Tree-ring standardized chronologies are developed by 78 cores collected from the eastern and western Helan Mountain. Statistical analysis shows that both the STD and RES chronologies correlate negatively with the temp...Tree-ring standardized chronologies are developed by 78 cores collected from the eastern and western Helan Mountain. Statistical analysis shows that both the STD and RES chronologies correlate negatively with the temperature of different periods of early half year, especially with January to August mean （JA） temperature, which means that JA temperature is one of the predominant limiting factors of tree growth in the Helan Mountain. Based on this analysis, we reconstructed JA temperature, and the explained variance is 43.3% （F=21.422, p〈0.001 ）. The comparatively high temperature periods in the reconstruction were： 1805-1818 1828-1857, 1899-1907, 1919-1931 and 1968-1995; and the comparatively low temperatu re periods happened in 1858-1872, 1883-1895 and 1935-1953. Ten-year moving average curve shows three slow uplifting trends： 1766-1853, 1862-1931 and 1944-1995. Each temperature increase was followed by a sudden temperature decrease about 10 years, that is to say, the JA temperature in the Helan Mountain is characterized by slow increase and sudden decrease. The 70- and 10.77-year periodicities detected in the temperature series correspond to the Gleissberg （80-year） and Schwabe （11-year） periodicities of solar activity respectively, the 2.11-2.62 years cycles are considered to be influenced by QBO （Quasi-Biennial-Oscillation） and the local environmental change.展开更多
Based on the analysis of the correlation between the tree-ring width of Pinus tabulaeformis and the climate factors in the western Hedong sandy land of Ningxia, a conversion equation between the annual precipitation a...Based on the analysis of the correlation between the tree-ring width of Pinus tabulaeformis and the climate factors in the western Hedong sandy land of Ningxia, a conversion equation between the annual precipitation and the tree-ring width since 1899 was reconstructed. The results of cross verification indicated that the conversion equation is stable and the reconstructed results are reliable. The result of reconstructed annual precipitation showed the remarkable fluctuation of precipitation and dry-to-wet variation before the 1940s. The smaller fluctuation and high frequent changes of precipitation occurred during the period of 1940s-1980s and after the 1980s the change trend of the precipitation became high periodic extent and low frequent. The study found that there were some coincidences with the climate change in Changling Mountains, Helan Mountains and the east of Qilian Mountains. The relatively dry periods in the beginning of 20th century, 1920s to 1930s, the end of the 20th century and 2004 to 2006 in the western Hedong sandy land of Ningxia accelerated the desertification, while the relatively humid period during the periods of the 1910s-1920s, 1930s-1940s and 1990s is favorable to prevent and control the desertification, and to weaken the climate warming and drying. The periods of annual precipitation variation in the western Hedong sandy land of Ningxia since 1899 are approximately 2-4 years, 5-7 years and 10 years.展开更多
Regional tree-ring width chronology of the Scots pine (Pinus sylvestris L.) was constructed from 8 sites in the forest-steppe belt situated in the foothills of the Selenga River basin, Russia. Moisture information con...Regional tree-ring width chronology of the Scots pine (Pinus sylvestris L.) was constructed from 8 sites in the forest-steppe belt situated in the foothills of the Selenga River basin, Russia. Moisture information contained in tree-ring width chronology was obtained through linear regression reconstruction models of annual August–July precipitation and annual water discharge of the Selenga River during the period 1767–2015. Comparison of the smoothed series allowed estimating long-term variation component of these moisture regime parameters with a high precision. At the same time, regional drought indices are less correlated with pine radial growth, because they have contribution of the other environmental variables, which are much less reflected in the tree-ring of the investigated pine forest stands. Reconstructed dynamic of the moisture regime parameters is supported by documental evident of many socially significant events in the regional history, such as crop failures caused by both droughts and floods, and catastrophic fire in the Irkutsk City in 1879. Also, dependence of the amount of precipitation in the study area on the atmospheric circulation in Central Asia is revealed to have a similar pattern with other regions, i.e., a negative relationship of precipitation with the development of large high atmospheric pressure area within its center in the Altai and Tianshan mountains.展开更多
Many difficult (often NP-complete) optimization problems can be solved efficiently on graphs of small tree-width with a given tree-decomposition.In this paper,it is discussed how to solve the minimum feedback vertex s...Many difficult (often NP-complete) optimization problems can be solved efficiently on graphs of small tree-width with a given tree-decomposition.In this paper,it is discussed how to solve the minimum feedback vertex set problem and the minimum vertex feedback edge set problem efficiently by using dynamic programming on a tree-decomposition.展开更多
August-June precipitation has been reconstructed back to AD 1720 for the northern Greater Higgnan Mountains, China, by use ofPinus sylvestris var. mongolica tree-ring width. The reconstruction explains the variance of...August-June precipitation has been reconstructed back to AD 1720 for the northern Greater Higgnan Mountains, China, by use ofPinus sylvestris var. mongolica tree-ring width. The reconstruction explains the variance of 39% in observed precipitation from 1973 to 2008. Some extremely dry/wet signals in historical documents and other precipitation reconstructions in previous studies are precisely captured in our reconstruction. Wet periods occurred during the periods of 1730 to 1746, 1789 to 1812, 1844 to 1903, 1920 to 1930, 1942 to 1961, and 1985 to 1998; while periods of 1747 to 1788, 1813 to 1843, 1904 to 1919, 1931 to 1941, and 1962 to 1984 were relatively dry. Power spectral and wavelet analyses demon- strated the existence of significant 24-year, 12-year, and 2-year cycles of variability.展开更多
Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and ...Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and tree-ring chronologies developed on northern and western slopes from the Lubanling in the Funiu Mountains.Correlation analyses showed that two chronologies were mainly limited by temperatures in the previous June-August and the com-bination of temperatures and moisture in the current May-July.The difference of the climate response to slopes was small but not negligible.Radial growth of the LBLO1 site on the northern slope was affected by the combined maximum and minimum temperatures,while that of the LBLO2 site was affected by maximum temperatures.With regards to moisture,radial growth of the trees on the north slope was influenced by the relative humidity in the current May-July,while on the western slope,it was affected by the relative humidity in the previous June-August,the current May-July and the precipitation in the current May-July.With the change in climate,the effects of the main limiting factors on growth on different slopes were visible to a certain extent,but the differences in response of trees on different slopes gradually decreased,which might be caused by factors such as different slope directions and the change in diurnal temperature range.These results may provide information for forest protection and ecological construction in this region,and a scientific reference for future climate reconstruction.展开更多
Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and ...Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and treering chronologies developed on northern and western slopes from the Lubanling in the Funiu Mountains.Correlation analyses showed that two chronologies were mainly limited by temperatures in the previous June–August and the combination of temperatures and moisture in the current May–July.The difference of the climate response to slopes was small but not negligible.Radial growth of the LBL01 site on the northern slope was affected by the combined maximum and minimum temperatures,while that of the LBL02 site was affected by maximum temperatures.With regards to moisture,radial growth of the trees on the north slope was influenced by the relative humidity in the current May–July,while on the western slope,it was affected by the relative humidity in the previous June–August,the current May–July and the precipitation in the current May–July.With the change in climate,the effects of the main limiting factors on growth on different slopes were visible to a certain extent,but the differences in response of trees on different slopes gradually decreased,which might be caused by factors such as different slope directions and the change in diurnal temperature range.These results may provide information for forest protection and ecological construction in this region,and a scientific reference for future climate reconstruction.展开更多
In dendroclimatology,tree ring chronology is ordinarily established to reveal the fluctuation law of climate change on the interannual,interdecadal,and centennial scales.However,since traditional dendrochronology can ...In dendroclimatology,tree ring chronology is ordinarily established to reveal the fluctuation law of climate change on the interannual,interdecadal,and centennial scales.However,since traditional dendrochronology can only use one variable(tree ring width)to reflect environmentally related information,this causes the richer information recorded in the tree rings to be discarded.In this study,we examined the potential of hyperspectral chronological indices(shortened as“hyperspectral index/indices”)with samples collected in Shennongjia woodland in central China.The correlation analysis of the tree ring series on different samples indicated that hyperspectral indices outperform the traditional width index in chronology statistics including Signal-to-noise Ratio(SNR)and Expressed Population Signal(EPS).The reliability test shows that hyperspectral chronologies have more periods reaching the threshold of EPS or Subsample Signal Strength(SSS)>0.85,which means that hyperspectral chronologies provide more reliable periods for accurate climate reconstruction.Based on this,chronologies built by the three dendroclimatic indices were used to reconstruct the average temperature changes in Shennongjia over the last 103 years.The reconstruction results indicate that in our study area,the traditional width index model failed the split-sample calibration test and exhibited a low reconstruction accuracy,while the hyperspectral index model has a higher explained variance of 46.4%(p<0.01),compared to the width index(21.4%)and the grayscale index(38.3%).Our research results show that hyperspectral indices have greater potential for climate reconstruction in regions with lower susceptibility to climate stress.This is attributed to their ability to effectively extract subtle climate signals from the spectral variations on the surface of tree rings.Such ring spectral changes may be caused by complex and currently unknown responses of the trees to the climate.展开更多
我国东北地区气候寒冷,低温事件会严重影响树木生长。水曲柳是东北地区珍贵的用材树种,目前关于其纤维解剖特征对低温的响应与适应策略还知之甚少。为此,以小兴安岭地区水曲柳子代测定林为研究对象,采用树轮年代学和木材解剖学方法,研...我国东北地区气候寒冷,低温事件会严重影响树木生长。水曲柳是东北地区珍贵的用材树种,目前关于其纤维解剖特征对低温的响应与适应策略还知之甚少。为此,以小兴安岭地区水曲柳子代测定林为研究对象,采用树轮年代学和木材解剖学方法,研究水曲柳纤维解剖特征与主要气候因子之间关系,明确低温对木材纤维解剖特征的影响。结果表明,小兴安岭地区水曲柳木纤维解剖特征具有较大的年际变化,木纤维细胞数量(fiber cell number,FN)、木纤维细胞总面积(total fiber cell area,TFA)与年轮宽度(ring width,RW)存在极显著正相关关系,在幼龄林阶段均呈现先升后降的变化趋势。木纤维细胞密度(fiber density,FD)和总体平均木纤维细胞壁增强指数(square of the total-to-bound ratio,(T/B)2)呈现逐年下降的趋势。平均木纤维细胞面积(mean fiber cell area,MFA)和木纤维细胞壁厚度(overall mean thickness of all fiber cell walls,CWTall)呈现逐年增加的趋势。水曲柳纤维解剖特征受温度影响较大,尤其是生长季最低温。低温事件使水曲柳的径向生长受到抑制,年轮宽度、木纤维细胞数量、平均木纤维细胞面积、木纤维细胞总面积和木纤维细胞占比(mean percentage of fiber cell area within xylem,RFTA)较非低温年分别显著下降32.6%、20.3%、22.4%、45.9%和9.4%,而木纤维细胞密度升高11.6%。在面对低温事件时,水曲柳会采取减少木纤维细胞数量、提高木纤维细胞密度这一相对保守的生存策略。研究结果为小兴安岭地区耐寒水曲柳选育提供科学依据。展开更多
在气候学、生态学、考古学等诸多领域,树木年轮蕴含的环境变迁与历史演替信息具有不可替代的研究价值。为解决传统年轮检测方法存在效率低、易受人为因素干扰等问题,研究提出DCW-YOLOv8年轮实例分割模型,运用可扩张残差(Dilation-wise R...在气候学、生态学、考古学等诸多领域,树木年轮蕴含的环境变迁与历史演替信息具有不可替代的研究价值。为解决传统年轮检测方法存在效率低、易受人为因素干扰等问题,研究提出DCW-YOLOv8年轮实例分割模型,运用可扩张残差(Dilation-wise Residual,DWR)注意力模块、轻量级通用上采样算子(Content-Aware ReAssembly of Features,CARAFE)、动态非单调聚焦机制边界框损失函数(Weighted Interpolation of Sequential Evidence for Intersection over Union,Wise-IoU)组合改进,并设计一种依据模型掩码获取年轮数量与宽度信息的检测方法。消融试验和前沿模型对比试验结果表明,DCWYOLOv8模型掩码平均精度mAP@0.50、mAP@0.50∶0.95提升,达到86.4%、53.6%,优于同类算法;注意力可视化比较结果表明,DCW-YOLOv8对年轮特征注意力更强;年轮信息检测结果表明,年轮数量检测准确率达到86.2%,年轮宽度检测误差在±0.5 mm范围内的占70%,总体平均误差为0.295 mm。研究提出的DCW-YOLOv8模型为年轮自动化检测提供新的思路和方法。展开更多
基金National Natural Science Foundation of China, No.40525004 No.40599420+2 种基金 No.90211081 No.40531003 No.40121303
文摘Tree-ring standardized chronologies are developed by 78 cores collected from the eastern and western Helan Mountain. Statistical analysis shows that both the STD and RES chronologies correlate negatively with the temperature of different periods of early half year, especially with January to August mean （JA） temperature, which means that JA temperature is one of the predominant limiting factors of tree growth in the Helan Mountain. Based on this analysis, we reconstructed JA temperature, and the explained variance is 43.3% （F=21.422, p〈0.001 ）. The comparatively high temperature periods in the reconstruction were： 1805-1818 1828-1857, 1899-1907, 1919-1931 and 1968-1995; and the comparatively low temperatu re periods happened in 1858-1872, 1883-1895 and 1935-1953. Ten-year moving average curve shows three slow uplifting trends： 1766-1853, 1862-1931 and 1944-1995. Each temperature increase was followed by a sudden temperature decrease about 10 years, that is to say, the JA temperature in the Helan Mountain is characterized by slow increase and sudden decrease. The 70- and 10.77-year periodicities detected in the temperature series correspond to the Gleissberg （80-year） and Schwabe （11-year） periodicities of solar activity respectively, the 2.11-2.62 years cycles are considered to be influenced by QBO （Quasi-Biennial-Oscillation） and the local environmental change.
基金supported by the National Natural Science Foundation of China (40801004, 40671184)the Research Fund for the Doctoral Program of Higher Education (20070027019)
文摘Based on the analysis of the correlation between the tree-ring width of Pinus tabulaeformis and the climate factors in the western Hedong sandy land of Ningxia, a conversion equation between the annual precipitation and the tree-ring width since 1899 was reconstructed. The results of cross verification indicated that the conversion equation is stable and the reconstructed results are reliable. The result of reconstructed annual precipitation showed the remarkable fluctuation of precipitation and dry-to-wet variation before the 1940s. The smaller fluctuation and high frequent changes of precipitation occurred during the period of 1940s-1980s and after the 1980s the change trend of the precipitation became high periodic extent and low frequent. The study found that there were some coincidences with the climate change in Changling Mountains, Helan Mountains and the east of Qilian Mountains. The relatively dry periods in the beginning of 20th century, 1920s to 1930s, the end of the 20th century and 2004 to 2006 in the western Hedong sandy land of Ningxia accelerated the desertification, while the relatively humid period during the periods of the 1910s-1920s, 1930s-1940s and 1990s is favorable to prevent and control the desertification, and to weaken the climate warming and drying. The periods of annual precipitation variation in the western Hedong sandy land of Ningxia since 1899 are approximately 2-4 years, 5-7 years and 10 years.
基金funded by the Russian Foundation for Basic Research (17-04-00315)the Russian Science Foundation (14-14-00219)
文摘Regional tree-ring width chronology of the Scots pine (Pinus sylvestris L.) was constructed from 8 sites in the forest-steppe belt situated in the foothills of the Selenga River basin, Russia. Moisture information contained in tree-ring width chronology was obtained through linear regression reconstruction models of annual August–July precipitation and annual water discharge of the Selenga River during the period 1767–2015. Comparison of the smoothed series allowed estimating long-term variation component of these moisture regime parameters with a high precision. At the same time, regional drought indices are less correlated with pine radial growth, because they have contribution of the other environmental variables, which are much less reflected in the tree-ring of the investigated pine forest stands. Reconstructed dynamic of the moisture regime parameters is supported by documental evident of many socially significant events in the regional history, such as crop failures caused by both droughts and floods, and catastrophic fire in the Irkutsk City in 1879. Also, dependence of the amount of precipitation in the study area on the atmospheric circulation in Central Asia is revealed to have a similar pattern with other regions, i.e., a negative relationship of precipitation with the development of large high atmospheric pressure area within its center in the Altai and Tianshan mountains.
基金Partially supported by the National Natural Science Foundation of China( 1 0 2 71 0 65
文摘Many difficult (often NP-complete) optimization problems can be solved efficiently on graphs of small tree-width with a given tree-decomposition.In this paper,it is discussed how to solve the minimum feedback vertex set problem and the minimum vertex feedback edge set problem efficiently by using dynamic programming on a tree-decomposition.
基金supported by the Climate Change Special Project of China Meteorological Administration (CCSF201438)the Meteorology Public Welfare Industry Research Special Project (GYHY201106013-3 and GYHY200806011)the Basic Research Operating Expenses of the Central-level Public Welfare Research Institutes (IDM201204)
文摘August-June precipitation has been reconstructed back to AD 1720 for the northern Greater Higgnan Mountains, China, by use ofPinus sylvestris var. mongolica tree-ring width. The reconstruction explains the variance of 39% in observed precipitation from 1973 to 2008. Some extremely dry/wet signals in historical documents and other precipitation reconstructions in previous studies are precisely captured in our reconstruction. Wet periods occurred during the periods of 1730 to 1746, 1789 to 1812, 1844 to 1903, 1920 to 1930, 1942 to 1961, and 1985 to 1998; while periods of 1747 to 1788, 1813 to 1843, 1904 to 1919, 1931 to 1941, and 1962 to 1984 were relatively dry. Power spectral and wavelet analyses demon- strated the existence of significant 24-year, 12-year, and 2-year cycles of variability.
基金supported by the National Natural Science Foundation of China (No.42077417,41671042).
文摘Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and tree-ring chronologies developed on northern and western slopes from the Lubanling in the Funiu Mountains.Correlation analyses showed that two chronologies were mainly limited by temperatures in the previous June-August and the com-bination of temperatures and moisture in the current May-July.The difference of the climate response to slopes was small but not negligible.Radial growth of the LBLO1 site on the northern slope was affected by the combined maximum and minimum temperatures,while that of the LBLO2 site was affected by maximum temperatures.With regards to moisture,radial growth of the trees on the north slope was influenced by the relative humidity in the current May-July,while on the western slope,it was affected by the relative humidity in the previous June-August,the current May-July and the precipitation in the current May-July.With the change in climate,the effects of the main limiting factors on growth on different slopes were visible to a certain extent,but the differences in response of trees on different slopes gradually decreased,which might be caused by factors such as different slope directions and the change in diurnal temperature range.These results may provide information for forest protection and ecological construction in this region,and a scientific reference for future climate reconstruction.
基金the National Natural Science Foundation of China(No.4207741741671042)。
文摘Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and treering chronologies developed on northern and western slopes from the Lubanling in the Funiu Mountains.Correlation analyses showed that two chronologies were mainly limited by temperatures in the previous June–August and the combination of temperatures and moisture in the current May–July.The difference of the climate response to slopes was small but not negligible.Radial growth of the LBL01 site on the northern slope was affected by the combined maximum and minimum temperatures,while that of the LBL02 site was affected by maximum temperatures.With regards to moisture,radial growth of the trees on the north slope was influenced by the relative humidity in the current May–July,while on the western slope,it was affected by the relative humidity in the previous June–August,the current May–July and the precipitation in the current May–July.With the change in climate,the effects of the main limiting factors on growth on different slopes were visible to a certain extent,but the differences in response of trees on different slopes gradually decreased,which might be caused by factors such as different slope directions and the change in diurnal temperature range.These results may provide information for forest protection and ecological construction in this region,and a scientific reference for future climate reconstruction.
基金supported by the National Natural Science Foundation of China(NSFC)Projects[grant numbers 42271476 and 41771227]Key Technology Projects of the Hubei Provincial Company of the China National Tobacco Corporation(grant number 027Y2021-020 and 027Y2022-006)Young Scholar of Wuhan University 351 Talent Program[grant number 202017].
文摘In dendroclimatology,tree ring chronology is ordinarily established to reveal the fluctuation law of climate change on the interannual,interdecadal,and centennial scales.However,since traditional dendrochronology can only use one variable(tree ring width)to reflect environmentally related information,this causes the richer information recorded in the tree rings to be discarded.In this study,we examined the potential of hyperspectral chronological indices(shortened as“hyperspectral index/indices”)with samples collected in Shennongjia woodland in central China.The correlation analysis of the tree ring series on different samples indicated that hyperspectral indices outperform the traditional width index in chronology statistics including Signal-to-noise Ratio(SNR)and Expressed Population Signal(EPS).The reliability test shows that hyperspectral chronologies have more periods reaching the threshold of EPS or Subsample Signal Strength(SSS)>0.85,which means that hyperspectral chronologies provide more reliable periods for accurate climate reconstruction.Based on this,chronologies built by the three dendroclimatic indices were used to reconstruct the average temperature changes in Shennongjia over the last 103 years.The reconstruction results indicate that in our study area,the traditional width index model failed the split-sample calibration test and exhibited a low reconstruction accuracy,while the hyperspectral index model has a higher explained variance of 46.4%(p<0.01),compared to the width index(21.4%)and the grayscale index(38.3%).Our research results show that hyperspectral indices have greater potential for climate reconstruction in regions with lower susceptibility to climate stress.This is attributed to their ability to effectively extract subtle climate signals from the spectral variations on the surface of tree rings.Such ring spectral changes may be caused by complex and currently unknown responses of the trees to the climate.
文摘我国东北地区气候寒冷,低温事件会严重影响树木生长。水曲柳是东北地区珍贵的用材树种,目前关于其纤维解剖特征对低温的响应与适应策略还知之甚少。为此,以小兴安岭地区水曲柳子代测定林为研究对象,采用树轮年代学和木材解剖学方法,研究水曲柳纤维解剖特征与主要气候因子之间关系,明确低温对木材纤维解剖特征的影响。结果表明,小兴安岭地区水曲柳木纤维解剖特征具有较大的年际变化,木纤维细胞数量(fiber cell number,FN)、木纤维细胞总面积(total fiber cell area,TFA)与年轮宽度(ring width,RW)存在极显著正相关关系,在幼龄林阶段均呈现先升后降的变化趋势。木纤维细胞密度(fiber density,FD)和总体平均木纤维细胞壁增强指数(square of the total-to-bound ratio,(T/B)2)呈现逐年下降的趋势。平均木纤维细胞面积(mean fiber cell area,MFA)和木纤维细胞壁厚度(overall mean thickness of all fiber cell walls,CWTall)呈现逐年增加的趋势。水曲柳纤维解剖特征受温度影响较大,尤其是生长季最低温。低温事件使水曲柳的径向生长受到抑制,年轮宽度、木纤维细胞数量、平均木纤维细胞面积、木纤维细胞总面积和木纤维细胞占比(mean percentage of fiber cell area within xylem,RFTA)较非低温年分别显著下降32.6%、20.3%、22.4%、45.9%和9.4%,而木纤维细胞密度升高11.6%。在面对低温事件时,水曲柳会采取减少木纤维细胞数量、提高木纤维细胞密度这一相对保守的生存策略。研究结果为小兴安岭地区耐寒水曲柳选育提供科学依据。
文摘在气候学、生态学、考古学等诸多领域,树木年轮蕴含的环境变迁与历史演替信息具有不可替代的研究价值。为解决传统年轮检测方法存在效率低、易受人为因素干扰等问题,研究提出DCW-YOLOv8年轮实例分割模型,运用可扩张残差(Dilation-wise Residual,DWR)注意力模块、轻量级通用上采样算子(Content-Aware ReAssembly of Features,CARAFE)、动态非单调聚焦机制边界框损失函数(Weighted Interpolation of Sequential Evidence for Intersection over Union,Wise-IoU)组合改进,并设计一种依据模型掩码获取年轮数量与宽度信息的检测方法。消融试验和前沿模型对比试验结果表明,DCWYOLOv8模型掩码平均精度mAP@0.50、mAP@0.50∶0.95提升,达到86.4%、53.6%,优于同类算法;注意力可视化比较结果表明,DCW-YOLOv8对年轮特征注意力更强;年轮信息检测结果表明,年轮数量检测准确率达到86.2%,年轮宽度检测误差在±0.5 mm范围内的占70%,总体平均误差为0.295 mm。研究提出的DCW-YOLOv8模型为年轮自动化检测提供新的思路和方法。
