Pub Date : 2020-09-10DOI: 10.1080/04353676.2020.1813983
G. Leonelli, A. Chelli, M. Consonni, C. Lorenzo, P. Gattinoni
ABSTRACT An integrated approach including dendrometric and dendrogeomorphological analysis, geotechnical monitoring and numerical modeling was established on a reactivating landslide in a forested Deep-Seated Gravitational Slope Deformation (DSGSD) area in Valtellina, Italy, in order to define the distribution of surface displacements in space and time as well as to identify the triggering factors (i.e. precipitation and a recent road tunneling). By means of a normalized difference eccentricity index (EI), we dated with annual resolution the surface displacements occurred over the period 1980–2016: the instability signals spread from the upper portion of the landslide (C) in 1980s to the middle section (B) especially in the 2000s, when they also occurred in the lowest portion (A). Mean Absolute EI (MAEI index) highlighted the intensity of the displacement signals, whereas changes in the MAEI series (dMAEI index) allowed to find correspondences between precipitation input and tree-ring eccentricity. A diagnostic test applied to these correspondences showed an overall accuracy of 0.74 and allowed to determine the precipitation threshold values acting as triggering factors. Topographic monitoring networks in 2016 revealed displacements <1 mm in the upper portion of the landslide, whereas the middle and lowest portion displacements were ranging 1–10 mm. The inclinometric probes confirmed the same trend for in-depth displacements, pointing out multiple sliding surfaces. A numerical stress-strain model, integrating information both from the instrumental and the dendrochronological approaches, provided information on the slope dynamics and its controlling factors, including groundwater flow conditions and the recent tunneling, thus allowing a comprehensive assessment of the geomorphological hazard.
{"title":"Multi-decadal dating of surface slope movements in forested DSGSD areas of the European Alps: detecting precipitation triggering factors","authors":"G. Leonelli, A. Chelli, M. Consonni, C. Lorenzo, P. Gattinoni","doi":"10.1080/04353676.2020.1813983","DOIUrl":"https://doi.org/10.1080/04353676.2020.1813983","url":null,"abstract":"ABSTRACT An integrated approach including dendrometric and dendrogeomorphological analysis, geotechnical monitoring and numerical modeling was established on a reactivating landslide in a forested Deep-Seated Gravitational Slope Deformation (DSGSD) area in Valtellina, Italy, in order to define the distribution of surface displacements in space and time as well as to identify the triggering factors (i.e. precipitation and a recent road tunneling). By means of a normalized difference eccentricity index (EI), we dated with annual resolution the surface displacements occurred over the period 1980–2016: the instability signals spread from the upper portion of the landslide (C) in 1980s to the middle section (B) especially in the 2000s, when they also occurred in the lowest portion (A). Mean Absolute EI (MAEI index) highlighted the intensity of the displacement signals, whereas changes in the MAEI series (dMAEI index) allowed to find correspondences between precipitation input and tree-ring eccentricity. A diagnostic test applied to these correspondences showed an overall accuracy of 0.74 and allowed to determine the precipitation threshold values acting as triggering factors. Topographic monitoring networks in 2016 revealed displacements <1 mm in the upper portion of the landslide, whereas the middle and lowest portion displacements were ranging 1–10 mm. The inclinometric probes confirmed the same trend for in-depth displacements, pointing out multiple sliding surfaces. A numerical stress-strain model, integrating information both from the instrumental and the dendrochronological approaches, provided information on the slope dynamics and its controlling factors, including groundwater flow conditions and the recent tunneling, thus allowing a comprehensive assessment of the geomorphological hazard.","PeriodicalId":55112,"journal":{"name":"Geografiska Annaler Series A-Physical Geography","volume":"238 1","pages":"8 - 32"},"PeriodicalIF":1.5,"publicationDate":"2020-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76873174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-04DOI: 10.1080/04353676.2020.1796336
Yilin Ran, Lingnan Zhang, Rui Wang, Shoudong Zhao, Xiaohong Liu
ABSTRACT The effects of climate warming are widely recognized; however, some studies have suggested that the rate of warming has slowed since the end of the twentieth century. However, the relationships between climate and the radial growth of trees during different periods of climate change have yet to be investigated fully. In the present study, tree-ring core samples were collected from Picea crassifolia and Juniperus przewalskii in the Qilian Mountains of northwest China to study the relationships between climate and radial growth. The core samples were divided into two groups: one with significant tree-growth reduction and another with insignificant reduction. Trees showing with significant growth reduction were more sensitive to climate change than trees showing insignificant growth reduction during the period of climate warming. P. crassifolia exhibited a stronger response to precipitation during May–June of the current year and from August of the previous year to June of the current year, both before and after climate warming. P. crassifolia exhibited a positive coherence with precipitation from August–September of the previous year and a negative coherence with the temperature of the current June during climate warming. After climate warming, J. przewalskii responded positively to precipitation in the current May and from the previous August to the current May. J. przewalskii also responded positively to temperature during January–February of the current year after warming. P. crassifolia responded to precipitation more strongly than J. przewalskii, whereas J. przewalskii showed a closer relationship to temperature than P. crassifolia.
{"title":"Diverse climate sensitivities in Picea crassifolia and Juniperus przewalskii promote different responses to climate warming in Qilian Mountains, northwest China","authors":"Yilin Ran, Lingnan Zhang, Rui Wang, Shoudong Zhao, Xiaohong Liu","doi":"10.1080/04353676.2020.1796336","DOIUrl":"https://doi.org/10.1080/04353676.2020.1796336","url":null,"abstract":"ABSTRACT The effects of climate warming are widely recognized; however, some studies have suggested that the rate of warming has slowed since the end of the twentieth century. However, the relationships between climate and the radial growth of trees during different periods of climate change have yet to be investigated fully. In the present study, tree-ring core samples were collected from Picea crassifolia and Juniperus przewalskii in the Qilian Mountains of northwest China to study the relationships between climate and radial growth. The core samples were divided into two groups: one with significant tree-growth reduction and another with insignificant reduction. Trees showing with significant growth reduction were more sensitive to climate change than trees showing insignificant growth reduction during the period of climate warming. P. crassifolia exhibited a stronger response to precipitation during May–June of the current year and from August of the previous year to June of the current year, both before and after climate warming. P. crassifolia exhibited a positive coherence with precipitation from August–September of the previous year and a negative coherence with the temperature of the current June during climate warming. After climate warming, J. przewalskii responded positively to precipitation in the current May and from the previous August to the current May. J. przewalskii also responded positively to temperature during January–February of the current year after warming. P. crassifolia responded to precipitation more strongly than J. przewalskii, whereas J. przewalskii showed a closer relationship to temperature than P. crassifolia.","PeriodicalId":55112,"journal":{"name":"Geografiska Annaler Series A-Physical Geography","volume":"24 1","pages":"33 - 50"},"PeriodicalIF":1.5,"publicationDate":"2020-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83214716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-02DOI: 10.1080/04353676.2020.1786943
Shulong Yu, Tongwen Zhang, Shengxia Jiang, Ruibo Zhang, L. Qin, Huaming Shang, Heli Zhang
ABSTRACT We selected four sampling areas to collect tree-ring samples along an elevation gradient on north-facing slopes in three regions of the Tien Shan Mountains. Samples were collected at sites located at intervals of about 100 m.a.s.l. in each sampling area. For all sampling sites, the mean tree age, mean sensitivity, and standard deviation of the minimum density chronologies were associated with elevation. Within the same region and between different areas, the consistency of the minimum density of tree rings was highest in the high-elevation sites, followed by the low-elevation sites, and lowest in the mid-elevation forest. Marked changes in slope aspect and inclination affected the consistency of the minimum density in the same area. Significant differences were observed in tree-ring density at 2000–2200 m.a.s.l. Several environmental factors influenced the variation in minimum density of tree rings at different elevations; the factors that were significantly affected by high elevation were observed in the western and central regions of the Tien Shan. High-frequency oscillation was the main reason affecting the change in minimum density and significant differences were observed in medium-frequency oscillations before and after the 1980s.
{"title":"Tree-ring minimum density chronologies of Picea schrenkiana along an elevation gradient in the Tien Shan Mountains, China","authors":"Shulong Yu, Tongwen Zhang, Shengxia Jiang, Ruibo Zhang, L. Qin, Huaming Shang, Heli Zhang","doi":"10.1080/04353676.2020.1786943","DOIUrl":"https://doi.org/10.1080/04353676.2020.1786943","url":null,"abstract":"ABSTRACT We selected four sampling areas to collect tree-ring samples along an elevation gradient on north-facing slopes in three regions of the Tien Shan Mountains. Samples were collected at sites located at intervals of about 100 m.a.s.l. in each sampling area. For all sampling sites, the mean tree age, mean sensitivity, and standard deviation of the minimum density chronologies were associated with elevation. Within the same region and between different areas, the consistency of the minimum density of tree rings was highest in the high-elevation sites, followed by the low-elevation sites, and lowest in the mid-elevation forest. Marked changes in slope aspect and inclination affected the consistency of the minimum density in the same area. Significant differences were observed in tree-ring density at 2000–2200 m.a.s.l. Several environmental factors influenced the variation in minimum density of tree rings at different elevations; the factors that were significantly affected by high elevation were observed in the western and central regions of the Tien Shan. High-frequency oscillation was the main reason affecting the change in minimum density and significant differences were observed in medium-frequency oscillations before and after the 1980s.","PeriodicalId":55112,"journal":{"name":"Geografiska Annaler Series A-Physical Geography","volume":"33 1","pages":"209 - 221"},"PeriodicalIF":1.5,"publicationDate":"2020-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73860914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-02DOI: 10.1080/04353676.2020.1806659
H. Linderholm
{"title":"Introduction to the special issue on ‘Tree rings, Environment and Tropical Forests’","authors":"H. Linderholm","doi":"10.1080/04353676.2020.1806659","DOIUrl":"https://doi.org/10.1080/04353676.2020.1806659","url":null,"abstract":"","PeriodicalId":55112,"journal":{"name":"Geografiska Annaler Series A-Physical Geography","volume":"5 1","pages":"183 - 184"},"PeriodicalIF":1.5,"publicationDate":"2020-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83859511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT In this study, a 177-year April–June Palmer Drought Severity Index (PDSI) for the southern slopes of the Altay Mountains (China) was reconstructed based on the earlywood width of 96 Siberian spruce (Picea obovata Ledeb.) samples located at eight different sites. The reconstructed PDSI tracked the observed data well (r = 0.723, p < .0001, n = 52). This PDSI reconstruction captures some drought years and periods noted in historical documents, and it agrees well with other hydroclimatic reconstructions for the surrounding area. The 22-, 11-, 2.3-, and 2.1-year cycles of the reconstruction and the spatial correlation with sea surface temperature revealed that the variability of the PDSI for the study area might be influenced by both the Schwabe cycle of solar activity and the interannual oscillation of land–atmosphere–ocean circulation systems. Spatial correlation also showed the reconstruction contained climatic signals, being representative of a larger area extending from northern Xinjiang to northeastern Kazakhstan and a part of southern Russia. Synoptic climatology analysis revealed a relationship between anomalous atmospheric circulation and wet/dry years on the southern slopes of the Altay Mountains in China and its surrounding area.
摘要本研究基于位于8个不同地点的96个西伯利亚云杉(Picea obovata Ledeb.)样本的早期木材宽度，重建了中国阿勒泰山脉南坡177年4 - 6月的Palmer干旱严重指数(PDSI)。重建的PDSI能很好地跟踪观测数据(r = 0.723, p < 0.0001, n = 52)。PDSI重建记录了历史文献中记录的一些干旱年份和时期，它与周围地区的其他水文气候重建结果吻合得很好。22年、11年、2.3年和2.1年的重建周期及其与海温的空间相关性表明，研究区PDSI的变化可能受到太阳活动Schwabe周期和陆-气-海环流系统年际振荡的影响。空间相关性还表明，重建包含气候信号，代表了从新疆北部到哈萨克斯坦东北部和俄罗斯南部部分地区的更大范围。天气气候学分析揭示了中国阿勒泰山脉南坡及周边地区大气环流异常与干湿年的关系。
{"title":"Drought reconstruction based on tree-ring earlywood of Picea obovata Ledeb. for the southern Altay Mountains","authors":"Shengxia Jiang, Tongwen Zhang, Yu-jiang Yuan, Shulong Yu, Huaming Shang, Ruibo Zhang","doi":"10.1080/04353676.2020.1773060","DOIUrl":"https://doi.org/10.1080/04353676.2020.1773060","url":null,"abstract":"ABSTRACT In this study, a 177-year April–June Palmer Drought Severity Index (PDSI) for the southern slopes of the Altay Mountains (China) was reconstructed based on the earlywood width of 96 Siberian spruce (Picea obovata Ledeb.) samples located at eight different sites. The reconstructed PDSI tracked the observed data well (r = 0.723, p < .0001, n = 52). This PDSI reconstruction captures some drought years and periods noted in historical documents, and it agrees well with other hydroclimatic reconstructions for the surrounding area. The 22-, 11-, 2.3-, and 2.1-year cycles of the reconstruction and the spatial correlation with sea surface temperature revealed that the variability of the PDSI for the study area might be influenced by both the Schwabe cycle of solar activity and the interannual oscillation of land–atmosphere–ocean circulation systems. Spatial correlation also showed the reconstruction contained climatic signals, being representative of a larger area extending from northern Xinjiang to northeastern Kazakhstan and a part of southern Russia. Synoptic climatology analysis revealed a relationship between anomalous atmospheric circulation and wet/dry years on the southern slopes of the Altay Mountains in China and its surrounding area.","PeriodicalId":55112,"journal":{"name":"Geografiska Annaler Series A-Physical Geography","volume":"31 1","pages":"267 - 286"},"PeriodicalIF":1.5,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74074773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-14DOI: 10.1080/04353676.2020.1774243
G. Bao, Yu Liu, Na Liu, Hongtao Wang
ABSTRACT Tree-ring chronologies of Pinus tabulaeformis from three sampling sites in southeastern Gansu Province in China and growth-related parameters calculated from daily average temperatures were utilized to explore the response features of tree radial growth to onset and cessation date, duration and accumulated temperature. The results indicated that the three chronologies exhibited a significantly positive correlation with the temperature (12°C) of the onset date (p<0.05), which is consistent with the initial threshold temperature that occurred in May based on radial growth monitoring nearby. The tree-ring chronology from the Taihe Mountains located in a relatively more arid area had a significantly negative correlation with cessation dates in late September with temperatures of 12.5-13.5°C (p<0.05). The threshold associated with the duration and accumulated temperature in the two chronologies from the Taihe and Xiaolong Mountains occurred at 12°C (p<0.01). Significantly negative correlations were found between the chronology from the Guiqing Mountains and accumulated temperature from 5°C to 15°C (p<0.05). Soil moisture stress caused by increasing temperatures and accumulated temperatures during the main growing season from May to September is the main limiting factor for the radial growth of trees. Our results are consistent with findings based on monthly climate data and tree-ring width indexes, indicating that the current research is reliable and effective.
{"title":"Radial growth response of Pinus tabulaeformis to temperature during the growth season in southeastern Gansu, China","authors":"G. Bao, Yu Liu, Na Liu, Hongtao Wang","doi":"10.1080/04353676.2020.1774243","DOIUrl":"https://doi.org/10.1080/04353676.2020.1774243","url":null,"abstract":"ABSTRACT Tree-ring chronologies of Pinus tabulaeformis from three sampling sites in southeastern Gansu Province in China and growth-related parameters calculated from daily average temperatures were utilized to explore the response features of tree radial growth to onset and cessation date, duration and accumulated temperature. The results indicated that the three chronologies exhibited a significantly positive correlation with the temperature (12°C) of the onset date (p<0.05), which is consistent with the initial threshold temperature that occurred in May based on radial growth monitoring nearby. The tree-ring chronology from the Taihe Mountains located in a relatively more arid area had a significantly negative correlation with cessation dates in late September with temperatures of 12.5-13.5°C (p<0.05). The threshold associated with the duration and accumulated temperature in the two chronologies from the Taihe and Xiaolong Mountains occurred at 12°C (p<0.01). Significantly negative correlations were found between the chronology from the Guiqing Mountains and accumulated temperature from 5°C to 15°C (p<0.05). Soil moisture stress caused by increasing temperatures and accumulated temperatures during the main growing season from May to September is the main limiting factor for the radial growth of trees. Our results are consistent with findings based on monthly climate data and tree-ring width indexes, indicating that the current research is reliable and effective.","PeriodicalId":55112,"journal":{"name":"Geografiska Annaler Series A-Physical Geography","volume":"8 1","pages":"185 - 195"},"PeriodicalIF":1.5,"publicationDate":"2020-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72989721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-05DOI: 10.1080/04353676.2020.1774244
A. Hall, M. Krabbendam, Mikis van Boeckel, B. Goodfellow, C. Hättestrand, J. Heyman, Romesh Palamakumbura, A. Stroeven, J. Näslund
ABSTRACT In low relief Precambrian gneiss terrain in eastern Sweden, abraded bedrock surfaces were ripped apart by the Fennoscandian Ice Sheet. The resultant boulder spreads are covers of large, angular boulders, many with glacial transport distances of 1–100 m. Boulder spreads occur alongside partly disintegrated roches moutonnées and associated fracture caves, and are associated with disrupted bedrock, which shows extensive fracture dilation in the near surface. These features are distributed in ice-flow parallel belts up to 10 km wide and extend over distances of >500 km. Our hypothesis is that the assemblage results from (1) hydraulic jacking and bedrock disruption, (2) subglacial ripping and (3) displacement, transport and final deposition of boulders. Soft sediment fills indicate jacking and dilation of pre-existing bedrock fractures by groundwater overpressure below the ice sheet. Overpressure reduces frictional resistance along fractures. Where ice traction overcomes this resistance, the rock mass strength is exceeded, resulting in disintegration of rock surfaces and ripping apart into separate blocks. Further movement and deposition create boulder spreads and moraines. Short boulder transport distances and high angularity indicate that glacial ripping operated late in the last deglaciation. The depths of rock mobilized in boulder spreads are estimated as 1–4 m. This compares with 0.6–1.6 m depths of erosion during the last glaciation derived from cosmogenic nuclide inventories of samples from bedrock surfaces without evidence of disruption. Glacially disrupted and ripped bedrock is also made ready for removal by future ice sheets. Hence glacial ripping is a highly effective process of glacial erosion.
{"title":"Glacial ripping: geomorphological evidence from Sweden for a new process of glacial erosion","authors":"A. Hall, M. Krabbendam, Mikis van Boeckel, B. Goodfellow, C. Hättestrand, J. Heyman, Romesh Palamakumbura, A. Stroeven, J. Näslund","doi":"10.1080/04353676.2020.1774244","DOIUrl":"https://doi.org/10.1080/04353676.2020.1774244","url":null,"abstract":"ABSTRACT In low relief Precambrian gneiss terrain in eastern Sweden, abraded bedrock surfaces were ripped apart by the Fennoscandian Ice Sheet. The resultant boulder spreads are covers of large, angular boulders, many with glacial transport distances of 1–100 m. Boulder spreads occur alongside partly disintegrated roches moutonnées and associated fracture caves, and are associated with disrupted bedrock, which shows extensive fracture dilation in the near surface. These features are distributed in ice-flow parallel belts up to 10 km wide and extend over distances of >500 km. Our hypothesis is that the assemblage results from (1) hydraulic jacking and bedrock disruption, (2) subglacial ripping and (3) displacement, transport and final deposition of boulders. Soft sediment fills indicate jacking and dilation of pre-existing bedrock fractures by groundwater overpressure below the ice sheet. Overpressure reduces frictional resistance along fractures. Where ice traction overcomes this resistance, the rock mass strength is exceeded, resulting in disintegration of rock surfaces and ripping apart into separate blocks. Further movement and deposition create boulder spreads and moraines. Short boulder transport distances and high angularity indicate that glacial ripping operated late in the last deglaciation. The depths of rock mobilized in boulder spreads are estimated as 1–4 m. This compares with 0.6–1.6 m depths of erosion during the last glaciation derived from cosmogenic nuclide inventories of samples from bedrock surfaces without evidence of disruption. Glacially disrupted and ripped bedrock is also made ready for removal by future ice sheets. Hence glacial ripping is a highly effective process of glacial erosion.","PeriodicalId":55112,"journal":{"name":"Geografiska Annaler Series A-Physical Geography","volume":"9 1","pages":"333 - 353"},"PeriodicalIF":1.5,"publicationDate":"2020-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80843830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-01DOI: 10.1080/04353676.2020.1769364
Maowei Bai, Zhipeng Dong, Dai Chen, Huaizhou Zheng, Feifei Zhou, Xinguang Cao, T. Ou, Keyan Fang
ABSTRACT China holds the world’s largest area of planted forests, which play a crucial role in mitigating climate change. Knowledge gaps remain on the responses of the growth of planted forests to climate changes in China, particularly for their long-term changes. This study compared the long-term tree-ring growth patterns and their responses to climate between planted and natural forests. We developed four chronologies from two typical conifer species of Pinus massoniana and Cunninghamia lanceolata from planted and natural forests in humid subtropical China. One chronology is to our knowledge the longest chronology from planted forests in China spanning since 1944. Tree growths of both natural and planted forests are generally limited by summer drought due to the hot and dry summer in this area. In general, tree rings of the natural forests are more sensitive to climate than planted forests as indicated by higher inter-series correlations, which agree with previous studies. The natural forests are more drought sensitive wheareas the planted forests are relatively more limited by temperature. The C. lanceolata forests showed more significant correlations with the accumulated drought than P. massoniana for both the natural and planted forests.
{"title":"Different responses of the radial growth of the planted and natural forests to climate change in humid subtropical China","authors":"Maowei Bai, Zhipeng Dong, Dai Chen, Huaizhou Zheng, Feifei Zhou, Xinguang Cao, T. Ou, Keyan Fang","doi":"10.1080/04353676.2020.1769364","DOIUrl":"https://doi.org/10.1080/04353676.2020.1769364","url":null,"abstract":"ABSTRACT China holds the world’s largest area of planted forests, which play a crucial role in mitigating climate change. Knowledge gaps remain on the responses of the growth of planted forests to climate changes in China, particularly for their long-term changes. This study compared the long-term tree-ring growth patterns and their responses to climate between planted and natural forests. We developed four chronologies from two typical conifer species of Pinus massoniana and Cunninghamia lanceolata from planted and natural forests in humid subtropical China. One chronology is to our knowledge the longest chronology from planted forests in China spanning since 1944. Tree growths of both natural and planted forests are generally limited by summer drought due to the hot and dry summer in this area. In general, tree rings of the natural forests are more sensitive to climate than planted forests as indicated by higher inter-series correlations, which agree with previous studies. The natural forests are more drought sensitive wheareas the planted forests are relatively more limited by temperature. The C. lanceolata forests showed more significant correlations with the accumulated drought than P. massoniana for both the natural and planted forests.","PeriodicalId":55112,"journal":{"name":"Geografiska Annaler Series A-Physical Geography","volume":"67 1","pages":"235 - 246"},"PeriodicalIF":1.5,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77417928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT We reconstructed the streamflow of the Qingshui River, which originates from the southern slopes of the central Tianshan Mountains in western China. The correlation between the hydrometeorological data and the tree-ring chronology indicated that the influences of temperature and precipitation on the radial growth of spruces were contrary in the different periods of the growth and non-growth seasons, while the highest correlation was found between the streamflow and the chronology. Based on the results of correlation analyses, a 475-year streamflow reconstruction from the previous August to the current July for the Qingshui River was reconstructed using the regional chronology. The reconstructed streamflow series matched observations well, with 43.1% of the variation in the observed streamflow. The streamflow reconstruction had a significantly positive correlation with a gridded PDSI dataset for an area closely corresponding to the Qingshui River watershed. The 50- and 2.0–3.0-year cycles of this reconstruction were consistent with other tree-ring based hydrometeorological reconstructions, and revealed the possible influences of the Gleissberg solar activity cycle and the interannual oscillations of land–atmospheric–ocean systems. The streamflow reconstruction for the Qingshui River captures some wet/drought years noted in historical documents and two turbulent periods after 1700 in Xinjiang, and agrees well with the streamflow reconstruction for the Kaidu River. Synoptic climatology analysis revealed a relationship between anomalous atmospheric circulation and wet/dry years for the Qingshui River watershed and its surrounding area. It is likely that the path of moisture in the wet years mainly originates from the Indian Ocean.
{"title":"A 475-year tree-ring-width record of streamflow for the Qingshui River originating in the southern slope of the central Tianshan Mountains, China","authors":"Tongwen Zhang, Huaming Shang, Yuting Fan, Shulong Yu, Ruibo Zhang, L. Qin, Shengxia Jiang","doi":"10.1080/04353676.2020.1769887","DOIUrl":"https://doi.org/10.1080/04353676.2020.1769887","url":null,"abstract":"ABSTRACT We reconstructed the streamflow of the Qingshui River, which originates from the southern slopes of the central Tianshan Mountains in western China. The correlation between the hydrometeorological data and the tree-ring chronology indicated that the influences of temperature and precipitation on the radial growth of spruces were contrary in the different periods of the growth and non-growth seasons, while the highest correlation was found between the streamflow and the chronology. Based on the results of correlation analyses, a 475-year streamflow reconstruction from the previous August to the current July for the Qingshui River was reconstructed using the regional chronology. The reconstructed streamflow series matched observations well, with 43.1% of the variation in the observed streamflow. The streamflow reconstruction had a significantly positive correlation with a gridded PDSI dataset for an area closely corresponding to the Qingshui River watershed. The 50- and 2.0–3.0-year cycles of this reconstruction were consistent with other tree-ring based hydrometeorological reconstructions, and revealed the possible influences of the Gleissberg solar activity cycle and the interannual oscillations of land–atmospheric–ocean systems. The streamflow reconstruction for the Qingshui River captures some wet/drought years noted in historical documents and two turbulent periods after 1700 in Xinjiang, and agrees well with the streamflow reconstruction for the Kaidu River. Synoptic climatology analysis revealed a relationship between anomalous atmospheric circulation and wet/dry years for the Qingshui River watershed and its surrounding area. It is likely that the path of moisture in the wet years mainly originates from the Indian Ocean.","PeriodicalId":55112,"journal":{"name":"Geografiska Annaler Series A-Physical Geography","volume":"57 1","pages":"247 - 266"},"PeriodicalIF":1.5,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76932875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-05-26DOI: 10.1080/04353676.2020.1763631
Yi Pan, Qiang Li, Yu Liu, Ruoshi Liu, Ruolan Deng
ABSTRACT The Northern China Plain is China’s traditional and important agricultural production base, where climate change in the past has significantly affected China in many aspects such as national agricultural policies, ecological construction and foreign trade exchanges. High-resolution paleoclimatology research reveals that the precipitation, relative humidity, and drought index in this area have a significantly variability in the past few centuries, and spectral analysis shows that each time series has an obviously short period coinciding with the El Niño-Southern Oscillation (ENSO) cycle. In this study, we summarized that ENSO signals in hydroclimate variations of northern China are probably from the Indian water vapor partly. In addition, the possible impact of hydroclimate variations in northern China on social and cultural events are briefly discussed considering historical records.
{"title":"Hydroclimate variations in the Northern China Plain and their possible socio-cultural influences","authors":"Yi Pan, Qiang Li, Yu Liu, Ruoshi Liu, Ruolan Deng","doi":"10.1080/04353676.2020.1763631","DOIUrl":"https://doi.org/10.1080/04353676.2020.1763631","url":null,"abstract":"ABSTRACT The Northern China Plain is China’s traditional and important agricultural production base, where climate change in the past has significantly affected China in many aspects such as national agricultural policies, ecological construction and foreign trade exchanges. High-resolution paleoclimatology research reveals that the precipitation, relative humidity, and drought index in this area have a significantly variability in the past few centuries, and spectral analysis shows that each time series has an obviously short period coinciding with the El Niño-Southern Oscillation (ENSO) cycle. In this study, we summarized that ENSO signals in hydroclimate variations of northern China are probably from the Indian water vapor partly. In addition, the possible impact of hydroclimate variations in northern China on social and cultural events are briefly discussed considering historical records.","PeriodicalId":55112,"journal":{"name":"Geografiska Annaler Series A-Physical Geography","volume":"5 1","pages":"287 - 296"},"PeriodicalIF":1.5,"publicationDate":"2020-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81987519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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