Assessing forest health via linking the geochemical properties of a soil profile with the biochemical parameters of vegetation

Abstract

The transfer of chemical elements/compounds within the soil-plant chain is a part of the biochemical cycling, and this system is controlled by biotic and abiotic factors which determine the final mobility and availability of chemical variables. Heavy metal contamination and low pH are stress factors that lead to changes in the contents of important foliage compounds, which can be used as nonspecific indicators of plant stress. In this study, Norway spruce forests in the Sokolov region, being a part of the ''Black Triangle,'' were selected to assess geochemical and biochemical interactions in the natural soil/plant system. The authors studied the relationship between soil and spruce needle contents of macronutrients and potentially toxic elements and tested whether the soil parameters and their vertical distribution within a soil profile (two organic and two mineral horizons) affect foliage biochemical parameters (contents of photosynthetic pigments, phenolic compounds and lignin). Factor analysis was used to identify underlying variables that explained the pattern of correlations within and between the biochemical and geochemical datasets. Aluminum (Al) and arsenic (As) were identified as toxic elements with high bio-availability for spruce trees, and both were taken up by trees and translocated to the foliage. The correlations between two toxic element contents in needles (Al and As) and the contents of soluble phenolic compounds and total carotenoid to chlorophyll ratio suggest that these latter two biochemical parameters, which both proved to be sensitive to the soil geochemical conditions, can serve as suitable non-specific stress markers.

Modelling Diverse Soil Attributes with Visible to Longwave Infrared Spectroscopy Using PLSR Employed by an Automatic Modelling Engine

“…It has been explained that pH, as well as Zn and As, show indirect spectral indications to iron oxides, organic matter and clay minerals ( Figure 5). This relationship was also described in [33] where multivariate statistics were employed on a chemical analysis characterizing diverse horizons within the soil profile in order to define a conceptual model for the chemical and biochemical processes taking place in the studied soil-tree system. On the other hand, the second group (BC, BS, Pb, Hg, and Cu) has a stronger relationship to phyllosilicate content together with organic component (C org ).…”

“…The soil was sampled from natural Norway spruce forest stands which surround the open-cast lignite mines in Sokolov, but have not been directly affected by the mining activities. However, the soil in all of the stands exhibits low pH [33].…”

Detection of Spatio-Temporal Changes of Norway Spruce Forest Stands in Ore Mountains Using Landsat Time Series and Airborne Hyperspectral Imagery

“…Worsening of tree physiological status is usually exhibited by an increase in the C a /C b ratio as chlorophyll-b is regarded to be more sensitive to vegetation stress than chlorophyll-a [57]. Similarly, stress conditions lead to an increase in the C x /C ab ratio [58][59][60].…”

Investigation of Spectral Variation of Pine Needles as an Indicator of Arsenic Content in Soils

“…Kopačková et al [61] analyzed the transfer of chemical elements (e.g., Cu, Zn, and As) in a soil-plant system, and found that the As content in the needle of spruce trees was highly correlated with the soil's As content. It is known that As has high bioavailability in herbaceous plants and coniferous trees [3,61,62]. This study confirmed the high correlation between As content in pine needles and soils.…”

“…Conifers have a high foliar phenolic ratio of 7.3%-12.3% to carbon content of trees [70]. Phenolic compounds are known as heterogeneous groups that protect against environmental stress conditions [61]. Lignin, a structural compound of polyphenolics nature, also plays an important role in litter composition and nutrient cycling in needles [71].…”