Comparison of three tree‐ring sampling methods for trace metal analysis

Abstract

Tree‐ring growth analysis can provide information about tree development for forest inventory, environmental assessment, atmospheric and soil monitoring. Metal concentrations in wood increment correlate with metal concentrations in the environment and can indicate local environmental contamination sources. One of the most important steps of tree analysis is tree‐ring sampling. To determine trace metal (TM) concentrations precisely in a separate ring, the possibility of random errors during wood sampling must be eliminated. This guides to choose a precise tree‐ring sampling method. This paper examines three tree‐ring sampling tools (common chisels, arched chisels and a plane) and compares TM concentrations (Mn, Zn, Ni, Cr, Cu, Pb,) in wood samples collected by each of the methods employed. Average values of metals in tree rings sampled with common chisels, arched chisels and plane were 17.0±0.16 mg/kg for Mn, 4.7±0.21 mg/kg for Zn, 0.49±0.20 mg/kg for Pb, 0.29±0.02 mg/kg for Cu, 0.21±0.02 mg/kg for Ni and 0.12±0.01 mg/kg for Cr and were in the range of typical concentrations in investigated region as well as for Pinus sylvestris L. The average values were calculated for the three methods used. Statistical analysis (Anderson–Darlin test, Kruskal–Wallis tests, median and percentage coefficient of variation) revealed no significant differences between metal concentrations determined in tree rings which were sampled using common chisels, arched chisels and planing. Various techniques – common chisels, arched chisels and plane – can be successfully used for tree‐ring sampling, however, an increment borer provides possibility of sampling a non‐felled tree.

Santrauka

Medienos metiniu rieviu analize suteikia informacijos apie medžio vystymasi, svarbios inventorizuojant miškus, vertinant aplinkos poveiki, atliekant aplinkos oro ir dirvožemio monitoringa. Sunkiuju metalu koncentracijos metinese rievese susijusios su metalu koncentracijomis aplinkoje ir gali nusakyti vietines aplinkos taršos lygi. Vienas iš svarbiu medienos analizes etapu yra metiniu rieviu eminiu emimas. Siekiant tiksliai nustatyti sunkiuju metalu koncentracija metineje rieveje svarbu išvengti atsitiktiniu paklaidu. Šiame darbe aptariami trys metiniu rieviu eminiu emimo metodai (iprastiniai kaltai, lenktieji kaltai ir obliavimas) ir lyginamos pagrindiniu sunkiuju metalu (Mn, Zn, Ni, Cu, Cr, Pb) koncentracijos eminiuose, paimtuose kiekvienu iš minetuju metodu. Vidutines sunkiuju metalu koncentracijos, nustatytos šiais metodais, sieke 17,0±0,16 mg/kg Mn, 4,7±0,21 mg/kg Zn, 0,49±0,20 mg/kg Pb, 0,29±0,02 mg/kg Cu, 0,21±0,02 mg/kg Ni ir 0,12±0,01 mg/kg Cr ir buvo panašios i koncentracijas, aptiktas Pinus sylvestris L. medienoje nagrinejamoje teritorijoje. Apskaičiuotos vidutines vertes. Atlikus statistine analize (Anderson ir Darlin testas, Kruskal ir Wallis testas, variacijos koeficientas) tebuvo tik nereikšmingas sunkiuju metalu koncentraciju metinese rievese skirtumas, eminius emus aptartais metodais. Ivairūs metodai – iprastiniai kaltai, lenktieji kaltai ir obliavimas – gali būti sekmingai taikomi metiniu rieviu eminiams imti, tačiau “amžiaus” gražtu eminius galima imti nenukertant medžio.

Keywords:

• trace metals
• chisel
• wood samples
• tree ring
• plane

Reikšminiai žodžiai:

• "amžiaus” gražtas
• kaltas
• medienos eminiai
• metine rieve
• obliavimas
• sunkieji metalai