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Quaternary International 303 (2013) 64e72

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Quaternary International

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Climatic interpretation of carbon isotope content of mid-Holocenearchaeological charcoals from eastern Anatolia

Alessia Masi a, Laura Sadori a,*, Giovanni Zanchetta b, Ilaria Baneschi c, Marco Giardini a

aDipartimento di Biologia Ambientale, Università di Roma “La Sapienza”, Piazzale Aldo Moro 5, Roma, ItalybDipartimento di Scienze della Terra, Università di Pisa, Via S. Maria 53, Pisa, Italyc Istituto di Geoscienze e Georisorse, CNR, Via Moruzzi, Pisa, Italy

a r t i c l e i n f o

Article history:Available online 17 November 2012

* Corresponding author.E-mail addresses: alessia.masi@uniroma1.it (A. Ma

(L. Sadori), zanchetta@dst.unipi.it (G. Zanchetta), i.ban

1040-6182/$ e see front matter � 2012 Elsevier Ltd ahttp://dx.doi.org/10.1016/j.quaint.2012.11.010

a b s t r a c t

The 13C/12C ratio of juniper charcoals from the archaeological site of Arslantepe, Malatya (Turkey) wasanalysed for the mid-Holocene period spanning from 3350 to 2000 years BC. In addition, modern juniperand deciduous oak specimens were collected during a botanical survey around Arslantepe in August2008. After the evaluation of weather parameters, the modern 13C/12C ratio was compared with thearchaeological one, to infer past seasonal precipitation relative magnitude patterns. D13C values obtainedfrom these samples suggest that the present-day climate is, on average, drier than that recorded in thepast.

Comparing the D13C juniper record with the already published curve for archaeological charcoals ofdeciduous oaks from Arslantepe, it appears that the two curves show similar trends in the short periodbetween ca. 2850 and 2500 BC, in which the curves are substantially parallel and the D13C differencebetween them is quite reduced, but they are shifted by ca. 50e150 years in the rest of the record.

For the interpretation of the arboreal curves, however, it was necessary to consider the autoecology ofmodern plants and the source of the water used for photosynthesis, as the two selected trees show D13Ccurves with rather different patterns. Overall, 13C/12C contrasting ratios in juniper and deciduous oakssuggest that seasonality in rainfall distribution and aquifer recharge played a complex role. Thus,a consistent seasonal contrast in precipitation (similar to the one in recent times) took place at ca. 3350,3100, and 2300 BC indicating that semi-arid conditions have occurred in the past, in alternation withperiods characterised by minor differences in the distribution of annual precipitation. In particular, theperiod between ca. 2850 and 2500 BC may suggest more humid conditions in late winter/early spring.The combination of the two records suggests that 1) two periods of drought are found at ca. 3350e3100and at ca. 2300e2200 BC and 2) that at present winter precipitation is lower than that recorded duringthe period 3350e2000 BC and summer aridity less or equal to that recorded ca. 2200 BC.

Changes in precipitation seasonality and the complex and the peculiar hydrogeological situationhindered the interpretation of the isotope records. The use of two taxa having different autoecology anddifferent growing season allows interpretation of the data in terms of changes in precipitation season-ality and of specific habitat in this complex and peculiar hydrological setting.

� 2012 Elsevier Ltd and INQUA. All rights reserved.

1. Introduction

Past vegetation and climate history of the Holocene can bestudied using natural (e.g. lacustrine sediments) and anthropogenic(archaeological layers) archives (Mercuri et al., 2010, 2011; Sadoriet al., 2010b; Roberts et al., 2011a, 2011b). Interactions betweenenvironmental changes and cultural development are complex,

si), laura.sadori@uniroma1.iteschi@igg.cnr.it (I. Baneschi).

nd INQUA. All rights reserved.

probably due to different agents, whose roles are difficult to clearlyseparate (Diamond, 2005; Sadori et al., 2010a; Mercuri et al., 2011;Sadori et al., 2011; Roberts et al., 2011a).

In the Mediterranean region, precipitation is the most signifi-cant climate factor impacting ecosystems and limiting crop yields,and the combined effect of current aridity with future climatechanges is expected to particularly threaten also the forestecosystems of the area (IPCC, 2012). In this context, studying plantresponses to past global changes provides valuable insights forpredicting future responses to a rapidly changing environment. Inparticular, one key to understand long-term plant responses to

A. Masi et al. / Quaternary International 303 (2013) 64e72 65

climate changes in the Mediterranean area is to characterize pastchanges in precipitation in terms of total amount and annualdistribution and their effects on forest trees. Although globalclimate trends during the Holocene are well described, there isa lack of information on spatial variability. In this framework,charcoal data obtained by archaeological settlements could provideimportant information on the exploitation of the surroundingvegetation and are fundamental in the interpretation of theeconomic history of the site and of environmental changes of itssurroundings (Asouti and Hather, 2001; Asouti and Austin, 2005;Sadori et al., 2008; Alvaro et al., 2010).

A new opportunity in palaeoenvironmental research comesfrom the isotopic analysis from plant macroremains found inarchaeological sites (e.g. Araus et al., 1997a, 1997b, 2003; Ferrioet al., 2005; Aguilera et al., 2008; Fiorentino et al., 2008; Hallet al., 2008; Riehl, 2008; Riehl et al., 2008; Baneschi et al., 2012).In particular, the possibility to reconstruct past climate is based onthe fact that the carbon isotope value of plant remains is verysensitive to drought (e.g. Farquhar et al., 1989). More specifically,13C/12C ratio of plants is a sensitive tracer of the way in which theCO2 and water have been archived in the plant, and provide valu-able environmental information (McCarroll and Loader, 2004).Farquhar et al. (1989) described a positive correlation betweenstable carbon isotope discrimination in plant tissues and theenvironmental parameters of rainfall, temperature and irradiance.Others have found that in C3 plants water availability (air humidityand soil moisture) influences the d13C values (Ehleringer, 1989,1993; Ehleringer and Dawson, 1992; Ehleringer et al., 1992; Araus

Fig. 1. a) In the foreground the archaeological site of Arslantepe, in the background the fertil(A) and of the sites of modern plant collection (number 1e5). c) Hydrogeological map (Marc2012, modified).

et al., 1997a; Edwards et al., 2000; Miller et al., 2001; Warrenet al., 2001; Chen et al., 2005). As a reaction to water stress,photosynthesis is reduced by stomatal closure, protecting vegeta-tive tissues from dehydration and thus changing carbon fixation.

However, the extraction of paleoclimatic information from thecarbon isotope composition of charcoals collected in archaeologicalstrata is not necessarily so straightforward. Archaeological depositsare usually formed during a certain period of time, possiblyrecording some differences in environmental conditions. So, itwould be important to evaluate the variability of 13C/12C ratio foreach archaeological period inferred by the same plant taxon.Although studies of isotopic content in archaeobotanical remainsand their responses to climate have resulted in rapid progress inrecent years, there has been little investigation of the differences inresponses of different taxa collected in the same archaeologicallayers. We want to check the possibility that different taxa yieldcomplementary information allowing a more detailed paleo-climatic reconstruction (Aguilera et al., 2012).

This study presents stable carbon analysis of charcoal remains ofJuniperus spp. coming from the archaeological site of Arslantepe,eastern Turkey (Fig. 1). The isotopic variability during ca. 1350 years(3350e2000 BC) is interpreted as climate variations, comparing theresults with the already published (Masi et al., 2012) isotopic curveobtained from deciduous Quercus from the same site. In theMediterranean basin, the present-day coexistence of junipersand deciduous oaks occurs under varying distribution of annualprecipitation accompanied by an important incidence of summerdrought. Estimation of past climate conditions uses present

e plain of Malatya and the surrounding arid hills. b) Geographical location of Arslantepeolongo and Palmieri, 1983, modified). d) Climate graph for the Malatya area (Masi et al.,

A. Masi et al. / Quaternary International 303 (2013) 64e7266

associations between seasonal precipitation and 13C/12C ratio, byanalysing some specimens of modern juniper and deciduous oakscollected in 2008 in several locations near the site.

2. The study site and its region

2.1. Site

Arslantepe is a tell (an archaeological mound, named tepe inTurkish) located north of the Anti-Taurus range, 6 km north of thecity of Malatya (941 m a.s.l.), in the homonymous plain (Fig. 1). Ithas been under systematic excavation since 1961, by the team ofthe University of Rome “La Sapienza” (http://w3.uniroma1.it/arslantepe). The mound is approximately 15 km west of theEuphrates River and has been occupied at least from the 5thMillennium BC to the end of the Neo-Hittite period (8th cent. BC)(Frangipane, 2004). An approximately 30 m thick anthropogenicdeposit records the long and complex stratigraphy of the mound,which uncovers the continuity of occupation and the alternatingcultural and political relations of the region. Late Chalcolithic 5 andEarly Bronze Age levels are grouped within “Period VI”, with fourmain sub-divisions from A to D.

The VI A period (3350e3000 BC, Late Chalcolithic 5) is animportant documentation of the emergence of the first states. Thesettlement is characterised by a “palace”, a complex of monumentalpublic buildings in which economic, religious and administrativeactivities were performed (Frangipane and Palmieri, 1983). Thedestruction of the palace was followed by phases of alternatingeconomic and political organisations, herders and agriculturalists,foreign and local, at the site. It was completely destroyed bya violent fire at ca. 3000 BC. The whole third millennium BC ischaracterised by a continuous occupation of superimposed villages,fortified and more permanent in VI B2 and VI D periods, moreseasonal and ephemeral during VI B1 period. The VI B1 and VI B2correspondwith Early Bronze Age I (respectively dated at ca. 3000e2900 and 2900e2800 BC).

The VI B1 period is characterised by small and simple privatedwellings, constituted by huts and fences for herding. The simplevillage had a very short life (about one century) and was destroyedby a fire. During the VI B2 period, the village was well structuredand protected by a large wall.

At the end of VI C period, corresponding to Early Bronze Age II(ca. 2750e2500 BC), a violent fire destroyed a house, preservingmany plant macro-remains by charring them (Sadori et al., 2006).

The last analysed period, the VI D, was the most long-livedvillage, lasting about 500 years, therefore the settlement wascomplex. The houses were on terraces adjacent to the hill slopes.

2.2. Environmental setting

According to the hydrogeological and geomorphological studiesperformed by Marcolongo and Palmieri (1983) Arslantepe musthave enjoyed a special position in the Malatya plain (Fig. 1c). In thedirect vicinity of the site, two ground-water systems merge: thefirst from the karst developed on the carbonate hills borderingthe Malatya plain to the south and south-east, the second from theGelincik Tepe volcanic complex to the east of Arslantepe. Thisrepresents a vast hydrogeological catchment, far larger than thehydrographical basin.

The presence of numerous springs both in the plain and nearthe mound favours hygropilous and hydrophilous arborealvegetation (poplars, willows, elms and ashes). This naturallywatered soil allows the intensive cultivation of apricot trees inthe plain so that now there are few remnants of natural vege-tation. The south-eastern Turkish province of Malatya is ca.

100 km east of the Anatolian Diagonal (Davis, 1971), a famoushotspot for biodiversity. This Anatolian province is included inthe Irano-Turanian phytogeographical region (Davis, 1965e1985)and is the richest of Turkey in endemic taxa (Bulut and Yilmaz,2010). Among the endemic taxa of the province are species likeHypericum malatyanum Pesmen and Lotus malatayicus Poinert,whose names reveal their geographic origin. Various floristic studieshave been carried out in the Malatya province in the last twodecades (e.g. Yildiz and Aktoklu, 1996a, 1996b; Yildiz et al., 2004). Inthe region of Malatya, steppe vegetation is dominant. However, insome areas Quercus shrubs are common. Among Quercus species areQuercus infectoria Olivier subsp. boissieri (Reuter) O. Schwarz,Quercus cerris L. var. cerris, Quercus brantii Lindl., Quercus libaniOlivier, often accompanied by many shrubs of rosaceans, mainlyascribed to species of Crataegus, Rosa, Prunus, Pyrus and Cotoneaster.Gymnosperms are very rare, and represented almost exclusively bysome Juniperus species, the most common of which is Juniperusoxycedrus L. subsp. oxycedrus (Yildiz et al., 2004).

In the Malatya area, the diurnal temperature range is high andthe annual average temperature is between 10 and 14 �C. The meanannual precipitation of the Malatya plain is low, about 400 mm,most of which is snow. Winter/early spring precipitation (largelyconsisting of snow) is probably responsible for the level of theaquifers and of spring recharge. The climate is a semi-arid one,while in the adjacent TaurusMountains, where higher precipitation(between 600 and 1000 mm/y) is recorded, it is sub-humid (Atalay,2004; Sensoy et al., 2008). This precipitation largely contributes torecharge the aquifer feeding the springs of the Malatya plain.

Climate data of the Arslantepe surroundings are reported inFig. 1d. The graph shows mean annual values of temperature andmedian values of precipitation obtained for the year 2008 and forthe period 1961e90. The average annual precipitation calculatedfor 2008 is 350 mm/y and the mean temperature is 10.8 �C (Masiet al., 2012).

3. Materials and methods

3.1. Samples

For this study, plant macroremains from four occupationperiods, VI A, VI B2, VI C and VI D, were selected. In particular,charcoal fragments of Juniperus spp. were recovered from all thephases of the human occupation with the exception of the VI B1period. The wood remains were preserved by charring. Flotation ofthe archaeological soil was not practicable because the charcoalsare damaged or even dissolved if soaked in water. Therefore, plantmaterial was hand-separated.

In particular, 22 samples of juniper (Juniperus spp.) charcoalswere analysed. They were mostly collected in closed archaeologicalcontexts clearly related to occupational phases of the site. Theanatomical features of juniper wood do not allow a determinationat the species level (Greguss, 1955; Schweingruber, 1990).

As radiocarbon dating of each plant fragment was not realistic(and the error in the method often causes overlapping in narrowtemporary scales), the archaeological stratigraphic chronology(based on more than one hundred of radiocarbon dates, e.g. Alessioet al., 1983; Calderoni et al., 1994; Kuniholm, 1996; Alvaro et al.,2010) available for each period was used. For single phases insideeach period, a stratigraphic criterion was used, assigning to each ofthem an average date.

For comparison with carbon isotope composition of the char-coals, modern samples were collected during a botanical surveyaround Arslantepe in August 2008. Arboreal plants are nowadaysvery rare around Arslantepe, and only five sites with thickets(Fig.1b) were found at a distance range between 17 and 64 km from

A. Masi et al. / Quaternary International 303 (2013) 64e72 67

the archaeological site. Juniper shrubs are very rare and were found(Table 1) only in three stations. Only one-year-old branches ofjunipers were collected. Four specimens were analyzed (one fromstations 3 and 5 and two from station 4).

Table 1Malatya area. Summary of the five stations’ (for location see Fig. 1b) features and related d13C and D13C values for the modern branch samples of Juniperus and deciduousQuercus (the asterisk marks the data from Masi et al., 2012).

Station Altitude(m a.s.l.)

Distance fromArslantepe (km)

Slope exposure Taxon Specimen d13C &PDB St. dev. Min Max D13C &

1 1100 22 North/East dec. Quercus a �26.0* 0.2 �26.1 �25.8 18.0b �26.2* 0.3 �26.4 �26.0 18.2

2 1350 41 North/East dec. Quercus a �27.4* 0.5 �27.7 �27.0 19.43 1750 64 West dec. Quercus a �26.7* 18.7

b �24.8* 16.8Juniperus cf. sabina L. a �22.0 0.5 �22.3 �21.6 14.0

4 1500 17 West dec. Quercus a �26.6* 18.6b �26.2* 18.2

J. excelsa Bieb. a �22.2 0.1 �22.3 �22.1 14.1J. oxycedrus L. subsp. oxycedrus b �25.0 0.7 �25.6 �24.3 17.0

5 1200 42 North/West dec. Quercus a �25.9* 17.9b �25.3* 17.3

J. oxycedrus L. subsp. oxycedrus a �24.0 0.6 �24.4 �23.6 16.0

Table 2Arslantepe (Malatya). d13C and D13C values of archaeological samples groupedaccording to the archaeological stratigraphy. The letter A (area) and a progressivenumber labels each single recognized archaeological unit.

Period (years BC) Area Sample d13C &PDB St. dev. D13C &

VI D (2500e2000) A1080 2141 �22.1 0.1 16.0A818 1676 �22.7 0.2 16.7A565 652/2 �21.2 0.1 15.1

653 �21.5 0.0 15.4A516 1810 �21.9 0.1 15.8

VI C (2800e2500) A607 931/2 �23.9 0.2 18.0939/1 �23.5 0.2 17.6939/2 �23.6 0.2 17.7939/3 �23.2 0.1 17.3969 �23.7 0.1 17.8

VI B2 (2900e2800) A342 82 �23.4 0.2 17.5A738 1143 �23.5 17.6

VI A (3350e3000) A340 2119 �22.0 16.12120 �21.6 16.0

A365 2126 �22.2 16.32128 �22.5 16.6

A364 5 �21.7 15.8A127 2107 �22.9 17.0A805 1290 �21.2 15.3

1291 �22.3 0.3 16.4A800 1252 �23.0 17.1

1277b �21.7 15.7

3.2. Analytical methods

For the carbon isotope analysis, the archaeological samples wereground into a homogeneous powder in an agate mortar, aftera careful cleaning carried out with a scalpel. Each sample iscomposed of a single charred wood fragment. In the cases in whichthe morphology of the wood samples allowed recognition of youngbranches, these were selected for analysis.

The modern samples were dried, and single, small leaf andbranch fragments were carefully selected. Pre-treatments to extractcellulose were not performed, following the suggestion of Loaderet al. (2003), which indicate that the whole wood preserves thebest climate signal.

The measurements of the 13C/12C ratio were performed bycombustion in an Elemental Analyzer (Carlo Erba, EA1108) coupledwith an isotope ratio mass spectrometer (Delta plus XP Finnigan)via the Finnigan MAT Conflo II interface at the Stable IsotopeLaboratory of IGG-CNR of Pisa, calibrated using a within-run labo-ratory standard (graphite and ANU-sucrose). The results areexpressed using the d-& notation

d13C ¼

2666664

13C

12Csample�

13C12Creference

!

13C12Creference

3777775� 1000

Isotope ratios were expressed as per mille deviations using thed notation relative to the VPDB standard. The analytical repro-ducibility and accuracy on standards were better than 0.1&. Theprecision for replicates of single charcoal is usually better than0.2& (Table 2). For fresh samples, the variability of 13C/12C ratiofor small branch fragments was within 0.3&. Many authors haveconsidered the effects of charring on isotopic composition inplants (e.g. De Niro and Hastorf, 1985; Hall et al., 2008; Aguileraet al., 2012). An experiment at 350 and 450 �C did not revealsignificant differences between fresh and charred samples.

Considering that natural and anthropogenic fires preservingcharcoals never reach the above-mentioned temperatures,a correction factor was not used, according to Steinbeiss et al.(2006) and Hall et al. (2008).

Because carbon isotope fractionation between CO2 and plantduring photosynthesis is influenced by CO2, partial pressure andisotopic composition of air CO2, which are variable during time, toperform comparisons between fossils and living plants, the carbonisotope discrimination (D13C) was calculated according to Farquharet al. (1980):

D13C ¼ d13Cair � d13Csample 1þ d13Csample

1000

!

where d13Csample is the isotopic value of samples and d13Cair is theisotopic value of the atmospheric CO2 in a specific period of time.

A. Masi et al. / Quaternary International 303 (2013) 64e7268

The isotopic value of the atmospheric CO2 and its partial pressurewere obtained from the Antarctic ice core records that provide themost record of air d13C changes (Leuenberger et al., 1992;Indermühle et al., 1999; Eyer et al., 2004). The uncertainty on D13Cvalue estimated by error propagation, considering the standarddeviation of d13Csample and d13Cair is not significantly different fromthe standard deviation of d13Csample.

Fig. 3. Arslantepe (Malatya). D13C values for the archaeological charcoals of Juniperusspp. ordered according to the archaeological chronology of the areas (see Table 2).

4. Results

4.1. d13C in modern samples

The isotopic values for freshwood of junipers branches collectedaround Arslantepe (Fig. 1b) are shown in Table 1 and Fig. 2, togetherwith the results of deciduous Quercus (already published in Masiet al., 2012). Four specimens of different juniper species (Table 1)were analysed. The wood D13C values range from 14.0& to 16.0&with an average of 15.2 � 1.1&. The D13C of deciduous oaks woodranges from 17.6& to 19.4&, with an average of 18.3 � 0.7& and(Masi et al., 2012). The difference between average values of Juni-perus and deciduous Quercus is 3.1&, in agreement with the ex-pected differences between conifers and angiosperms that indicatehigher values for conifers compared to angiosperms (e.g. Leavittand Newberry, 1992; Hemming et al., 1998; Leavitt, 2002;McCarroll and Loader, 2004).

4.2. d13C in archaeological samples

The results of isotopic values for archaeological wood are listedin Table 2 and Fig. 3 in chronological order according to thearchaeological stratigraphy. The isotope analysis was performed on22 samples belonging to 13 different areas of the archaeologicalsite. Isotope values of each area are shown in chronological order inFig. 3, and for the samples that havemore than one value, the meanvalue and the standard deviation are plotted.

The period VI A is divided into three subsequent phases. Theoldest phase samples are from beams of two areas (A800 and A805)at the entrance of the temple B main room, the core of the palatialcomplex. For juniper timber of A800 a dendrochronological date of

Fig. 2. Malatya area. D13C values for the modern branch samples of Juniperus (opencircles) and deciduous Quercus (solid circles; for the latter see also Masi et al., 2012).For sample locations, see Fig. 1.

3374 � 30 BC (2s) is available (Kuniholm, 1996). The average D13Cvalue of this phase is 16.1 � 0.8&. The successive samples are fromA127 and show an average value slightly higher (17.0&). The last VIA phase grouped the samples collected from the areas A364, A365and A340 and is characterized by a mean value very similar to thatof the first phase (16.1 � 0.4&). The VI B period consists of twocompletely different settlements very close in time. Unfortunately,juniper charcoals from VI B1 have not been found. The VI B2 periodis divided in two phases, each providing only one sample. Theoldest area, A738, gave a mean D13C value of 17.6&, the other17.5&. The VI B2 samples show higher values compared with theprevious phases. The data of juniper available for the VI C periodwere obtained only from the A607 charcoal assemblage. The fivesamples analysed provide similar values, with a mean D13C of17.7 � 0.3&. Lastly, the VI D is a long-lasting and complex period.Some analysed samples come from the VI D2 phase in which twoareas were analysed (A516 and A565). Their mean D13C value is15.5 � 0.3&. This value is quite different from the following D13Cone (16.7&) found for A818, which belongs to the VI D2/3 phase.The last value available comes from the VI D3 period (A1080,16.0&) and appears to be similar to the VI D2 data.

5. Discussion

In Fig. 4a the average D13C value for present-day juniper speci-mens collected in 2008 when a mean annual precipitation of350 mmwas recorded, is always lower than the mean fossil record.Although other parameters, such as temperature and irradiance caninterfere with D13C values, past precipitation was higher thanpresent during the vegetative period of juniper. Juniper recordslower D13C values than deciduous oaks (Table 1, Fig. 2). This patternconfirms that in the literature about anatomical and physiologicaldifferences existing between conifers and angiosperms, especiallyif the latter have porous ringwood (e.g. Leavitt and Newberry,1992;Hemming et al., 1998; Leavitt, 2002; McCarroll and Loader, 2004).

Available records from archaeological charcoals confirm thatconifer wood always shows lower values than angiosperms (e.g.Aguilera et al., 2011, 2012). Different taxa show comparableevolution in the carbon isotope composition. In particular, the two

Fig. 4. Arslantepe (Malatya). a) D13C curves for Juniperus (rhomb symbols, this paper) and deciduous Quercus (square symbols, Masi et al., 2012). The dark grey line is present-dayvalue of deciduous Quercus, the light grey line is present-day value of Juniperus. b) d18O curve of Eski Acıgöl lake (Roberts et al., 2001, 2008). c) d18O curve of Soreq cave speleothem(Bar-Matthews and Ayalon, 2011). d) d13C curve of Soreq cave speleothem (Bar-Matthews and Ayalon, 2011). e) d18O curve of Lake Van sediments (Wick et al., 2003). All curves aresimplified.

A. Masi et al. / Quaternary International 303 (2013) 64e72 69

taxa (a pine of Pinus pinea group, probably Pinus halepensis, and anevergreen oak, probably Quercus ilex) selected by Aguilera et al.(2012) show curves with similar trends in the investigated period(5000 BCe600 AD). The authors performed isotope carbon analysison many archaeologically dated sites from the same region(Valencia province, Spain), obtaining curves there were oftenparallel.

According to these data, similar behaviour would be expected inthe curves obtained from the Arslantepe archaeological record,because the area of wood exploitation should have been ratherrestricted and had rather similar environmental conditions (Sadoriet al., 2008). However, the two curves of juniper and deciduousoaks from Arslantepe do not show similar trends, except in theshort period between ca. 2850 and 2500 BC inwhich the curves aremarkedly parallel and the D13C difference between them is reducedto ca. 1& (Fig. 4a). As the sampling contexts and related ages arereliable, at least two explanations could be advanced for thesedifferent behaviors of the two arboreal plants.

Firstly is the possibility that these two different behaviors couldindicate seasonality changes. Aguilera et al. (2012), in their study onpine and evergreen oak, a conifer and an angiosperm, found thatthey provide complementary seasonal records (SeptembereDecember and JanuaryeAugust for pines and oaks, respectively).Therefore, the possibility that deciduous oaks and juniper fromArslantepe record seasonal changes has to be taken into account. Inparticular, they could record different patterns of seasonal precip-itation, nowadays mainly distributed between March and June inthe Malatya plain, with a maximum in May (Fig. 1d).

The maximum difference between juniper and oaks, possiblysuggesting a seasonal contrast, is found at ca. 3100 BC; this may

have occurred at ca. 2300 BC, when isotopic data are close to themodern situation. This pattern outlines a climate similar to thepresent-day one (Fig. 1d), with a marked contrast in seasonalprecipitation, but also points out that current conditions are quitedrier in comparisonwithmost of the archaeological record. On theother hand, the period between ca. 2850 and 2500 BC, when theisotopic differences between the two taxa are reduced, couldrepresent a phase in which a pattern of annual precipitationdifferent from today is recorded: juniper records maximumvaluesof humidity, while deciduous oaks seem to show less wateravailability. Modern data indicate that the juniper vegetativeseason is recorded at the end of the winter/beginning of thespring, while deciduous oaks buds sprout in mid-spring. Theapproaching curves possibly indicate that in the period between2850 and 2500 BC more water was available during late winter/early spring and less during mid-spring. Embracing this inter-pretation infers marked changes in seasonality during the firsthalf of 3rd millennium BC.

The autoecology of the two considered taxa is of paramountimportance to provide another possible interpretation of thedivergent trends. According to Valentini et al. (1992), the hydrogenisotope ratio (dD) of xylem sap, particularly valuable for deter-mining the utilization of specific water resources of living junipers,indicates that this conifer mainly uses rain-water, while deciduousoaks mainly use ground-water. The vegetative recover of junipersoccurs early in the year, when snow precipitation is recorded in theMalatya area. The relatively short period of growth of deciduousoaks coincides with the driest months of the year (Fig. 1d). Theytherefore depend more on a constant source of water such as thatcoming from water-bearing strata (Valentini et al., 1992).

A. Masi et al. / Quaternary International 303 (2013) 64e7270

The peculiar conformation of the Arslantepe substratum helpsto explain the deep differences existing between the water avail-able from precipitation and that from groundwater. Numeroussprings gush fairly abundantly and continuously at the foot of thehill. The Malatya plain, even if located in a semi-arid region, hasspontaneous emergences of groundwater together with the generalNE sloping of the plain towards the Euphrates River (Marcolongoand Palmieri, 1983, Fig. 1c) giving rise to a present-day flourishingand intensive cultivation of apricot trees and riparian vegetationalong the channels. This indicates that the aquifer plays animportant local role. According to Fig. 1c, today the main rechargeof the aquifer system outside the hydrological basin comes from themountain chain located SSE of Arslantepe. A conspicuous recharge(producing high level of the groundwater fundamental for oak, seeValentini et al., 1992) should occur during winter/early spring andcould support oak, even if summer drought is long. Therefore, in thepast this naturally water fed area could have been occupied bydeciduous oak stands.

Minima in the juniper curve, likely recording less availability ofprecipitation water, precede the minima of the deciduous oakrecord. This may suggest also that a time lag exists betweenprecipitation and aquifer recharge. The two curves seem to beshifted, with the deciduous oak one moved towards more recenttime. It is not possible to be precise in assessing this delay betweenthe two curves because the records are necessarily not continuous(dependent on available archaeological charcoals) and the timingnot very precise, with the typical uncertainty of palaeorecords(Zanchetta et al., 2011). The succession of the events is pretty sureeven if single date errors could be estimated at some tens of years.Keeping in mind these limiting factors, the time lag between thetwo records is approximately 50e150 years. The minimum in thejuniper curve recorded at 3100 BC and reflecting local aridity wouldbe recorded in the deciduous oak curve ca. 50 years later (ca. 3050e3000 BC), when the aquifer could have been recharged. This patternrecurs three times (see the arrows in Fig. 4a), with minima in thejuniper record at ca. 3350, 3100 and 2300 BC. This would imply thatoaks display a significant delay in recording regional aridity.

Although several climate records for the mid-Holocene of theMediterranean basin compared and synchronized are now (Pérez-Obiol et al., 2011; Roberts et al., 2011a, 2011b; Sadori et al., 2011;Vannière et al., 2011), seasonal changes and dynamics are stillrarely explored (Stevens et al., 2001, 2006; Aguilera et al., 2012) andoften provide contrasting patterns of precipitation (e.g. Magnyet al., 2012). The available lake isotope records from the EastMediterranean (Roberts et al., 2008, 2011b) indicate possiblecontrasts in climate history during mid-Holocene. A similarpossible contrast is found in a core taken at the south-east marginof the Aegean Sea (Triantaphyllou et al., 2009). The time spaninvestigated at Arslantepe mostly overlaps the period of layer SMH(Sapropel mid-Holocene) deposition, generally interpreted asa humid period occurring between 3450 and 2350 BC (between5400 and 4300 BP), in which pollen curves show rather highvariability. After 2350 BC (4300 BP), a drier phase is found.

Similar trends are found between the oak curve (Fig. 4a) and thed18O one of Eski Acıgöl lake sediments (Fig. 4b, Roberts et al., 2001,2008). They both show the most significant drop at ca. 2200 BC andan increase in humidity at the top. Speleothems of Soreq cave inIsrael (Fig. 4c and d, Bar-Matthews and Ayalon, 2011) suggest thata phase with high climate instability occurred between 3300 and2900 BC, similarly to that recorded in the charcoals from Arslan-tepe. Arslantepe and Soreq records (both d18O and d13C) showsignificant minima of humidity around 3000 BC, while from ca.2850 to 2300 BC the isotopic curve of juniper shows meaningfulcorrespondences with the Soreq curve: both palaeorecords showhumidity decreases. A signal of drought is found in both records at

ca. 2300 BC. Bar-Matthews and Ayalon (2011) identified severalshort-lived decadal- to centennial-scale climatic events during themid-Holocene in Israel. At Soreq cave, in the time-span recorded atArslantepe, they found two dry events (both detectable also in thecharcoal record) occurring at 3300e3220 BC (5250e5170 BP) and2250e2100 BC (4200e4050 BP), which coincided respectively withthe cultural collapse of the Uruk society in Mesopotamia (latefourth millennium BC) and of the Akkadian Empire (late thirdmillennium BC).

The Arslantepe D13C record from charcoals and the Lake Vand18O curve from sediments (Fig. 4e, Wick et al., 2003) do not showclear similarities, but both records show aridity around 3100 and2300 BC and a slight increase in aridity before 2000 BC. The pollenrecords of Lake Van (Wick et al., 2003; Litt et al., 2009) showminorfluctuations of arboreal pollen percentages in the time windowconsidered in this study. The most important forest opening isfound at ca. 2000 BC. Two minima, respectively centred at ca. 3400and 2200 BC are found in the AP % of the pollen record ofMirabad inIran (van Zeist and Bottema,1977; Stevens et al., 2006), interruptinga significant wood expansion. It is, however, to be taken intoaccount that stable isotope records from lakes are sometimes inapparent conflict with pollen records, at least in central-easternMediterranean (e.g., Eastwood et al., 2007; Gasse et al., 2011;Zanchetta et al., 2012).

At 2900 BC, Arslantepe charcoals show the highest isotope valuefor deciduous oaks and a maximum in the juniper curve. Asuccessive well-knownperiod of reducedmoisture occurred duringmid-Holocene at ca. 2200 BC (around 4200 BP) all over the Medi-terranean basin and the Near East region (Bar-Matthews et al.,1997; Wick et al., 2003; Drysdale et al., 2006; Staubwasser andWeiss, 2006; Magny et al., 2009; Bar-Matthews and Ayalon, 2011;Sadori et al., 2011; Roberts et al., 2011a, 2011b). It probably matchedgreat and abrupt changes in the Old World societies (Hassan, 1997;Possehl, 1997; Weiss, 1997; Ristvet and Weiss, 2005). Zanchettaet al. (2011) interpreted this event in the Mediterranean (inparticular with summer drought) as a signal of marked seasonality.

Enzel et al. (2003) proposed a simple model for modern stormtracks in the eastern Mediterranean: during the driest winters,rainstorms are directed towards western Turkey, while during wetwinters rainstorms also impact the southern Levant. This modelcould explain the fact that major similarities are found respectivelybetween the juniper (water demanding) curve and d18O curve oflake Van, and between deciduous oaks (drought resistant taxa) andSoreq speleothem records. Wettest winters would be betterrecorded in the first, and driest in the latter ones.

6. Conclusions

Comparing past and present D13C values, the situation today issimilar to the one that occurred around 2300 BC. The combinationof the two records suggests that at present winter precipitation islower than that recorded during the period 3350e2000 BC andsummer aridity less or equal to that recorded ca. 2200 BC.

Changes in precipitation seasonality and the complex andpeculiar hydrogeological situation hindered the interpretation ofthe isotope records. Overall, 13C/12C contrasting ratios in juniper anddeciduous oaks suggest that seasonality in rainfall distribution andaquifer recharge play a complex role. The two agents often interfere,making it hard to distinguish the climate signals. In the particularenvironmental situation of Malatya, the two arboreal records aresensitive to two different climatic signals, one (provided by juniper)dependingon local precipitation and short in time, one (provided byoaks) probably more related with summer drought and the time ofaquifer recharge from themountain regions outside the catchment,and possibly therefore delayed in time for karst phenomena.

A. Masi et al. / Quaternary International 303 (2013) 64e72 71

These contrasting climatic records are probably evidence of thecomplexity of the Mediterranean climate, which may reflect con-trasting influences from both higher latitudes and lower latitudes.In the investigated period, eastern Anatolian climate was probablychanging, subject to the influence of mid-latitude cyclones gener-ated in the North Atlantic Ocean and in the Mediterranean Basin.The effects of the change on vegetation are probably so inter-fingered that only future studies on other arboreal taxa will shednew light on the matter. It is clear that establishing climate signalsfrom the isotope values of plant materials requires detailedknowledge of the ecosystem’s response behaviour. Under this light,the comparison with modern vegetation and meteorological dataindicated that present-day climate is drier than during the period3350e2000 BC and similar to that in the period of drought recordedat 4300e4200 BP.

Acknowledgements

We especially thank Marcella Frangipane, director of the exca-vation of Arslantepe, for the opportunity to study the plant samplesof this unique site. We thank Gianni Siracusano for the help incollecting the modern plants. We are grateful to Luigi Dallai for hisanalytical support and for the access to the mass spectrometerfacilities. A special acknowledgment goes to Francesca BalossiRestelli, for the great support in the archaeological aspects.

This study is part of Alessia Masi’s PhD dissertation “Palae-oenvironmental reconstruction of the archaeological site ofArslantepe (Eastern Anatolia)”e Dottorato in Scienze Applicate allaProtezione dell’Ambiente e dei Beni Culturali (XXIV ciclo), Uni-versità di Roma “La Sapienza”. The workwas partly financed by twoItalian projects, PRIN 2006, “Economy and Power: an analysis oftypes and degrees of central control over economy, from theearliest hierarchical communities to the palatial societies in Ana-tolia and the Aegean” and PRIN 2008, PICAR (2008FJCEF4) “Culturallandscape and human impact in circum-Mediterranean countries”.

References

Aguilera, M., Araus, J.L., Voltas, J., Rodríguez-Ariza, M.O., Molina, F., Rovira, N.,Buxó, R., Ferrio, J.P., 2008. Stable carbon and nitrogen isotopes and quality traitsof fossil cereal grains provide clues on sustainability at the beginnings ofMediterranean agriculture. Rapid Communications in Mass Spectrometry 22,1653e1663.

Aguilera, M., Ferrio, J.P., Araus, J.L., Tarrùs, L., Voltas, J., 2011. Climate at the onset ofwestern Mediterranean agriculture expansion: evidence from stable isotopes ofsub-fossil oak tree rings in Spain. Palaeogeography, Palaeoclimatology, Palae-oecology 299, 541e551.

Aguilera, M., Ferrio, J.P., Pérez, G., Araus, J.L., Voltas, J., 2012. Holocene changes inprecipitation seasonality in the western Mediterranean Basin: a multi-speciesapproach using d13C of archaeobotanical remains. Journal of QuaternaryScience 27, 192e202.

Alessio, M., Allegri, L., Azzi, C., Bella, F., Calderoni, G., Cortesi, C., Improta, S.,Petrone, V., 1983. 14C dating of Arslantepe. Origini 12, 575e580.

Alvaro, C., Sadori, L., Masi, A., Susanna, F., 2010. Timber use at the end of the 4thmillennium BC at Arslantepe. In: Frangipane, M. (Ed.), The ArchaeologicalReconstruction of the Economic System in 4th Millennium Arslantepe. Studi diPreistoria Orientale (SPO), vol. 3. Sapienza Università di Roma, pp. 81e93.

Araus, J.L., Buxó, R., Febrero, A., Rodríguez-Ariza, M.O., Molina, F., Camalich, M.D.,Martín, D., Voltas, J., 1997a. Identification of ancient irrigation practices basedon the carbon isotope discrimination of plant seeds: a case study from thesoutheast Iberian peninsula. Journal of Archaeological Science 24, 729e740.

Araus, J.L., Febrero, A., Buxó, R., Camalich, M.D., Martín, D., Molina, F., Rodríguez-Ariza, M.O., Romagosa, I., 1997b. Changes in carbon isotope discrimination ingrain cereals from different regions of the western Mediterranean Basin duringthe past seven millennia. Palaeoenvironmental evidence of a differential changein aridity during the late Holocene. Global Change Biology 3, 107e118.

Araus, J.L., Villegas, D., Aparicio, N., García del Moral, L.F., El Hani, S., Rharrabti, Y.,Ferrio, J.P., Royo, C., 2003. Environmental factors determining carbon isotopediscrimination and yield in Durum wheat under Mediterranean conditions.Crop Science 43, 170e180.

Asouti, E., Austin, P., 2005. Reconstructing woodland vegetation and its exploitationby past societies, based on the analysis and interpretation of archaeologicalwood charcoal macro-remains. Environmental Archaeology 10, 1e18.

Asouti, E., Hather, J., 2001. Charcoal analysis and the reconstruction of ancientwoodland vegetation in the Konya Basin, south-central Anatolia, Turkey: resultsfrom the Neolithic site of Çatalhöyük East. Vegetation History and Archae-obotany 10, 23e32.

Atalay, I., 2004. Mountain ecosystems of Turkey. In: Proc. of the 7th InternationalSymposium on High Mountain Remote Sensing Cartography, Bishkek,Kyrgyzstan July, 2002. Institute for Cartography Dresden University of Tech-nology, Germany, pp. 29e38.

Baneschi, I., Masi, A., Sadori, L., Zanchetta, G., 2012. The use of stable carbonisotopes in palaeoenvironmental studies in archaeology: the example ofArslantepe (Malatya, Eastern Anatolia) from 5300 to 3950 years BP. Rend OnlineSocieta Geologica Italia 18, 8e11.

Bar-Matthews, M., Ayalon, A., Kaufman, A., 1997. Late Quaternary paleoclimate inthe Eastern Mediterranean region from stable isotope analysis of speleothemsat Soreq Cave, Israel. Quaternary Research 47, 155e168.

Bar-Matthews, M., Ayalon, 2011. Mid-Holocene climate variations revealed by high-resolution speleothem records from Soreq Cave, Israel and their correlationwith cultural changes. The Holocene 21, 163e171.

Bulut, Z., Yilmaz, H., 2010. The current situation of threatened endemic flora inTurkey: Kemaliye (Erzincan) case. Pakistan Journal of Botany 42, 711e719.

Calderoni, G., Caneva, I., Cazzella, A., Frangipane, M., Petrone, V., 1994. Departmentof Earth Sciences and the University of Rome radiocarbon dates, III. Radiocarbon36, 143e152.

Chen, S., Bai, Y., Lin, G., Han, X., 2005. Variations in life-form composition and foliarcarbon isotope discrimination among eight plant communities under differentsoil moisture conditions in the Xilin River Basin, Inner Mongolia, China.Ecological Research 20, 167e176.

Davis, P.H., 1965. Flora of Turkey and the East Aegean Islands, vols. 1e9. EdinburghUniversity Press.

Davis, P.H., 1971. Distribution patterns in Anatolia with particular reference toendemism. In: Davis, P.H., Harper, P.C., Hedge, I.C. (Eds.), Plant Life of South-west Asia. Botanical Society of Edinburgh, Edinburgh, pp. 15e28.

De Niro, M.J., Hastorf, C.A., 1985. Alteration of 15N/14N and 13C/12C ratios of plantmatter during the initial stages of diagenesis: Studies utilizing archaeologicalspecimens from Peru. Geochimica et Cosmochimica Acta 49, 97e115.

Diamond, J., 2005. Collapse: How Societies Choose to Fail or Succeed. Viking Books,New York.

Drysdale, R., Zanchetta, G., Hellstrom, J., Maas, R., Fallick, A.E., Pickett, M.,Cartwright, I., Piccini, L., 2006. Late Holocene drought responsible for thecollapse of Old Wold civilizations is recorded in an Italian cave flowstone.Geology 34, 101e104.

Eastwood, W.J., Leng, M.J., Roberts, N., Davis, B., 2007. Holocene climate change in theeastern Mediterranean region: a comparison of stable isotope and pollen datafrom Lake Gölhisar, southwest Turkey. Journal of Quaternary Science 22, 327e341.

Edwards, T.W.D., Graf, W., Trimborn, P., Stichler, W., Lipp, J., Payer, H.D., 2000. 13Cresponse surface resolves humidity and temperature signals in trees. Geo-chimica et Cosmochimica Acta 64, 161e167.

Ehleringer, J.R., 1989. Carbon isotope ratios and physiological processes in arid landplants. In: Rundel, P.W., Ehleringer, J.R., Nagy, K.A. (Eds.), Stable Isotopes inEcological Research. Springer-Verlag, New York.

Ehleringer, J.R., 1993. Variation in leaf carbon isotope discrimination in Enceliafarinosa: implications for growth, competition, and drought survival. Oecologia95, 340e346.

Ehleringer, J.R., Dawson, T.E., 1992. Water uptake by plants: perspectives from stableisotope composition. Plant Cell Environment 15, 1073e1082.

Ehleringer, J.R., Phillips, S.L., Comstock, J.P., 1992. Seasonal variation in the carbonisotopic composition of desert plants. Functional Ecology 6, 396e404.

Enzel, Y., Bookman, R., Sharon, D., Gvirtzman, H., Dayan, U., Baruch, Z., Stein, M., 2003.Late Holocene climates of the Near East deduced from Dead Sea level variationsand modern regional winter rainfall. Quaternary Research 60, 263e273.

Eyer, M., Leuenberger, M., Nyfeler, P., Stocker, T.F., 2004. Comparison of two d13CO2records measured on air from the EPICA Dome C and Kohnen Station ice cores.Geophysical Research Abstracts 6, 1990.

Farquhar, G.D., Ehleringer, J.R., Hubik, K.T., 1989. Carbon isotope discrimination andphotosynthesis. Annual Review of Plant Physiology 40, 503e537.

Farquhar, G.D., von Caemmerer, S.V., Berry, J.A., 1980. A biochemical-model ofphotosynthetic CO2 assimilation in leaves of C3 plants. Planta 149, 78e90.

Ferrio, J.P., Araus, J.L., Buxó, R., Voltas, J., Bort, J., 2005. Water management practicesand climate in ancient agriculture: inferences from the stable isotope compo-sition of archaeobotanical remains. Vegetation History and Archaeobotany 14,510e517.

Fiorentino, G., Caracuta, V., Calcagnile, L., D’Elia, M., Matthiae, P., Mavelli, F.,Quarta, G., 2008. Third millennium BC climate change in Syria highlighted bycarbon stable isotope analysis of 14C-AMS dated plant remains from Ebla.Palaeogeography, Palaeoclimatology, Palaeoecology 266, 51e58.

Frangipane, M., 2004. Alle origini del potere. Arslantepe, la collina dei leoni. ElectaMondadori, Milano.

Frangipane, M., Palmieri, A., 1983. Perspectives on protourbanization in easternAnatolia: Arslantepe (Malatya). An interim report on 1975e1983 campaigns.Origini 12, 287e668.

Gasse, F., Vidal, L., Develle, A.-L., Van Campo, E., 2011. Hydrological variability innorthern Levant over the past 250 ka. Climate of the Past Discussions 7,1511e1566.

Greguss, P., 1955. Identification of Living Gymnosperms on the Basis of Xylotomy.Akadémiai Kiadó, Budapest.

A. Masi et al. / Quaternary International 303 (2013) 64e7272

Hall, G., Woodborne, S., Scholes, M., 2008. Stable carbon isotope ratios fromarchaeological charcoal as palaeoenvironmental indicators. Chemical Geology247, 384e400.

Hassan, F., 1997. Nile floods and political disorder in early Egypt. In: Dalfes, H.N.,Kukla, G., Weiss, H. (Eds.), Third Millennium B.C. Climate Change and Old WorldCollapse, vol. 49. Springer, Berlin, pp. 1e23.

Hemming, D.L., Switsur, V.R., Waterhouse, J.S., Heaton, T.H.E., Carter, A.H.C., 1998.Climate and the stable carbon isotope composition of tree ring cellulose: anintercomparison of three tree species. Tellus 50B, 25e32.

IPCC, 2012. Managing the risks of extreme events and disasters to advance climatechange adaptation. In: Field, C.B., Barros, V., Stocker, T.F., Qin, D., Dokken, D.J.,Ebi, K.L., Mastrandrea, M.D., Mach, K.J., Plattner, G.-K., Allen, S.K., Tignor, M.,Midgley, P.M. (Eds.), A Special Report of Working Groups I and II of the Inter-governmental Panel on Climate Change. Cambridge University Press, Cam-bridge, UK, and New York, USA, 582 pp.

Indermühle, A., Stocker, T.F., Joos, F., Fischer, H., Smith, H.J., Wahlen, M., Deck, B.,Mastroianni, D., Tschumi, J., Blunier, T., Meyer, R., Stauffer, B., 1999. Holocenecarbon-cycle dynamics based on CO2 trapped in ice at Taylor Dome, Antarctica.Nature 398, 121e126.

Kuniholm, P.I., 1996. The prehistoric Aegean: dendrochronological progress as of1995. Acta Archaeologica 67, 327e335.

Leavitt, S.W., 2002. Prospects for reconstruction of seasonal environment from tree-ringd13C: baselinefindings from theGreat Lakes area,USA.Chemical Geology 191, 47e58.

Leavitt, S.W., Newberry, T., 1992. Systematics of stable-carbon isotopic differencesbetween gymnosperm and angiosperm trees. Plant Physiology 11, 257e262.

Leuenberger, M., Siegenthaler, U., Langway, C.C., 1992. Carbon isotope compositionof atmospheric CO2 during the last ice age from an Antartic ice core. Nature 357,488e490.

Litt, T., Krastel, S., Sturm, M., Kipfer, R., Orcen, S., Heumann, G., Franz, S.O.,Ulgen, U.B., Niessen, F., 2009. `PALEOVAN’, International Continental ScientificDrilling Program (ICDP): site survey results and perspectives. QuaternaryScience Reviews 28, 1555e1567.

Loader, N.J., Robertson, I., McCarroll, D., 2003. Comparison of stable carbon isotoperatios in the whole wood cellulose and lignin of oak tree-rings. Palae-ogeography, Palaeoclimatology, Palaeoecology 196, 395e407.

Magny, M., Peyron, O., Sadori, L., Ortu, E., Zanchetta, G., Vannière, B., Tinner, W., 2012.Contrasting patterns of precipitation seasonality during the Holocene in the south-and north-central Mediterranean. Journal of Quaternary Science 27, 290e296.

Magny, M., Vannière, B., Zanchetta, G., Fouache, E., Touchais, G., Petrika, L.,Coussot, C., Walter-Simonnet, A.V., Arnaud, F., 2009. Possible complexity of theclimatic event around 4300e3800 cal. BP in the central and western Mediter-ranean. The Holocene 19, 1e11.

Marcolongo, B., Palmieri, A.M., 1983. Environment, water supply and culturaldevelopment at Arslantepe (Malatya, Turkey). Origini 12, 619e628.

Masi, A., Sadori, L., Baneschi, I., Siani, A.M., Zanchetta, G., 2012. Stable isotopeanalysis of archaeological oak charcoal from eastern Anatolia as a marker ofmid-Holocene climate change. Plant Biology. in press.

McCarroll, D., Loader, N.J., 2004. Stable isotopes in tree rings. Quaternary ScienceReviews 23, 771e801.

Mercuri, A.M., Sadori, L., Blasi, C., 2010. Archaeobotany for cultural landscape andhuman impact reconstructions. Plant Biosystem 144, 860e864.

Mercuri, A.M., Sadori, L., Uzquiano Ollero, P., 2011. Mediterranean and north-Africancultural adaptations to mid-Holocene environmental and climatic changes. TheHolocene 21, 189e206.

Miller, J.M., Williams, R.J., Farquhar, G.D., 2001. Carbon isotope discrimination bya sequence of Eucalyptus species along a subcontinental rainfall gradient inAustralia. Functional Ecology 15, 222e232.

Pérez-Obiol, R., Jalut, G., Julià, R., Pèlachs, A., Iriarte, M.J., Otto, T., Hernández-Beloqui, B., 2011. Mid-Holocene vegetation and climatic history of the IberianPeninsula. The Holocene 21, 75e93.

Possehl, G., 1997. Climate and the eclipse of the ancient cities of the Indus. In:Dalfes, H.N., Kukla, G., Weiss, H. (Eds.), Third Millennium B.C. Climate Changeand Old World Collapse, vol. 49. Springer, Berlin, pp. 193e244.

Riehl, S., 2008. Climate and agriculture in the ancient Near East: a synthesis of thearchaeobotanical and stable carbon isotope evidence. Vegetation History andArchaeobotany 17, 43e51.

Riehl, S., Bryson, R.A., Pustovoytov, K., 2008. Changing growing conditions for cropsduring the Near Eastern Bronze Age (3000-1200 B.C.): the stable carbon isotopeevidence. Journal of Archaeological Science 35, 1011e1022.

Ristvet, L., Weiss, H., 2005. The Habur Region in the late third and early secondmillennium BC. In: Orthmann, W. (Ed.), The History and Archaeology of Syria.Saarbrücken Verlag, Saarbrücken.

Roberts,N., Reed, J.M., Leng,M.J., Kuzucuo�glu,C., Fontugne,M.,Bertaux, J.,Woldring,H.,Bottema, S., Black, S., Hunt, E., Karabiyiko�glu, M., 2001. The tempo of Holoceneclimate change in the eastern Mediterranean region: new high-resolution crater-lake sediments data from central Turkey. The Holocene 11, 721e736.

Roberts, N., Jones, M.D., Benkaddour, A., Eastwood, W.J., Filippi, M.L., Frogley, M.R.,Lamb, H.F., Leng, M.J., Reed, J.M., Stein, M., Stevens, L., Valero-Garcé, B.,

Zanchetta, G., 2008. Stable isotope records of Late Quaternary climate andhydrology from Mediterranean lakes: the ISOMED synthesis. QuaternaryScience Reviews 27, 2426e2441.

Roberts, N., Brayshaw, D., Kuzucuo�glu, C., Perez, R., Sadori, L., 2011a. The mid-Holocene climatic transition in the Mediterranean: causes and consequences.The Holocene 21, 3e13.

Roberts, N., Eastwood, W.J., Kuzucuoglu, C., Fiorentino, G., Caracuta, V., 2011b.Climate, vegetation and cultural change in the eastern Mediterranean duringthe mid-Holocene environmental transition. The Holocene 21, 147e162.

Sadori, L., Giardini, M., Giraudi, C., Mazzini, I., 2010a. The plant landscape of theImperial harbour of Rome. Journal of Archaeological Science 37, 3294e3305.

Sadori, L., Mercuri, A.M., Mariotti Lippi, M., 2010b. Reconstructing past culturallandscape and human impact using pollen and plant macroremains. PlantBiosystem 144, 940e951.

Sadori, L., Jahns, S., Peyron, O., 2011. Mid-Holocene vegetation history of the centralMediterranean. The Holocene 21, 117e129.

Sadori, L., Susanna, F., Balossi Restelli, F., 2008. Collapsed beams and woodenremains from a 3200 BC temple and palace at Arslantepe (Malatya, Turkey). In:Fiorentino, G., Magri, D. (Eds.), Charcoals from the Past: Cultural and Palae-oenvironmental Implications. Proceedings of the Third International Meeting ofAnthracology, Cavallino e Lecce (Italy), June 28theJuly 1st 2004. BAR Interna-tional Series 1807, pp. 103e116.

Sadori, L., Susanna, F., Persiani, C., 2006. Archaeobotanical data and crop storageevidence from an early Bronze Age 2 burnt house at Arslantepe, Malatya,Turkey. Vegetation History and Archaeobotany 15, 205e215.

Schweingruber, F.H., 1990. Anatomie europäischer Hölzer. W.S.L. F.N.P. Haupt, Bernund Stuttgart, Birmensdorf.

Sensoy, S., Demircan, M., Ulupınar, U., Balta, _I., 2008. Türkiye _Iklimi. DM_I. www.dmi.gov.tr/iklim/iklim.aspx.

Staubwasser, M., Weiss, H., 2006. Holocene climate and cultural evolution in lateprehistoric-early historic West Asia. Quaternary Research 66, 372e387.

Steinbeiss, S., Schmidt, C.M., Heide, K., Gleixner, G., 2006. d13C values of pyrolysisproducts from cellulose and lignin represent the isotope content of theirprecursors. Journal of Analytical and Applied Pyrolysis 75, 19e26.

Stevens, L.R., Wright Jr., H.E., Ito, E., 2001. Proposed changes in seasonality ofclimate during the Lateglacial and Holocene at Lake Zeribar, Iran. The Holo-cene 11, 747e755.

Stevens, L.R., Ito, E., Schwalb, A., Wright Jr., H.E., 2006. Timing of atmosphericprecipitation in the Zagros Mountains inferred from a multi-proxy record fromLake Mirabad, Iran. Quaternary Research 66, 494e500.

Triantaphyllou, M.V., Ziveri, P., Gogou, A., Marino, G., Lykousis, V., Bouloubassi, I.,Emeis, K.-C., Kouli, K., Dimiza, M., Rosell-Melé, A., Papanikolaou, M.,Katsouras, G., Nunez, N., 2009. Late Glacial-Holocene climate variability at thesouth-eastern margin of the Aegean Sea. Marine Geology 266, 282e297.

Valentini, R., Mugnozza, G.E.S., Ehleringer, J.R., Scarascia-Mugnozza, G.E., 1992.Hydrogen and carbon isotope ratios of selected species of Mediterraneanmacchia ecosystem. Functional Ecology 6, 627e631.

Vannière, B., Power, M.J., Roberts, N., Tinner, W., Carrión, J., Magny, M., Bartlein, P.,Colombaroli, D., Daniau, A.L., Finsinger, W., Gil-Romera, G., Kaltenrieder, P.,Pini, R., Sadori, L., Turner, R., Valsecchi, V., Vescovi, E., 2011. Circum-Mediter-ranean fire activity and climate changes during the mid-Holocene environ-mental transition (8500e2500 cal. BP). The Holocene 21, 53e73.

van Zeist, W., Bottema, S., 1977. Palynological investigations in western Iran.Palaeohistoria 24, 19e85.

Warren, C.R., McGrath, J.F., Adams, M.A., 2001. Water availability and carbon isotopediscrimination in conifers. Oecologia 127, 476e486.

Weiss, H., 1997. Late third millennium abrupt climate change and social collapse inWest Asia and Egypt. In: Dalfes, H.N., Kukla, G., Weiss, H. (Eds.), Third Millen-nium BC Climate Change and Old World.Collapse. NATO ASI Series. Springer,Berlin Heidelberg, pp. 711e724.

Wick, L., Lemcke, G., Sturm, M., 2003. Evidence of Late glacial and Holocene climaticchange and human impact in eastern Anatolia: high-resolution pollen, charcoal,isotopic and geochemical records from the laminated sediments of Lake Van,Turkey. The Holocene 13, 665e675.

Yildiz, B., Aktoklu, E., 1996a. C7 Karesinden (Malatya-Adiyaman) Yeni FloristikKayitlar. Turkish Journal of Botany 20, 207e211.

Yildiz, B., Aktoklu, E., 1996b. Malatya Florasina Katkilar I Sürgü-Çelikhan Yöresindebir Ön. Çalisma. Turkish Journal of Botany 20, 267e278.

Yildiz, B., Bahçecio�glu, Z., Arabaci, T., 2004. Floristic characteristics of Beyda�gi(Malatya). Turkish Journal of Botany 28, 391e419.

Zanchetta, G., Sulpizio, R., Roberts, N., Cioni, R., Eastwood, W.J., Siani, G., Caron, B.,Paterne, M., Santacroce, R., 2011. Tephrostratigraphy, chronology and climaticevents of the Mediterranean basin during the Holocene: an overview. TheHolocene 21, 33e52.

Zanchetta, G., Van Welden, A., Baneschi, I., Drysdale, R., Sadori, L., Roberts, N.,Giardini, M., Beck, C., Pascucci, V., Sulpizio, R., 2012. Multiproxy record forthe last 4500 years from Lake Shkodra (Albania/Montenegro). Journal ofQuaternary Science 27, 780e789.