Recent methodological advances in quantitative wood anatomy have provided new insights into the climatic responses of radial growth at the scale of cell structure of tree rings. This study considered long-term chronol...Recent methodological advances in quantitative wood anatomy have provided new insights into the climatic responses of radial growth at the scale of cell structure of tree rings. This study considered long-term chronologies of tracheid measurements, indexed by a novel approach to separate their specific climatic responses from signal recorded in cell production(closely reflected in tree-ring width). To fill gaps in understanding the impact of climate on conifer xylem structure, Scots pine(Pinus sylvestris L.)trees > 200 years old were selected within the forest-steppe zone in southern Siberia. Such habitats undergo mild moisture deficits and the resulting climatic regulation of growth processes. Mean and maximum values of cell radial diameter and cell wall thickness were recorded for each tree ring.Despite a low level of climatogenic stress, components of cell chronologies independent of cambial activity were separated to obtain significant climatic signals revealing the timing of the specific stages of tracheid differentiation. Cell expansion lasted from mid-April to July and was impacted similarly to tree-ring width(stimulated by precipitation and stressed by heat), maximum cell size formed late June. A switch in the climatic responses of mean anatomical traits indicated transition to latewood in mid-July. Secondary wall deposition lasted until mid-September, suppressed by end of season temperatures. Generally, anatomical climatic responses were modulated by a less dry May and September compared with summer months.展开更多
Fast Fourier Transfer Image Processing was widely applied to the analysis of wood anatomy structure in re-cent years. The cells in the wood transverse section have obviously periodicity and regularity. FFT power spect...Fast Fourier Transfer Image Processing was widely applied to the analysis of wood anatomy structure in re-cent years. The cells in the wood transverse section have obviously periodicity and regularity. FFT power spectral patternscan extract the periodic characteristics so that they can be compared. identified and classified quaytitatively. This paperSummarizes the application of FFT image analysis in wood science and the general way to study wood anatomy by FFT.展开更多
Morphological features and anatomical variations are described and illustrated in detail for four native species of Legnminosae grown in arid sandy regions in China, which are Hedysarum scoparium Fisch.et Mey., Caraga...Morphological features and anatomical variations are described and illustrated in detail for four native species of Legnminosae grown in arid sandy regions in China, which are Hedysarum scoparium Fisch.et Mey., Caragana korshiskii Kom., Lespedeza bicolor Turcz. and Ammopiptanthus mongolicus （Maxim. ex Kom.） Cheng f. All species showed similar morphological features： distinct growth ring boundaries, ring to semi-ring-porosity, simple perforation plates, alternate intervessel pitting, nonseptate fibers, paratracheal confluent axial parenchyma, helical thickenings and heterocellular rays. However, the vessel arrangement and their quantitative features were different. A. mongolicus had smaller vessel diameters and larger vessel fi＇equency, while the values in the other three species were similar, but bigger than those in A. mongolicus. The variation of vessel lengths and fiber lengths along a horizontal direction showed an irregular tendency. There were significant differences in both fiber lengths and vessel element lengths among trees and within trees, except for A. mongolicus. The relationships between anatomical features of secondary xylem and the adaptability of these species to desert environments are also discussed.展开更多
基金supported by the Russian Science Foundation grant no. 23-44-00067the National Natural Science Foundation of China grant no.42261134537 in the framework of a joint Russian-Chinese project (fieldwork)by the Russian Ministry of Science and Higher Education,grant number FSRZ-2023-0007 (for data analysis)
文摘Recent methodological advances in quantitative wood anatomy have provided new insights into the climatic responses of radial growth at the scale of cell structure of tree rings. This study considered long-term chronologies of tracheid measurements, indexed by a novel approach to separate their specific climatic responses from signal recorded in cell production(closely reflected in tree-ring width). To fill gaps in understanding the impact of climate on conifer xylem structure, Scots pine(Pinus sylvestris L.)trees > 200 years old were selected within the forest-steppe zone in southern Siberia. Such habitats undergo mild moisture deficits and the resulting climatic regulation of growth processes. Mean and maximum values of cell radial diameter and cell wall thickness were recorded for each tree ring.Despite a low level of climatogenic stress, components of cell chronologies independent of cambial activity were separated to obtain significant climatic signals revealing the timing of the specific stages of tracheid differentiation. Cell expansion lasted from mid-April to July and was impacted similarly to tree-ring width(stimulated by precipitation and stressed by heat), maximum cell size formed late June. A switch in the climatic responses of mean anatomical traits indicated transition to latewood in mid-July. Secondary wall deposition lasted until mid-September, suppressed by end of season temperatures. Generally, anatomical climatic responses were modulated by a less dry May and September compared with summer months.
文摘Fast Fourier Transfer Image Processing was widely applied to the analysis of wood anatomy structure in re-cent years. The cells in the wood transverse section have obviously periodicity and regularity. FFT power spectral patternscan extract the periodic characteristics so that they can be compared. identified and classified quaytitatively. This paperSummarizes the application of FFT image analysis in wood science and the general way to study wood anatomy by FFT.
文摘Morphological features and anatomical variations are described and illustrated in detail for four native species of Legnminosae grown in arid sandy regions in China, which are Hedysarum scoparium Fisch.et Mey., Caragana korshiskii Kom., Lespedeza bicolor Turcz. and Ammopiptanthus mongolicus （Maxim. ex Kom.） Cheng f. All species showed similar morphological features： distinct growth ring boundaries, ring to semi-ring-porosity, simple perforation plates, alternate intervessel pitting, nonseptate fibers, paratracheal confluent axial parenchyma, helical thickenings and heterocellular rays. However, the vessel arrangement and their quantitative features were different. A. mongolicus had smaller vessel diameters and larger vessel fi＇equency, while the values in the other three species were similar, but bigger than those in A. mongolicus. The variation of vessel lengths and fiber lengths along a horizontal direction showed an irregular tendency. There were significant differences in both fiber lengths and vessel element lengths among trees and within trees, except for A. mongolicus. The relationships between anatomical features of secondary xylem and the adaptability of these species to desert environments are also discussed.
