Global Change Biology (1999) 5, 201–212
Crop water availability in early agriculture: evidence
from carbon isotope discrimination of seeds from a tenth
millennium BP site on the Euphrates
J . L . A R A U S , * A . F E B R E R O , * M . C A T A L A , † M . M O L I S T , ‡ J . V O L T A S § and
I. ROMAGOSA§
*Unitat de Fisiologia Vegetal, Universitat de Barcelona, Spain, †Facultat de Humanitats. Universitat Pompeu Fabra. Spain,
‡Departament d’Antropologia Social i Prehistoria, Universitat Autonoma de Barcelona, Spain §Area de Conreus Extensius,
Centre R 1 D UdL – IRTA, Lleida, Spain
Abstract
The analysis of carbon isotope discrimination (∆) in crop plant remains from archaeological
sites may help to assess water availability for early agriculture. This study presents the
analysis of ∆ in seeds of naked wheat (Triticum aestivum/durum), lentil (Lens orientalis/
culinaris), and flax (Linum sp.) found at the archaeological site of Tell Halula in the valley
of the Middle Euphrates (Syria). This Neolithic site is the oldest in this region of the Fertile
Crescent where the cultivation of domesticated plants has been reported, with seed remains
ranging from 9550 to 8465 BP. Most of the seeds analysed showed ∆ values greater than
16 ‰, reaching 20 ‰ for some samples of flax. For wheat, ∆ values were much higher
than those reported in present-day (1996) durum wheat crops cultivated under rainfed
conditions in north-west Syria under environments with somewhat higher rainfall than
Tell Halula. Similarly, grains of present-day (1997) barley cultivated in the archaeological
site also showed lower values than those found in archaeological kernels. An empirical
relationship between ∆ of mature kernels and total precipitation (plus irrigation where
applicable) from heading to maturity (r2 J 0.82, n J 11) was established for durum wheat,
currently cultivated in different environments of the Mediterranean basin. The resulting
relationship was applied to the data on ∆ of wheat fossil kernels from Tell Halula to
estimate the accumulated water inputs during the time (about 6 weeks) the kernels were
produced. Calculated water inputs for wheat during early agriculture were (over 110 mm)
at least 5 times higher than current-day rainfall accumulated in Tell Halula during the
same phenological period. These results strongly suggest that early agriculture wheat was
cultivated at Tell Halula under much wetter conditions than are currently to be found in
the area. The presence of flax and its very high ∆ values also support this conclusion.
Whether such humid conditions during cultivation were due to moister conditions prevailing at this time, by planting in alluvial areas or by irrigation works is discussed.
Keywords: early agriculture, flax, lentil, stable carbon isotope discrimination, water regime, wheat
Abbreviations: ∆, stable carbon isotope discrimination; δ13C, ratio of 13C/12C relative to PeeDee
belemnite standard; pi/pa, ratio of intercellular to atmospheric partial pressure of CO2; BP, before
present; L-N, Late Neolithic; M- and L-PPNB, Middle and Late Pre-Pottery Neolithic B (PPNB).
Received 11 November 1997; revised version received and accepted 9 February 1998
Introduction
The environmental conditions prevailing when agriculture was first developed in the Old World, in the Fertile
Crescent (Near East) during the early Holocene, are
Correspondence: J.L. Araus, e-mail josel@porthos.bio.ub.es,
fax 134/ 34112842
© 1999 Blackwell Science Ltd.
somewhat obscure. Although recent data on climatic
conditions are more precise chronologically (Baruch &
Bottema 1991; Moore & Hillman 1992) and can explain
the environmental setting during the transition from
hunter/gathering to farming communities, such data
are indirect and not conclusive (Hillman 1996). Present
palaeoclimatological and archaeological findings suggest
201
202
J . L . A R A U S et al.
a more humid environment was to be found in the Near
East at the birth of agriculture. However, much remains to
be discovered about the precise nature of the environment
and crop growing conditions (Zohary 1996; Hole 1998),
not least the crop water status during these crucial
millennia for which no reliable (direct) data are available
(Rossignol-Strick 1993).
For C3 plants, such as those crops first cultivated in
the Fertile Crescent, carbon isotope discrimination (∆) in
crop grains constitutes an integrated record of the ratio
of intercellular to atmospheric partial pressure of CO2
(pi/pa) and, thus, of the water status during the growth
of these grains (Farquhar & Richards 1984). For example,
in cereals the water regime during grain filling strongly
affects the ∆ values of mature kernels (Condon et al. 1987,
1992; Craufurd et al. 1991; Romagosa & Araus 1991; Araus
et al. 1997a,b). Decreased water availability (and increased
evapotranspiration) causes lower pi/pa and, thus, a
decrease in ∆ of grains because of the effects of these
environmental factors on stomatal conductance or photosynthetic capacity (Farquhar & Richards 1984; Condon
et al. 1992). Therefore, from the analysis of ∆ of grains it
should be possible, in principle, to infer water status
during grain filling (Araus et al. 1997a). In this context,
the measurement of ∆ from seeds found in archaeological
sites has been proposed as a method for evaluating the
water status at the time these crops were grown (Araus
& Buxó 1993; Araus et al. 1997a,b).
The beginnings of agriculture in the Old World seems
to be associated with cereal domestication. Indeed, even
in those case where experimental studies provide a
theoretical indication of a time-lapse between the first
attempts of cultivation and morphological domestication
(Hillman & Davies 1990; Willcox 1991, 1992), to date
cultivation occurring prior to morphological domestication has not been identified from plant remains found in
the Near East (Willcox 1996). In this context, the PrePottery (aceramic) Neolithic B (PPNB) site of Tell Halula
is the oldest archaeological site on the Euphrates at which
domesticated crops have been reported (Molist et al. 1995;
Willcox 1996; see also Hole 1998). Thus, levels from
the tenth millennium before the present (BP) at Halula
indicate the appearance of domesticated crops such as
naked wheat (Triticum aestivum/durum), emmer (Triticum
dicoccum) and barley (Hordeum vulgare) (Molist et al. 1995;
Willcox & Català 1996; Willcox 1996). The domestication
of these cereals went hand-in-hand with the introduction
of several companion plants to the Fertile Crescent. Most
common in the PPNB farming villages are the remains
of two pulses: lentil (Lens culinaris) and pea (Pisum
sativum); and of a single oil-and-fibre crop, flax (Linum
usitatissimum) (Zohary 1996). These companion crops
were very probably domesticated (and taken into cultivation) simultaneously with the wheats and barley, or
just a short time later (Zohary 1996), although in the
domestication of lentils this may have occurred before
any other crop (Ladizinsky 1987, 1989). Whatever the
case, as with cereals, domestication of grain legumes
would have only been possible only under cultivation
(Zohary 1989).
In the present study the ∆ of fossil seeds is analysed
to determine the water status of several crops (wheat,
lentil and flax) of the Neolithic crop assemblage grown
in Tell Halula. The period studied corresponds to the
first millennium of cultivation of domesticated plants at
this archaeological site.
Materials and methods
Archaeological site and plant material
Tell Halula is an archaeological site situated in the Middle
Euphrates region, Syria (Fig. 1). This site comprises (to
date) three periods: Middle and Late PPNB, and Late
Neolithic (pre-Halaf) and is being excavated by the
Universitat Autonoma de Barcelona. The present-day
natural vegetation in the region is a degraded steppe,
with a total annual rainfall of about 250 mm (see legend
in Fig. 1). At present the land above the valley floor is
extensively used for lamb and goat grazing and rainfed
cultivation of barley, whereas durum wheat and horticultural crops are only cultivated where supplementary
irrigation is available.
Samples of seeds of durum wheat [Triticum durum
Desf., including T. aestivum/durum (after van Zeist &
Bakker-Heeres 1982), lentil (Lens orientalis/culinaris), and
flax (Linum sp.) were used for stable carbon isotope
analysis (Fig. 2). They were found in a carbonized state
and were gathered in disparate fashion from domestic
fires, cooking ovens and room floors. Six stratigraphic
levels from the archaeological site were studied. Soil
samples were treated using a standard flotation tank
in the field with 0.3 mm (flotation) and 2.5 mm (wet)
sieves. Plant remains were then dried slowly before
transport and sorting of seeds. Material was compared
with modern reference material which had been
gathered from various locations in the Near East. In
order to characterize the weed plant assemblage associated with these early crops, determination of weed
plants from carbonized material recovered in the
same stratigraphic sequences was also performed.
Palaeobotanical determinations were performed at the
Institut de Prehistorie Orientale of the CNRS Jalès,
France (Willcox 1996; Willcox & Català 1996). The three
crop species considered in this study were present
throughout the stratigraphic sequence studied. The
chronology of archaeological samples, in years before
the present (BP), was based on stratigraphic dating and
© 1999 Blackwell Science Ltd., Global Change Biology, 5, 201–212
W A T E R AVA I L A B I L I T Y I N E A R L Y A G R I C U L T U R E A N D ∆
Fig. 1 Map of the location of the archaeological
site studied. Tell Halula is situated in the
Euphrates region (Syria) about 100 km east of
Aleppo and 30 km south-east of Memjib (a).
This site is on the west river bank, 4 km from
the main Euphrates valley, on a side valley (b).
The site is an artificial mound (i.e. Tell) 8 m in
height, roughly circular (360 3 300 m) in shape,
delimited to the south and east by two rivers
(wadis) tributaries of the Euphrates (c). Latitude
and longitude above sea level of the
archaeological site are 35°559N, 38°309E, 300 m.
Average (1978–94) annual precipitation of the
closest meteorological stations around Halula
are: Membij (36°019N, 38°059E) 282 mm, El
Khafseh (36°129N, 38°049E) 211 mm and Mazra
et Maskaneh (36°329N, 37°579E) 206 mm.
Accumulated precipitation during April, the
first half of May, corresponding, in the case of
winter barley, with the period from headinganthesis to maturity (Araus et al. 1997a), was
33, 28 and 27 mm, respectively. Precipitation
during the second half of April plus May,
corresponding, in the case of durum wheat,
with the period between heading and maturity
was 23, 18 and 18 mm, respectively.
© 1999 Blackwell Science Ltd., Global Change Biology, 5, 201–212
203
204
J . L . A R A U S et al.
Fig. 2 Scanning electron micrographs of
charred seeds of durum wheat (a), lentil
(b) and flax (c) found in the site of Tell
Halula and used for stable carbon isotope
analysis.
radiocarbon ages. Radiocarbon determinations were
performed at Beta Analytic Inc. (Miami, FL, USA).
Dating ranged from c. 8700 6 60 BP to 7690 6 130 BP
uncalibrated. Calibrated ages were determined according to Stuiver & Reimer (1986) by using the computer
program CALIBTH3. After calibration the range of
dates for the material studied was 9550–8465 BP. In
addition samples from the present day (1997) were
taken from hulled barley cultivated in the same Tell
and its surroundings.
© 1999 Blackwell Science Ltd., Global Change Biology, 5, 201–212
W A T E R AVA I L A B I L I T Y I N E A R L Y A G R I C U L T U R E A N D ∆
Carbon-isotope analysis
Prior to stable carbon isotope analysis, seed samples were
cleaned as reported elsewhere (Araus & Buxó 1993).
The isotopic 13C/12C ratios were determined by mass
spectrometric analysis at Isotope Services, Inc., Los
Alamos, New Mexico, USA and the ‘Serveis Cientific
Tècnics de l’Universitat de Barcelona’, Barcelona, Spain.
Results are expressed as δ13C values, where:
δ13C(∆) 5 [(R sample/R standard) – 1] 3 1000,
(1)
13C/12C
ratio. A secondary standard calibR being the
rated against Peedee belemnite (PDB) carbonate was used
for comparison. Sample sizes of 5–10 mg were used. The
precision of analysis was less than 0.10 ‰. The percentage
of carbon in the set of samples was also determined
using a C/N analyser with atropine as the standard. The
potential effect of carbonization on δ13C of archaeological
grains was ignored based on findings reported elsewhere
(Marino & DeNiro 1987; Araus et al. 1997a,b). Moreover,
the total carbon content of fossil seeds was closely similar
to those of intact present-day seeds, which suggests a
slight carbonization process (Table 1). The stable nitrogen
composition (δ15N) of present-day barley seeds collected
at the archaeological site was also analysed by mass
spectrometric analysis. The ratio 15N/14N in the samples
was measured in relation to that of a standard of atmospheric N2, according to the same expression than (1)
(Amaro et al. 1995).
Discrimination against 13C relative to air (∆) was calculated from δa and δp, where a and p refer to air and
plant, respectively; as follows (Farquhar et al. 1989):
∆5
δ a – δp
1 1 δp
.
(2)
On the PDB scale, δa currently has a value of approximately – 8.00 ‰. For calculation of ∆ values of grain
samples from the archaeological site, δa values were
inferred from the work of Marino et al. (1992) as reported
elsewhere (Araus & Buxó 1993). Thus the δa values used
for the samples of the six different stratigraphic levels
were as follows: first level (c. 8700 BP uncalibrated)
– 6.609 ‰, second (c. 8350 BP) – 6.583 ‰, third
(c. 8300 BP) – 6.580 ‰, fourth (c. 8100 BP) – 6.568 ‰,
fifth (c. 7880 BP) – 6.552 ‰, and sixth (c. 7690 BP) – 6.539 ‰.
Water inputs during grain filling of archaeological
kernels
Precipitation accumulated during grain filling for the
archaeological kernels of durum wheat was estimated
from comparisons with present-day data. First we established an empirical relationship, for the durum wheat
currently cultivated in the Mediterranean area, between
© 1999 Blackwell Science Ltd., Global Change Biology, 5, 201–212
205
carbon discrimination of mature kernels on the one hand
and total water inputs accumulated from heading to crop
maturity on the other. The ∆ of wheat kernels from Tell
Halula was then used to calculate precipitation at the time
when these kernels were produced using the relationship
derived from contemporary data.
For a set of 11 environments (locations and/or years
of culture), mostly in the Mediterranean areas of Spain
and Syria, the correlation between ∆ of mature kernels
of durum wheat and the precipitation (plus irrigation
where applied) from heading to maturity was studied.
The timing of wheat heading and the further duration of
grain filling under Mediterranean conditions was based
on the records from these trials. Thus, total precipitation
during grain filling was calculated as the total rainfall
(plus irrigation) during April plus the first half of May
(autumn sowing) or during the second half of April plus
May (winter sowing). Current precipitation at Tell Halula
was estimated from historical (means from 1978 to 1994)
records of rainfall from the three meteorological stations
closest to this site (see Table 1). Given that old wheat
cultivars may have had a longer cycle and, thus, later
flowering, total precipitation during grain filling was
inferred as the overall rainfall during the second half of
April plus May.
Results and discussion
∆ of fossil seeds vs. those of current-day seeds
The carbon isotope composition (δ13C) of the fossil seeds
collected in the six stratigraphic levels studied at Tell
Halula, along with their total carbon content values are
detailed in Table 1. After calculation of carbon isotope
discrimination (∆), and except for two samples (one of
wheat and the other of lentil), all the seeds studied
showed ∆ values greater than 16 ‰, reaching 20 ‰ for
some samples of flax (Fig. 3a). Mean ∆ values of the seeds
found in the different stratigraphic levels corresponding
to either Middle Pre-Pottery Neolithic B (PPNB), Late
PPNB and Late Neolithic were plotted for each plant
species (Fig. 3b). Flax seeds showed higher values of ∆
than wheat kernels and lentil seeds during the Middle
and Late PPNB. Lentil seeds also tended to show higher
∆ values than wheat during the Late Neolithic, although
differences were not significant. This could reflect the
growth habit (Araus et al. 1997c), lentils being less determinate plants than wheat.
Values of ∆ of fossil seeds are very high for rainfed
crops growing under Mediterranean conditions. Thus,
for example, ∆ of wheat kernels were much higher than
those reported in present-day (1996) durum wheat crops
cultivated under rainfed conditions in north-west Syria
(Araus et al. 1997b) in environments with somewhat
206
J . L . A R A U S et al.
Table 1 Carbon isotope composition (δ13C, ‰) and carbon content (C, %) of fossil seeds of durum wheat, lentil and flax found in
Middle Pre-Pottery Neolithic B (M-PPNB), Late Pre-Neolithic B (L-PPNB) and Late Neolithic (L-N) levels at Tell Halula. All the dates
are in uncalibrated radiocarbon years BP. Means with different letters are significantly different (Pø0.05) by Duncan’s comparison test
Archaeological
levels
M-PPNB
Radiocarbon
ages
8800–8600
Mean 6 SE
L-PPNB
8500–8200
Mean 6 SE
L-N (Pre-Halaf)
Mean 6 SE
8200–7600
Durum wheat
Lentil
Flax
δ13C
C
δ13C
C
δ13C
C
–23.17
–25.34
–23.26
–23.68
–23.64
–23.43
–22.28
–24.14
–23.87
–23.54
–22.35
–22.37
41.48
46.19
37.27
46.04
46.50
47.91
41.66
43.86
43.28
47.01
45.12
40.39
–23.27
–22.45
–23.70
–24.24
27.34
19.62
39.40
40.59
–26.10
–25.34
41.39
51.99
–23.42 6 0.24bcd 43.89 6 0.88bc
–22.42 6 0.33bcd 31.74 6 4.35a
–25.72 6 0.27ab
46.69 6 3.75bc
–23.07
–24.59
–23.41
–24.25
–23.08
–22.45
–24.70
–22.41
–23.85
–24.17
–23.04
–23.12
–22.90
–21.62
–25.09
–24.46
–25.75
–23.97
46.72
47.22
53.86
49.06
44.40
41.83
46.15
47.08
46.10
48.36
46.86
45.20
34.74
42.81
45.85
49.10
30.37
41.58
–23.50 6 0.33bcd 46.23 6 0.75bc
–23.40 6 0.39bcd 41.38 6 2.31bc
–24.73 6 0.43abc 49.27 6 1.88bc
–22.00
–23.30
–23.56
45.17
46.44
44.98
–22.79
–22.89
–24.39
–22.57
–24.23
–22.95 6 0.39cd
45.53 6 0.37bc
–23.36 6 0.42bcd 40.79 6 0.97b
higher rainfall (Breda and Tel Hadya with about 340 and
390 mm per year, respectively) than Tell Halula (about
250 mm). Thus, ∆ values (mean 6 SD) for Breda and Tel
Hadya were 14.0 6 0.4 ‰ and 15.3 6 0.4 ‰, respectively,
which is clearly below those measured in the fossil
kernels (around 17 ‰) during the three periods studied
(Fig. 3a). Indeed fossil kernels showed ∆ values even
slightly higher than those (16.7 6 0.5 ‰) of durum wheat
cultivated with supplementary irrigation at Tel Hadya
(Araus et al. 1997b) and not much different from those
typical (over 17.5 ‰) of durum wheat grown in absence
of water stress (e.g. full irrigation, Araus et al. 1997c).
Samples from present-day (1997) hulled barley kernels
cultivated at seven points of the archaeological site were
also analysed. These barley crops grow without significant (if any) amounts of chemical nitrogen fertilization, as
inferred from the low total nitrogen content (mean 6 SE 5
1.52 6 0.11%) and the high 15N isotopic composition
(δ15N 5 6.63 6 1.26 ‰) of kernels (Amaro et al. 1995), a
42.31
41.60
37.38
44.40
55.38
–23.40 6 0.59bcd 49.89 6 3.88c
situation resembling that expected in ancient agriculture.
Mean 6 SE of ∆ was 16.02 6 0.19 ‰. This value is again
clearly below ∆ values for all the archaeological seeds.
Moreover, under present-day conditions, ∆ of durum
wheat would be even lower. Considering that barley
attains maturity at least 2–3 weeks earlier than durum
wheat, under Mediterranean conditions the grain filling
period for barley usually takes place under wetter conditions than those expected for durum wheat. Indeed this
difference in phenology between both crops is one of the
main reasons why barley is the only cereal cultivated
under rainfed conditions in areas with rainfall regimes
comparable to that which currently predominates in
Tel Halula.
Water status during wheat cultivation
The relationship between ∆ of wheat kernels and water
status from heading to maturity under Mediterranean
© 1999 Blackwell Science Ltd., Global Change Biology, 5, 201–212
W A T E R AVA I L A B I L I T Y I N E A R L Y A G R I C U L T U R E A N D ∆
conditions was studied in more detail. Carbon isotope
discrimination of kernels from recent years was positively
correlated with accumulated precipitation (plus irrigation
where applied). Differences in water inputs (on a logarithmic scale) between environments explained 82% (∆ 5
6.95 1 4.85 log [water received from heading to maturity];
r2 5 0.82) of the variability observed in the ∆ of mature
kernels (Fig. 4). The fitting line showed the same slope
(P ø 0.05) as that previously reported for barley (see
dotted line in Fig. 4) cultivated under mediterranean
conditions (Araus et al. 1997a). However, fitting line for
wheat was shifted somewhat to the right (P 5 0.077),
207
which would agree with a higher vapor pressure deficit
during the latter part of wheat growth than that of barley
and might be explained by the later occurrence of this
period in the former crop. Thus, for barley cultivated
under Mediterranean conditions differences between
environments in terms of water status (also on a logarithmic scale) from heading to maturity explained 73% of
the variability in ∆ of mature kernels (Araus et al. 1997a).
The results of Stewart et al. (1995) which show a strong
(linear) correlation (r2 5 0.78) between annual rainfall
and δ13C across a set of 12 plant communities also support
the usefulness of δ13C (or ∆) as an indicator of moisture
availability. In both cases, the further addition (by multiple regression) of the effect of evapotranspiration to
that of water inputs did not explain a higher percentage
of variability in ∆ of kernels. ∆ in photosynthate may
also respond to mean relative humidity in the atmosphere
by itself as derived from the model of Ball et al. (1987).
Thus, for example, a shift in relative humidity in the
canopy, ignoring offsets between leaf temperature and
air temperature, from 50% to 60% would account for a
1.2 ‰ increase in ∆. However, the variations in ∆ in
response to shifts in relative humidity seems to be
substantially lower than those predicted by the model
at low relative humidities. Actually whereas a relative
humidity of 30% would lead to a ∆ of about 15 ‰,
relative humidities of 20% and 10% would produce ∆
values of 9 ‰ and – 9 ‰, respectively, which are far
outside the range of experimental data.
From the equation fitted above (Fig. 4), and by using
the corresponding ∆ values of fossil kernels, the amount
of water received (from heading to maturity) by the
Neolithic wheat crops of Tel Halula could be calculated
(Fig. 5). Thus, for the durum wheat kernels found in
the Medium and Late PPNB sequences the total water
received by the crop from heading to maturity surpassed
Fig. 3 Upper (a). Carbon isotope discrimination of durum wheat,
lentil and flax seeds found in 6 different stratigraphic levels of
Tell Halula. All dates are in uncalibrated radiocarbon years BP.
Samples ranged from Middle PPNB (c. 8700 6 60 BP uncalibrated
and 9550 BP calibrated) to late Neolithic (c. 7690 6 130 BP
uncalibrated and 8465 BP calibrated). ∆ values from present-day
(1996) mature kernels of durum wheat cultivated under rainfed
conditions in north-west Syria in environments with similar
(Breda) or somewhat higher (Tel Hadya) precipitation than Tell
Halula are presented for comparison. For these two
environments values presented are means 6 SD of 144 genotypes
and two plots each (Araus et al. 1997b). Lower (b). Mean 6 SE
of ∆ values of durum wheat, lentil and flax seeds found in
stratigraphic levels of Tell Halula corresponding to Middle PPNB
(M-PPNB), Late PPNB (L-PPNB) and Late Neolithic (L-N).
Means with different letters are significantly different (P ø 0.05)
by Duncan’s comparison test.
© 1999 Blackwell Science Ltd., Global Change Biology, 5, 201–212
208
J . L . A R A U S et al.
Fig. 4 Relationship between total precipitation (plus irrigation
if the case) from heading to maturity and carbon isotope
discrimination of mature durum wheat kernels (continuous
fitting line) for a set of 11 trials developed in Spain, Syria and
Mexico. For each Spanish and Mexican trial, the ∆ value used
in the correlation was the mean of 6–10 varieties, whereas for
Syrian trials ∆ was the mean of 125 genotypes. Samples are
drawn from breeding trials, including old and new varieties.
Discrimination values from Syrian trials (Araus et al. 1997b) and
from some of the Spanish trials (Araus et al. 1993) have been
published previously. Broken line represents the relationship
between water inputs and ∆ for barley currently cultivated
under mediterranean conditions as reported elsewhere (Araus
et al. 1997a). Fitting equation for data of barley and wheat
combined was ∆ 5 9.58 1 3.65 (log. mm water), r2 5 0.72,
C.V. 5 4.75)
130 mm and fell to below 110 mm during late Neolithic
(Fig. 5). These amounts of water are much greater than
the present-day precipitation for the Middle Euphrates
region during this period (of almost 7 weeks) of spring.
Thus, the average (1978–94) precipitation in the three
meteorological stations closest to Halula (Fig. 1) accumulated during the second half of April plus May was
around 20 mm (Fig. 5). Whereas this period of time would
probably fit better with the phenology of old (or ancient)
wheat genotypes which may have been later heading
and flowering (see references in Slafer et al. 1993; Araus
et al. 1997a), were we to consider the period from April
to the first half of May the accumulated precipitation
would only increase by about 30 mm. In any case, these
values differ greatly from those calculated in fossil wheat
kernels. Additionally, the accumulated precipitation at
Tell Halula during April plus the first half of May of
1997 was also estimated, from the ∆ of barley kernels
collected around the archaeological site, using the
reported relationship for this crop between ∆ of kernels
and water status (Araus et al. 1997a). Although the
estimated precipitation was 56 mm (which agrees with
the wet spring season of this particular year), this value
was still less than half of the estimated water inputs for
the fossil wheat kernels (Fig. 5).
Fig. 5 Comparison
between
present-day
precipitation
accumulated from heading to maturity of durum wheat and
barley and water inputs calculated for durum wheat from the
Neolithic at Tell Halula. Present-day data correspond to mean
values (1978–94) of accumulated precipitation during April plus
the first half of May (barley: open bars) and the second half of
April plus May (durum wheat: filled bars) recorded in the three
meteorological stations closest to Tell Halula (see legend of
Fig. 1). Mean water inputs 6 SE from heading to maturity of
durum wheat (filled bars) during the three Neolithic periods
were calculated using the ∆ values of fossil kernels for each
period and the equation in Fig. 4. In addition, precipitation from
heading to maturity of barley (April and first half of May)
cultivated at Tell Halula in 1996 was also estimated using the ∆
values of kernels and the relationship between total water inputs
during grain filling and ∆ of mature barley reported elsewhere
(Araus et al. 1997a).
With regard to the risk inherent in using present
vegetation–climate relationships to reconstruct past water
status from the archaeological record, the direct effect
of changing atmospheric CO2 level on the relationship
between water inputs and grain ∆ should be considered.
In long-term experiments, it has been reported that the
pi/pa ratio (calculated from leaf δ13C values) remained
constant in a cereal plant such as oats grown at mean
CO2 partial pressure from 160 to 330 µbar bar–1, and for
wheat it increased only slightly (about 4%) from 225 to
350 µbar bar–1 (Masle et al. 1990; Polley et al. 1993). A
recent study using δ13C of woody plant remains (Beerling
1996) reports that these plants probably maintained a
nearly constant pi/pa ratio in response to the increase in
atmospheric CO2 concentrations over the Pleistocene.
In fact, the coordination of stomatal and mesophyll
functions minimizes variations in pi/pa in C3 species
(Wong et al. 1979) grown over a range of CO2 partial
© 1999 Blackwell Science Ltd., Global Change Biology, 5, 201–212
W A T E R AVA I L A B I L I T Y I N E A R L Y A G R I C U L T U R E A N D ∆
pressures characteristic of the Last Glacial Maximum-topresent atmospheric concentrations (Polley et al. 1993).
In fact Ehleringer (1995) postulates that pi can be considered as a ‘set point’ for photosynthetic activity, providing
integrated information about photosynthetic metabolism.
Thus pi as a ‘set point’ would be more stable than the
absolute flux rates of CO2 uptake. That is, whereas
absolute flux rates will vary greatly in response to
resource levels over the short-term or due to stress levels
over the long-term, changes in the set point may be
substantially less. Therefore, here we considered that
changing pa values from about 270 µbar bar–1, prior to
industrialization, to a present-day value of 355 µbar
bar–1 would not affect the pi/pa ratio and therefore based
on the model of Farquhar et al. (1989), the ∆ would not
change. Furthermore, even if pi/pa values from durum
wheat plants of Neolithic were slightly lower than those of
the present day, the inferred (i.e. calculated) precipitation
from the archaeological sites may be slightly underestimated. On the other hand, the lower pa during Neolithic
would lead to a higher stomatal conductance and therefore to higher transpiration rates. If it is accepted that ∆
remains relatively steady within the range of changes in
pa monitored during the Holocene, it can be concluded
that a given ∆ value could not have been attained in the
past without greater amounts of water than those needed
today. Therefore, in the worst case our approach would
provide a conservative (low) estimate of the differences
in water availability from past to present time.
Although other sources of uncertainty associated with
carbonization of grains (Araus & Buxó 1993), differences
in the rate of decline of soil water content, or changes in
conditions of cultivation and in genotype are difficult to
evaluate, the data available do not seem to invalidate
this approach and it might even suggest (for some of
these parameters) that a conservative estimate of water
status in the past is obtained (see discussion in Araus
et al. 1997a,b). There is for example the possibility of
systematic differences between ancient (i.e. cultivated
several millennia ago) and new wheats in ∆. The available
information suggests that modern varieties show consistently higher ∆ values than the old (i.e. reported to be
cultivated during the last century) varieties and landraces
not only in wheat (see references in Blum 1996) but
also in barley (Muñoz et al. 1998). A higher stomatal
conductance and earlier flowering and maturation in
new genotypes could be responsible (see Richards 1996).
Whatever the cause a systematically lower ∆ in older
wheats would again lead to a conservative estimate of
water status in the past.
Further insights into the palaeoenvironmental context
of early agriculture
The above results clearly indicate that during the period
studied wheat was cultivated at Tell Halula under a
© 1999 Blackwell Science Ltd., Global Change Biology, 5, 201–212
209
much better water status than could be expected from
present-day (rainfed) conditions. Whereas the presence
of flax also supports this conclusion, its very high ∆
values should be interpreted with caution due to the fact
that flax is a oil-rich seed and there is a discrimination
against 13C during the process of oil biosynthesis. Cultivation under moister conditions could have been possible
as a result of more humid environmental conditions
prevailing at this time or by planting in alluvial areas
(Bar-Yosef & Kislev 1989). Another possibility lies in
the existence of irrigation practices. Indeed one indirect
method to assess the presence of ancient irrigation takes
into consideration the development of weeds; for
example, from the size of charred flax seeds which
occurred in an archaeological assemblage of plant remains
(Helbaek 1960). However, even when flax seeds were
very abundant in all the stratigraphic levels studied at
Tell Halula their length did not reach 3.0 mm, which has
been proposed as the minimum size for domesticated
plants. As yet, there is no archaeological evidence for
irrigation in the early (i.e. Neolithic) agricultural sites of
the Near East (Bar-Yosef & Kislev 1989; Hillman & Davies
1990), including Tell Halula (Molist et al. 1995). For durum
wheat, although ∆ of fossil kernels were higher than
those of present-day kernels cultivated under rainfed
conditions, due to the existence of a better water status
in the past, they were still lower than the typical values
of full irrigation crops under Mediterranean conditions
(Araus et al. 1997c). Because ∆ appears to show a logarithmic dependence on water accumulated from heading to
maturity (Fig. 4), ∆ values fall slightly below those
reported for full irrigated wheat crops (over 17.5 ‰) and
would seem to be associated with considerably lower
amounts of water being available during grain filling.
Thus, an ∆ value 0.5 ‰ lower than 17.5 ‰ would
correspond to the availability of an amount of water
during grain filling which was about 30% lower than
that for irrigated crops (Araus et al. 1997a). Of course,
any condition in between rainfed and full irrigation (i.e.
supplementary irrigation) would produce kernels with ∆
values below those of full irrigation.
The existence of a wetter climate in the past is a more
plausible possibility. Archaeobotanical evidence supports
the possibility that environmental conditions during early
agriculture were more favourable (i.e. cooler and moister)
in this region than nowadays. The presence of charcoal
from ash, vine, maple, plane, alder and elm from the
gallery forest, and wild rye, wild einkorn, deciduous oak,
wild almond, Pistacia, and Pyrus, from the hinterland,
suggests moister and cooler conditions in the Middle
Euphrates region during early agriculture (Harlan 1995;
Willcox 1996; see also Hillman et al. 1993). Particularly in
Tell Halula, although no evidence of rye appears, the
presence of Quercus, Amygdalus, Pistacia, Celtis and Olea
210
J . L . A R A U S et al.
europaea during the PPNB suggests that climate was much
more humid than during the present-day (Willcox &
Català 1996; Willcox 1996). In addition, not only a higher
overall precipitation (and perhaps a lower evapotranspiration), but also the seasonal distribution of precipitations,
would be involved. Thus at the site of Mureybet (on the
Middle Euphrates), it has been reported that about 8000 BP
Poaceae pollen was, in relative terms, much more abundant than today (El-Moslimany 1994). This suggests that
summer precipitation was much higher than today. A
shift throughout the region to dominant winter rainfall
(typical of Mediterranean climates) would have occurred
after 6000 BP (El-Moslimany 1994). Because durum wheat
and flax seed formation takes place in late spring (and
also early summer for flax), any increase in precipitation
during this period, even when total accumulated rainfall
during cultivation does not vary, would eventually lead
to higher ∆ in seeds.
However, palaeoenvironmental reconstruction through
the archaeobotanical study of past vegetation has serious
limitations. Present-day natural vegetation corresponding
to a degraded steppe could be the consequence of man’s
effect on the landscape. Expansion of cultivation as well
as the (early) great development of extensive goat and
sheep pastoralism (Thirgood 1981), rather than climatic
change, could be responsible (at least in part) for this
increase in landscape degradation (Willcox 1996) and
the contemporary steppe/weed vegetation. Thus, annual
weed plants, usually associated with open landscape and
the cultivation of cereals, among other crops, were already
present in the early crop assemblage of Tell Halula.
Among these annual plants it is worth mentioning the
genera Agrostemma, Arnebia, Astragalus, Centaurea,
Fumaria, Glaucium, Lithospermum, Rumex, Sherardia and
Teucrium (Table 2). The weeds more specifically associated
with legume cultivation are Astralagus, Atriplex, Chenopodium, Galium and Trifolium; whereas Lolium would more
likely be associated with flax cultures.
Nevertheless the pattern of changes with time in ∆
would agree with a gradual change in climate to drier
conditions. Thus, as a general trend mean ∆ values
tended to decrease throughout the millennium comprised
between M-PPNB to Late Neolithic. This was particularly
evident for flax (Fig. 3b), which is reported to be an
indicator of high water availability (Hole 1998). Indeed
the first evidence of domesticated plants (cereals) at Tell
Halula appear a full thousand years after the Climatic
Optimum was already established (Becker et al. 1991).
Therefore, the progressive attenuation of the Climatic
Optimum until around 6000 years ago, when climatic
conditions were not very different from those prevailing
at present were established throughout the Near East
(Roberts & Wright 1993), would agree with this tendency
to lower ∆ values. However, the constancy in high ∆
Table 2 Identified carbonized weed plant remains
Taxa
Middle
PPNB
Late
PPNB
Late
Neolithic
Agrostemma githago
Androsace
Arnebia
Astralagus
Atriplex
Avena
Bromus
Capparis
Carex
Centaurea
Chenopodium
Fumaria
Galium
Glaucium
Heliotropium
Isatis
Lithospermum
Lolium temulentun
Malva
Polygonum
Reseda
Rumex
Setaria
Sherardia
Teucrium
Trifolium
—
—
P
P
—
—
P
P
—
P
—
P
P
P
—
P
P
P
—
—
—
P
—
—
P
—
P
P
P
P
—
—
P
P
P
—
P
—
P
—
P
—
—
P
P
P
P
P
P
—
P
P
—
—
P
—
P
P
—
—
—
P
P
—
P
P
—
—
P
P
—
P
—
—
—
P
—
—
P indicates a record
values for almost all the samples analysed in the three
crops (Fig. 3) and the strong (more than five times)
difference in water inputs estimated from past to present
conditions at Tell Halula (Fig. 5) seems difficult to explain
just by a wetter climate prevailing in the past. In this
context a wetter climate combined with planting in
naturally wet soils may have been typical. In fact one
way of stabilizing yields that were fluctuating because
of water stress is small-scale cultivation in areas fed
by permanent springs and duly cleared of competing
vegetation (Hillman 1996). The exploitation of naturally
wet soils is widely found in early agricultural sites of the
Near East (Bar-Yosef & Kislev 1989). It has been argued
that cultivation, whenever possible, was based on the
sowing of alluvial fans and terraces as well as the edges
of freshwater swamps where the water table was always
high and the soil was fertilized by silt deposited by
periodic floods. As Hillman (1996) point out, once native
vegetation was eliminated the moisture-enhanced soils
on small terraces and other breaks of slope around the
lower reaches of wadi systems which characterized most
of the favoured (i.e. oasis) locations (see Fig. 1c for Tell
Halula) would have made possible yields far greater than
in the drier locations where the cereals grew naturally.
© 1999 Blackwell Science Ltd., Global Change Biology, 5, 201–212
W A T E R AVA I L A B I L I T Y I N E A R L Y A G R I C U L T U R E A N D ∆
Conclusions
To summarize, our results provide direct evidence that
during early agriculture wheat crops were cultivated
at Tell Halula under much wetter conditions than are
suggested by present-day conditions. The presence of
flax and its very high ∆ values also support this conclusion. Higher water availability may have been attained
exclusively from the moister (and cooler) conditions
prevailing at this time. However, the large differences
between present-day rainfall and the estimated water
input in the past, also suggest the possibility that cultural
practices such as planting in naturally wet soils were
followed.
Acknowledgements
We wish to thank Dr C. Royo and J. Zarco from UdL-IRTA,
Lleida (Spain), and E. Sanchez-Monge from SENASA, Pamplona
(Spain), for supplying accumulated water inputs, together with
kernel samples and ∆ values from several durum wheat trials.
We are also very grateful to G. Willcox, from the CNRS of Jalès
(France) for supervising palaeobotanical determinations and to
Annette Oberle, from ICARDA, Aleppo (Syria) for providing
the climatic data close to the Halula site. The constructive
comments raised on the manuscript by Drs T. Dawson, V.P.
Gutschick, and Roger B. Austin as well as those of the anonymous
referee also are appreciated. This work was supported in part
by the grants CICYT AGF95-1008-C05-03 and A6F96-1137-C0203 and a fellowship DGICYT PR95-006 (Spain)
References
Amaro T, Bergareche C, Araus JL (1995) Changes in Stable C
and N isotope composition in barley as affected by N
nutrition and sowing date. Interdrought. In: Proceedings of
the International Congress on Integrated Studies on Drought
Tolerance of Higher Plants, pp. III- 1. Montpellier.
Araus JL, Amaro T, Zuhair Y, Nachit MM (1997b) Effect of leaf
structure and water status on carbon isotope discrimination
in field grown durum wheat. Plant, Cell and Environment, 20,
1484–1494.
Araus JL, Brown HR, Febrero A, Bort J, Serret MD (1993)
Ear photosynthesis, carbon isotope discrimination and the
contribution of respiratory CO2 to differences in grain mass
in durum wheat. Plant, Cell and Environment, 16, 383–392.
Araus JL, Buxó R (1993) Changes in carbon isotope
discrimination in grain cereals from the north-western
mediterranean basin during the past seven millennia.
Australian Journal of Plant Physiology, 20, 117–128.
Araus JL, Buxó R, Febrero A et al. (1997c) Identification of
Ancient Irrigation Practices based on the Carbon Isotope
Discrimination of Plant Seeds: a Case Study from the
Southeast Iberian Peninsula. Journal of Archaeological Science,
24, 729–740.
Araus JL, Febrero A, Buxó R et al. (1997a) Changes in carbon
isotope discrimination in grain cereals from different regions
of the western Mediterranean Basin during the past seven
© 1999 Blackwell Science Ltd., Global Change Biology, 5, 201–212
211
millennia. Palaeoenvironmental evidence of a differential
change in aridity during the late Holocene. Global Change
Biology, 3, 107–118.
Ball JT, Woodrow IE, Berry JA (1987) A model predicting
stomatal conductance and its contribution to the control of
photosynthesis under different environmental conditions. In:
Progress in Photosynthesis Research (ed. Biggins J), pp. 221–
224. M. Nijhoff Publishers, Dordrecht.
Baruch U, Bottema S (1991) Palynological evidence for climatic
changes in the Levant ca. 17,000–9,000 B.P. In: The Natufian
culture in the Levant. International Monographs in Prehistory
(eds Bar–Yosef O, Valla F), pp. 11–20. Ann Arbor, Michigan.
Bar-Yosef O, Kislev M (1989) Early farming communities in the
Jordan Valley. In: Foraging and Farming. The evolution of plant
exploitation (eds Harris DR, Hillman GC), pp. 633–642. Unwin
Hyman, London.
Becker BB, Kromer B, Trimborn P (1991) A stable isotope treering time scale on the Late Glacial/Holocene boundary.
Nature, 353, 647–649.
Beerling DJ (1996) Ecophysiological responses of woody plants
to past CO2 concentrations. Tree Physiology, 16, 389–396.
Blum A (1996) Yield potential and drought resistance: are they
mutually exclusive? In: Increasing Yield Potential in Wheat:
Breaking the Barriers (eds Reynolds MP, Rajaram S, McNab A),
pp. 76–89. CIMMYT, México.
Condon AG, Richards RA, Farquhar GD (1987) Carbon isotope
discrimination is positively correlated with grain yield and
dry matter production in field-grown wheat. Crop Science,
27, 996–1001.
Condon AG, Richards RA, Farquhar GD (1992) The effect of
variation in soil water availability, vapor pressure deficit and
nitrogen nutrition on carbon isotope discrimination in wheat.
Australian Journal of Agricultural Research, 43, 935–947.
Craufurd PQ, Austin RB, Acevedo E, Hall MA (1991) Carbon
isotope discrimination and grain yield in barley. Field Crop
Research, 27, 301–313.
Ehleringer JR (1995) Variation in gas exchange characteristics
among desert plants. In: The Ecophysiology of Photosynthesis.
Ecological Studies, Vol. 100 (eds Schulze ED, Caldwell MM),
pp. 361–392. Springer, Berlin.
El-Moslimany AP (1994) Evidence of early Holocene summer
precipitation in the continental Middle East. In: Late
Quaternary Chronology and Paleoclimates of the Eastern
Mediterranean (eds Bar-Yosef O, Kra RS), pp. 121–130.
Radiocarbon, Department of Geosciences, The University of
Arizona, Tucson.
Farquhar GD, Ehleringer JR, Hubick KT (1989) Carbon isotope
discrimination and photosynthesis. Annual Review of Plant
Physiology and Plant Molecular Biology, 40, 503–537.
Farquhar GD, Richards RA (1984) Isotopic composition of plant
carbon correlates with water-use efficiency of wheat
genotypes. Australian Journal of Plant Physiology, 11, 539–552.
Harlan JR (1995) The Living Fields: Our Agricultural Heritage.
Cambridge University Press, Cambridge.
Helbaek H (1960) Cereals and weed grasses in Phase A. In:
Excavations in the Plain of Antioch I (eds Braidwood RJ,
Braidwood LS), pp. 540–543. University of Chicago Press,
Chicago.
212
J . L . A R A U S et al.
Hillman G (1996) Late Pleistocene changes in wild plant-foods
available to hunter-gatherers of the northern Fertile Crecent:
possible preludes to cereal cultivation. In: The Origins and
Spread of Agriculture and Pastoralism in Eurasia (ed. Harris
DR), pp. 159–203. University College London Press, London.
Hillman G, Davies S (1990) Measured domestication rates in
wild wheats and barley under primitive cultivation, and
their archaeological implications. Journal of World Prehistory,
4, 157–219.
Hillman G, Wales S, Mc Laren F, Evans J, Butler A (1993)
Identifying problematic remains of ancient plant foods: a
comparison of the role of chemical, histological and
morphological criteria. World Archaeology, 25, 94–121.
Hole F (1998) The spread of agriculture to the eastern arc of the
fertile crescent: food for herders. In: The Origins of Agriculture
and the Domestication of Crop Plants in the Near East (eds
Valkoun J, Damania AB). ICARDA, Aleppo.
Ladizinsky G (1987) Pulse domestication before cultivation.
Economic Botany, 41, 60–65.
Ladizinsky G (1989) Pulse domestication: Fact or Fiction?
Economic Botany, 43, 131–132.
Marino BD, DeNiro MJ (1987) Isotopic analysis or
archaeobotanicals to reconstruct past climates: effects of
activities associated with food preparation on carbon,
hydrogen and oxygen isotope ratios of plant cellulose. Journal
of Archaeological Science, 14, 537–548.
Marino BD, McElroy MB, Salawitch RJ, Spaulding GD (1992)
Glacial-to-interglacial variations in the carbon isotopic
composition of atmospheric CO2. Nature, 357, 461–466.
Masle J, Farquhar GD, Gifford RM (1990) Growth and carbon
economy of wheat seedlings as affected by soil resistance to
penetration and ambient partial pressure of CO2. Australian
Journal of Plant Physiology, 17, 465–487.
Molist M, Anfruns J, Català M et al. (1995) Tell Halula (Siria),
un poblat dels primers agricultors i ramaders del VII milleni
a la vall de l’Eufrates. Tribuna D’arqueologia, 1992–93, 49–61.
Moore AMT, Hillman GC (1992) The Pleistocene to Holocene
transition and human economy in south-west Asia: the
impact of the Younger Dryas. American Antiquity, 57, 482–494.
Muñoz P, Voltas J, Araus JL, Igartua E, Romagosa I (1998)
Changes in adaptation of two- and six- rowed barley releases
over time in Northeastern Spain. Plant Breeding, (in press).
Polley HW, Johnson HB, Marino BD, Mayeux HS (1993) Increase
in C3 plant water-use efficiency and biomass over Glacial to
present CO2 concentrations. Nature, 361, 61–64.
Richards RA (1996) Defining selection criteria to improve yield
under drought. Plant Growth Regulation, 20, 157–166.
Roberts N, Wright HE Jr (1993) Vegetational, lake-level, and
climatic history of the Near East and Southwest Asia. In:
Global Climates Since the Last Glacial Maximum (eds Wright Jr
HE, Kutzbach JE, Webbet TI), pp. 194–220. University of
Minnesota Press, Minneapolis, MN.
Romagosa I, Araus JL (1991) Genotype–environment interaction
for grain yield and 13C discrimination in barley. Barley
Genetics, VI, 563–567.
Rossignol-Strick M (1993) Late Quaternary climate in the eastern
Mediterranean region. Paléorient, 19, 135–151.
Slafer GA, Satorre EH, Andrade FH (1993) Increases in grain yield
in bread wheat from breeding and associated physiological
changes. In: Genetic Improvements of Field Crops: Current Status
and Development (ed. Slafer G), pp. 1–68. Marcel Dekker,
New York.
Stewart GR, Turnbull MH, Schmidt S, Erskine PD (1995) 13C
natural abundance in plant communities along a rainfall
gradient: a biological integrator of water availability.
Australian Journal of Plant Physiology, 22, 51–55.
Stuiver M, Reimer PJ (1986) A computer program for radiocarbon
age calibration. Radiocarbon, 28, 1022–1030.
Thirgood JV (1981) Man and the Mediterranean Forest. A history of
resource depletion. Academic Press, London, 194pp.
Willcox G (1991) La culture inventée, la domestication
inconsciente: le début de l’agriculture au Proche Orient. In:
Rites et ryhmes agraires (ed. Cauvin MC), pp. 9–31. Travaux
Maison L’Oriente 20, Paris.
Willcox G (1992) Archaeobotanical significance of growing Near
Eastern progenitors of domestic plants at Jalès (France). In:
Préhistoire de l’agriculture: nouvelles approaches expérimentales
et ethnographiques (ed. Anderson P), Monographie du CRA
6, pp. 159–178. CNRS, Paris.
Willcox G (1996) Evidence for plant exploitation and vegetation
history from three Early Neolithic pre-pottery sites on the
Euphrates (Syria). Vegetation History and Archaeobotany, 5,
143–152.
Willcox G, Català M (1996) Análisis paleobotánico. In: Tell Halula
(Siria) un yacimiento Neolı́tico del valle medio del Eufrates
campañas de 1991 y 1992. Informes arqueológicos (ed. Molist M),
pp. 135–142. Instituto del Patrimonio Histórico Español,
Ministerio de Cultura, Madrid.
Wong SC, Cowan IR, Farquhar GD (1979) Stomatal conductance
correlates with photosynthetic capacity. Nature, 282, 424–426.
van Zeist W, Bkker-Heeres JAH (1982) Archaeological studies in
the Levant. I. Neolithic sites in the Damascus basin: Aswad,
Ghoraifé, Ramad. Palaeohistoria, 24, 165–256.
Zohary D (1989) Pulse domestication and cereal domestication:
How different are they? Economic Botany, 43, 31–34.
Zohary D (1996) The mode of domestication of the founder
crops of Southwest Asian agriculture. In: The Origins and
Spread of Agriculture and Pastoralism in Eurasia (ed. Harris
DR), pp. 142–158. University College London Press, London.
© 1999 Blackwell Science Ltd., Global Change Biology, 5, 201–212