scholarly journals Indication of environmental changes in mountain catchments by dendroclimatology

2018 ◽  
Vol 13 (No. 4) ◽  
pp. 208-217 ◽  
Author(s):  
Vrtiška Jiří ◽  
Křeček Josef ◽  
Tognetti Roberto

In the Czech Republic, mountain watersheds are mostly forested with dominant Norway spruce (Picea abies) plantations. The aim of this paper is to analyse changes in radial growth and xylem anatomy of Norway spruce trees in the upper plain of the Jizera Mountains, related to changes in climate (air temperature, precipitation), air pollution and acid atmospheric deposition. Data of two neighbouring climate stations were used to detect trends in air temperatures and precipitation. At elevations of 745–1060 m a.s.l., the ring-width growth was significantly affected by mean annual temperature, while impacts of elevation and precipitation were not significant. In the period 1975–1995, the detected drop in tree radial growth (ca 60% of the normal period, prior to the peak of acid atmospheric deposition) corresponded to the increase in atmospheric SO<sub>2</sub> concentrations and acid atmospheric deposition. The number of cells in tree rings decreased by ca 30–40% in comparison with the normal period, but the mean size of cells did not change significantly. In the last 20 years, increasing radial growth has been detected simultaneously with rising air temperature, and density of cells decreased by 30% in early wood, and by 10% in late wood, increasing the total number of cells in tree rings by ca 10% in comparison with the normal period. Integrated effects of climate and non-climate variables on the variation of tree radial growth in the Jizera Mountains reflected the legacy of acid atmospheric deposition in the forest ecosystem.

2016 ◽  
Vol 65 (1) ◽  
pp. 43-56 ◽  
Author(s):  
Aysan Badraghi ◽  
Radek Pokorný ◽  
Kateřina Novosadová ◽  
Justina Pietras ◽  
Michal V. Marek

Abstract This investigation examined the effects of two different carbon dioxide concentrations ([CO2]): Ambient (A, 385 μmol (CO2) mol−1) and elevated (E, A+385 μmol (CO2) mol−1)) on the tree-ring width and early to latewood proportion in Norway spruce for seven years (2006-2012). Further, to improve our understanding of the influence of climatic variables, we assessed the effects of precipitation and temperature. Our observations showed that spruce trees growing under elevated CO2 (EC) formed less early (p > 0.05) and latewood (p < 0.05) and hence smaller annual increments (p > 0.05) than trees in ambient CO2 (AC). Early to latewood proportion was nearly 73% and 75% in AC and EC, respectively. In both CO2 concentrations, the largest tree-rings and earlywood width was observed during 2009 and 2010, which is coincident with the highest precipitation in May (2010) and the highest air temperature in April (2009). Moreover, to determine the association between the latewood formation and air temperature during the second half of the growing season, and correlation between the earlywood formation and precipitation during the first half of the growing season we run Spearman’s correlation test, the determination coefficient values for latewood formation were r = 0.45 (AC) and r = 0.68 (EC), and for earlywood formation were r = 0.53 (AC) and r = 0.42 (EC), although coefficient values were not statistically significant (p > 0.05). Also, our study indicated that temperature had stonger influence than precipitation in EC, but in AC precipitation had the strongest effect on radial growth.


2012 ◽  
Vol 32 (6) ◽  
pp. 724-736 ◽  
Author(s):  
J. Pumpanen ◽  
J. Heinonsalo ◽  
T. Rasilo ◽  
J. Villemot ◽  
H. Ilvesniemi

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
F. Cervi ◽  
M. M. Nistor

In this study, monthly time series of precipitations and temperatures from 1024 controlled and homogeneous meteorological stations located in the Emilia-Romagna region (northern Italy) are processed in order to assess potential climate changes that occurred during the period 1961–2015. Normal period as baseline between 1961 and 1990 (1990s) and recent period between 1991 and 2015 (2010s) were adopted in this study to analyse the possible effect of climate change on water availability during long-term period. Based on monthly and annual temperature (TT), precipitation (PP), and potential (ET0), the actual evapotranspiration (AET0) and water availability (WA) were computed at high spatial resolution. Between the two analysed periods, during the 2010s, it was found an increase in the maximum mean annual temperature by 1.08°C while the maximum mean annual precipitation saw a slight decrease (from 2222 mm to 2086 mm). The precipitation decrease is more intense in the South and West sectors of area (8%) and mainly depends on negative changes taking place during the winter and the beginning of spring (from December to March). The maximum mean annual ET0 and AET0 reached values of 663 mm and 565 mm during the 1990s, while during the 2010s, the found values were 668 mm and 572 mm, respectively. Because of the decrease in precipitation and increase in the ET0 and AET0, the WA (the proportion of precipitation that is available at the soil surface for subsequent infiltration and runoff processes) shows a reduction (about 10–20%) in the whole region, with exception of the North-East part of the Emilia-Romagna region. The decrease in the mean annual water availability induces severe issues concerning the water resources management across the whole Emilia-Romagna region.


Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 817 ◽  
Author(s):  
Lingnan Zhang ◽  
Hui Li ◽  
Yilin Ran ◽  
Keyi Wang ◽  
Xiaomin Zeng ◽  
...  

Increasing evidence suggests that extreme droughts cause more frequent tree growth reduction. To understand the consequences of these droughts better, this study used tree-ring cores from nine sites to investigate how moisture and altitudinal gradients affect the radial growth of Picea crassifolia Kom., a common species in the Qilian Mountains in northwest China. The total annual precipitation and mean annual temperature in the eastern region were higher than those in the western region of the Qilian Mountains. The trees in the eastern region showed stronger resistance to drought than those in the west, as they had a smaller difference in radial growth between drought disturbance and pre-drought disturbance. At the same time, the trees in the east showed weaker ability to recover from drought, as they had a subtle difference in radial growth between post-drought disturbance and drought disturbance. Furthermore, the trees in the east also showed weaker relative resilience to drought, as they had a small difference in radial growth between post-drought and drought disturbance weighted by growth in pre-drought disturbance. For trees below 3000 m a.s.l., trees with high resistance capacity usually had low recovery capacity and low relative resilience capacity. Trees at higher altitudes also showed stronger resistance to drought and weaker ability to recover from drought after a drought event than those at lower altitudes in the middle of the Qilian Mountains. Trees at lower altitudes in the middle of the Qilian Mountains had more difficulties recovering from more severe and longer drought events. In the context of global warming, trees in the western region and at lower altitudes should be given special attention and protection in forest management to enhance their resistance to extreme droughts.


Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 840 ◽  
Author(s):  
Zeltiņš ◽  
Katrevičs ◽  
Gailis ◽  
Maaten ◽  
Desaine ◽  
...  

In Europe, numerous Norway spruce (Picea abies L. Karst.) provenance trials have been established and evaluated at a juvenile age. Still, information about the adaptation potential and long-term fitness of transferred seedlots in the Baltic Sea region is lacking. The aim of the study was to evaluate the adaptation capacity of provenances and assess the patterns of their long-term reaction to environmental transfer. We examined a 32-year-old provenance trial in the mild Baltic Sea coastal climate of Western Latvia. Significant differences in height and stem volume were observed among provenances. Growth superiority for certain local and Carpathian provenances was maintained over more than one-third of the rotation period. The best predictor of climate transfer functions was minimum temperature of the coldest month at the place of origin, explaining 28% variation in tree height. Populations from sites with more frost days and a colder mean annual temperature, minimum temperature, and lower annual heat-moisture index than the planting site were generally taller.


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