Detection of wood decay and cavities in living trees: A review

It has been established that wood decay and cavities in tree stems contribute significantly to tree failures. Several techniques have been reported by researchers for detecting wood decay and cavities in living trees. These techniques are reviewed in this study under two broad categories: invasive and non-invasive methods. The invasive methods include traditional (decay detecting drill, increment borer, and boroscope), radiographic, acoustic, and electrical resistivity techniques. The non-invasive methods comprise microwave scanning, magnetic resonance imaging, X-ray tomography, and traditional techniques involving the use of mallets. Two or more methods are usually combined to investigate the health status of a tree for comparison and validation of results. The prospects and challenges of the various techniques in diagnosing wood decay, cavities, and other structural defects in living trees are reported. This review aims to help researchers in this field identify areas of further work towards the efficient monitoring and management of forest and urban trees.

Relationship between climate variability and radial growth of Pinus montezumae Lamb. in Coyuca de Catalán, Guerrero

Introduction: Understanding the dendroclimatic potential of a species allows us to reconstruct the climate variability in the latitudes and altitudes of its distribution. Objective: To determine the potential of Pinus montezumae Lamb. to reconstruct climatic variables. Materials and methods: A total of 80 samples were extracted with a Pressler increment borer and dated, allowing growth rates to be generated. Average monthly rainfall and minimum and maximum temperature were obtained, and a response function analysis between growth rates and climate data was conducted. Results and discussion: Dated samples represented 75 % of the total. The COFECHA program indicated a correlation between series of r = 0.57 (P < 0.01) and a mean sensitivity of 0.31; P. montezumae is sufficiently sensitive to record climate variability. Three chronologies (standard, residual and arstan) covering 228 years (1790-2017) were generated for each of the three growth rates (total ring, early and latewood). The response function analysis showed that it is possible to reconstruct the spring rainfall and the May-July maximum temperature based on the total ring (r = 0.66; P < 0.01) and latewood (r = 0.35; P < 0.01) indices, respectively. Conclusion: Statistical parameters indicate that P. montezumae is an adequate proxy source for climate variability reconstruction studies.

Flood reconstruction using botanical evidence in Rapentosa catchment, in Marathon, Greece.

Botanical evidence has been used in the past for flash flood analysis, especially when instrumental data were scarce. This work focuses on the use of such evidence as a tool to study flash flood phenomena in Rapentosa torrent, in Marathon, Greece. To this aim, impact scars induced during past flood events on trees along the torrent , were considered water stage indicators and were used to determine discharge magnitude of these flow episodes. Samples extracted from the scarred specimens with the aid of an increment borer, were used to date these impacts wounds. 1-D h y-draulic modeling was used to provide a reconstruction of the highest-discharge event, while results were cross-examined with historical damages to verify the out-come of the analysis. Analysis showed a total of 22 impact wounds along the torrent indicating discharge values between 17.1 m3/s and 84.9 m3/s during past flow episodes. Three flash flood events were identified in 1996, 1998 and 2001. Hydraulic modeling of the 2001 event, which presented the highest flow values, illustrated its extent and water depth across the flood plain, presenting good correlation with the available documentary evidence.

Evaluating similarity of radial increments around tree stem circumference of European beech and Norway spruce from Central Europe

Extracting cores from a tree using an increment borer has been standard practice in dendrochronological studies for a long time. Although empirical rules exist regarding how many samples to take and which methodology to apply, comparatively few studies provide quantification of the similarity of relative tree-ring-widths (TRW) around the stem circumference. The aim of this study was therefore to precisely measure the similarity of standardised TRWs around the stem circumference and to provide objective suggestions for optimal core sampling of Norway spruce (Picea abies Karst. [L.]) and European beech (Fagus sylvatica L.) growing in Central European temperate forests.A large sample of cross-sectional discs was used from Norway spruce and European beech trees growing on various slopes, at different altitudes and biogeographic regions across the Czech Republic and Slovakia. The similarity of TRWs measured in different coring directions was analysed by testing the relativized TRW around the trunk (rTRW). Comparison of rTRWs revealed no significant differences between coring directions, indicating that the relative increment was the same around the radius. The results also showed the high similarity between the rTRWs to be independent of both slope inclination and altitude. Moreover, the reconstruction of proportional tree diameters and basal areas backward in time from one core sample and one measurement of tree diameter (basal area) at the time of sample extraction is possible with reasonable precision.

Effect of resin-tapping on the radial increment of Scots pine (Pinus sylvestris L.) – case study of a stand from Lidzbark Forest District

The study makes an attempt to evaluate the effect of resin-tapping on the radial increment of Scots pine (Pinus sylvestris L.). Increment cores were taken from two groups of trees: resin-tapped trees and normal trees growing in a 148-year-old pine stand in the Lidzbark Forest District. The cores were taken with the Pressler increment borer from two heights on the tree trunk: 1,30 m and 3,30 m. Using dendrochronological methods, real chronologies were built for each of the four analysed groups of cores. The value and variability of increments for each group were investigated in 20 and 40 year time periods, before and after the start of resin-tapping. In next step, the chronologies were compared and their coefficients of conformity were calculated. As a result, we can state that the radial increments were larger are at 1,3 m height after resin-tapping than before resin-tapping. There was also significant effect of resin-tapping on radial growth at the height 3,3 m, above the resin-tapping face.

COMPARISON OF THREE TREE‐RING SAMPLING METHODS FOR TRACE METAL ANALYSIS

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. Резюме Анализ годичных колец древесины предоставляет информацию о развитии дерева, что важно для инвентaризации леса, оценки воздействия на окружающую среду и мониторинга воздуха и почвы. Концентрации тяжелых металлов в годичных кольцах древесины зависят от их концентрации в окружающей среде и могут свидетельствовать об уровне загрязнения местности. Одним из важных этапов анализа древесины является взятие проб годичных колец. Для точного определения концентрации тяжелых металлов в годичных кольцах древесины важно избежать случайных погрешностей. В статье анализируются три метода взятия проб годичных колец древесины (дробление обычным долотом, круглым долотом и строгание) и сравниваются концентрации основных тяжелых металлов (Mn, Zn, Ni, Cu, Cr, Pb) в пробах, взятых каждым из названных методов. Средние концентрации тяжелых металлов при их измерении указанными методами достигали 1,695±0,161 мг/кг для Mn, 0,471±0,206 мг/кг для Zn, 0,487±0,202 мг/кг для Pb, 0,290±0,021 мг/кг для Cu, 0,210±0,023 мг/кг для Ni и 0,117±0,010 мг/кг для Cr. Эти концентрации тяжелых металлов аналогичны концентрациям в древесине сосны (Pinus sylvestris L) на данной исследуемой территории. При помощи статистического анализа [тест Андерсона–Дарлина (Anderson–Darlin), тест Крускаля–Валиса (Kruskal–Wallis), коэффициент вариации] выявлена лишь незначительная разница между концентрациями тяжелых металлов в годичных кольцах древесины, взятых уже названными методами. Методы дробления обычным долотом, круглым долотом и строгания могут успешно применяться для взятия проб годичных колец древесины, однако сверло „века“ предоставляет возможность взятия пробы без спиливания дерева.