Timber isoscapes. A case study in a mountain area in the Italian Alps

Abstract

BackgroundLocal timber is still one of the main sources of work and income for mountain communities. However, illegal logging is a major cause of deforestation in many countries and has significant impacts on local communities and biodiversity. Techniques for tracing timber would provide a useful tool to protect local timber industries and contribute to the fight against illegal logging. Although considerable progress has been made in food traceability, timber provenance is still a somewhat neglected research area. Stable isotope ratios in plants are known to reflect geographical variations. This study reports accurate spatial distribution of δ18O and δ2H in timber from north-eastern Italy (Trentino) in order to trace geographical origin.Methodology and principal findingsWe tested the accuracy of four kriging methods using an annual resolution of δ18O and δ2H measured in Picea abies. Pearson’s correlation coefficients revealed altitude to be the most appropriate covariate for the cokriging model, which has ultimately proved to be the best method due to its low estimation error.ConclusionsWe present regional maps of interpolated δ18O and δ2H in Picea abies wood together with the 95% confidence intervals. The strong spatial structure of the data demonstrates the potential of multivariate spatial interpolation, even in a highly heterogeneous area such as the Alps. We believe that this geospatial approach can be successfully applied on a wider scale in order to combat illegal logging.

A geographical traceability system for Merbau (Intsia palembanica Miq.), an important timber species from peninsular Malaysia

“…The identity of timber species can be verified on the basis of wood anatomy [10], metabolic profiles [11], near-infrared spectroscopy [12] and DNA barcoding [13]. Geographic origin along the timber supply chain can be verified by tree rings [14], stable isotopes [15] and population structure [13,16]. All the innovative tools used for the species identification and geographic tracing of wood to verify trade claims have been summarized and are updated regularly on the Global Timber Tracking Network (https:// globaltimbertrackingnetwork.org/), which is an interactive and continuously growing online platform for sharing information and supporting researchers, forests and the timber industry.…”

A δ2H Isoscape of blackberry as an example application for determining the geographic origins of plant materials in New Zealand

“…Another approach, where sufficient data are available, is to directly model the changing patterns in the target biological material. There are a number of modelling approaches reported in the literature that could be applied to do this, including empirical comparisons using linear regression [8], geostatistical modelling of the semivariance [28] or mechanistic modelling [24]. For comparison purposes, in this investigation, the measured δ 2 H values for the blackberry leaves were empirically modelled by multiple linear regression (Model 3).…”

“…The utility of hydrogen isotope ratios as geographic origin indicators has been shown in numerous applications, including archaeology [26], food authentication [27] and forensics [24,28–31]. Booth et al [29] utilised δ 2 H as one of several stable isotope indicators for the geographic origins of marijuana grown within and from outside of Alaska.…”

WorldForestID: Addressing the need for standardized wood reference collections to support authentication analysis technologies; a way forward for checking the origin and identity of traded timber

“…Since the turn of the century, a growing number of laboratories around the world have adopted the technology as a means of verifying the origin of food and drink (Boner & Förstel, 2004; Heaton et al., 2008; Kelly et al., 2007; Kelly & Rhodes, 2002; Li et al., 2014; Pilgrim et al., 2010). The same principles used to authenticate food were later applied to timber provenance research (Boner et al., 2007; Gori et al., 2013, 2018; Horacek et al., 2009; Kagawa et al., 2008; Kagawa & Leavitt, 2010; Keppler et al., 2007; Rees, 2015). Stable isotope signatures have also been used to assess how environmental and physiological effects define the isotopic composition of C, O, and N in the wood of tropical trees (Sleen et al., 2017).…”