will provide valuable insights for risk assessment before the potentially irreversible outcomes emerge, considering the severity of the current state of the invasion in Europe

Past, present and future distributions of Oriental beech (Fagus orientalis) under climate change projections.

Species distribution models can help predicting range shifts under climate change. The aim of this study is to investigate the late Quaternary distribution of Oriental beech (Fagus orientalis) and to project future distribution ranges under different climate change scenarios using a combined palaeobotanical, phylogeographic, and modelling approach. Five species distribution modelling algorithms under the R-package `biomod2`were applied to occurrence data of Fagus orientalis to predict distributions under present, past (Last Glacial Maximum, 21 ka, Mid-Holocene, 6 ka), and future climatic conditions with different scenarios obtained from MIROC-ESM and CCSM4 global climate models. Distribution models were compared to palaeobotanical and phylogeographic evidence. Pollen data indicate northern Turkey and the western Caucasus as refugia for Oriental beech during the Last Glacial Maximum. Although pollen records are missing, molecular data point to Last Glacial Maximum refugia in northern Iran. For the mid-Holocene, pollen data support the presence of beech in the study region. Species distribution models predicted present and Last Glacial Maximum distribution of Fagus orientalis moderately well yet underestimated mid-Holocene ranges. Future projections under various climate scenarios indicate northern Iran and the Caucasus region as major refugia for Oriental beech. Combining palaeobotanical, phylogeographic and modelling approaches is useful when making projections about distributions of plants. Palaeobotanical and molecular evidence reject some of the model projections. Nevertheless, the projected range reduction in the Caucasus region and northern Iran highlights their importance as long-term refugia, possibly related to higher humidity, stronger environmental and climatic heterogeneity and strong vertical zonation of the forest vegetation

Mapping ecoregions under climate change: a case study from the biological ‘crossroads’ of three continents, Turkey

ContextBesides climate change vulnerability, most ecosystems are under threat from a history of improper land-use and conservation policies, yet there is little existing long-term ecological research infrastructure in Turkey. In regions with no ecological networks across large landscapes, ecoregion concept offers opportunities for characterizing the landscape under changing climate.ObjectivesAim is to develop contemporary and future quantitative ecoregions for Turkey based on climate model outputs, to identify climate change-sensitive areas of biodiversity and conservation significance, and to provide a framework for a comprehensive ecological observatory network design.MethodsUsing Multivariate Spatio-Temporal Clustering and climate data contemporary and projected future distributions of Turkey’s ecoregions are delineated at several division levels.ResultsTurkey’s contemporary ecoregions generally show a northward shift by the end of this century and the lengthening of the growing season across the country, especially eastward and northward. The increase in growing season length, along with the shift in precipitation seasonality and increasing growing season precipitation, shape future conditions within the climate change-sensitive areas. Apart from transboundary ecological and socioeconomic significance, these potentially vulnerable ecosystems also constitute the majority of Turkey’s biodiversity hotspots.ConclusionsOur study marks the first ‘ecoregionalization’ study for Turkey based on both contemporary and future climate scenarios. For countries like Turkey, where large-scale ecological networks have not been established, using such quantitative methodology for delineation of optimal ecoclimatic regions, and for mapping environments at risk from climate change provides an invaluable perspective for conservation planning strategies, and a framework for a comprehensive ecological observatory network design.</p

Past, present and future distributions of Oriental beech (Fagus orientalis) under climate change projections

Species distribution models can help predicting range shifts under climate change. The aimof this study is to investigate the late Quaternary distribution of Oriental beech (Fagus orientalis)and to project future distribution ranges under different climate change scenarios usinga combined palaeobotanical, phylogeographic, and modelling approach. Five species distributionmodelling algorithms under the R-package ‘biomod2‘were applied to occurrence dataof Fagus orientalis to predict distributions under present, past (Last Glacial Maximum, 21ka, Mid-Holocene, 6 ka), and future climatic conditions with different scenarios obtainedfrom MIROC-ESM and CCSM4 global climate models. Distribution models were comparedto palaeobotanical and phylogeographic evidence. Pollen data indicate northern Turkey andthe western Caucasus as refugia for Oriental beech during the Last Glacial Maximum.Although pollen records are missing, molecular data point to Last Glacial Maximum refugiain northern Iran. For the mid-Holocene, pollen data support the presence of beech in thestudy region. Species distribution models predicted present and Last Glacial Maximum distributionof Fagus orientalis moderately well yet underestimated mid-Holocene ranges.Future projections under various climate scenarios indicate northern Iran and the Caucasusregion as major refugia for Oriental beech. Combining palaeobotanical, phylogeographicand modelling approaches is useful when making projections about distributions of plants.Palaeobotanical and molecular evidence reject some of the model projections. Nevertheless,the projected range reduction in the Caucasus region and northern Iran highlights theirimportance as long-term refugia, possibly related to higher humidity, stronger environmentaland climatic heterogeneity and strong vertical zonation of the forest vegetation

Multi-century spatiotemporal patterns of fire history in black pine forests, Turkey

In this study, we aimed to use tree-ring based fire reconstruction to understand the spatiotemporal patterns of past fires in different climate types of western Anatolia. We collected fire scarred wood samples from living trees as wedges and remnant woods from ten sites along a transect that represents a continental to Mediterranean climate gradient. We determined fire years and assigned seasonality of fires based on the intraring position of the fire scars. We calculated fire statistics and analysed fire-climate relationships. Breakpoints in our Anatolian regional fire chronology were estimated to determine the regime shifts. A decrease in fire frequency was recorded at most of the sites after the end of the 19th and the beginning of the 20th century. We observed two critical fire regime shift periods. The period between 1853 and 1934 is characterized by highly frequent (a total of 82 fires) and simultaneous fires occurring in multiple sites and this period overlapped with the longest and most severe drought period of the past 550 years. The fire frequency decline after 1934 coincided with the period of the first forest protection law in 1937. Dry, as well as prior wet conditions were main drivers of fires in the black pine forests in western Anatolia. We observed a decrease in fire frequency in the late 19th and early 20th centuries due to fire suppression activities. Continued fire suppression activities may cause fuel accumulation and pose a risk for more intense fires and thus a paradox for forests in the future. Based on future climate projections, we will face prolonged fire seasons as a consequence of increasing drought frequency, which may shift the fire regime from surface to crown fires with the accumulation of combustible material in the understory in black pine forests.24 month embargo; available online: 20 May 2022This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Fire history of Pinus nigra in Western Anatolia: A first dendrochronological study

Forests in the Mediterranean basin frequently experience fires due to both anthropogenic and natural causes. There are concerns that the fire season will prolong in the Mediterranean basin, the fire frequency will increase with ongoing climate change, moreover, the fire regimes will shift from surface fires to local crown fires. Here, we aim to improve our understanding of the fire regime components of black pine forests in Turkey by 1) reconstructing a high-resolution fire chronology based on tree rings, 2) revealing the seasonality of fires, 3) investigating the relationship between fire and climate, and 4) comparing our reconstruction results with documentary data from forest management units. We collected 62 fire-scarred trees from three sites in Kütahya and developed a 368 year-long (1652–2019) composite fire chronology using dendrochronological methods. We found that at two sites major fire years coincided with dry years. Two major fire years (1853 and 1879) were common to all sites and two additional fire years (1822 and 1894) were found at two sites. Our results show a sharp decline in fire frequency after the beginning of the 20th century at all sites that can be attributed to increased fire suppression efforts and forest management activities in the 20th century. Our results suggest that the spread of fires has been actively suppressed since the first forest protection law in Turkey. Yet, tree-ring based and documentary data corroboration shows that seasonality did not change over the past +350 years. © 2021 Elsevier GmbH24 month embargo; available online 8 August 2021This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Turkey's globally important biodiversity in crisis

Turkey (Türkiye) lies at the nexus of Europe, the Middle East, Central Asia and Africa. Turkey's location, mountains, and its encirclement by three seas have resulted in high terrestrial, fresh water, and marine biodiversity. Most of Turkey's land area is covered by one of three biodiversity hotspots (Caucasus, Irano-Anatolian, and Mediterranean). Of over 9000 known native vascular plant species, one third are endemic. Turkey faces a significant challenge with regard to biodiversity and associated conservation challenges due to limited research and lack of translation into other languages of existing material. Addressing this gap is increasingly relevant as Turkey's biodiversity faces severe and growing threats, especially from government and business interests. Turkey ranks 140th out of 163 countries in biodiversity and habitat conservation. Millennia of human activities have dramatically changed the original land and sea ecosystems of Anatolia, one of the earliest loci of human civilization. Nevertheless, the greatest threats to biodiversity have occurred since 1950, particularly in the past decade. Although Turkey's total forest area increased by 5.9% since 1973, endemic-rich Mediterranean maquis, grasslands, coastal areas, wetlands, and rivers are disappearing, while overgrazing and rampant erosion degrade steppes and rangelands. The current "developmentalist obsession", particularly regarding water use, threatens to eliminate much of what remains, while forcing large-scale migration from rural areas to the cities. According to current plans, Turkey's rivers and streams will be dammed with almost 4000 dams, diversions, and hydroelectric power plants for power, irrigation, and drinking water by 2023. Unchecked urbanization, dam construction, draining of wetlands, poaching, and excessive irrigation are the most widespread threats to biodiversity. This paper aims to survey what is known about Turkey's biodiversity, to identify the areas where research is needed, and to identify and address the conservation challenges that Turkey faces today. Preserving Turkey's remaining biodiversity will necessitate immediate action, international attention, greater support for Turkey's developing conservation capacity, and the expansion of a nascent Turkish conservation ethic. © 2011