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Woodland use in the Montafon during Bronze AgeAnton Stefan Schwarz1 & Klaus Oeggl1
Early Bronze Agecharcoal spectrum
Others11%
Deciduous13%Pioneers
2%
Coniferous74%
Literature:Krause R., 2006: Zur bronzezeitlichen Siedlungskammer im Montafon. Neue Ausgrabungen in Bartholomäberg. Bezirk Bludenz. Jahrbuch des Vorarlberger Landesmuseums 149, 47-60.Schmidl A., Kofler W., Oeggl-Wahlmüller N. & Oeggl K., 2005: Land use in the eastern Alps during the Bronze Age - An archaeobotanical case study of a hilltop settlement in the Montafon (Western Austria), Archaeometry (2005) 47, 2, 455-470.Schwarz A. S., Krause R., Oeggl K., (in press): Anthracological analysis from a mining site in the Eastern Alps to evaluate woodland uses during the Bronze Age. Proceedings of the 4th International Meeting of Anthracology, British Archaeological Reports International Series.1 Innsbruck University, Institute of Botany, Sternwartestrasse 15, A-6020 Innsbruck, Austria; e-mail: [email protected]; [email protected]
Middle Bronze Agecharcoal spectrum
Others3%
Deciduous2%
Coniferous65%
Pioneers30%
IntroductionIn the Montafon (Vorarlberg, Austria) archaeological excavations (Fig.1) unearthed a fortified hilltop settlement ‘Friaga’ (Fig.2). The site was inhabited during the Early (19th/18th cent. BC), the Middle Bronze Age (16th/15th cent. BC) and the Iron Age (6th/5th cent. BC). Carbonised plant remains indicate a well developed Bronze Age husbandry regime. Previous palynological results from a nearby mire disclose large scale regional settlement activities during the Bronze Age (Schmidl et al., 2005). In the vicinity of the settlement ‘Friaga’ an additional dwelling place ‘Bodaweg’(Fig.3) was occupied during the late Early (18th/17th cent. BC) and the younger Middle Bronze Age (14th/13th cent. BC). The cultural layers are concentrated in several pits (Fig.3) dispersed randomly over the excavation site. The analysis of the charcoal (Fig.4) enables an estimation of the use of wood in prehistory.
AcknowledgementsThis study was carried out within the special research programme HiMAT’The History of Mining Activities in the Tyrol and Adjacent Areas – Impact on Environment & Human Societies’ (www.uibk.ac.at/himat) funded by the Austrian National Science Fund FWF (grant nos: F3108, F3111), Land Vorarlberg, Stand Montafon and the communes Bartholomäberg and Silbertal.
Tab.1: Other carbonised macro plant remains found from 18 charcoal-rich samples at the excavation site ‘Bodaweg’.
Results and DiscussionCharcoal analysis suggest an undisturbed mountain mixed forest (Abieti-Piceetum) in the surroundings of the settlement during the Early Bronze Age. Spruce (Picea/Larix type) is dominant, whereas beech (Fagussylvatica), fir (Abies), maple (Acer) and lime (Tilia) are admixed. During Middle Bronze Age the occurrence of charcoal from pioneer species like birch (Betula), hazel (Corylus avellana), alder (Alnus) and rowan (Sorbus) reflects an extensive opening of the forest.All timber had mean diameters <10cm (Tab.2) and was in most cases 11 to 40 years old (Fig.5). These indicate burning of branches and twigs as well as young trees. The constant gathering of timber from Early Bronze Age onwards led to a retreat of the natural climax wood.Consequently, the Middle Bronze Age pits reveal high amounts of fast growing and light demanding pioneer species (Fig.6 and Fig.7). Deciduous wood derives mainly from hedges or coppices admixed with a few branches from adult trees, e.g. beech (Fagus sylvatica) or maple (Acer). Coniferous wood is still mainly composed by branches and twigs from adult trees resulting in ongoing forest opening e.g. for pasturing (Schwarz et al., in press). Palynological records (Fig.8) of the nearby mire ‘Tschuga’ reaffirm an immense Bronze Age clearing by a sudden decrease of spruce (Picea) and fir (Abies) associated with an increase of grasses (Gramineae) in the pollen diagram (Schmidl et al., 2005). The anthropogenic impact is well documented by the frequent presence of cultural and pastoral indicators together with the increase of micro charcoal particles, particularly during the Middle Bronze Age.
Fig.8: Simplified pollen percentage diagram of the mire at Tschuga. EBA = Early Bronze Age, MBA = Middle Bronze Age, LBA = Late Bronze Age, IA = Iron Age, RA = Roman Age, MA = Middle Ages, MT = Modern Times (Schmidl et al. 2005).
ConclusionThe charcoal analysis reflects the anthropogenic change of the local woodland over time. The Early Bronze Age mountain mixed forest (Fig.9) shifted into a more open spruce (Picea)-dominated mixed forest with high values of pioneers (Fig.10) in the Middle Bronze Age, indicating a consistent anthropogenic opening of the forest. In addition, palynological studies from a nearby mire reaffirm a high demand on farming land and timber during Bronze Age.
Fig.5: The calculated age classes a) of the deciduous and b) the coniferous wood suggest the burning of branches and twigs from adult trees and wood from a coppice or hedge. The age was calculated by dividing the radius of the piece by the mean ring width.
Tab.2: Results of the charcoal analysis presented in percentage values from the excavation site ‘Bodaweg’. The pits are ordered chronological. Species ordered following ecological dispersal. If possible, the radius of the charcoal pieces was measured and the mean diameter (mD) was calculated from coniferous as well from deciduous wood for each sample.
Fig.6: Pits ordered in case of a Principle Component Analysis of the percent values (√%) of charred species. Same types of pits cluster together. The difference between Early Bronze Age pits and Middle Bronze Age pits is obvious. Furthermore differ the two types of pits from the Middle Bronze Age in their charcoal composition.Yellow: Middle Bronze Age ‘type b’ pit; green: Middle Bronze Age ‘type a’ pit; blue: Early Bronze Age ‘type eba’ pit.
Fig.7: The Principle Component Analysis of the percent values (√%) of the usedspecies in detail. The direction and length of the arrows indicate the influence of the species for position of the sample in the diagram. Positive correlating arrows point to the same direction, while negative correlating species show opposite directions.Yellow: Middle Bronze Age ‘type b’ pit; green: Middle Bronze Age ‘type a’ pit; blue: Early Bronze Age ‘type eba’ pit.
Fig.10: Composition of the Middle Bronze Age wood (n=1000).
Fig.9: Composition of the Early Bronze Age wood (n=375).
Fig.3: The Bronze Age dwelling place ‘Bodaweg’:a) The cultural layers are concentrated in several pits.b) The pits are dispersed randomly over the site (geomagnetical surveys, see Krause R., 2006).
Fig.4: Charcoal-rich layer from a pit (diameter = 2m, depth = 0,5m) at the excavation site ‘Bodaweg’. (Krause R., unpubl.).
Fig.2: The Bronze Age fortified hilltop settlement ‘Friaga’ (Krause R., 2006):a) 3D-model by Martin Schaich, ArcTron Dokumentation, Altenthannb) Occupation layers.
Fig.1: Investigation area in the Montafon (Bartholomäberg, Vorarlberg, Austria).Excavation site 1: The Bronze Age hilltop settlement ‘Friaga’ (940m a.s.l.)and site 2: The Bronze Age dwelling place ‘Bodaweg’ (980m a.s.l.),with the nearby mire ‘Tschuga’ (1200m a.s.l.). Several copper ore deposits are located at Bartholomäberg and Silbertal (Krause R., 2006 modified).
Middle Bronze Age 16th/15th
century BC
Iron Age 5th/4th
century BC
Early Bronze Age 19th/18th
century BC
Middle Bronze Age 14th/13th
century BC
Early Bronze Age 18th/17th
century BC
Material and Methods18 soil samples were systematically collected from the site ‘Bodaweg’ with a standardized volume (10 litres; see details in Tab.1). Carbonised plant remains were extracted using standard flotation technique. Approximately 100 charcoal pieces were randomly collected and analysed from each sample (Tab.2).
a b
a b
Spruce
(Picea)
Fir
(Abies)
Tschuga
Age of the burned deciduous wood
0%
10%
20%
30%
40%
50%
≤10 11-20 21-40 41-60 61-80 81-100 >100 n.s.
age class [years]
MBA 'type b' filled pits MBA 'type a' settlement pits EBA 'eba' pits
Age of the burned coniferous wood
0%
10%
20%
30%
40%
50%
≤10 11-20 21-40 41-60 61-80 81-100 >100 n.s.
age class [years]
MBA 'type b' filled pits MBA 'type a' settlement pits EBA 'eba' pits
ba
Bar
thol
omäb
erg
Bod
aweg
Sam
ple
volu
me
[l]
Sam
ple
num
ber
Pic
ea/L
arix
cf. A
bies
Fag
us s
ylva
tica
Ace
r sp
.
Que
rcus
sp.
Tili
a sp
.
Pin
us s
ylve
stris
Cor
ylus
ave
llana
Aln
us s
p.
Bet
ula
sp.
Bet
ulac
eae
inde
t.
Mal
oide
ae in
det.
cf. C
lem
atis
cf. E
uony
mus
Pin
acea
e in
det.
Dec
iduo
us in
det.
inde
t.
Tot
al c
harc
oal
wei
ght >
2mm
[g]
Ana
lyse
d ch
arco
alw
eigh
t >2m
m [g
]
Ana
lyse
d ch
arco
alpi
eces
Dec
iduo
usN
mD
Dec
iduo
usm
D [c
m]
Con
ifero
usN
mD
Con
ifero
usm
D [c
m]
MBA type 'b' 10 1 78 · · · · · · 20 · · · · · · · 2 · 20,6 3,1 50 11 5,77 39 6,01MBA type 'b' * 10 7 90 · · · · · · 10 · · · · · · · · · 41,1 4,1 50 5 4,40 45 6,33MBA type 'b' 10 11 74 · · 1 · · 2 14 · · 3 · · · 2 4 · 5,0 2,0 100 19 4,32 73 4,32MBA type 'b' 10 16 65 · · · · · 1 21 6 7 · · · · · · · 104,1 16,1 100 34 4,41 66 5,48MBA type 'b' 10 18 39 · · 3 2 · · 39 · 8 · 9 · · · · · 19,1 4,7 100 61 5,84 39 6,08MBA type 'b' 10 23 51 · · · · · · 24 22 · · 3 · · · · · 19,7 6,7 100 49 4,98 51 5,73MBA type 'b' 10 24 50 · · · · · 4 20 25 1 · · · · · · · 95,5 11,9 100 46 7,30 54 7,66MBA type 'b' 10 28 58 · · · · · 2 29 9 · · · · · · 2 · 61,0 5,3 100 40 6,66 60 6,64
MBA type 'a' * 10 2 84 3 9 · · · 2 · · · · · · · 1 1 · 20,2 3,5 100 10 4,95 90 5,53MBA type 'a' 10 4 83 · · · · · · · 6 7 2 · · · · 2 · 50,1 5,5 100 17 4,88 83 3,99MBA type 'a' 10 12 59 · 3 · · · · 10 · 3 1 9 · · 5 10 · 2,2 1,6 100 33 2,80 61 2,98
EBA type 'eba' 10 8 89 · 2 4 · · · · · · · · · · · 2 3 40,4 7,3 100 6 4,33 87 6,49EBA type 'eba' 10 9 81 2 4 4 · · · · · · · · · · 1 8 · 15,8 4,9 100 12 5,54 81 5,97EBA type 'eba' 10 10 59 10 6 · · · 1 · · · · 3 · 1 19 1 · 5,3 3,1 100 9 5,11 86 5,16EBA type 'eba' 10 13 56 8 28 · · 8 · · · · · · · · · · · 2,6 0,8 25 9 5,83 16 5,13EBA type 'eba' 5 39 46 · 34 2 · · · 4 · · · 2 4 · · 8 · 4,9 3,7 50 27 5,46 23 6,33
[%]
Sum 155 all 507,6 84,3 1375 388 5,37 954 5,52
EBA Early Bronze Age type 'eba' pits N Number * 1 of 2 samples MBA Middle Bronze Age type 'a' settlement pit type 'b' filled pit mD mean Diameter
mountain mixed forest pioneers others
Bartholomäberg BodawegBronze Age Period Early Middle MiddleType of pit type 'eba' type 'a' type 'b'Samples 5 4 9Sample volume [l] 45 40 90
CerealsHordeum vulgare · 2 6Hordeum sp. · · 2Cerealia indet. · · 1Triticum spelta (spikelet fork) · · 1
Gathered plantsPrunus spinosa · 1 ·
Rubus idaeus 11 3 ·
Sambucus nigra 1 2 1Sambucus sp. · 1 ·
Wild plantsAvena sp. (awn fragment) · · 1Chenopodium sp. · 3 ·
Fabaceae 1 · ·
Galium sp. · 1 ·
Polygonum aviculare · · 1Silene sp. 1 · ·
Solanum nigrum 1 · ·
Spergularia sp. · · 1Woodland
Picea abies (needle fragment) · 1 ·
Bronze Age
Identified charred plant remainsDiaspores and (others)
