Shellfish could supplant tree-ring climate data

Nature ◽  
2010 ◽  
Author(s):  
Richard A. Lovett
Keyword(s):  
Tree Ring ◽  
Climate Data

Linking tree rings, summer aridity, and regional fire data: an example from the boreal forests of the Komi Republic, East European Russia

2004 ◽  
Vol 34 (11) ◽  
pp. 2327-2339 ◽  
Author(s):  
Igor Drobyshev ◽  
Mats Niklasson
Keyword(s):  
Tree Ring ◽  
Boreal Forests ◽  
Fire Suppression ◽  
Siberian Larch ◽  
Komi Republic ◽  
Burned Area ◽  
Annual Number ◽  
Climate Data ◽  
Tree Ring Data ◽  
Fire Activity

To evaluate the potential use of tree-ring data as a proxy for fire activity at the scale of a large boreal region, we analyzed a set of regional tree-ring chronologies of Siberian larch (Larix sibirica L.), a spatially implicit annual fire record, and monthly climate data for the Komi Republic for the period 1950–1990. In most years, annually burned area was below 0.001% of the republic's forested area and reached up to 0.7% during fire-prone years. Principal components (PC) of summer aridity resolved 64.2% of the annual variation in the number of fires, 12.2% in the average fire size, and 59.2% in the annually burned area. In turn, tree-ring PCs explained 65.2% of variation in fire-related weather PCs. Dendrochronological reconstruction of the annual number of fires and of the log-transformed annually burned area predicted 27.0% and 40.1% of the high-frequency variance of these variables, respectively. Coefficient of efficiency, a measure of reconstruction usefulness, reached 0.081 (number of fires) and 0.315 (annual area burned), supporting the obtained index as a realistic proxy for regional fire activity. Decadal variation in coefficient of efficiency values suggested improved monitoring accuracy since 1960 and more effective fire suppression during the last studied decade (1980–1990).

Chronology development and climate response analysis of different New Zealand pink pine (Halocarpus biformis) tree-ring parameters

1998 ◽  
Vol 28 (4) ◽  
pp. 566-573 ◽  
Author(s):  
Limin Xiong ◽  
Naoki Okada ◽  
Takeshi Fujiwara ◽  
Sadaaki Ohta ◽  
Jonathan G Palmer
Keyword(s):  
New Zealand ◽  
Tree Ring ◽  
Ring Width ◽  
Response Analysis ◽  
Data Series ◽  
Climate Response ◽  
Climate Data ◽  
Local Climate ◽  
Latewood Density ◽  
Earlywood Width

Seven different tree-ring parameters (total ring width, earlywood width, latewood width, maximum latewood density, minimum earlywood density, average earlywood density, and average latewood density) were obtained from pink pine (Halocarpus biformis Hook.) at one chronology site in New Zealand (NZ). The chronologies were analyzed individually and then compared with each other. The relationships between the different tree-ring parameters and climate data (NZ average and local climate data) are also presented. There were more significant climate response functions in the NZ national average climate series than that of local climate data series. Earlywood-related parameters (earlywood width, minimum density, and average earlywood density) were more sensitive to climate than those of latewood. Temperature during the NZ growth season (November-March) was found to be the most strongly related to tree growth. This study demonstrates that the use of both ring width and ring density data can increase the climate information obtained from ring widths and should lead to improved paleoclimate reconstructions in New Zealand.

scholarly journals Tree growth and its climate signal along latitudinal and altitudinal gradients: comparison of tree rings between Finland and Tibetan Plateau

2017 ◽  
Author(s):  
Lixin Lyu ◽  
Susanne Suvanto ◽  
Pekka Nöjd ◽  
Helena M. Henttonen ◽  
Harri Mäkinen ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Tree Ring ◽  
Tree Growth ◽  
Latitudinal Gradient ◽  
Ring Width ◽  
Growing Season ◽  
Climate Variables ◽  
Climate Data ◽  
Altitudinal Gradients ◽  
Summer Temperatures

Abstract. Latitudinal and altitudinal gradients can be utilized to forecast the impacts of climate changes on forests. To improve the understanding of forest dynamics on these gradients, we tested two hypotheses: (1) the change in the tree growth-climate relationship is similar along both latitudinal and altitudinal gradients, and (2) the time periods during which climate affects growth the most occur later towards higher latitudes and altitudes. We used tree-ring data from a latitudinal gradient in Finland and two altitudinal gradients on the Tibetan Plateau. We analysed the latitudinal and altitudinal growth patterns in tree-rings and investigated the growth-climate relationships of trees by correlating ring-width index chronologies with climate variables calculated with flexible time-windows, using daily-resolution climate data. The high latitude and altitude plots showed higher correlations between the tree-ring chronologies and growing season temperature. However, the effects of winter temperature showed differing patterns for the gradients. The timing of highest correlation with summer temperatures in southern sites was approximately one month ahead of the northern sites in the latitudinal gradient. In one out of the two altitudinal gradients the timing of strongest negative correlation with summer temperatures at low altitude sites was ahead of the treeline sites, possibly due to differences in moisture limitation. Mean values and the standard deviation of tree-ring width was found to increase with increasing mean summer temperatures on both types of gradients. Our results showed similarities of tree growth responses to growing season temperature between latitudinal and altitudinal gradients. However, differences in climate-growth relationships were also found between the gradients, due to differences in other factors, such as moisture conditions. Changes in the timing of the most critical climate variables demonstrated the need to use daily resolution climate data in studies on environmental gradients.

scholarly journals Oak decline in a southern Finnish forest as affected by a drought sequence

2014 ◽  
Vol 41 (1) ◽  
pp. 92-103 ◽  
Author(s):  
Kristina Sohar ◽  
Samuli Helama ◽  
Alar Läänelaid ◽  
Juha Raisio ◽  
Heikki Tuomenvirta
Keyword(s):  
Tree Ring ◽  
Time Lag ◽  
Ring Width ◽  
Summer Drought ◽  
Radial Increment ◽  
Pedunculate Oak ◽  
Climate Data ◽  
Tree Ring Data ◽  
The Dead ◽  
Old Trees

Abstract We investigated the decline of a pedunculate oak (Quercus robur L.) forest growing on shallow soil at the northern distributional limit of the species in southern Finland, using the dendroclimatic approach. About 200-year-old trees in three vigour classes — healthy, declining and dead — were sampled in 2008. Annual tree-ring, earlywood and latewood widths were measured and chronologies were established. The tree-ring data were correlated with monthly and seasonal climate data. Radial increment of oaks was positively related to the June and July precipitations. This was expressed especially in total ring width and latewood width, whereas the earlywood was more influenced by the warmer winter and spring. Furthermore, the correlation between the current year earlywood width and the preceding year latewood width was higher than between the earlywood and latewood of the same year. The analyses showed that the dead oaks and part of the declining oaks had ceased growing during 2005–2007 after a decadelong summer drought series. This indicates a time lag in the oak dieback. The radial growth of the declining and the dead oaks had dropped already since the 1990s, while the healthy oaks had better longterm growth and higher adaptive capacity to climate variation.

scholarly journals Contribution of tree-ring analysis to the study of droughts in northwestern France (XIX–XXth century)

2008 ◽  
Vol 4 (1) ◽  
pp. 249-270 ◽  
Author(s):  
O. Planchon ◽  
V. Dubreuil ◽  
V. Bernard ◽  
S. Blain
Keyword(s):  
Spatial Distribution ◽  
Tree Ring ◽  
Growth Index ◽  
Summer Drought ◽  
Climate Data ◽  
Vegetative Period ◽  
Xxth Century ◽  
Tree Ring Analysis ◽  
Ring Analysis

Abstract. A tree-ring analysis based on oak samples in the North-West of France showed the effects of droughts periods on the growth index, during the late XIXth and XXth century. Four types of droughts were identified using the results of the tree-ring analysis and the available climate data. The "type 1" was subjected to a continuous and intense drought during all the vegetative period (spring and summer), the "type 2" was subjected to a summer drought succeeding no precipitation deficit in spring, the "type 3" was subjected to a remarkable winter drought and during the years of the "type 4", precipitation deficits were recorded for several but not successive months, over an heterogeneous spatial distribution. The long, intense and countinuous droughts clearly showed a spatial structuring effect on the growth index, especially when the two successive vegetative seasons (spring and summer) recorded strong precipitation deficits combined with shrivellings. These extreme cases involved the lowest growth index over most of the studied area, with some variations due to the altitude and exposure effects on the local-scale spatial distribution of the hydrological stress. The hydrological balance for the station of Rennes (Brittany) confirmed these results in accordance with the intensity and/or duration of drought periods: the most intense droughts of the "type 1" were especially pointed out. A climatic interpretation of growth index data and maps could so be possible over northwestern France with an application to the medieval times and perhaps to other periods, but the cause of the different drought patterns must be more precisely studied during the contemporary period (late XIXth century and all the XXth century).

scholarly journals Tree growth and its climate signal along latitudinal and altitudinal gradients: comparison of tree rings between Finland and the Tibetan Plateau

2017 ◽  
Vol 14 (12) ◽  
pp. 3083-3095 ◽  
Author(s):  
Lixin Lyu ◽  
Susanne Suvanto ◽  
Pekka Nöjd ◽  
Helena M. Henttonen ◽  
Harri Mäkinen ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Tree Ring ◽  
Tree Growth ◽  
Latitudinal Gradient ◽  
Ring Width ◽  
Growing Season ◽  
The Tibetan Plateau ◽  
Climate Variables ◽  
Climate Data ◽  
Altitudinal Gradients

Abstract. Latitudinal and altitudinal gradients can be utilized to forecast the impact of climate change on forests. To improve the understanding of how these gradients impact forest dynamics, we tested two hypotheses: (1) the change of the tree growth–climate relationship is similar along both latitudinal and altitudinal gradients, and (2) the time periods during which climate affects growth the most occur later towards higher latitudes and altitudes. To address this, we utilized tree-ring data from a latitudinal gradient in Finland and from two altitudinal gradients on the Tibetan Plateau. We analysed the latitudinal and altitudinal growth patterns in tree rings and investigated the growth–climate relationship of trees by correlating ring-width index chronologies with climate variables, calculating with flexible time windows, and using daily-resolution climate data. High latitude and altitude plots showed higher correlations between tree-ring chronologies and growing season temperature. However, the effects of winter temperature showed contrasting patterns for the gradients. The timing of the highest correlation with temperatures during the growing season at southern sites was approximately 1 month ahead of that at northern sites in the latitudinal gradient. In one out of two altitudinal gradients, the timing for the strongest negative correlation with temperature at low-altitude sites was ahead of treeline sites during the growing season, possibly due to differences in moisture limitation. Mean values and the standard deviation of tree-ring width increased with increasing mean July temperatures on both types of gradients. Our results showed similarities of tree growth responses to increasing seasonal temperature between latitudinal and altitudinal gradients. However, differences in climate–growth relationships were also found between gradients due to differences in other factors such as moisture conditions. Changes in the timing of the most critical climate variables demonstrated the necessity for the use of daily-resolution climate data in environmental gradient studies.

scholarly journals Circumferential and Longitudinal δ13C Variability in a Larix decidua Trunk from the Swiss Alps

Forests ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 117 ◽  
Author(s):  
Jan Esper ◽  
Dana F.C. Riechelmann ◽  
Steffen Holzkämper
Keyword(s):  
Tree Ring ◽  
Regional Climate ◽  
Tree Height ◽  
Vertical Gradient ◽  
Larix Decidua ◽  
Swiss Alps ◽  
Systematic Change ◽  
Climate Data ◽  
Δ13c Values ◽  
The Difference

Tree-ring stable isotopes are insightful proxies providing information on pre-instrumental climate fluctuations, yet the variability of these data within a tree trunk has not been fully explored. Here, we analyze longitudinal and circumferential changes in tree-ring δ13C values from 1991–2010, considering seven height levels from 1 to 13 m above ground and six sampling directions (radii) separated by 60° around the stem. The disk samples were taken from a 360-year old European larch (Larix decidua Mill.) that grew at 1675 m above sea level in the Simplon Valley, Switzerland. Results show that the circumferential δ13C variability, defined as the difference between the minimum and maximum isotope values within a single ring at a certain height, ranges from 0.5 to 2.8‰. These differences appear substantial as they match the range of year-to-year variations retained in long tree-ring δ13C time series used for climate reconstruction. The assessment of longitudinal variability demonstrated a systematic change of ~0.1‰ m−1 towards isotopically heavier (less negative) δ13C values with increasing tree height, likely reflecting a vertical gradient towards isotopically heavier needle tissue due to changing microclimatic conditions and CO2 stratification within the canopy. Calibration against regional climate data indicates no substantial signal changes in δ13C values within the trunk. We conclude that the longitudinal isotope gradient adds uncertainty to long δ13C chronologies derived from subfossil material of unknown (and changing) sampling heights. The large circumferential variability recorded in the sub-alpine larch suggests that more than two cores are needed to analyze absolute δ13C values representative for each tree.

Climatic reconstruction from tree rings at Banff

1988 ◽  
Vol 18 (7) ◽  
pp. 888-900 ◽  
Author(s):  
E. O. Robertson ◽  
L. A. Jozsa
Keyword(s):  
Tree Ring ◽  
Transfer Functions ◽  
Principal Component ◽  
Regression Equations ◽  
Climate Variables ◽  
Climate Data ◽  
Data Set ◽  
Tree Ring Data ◽  
Variable Data ◽  
Component Scores

This study describes new techniques of tree-ring data preparation and data analysis for deriving proxy climate data from senescent Douglas-fir (Pseudotsugamenziesii var. glauca (Beissn.) Franco) trees from the Canadian Rockies, near Banff, Alberta. Fifteen annual tree-ring variables were measured by X-ray densitometry for 429 years (1550–1978) for 12 increment cores. Ring variable data were reduced to standard indexes using a 99-year normally weighted digital filter. Missing ring values were estimated using correlation with younger and more vigorous specimens, and each ring variable data set (12 cores × 429 years) was reduced to its first and second principal component score, to be used in the development of response and transfer functions. Factor analysis identified six subsets of ring variable principal component scores. The best multiple regression equations for transferring tree-ring variable principal components into reconstruction of climate were identified by screening all possible combinations of principal component scores between factor groups. Annual climate variables, such as total precipitation, did not transfer as successfully as did the shorter-term climate variables like June–July precipitation (R2 = 0.36 compared with 0.51). Verified transfer functions were developed for five climate variables which can now be reconstructed to 1550 a.d. (429 years).

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