If Trees Could Talk - Dendrochemistry, a Promising Method for Understanding Pollution History
Abstract
Heavy metal pollution presents a significant environmental challenge in the Anthropocene era,
and understanding pollution history is crucial to address historical pollution and implementing
effective mitigation measures. This study stands among a few comprehensive dendrochemical
investigations that utilized an extensive dataset and energy dispersive X-ray fluorescence (EDXRF)
technique to reconstruct the contamination history of As, Cd, Cu, Ni, Pb, and Zn, with a
focus on Cu. Twenty-two samples from European aspen (Populus tremula) and 15 soil samples
were collected from an abandoned copper mine in Åtvidabergs municipality, with the aim to
evaluate dendrochemistry as a method to investigate contamination history.
Soil samples exhibit high variability in contamination levels and pH over short distances,
revealing a complex soil pollution picture and a poor correlation between heavy metal
concentration in soil and tree-ring concentration. Concurrently, significantly higher tree-ring
concentrations and variances are observed in the averaged dendrochemical profile and in
individual samples, in the following order: Cu > Ni > As > Zn > Pb > Cd . Correlations with
first difference and detrended data show a weak relationship with short-term climatic variations.
However, a collective signal of increased dendrochemical anomalies during climatic conditions
favoring high water flow is evident, suggesting dendrochemistry as a potential alternative for
the reconstruction of past hydrological variations. Dendrochemical methods and European
aspen demonstrates potential for recording environmental changes. Nevertheless, lower trace
element concentrations in samples from the mines compared to the unpolluted site highlight
limitations. For dendrochemistry to become a reliable tool for environmental investigations,
future research should refine approaches for grouping climatic variables, understand the effects
of different water sources on trace element uptake, and explore various plant parts to obtain a
more accurate picture of historical contamination events. It is also essential to examine the high
variability within the Populus genus.
Addressing these challenges will contribute to establishing dendrochemistry as a valuable tool
for understanding historical pollution events and their ecological impacts. Ultimately, this
research will shape future mitigation and restoration efforts for ecosystems impacted by
anthropogenic activities and pollution.
Degree
Student essay
Collections
View/ Open
Date
2023-08-17Author
Uusitalo, Jonatan
Series/Report no.
B1248
Language
eng