scholarly journals Tree-ring reconstruction of March-June precipitation from the Atlas cedar forest of Mount Takoucht, Béjaïa (northern Algeria)

2021 ◽  
Vol 30 (3) ◽  
pp. e011-e011
Author(s):  
Said Slimani ◽  
Keyword(s):  
Tree Ring ◽  
Temporal Stability ◽  
Summer Precipitation ◽  
Early Summer ◽  
Late Winter ◽  
Climate Conditions ◽  
Northern Algeria ◽  
Dry Conditions ◽  
Tree Ring Reconstruction ◽  
Clear Shift

Aim of study: A March-June precipitation has been reconstructed for the period 1830-2015 using Atlas cedar (Cedrus atlantica Manetti) tree-ring records. Area of study: Atlas cedar forest of Mount Takoucht (Béjaïa, northern Algeria). Material and methods: Seasonal correlations were computed in order to identify the best period of the year for the climate reconstruction. The temporal stability of the tree-ring signal for precipitation was checked using the split-sample calibration-verification procedure. The reconstruction was performed using the transfer function method. Main results: The reconstructed data revealed high interannual to decadal variation in late winter to early summer precipitation. Wet conditions dominated during the 1830s and 1840s and were followed by sustained dry conditions during the mid-19th century, which registered two of the most severe droughts (1858 and 1869) over the period of reconstruction. Relatively moderate climate conditions marked the late 19th and early 20th centuries. A gradual return towards drier conditions was observed from the 1920s and reached high frequencies of drought around mid-20th century. After an exceptional prolonged wet period of 24 years (1966-1989), the reconstruction registered its highest frequency in extreme dry/wet events: the decade 1993-2002 recorded the highest drought frequency of the reconstruction, with the third most severe dry event (1999), while the last years were marked by a clear shift toward wet conditions. Research highlights: These findings provide relevant records on past climate variability in one of the rainiest areas in Algeria and constitute valuable knowledge for specific drought and wet periods monitoring in the region.

scholarly journals An 854-Year Tree-Ring Chronology of Scots Pine for South-West Finland

2014 ◽  
Vol 31 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Samuli Helama ◽  
Jari Holopainen ◽  
Mauri Timonen ◽  
Kari Mielikäinen
Keyword(s):  
Tree Ring ◽  
Ring Width ◽  
Summer Precipitation ◽  
Total Sample ◽  
Early Summer ◽  
The South ◽  
Tree Ring Chronology ◽  
The North ◽  
South West ◽  
The North Atlantic Oscillation

Abstract A near-millennial tree-ring chronology (AD 1147-2000) is presented for south-west Finland and analyzed using dendroclimatic methods. This is a composite chronology comprising samples both from standing pine trees (Pinus sylvestris L.) and subfossil trunks as recovered from the lake sediments, with a total sample size of 189 tree-ring sample series. The series were dendrochronologically cross-dated to exact calendar years to portray variability in tree-ring widths on inter-annual and longer scales. Al though the studied chronology correlates statistically significantly with other long tree-ring width chronologies from Finland over their common period (AD 1520-1993), the south-west chronology did not exhibit similarly strong mid-summer temperature or spring/early-summer precipitation signals in comparison to published chronologies. On the other hand, the south-west chronology showed highest correlations to the North Atlantic Oscillation indices in winter/spring months, this association following a dendroclimatic feature common to pine chronologies over the region and adjacent areas. Paleoclimatic comparison showed that tree-rings had varied similarly to central European spring temperatures. It is postulated that the collected and dated tree-ring material could be studied for wood surface reflectance (blue channel light intensity) and stable isotopes, which both have recently shown to correlate notably well with summer temperatures.

A tree-ring based reconstruction of early summer precipitation in southwestern Virginia (1750–1981)

2015 ◽  
Vol 64 (3) ◽  
pp. 243-256 ◽  
Author(s):  
A Dawson ◽  
D Austin ◽  
D Walker ◽  
S Appleton ◽  
B Gillanders ◽  
...  
Keyword(s):  
Tree Ring ◽  
Summer Precipitation ◽  
Early Summer

Dendroclimatology of high-elevation Nothofagus pumilio forests at their northern distribution limit in the central Andes of Chile

2001 ◽  
Vol 31 (6) ◽  
pp. 925-936 ◽  
Author(s):  
Antonio Lara ◽  
Juan Carlos Aravena ◽  
Ricardo Villalba ◽  
Alexia Wolodarsky-Franke ◽  
Brian Luckman ◽  
...  
Keyword(s):  
Tree Ring ◽  
Radial Growth ◽  
Summer Precipitation ◽  
Central Andes ◽  
Early Summer ◽  
Late Spring ◽  
Tree Line ◽  
Nothofagus Pumilio ◽  
Precipitation Reconstruction ◽  
Climate Signal

Nothofagus pumilio (Poepp et Endl.) Krasser, is a deciduous tree species that grows in Chile and adjacent Argentina between 36 and 56°S, often forming the Andean tree line. This paper presents the first eight tree-ring chronologies from N. pumilio at its northern range limit in the central Andes of Chile (36–39°S) and the first precipitation reconstruction for this region. Samples were taken from upper tree-line stands (1500–1700 m elevation) in three study areas: Vilches, Laguna del Laja, and Conguillío. Results indicate that, at the northern sites (Vilches and Laguna del Laja), the tree-ring growth of N. pumilio is positively correlated with late-spring and early summer precipitation and that higher temperatures reduce radial growth, probably because of an increase in evapotranspiration and decrease in water availability. At the southern Conguillío study area, radial growth was negatively correlated with late-spring and early summer precipitation. The presence of volcanic activity in this latter study area, which might have masked the climate signal, did not seem to have a significant influence on radial growth. A reconstruction of November–December (summer) precipitation for the period 1837–1996 from N. pumilio tree-ring chronologies accounted for 37% of instrumentally recorded precipitation variance. This is the first precipitation reconstruction from N. pumilio chronologies. Only temperature and snow cover have previously been reconstructed using this species. The reconstruction indicates that the driest and wettest 25-year periods within the past 160 years are 1890–1914 and 1917–1941, respectively.

Relationships between wood anatomical traits and climate conditions at three beech forest sites in Slovenia

2021 ◽  
Author(s):  
Domen Arnič ◽  
Jožica Gričar ◽  
Jernej Jevšenak ◽  
Gregor Božič ◽  
Georg von Arx ◽  
...  
Keyword(s):  
Tree Ring ◽  
Tree Rings ◽  
Ring Width ◽  
Summer Precipitation ◽  
Beech Forest ◽  
Vessel Density ◽  
Climate Conditions ◽  
Vessel Area ◽  
Temperature And Precipitation ◽  
Forest Sites

<p>It is uncertain how European beech (Fagus sylvatica L.) will perform under climate change. Several dendroclimatological studies suggest that increasing temperature will positively affect radial increments at sites optimal for its growth. However, it is not entirely clear how changing growth conditions will affect wood anatomy and thus wood properties. The aim of this study was therefore to analyse the relationships between climate conditions (temperature and precipitation) and wood anatomical traits in beech trees growing at optimal beech forest sites in Slovenia. Three forest sites representing the main Slovenian beech provenances were selected (Idrija, Javorniki, and Mašun). At each site, 16 increment cores were collected in 2016 and subsequently prepared for observation under the light microscope. Image analysis software (Image Pro-Plus and Roxas) were used for quantitative wood anatomy. Mean vessel area, vessel density, and relative conductive area were analysed in tree rings between 1960-2016. Furthermore, tree rings were divided into four quarters to assess the intra-annual variability in vessel features also in relation to weather conditions. The preliminary results indicated that there was a significant difference in tree-ring widths as well as in vessel features among the selected forest sites. Idrija, the late flushing provenance, had the narrowest tree rings, the highest vessel density and relative conductive area, and smallest mean vessel area. The other two sites had a similar mean vessel area, while the widest tree-ring width and the smallest vessel density and relative conductive area were observed at Mašun (the mid-flushing provenance). The response of tree-ring width and vessel features to changing climate conditions differed among sites/provenance. Tree-ring widths at Idrija and Javornik were positively affected by late winter temperature, while tree-ring widths at Mašun were mostly affected by summer precipitation. In the case of vessel features, the highest correlations with climate data were observed in the fourth quarter of the rings with late summer temperature and precipitation. In conclusion, early spring temperatures and summer precipitation proved to be the most important climatic factors affecting beech growth and vessel features.</p>

scholarly journals Scots Pine (pinus sylvestris L.) on Shingle Fields: A Dendrochronologic Reconstruction of Early Summer Precipitation in Mideast Sweden

2009 ◽  
Vol 22 (17) ◽  
pp. 4710-4722 ◽  
Author(s):  
Karin Jönsson ◽  
Christer Nilsson
Keyword(s):  
Pinus Sylvestris ◽  
Tree Ring ◽  
Scots Pine ◽  
Principal Component ◽  
Summer Precipitation ◽  
Early Summer ◽  
Climate Data ◽  
Spring Precipitation ◽  
Dead Trees ◽  
Pine Trees

Abstract Scots pine (Pinus sylvestris L.) trees growing on shingle fields offer a unique possibility to reconstruct precipitation and study climate variability in the fairly humid eastern part of central Sweden. Tree-ring characteristics were compared with monthly (1890–2001) and daily (1961–2001) climate data from an adjacent meteorological station. Chronologies for latewood (LW), earlywood (EW), and tree-ring widths (RW) were constructed from 73 living and dead trees. Correlation analyses show that tree growth is most sensitive to early summer precipitation. EW shows the strongest correlation with precipitation in May and June while LW is best correlated with June and July precipitation. A reconstruction model for May–June precipitation was calculated using principal component analysis (PCA) regression (regular regression) including EW, LW, and RW for present and previous years. The model explained 46% of the variation in May–June precipitation and allowed a reconstruction back to 1560. Information about wet and dry years was collected from historical documents and was used to validate the result. Periods with precipitation above and below the mean show agreement with previous reconstructions of spring precipitation from tree rings in Finland and of spring floods from estuary sediments in the region. Analyses of correlations between meteorological stations and reconstructed precipitation show that the model is valid for the coastal part of central Sweden. The authors conclude that Scots pine trees on shingle fields are well suited for precipitation reconstruction, and the separate analyses of LW and EW improve the reconstruction.

scholarly journals White pine and Scots pine tree-ring chronologies as indicators of climate-related non-native and native tree growth patterns in Estonia

2020 ◽  
Vol 26 (2) ◽  
Author(s):  
Alar Läänelaid ◽  
Samuli Helama
Keyword(s):  
Tree Ring ◽  
Scots Pine ◽  
Pinus Strobus ◽  
Summer Precipitation ◽  
Growth Patterns ◽  
Late Winter ◽  
White Pine ◽  
Growth Anomaly ◽  
Pine Tree ◽  
Negative Growth

Three tree-ring chronologies of white pine (Pinus strobus), a species which are non-native to Europe, were constructed for Suuremõisa, Jädivere and Järvselja sites in Estonia. These chronologies were related to instrumental climate records and Scots pine (P. sylvestris) chronologies from nearby sites. Growth rates of P. strobus exceeded those of P. sylvestris. The chronologies of the non-native and native pine species relatively well correlated with each other. Moreover, tree-ring growth of both species correlated positively with late-winter and spring (February–May) temperatures and negatively with spring (April) precipitation. While P. strobus growth was positively associated with summer precipitation, the growth of P. sylvestris remained positively related to the growing season temperatures. Both species exhibited a negative growth anomaly from 1939 to 1942.   Keywords: Pinus strobus, Pinus sylvestris, dendroclimatology, Estonia

scholarly journals Dendroclimatological Potential of Drought-Sensitive tree Stands in Southern Tibet for the Reconstruction of Monsoonal Activity

IAWA Journal ◽  
1999 ◽  
Vol 20 (3) ◽  
pp. 325-338 ◽  
Author(s):  
Achim Bräuning
Keyword(s):  
Tree Ring ◽  
Asian Summer Monsoon ◽  
Rainfall Variability ◽  
Ring Width ◽  
Summer Precipitation ◽  
Late Summer ◽  
Southern Tibet ◽  
Pinus Densata ◽  
Growth Bands ◽  
Dry Conditions

Southem Tibet is influenced by the Asian summer monsoon which causes 70-80% of the annual precipitation to fall between June and August, showing a steep gradient from east to west. Teleconnections between the tree-ring chronologies of a sampling network have demonstrated a distinct dendroecological region in the catchment area of the Yarlung Tsangpo river, where tree growth is mainly limited by summer precipitation. Ring width at these sites is strongly correlated to late summer (August to October) precipitation of the year prior to growth, indicating that the trees bear a high potential for the reconstruction of the rainfall variability at the northwestem fringe of the monsoonal regime. Light rings and other wood anatomical features like intra-annual growth bands can be observed in the westernmost stands of Pinus densata. If these growth bands occur in the earlywood of the tree ring, they can be explained by cold events during spring; ifthey are located in the transition zone between earlywood and latewood, they are caused by dry conditions during May and especially June, which points to a delayed arrival of the moist monsoonal air masses in southem Tibet in the corresponding years.

Early summer precipitation in the lower Yangtze River basin for AD 1845–2011 based on tree-ring cellulose oxygen isotopes

2018 ◽  
Vol 52 (3-4) ◽  
pp. 1583-1594 ◽  
Author(s):  
Chenxi Xu ◽  
Jiangfeng Shi ◽  
Yesi Zhao ◽  
Takeshi Nakatsuka ◽  
Masaki Sano ◽  
...  
Keyword(s):  
River Basin ◽  
Tree Ring ◽  
Oxygen Isotopes ◽  
Yangtze River ◽  
Yangtze River Basin ◽  
Summer Precipitation ◽  
Early Summer ◽  
Lower Yangtze ◽  
Tree Ring Cellulose

scholarly journals Methane exchange at the peatland forest floor – automatic chamber system exposes the dynamics of small fluxes

2017 ◽  
Vol 14 (7) ◽  
pp. 1947-1967 ◽  
Author(s):  
Mika Korkiakoski ◽  
Juha-Pekka Tuovinen ◽  
Mika Aurela ◽  
Markku Koskinen ◽  
Kari Minkkinen ◽  
...  
Keyword(s):  
Linear Regression ◽  
Forest Floor ◽  
Early Summer ◽  
Late Winter ◽  
Exponential Regression ◽  
Biological Phenomena ◽  
Moss Layer ◽  
Dry Conditions ◽  
Ch4 Uptake ◽  
Heavy Rainfall Events

Abstract. We measured methane (CH4) exchange rates with automatic chambers at the forest floor of a nutrient-rich drained peatland in 2011–2013. The fen, located in southern Finland, was drained for forestry in 1969 and the tree stand is now a mixture of Scots pine, Norway spruce, and pubescent birch. Our measurement system consisted of six transparent chambers and stainless steel frames, positioned on a number of different field and moss layer compositions. Gas concentrations were measured with an online cavity ring-down spectroscopy gas analyzer. Fluxes were calculated with both linear and exponential regression. The use of linear regression resulted in systematically smaller CH4 fluxes by 10–45 % as compared to exponential regression. However, the use of exponential regression with small fluxes ( <  2.5 µg CH4 m−2 h−1) typically resulted in anomalously large absolute fluxes and high hour-to-hour deviations. Therefore, we recommend that fluxes are initially calculated with linear regression to determine the threshold for low fluxes and that higher fluxes are then recalculated using exponential regression. The exponential flux was clearly affected by the length of the fitting period when this period was  <  190 s, but stabilized with longer periods. Thus, we also recommend the use of a fitting period of several minutes to stabilize the results and decrease the flux detection limit. There were clear seasonal dynamics in the CH4 flux: the forest floor acted as a CH4 sink particularly from early summer until the end of the year, while in late winter the flux was very small and fluctuated around zero. However, the magnitude of fluxes was relatively small throughout the year, ranging mainly from −130 to +100 µg CH4 m−2 h−1. CH4 emission peaks were observed occasionally, mostly in summer during heavy rainfall events. Diurnal variation, showing a lower CH4 uptake rate during the daytime, was observed in all of the chambers, mainly in the summer and late spring, particularly in dry conditions. It was attributed more to changes in wind speed than air or soil temperature, which suggest that physical rather than biological phenomena are responsible for the observed variation. The annual net CH4 exchange varied from −104 ± 30 to −505 ± 39 mg CH4 m−2 yr−1 among the six chambers, with an average of −219 mg CH4 m−2 yr−1 over the 2-year measurement period.

Sign in / Sign up

Export Citation Format

Share Document