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Variations in Environmental Signals in Tree-Ring Indices in Trees with Different Growth Potential.

Hafner P, Gričar J, Skudnik M, Levanič T - PLoS ONE (2015)

Bottom Line: We discovered that W oaks grew significantly better over the whole analysed period.The difference between D and W oaks was significant in all analysed variables with the exception of stable carbon isotope discrimination in latewood.Our analysis confirmed our assumptions that separate EW and LW analysis of widths and carbon isotope discrimination provides complementary information in Q. robur dendroecology.

View Article: PubMed Central - PubMed

Affiliation: Department of Forest Yield and Silviculture, Slovenian Forestry Institute, Ljubljana, Slovenia.

ABSTRACT
We analysed two groups of Quercus robur trees, growing at nearby plots with different micro-location condition (W-wet and D-dry) in the floodplain Krakovo forest, Slovenia. In the study we compared the growth response of two different tree groups to environmental variables, the potential signal stored in earlywood (EW) structure and the potential difference of the information stored in carbon isotope discrimination of EW and latewood (LW). For that purpose EW and LW widths and carbon isotope discrimination for the period 1970-2008 AD were measured. EW and LW widths were measured on stained microscopic slides and chronologies were standardised using the ARSTAN program. α-cellulose was extracted from pooled EW and LW samples and homogenized samples were further analysed using an elemental analyser and IRMS. We discovered that W oaks grew significantly better over the whole analysed period. The difference between D and W oaks was significant in all analysed variables with the exception of stable carbon isotope discrimination in latewood. In W oaks, latewood widths correlated with summer (June to August) climatic variables, while carbon isotope discrimination was more connected to River Krka flow during the summer. EW discrimination correlated with summer and autumn River Krka flow of the previous year, while latewood discrimination correlated with flow during the current year. In the case of D oaks, the environmental signal appears to be vague, probably due to less favourable growth conditions resulting in markedly reduced increments. Our study revealed important differences in responses to environmental factors between the two oak groups of different physiological conditions that are preconditioned by environmental stress. Environmental information stored in tree-ring features may vary, even within the same forest stand, and largely depends on the micro-environment. Our analysis confirmed our assumptions that separate EW and LW analysis of widths and carbon isotope discrimination provides complementary information in Q. robur dendroecology.

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Related in: MedlinePlus

Correlation between analysed tree-ring parameters and meteorological variables.Correlation with A temperature, B precipitation, C relative humidity and D sunshine on a seasonal time scale (from previous to current summer). The dashed line denotes statistically significant values at a level of 95%. EW-Δ–earlywood discrimination, LW-Δ–latewood discrimination, EW-W—earlywood width, LW-W—latewood width, SUM—summer (from June to August), AUT—autumn (from September to November), WIN—winter (from December to February), SPR—spring (from March to May). Small letters denote the previous year.
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pone.0143918.g006: Correlation between analysed tree-ring parameters and meteorological variables.Correlation with A temperature, B precipitation, C relative humidity and D sunshine on a seasonal time scale (from previous to current summer). The dashed line denotes statistically significant values at a level of 95%. EW-Δ–earlywood discrimination, LW-Δ–latewood discrimination, EW-W—earlywood width, LW-W—latewood width, SUM—summer (from June to August), AUT—autumn (from September to November), WIN—winter (from December to February), SPR—spring (from March to May). Small letters denote the previous year.

Mentions: Temperature did not affect EW and LW features of D oaks (Fig 6A). EW-W of D oaks responded negatively to a wet (Fig 6B) and humid (Fig 6C) summer of the previous year, while a sunny summer (Fig 6D) and wet autumn (Fig 6B) of the previous year promoted its width. With EW-Δ of D oaks, current summer is negatively correlated with summer sunshine duration (Fig 6D).


Variations in Environmental Signals in Tree-Ring Indices in Trees with Different Growth Potential.

Hafner P, Gričar J, Skudnik M, Levanič T - PLoS ONE (2015)

Correlation between analysed tree-ring parameters and meteorological variables.Correlation with A temperature, B precipitation, C relative humidity and D sunshine on a seasonal time scale (from previous to current summer). The dashed line denotes statistically significant values at a level of 95%. EW-Δ–earlywood discrimination, LW-Δ–latewood discrimination, EW-W—earlywood width, LW-W—latewood width, SUM—summer (from June to August), AUT—autumn (from September to November), WIN—winter (from December to February), SPR—spring (from March to May). Small letters denote the previous year.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4664244&req=5

pone.0143918.g006: Correlation between analysed tree-ring parameters and meteorological variables.Correlation with A temperature, B precipitation, C relative humidity and D sunshine on a seasonal time scale (from previous to current summer). The dashed line denotes statistically significant values at a level of 95%. EW-Δ–earlywood discrimination, LW-Δ–latewood discrimination, EW-W—earlywood width, LW-W—latewood width, SUM—summer (from June to August), AUT—autumn (from September to November), WIN—winter (from December to February), SPR—spring (from March to May). Small letters denote the previous year.
Mentions: Temperature did not affect EW and LW features of D oaks (Fig 6A). EW-W of D oaks responded negatively to a wet (Fig 6B) and humid (Fig 6C) summer of the previous year, while a sunny summer (Fig 6D) and wet autumn (Fig 6B) of the previous year promoted its width. With EW-Δ of D oaks, current summer is negatively correlated with summer sunshine duration (Fig 6D).

Bottom Line: We discovered that W oaks grew significantly better over the whole analysed period.The difference between D and W oaks was significant in all analysed variables with the exception of stable carbon isotope discrimination in latewood.Our analysis confirmed our assumptions that separate EW and LW analysis of widths and carbon isotope discrimination provides complementary information in Q. robur dendroecology.

View Article: PubMed Central - PubMed

Affiliation: Department of Forest Yield and Silviculture, Slovenian Forestry Institute, Ljubljana, Slovenia.

ABSTRACT
We analysed two groups of Quercus robur trees, growing at nearby plots with different micro-location condition (W-wet and D-dry) in the floodplain Krakovo forest, Slovenia. In the study we compared the growth response of two different tree groups to environmental variables, the potential signal stored in earlywood (EW) structure and the potential difference of the information stored in carbon isotope discrimination of EW and latewood (LW). For that purpose EW and LW widths and carbon isotope discrimination for the period 1970-2008 AD were measured. EW and LW widths were measured on stained microscopic slides and chronologies were standardised using the ARSTAN program. α-cellulose was extracted from pooled EW and LW samples and homogenized samples were further analysed using an elemental analyser and IRMS. We discovered that W oaks grew significantly better over the whole analysed period. The difference between D and W oaks was significant in all analysed variables with the exception of stable carbon isotope discrimination in latewood. In W oaks, latewood widths correlated with summer (June to August) climatic variables, while carbon isotope discrimination was more connected to River Krka flow during the summer. EW discrimination correlated with summer and autumn River Krka flow of the previous year, while latewood discrimination correlated with flow during the current year. In the case of D oaks, the environmental signal appears to be vague, probably due to less favourable growth conditions resulting in markedly reduced increments. Our study revealed important differences in responses to environmental factors between the two oak groups of different physiological conditions that are preconditioned by environmental stress. Environmental information stored in tree-ring features may vary, even within the same forest stand, and largely depends on the micro-environment. Our analysis confirmed our assumptions that separate EW and LW analysis of widths and carbon isotope discrimination provides complementary information in Q. robur dendroecology.

Show MeSH
Related in: MedlinePlus