Long-term Climate Trends Research Articles

Bayesian Data Analysis for Revealing Causes of the Middle Pleistocene Transition

Currently, causes of the middle Pleistocene transition (MPT) – the onset of large-amplitude glacial variability with 100 kyr time scale instead of regular 41 kyr cycles before – are a challenging puzzle in Paleoclimatology. Here we show how a Bayesian data analysis based on machine learning approaches can help to reveal the main mechanisms underlying the Pleistocene variability, which most likely explain proxy records and can be used for testing existing theories. We construct a Bayesian data-driven model from benthic δ18O records (LR04 stack) accounting for the main factors which may potentially impact climate of the Pleistocene: internal climate dynamics, gradual trends, variations of insolation, and millennial variability. In contrast to some theories, we uncover that under long-term trends in climate, the strong glacial cycles have appeared due to internal nonlinear oscillations induced by millennial noise. We find that while the orbital Milankovitch forcing does not matter for the MPT onset, the obliquity oscillation phase-locks the climate cycles through the meridional gradient of insolation.

ЭМПИРИЧЕСКОЕ ИССЛЕДОВАНИЕ КРИТИЧЕСКОГО ПЕРЕХОДА В КЛИМАТЕ ПЛЕЙСТОЦЕНА НА ОСНОВЕ НЕЛИНЕЙНОДИНАМИЧЕСКОЙ РЕКОНСТРУКЦИИ

Until now, cause of the Mid-Pleistocene Transition (MPT), when the dominant periodicity of climate cycles changed from 41,000 to 100,000 years in the absence of significant change in orbital forcing, are still an open question in Paleoclimatology. Here we show how a Bayesian data analysis and nonlinear dynamical reconstruction methods can help to reveal the main mechanisms underlying the Pleistocene variability. Our Bayesian data-driven model from benthic d18O records (LR04 stack) accounts the main factors which may potentially impact climate of the Pleistocene: internal climate dynamics, gradual trends, variations of insolation, and millennial variability. In contrast to some theories, we uncover that under long-term trends in climate, the strong glacial cycles have appeared due to internal nonlinear oscillations induced by millennial noise. We find that while the orbital Milankovitch forcing does not matter for the MPT onset, the obliquity oscillation phase-locks the climate cycles through the meridional gradient of insolation. The research was supported by the RAS Presidium Program «Nonlinear dynamics: fundamental problems and applications».

Wildfires and climate change push low-elevation forests across a critical climate threshold for tree regeneration

Climate change is increasing fire activity in the western United States, which has the potential to accelerate climate-induced shifts in vegetation communities. Wildfire can catalyze vegetation change by killing adult trees that could otherwise persist in climate conditions no longer suitable for seedling establishment and survival. Recently documented declines in postfire conifer recruitment in the western United States may be an example of this phenomenon. However, the role of annual climate variation and its interaction with long-term climate trends in driving these changes is poorly resolved. Here we examine the relationship between annual climate and postfire tree regeneration of two dominant, low-elevation conifers (ponderosa pine and Douglas-fir) using annually resolved establishment dates from 2,935 destructively sampled trees from 33 wildfires across four regions in the western United States. We show that regeneration had a nonlinear response to annual climate conditions, with distinct thresholds for recruitment based on vapor pressure deficit, soil moisture, and maximum surface temperature. At dry sites across our study region, seasonal to annual climate conditions over the past 20 years have crossed these thresholds, such that conditions have become increasingly unsuitable for regeneration. High fire severity and low seed availability further reduced the probability of postfire regeneration. Together, our results demonstrate that climate change combined with high severity fire is leading to increasingly fewer opportunities for seedlings to establish after wildfires and may lead to ecosystem transitions in low-elevation ponderosa pine and Douglas-fir forests across the western United States.

The Impact of Climate and Weather on a Small Tourism Business: A wSWOT Case Study

Climatic variability and shifting weather patterns, resulting in extreme weather events and natural disasters, pose risks to small businesses in the United States. This is particularly true in coastal regions of the southeast United States where extreme events such as hurricanes, flooding, and thunderstorms are projected to increase in frequency and intensity. Yet, the vast majority of small business owners do not have a disaster plan in place and an estimated 40% to 60% of small businesses that have experienced a natural disaster never reopen. This teaching case explores the impact of climatic trends and weather on one location of an outdoor tourism industry business in the coastal community of Virginia Beach, Virginia. The case draws from observed weather and sales data for the local small business. Students will draw from descriptive statistics, statistical analysis, and graphs to explore (a) long-term climatic trends for the business; (b) relationships between small business sales and local weather; and (c) strengths, weaknesses, opportunities, and threats relative to weather conditions and climate change. Instructors can give the body of this document to students. They can also make use of the supplemental teaching notes to assist them with teaching this case.

Climate Change and Health: A Historical Analysis of Vivax Malaria Outbreak in Moscow (Russia) during 1999-2008

In the early 1990s vivax malaria resurged in Russia affecting the areas that had been malaria-free since 1960s. In total, at least 525 cases of local transmission were recorded during 1999-2009 in the European part of Russia alone. Moscow region consisting of two member states of Russian Federation, Moscow city and Moscow oblast’, was most seriously affected with 386 autochthonous malaria cases, including 90 within the city of Moscow alone. The sources of infection were mostly labour migrants from Central Asian countries.The aim of this study is to analyze long-term climatic trends in respect to malaria transmission and to identify natural indicators characterizing the risk of vivax malaria reintroduction in a temperate climate using meteorology, remote sensing and geospatial analysis.Using meteorological data from 16 stations located in Moscow region for 1977-2016 we assessed the elements of malaria season by Moshkovsky‘s method. The distribution of malaria cases was analysed using Landsat and Spot 5 satellite imagery. The calculation of different environmental variables (including NDVI, LST, LULC etc.) derived from satellite images was conducted for almost 300 water bodies of Moscow city that had been identified as anopheline breeding places by malaria control programme. As a result, environmental indicators for territory typization in relation to malaria have been selected.An increasing trend of two indicators over the last 40 years has been observed: (1) the sums of effective temperatures (otherwise known as growing degree days, GDDs), and (2) the duration of the season of mosquito’s effective infection. The most pronounced changes relate to the 2000s. Spatial heterogeneity of other indicators and their trends has been observed. An urban heat island of Moscow city affects malaria epidemiological parameters and became more intense during the period under study.

Long-term trends in climate and hydrology in Jinghe River Basin

The Jinghe River Basin lies in the centre of the Loess Plateau in China which is located in the subtropical climate zone. The watershed suffers serious soil erosion, as well as droughts. It is one of the regions with the most severe soil erosion and the most vulnerable ecological environment not only in China but also in the whole world. Linear regression analysis, Mann-Kendall trends and breakpoint analysis were used to detect the changing dynamics of climatic variables and runoff in the basin. The result shows that the temperature and precipitation in the Jinghe River basin have a uniform spatial distribution from 1960 to 2005, and the mean average temperature has shown a significant upward tendency over the years. The average annual rainfall is relatively stable, showing a decreasing trend since the 1970s. Annual runoff over 1973-2003 was a decline with a breakpoint occurred in the 1990s. Understanding the long-term trend in climate and hydrology are crucial for water resource management in semi-arid regions such as the Loess Plateau.

Influence of sampling and disturbance history on climatic sensitivity of temperature-limited conifers

Accurately capturing medium- to low-frequency trends in tree-ring data is vital to assessing climatic response and developing robust reconstructions of past climate. Non-climatic disturbance can affect growth trends in tree-ring-width (RW) series and bias climate information obtained from such records. It is important to develop suitable strategies to ensure the development of chronologies that minimize these medium- to low-frequency biases. By performing high density sampling (760 trees) over a ~40-ha natural high-elevation Norway spruce ( Picea abies) stand in the Romanian Carpathians, this study assessed the suitability of several sampling strategies for developing chronologies with an optimal climate signal for dendroclimatic purposes. There was a roughly equal probability for chronologies (40 samples each) to express a reasonable ( r = 0.3–0.5) to non-existent climate signal. While showing a strong high-frequency response, older/larger trees expressed the weakest overall temperature signal. Although random sampling yielded the most consistent climate signal in all sub-chronologies, the outcome was still sub-optimal. Alternative strategies to optimize the climate signal, including very high replication and principal components analysis, were also unable to minimize this disturbance bias and produce chronologies adequately representing climatic trends, indicating that larger scale disturbances can produce synchronous pervasive disturbance trends that affect a large part of a sampled population. The Curve Intervention Detection (CID) method, used to identify and reduce the influence of disturbance trends in the RW chronologies, considerably improved climate signal representation (from r = 0.28 before correction to r = 0.41 after correction for the full 760 sample chronology over 1909–2009) and represents a potentially important new approach for assessing disturbance impacts on RW chronologies. Blue intensity (BI) also shows promise as a climatically more sensitive variable which, unlike RW, does not appear significantly affected by disturbance. We recommend that studies utilizing RW chronologies to investigate medium- to long-term climatic trends also assess disturbance impact on those series.

Synchronous tropical and polar temperature evolution in the Eocene.

Palaeoclimate reconstructions of periods with warm climates and high atmospheric CO2 concentrations are crucial for developing better projections of future climate change. Deep-ocean1,2 and high-latitude3 palaeotemperature proxies demonstrate that the Eocene epoch (56 to 34 million years ago) encompasses the warmest interval of the past 66 million years, followed by cooling towards the eventual establishment of ice caps on Antarctica. Eocene polar warmth is well established, so the main obstacle in quantifying the evolution of key climate parameters, such as global average temperature change and its polar amplification, is the lack of continuous high-quality tropical temperature reconstructions. Here we present a continuous Eocene equatorial sea surface temperature record, based on biomarker palaeothermometry applied on Atlantic Ocean sediments. We combine this record with the sparse existing data4-6 to construct a 26-million-year multi-proxy, multi-site stack of Eocene tropical climate evolution. We find that tropical and deep-ocean temperatures changed in parallel, under the influence of both long-term climate trends and short-lived events. This is consistent with the hypothesis that greenhouse gas forcing7,8, rather than changes in ocean circulation9,10, was the main driver of Eocene climate. Moreover, we observe a strong linear relationship between tropical and deep-ocean temperatures, which implies a constant polar amplification factor throughout the generally ice-free Eocene. Quantitative comparison with fully coupled climate model simulations indicates that global average temperatures were about 29, 26, 23 and 19 degrees Celsius in the early, early middle, late middle and late Eocene, respectively, compared to the preindustrial temperature of 14.4 degrees Celsius. Finally, combining proxy- and model-based temperature estimates with available CO2 reconstructions8 yields estimates of an Eocene Earth system sensitivity of 0.9 to 2.3 kelvin per watt per square metre at 68 per cent probability, consistent with the high end of previous estimates11.

Trends in Precipitation and Temperatures in Eastern Slovakia (1962–2014)

In this paper, the results of trend analysis applied to precipitation and temperature monthly data for the period from 1962 to 2014 is presented for the hydrological year (from November to October) in sixteen climatic stations in Eastern Slovakia. The topography of this part of the country is very diverse and it affects the climate. The Mann-Kendall non-parametric test coupled with Sen’s slope was applied to identify the significant long-term climatic trends, as well as the magnitude of those trends. According to the present study, all climatic stations in Eastern Slovakia show a positive trend in temperature during the year and almost all of them show a significant positive annual trend in temperature. Seasonal and monthly trend analyses produced the same results. Trends in temperature are always positive during winter and spring. Trends in precipitation are also mostly positive during winter and spring, although some negative trends were also found during these seasons. The spatial distribution of precipitation and temperature trends was modelled in ArcGIS using geostatistical analysis. Abrupt positive trend shifts in annual precipitation and temperature time series were also investigated. An abrupt shift in precipitation at the highest climatic station, Lomnický peak, began around 1985 (+). Abrupt shifts in temperature began around 1970 (+) at the presented climatic stations. The extremity of the climate is confirmed by an analysis of the trends in wet and dry spells. Trends showed increasing tendencies in medium- and long-term wet spells.

Historical fluctuations and recent observations of Northern Anchovy Engraulis mordax in the Salish Sea

Many small pelagic fish species exhibit dramatic fluctuations in abundance accompanied by range expansions during periods of favorable environmental conditions. The location and extent of suitable habitats also shift in response to both short term variability and long term trends in climate. Near the margins of a contemporary range, trends in abundance may reflect a continuation of historical variability but may also foreshadow future changes in distribution. The Salish Sea (all inland marine waters of Washington State and southern British Columbia; made up of the Strait of Georgia, Strait of Juan de Fuca, and Puget Sound) is a highly productive estuarine system at the northern end of the distribution of Northern Anchovy (Engraulis mordax). An apparent recent (2014–2016) increase in Northern Anchovy abundance has generated interest in the dynamics of this species in the Salish Sea. We compiled recent and historical data to understand spatiotemporal patterns of distribution and fluctuations in abundance over the last century. Spatially-consistent occurrence of eggs, larvae, and juveniles, and year-round presence of multiple age classes, confirm that successful spawning and recruitment of Northern Anchovy occurs within the Salish Sea. Most periods of elevated Northern Anchovy abundance in the last century have corresponded to, or lagged, periods of elevated ocean temperatures. While a 2005 peak in abundance within the Salish Sea also corresponded to higher abundance of Northern Anchovy in adjacent regions of the coastal Pacific Ocean, it seems unlikely that Salish Sea abundance is controlled primarily by advection or migration from external populations. Persistence of elevated ocean temperatures like those observed from 2014 to 2016 could lead to consistently high abundance of Northern Anchovy within the Salish Sea, with implications for trophic relationships and ecosystem function.

The palaeodemographic and environmental dynamics of prehistoric Arctic Norway: An overview of human-climate covariation

This paper presents the first palaeodemographic results of a newly assembled region-wide radiocarbon record of the Arctic regions of northern Norway. The dataset contains a comprehensive collection of radiocarbon dates in the area (N = 1205) and spans the 10,000-year period of hunter-gatherer settlement history from 11500 to 1500 cal BP. Utilizing local, high-resolution palaeoclimate data, the paper performs multi-proxy correlation testing of climate and demographic dynamics, looking for hunter-gatherer responses to climate variability. The paper compares both long-term climate trends and short-term disruptive climate events with the demographic development in the region. The results demonstrate marked demographic fluctuations throughout the period, characterized by a general increase, punctuated by three significant boom and bust-cycles centred on 6000, 3800 and 2200 cal BP, interpreted as instances of climate forcing of human demographic responses. The results strongly suggest the North Cape Current as a primary driver in the local environment and supports the patterns of covariance between coastal climate proxies and the palaeodemographic model. A mechanism of climate forcing mediation through marine trophic webs is proposed as a tentative explanation of the observed demographic fluxes, and a comparison with inter-regional results demonstrate remarkable similarity in demographic trends across mid-Holocene north and west Europe. The results of the north Norwegian radiocarbon record are thus consistent with independent, international efforts, corroborating the existing pan-European results and help further substantiate super-regional climate variability as the primary driver of population dynamics regardless of economic adaptation.

Luminescent Solar Concentrator Paintings: Connecting Art and Energy

The increased awareness of greenhouse gas emissions on long-term climate trends has put the spotlight back on the development of renewable energy technologies to mitigate these processes. Solar based electricity generation has gained widespread recognition as a viable source of renewable energy but has been slowed by a number of factors including cost and available application areas. Luminescent solar concentrators (LSC) are being investigated as a low-cost route to expand solar energy harvesting into new spaces. With this demonstration, we develop kits for educating students about renewable and solar energy while promoting a sense of creativity often lacking in STEM demonstrations. Students design LSC devices by painting newly developed luminescent dyes on plastic waveguides. Thin solar cell strips are mounted around the edges of the LSC paintings to generate power. Creativity in design, a central part of scientific discovery and advancement, is promoted throughout the painting and testing of LSC materials.

Perceptions of seasonal weather are linked to beliefs about global climate change: evidence from Norway

As climate change continues to alter local weather patterns, it is important to understand how people are experiencing such changes because personal experience may affect mitigation and adaptation policy preferences and behaviors. Local weather conditions are also an easily accessible source of information that, aggregated over time, may enable people to detect long-term climate trends and update their beliefs about global warming. However, motivated reasoning—the tendency to fit information to conclusions that correspond with a preexisting belief—may limit the accuracy of local weather perceptions. This paper focuses on perceptions of seasonal weather in Norway and examines evidence for motivated reasoning consistent with pre-existing beliefs about climate change, using a national panel survey combined with high-resolution seasonal climate observations. Respondents’ perceptions are sensitive to observed differences in both temperature and precipitation, but respondents are more likely to accurately perceive local precipitation than local temperature. Controlling for observed conditions, beliefs about global climate change had a large effect on perceptions of seasonal temperature, and smaller effects on perceptions of seasonal precipitation. These findings provide evidence that individual perceptions of seasonal weather are related to local conditions, but they are also likely to be motivated by beliefs about global climate change.

Quantitative attribution of climate effects on Hurricane Harvey’s extreme rainfall in Texas

Hurricane Harvey made landfall in August 2017 as the first land-falling category 4 hurricane to hit the state of Texas since Hurricane Carla in September 1961. While its intensity at landfall was notable, most of the vast devastation in the Houston metropolitan area was due to Harvey stalling near the southeast Texas coast over the next several days. Harvey’s long-duration rainfall event was reminiscent of extreme flooding that occurred in the neighboring state of Louisiana: both of which were caused by a stalled tropical low-pressure system producing four days of intense precipitation. A quantitative attribution analysis of Harvey’s rainfall was conducted using a mesoscale atmospheric model forced by constrained boundary and initial conditions that had their long-term climate trends removed. The removal of the various trends of the boundary and initial conditions minimizes the effects of warming in the air and the ocean surface on Harvey. The 60 member ensemble simulations suggest that post-1980 climate warming could have contributed to the extreme precipitation that fell on southeast Texas during 26–29 August 2017 by approximately 20%, with an interquartile range of 13%–37%. While the attribution outcome could be model dependent, this downscaling approach affords the closest means possible of a case-to-case comparison for event attribution, complementing other statistics-based attribution studies on Harvey. Further analysis of a global climate model tracking Harvey-like stalling systems indicates an increase in storm frequency and intensity over southeast Texas through the mid-21st century.

Biodiversity responds to increasing climatic extremes in a biome-specific manner

An unprecedented rate of global environmental change is predicted for the next century. The response to this change by ecosystems around the world is highly uncertain. To address this uncertainty, it is critical to understand the potential drivers and mechanisms of change in order to develop more reliable predictions. Australia's Long Term Ecological Research Network (LTERN) has brought together some of the longest running (10–60years) continuous environmental monitoring programs in the southern hemisphere. Here, we compare climatic variables recorded at five LTERN plot network sites during their period of operation and place them into the context of long-term climatic trends. Then, using our unique Australian long-term datasets (total 117 survey years across four biomes), we synthesize results from a series of case studies to test two hypotheses: 1) extreme weather events for each plot network have increased over the last decade, and; 2) trends in biodiversity will be associated with recent climate change, either directly or indirectly through climate-mediated disturbance (wildfire) responses. We examined the biodiversity responses to environmental change for evidence of non-linear behavior. In line with hypothesis 1), an increase in extreme climate events occurred within the last decade for each plot network. For hypothesis 2), climate, wildfire, or both were correlated with biodiversity responses at each plot network, but there was no evidence of non-linear change. However, the influence of climate or fire was context-specific. Biodiversity responded to recent climate change either directly or indirectly as a consequence of changes in fire regimes or climate-mediated fire responses. A national long-term monitoring framework allowed us to find contrasting species abundance or community responses to climate and disturbance across four of the major biomes of Australia, highlighting the need to establish and resource long-term monitoring programs across representative ecosystem types, which are likely to show context-specific responses.

Active carbon sequestration in the Alpine mantle wedge and implications for long-term climate trends

The long-term carbon budget has major implications for Earth’s climate and biosphere, but the balance between carbon sequestration during subduction, and outgassing by volcanism is still poorly known. Although carbon-rich fluid inclusions and minerals are described in exhumed mantle rocks and xenoliths, compelling geophysical evidence of large-scale carbon storage in the upper mantle is still lacking. Here, we use a geophysical surface-wave seismic tomography model of the mantle wedge above the subducted European slab to document a prominent shear-wave low-velocity anomaly at depths greater than 180 km. We propose that this anomaly is generated by extraction of carbonate-rich melts from the asthenosphere, favoured by the breakdown of slab carbonates and hydrous minerals after cold subduction. The resulting transient network of carbon-rich melts is frozen in the mantle wedge without producing volcanism. Our results provide the first in-situ observational evidence of ongoing carbon sequestration in the upper mantle at a plate-tectonic scale. We infer that carbon sequestered during cold subduction may partly counterbalance carbon outgassed from ridges and oceanic islands. However, subducted carbon may be rapidly released during continental rifting, with global effects on long-term climate trends and the habitability of planet Earth.

Analysis of rainfall and temperature time series to detect long-term climatic trends and variability over semi-arid Botswana

Arid and semi-arid environments have been identified with locations prone to impacts of climate variability and change. Investigating long-term trends is one way of tracing climate change impacts. This study investigates variability through annual and seasonal meteorological time series. Possible inhomogeneities and years of intervention are analysed using four absolute homogeneity tests. Trends in the climatic variables were determined using Mann–Kendall and Sen’s Slope estimator statistics. Association of El Niño Southern Oscillation (ENSO) with local climate is also investigated through multivariate analysis. Results from the study show that rainfall time series are fully homogeneous with 78.6 and 50% of the stations for maximum and minimum temperature, respectively, showing homogeneity. Trends also indicate a general decrease of 5.8, 7.4 and 18.1% in annual, summer and winter rainfall, respectively. Warming trends are observed in annual and winter temperature at 0.3 and 1.5% for maximum temperature and 1.7 and 6.5% for minimum temperature, respectively. Rainfall reported a positive correlation with Southern Oscillation Index (SOI) and at the same time negative association with Sea Surface Temperatures (SSTs). Strong relationships between SSTs and maximum temperature are observed during the El Niño and La Niña years. These study findings could facilitate planning and management of agricultural and water resources in Botswana.

Location factors and spatial dependence in household perceptions and adaptations to climate change: A case in the upper Blue Nile Basin

ABSTRACTStudies on perceptions of, and adaptation responses to, climate change have not paid sufficient attention to location and neighbourhood effects. Moreover, although one often regards perceptions as preconditions for adaptation, some direct and underlying factors may influence perceptions and adaptations in opposite ways. To assess determinants of perceived directions of climate change and adaptations by farmers, the paper formulates ordered response and multinomial choice models accounting for the location and neighbourhood effects. Relative to a survey of rural households in the Ethiopian Nile basin, perceptions of long-term climate trends are found to substantially vary across regions, altitudes, distances from markets, and neighbourhood characteristics, with climate reference scales being themselves non-uniform across respondents. The inclusion of proxies for local spatial dependence and clustering in multinomial logit regressions on adaptation decisions provides further insights, relative to individual- and farm-specific features. Adaptation measures turn out to be largely independent from degree of awareness of negative trends in climate changes. This highlights the importance of adaptive strategies coordinated at regional and national scale, such as preventive measures of control of pest damage risk due to increasing temperatures, and specific interventions for semi-arid agro-climatic zones.

The steady enhancement of the Australian Summer Monsoon in the last 200 years

A new bicentennial series of the Australian monsoon strength based on historical wind observations has allowed for the assessment of the variability of this system since the early 19th century. Our series covers a period in which the scarcity of meteorological observations in the area had precluded the evaluation of long-term climatic trends. Results indicate that the increase in precipitation over Northern Australia reported for the last 60 years is just a manifestation of a much longer lasting trend related to the strengthening of the Australian monsoon that has been occurring since at least 1816.

Climatic and human impact on the environment?: A question of scale

The environmental context of cultural transformation’ - frames the central issue of this paper – how were Neolithic and Chalcolithic landscapes in the Aegean, Balkan and Carpathian (ABC) zones shaped and transformed by climatic and anthropogenic impacts? The difficulties in interpreting proxy records for the middle, transitional stage of the Holocene aridification sequence, falling between the early wet stage and the late arid stage, have been created by the conjoint influence of two kinds of impact – climatic and anthropogenic. An unhelpful influence in this debate stems from Willis and Bennett's (1994) hypothesis of minimal human impact on the pre-Bronze Age landscapes of South East Europe. In this paper, two questions are posed: (1) what were the effects of the claimed global changes in Holocene climate at the regional and local scale in the ABC zones?; and (2) can we recognise human impact in these proxy records prior to the Bronze Age of our study regions? Following a discussion of general long-term climatic trends and RCCs (episodes of rapid climatic change), I base a discussion of the so-called 8200BP ‘event’ and pre-Bronze Age human impacts on a suite of 24 well-dated proxy records – mostly pollen sequences. The principal findings are that there is little evidence for impact from the 8200BP ‘event’ in these records, while there is substantial evidence for pre-Bronze Age human impacts on the landscapes of the Aegean, Balkan and Carpathian regions.