TRACE Tree Rings Archaeology Climatology Ecology

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The event frequency per year for the five trigger zones indicates a relation between frequency and size of trigger area. However, no clear and significant relation was found with monthly precipitation data. Field observations showed the beginning of debris flows in this area within 5-10 minutes after the start of very high intensive rainfall of 50-100 mm/hr. Flow velocities of 3 – 10 m/s were measured. Periodicity analysis of response curves of the above mentioned area and other areas in the Bachelard valley indicate several peaks in wavelength of years (Fig.5). Three areas showed a remarkable peak around 11 years (De Redelijkheid 1988). However the data is too scarce to be of statistical significance for a climatological interpretation. No relation with data of the nearest climate station was found. Figure 5: Periodicity of debris-flows in the Bachelard valley (after De Redelijkheid 1988) Stabilizing phase of a rockglacier Surface forms of the studied rockglacier show fresh sharp ridges and clear boundaries, sparsely vegetated by grasses, shrubs and a few larches. These observations of fresh forms seem to indicate that the rockglacier became inactive recently. This interpretation implies that the moment of inactivation can be dated using the oldest tree on it, corrected for missing rings, colonization delay and response time of the rockglacier. The oldest tree counted 81 rings. Nine missing rings were identified by crossdating and by extrapolation of the ring width series to the tree’s pith at ground level. Colonization delay was estimated 20-30 years (based on McCarthy & Luckman, 1993; Winchester & Harrison, 2000). Response time was also estimated 20-30 years (Barsch, 1996). Hence, inactivation of the rockglacier was dated between 1850/1870. Inactivation of rockglaciers occurs when the mean annual air temperature (MAAT) exceeds - 2° C (Barsch 1996). The MAAT is known from the neighbouring village Ceillac at 1665 m. The MAAT for the rockglacier can be calculated with the specific temperature gradient for the Alps. The difference between the inactivation temperature of -2° C and the recent MAAT yields a temperature change of +3° C since about 1850, the end of the Little Ice Age. 41
This reconstructed temperature increase of 3° C seems extremely high in comparison with the same kind of data (Grove, 1988). Possibly the rockglacier was only cleared of vegetation in the Little Ice Age and afterwards it was revegetated. However, compared with the MAAT change in Ceillac over the last 40 years (1.5 to 2° C) the calculated value could be realistic over the time span in question (125 years). Conclusions Analysis of tree rings of trees on active landforms may enhance the understanding the dynamics of mass movement. Understanding development of landforms using tree ring eccentricity can only be successful with a good analysis of the terrain characteristics and verification with data not based on tree rings. Weather condition is one of many trigger factors in mass movement development. However, monthly and yearly data from local climate stations are not sufficient to explain the short-term dynamics of landforms in the studied area. Long-term climatic developments can be sustained by tree-ring dating of rockglaciers. References Alestalo, J. (1970): Dendrochronological interpretation of geomorphic processes. Fennia 105: 1-140 Assier, A. (1996): Glaciers et glaciers rocheux de l’Ubaye. Sabença de la valeia, Barcelonnette, 32 p Barsch, D. (1996): Rockglaciers, Indicators for the Present and former Geoecology in High Mountain Environments. Springer Verlag, Berlin-Heidelberg: 331 p Blijenberg, H. (1998): Rolling stones? Triggering and frequency of hillslope debris flows in the Bachelard Valley, Southern French Alps. Netherlands Geographical Studies 246: 240 p. Braam, R.R., Weiss, E.E.J. & P.A. Burrough (1987a): Spatial and temporal analysis of mass movement using dendrochronology. Catena 14: 573-584 Braam, R.R., Weiss, E.E.J. & P.A. Burrough (1987b):Dendrogeomorphologicalal analysis of mass movement: a technical note on the research method. Catena 14: 585-589 De Redelijkheid, M. (1988): Datering van Puinstromen in de Franse Alpen met Lichenometrie en Dendrogeomorfologie. Unpublished report, Universiteit Utrecht, Department of Physical Geography. Fritts, H. 1976. <strong>Tree</strong> <strong>Rings</strong> and Climate. Academic Press, London: 567 p. Grove, J.M. 1988. The little ice age. Methuen, Cambridge: 498 p. McCarthy, D.P. & B.H. Luckman (1993): Estimating ecesis for tree-ring dating of moraines: A comparative study from the Canadian Cordillera. Arctic and Alpine Research 25: 63-68 Meijer, F. & T. Wils (2001): Reconstructie van klimaatfluctuaties. Unpublished report, Universiteit Utrecht, Department of Physical geography. Overbeek, J. & J. Wiersma (1996): Puinstroomsystemen in de Franse Alpen. Unpublished report, Universiteit Utrecht, Department of Physical geography. 42
Page 1 and 2: Forschungszentrum Jülich in der He
Page 3 and 4: Schriften des Forschungszentrums J
Page 5 and 6: Bibliographic information published
Page 8 and 9: CONTENTS SECTION 1 ECOLOGY A. Bräu
Page 10: T. Vernimmen and U. Sass-Klaassen:
Page 13 and 14: Tree-ring studies in the Dolpo-Hima
Page 15 and 16: Rara MLD (Abies) Rara RW (Abies) Ts
Page 17 and 18: Cook, E.R., Krusic, P.J. & P.D. Jon
Page 19 and 20: Material and methods In the first p
Page 21 and 22: Correlations for all trees (no site
Page 23 and 24: Acknowledgements The authors wish t
Page 25 and 26: Results and interpretation Species
Page 27 and 28: Figure 3: Multitemporal maps of est
Page 30 and 31: SECTION 2 GEOMORPHOLOGY
Page 32 and 33: Zurich Geneva Study site Zermatt Fi
Page 34 and 35: lot of debris-flow events can be se
Page 36 and 37: Changes in growth rates and wood an
Page 38 and 39: Growth reductions and eccentricity
Page 40 and 41: 40% of all trees in the landslide a
Page 42 and 43: Figure 1: Location of study areas H
Page 44 and 45: Ai− rBi Eccentricity for year i i
Page 48: Shroder, J.F. (1980): Dendrogeomorp
Page 51 and 52: Temporal and spatial variability of
Page 53 and 54: 120 100 80 (Dlink/Dmax)*100 60 Uppe
Page 55 and 56: Figure 6: Results of stepwise clust
Page 57 and 58: Figure 8: Forest types and forest d
Page 59 and 60: The first principal component of a
Page 61 and 62: Figure 2: Correlations of the 1 st
Page 63 and 64: NAO and Tree Rings - A dendroclimat
Page 65 and 66: 5°E 10°E 15°E 50°N 45°N Figure
Page 67 and 68: The smaller bars show the number of
Page 69 and 70: a b c d Significant correlating are
Page 71 and 72: Neuwirth, B., Esper, J., Schweingru
Page 73 and 74: Unterspreewald,Brandenburg,Germany
Page 75 and 76: Unterspreewald, Brandenburg, German
Page 77 and 78: Leuschner, H.H., Delorme A. & H.-C.
Page 79 and 80: Figure 1: Location of the monitorin
Page 81 and 82: Figure 3: Examples of the distribut
Page 83 and 84: On the potential of cedar forests i
Page 85 and 86: At every site, two cores per tree w
Page 87 and 88: Maximum replications are reached in
Page 89 and 90: Schweingruber, F.H., Eckstein, D.,
Page 91 and 92: developed that can be used to study
Page 93 and 94: 4 3 2 1 0 -1 -2 normalized Schmidha
Page 95 and 96: This value is based on the fact tha
Page 97 and 98:
Stokes, M.A. & T.L. Smiley (1968):
Page 99 and 100:
The use of stable isotope dendrochr
Page 101 and 102:
3.0 2.5 Z74 2.0 1.5 1.0 0.5 0.0 3.0
Page 103 and 104:
Conclusions The combined stable car
Page 105 and 106:
The climatic signal in oxygen isoto
Page 107 and 108:
Results Figure 2 shows the raw ring
Page 109 and 110:
Secondly, the records are short and
Page 111 and 112:
Jouzel, J., Hoffmann, G., Koster, R
Page 113 and 114:
Although the difference between min
Page 116 and 117:
SECTION 5 PALAEO-ENVIRONMENTS
Page 118 and 119:
Results and discussion Of 59 oaks a
Page 120:
Acknowledgements This research was
Page 123 and 124:
Great efforts on small woods Analys
Page 125 and 126:
Some 250 of them - mainly beeches (
Page 127 and 128:
References Billamboz ,A. (1990): Da
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coefficient can be expected from in
Page 131 and 132:
country region covered by theCATRAS
Page 133 and 134:
Figure 2: Map of the Netherlands an
Page 135 and 136:
Jansma, E., Sass-Klaassen, U., de V
Page 137 and 138:
The aim of the current study is to
Page 139 and 140:
Figure 1: Map of archaeological sit
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0.8 correlation coefficient (r) 0.4
Page 143 and 144:
Acknowledgements We would like to e
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Figure 2: 17th century forgery (Mus
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1400 1450 1500 1550 1600 1650 1700
Page 149 and 150:
Table 2 - Average annual-growth ind
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Conclusion The data set we studied
Page 153 and 154:
Figure 1: Collapsed foundation (Pho
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A list of the archaeological sites
Page 157 and 158:
personal communication) believe tha
Page 159 and 160:
Table 4: Success rates of the dendr
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wood with no strong common tree-rin
Page 163 and 164:
Jansma, E. (1996): An 1100-Year Tre
Page 165 and 166:
Malacochronology, the application o
Page 167 and 168:
Fladen Grounds 100 m Norway 30 m UK
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higher with the chronology of growt
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0 140 200 growth index 120 100 80 6
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an underlying mechanism but demonst
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Witbaard, R., Jenness, M.I., Van de
Page 177 and 178:
TRACE 2003 Utrecht (NL) 1 st -3 rd
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TRACE 2003 Utrecht (NL) 1 st -3 rd
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Schriften des Forschungszentrums J
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Page 185 and 186:
Page 187:
Forschungszentrum Jülich in der He
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