Palaeogeography, Palaeoclimatology, Palaeoecologycampisabalos.es/documentos/yacimiento_de_valdojos_ingles.pdfIt comprises a succession of mountain ranges originating in central Portugal

Palaeogeography, Palaeoclimatology, Palaeoecology 441 (2016) 811–822

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Palaeogeography, Palaeoclimatology, Palaeoecology

j ourna l homepage: www.e lsev ie r .com/ locate /pa laeo

Early Holocene vegetation in the Ayllón Massif (Central System Range,Spain) based on macroremains. A paleoecological approach

Mar Génova ⁎, Fernando Gómez-Manzaneque, Felipe Martínez-García, José Mª. Postigo-MijarraDepartamento de Sistemas y Recursos Naturales, Escuela de Ingeniería de Montes, Forestal y del Medio Natural, Universidad Politécnica de Madrid, 28040 Madrid, Spain

⁎ Corresponding author at: Departamento de Sistemas yPolitécnica de Madrid, 28040 Madrid, Spain. Tel.:+34 91 33

E-mail addresses:[email protected] (M. Génova), f(F. Gómez-Manzaneque), [email protected] (F. [email protected] (J.M.ª Postigo-Mijarra).

http://dx.doi.org/10.1016/j.palaeo.2015.10.0270031-0182/© 2015 Elsevier B.V. All rights reserved.

a b s t r a c t

Article history:Received 25 May 2015Received in revised form 13 October 2015Accepted 16 October 2015Available online 24 October 2015

Keywords:PalaeobiogeographyMacroremainsDendrochronologySpainPinus cf. sylvestrisBos primigenius

Wepresent a palaeoecological study ofwell-preserved vegetalmacroremains in Spain,which age range (10,025–5371 cal yr BP) confers it an outstanding interest, because for the first half of the Holocene, palaeobotanical dataare extremely scarce in the Iberian Central System Range.We found, for the first time in the easternmost zone ofthe Central System Range, macroremains belonging to the genus Pinus; these have specifically been identified asPinus cf. sylvestris and Pinus gr. sylvestris. These findings provide valuable information on the role of the genusPinus, regarding the natural character of these pine forests in this relatively unknown region.In the largerwood sampleswemeasured tree rings and cross-dated growth series,which represent a 75% increase inthe number of floating fossil chronologies and increase the time span by almost 1750 years, in the centre of theIberian Peninsula. Remarkably, this is the first time in Spain and in southern Europe that some of the floating chro-nologies have been successfully crossdated, creating four composite chronologies. Furthermore, we discuss somepalaeoclimatic inferences comparingwith different sites in southern Europe and provide newdata for best knowingthepalaeoecological characteristics of thefirst half of theHolocene in Spain. Likewise,we found twobones belongingto aurochs (Bos primigenius), one of these also dating from the first half of the Holocene, with Valdojos constitutingthe only site with this taxon for this period in the Central System Range and surrounding areas.

© 2015 Elsevier B.V. All rights reserved.

1. Introduction

In the last fewdecades, the relevance of the genus Pinus and the role itplayed in the Iberian ecosystems throughout the Holocene has arousedintense debate and given rise to abundant research (e.g. Carrión et al.,2000a, 2010; Franco-Múgica et al., 2000, 2001a; Rubiales et al., 2010;García-Antón et al., 2011). In areas presenting notable anthropic activity,such as the Central System Range, palaeobotanical research is necessaryto understand the nature of changes in the anthropogenic landscapes.Thus, although abundant palynological studies have referred to the Cen-tral System Range, fundamentally in the Estrela, Béjar, Francia, Gredosand Guadarrama mountains (López-Sáez et al., 2013) the eastern sectorof this large mountain range, known as the Ayllón Massif, remains rela-tively unexplored in the palaeobotanical sense.

To date, the scarce available information on thesemountains consistsof a few palynological studies presenting no accurate chronology(Hernández-Vera and Ruiz-Zapata, 1984; Jiménez-Ballesta et al., 1985;Ruiz del Castillo, 1993) and some others dated by radiocarbon(Gil-García et al., 1994; Franco-Múgica et al., 2001a, 2001b; Currás

Recursos Naturales, [email protected]ínez-García),

et al., 2012). Interestingly, all this research provides only informationon the recent past (the last 4000 yr BP), and no study addressing theAyllón Massif gives any information on the palaeovegetation existingin the area for the first half of the Holocene. The scarce palaeobotanicalinformation has contributed to generate different interpretations onthe natural vegetation, especially with regard to the role played bypine forests in this region (Martínez-García and Costa Tenorio, 2001;Martínez-García, 2002). In fact, besides thementioned palynological in-formation, different authors have discarded the presence of natural for-mations of these species in the area, being interpreted the current pineforest in the region only as a result of recent afforestations (De laFuente, 1985; Monje-Arenas, 1987; Peinado-Lorca and Martínez Parras,1987; Rivas-Martínez, 1987; Rivas-Martínez et al., 2011). On the otherhand, any particular species belonging to the genus Pinus has been de-termined by means the palynological studies. Macroremains studies inthe eastern area of this Rangemay significantly help to knowwhich spe-cies occurred in these pre-anthropic forests. The only studies conductedto date addressing vegetal macroremains in the Central Range refer tothe western sector — the Gredos mountains, Fig. 1 — (Rubiales et al.,2007; Génova et al., 2009; Rubiales and Génova, 2015). Our study ofthe Valdojos site, in the eastern sector, therefore greatly broadens thegeographical range of research on vegetal macroremains in the centreof the Iberian Peninsula. Additionally, the only dendrochronologicalstudies on macroremains in Spain also involved the above mentionedresearch for the Gredos mountains. Although these constitute a very

Estrela

Gata Gredos

Guadarrama

Ayllón

Francia

Béjar

Somosierra

Valdojos site

Fig. 1. Situation of the Central and Iberian System Ranges inland on the Iberian Peninsula. The enlarged box on the right shows the different mountains making up the Central SystemRange, and the location of the site studied is indicated in red.

812 M. Génova et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 441 (2016) 811–822

important milestone for the creation of multimillenial chronologies inSpain, they involve mainly short floating sequences (Rubiales andGénova, 2015).

Consequently, we have pursued the following aims in this work:

– To identify the taxa of the remains found and to evaluate theirbiogeographical role (spatial and temporal) in the eastern CentralSystem Range.

– To study the palaeoecological information provided by the tree ringgrowth sequences from the dendrochronological perspective.

– To analyse the data we have obtained, comparing them with otherpre-existing palaeobotanical information in order to contribute todesigning a vegetation evolution model for the region.

2. Regional setting

The Central SystemRange of the Iberian Peninsula constitutes a largemountain range over 500 km long (one of the longest in the Mediterra-nean Basin), running from West to East. It comprises a succession ofmountain ranges originating in central Portugal (Estrela mountains)and continuing in Spain: the Gata, Francia, Béjar, Gredos (presentingthe highest point — Almanzor peak, 2592 m asl–), Guadarrama,Somosierra and Ayllón ranges (Fig. 1). This mountain chain is so long,with such a broad altitudinal gradient, that it ranges from 300 to over2500 m asl; it is highly heterogeneous from the climatic point of view(Ruiz-Labourdette et al., 2010). To simplify, it could be said that themore Mediterranean environments are located on the southern slopeof the western part of the mountains, whereas the more Eurosiberianones correspond to the eastern end (Ayllón Massif). On the contrary,the more continental environments correspond to the central part(Guadarrama mountains).

From a geological point of view, in the Central SystemRange there is apredominance of granites and metamorphic materials, with much morelocalised cretaceous limestone enclaves (Muñoz and Sanz-Herráiz,1995). The orography, together with the climatic and geographic varia-tion, has provided the Central System Rangewith a high floristic diversity(Castro et al., 1996) and vegetation (Martínez-García and Costa Tenorio,2001). The basal forests basically comprise evergreen sclerophyllous for-mations of Holm oak (Quercus ilex subsp. ballota (Desf.) Samp.), generallybelow 1000–1200 m asl. These are substituted at higher altitudes by oak

forests of Quercus pyrenaica Willd., which comprise a belt of deciduoustrees between 1200 and 1500 m asl. Around this elevation, the oaksgive way to forests of Scots pine (P. sylvestris L.), which form forests upto approximately 2000 m asl. These pine formations are currently wellrepresented in themore continental sections of the Range (Guadarrama),becoming scarcer towards the east (Ayllón) and west (Gredos). Above2000 m asl the woody vegetation is represented by a bushy stratum ofLeguminosae (Cytisus,Genista, Echinospartum) or Ericaceae (Erica,Calluna,Arctostaphylos), which at higher altitudes gives way to alpine grassland(Luceño and Vargas, 1991; Costa et al., 1997). The E/W and N/S gradientsgive rise to local variations in the distribution of the plant communities,such as the presence of relict forests. This occurs, for instance, in theAyllón Massif, with the beech forests of Fagus sylvatica L.

The Ayllón Massif makes contact with the Iberian System Range, amountain range running through the east of the peninsula in the NW–SE direction. From the climatic perspective, the Ayllón Massifrepresents the least Mediterranean zone of the Central System Range,it provides refuge for numerous boreal and boreo alpine species(Luceño and Vargas, 1991; Martínez-García, 2001; Ruiz-Labourdetteet al., 2010) and also explain the presence of P. sylvestris forests andthe relict forests of beech (F. sylvatica) (Costa et al., 1997).

The Valdojos site (41° 14′ N, 3° 11′ W, 1320 m asl) is located in theAyllón Massif, within the municipality of Campisábalos (GuadalajaraProvince) (Fig. 1) and it comprises a marshy system covering an areaof approximately 5.5 ha. This site is located at the bottom of a valleyfilled with alluvial materials from the Holocene. It is located within ageological context of stratified limestone and dolomites of cretaceousorigin. In the surrounding area, these carbonated materials form smallgorges by means of dissolution processes. Among the deposits of thefluvial surface formations making up the valley bottom are limestoneboulders and dolomites. The matrix is clayey–sandy of a brown orreddish-brown colour. This layer of Holocene alluvial materials isquite undeveloped, and does not exceed 4\\5 m (Hernáiz et al., 2005).

The current vegetation in the immediate vicinity comprises pineforests of Pinus sylvestris, with dispersed stands of Juniperus communisL. subsp. hemisphaerica (C. Presl) Nyman, accompanied by typicallycalcicole species such as Teucrium capitatum L., Thymus leptophyllusLange subsp. izcoi (Rivas Mart., A Molina & G. Navarro) R. Morales,Satureja intricata Lange, Potentilla cinerea Chaix ex Vill., Sideritis hirsutaL., Teucrium chamaedrys L., Santolina chamaecyparissus L. or Aphyllanthesmonspeliensis L.

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3. Material and methods

3.1. Sampling

The mechanical work involved in the Valdojos afforestation, conduct-ed in the 1980s (Fernández Muñoz, 2002), uncovered numerous treeremains that have remained on the surface up to the present. We per-formed three samplings at the site where these trunks appeared. In thefirst two of these, in September 2011 and December 2012, we only col-lected samples that had risen to the surface. In the third one we used abackhoe to make 7 test holes at different points. The first test hole (0),in the centre of the valley, provided no samples. The remaining ones,test holes 1–6, were made in the lateral zones, where remains had risento the surface (Fig. 2). The test holes, approximately 3 m wide, reacheda depth ranging from 3.1 m in hole no. 1 to 4.2 m in hole no. 4; in mostcases, at these depths the transition between the more organic sedimentand the underlying mother rock occurred.

We collected all the wood we found from each test hole: a total of 26samples (Fig. 2). If one also counts the remains found on the surface, thereis a total of 46 samples (Table 1). Most of the large-sized samples werefound on the deposit surface or buried at shallow depths (not over1.5 m), and at greater depths only small remains were uncovered. More-over, in two of the test holes, no. 2 and no. 3, we found two bones in agood state of conservation.

3.2. Vegetal macroremains

Taking into account the size of the samples and their ring type,shape and width, they mainly correspond to small and large piecesof trunk. However, branches of different sizes and likely small piecesof roots also are present, all of which were analysed. Although thesepieces of wood present some evidence of biodegradation, carboniza-tion and carbonification processes, they were all studied without anyspecial treatments. These pieces of wood were found in differentpositions/orientations in the sediment. No upright trunks were observed.

Fig. 2.General view of the site and of the test holes. The image also shows one of the biggest rem1:400. Author: Laura Toro Bermejo.

Taphonomic distortion can also be observed in some samples, but ingeneral terms, this does not significantly prevent observation of the ana-tomical features. As a result, the wood can be classified as duriparticallypreserved (Schopf, 1975) or preserved in a basically unaltered state(Spicer, 1991). The displacements described for continental environ-ments of this type of macroremains (MacGinitie, 1969; Rich, 1989;Spicer, 1991) point to a native character of these macrofossils for thebasin (Fernández López, 1990). The presence of disarticulation processesshould not be ruled out, especially on the surface of the site, where differ-ent afforestation works have been conducted in the recent past.

3.2.1. Radiocarbon dating and calibrationWedated a total of 22wood samples, both from the surface and from

the 6 test holes made. The ones obtained from the test holes came fromvery different depths, ranging from the maximum of 4.2 m to samplescollected on the surface. The radiocarbon dateswere obtained from sam-ples taken from the outer rings of the logs with AMS (Queen's University,Belfast) and were calibrated using the Radiocarbon Calibration Program(Reimer et al., 2009). Calibrated ages are expressed as the median of thehigher probability of 2 σ cal yr BP, as suggested by Telford et al. (2004)(Table 1).

3.2.2. Wood anatomical analysisWe analysed all the wood pieces, both those found on the surface

and the ones removed from the test holes (a total of 46 samples),using traditional micrographic techniques (Schweingrüber, 1990;García et al., 2002). Fragments measuring approximately 1 × 1 × 2 cmwere processed with amicrotome to provide thin section slides approx-imately 15–25 μ thick. These slides were stained with safranin and thenwashed with distilled water and alcohol. Some samples were sub-merged in xylol and fixed with Euquit. The samples were observed bymeans of transmission light microscopy with an Olympus B × 50 seriesoptical microscope equipped with UIS lenses (magnification × 50,×100, ×200 and ×500). We identified the samples by referring to theclassic wood anatomy studies of Greguss (1955), Jacquiot (1955),

ains collected. The scale of the test holes, trunks and backhoe in relation to the landscape is

Table 1Number of samples showing its location (test hole or superficial –S–) and depth, conventional and calibrated age and identification.*: Calibrated age expressed as the median of the higher probability of 2 σ cal years BP.

Macroremain type ID Test hole/Depth (m) Lab reference Conventional 14C Age (yr BP) Cal Age* Identification

1 Wood fragments Val10 S – – – P. gr. sylvestris2 Wood fragments Val12 S UBA-19753 138 ± 42 225 P. gr. sylvestris3 Wood fragments Val13 S – – – P. gr. sylvestris4 Wood fragments Val14 S UBA-19752 105 ± 24 83 P. gr. sylvestris5 Trunk and wood fragments Val08 S UBA-23910 4712 ± 29 5371 P. cf. sylvestris6 Trunk Val06 S UBA-23908 5103 ± 39 5791 P. cf. sylvestris7 Trunk Val03 S – – – P. gr. sylvestris8 Wood fragment Val21 1/0 – – – P. cf. sylvestris9 Wood fragment Val20 1/0.7 – – – P. gr. sylvestris10 Branch Val22 1/1.3 UBA-23911 5445 ± 30 6250 P. gr. sylvestris11 Trunk Val23 1/1.5 UBA-22236 5556 ± 46 6349 P. cf. sylvestris12 Wood fragment Val24 1/1.9 – – – P. gr. sylvestris13 Wood fragment Val26 1/3 – – – P. cf. sylvestris14 Trunk and wood fragments Val28 1/1 UBA-22238 5574 ± 53 6370 P. gr. sylvestris15 Trunk Val04 S UBA-19751 5777 ± 33 6577 P. cf. sylvestris16 Trunk Val30 S – – – P. cf. sylvestris17 Wood fragments Val31 S – – – P. gr. sylvestris18 Branch Val32 S UBA-22239 5780 ± 36 6580 P.cf. sylvestris19 Trunk and wood fragments Val09 S UBA-22247 5832 ± 58 6625 P. gr. sylvestris20 Trunk and wood fragments Val05 S UBA-22235 5821 ± 37 6632 P. gr. sylvestris21 Trunk Val07 S UBA-23909 5927 ± 33 6735 P. cf. sylvestris22 Trunk and wood fragments Val02 S UBA-23907 6175 ± 32 7074 P. cf. sylvestris23 Trunk and wood fragments Val01 S UBA-22234 6547 ± 44 7470 P. cf. sylvestris24 Wood fragments Val90 S – – – P. gr. sylvestris25 Trunk Val80 S – – – P. cf.sylvestris26 Trunk Val81 6/0.5 UBA-23913 7230 ± 34 8024 P. cf.sylvestris27 Wood fragments Val82 6/2 – – – P. gr. sylvestris28 Wood fragments Val83 6/2.3 – – – P. gr. sylvestris29 Wood fragments Val84 6/2.9 – – – P. gr. sylvestris30 Wood fragments Val60 4/0.6 – – – P. gr. sylvestris31 Wood fragments Val61 4/0.9 – – – P. cf.sylvestris32 Wood fragments Val62 4/1.2 – – – P. cf.sylvestris33 Wood fragments Val63 4/1.8 – – – P. cf.sylvestris34 Branch Val64 4/2,1 UBA-23912 7277 ± 42 8093 P. gr. sylvestris35 Wood fragments Val65 4/3.5 – – – P. gr. sylvestris36 Wood fragments Val66 4/4 UBA-22242 7384 ± 44 8246 P. gr. sylvestris37 Wood fragments Val84 6/2.9 UBA-22244 7446 ± 44 8273 P. gr. sylvestris38 Vertebra B1 3/2.2 UBA-23915 5638 ± 37 6406 Bos primigenius39 Bark Val50 3/2,2 – – – Pinus sp.40 Wood fragments Val51 3/3.6 UBA-22241 7529 ± 40 8355 Pinus sp.41 Wood fragments Val27 1/3.1 UBA-22237 7756 ± 44 8515 P. gr. sylvestris42 Wood fragments Val40 2/1.8 – – – P. gr. sylvestris43 Wood fragments Val41 2/2.4 – – – P. gr. sylvestris44 Metacarpal B2 2/2.4 – – – Bos primigenius45 Wood fragments Val42 2/2.6 – – – P. gr. sylvestris46 Wood fragments Val43 2/3.6 – – – P. gr. sylvestris47 Wood fragments Val44 2/4.2 UBA-22240 7998 ± 48 8855 P. gr. sylvestris48 Wood fragments Val70 5/3.7 UBA-22243 8890 ± 55 10025 P. cf. sylvestris

814 M. Génova et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 441 (2016) 811–822

Peraza (1964) and Schweingrüber (1990). The samples were also com-pared to those in reference collections of extant and fossil wood belong-ing to the Universidad Politécnica de Madrid (Spain). Diagnosis wasperformed by means of a combination of qualitative and quantitativefeatures. We calculated means for features such as height, shape andarrangement of the dentations present in the ray tracheids of thecross-field pits after taking 20 measurements in different parts of thewood. All anatomically studied samples are housed in the UniversidadPolitécnica de Madrid (Spain).

Some authors indicate that identification at the species level of woodfrommountain Iberian pines (including Pinus nigra Arnold, P. sylvestris L.and P. uncinata Ramond ex DC.) is difficult and sometimes impossible(Schweingrüber, 1990; Carcaillet and Vernet, 2001). Nonetheless, otherresearchers (Greguss, 1955; Jacquiot, 1955; Peraza, 1964) indicate theexistence of diagnostic features that can be used to this end, especiallywhen youngwood is avoided (which can exhibit a great deal of intraspe-cific variation) and the macroremains are well preserved (Mutz et al.,2004; Figueiral and Carcaillet, 2005). The excellent state of preservationof our samples and the fact they were very thick enabled identificationsto be made.

3.2.3. Dendrochronological analysisFor the dendrochronological analysis we selected themacroremains

that had an appropriate number of rings (14 trunks and two branches)and cut a section in each of them. After surface preparation (sanding),the ring widths were measured on several radii of the sample (3 to 9,depending on shape and size); more radii were measured in irregularlyshaped or greater sections. Ring-width measurements were taken to anaccuracy of 1/100 mm with a digital LINTAB positioning table connectedto a stereomicroscope and TSAPWin software (Rinn, 2003).We employedCOFECHA (Holmes, 1992) and TSAPWin software to cross-date and corre-late the chronologies. The series of each radius and section were cross-dated and averaged in an individual chronology corresponding to eachmacroremain (Fig. 3).

A total of 13 of the macroremains dendrochronologically analysedhad previously been radiocarbon dated and the dating had been cali-brated. For each of the macroremains we applied this calibrated dateto the final datumof the individual tree ring growth sequence (the clos-est one to the bark) and we successively dated the rest of the values.Oncewe had dated all the individual sequences, we studied the correla-tions between those of the closest radiocarbon age to adjust the dating

3002902802702602502402302202102001901801701601501401301201101009080706050403020100

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Val5. 9 rays measured, maximum radius:19 cm,

258 tree rings, mean width ring: 0,72 mm

Tree ring number

Pith

Outer ringTre

e rin

g w

idth

(m

m x

100

)

Fig. 3.Anexample of themacroremains dendrochronologically analysed (VAL05), inwhich 9 radii weremeasured and the growth ring sequencesmeasuredwere synchronised in order tocreate an average sequence.

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to the sequences selected as a reference for each period and to obtainthe dendrochronological age (Bradley, 1999; Nicolussi et al., 2009).Likewise, we analysed the individual mean chronologies that had notbeen radiocarbon dated, studying the possible temporal range of eachone. When the dendrochronological statistical indicators were suffi-ciently reliable, we designed composite chronologies.

3.3. Bones

We analysed two bones from a bovid, one metacarpal and one verte-bra. The metacarpal was found in test hole no. 2 at a depth of 2.4 m. Thevertebra was found in test hole no. 3 at a depth of 2.2 m. Both of themwere in a good state of conservation. Due to the low collagen content ofthe metacarpal, we only dated the vertebra, using AMS (Queen's Univer-sity, Belfast) calibrating it with the Radiocarbon Calibration ProgramCALIB 7.0.0 (Stuiver and Reimer, 1993). The samples were identified atthe Archaezoology laboratory of the Universidad Autónoma de Madridby the palaeontologist Arturo Morales Muñiz.

4. Results

4.1. Dating

Twenty-two subfossil wood samples were radiocarbon dated; onehalf of them was collected from the surface and the remaining onesfrom the test holes (Fig. 2). In Table 1 the macroremains were orderedchronologically according to calibrated age, which ranges from 83 to10,025 cal yr BP. This table also includes the values corresponding tothe bone dated. Although two of the samples are very recent (225 to83 cal yr BP, respectively), most of them date approximately from10,000 to 5000 cal yr BP: the first half of the Holocene, from the Borealperiod to the Atlantic one. However, there is not an even distribution ofsamples, for example the 48% of the samples date between 7500–6000 cal yr BP, including both the samples appearing on the surfaceand those found at shallow depths (between 1 and 1.5m). Additionally,the vertebra (located at a depth of 2.2 m) is also in that age range. The

rest of the buried wood macroremains (36%) are older, up to a maxi-mum of just over 10,000 cal year BP.

4.2. Wood identification

The microscopical analysis performed on 46 samples exhibited thefollowing anatomical features:

Description. Transverse section: homoxylous wood with easilyidentifiable growth rings (Fig. 4B). Polygonal tracheids in cross sec-tion; mean diameter 20 μ. These tracheids are occasionally foundhighly compressed as a result of taphonomic distortion processes(Fig. 4A). Physiological longitudinal resiniferous channels preferen-tially located in the summer wood and transition zones. Thin-walledepithelial cells that come away during preparation of thin slides. Radi-al section: cross-fields fromparenchyma cells to tracheidswith one, orrarely two, fenestriform pits (Fig. 4C). Ray tracheids generally with noisolated dentations, normally acute (Figs. 4Ca, 4 Da); length of dentatewalls varies from 6 to 10 μ; these tooth-likewall thickenings are occa-sionally found connectedwith other dentations of the opposite side inthe cell lumen. Tangential section: areolate tracheid pits in uniseriaterows (Fig. 4E). Heterogeneous woody rays uniseriate or pluriseriate,the latter showing physiological resiniferous canals. Average heightof rays 5 to 9 cells (Fig. 4F).Identification. These anatomical features are characteristic of theP. sylvestris group, including P. sylvestris L., P. nigra Arnold andP. uncinata Ramond ex DC. (Greguss, 1955; Schweingrüber, 1990).The set of characteristics such as the lack of remains of epithelialcells after the preparations and specially, the tooth-like wall thicken-ings, which are pointed, not isolated and occasionally leaving colum-nar formations, let us to identify our samples as P. sylvestris L.(Greguss, 1955; Jacquiot, 1955; Peraza, 1964). Nonetheless, the afore-mentioned discrepancies regarding the reliability of the diagnosiswithin these species put forward by others authors (Schweingrüber,

Fig. 4.A, Val-23. Transversal section. Poligonal tracheids compressed due to lithostatic pressure. Scale bar: 20 μ. B, Val-23. Transversal section.Well-defined growth rings with resiniferouscanals in the late wood. Scale bar: 250 μ. C, Val-1. Radial section. Cross-fieldswith one or two fenestriformpits. Scale bar: 80 μ. D, Val-1. Radial section. Conspicuous and non isolated tooth-like wall thickenings. Scale bar 40 μ. E, Val-1. Tangential section. Areolate tracheid pits in uniseriate rows. Scale bar 40 μ. F, Val-28. Tangential section. Uniseriate ray. Scale bar: 10 μ.

816 M. Génova et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 441 (2016) 811–822

1990; Carcaillet and Vernet, 2001) suggest to assign tentatively oursamples to the taxon P. cf. sylvestris.

4.3. Tree-ring chronologies

The 16 macroremains selected for dendrochronological analysiscome from tree trunks, with the exception of two of them, involvingbranches (Table 1). We measured 18,542 tree rings grouped into 93growth series. The values of intercorrelation among the differentsequences from each sample are high, and we obtained 16 individualaverage floating chronologies. The maximum number of rings from theindividual chronologies ranged from 95 to 429, and 73% had over 200tree rings. The vast majority of these remains does not present sapwoodor bark, and are therefore most likely from older trees.

Inmany of the samples, average ringwidth is very low, ranging from0.19 to 1.09mm.Nonetheless, in all cases they correspond to heartwoodrings, because only one of the samples presents bark (VAL80), but withsuch deformed sapwood rings that they were impossible to measure.The general growth patterns and statistical indicators are habitual forP. sylvestris in this geographical area (Richter et al., 1991; Génovaet al., 1993; Génova, 2000, 2012), exceptions being the chronologies ofVAL09, corresponding to a samplewith two piths, VAL23with notewor-thy release in the central zone, and VAL22, a very old branch, withdecrease followed by release in the central zone.

We tested the synchronisation of the individual chronologies of sim-ilar calibrated age, taking as a reference the longest chronology in eachgroup. We also tested the synchronisation of the individual average

sequences of the 3 macroremains not radiocarbon dated. Contrastingthe radiocarbon calibrated age and the dendrochronological age, themaximum difference obtained was 226 years, which falls within therange of ages calibrated by 2 σ, and we therefore consider it to bequite reliable.

With the concordant series we designed 4 composite chronologies(Table 2). We designed composite chronology 1 by successfullysynchronising 2 individual chronologies; Composite chronology 2 cor-responds to samples located in test hole no. 2, which were reliablysynchronised amongeach other. Furthermore, other individual chronol-ogies, based upon macroremains found on the surface, design Compos-ite chronology 3. Composite chronology 4 was likely obtained from onesingle trunk, as a result of disarticulation processes; both sequences pre-sented a high level of correlation between growth values, although thesamples do exhibit different state of preservation. The remaining indi-vidual chronologies are extended over other temporal ranges and/orwere not synchronised well with other chronologies, and these weretherefore kept as individual floating chronologies (Table 2 and Fig. 5).

The chronologies cover almost 3000 years (approximately between8200 and 5800 cal yr BP). In the period 6978–6349 cal yr BP (630years) there is greater replication, with over 9 individual chronolo-gies dated (60% of the dendrodated samples), corresponding to thelarger-sized and better-conserved remains and which were mostlygrouped within composite chronologies 2 and 3. However, thesecomposite chronologies were not reliably correlated between eachother, or with chronologies VAL32 and VAL07, despite being situatedwithin coinciding temporal ranges.

Table 2Samples analysed with dendrochronological methods.*: macroremains found buried between 0.5 and 1.5 m.#CC: identification of composite chronologies, IT: intercorrelation, MNtree-rings: maximum number of rings.

ID laboratoryreference

Max radius(cm)

MNtree-rings

Mean tree-ringwidth

Std dev Cal BP Age+ DendrochronologicalAge

Cal BP age–dendroage

#CC/IT Floatingchron. BP

No. of years

VAL08UBA-23910

11.5 364 0.34 0.13 5371 5734–5371 – 1/0.64 5752–5371 382

VAL03 13 350 0.38 0.18 – 5752–5402 (Ref VAL08) –VAL06UBA-23908

8 304 0.26 0.08 5791 6094–5791 – – 6094–5791 304

*VAL28UBA-22238

9 240 0.42 0.21 6370 6589–6349 (Ref VAL23) 21 2/0.41 6781–6349 433

*VAL23UBA-22236

12 429 0.27 0.17 6349 6781–6349 –

*VAL22UBA-23911

7 347 0.19 0.09 6250 6719–6367 (Ref VAL23) −117

VAL32UBA-22239

9 375 0.25 0.17 6580 6954–6580 – – 6954–6580 375

VAL04UBA-19751

17 254 0.89 0.45 6577 6924–6671 (Ref VAL05) −94 3/0.73 6984–6632 347

VAL05UBA-22235

19 282 0.79 0.34 6632 6913–6632 –

VAL30 10.5 95 1.09 0.35 – 6906–6812 (Ref VAL05) –VAL09UBA-22247

10 128 0.77 0.26 6625 6984–6851 (Ref VAL05) −226

VAL07UBA-23909

9 128 0.88 0.28 6735 6862–6735 – – 6862–6735 128

VAL02UBA-23907

11.5 237 0.52 0.20 7074 7310–7074 – – 7310–7074 237

VAL01UBA-22234

9.5 180 0.54 0.25 7470 7649–7470 – 4/0.70 7649–7399 251

VAL80 11.5 245 0.45 0.22 – 7643–7399 (Ref VAL01) –*VAL81UBA-23913

8 133 0.63 0.23 8024 8156–8024 – – 8156–8024 133

817M. Génova et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 441 (2016) 811–822

4.4. Identification of bones

The good state of conservation of the 2 bones found (onemetacarpalandonevertebra) enabled us to be attributed to the genus Bos. Anatomicanalysis of the metacarpal indicates that it is a right-hand metacarpalwhose surface presents various striations that would appear to corre-spond to dragging marks from the diagenetic phase. This bone is likelyfrom a sub-adult male. Its morphometric data are the following: maxi-mum length: 23.8 cm; proximal width: 7.55 cm; minimum diaphysiswidth: 4.1 cm and distal width: 7.7 cm. The anatomical study conductedwith the reference collection from the Archaezoology laboratory ofthe Universidad Autónoma de Madrid and the Consejo Superior deInvestigaciones Científicas, reveals that these two remains correspondto the taxon Bos primigenius Boj. (Arturo Morales, pers. com.) (Fig. 6).

8200 7800 7400 7000

1 2 1

TreeRingwidth(mm)

Fig. 5. Dendrochronologies obtained at the Valdojos site. a) Raw chronologies: individual chrranges of the floating chronologies, with an indication of the number of average sequences in

5. Discussion

5.1. Relevance of Valdojos site in the Central System Range and geobotanicalimplications

5.1.1. Occurrence of Pinus sylvestris in the Ayllón Massif in the first half ofthe Holocene

Despite the numerous palaeobotanical studies addressing the CentralSystem Range over the last 50 years, well over one hundred (López-Sáezet al., 2013), there is still little palaeobotanical information for thefirst halfof the Holocene and for some areas of the mountain range.

This is the case of the Ayllón Massif. For the first time in the easternzone of the Central System Range, the Valdojos site provides vegetationdata for the time interval 10,025–5371 cal yr BP. This fact therefore

6600 6200 5800 5400

9 1 2B

A

onologies in a lighter colour and composite chronologies in a darker colour. b) Temporaleach range.

Fig. 6. Left-hand side, right metacarpal in anterior view. Right-hand side: lumbar vertebra in anterior view.

818 M. Génova et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 441 (2016) 811–822

demonstrates the continuous presence of forests of P. cf. sylvestris at analtitude of over 1320 m asl. These data, which are completely newwithregard to age and taxonomic determination, cannot be compared to anyother, as all other research addressing the area presents chronologiesthat are generally much more recent and taxonomically less accurate.

Indeed, the oldest data for the zone to date are from the pollen studyof the Pelagallinas peat bog (sierra de Alto Rey, 1340m asl; Fig. 7), withtwo datings (3980± 90 and 2400± 40 years BP) reflecting the vegeta-tion in the last fourmillennia (Franco-Múgica et al., 2001b). Other stud-ies exist that provide more recent palaeobotanical information, such asthe Somolinos (2410 ± 401385 ± 30 years BP; Currás et al., 2012) andPico del Lobo (1170 ± 80 years BP; Gil-García et al., 1994), whereasother studies lack absolute datings and correspond to short sequencesthat are also probably very recent (Ruiz del Castillo, 1993; Gil-Garcíaet al., 1994). Our research therefore provides new data on thepalaeovegetation for the first half of the Holocene, the whole of Borealand Atlantic periods, totally unknown to date for the Ayllón Massif.

Although only one taxon was found, the presence of P. cf. sylvestris inthe area is relevant, because it helps to resolve the controversy regardingpre-anthropic vegetation in Ayllón, particularly that of the Alto Rey andPela mountains and the vicinity of Campisábalos. The presence of ancient

A

Fig. 7.A. Sites cited in the text with palaeobotanical information for thefirst half of theHoloceneGarganta del Villar (Gredos); 5. CuerpodeHombre (Béjar); 6. Hoyos del Espino (Gredos) 7. Baterpaper). B. Location of the sites cited in the text in the Ayllón Massif. A. Pelagallinas; B. Laguna d

pine forests in the zone had been demonstrated by pollen cores inthese zones. Thus, in the above mentioned Pelagallinas sequence,Pinus dominates ca 4000–2400 years BP, reaching percentages of 50%and accompanied by up to 30% of Betula (Franco-Múgica et al., 2001b).Similarly, in the study conducted in the Galve de Sorbe peat bog, closeto the Valdojos site (see Fig. 7), the authors highlight the fact that the pol-len percentages of Pinus are higher than those of other tree taxa through-out thewhole profile (Hernández-Vera and Ruiz-Zapata, 1984). Likewise,Somolinos sequence exhibits high percentages of pine forests (N60%) ca870–540 cal years BC.

5.1.2. Is Pinus sylvestris native to the Eastern Central System Range?The Iberian Peninsula has been subjected to intense anthropic action

for the last few millennia, which has given rise to profound changes inthe vegetal landscape, as an intense deforestation over vast areas. TheCentral SystemRange has not escaped this process and has also sufferedthe impact of human activity. Thus, there has been a great reduction ofthe area occupied by trees (pine, oak, beech forests, etc.) and conse-quently the extension of bush and herbaceous cover. Moreover, in thesecond half of the XX century, intense afforestation was conducted inSpain (Groome, 1990; Gómez Mendoza, 1992; Carrión et al., 2000b,

B

. 1. Charco da Candieira (Estrela); 2. El Maíllo (Francia); 3. Garganta del Trampal (Béjar). 4.na (Gredos); 8.Hoyocasero (Gredos); 9. Rascafría (Guadarrama); 10. Valdojos (thepresente Somolinos; C. Galve de Sorbe; D. Pico del Lobo; E. Valdojos (the present paper).

819M. Génova et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 441 (2016) 811–822

2010; Valbuena-Carabaña et al., 2010). One of themost commonly usedspecies was P. sylvestris, and 600,000 ha of this taxon were planted be-tween 1940 and 1993 (Valbuena-Carabaña et al., 2010). One of the ter-ritories afforested with a large amount of this species is the CentralSystemRange. In theAlto Sorbe basin,where the Valdojos site is located,this afforestation programme was also implemented as from 1948, andinvolved P. sylvestris and Pinus pinaster (Fernández-Muñoz, 2002).

Due to these deforestation and afforestation processes, the currentlandscape of the Central System Range comprises two types of forest:those resulting from recent afforestation and others that existed previ-ous to these implementations and for which historical documentationexists (Montoya Ramírez, 1992; Calvo Sánchez, 2003).

In parallel to thismass afforestation process, in thefinal third of theXXcentury the idea spread among Spanish botanists and forestry engineersthat many of the formations dominated by species of Pinus on the IberianPeninsula were of anthropic origin. Among these, most of P. sylvestrisforests in the Central System Range, which were interpretedresulting from older afforestation in the potential ranges of other species(Martínez-García and Costa Tenorio, 2001; Martínez-García, 2002).Within the scientific scope, the idea that most of the current Iberianpine forests are artificial formations has meant that the vast majority ofpine forests have been ignored or underestimated in studies on the realor potential vegetation in the territory. This, for instance, has occurredin the eastern zone of this mountain range where the Valdojos site islocated (De la Fuente, 1985; Monje-Arenas, 1987; Peinado-Lorca andMartínez-Parras, 1987; Rivas-Martínez, 1987).We shouldmention, how-ever, that some phytosociological studies on the upper zones of Pelamountains have recently recognised communities of Scots pine on litho-sols or on very steep shady slopes. According to these studies the decidu-ous species are at a clear competitive disadvantage therein (De la Cruzand Peinado, 1996; Rivas-Martínez et al., 2001, 2011).

The data obtained in the present research therefore clearly support thenatural and ancient origin of the P. sylvestris forests in the eastern sector ofthe Central System Range, as they unequivocally demonstrate the presenceof this taxon in the first half of the Holocene (approx. between 10,000 and5000 years BP). Furthermore, on considering the ecological characteristics ofthe territory, the hypothesis is supported that the pollen sequences of Pinusobtained from the nearby cores at Pelagallinas and Somolinos (Franco et al.,2001b; Currás et al., 2012), of an approximate age of 4000 and 2400 yearsBP respectively, also could correspond to P. sylvestris. Moreover, this hy-pothesis is coherent with the abundant historical information datingfrom the XIV century (Montoya Ramírez, 1992), which indicates anabundance of pine forests in vast areas of the eastern edge of the CentralSystemRange previous to the initial afforestations half-way through theXX century (Fidalgo Hijano, 1987; Martínez-García, 1999, 2002;Martínez-García and Costa Tenorio, 2001).

5.1.3. The Scots pine in the Central System Range from the early to the mid-Holocene

In the Iberian Central System Range few palaeobotanical studiesprovide data on the vegetation during the first half of the Holocene,

Table 3Macroremains found in the Central SystemRange in the Lateglacial and Early tomid-Holocene rages expressed in cal yr BP.

Macroremain N Diagnosis Age

Needle 1 P. cf. sylvestris Lateglacialca 14,060–12,850

Stomata – P. cf. sylvestris Lateglacialca 14,060–12,850

Charcoal – P. gr. sylvestris Early Holoceneca 10,550–9800

Wood 1 P. gr. sylvestris Mid-Holoceneca 6415

Wood 46 P. cf. sylvestris and P. gr. sylvestris Early and Mid-Hca 10,025–5371

and inmost cases they analyse pollen sequences; very little informationexists on macroremains (Fig. 7, Table 3).

Thus, in the Western sector of the Central System (Estrela, Franciaand Béjar mountains), the presence of Pinusmay be detected since theTardiglacial period, ca. 14,800 cal yr BP, showing the sequences ofCharco de Candieira, Maillo and Garganta del Trampal, a constant de-crease and relatively low values of Pinus during the first half of the Ho-locene (Fig. 7; Ruiz-Zapata et al., 1989; Atienza et al., 1990; Van derKnaap and Van Leuwen, 1997; Connor et al., 2012; Morales-Molinoet al., 2013). Regarding macroremains, one needle and stomata collect-ed at Charco de Candieira have been attributed to P. cf. sylvestris and anumber of charcoals from the Maillo peat bog have been related withP. gr. sylvestris/nigra and P. pinaster/pinea (Table 3; Van der Knaap andVan Leuwen, 1997; Morales-Molino et al., 2013). On the other hand, amore consolidated pine forest, with a dating close to the base of5160± 40 years BP can be detected in the sequence of Cuerpo de Hom-bre (Ruiz-Zapata et al., 2011).

The Gredos and Guadarrama mountains also have very few palyno-logical sequences to provide information for the first half of the Holo-cene. In this region, the presence of pollen of Pinus sylvestris-type hasbeen highlighted in the Garganta del Villar sequence and the Baternacore (Dorado-Valiño, 1993; López-Sáez et al., 2009, 2013). These sites,including the Hoyos del Espino peat bog (Franco-Múgica, 2009), inwhich a trunk attributed to P. gr. sylvestris has been found (Génovaet al., 2009), reveal a greater predominance of Pinus than the previousones in the western sector. Likewise, the Rascafría pollen core (seeFig. 7), (ca. 8410 ± 250 years BP to present day) shows the presenceof P. cf. sylvestris throughout practically the whole Holocene, the treepollen exceeding 90% in the interval between 8410 and 3700 years BP(Franco-Múgica and García-Antón, 1994; Franco-Múgica et al., 1998).

Taken into account the previous data, we can state that pine forests,probably related with P. sylvestris, were significant in the vegetal land-scapes during the first half of the Holocene along thewestern and centralsectors of the Central SystemRange. Now, the newdata from theValdojossite let us to complete this general overview and we can conclude thatalso in the eastern sector of the Central System Range the scots pinewas widespread over the first half of the Holocene.

5.2. Palaeodendrochronological inferences at Valdojos site

Within the European framework, sites with dendrochronologicallydated fossils are relatively common (e.g. Leuschner et al., 2002;Nicolussi et al., 2009; Kolář and Rybníček, 2011; Kaiser et al.,2012); in some of them being Pinus sylvestris the more commontaxon (Miramont et al., 2000; Eronen et al., 2002; Gunnarson,2008). In southern Europe, however, themuch less favourable conditionsfor the conservation of fossil macroremains have hindered the establish-ment of palaeodendrochronologies.

To date, the southernmost European sites with dendrochronologicallystudied woods of Pinus sylvestris group are found in the west of Spain'scentral system -the Gredos mountains- (Rubiales et al., 2007; Génova

elated to P. cf. sylvestris or P. gr. sylvestris. N: number of macroremains found. Age: absolute

Site References

Charco de Candieira(Serra da Estrela)

Van der Knaap and Van Leeuwen (1997);Connor et al. (2012)

Charco de Candieira(Serra da Estrela)

Van der Knaap and Van Leeuwen (1997);Connor et al. (2012)

El Maíllo(Francia)

Morales-Molino et al. (2013)

Hoyocasero(Gredos)

Rubiales and Génova (2015)

olocene Valdojos(Ayllón)

The present paper

820 M. Génova et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 441 (2016) 811–822

et al., 2009; Rubiales and Génova, 2015). In different sites a total of 23floating chronologies was obtained between 6415 and 762 cal yr BP(Rubiales and Génova, 2015), whereas at the Valdojos site, the 16 chro-nologies obtained range from 8156 to 5371 cal yr BP. Thus, the informa-tion from this new site provides a 75% increase in the number offloating fossil chronologies from the centre of the Iberian Peninsula withan increase of 1750 years in the time record. Furthermore, at Valdojosthe average of the maximum number of rings per sample is around 261years, over twice asmuch as the remains located in theGredosmountains(Rubiales and Génova, 2015). The exceptional features of the Valdojosmacroremains enabled us, for the first time in Spain and in southernEurope, to successfully crossdate some of the floating chronologies andto create 4 composite chronologies. Thus, we can highlight the fact that,in the context of southern Europe, the Valdojos site is highly exceptionalfrom the dendrochronological point of view, and is extraordinarily richdue both to the high number of large remains found and studied and tothe number, quality and scope of the floating chronologies obtained.Consequently, following our research at Valdojos, there is now a total of39 floating chronologies for the whole Central System Range, coveringapproximately the period 8156–762 cal yr BP (almost 7500 years).

Although the data from Valdojos are not sufficiently abundant toestablish palaeoecological conclusions, it should be pointed out that forthe whole site the most recent fossil macroremains (6700–5300 cal yrBP) present the narrowest rings (Table 2 and Fig. 5). This means that,approximately 6700 years ago in this sector of the Iberian Central System,environmental changes might have occurred affecting the growth of thetrees. Among others we can highlight a temperature decrease, coincidingwith a phase of glacier advances (Nicolussi et al., 2009). Another possibleinterpretation of the poor growth rates at Valdojos in this final stagemight involve a hypothetical increase in detritic accumulation, becauseat other sites containing fossil macroremains from alluvial and colluvialdeposits, this factor has been associated with periods of abrupt growthdecrease (Miramont et al., 2000).

The end of the functioning of the sedimentation system at Valdojosmight coincide with the age of the most recent fossil macroremains(approximately 5300 cal yr BP). This also occurs in the Middle Durance(Southern Alps, France; Miramont et al., 2000), or in the extensivedendrochronological study conducted in the Eastern Alps (Nicolussiet al., 2009). In both cases, very few trunks of fossilised trees werefound as from 6000 cal yr BP, due to the fact that this was the start of

1

7

Fig. 8.Mesolithic and Neolithic sites cited in the text and presenting aurochs. 1. Cueva de MazFuente Flores. 7. Valdojos (the present paper).

an unfavourable period for burial and conservation. Nicolussi et al.(2009) provide further detail and point out that for the period between5650 and 5250 cal yr BP, fewer remains have been found, as this timecoincided with known periods of glacier advances.

5.3. Bos primigenius Boj. in the Iberian Peninsula in the first half of theHolocene

The aurochs (Bos primigenius) was a species with a broad range ofdistribution during the Quaternary, from India to north Africa andEurope; its disappearance has been linked to habitat destruction andoverhunting, and it was last detected in Poland in the year 1627 AD(Van Vuure, 2005). It reached the European continent from Africa atthe start of the Pleistocene (Martínez-Navarro et al., 2007), althoughthe Iberian Peninsula, as well as the Italic Peninsula, might have consti-tuted refuge areas for this taxon during this period (Mona et al., 2010).The oldest citation for the Peninsula refers to approximately 700 ka(Estévez and Saña, 1999), and its presence was established during themid-Pleistocene and particularly the upper Pleistocene at differentsites distributed throughout the Peninsula (e.g. Arsuaga et al., 2012;Burjachs et al., 2012; Évora, 2013). Most occurrences of the taxon onthe Peninsula are from the Holocene, as occurs for Europe, a factthat is associated with the improved postglacial climatic conditions,which favoured its expansion (Wright, 2013). For the first half of theHolocene, this taxon has been cited in a small number of Iberian sites(Fig. 8). These are: Cueva de Mazaculos II (10013–7503 cal BC;Arroyo and Morales, 2009), Mendandia (6550–4490 BC; Castaños,2005), La Sierra de Gibijo (6505–5927 cal BC; Altuna, 1974), Cuevade Chaves (4820–4170 cal BC; Castaños, 2004) and Arenaza (Meso-lithic; Arias Cabal and Altuna, 1999). Also cited and assigned to theNeolithic–Calcolithic are the Fuente Flores (Cabanilles and Valle,1988) and La Renke (Altuna, 2001) sites. Therefore, in sites on thePeninsula from between the Mesolithic and the Neolithic, Valdojosis to date the only one presenting aurochs macroremains in the Cen-tral System Range and the surrounding area of the centre of thePeninsula.

With regard to its habitat, according to Van Vuure (2005) the abun-dant findings of aurochs in the Netherlands in river valleys suggest thatit inhabited flatlands near rivers. Hall (2008) has corroborated thisthesis by means of analysis of numerous sites dated as Late Pleistocene

42

5

3

6

aculos II. 2. La Sierra de Gibijo 3. Arenaza. 4. La Renke y Mendandia. 5 Cueva de Chaves. 6.

821M. Génova et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 441 (2016) 811–822

and Postglacial in Britain, thus confirming the Van Vuure's thesis that theaurochs inhabited riverine flatlands. Because of its location in a valleybottom, close to a riverbed, the Valdojos site could have presented similarenvironmental conditions to those described as a preferential habitat forthis species.

6. Conclusions

The results obtained from the analysis of the macroremains found atValdojos provide highly relevant data for palaeobotanical interpretationof the eastern sector of the Central System Range throughout the Holo-cene. They provide accurate information that enables us to reconstructthe vegetal landscape of the territory. The taxon P. cf. sylvestris has beenidentified as one of the principal species in these forests during the firsthalf of theHolocene,which appears to have formed stable and continuousforests. This hypothesis seems to be supported by the ecological charac-teristics of the area and by the abundant historical information.

From thedendrochronological perspective the Valdojos site is totallyexceptional within the southern European and Iberian context, provid-ing a set of extensive floating chronologies of great palaeoecologicalinterest for the first half of the Holocene.

Finally, the remains found of Bos primigenius enlarge the scantcatalogue of localities presenting this species between the Mesolithicand the Neolithic on the Peninsula, Valdojos being to date the only siteof aurochs in the centre of the Peninsula in this age.

Acknowledgments

The present paper is dedicated to the memory of our friend andcolleague Rufino García, who passed away in 2011 and who initiatedthis research with us. We are grateful to Carlos Morla for his continuousassistance. We also wish to thank Arturo Morales Muñiz for his help inthe identification of the bones. We verymuch appreciate the informationreferring to the site and the support providedby Joaquín Castelo, GregorioCerezo and Juan Pablo Santo Domingo deMarcos. Our thanks are also dueto the government of the Castilla-La Mancha region and to the land-owners. This research was supported by the Project DINECOFOR(CGL2011-27229).

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