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 Association for Tree-Ring Research |
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Dendroindication of synchronous (asynchronous) trends in productivity in middle-taiga of Arkhangelsk region, Russia Andrei I. Beliakov The conception of landscape dendrochronology as a new direction
in physical geography which theory and methods are based both
on geographical and dendrochronological principles has been introduced
in various geographical researches carried out by the Chair of
Physical geography and Landscape Studies. One of the most important
problems in modern landscape studies is the spatio-temporal synchronous
(asynchronous) processes in landscapes. Following the above mentioned
conception dendrochronological method which is known to evaluate
productivity - the main indicator of functioning in forest landscapes
has been applied to solve that problem. Valuable morphological and anatomical features of trees used for dating and reconstructing snow avalanches in the Swiss Alps and the Argentinean Andes Alejandro Casteller (1/2), Ricardo Villalba (2), Andrea Mayer
(1) Snow avalanches are a major disturbing factor of tree-growth in many alpine regions around the world. Through the application of dendroecological techniques, it is possible to date avalanche events with seasonal accuracy and to determine the area affected by them. However, tree responses to avalanches depend upon the species (conifers versus broadleaves), age, location along the avalanche gully, and magnitude of the disturbance events. As a first approach, study sites in the Swiss Alps were selected where avalanche records were available, and conifers (Picea abies, Larix decidua) are the dominant species. Cross-cuts, wedges and cores were taken and then analyzed using conventional dendroecological techniques. By this means, we could determine the specific reactions of the trees to documented events. Picea and Larix trees affected by avalanches are shorter in size. Some individuals are partially uprooted and present broken crowns. The main anatomical indicators of avalanches in Picea and Larix are: formation of compression wood, abrupt growth changes (releases and suppressions) and presence of resin ducts. For comparison, a survey of morphological and anatomical features was carried-out on the broad-leaved Nothofagus, the dominant species colonizing avalanche tracks in the Patagonian Andes. The sampling procedure and further analysis were similar to that applied on the samples from the documented sites in the Alps. Prostrate Nothofagus trees are common along the avalanche gullies. Scars are present in trees located in the tracks and bordering it, facing upslope in all cases. The main anatomical indicators in the wood of Nothofagus species are: formation of tension wood and abrupt growth changes. The reactions of trees to avalanches differed among conifers and broadleaves, but some common indicators are found (i.e. reaction wood, growth changes, scars). Nevertheless, the type and intensity of the reaction might vary depending on the type of avalanche, properties of the transported material, site conditions and on the plasticity of the species against the disturbances. Recovery of trees after rock fall events in subalpine spruce forests Andrea Foetzki, Martin Jonsson, Matthias Kalberer, Holger
Simon, Tor Lundström In subalpine spruce forest stands near Davos, Switzerland,
at an elevation of 1650 to 1800 m a.s.l., test sites endangered
to rock fall events were chosen for in-situ impact tests to simulate
rock fall. These tests were conducted within the framework of
an EC project (RockFor) in the summer of 2003. Stem disks of
the tested spruce trees (Picea abies) were taken at breast height.
Rock fall frequency in these forest stands will be estimated
by investigating the old injuries caused by rock fall found in
the stem disks. Growth of the trees and decrease in growth after
rock fall will be measured by means of dendrochronology. Contributions to the ecology of Common beech as derived from tree-ring analyses Christoph Dittmar (1) and Wolfram Elling (1) The title in more illustrative words: What can tell us tree
rings of Common beech about its ecology? In our contribution,
this question will be distributed and answered in several portions,
which demonstrate that tree-ring - actually dendroecological
- analyses are valuable tools to find out more about the ecology
of a tree species. At the Department of Forest Science and Forestry
of the Weihenstephan University of Applied Sciences and the Department
of Soil Science and Soil Geography of the University of Bayreuth
numerous tree-ring data were collected from different sites throughout
Europe. A current centre of study are beech sites at the northern
border of the Alps (Southern Germany). This data and their evaluation
are the base of our presentation. For the interpretation of tree-ring
variations continuous and dis-continuous time series analyses
were applied. For this intention meteorological, phenological,
crown condition and ecosystem water balance data are used. STREAM EROSION AND REGRESSION OF ESCARPMENTS Cesare MERLINI, Manuela PELFINI & Maurizio SANTILLI The valley slopes are often subject to strong erosion because of the removal of material from their bases due to the streams activity. In this work, a case of escarpment regression due to stream erosion was studied. The study area is the upper Valle del Gallo (upper Valtellina, Central Italian Alps), whose valley-bottom is entirely occupied by wide debris flow fans. The fluvial activity eroded the fan toes originating escarpments up to 50 m high. The progressive regression of the escarpments affects the above fans surface covered by a mountain pine forest. Progressively the edge of the escarpments reaches the trees that begin to lean towards the riverbed. However, the trees react with formation of compression wood in the attempt to recover their stability, until they die with the exposure of the whole root collar. It was possible to study the erosion and regression rate of the escarpments considering both the distance of the trees from the edge of the escarpment and the number of rings with compression wood. Cores from some hundreds trees along some kilometres of escarpments were collected. The first preliminary results indicate a mean erosion rate of about 2,5 cm/yr. This value agrees with some radiocarbon datings carried out from previous studies, which estimate the time span of the erosive process. The riverbed deepening is 1,1-1,5 cm/yr. These values agree with the age of three recent fluvial terraces located few meters above the riverbed, whose minimum ages were obtained from the maximum age of the trees growing on them. The analysis of the samples is still in progress and will refine the exposed results. Innovations in Computer Based Tree-Ring Analysis Programs Constantin Sander Assessment of tree-ring variables is a time-consuming procedure. Scientists spend a major part of their work on sampling and measuring. During the past years, hardware and software development have made it possible to tremendously reduce this work load. For data recording, scanning systems like LignoVision and LignoScan make fast assessment of tree-ring and density data feasible. Besides tree-ring width, intra-annual variables like earlywood and latewood width as well as the corresponding density data can be recorded at the same time. New perspectives for data analysis are opened with TSAP-Win. Segment-wise cross-dating for example (as already offered by COFECHA) is now supported by graphical control and editing features. Earlywood and latewood can be measured within one turn and the resulting series can be easily edited graphically on the screen. Additional parameters like traumatic resin ducts, fire scars, irregular anatomical features and others can be stored with the data. Interaction of natural hazards and human impact at two sites at Simplon Clarissa Zurwerra & Klaus Felix Kaiser The Hittuwald is supposed to be the oldest larch forest of
the Swiss Alps. The forest protects the huts beneath from avalanches
and rock fall. It counts about 200 trees aging from 800 to more
than 1000 years. The site might enable the development of a continuous,
perhaps eleven centuries long, record to study climatic fluctuations,
geomorphic processes, ecological alterations, and human interactions
such as pasturage and cutting. The historical as well as the
recent conditions of the site are quite promising. Overuse of
the downslope parts by pasturage was the main problem until 1930.
Also natural hazards such as avalanches and rock fall have deteriorated
Hittuwald for centuries. The second site, Brunnstauden, is located
further north crossed by an avalanche range. The pine-larch forest
stand shelters the Simplon Pass road. A dam was built above the
forest in the mid 1980s to increase protection. Reconstruction of dimension, frequency and pressure of past avalanche events by means of dendrogeomorphological methods and avalanche simulation Daniela Kasbauer¹, ², Andrea Mayer¹, Kurt Nicolussi³ Many studies have been carried-out to reconstruct the dimension and frequency of past avalanche events with the use of dendrogeomorphological methods. But less information is given about the pressure of past avalanches on trees, which is of great concern to reforestation and land use planning. Therefore, the aim of this study is to link the practical dendrochronology and the abstract avalanche modeling to close this gap. Dendrogeomorphology as a part of dendrochronology, allows us to reconstruct past avalanche events, which have not been recorded due to the absence of monitoring or the fact that the area is still unpopulated. Avalanches cause different growth signals in conifer trees, such as compression wood, scars, increasing or decreasing growth rates or resin ducts. To verify detected avalanche events in the annual growth rings, historical data and the knowledge of avalanche winters like 1999 provide valuable data. So far avalanche models do not include the parameters tree or forest, but can give us information about dimension and pressure of avalanches. In the main damage areas of the avalanche path "Hüttnertobel" near Gortipohl in the Valley Montafon/AUT 130 samples, cores and discs, mainly of Picea abies (Norway Spruce) have been collected and analysed for growth signals which can be caused by avalanche events. Based on the 1999 avalanche event in the study area "Hüttnertobel" the daily snow-layer increase data of the last decades was calculated based on nearby meteorological stations. By this, we can model the pressure and the dimension of the avalanches. As one result, we will be able to reconstruct the past avalanche activity in areas that were not documented and estimate the pressure those avalanches had on the trees. This will provide information on tree stability in avalanche paths and is therefore important knowledge to protection forest care and danger zones planning in areas where settlement area is scarce. EXAMPLES OF LANDFORMS DATING IN USE OF TREE RINGS (MALA PANEW MEANDERING RIVER) Ireneusz Malik Mala Panew meandering river flows crossing the sandy area
in the Southern Poland. Banks and floodplain are covered mainly
with Alnus glutinosa, higher terraces are covered with Pinus
sylvestris. Dendroclimatology of Toona ciliata in Eastern Australian Rainforests I. Heinrich & J.C.G. Banks Tree ring chronologies have been utilized to reconstruct the
variability of past climate in many regions of the world, particularly
in North America and Europe. In general, dendroclimatology has
not been widely applied in tropical forests and in particular
even less so in the Australian tropics due to the extreme rarity
of species producing anatomically distinct annual growth rings.
Furthermore, most Australian tree species (Eucalypt & Acacia
spp.) exhibit rather strong opportunistic growth with non-annual
growth zones that are less suitable for dendrochronology. Only
under exceptional circumstances, i.e. when trees grow in mountain
regions or in strong monsoonal climate have annual tree ring
chronologies been achieved. In mainland Australia, dendroclimatological
studies have been conducted with preliminary results indicating
that various Australian tree species are suitable for reconstructing
climate patterns. But no long-term annually resolved climate
proxy tree ring records do exist for mainland Australia yet.
Spatial differences and temporal patterns of ring-width and density chronologies of the mountain forests of northern Central Asia J. Block, V. Magda, D. Ovtchinnikov, A. Kirdyanov, U. Treter During the last 10 years, a dens network of tree-ring sites
was established in northern Central Asia. Samples were taken
from about 150 sites in southern Siberia and Mongolia. Most of
the sites were located in the mountain ranges of the Republic
of Altai, Tuva and Mongolia. In all regions we tried to take
samples at the local lower and upper tree-line. Besides the analyses
of the tree-ring width we tried also to establish and analyse
a network of tree-ring density sites. Regeneration dynamics of Norway Spruce (Picea abies L.) on a subalpine meadow near the treeline in Sedrun, Kt. Graubünden Jacqueline Bolli (1), A. Rigling (1) & H. Bugmann (2) Because of minor commercial value, some of the former agriculturally
used grasslands in the Swiss mountain areas near the treeline
have been abandoned recently and undergo a process of tree invasion.
Such meadows provide a unique opportunity to study natural regeneration
and growth of Norway spruce near the treeline. Using dendrochronological
methods, tree establishment and growth dynamics were studied
on a south-facing, abandoned meadow 1900 m above sea level in
Sedrun, Kt. Graubünden. Further, vegetation and soil patterns
were investigated and compared with the recolonization areas
on the study site. The main objective of this study was to get
an insight into important factors and processes which led to
the regeneration patterns we find today on this site. Determination of D/H ratios of nonexchangeable hydrogen in cellulose: Development of a new on-line method based on the cellulose-water exchange reaction Marc Filot Cellulose contains 70% carbon bound hydrogen, which is isotopically
not exchangeable and 30% of exchangeable hydrogen in from of
hydroxyl groups. The hydroxyl oxygene exchanges with the environmental
water and is not an usful indicator of the D/H ratio of the water
used by the plant during synthesis of cellulose. Two principles
have been discussed to obtain the D/H ratio of the nonexchangeable
hydrogen in the cellulose. The technique most commonly used involves
nitration of cellulose. In such a treatment the hydrogen of the
hydroxyl groups is replaced by the hydrogen free group of NO2.
The resulting cellulose nitrate is then analyzed for the D/H
ratio of carbon bound hydrogen. Dendrogeomorphological research on thermokarst depressions in western Siberia Mirko Krabisch & H. Strunk Tree-ring analysis and cross-dating provide the possibility
of exact dating of the development of thermokarst. Together with
additional investigations of soil, vegetation, and peat cover
as well as long-term temperature measurement we will be able
to clarify the origin and the nature of thermokarst. Lateglacial tree-ring chronologies - A high resolution archive of the past Schaub M. (1/2), Kaiser K.F. (1/2), Kromer B. (3), Friedrich
M. (4) During the last glacial maximum (approx. 20,000 years BP),
Alpine glaciers formed numerous lateral drainage channels on
the Swiss plateau. Adjacent to the then existing nunataks (e.g.,
Uetliberg), drainage channels were formed such as the valleys
of Sihl and Reppisch in the vicinity of Zurich. Mass movements,
precipitation and melt water filled the channels with predominantly
loamy sediments. These developed into huge archives containing
subfossil pines (Pinus sylvestris) and other macro and micro
remains. Compression Wood Formation And Growth Ring Structure in Picea abies [L.] Depending on Selected Site-related Factors, Detection of Compression Wood by Its Spectral Properties in Reflected Light Philipp Duncker Introduction Different studies have shown that the formation
of compression wood is a negative gravitropic reaction of the
coniferous tree. It is interpreted as serving the tree to recover
from a displacement in order to regain its original orientation
in space. For the stem this would be the vertical orientation
which it can hardly regain. The observed correction is often
limited to the apical meristem leading to the appearance of a
sweep. Therefore, compression wood formation can be considered
being a reaction to an external stress putting a strain on the
tree. A profound knowledge of compression wood distribution could
lead to a better understanding of the interaction of ecological
factors and the growth or reaction of trees in response to them.
In this study it is investigated which potential external factors
may cause a displacement and consequently compression wood formation.
Trees from sites with different slope and exposure to the prevailing
wind direction are examined for their compression wood distribution
as well as eccentric radial increment. The compression wood distribution
in stems of Norway spruce is described and it is analysed whether
there is a inter-annual time series in the formation of compression
wood. Competition between Pinus silvestris L. and Quercus pubescens Willd. in the Swiss Rhone valley Pascale Weber (1), Harald Bugmann (2), Andreas Rigling (1) Competition between Scots pine (Pinus silvestris L.) and Pubescent
oak (Quercus pubescens Willd.) was investigated to better understand
the pine decline in the Swiss Rhone valley. The aim was to predict
the role deciduous trees will play in low-elevation pine-forests
in the future. The record of debris flow activity in Mugo pine rings. Tatra Mts., Poland Ryszard J. Kaczka The debris flows are one of the main processes modeling the
high mountainous slopes. The debris flow in Dolina Gasienicowa
on the Zólta Turnia slope is one of the largest in Tatra
Mts. The fan is covered by mugo pine (Pinus mugo) which could
be the only source of dendrochronological information about the
debris dynamic. C and O isotope ratios in tree rings, an indicator for the impact of NO2 and Ozone on plants R. Siegwolf, Matthias Saurer Along with other air borne substances ozone and nitrogen emissions have increased considerably during the last three decades. The relevance of nitrogen deposition in forest and grassland ecosystems has become increasingly important. Besides NH3 emissions from agricultural activities, the main sources of NOx compounds are combustion processes like traffic exhausts, industry or heating activities. Today atmospheric NO2 depositions represent a considerable source of nitrogen for plants, with concentrations reaching higher than 100 nL L-1 in the vicinity of NOx emission sources. This can contribute significantly to the plant nitrogen budget. Via diffusion through the stomata, the NO2 enters the substomatal cavities where it is rapidly dissolved and incorporated through various biochemical steps. Its incorporation in the plants results in physiological changes, which are reflected in the 13C and 18O isotope signature. Photosynthesis and growth were stimulated by NO2. While NO2 has an ambiguous effect (fertilizing and toxic) ozone has been shown to be detrimental on plants. However, before any visible symptoms can be found the 13C values of bulk plant material are increased, which cannot be explained by gas exchange characteristics (ci/ca). Instead an increase in PEP carboxylase activity is found, which accounts for most of the increase in 13C. The impact of NO2 and ozone on plants must be considered in isotopic studies of tree ring material, in particular in urban areas and during periods with high concentrations of reactive compounds. First results indicate that these substances alter the isotopic composition in tree rings besides the climate. Stable isotope ratios in tree rings of living Scot pine near Reichwalde opencast mine in Lusatia (East germany) Ralf Wagner, Tatjana Boettger, Ilse Boeren, Michael Friedrich Related to isotopendendroclimatic studies of Late Glacial fossil pine forest excavated under the peat deposition at Reichwalde opencast mine, a number of boring cores from living pine trees (Pinus sylvestris L.) have been sampled in a location near the village Rietschen. In spite of relatively short distance the chosen site varied from moist swampy to dry and sandy dune. Selected cores of these have been investigated for their carbon and oxygen isotope variation. The results show that ?13C values of the tree ring cellulose increase continuously in the last 50 years. This effect can be mainly explained and quantified by anthropogenic impact in relation to the open cast mine activity. Feasibility study of a Dendrochronological time row in French-Polynesia, South Pacific Reto Widmer I was particularly motivated to perform analysis in a country,
in which no one had done any dendrochronologal work. I undertook
this pioneer work on the basis of 3 journeys to French Polynesia
in the years 2002 and 2003, during which I spent a total of 3.5
month for field work. Reconstructions of Northern Hemisphere temperature: How they measure-up when undressed David Frank(1), J. Esper(1), R. Wilson (2) The desire to reconstruct large-scale climate has resulted in four millennial length reconstructions(1) with annual resolution, that are deemed to be representative for large areas of the Northern Hemisphere. These reconstructions either depend solely upon tree-ring data or utilize a combination of tree-ring data in combination with other proxy data (e.g., ice cores, corals). Examination of these records reveals both similarities and differences in reconstructed climate variations over the past millennia. Major differences include the transition from warm conditions associated with those of the Medieval Warm Period into cool conditions associated with the Little Ice Age, and also the amplitude in degrees Celsius between warmest and coldest time periods. Despite these differences, a high degree of similarity is found to exist when the multi-decadal variations are considered. Understanding and resolution of these issues are critical as modeling studies are increasingly using these reconstructions for calibrations and determining the climatic sensitivity to solar, volcanic and anthropogenic (CO2 and tropospheric aerosols) forcings. Here we present analyses, based on two papers(2), of which factors are likely responsible for these differences and similarities, and how much these factors might account for in degrees Celsius. In short, relatively ignored methodological differences, including how the tree-ring data are detrended and how reconstructions are 'fit' to instrumental data, are crucial to the assessment of past temperature change. 'Uncertainties' introduced by these methodological differences can easily approach 0.5 C, which is on the order of the entire temperature amplitude for the past millennia. (1) These millennial reconstructions are: (2) These papers are: A 1200-year alpine summer temperature record Ulf Büntgen (1), J. Esper (1), D. Frank (1), M. Schmidhalter
(2), K. Nicolussi (3), K. Treydte (1)
Research in atmospheric circulation patterns, climate variability
and reconstruction for the Alps, Europe and the North Atlantic
area has a long tradition. Significant progress has recently
been made in understanding European climate variations over the
past 150 to about 500 years through studies of long observational
climate records, documentary evidence and other proxy data. However,
detailed knowledge of low-frequency European climate variation,
due to methodological and inherent limitations of most proxy
data and their poor replication prior AD 1500, is still missing.
Tree rings as a calibration tool for dynamic forest models Sophie Rickebusch Most forest gap models have been developed for trees which
are approximately in the centre of their altitudinal or latitudinal
distribution. Therefore, curves for growth response to climatic
factors, such as degree-day sum, are adjusted for values in the
middle of each species' niche. But how reliable are model curves
when dealing with extreme values? QUANTIFICATION OF SULFUR AND METALS IN PICEA ABIES BY LASER ABLATION ICP-MS T. Barrelet, U. Krähenbühl (Univ. Bern); A. Ulrich,
D. Bleiner (EMPA); LASER ablation inductively coupled plasma mass spectrometry
(LA-ICP-MS) allows spatial resolved analysis of solid samples
with superior detection power. This technique is already in use
for dendrochemical analysis: A few authors studied metal distribution
in living trees and some research on the radial migration of
heavy metals is available. Less is known about the behaviour
of non metals such as sulfur. The aim of the present study is
chiefly to analyse the spatial distribution of sulfur in tree
rings (from metabolism studies, a likelihood of constant recording
of sulfur in wood can be assumed). The data obtained will be
compared to the sulfur profiles found in peat cores from Duedingen
(580 m a.s.l., Swiss Plateau), where the concentrations correlate
with the sulfur dioxide emissions in Switzerland during the last
century, and Mauntschas (1900 m a.s.l., Engadin), where they
do not. Using a 5 mm increment borer, six trees were sampled
at each site, as well as in Frieswil (Swiss Plateau) a site without
peat bogs, but situated at a medium altitude of 740 m a.s.l.
Combining remote sensing and tree ring analysis to study vegetation-climate relations in Southern Africa Trouet, V., Coppin, P., Beeckman, H. Proxy climatic data offer a potential solution for the limited
spatial and temporal coverage of climate stations in Southern
Africa. By integrating proxy data sets, the spatio-temporal character
of climate studies can be optimalised. This study investigates
the possibility to integrate broad-scale remote sensing and tree
ring analysis for the study of the response of the miombo woodland,
characterized by a tropical wet and dry climate, to climate in
Southern Africa. Investigation of the interactions between pines and beeches in two-layer mixed stands using methods of tree ring research Wolfgang Beck Within the framework of a multi-disciplinary study of the
ecology of two-layer mixed pine-beech-stands in the north-eastern
german lowlands new findings regarding the interactions between
these tree species were gained by application of methods of tree-ring
analysis. Spatio-temporal relationship between tree ring width, 13C and 18O - examples from high mountain regions Treydte, K. (1), Esper, J. (1), Schleser, G.H. (2), Helle,
G. (2), Frank, D. (1), Büntgen, U. (1) In recent years an increasing number of studies on stable
carbon and oxygen isotopes in tree rings were published with
the aim of evaluating their potential for climate reconstruction.
While 13C variations capture temperature and/or humidity variability
through changes in the stomatal conductance, 18O serves as an
archive for isotopic changes in up-taken water. If trees use
water derived from local precipitation, the oxygen signal of
the rainfall or snow, and therefore temperature or circulation
patterns can be reconstructed. However, oxygen values are further
regulated by changes in the stomatal conductance and transpiration
effects. Tree ring width integrates numerous external and internal
influences, and is known as a suitable proxy for temperature
or precipitation variations, especially when extreme sites with
mainly one climatic factor dominating tree growth are selected.
So, on one hand, the parameters should be independent because
of different dominating external factors and internal mechanisms,
but on the other hand, environmental conditions, which influence
all parameters simultaneously, occur. However, few studies exist
that systematically investigate relationships between these three
tree ring parameters, using multiple sites, similar material
and reasonable replication. Dendroecological study of four Pinus cembra sites in the Engadin, Switzerland Rolf Niederer (1), Jan Esper (1), Peter Bebi (2), Kerstin
Treydte (1) & David C. Frank (1) Plots of Pinus cembra were sampled in different ecological
settings in the Engadin, Switzerland. These plots includ all
age classes, with over 140 cores sampled per site. Two sites,
one with a northern (Muottas) and the other with a southern (Silvaplana)
exposure, are located at upper timberline near St. Moritz. An
additional northerly exposed site (Celerina), located about 400
meters lower than the north exposed timberline site was sampled.
The fourth site, Tamagur, was chosen because some of the oldest
Pinus cembra trees were thought to grow there, and is located
about 43 kilometers north from the other three sites. The chronology
from this site is the oldest, spans 1478-2002, and has a mean
segment length of 206 years. |
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THE USE OF TREE AGE FOR ESTIMATING THE RATE OF LATERAL MIGRATION OF THE MALA PANEW RIVER CHANNEL, SOUTHERN POLAND Dariusz Ciszewski The age of trees, which growth in XX century paleochannels and on point bars has been determined in the upper reach of the Mala Panew River in eastern part of the Silesia Lowland, southern Poland. Six meander bends, which shifted markedly during 100 years, as maps 1:25 000 of 1883 and of 1984 indicate, were selected for investigations. In these bends paleochannels are relatively well preserved. The age of the oldest tree, which grows in every paleochannel gives the minimum age of this form. Further, the minimum rate of lateral river bank migration within a particular river bend was calculated on the base of this minimum age and the distance of every paleochannel from the present river bank. The minimum rate of the river bank migration varies between 0.2 and 0.4 m/year and is generally 20-30% lower if compared with channel shifting on maps, 0.4 - 0.6 m/year. Moreover, age of sediments obtained from dating by heavy metals in some meander bends is similar to that obtained from dating by trees and maps. These preliminary results show, that the tree age gives raw estimation of the channel migration rate because of tree succession which, is usually several to 12 or so years delayed. The best estimation of the paleochannel age give trees growing at the inlet of the paleochannel which, is relatively quickly filled with sediments. Potentialities, difficulties and limits in reconstructing giant chestnut chronologies Patrick Fonti, Patrik Krebs and Marco Conedera Chestnut (Castanea sativa Mill.) and the Southern part of
the Swiss Alps are close related since the Roman's arrival. Imported,
planted and managed for two millennia, chestnut has been a privileged
witness of the history of a territory strongly influenced by
men activities. Nevertheless, this species has been seldom used
in dendrochronology because of both specie related and management
related influences in the tree rings. HOW A NEW YARD IN A HIGH MOUNTAIN AREA CAN AFFECT THE TREES GROWTH? Manuela PELFINI (1), Maurizio SANTILLI (1), Marco BARSANTI
(2), This work aimed to estimate the impact of anthropic activities in an high mountain area (upper Valtellina, Sondrio) used since 1920s for hydroelectric power production. Recent works in the hydroelectric system brought, in 1998, to the opening of a yard located in an area with great natural value, partially within the Stelvio National Park. The research involved dendrochronological surveying on the mountain pine forest surrounding the yard area. Samples from trees locates at various distances from the yard and in different conditions of disturbance were taken in order to estimate how the yard activity affect the trees growth. Dendrochemical analyses were carried out too. Nearly half of the analyzed samples clearly show a growth decrease starting from 1998, due to the huge increase of dust in the air. Most of the damaged trees live close to the disturbance source (limit of the yard and sides of the access road), while in many trees more than 30-40 m far away there is only little or no growth reductions. Anyway, not all the samples close to the yard show a strong growth decrease, probably due to the lower competition derived by the cutting of surrounding trees. Moreover, many affected trees show a recovering of the normal growth in a short time (3-4 years). The dendrochemical analysis shows a lessening of the lead concentration in the period 1992-1996, and an increase in the period 1997-2003. The first lessening is attributable to the new fuels, while the increase in recent years could have been caused by the yard activity. New state of the stable isotope and dendrochronological studies on a 1000 years pine (Pinus sylvestris L.) tree-ring chronology at the alpine tree limit in the Khibiny Low Mountains, Kola Peninsula, north-western Russia T. Boettger, J. M. Kononov, M. Friedrich Climatic conditions of Late Holocene for the north-west of
Russia have been reconstructed on the basis of 1134 years pine
tree-ring chronology from Khibiny Low Mountains in the central
part of Kola Peninsula. The chronology consists of 259 subfossil
and living Scots pines (Pinus sylvestris L.).from the modern
timberline. The subfossil samples were discovered in the diapason
from 100 till 140 m above modern timberline. The increment fluctuations
of the trees show a tight relationship to the observed temperature
in summer season in the period of 1923-2000. The variability of inter- and intraannual wood structure of tropical tree rings Esther Fichtler Part of the PhD study: Increment and age determination of
tropical trees by standardised macroscopical tree ring analysis
(Sponsored by the Scholarship Programme of the German Federal
Environmental Foundation) Rural buildings, economic history and Dendrochronology in the cultural scene of Upper-Weser region Dr. Volker Gläntzer, Erhard Preßler Since 3 years the Regional Country Office For Preservation
Of Monuments within the project "Rural buildings, economic
history and preservation of monuments in the Weser-district of
Braunschweig" is examining the small, but -considering building
research- the very important cultureregion of Upper-Weser; and
here mostly and especially rural buildings dated back to borders
of time, when registration is still possible. Dendrochronology
is supplying with more informative data. Management of project: Niedersächsisches Landesamt für
Denkmalpflege, Hannover The influence of NOx on the 15N/14N-variations in tree rings near a motorway M. Saurer (1), Paolo Cherubini (2), Bruno de Cinti (2), R.
Siegwolf (1) Forests are increasingly affected by nitrogen deposition due to the large emissions of NOx from traffic and NH4 from agriculture. This is a serious long-term problem as the nitrogen is accumulating in the soils and does affect the ecosystems in many ways. Tree ring analysis may help to evaluate the time course of nitrogen deposition in forests, whereby ?15N isotope analyses may give an indication on the importance of different sources to the total nitrogen load. In this study, we investigated 3 sites at different distances (20 m, 150 m, 1000 m) from a motorway constructed in Switzerland in 1965. We sampled 4 Picea abies trees per site, whereby - in order to remove soluble nitrogen compounds - we extracted the tree ring cores with hot water and alcohol-toluene before the isotope analysis. The ?15N values of the tree rings were strongly increasing after 1965 at the site closest to the motorway, indicating the uptake of NOx from car exhausts, although the signal was not present in all 4 trees. Similarly, the total nitrogen content in the tree rings increased at this site after 1965. We found it difficult to estimate the amount of nitrogen deposition due to strong variations between trees from the same site, but we were able to reconstruct the time course of the isotope signal of NOx from the traffic for the period 1965 to the present. Biological vs. climatic influences on the oxygen isotope ratio of tree rings Christina Reynolds (1), Matthias Saurer (1), Rolf Siegwolf
(1), Christian Körner (2) Trees are climate proxies. As living organisms, they respond physiologically and physically to environmental conditions and record some of this information in their annually resolved growth rings. This does not only hold for ring-width and density, but also for the stable isotopes laid down in the wood. We studied seasonal oxygen isotope fractionations occurring before the formation of wood in 19 trees in a mature temperate forest. On a seasonal scale, ?18O of leaf water reflects source water uptake and evaporative enrichment for a given time-point. ?18O of leaf organic matter, on the other hand, integrates external conditions over a longer period of time. Over the course of the growing season, this signal is transferred and stored in tree rings in the form of cellulose. Our results help establish a quantitative relationship between the isotope signals of intermediate photosynthetic compounds and help better relate ?18O of tree-rings to physiological processes and ultimately climate. Tree-ring chronology of Picea abies in the Carpathian Mountains (Poland, Ukraine). Recent development and climatic analysis Ryszard J. Kaczka, Magdalena Opala, Karolina Ptaszek The paper presents the preliminary results of dendroclimatological
investigation of spruce in the Carpathian Mountains. Carpathians
are one of the major and after the Alps the most extensive mountain
system of Europe. Spruce (Picea abies (L.) Karst.) predominates
in the upper mountain forest zone (as high as 1,500 m. a.s.l.).
Although some local chronology from this region exist, Carpathians
are still a gap in dedrochronological research of Europe. The
aim of study is to develop the chronology for main massives of
Carpathins, which do not form an uninterrupted chain of mountains
and to compare the relationship between individual chronology
and climate conditions from eastern to western boundary of Carpathian
Mountains. Isotope studies along a high-elevation transect on the Tibetan Plateau Jussi Grießinger (1) & Achim Bräuning (2) The mountain areas of High Asia are generally regarded as
a climatically sensitive high-altitude area. During the last
years, considerable progress has been achieved in climate reconstructions
based on stable isotopes in wood cellulose from subalpine sites,
namely in the Karakorum (Treydte 2003) and on the Tibetan Plateau
(Helle et al. 2002). In addition, the vast high altitude plateaus
of Tibet are playing a major role as a mainspring of the Indian
and East Asian monsoon circulation. In eastern Tibet, more than
80% of the annual rainfall is falling during the summer monsoon
season between June and October. As a consequence, the water
which penetrates the soil surface is directly absorbed by the
plant roots without a long residence time within the soil system.
DENDROCLIMATOLOGICAL INVESTIGATIONS IN YAKUTIA, NORTH-EAST OF RUSSIA Anatoly Nikolaev The Republic of Sakha (Yakutia), which is situated in the
north-eastern part of Asia, is the largest region of Russia.
The territory of republic consists 3.1 mln km2. Dendroclimatological
investigations were made through two longitudinal (western and
eastern) and one latitudinal transects. The length of each meridional
transect from Tiksi to Yakutsk (western) and from Kazachye village
to Ust-Maya village (eastern) consists more than 1200 km. From
the west (Yakutsk) to the east (Oimyakon) the length is more
than 600 km. Climate extremes and growth response of Pinus cembra within the forest-alpine tundra ecotone Evelyn Selva and Walter Oberhuber Growth response of Cembran pine (Pinus cembra L.) to short-
and longterm climate variability was studied in the timberline
ecotone and zone of recent tree establishment on Mt. Patscherkofel
(2246 m a.s.l.). The study area, which is in the inner alpine
dry region of the Central Austrian alps (mean annual precipitation
<900 mm), is characterized by a continental climate with minimum
precipitation in winter and frequent occurrence of warm dry winds
(Föhn) in early spring. Growth variability at a small spatial
scale (<2 km2) was determined by taking c. 400 increment cores
at N-, S- and W-facing slopes stretching from 2000 to 2200 m. Stable isotope ratios in late wood of Picea abies from Engadine A.L. Carnelli, B. Ammann, J. Esper, M. Filot, M. Leuenberger, K.Treydte Calibration of the isotopic signature in tree rings with metereological
data is needed for accurate palaeoclimatic reconstruction. Studies
in the subalpine belt are scarce, in this on going project we
aim to compare the d13C and d18O isotopic ratios in cellulose
extracted from late wood of Picea abies Mill. growing at the
upper timberline with metereological data from a 10 km away station
(St. Moritz). Tree ring parameters such as width and density
were mesured as well to allow an evaluation of these proxies
in respect of their potential to extract temperature, precipitation
and relative air humidity. Two time windows of 50 years each,
i.e. 1946-2000 AD and 1800-1850 AD, are investigated. Dendrogeomorphological analysis of the enlargement of cracks at the Wellenkalk-scarp in the southern Thuringia Basin I. Sahling (1), H. GÄRTNER (2) & K.-H. SCHMIDT (1) The Wellenkalk cuesta scarp in the Thuringia Basin is characterised
by the occurrence of massive block displacements. Their initial
phase is marked by the formation of tension cracks. Until now,
dendrogeomorphological studies of corresponding movement rates
are rare. However, the study of affected trees offers many possibilities
for the reconstruction of past and recent mass movements, especially
using anatomical analysis of the growth-ring structure of affected
roots. A spatial high resolved climate reconstruction from recent and historical tree-ring data in the Rheinisches Schiefergebirge since AD1500 Dagmar Friedrichs & B. Neuwirth
The influence of drought on the wood structure of Pinus silvestris L. and Quercus pubescens Willd. in Valais, Switzerland. Britta Eilmann (2), Pascale Weber (1), Dieter Eckstein (2),
Andreas Rigling (1) In the inner-Alpine dry-valley the lower Scots pine (Pinus
sylvestris L.) forests are in change. While pine shows high mortality
rates, deciduous species, in particular Downy oak (Quercus pubescens
Willd.), are spreading. Increasing drought is one potential factor
for the pine decline in Valais, besides land-use change, insect
pests, pathogens and natural succession. |
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