Background： In the German Democratic Republic（GDR）, resin tapping in Scots pine（Pinus sylvestris L.） forests was a major economic activity, and resin-tapped stands are frequently found up until this day. In this ...Background： In the German Democratic Republic（GDR）, resin tapping in Scots pine（Pinus sylvestris L.） forests was a major economic activity, and resin-tapped stands are frequently found up until this day. In this study, we investigate how the mechanical damage caused by resin tapping affects the growth and climate sensitivity of Scots pine using a dendroecological approach.Methods： Tree-ring samples were collected from resin-tapped and non-tapped trees in two forest areas in northeastern Germany, and tree-growth patterns were analyzed. For elucidating effects of resin tapping on the climate sensitivity of pine growth, climate-growth relationships and pointer years were studied.Results： We observed that resin tapping positively affects tree growth at breast height, likely as wood formation is concentrated on the living part of the bole（i.e. after tapping there is no growth taking place on the tapping face due to the mechanical damage done to the cambium）. We observed no differences in the climate sensitivity of tapped and non-tapped trees, nor in the occurrence of extreme growth responses.Conclusion： Our results highlight that resin extraction is, apart from inflicting mechanical damage, not altering the sensitivity of Scots pine growth to climatic conditions.展开更多
Shrub expansion into arctic and alpine tundra is one of the prominent vegetation changes currently underway.We studied the expansion of shrub vegetation into high elevation tundra in the Kvarkush Range of the Northern...Shrub expansion into arctic and alpine tundra is one of the prominent vegetation changes currently underway.We studied the expansion of shrub vegetation into high elevation tundra in the Kvarkush Range of the Northern Ural mountains,Russia.Age structure analysis of the dominant shrub Juniperus sibirica Burgsd.seems to support ongoing upslope advance of shrubs,a process particularly active in the second half of the 20 th century.We found a close connection between the expansion of shrub vegetation and the general change in climatic conditions of the cold season(months with mean airtemperature below 0°Сfrom November to March).In general,the greatest influence on the distribution of J.sibirica is exerted by the climate conditions of the beginning(November-January)and the end(March)of the cold season.With increasing elevation,the correlation coefficients between the establishment of J.sibirica shrubs and the precipitation of the beginning of the cold season increased,and reached maximum values at the top elevation level of the study area.However,the upwards shift of J.sibirica into typical mountain tundra does not lead to changes in the ecological structure of vegetation at this stage,but simply a decrease in the area of mountain tundra.展开更多
Background： We compare the climate sensitivity of European beech （Fagus sylvatica L.） in two forest nature reserves in northeastern Germany. The one reserve, Schlossberg, is characterized by shallow chalk soils, wh...Background： We compare the climate sensitivity of European beech （Fagus sylvatica L.） in two forest nature reserves in northeastern Germany. The one reserve, Schlossberg, is characterized by shallow chalk soils, whereas in the other reserve, EIdena, soils are deeper and more developed. Little is known about the drought sensitivity of beech on shallow chalk soils. Methods： We collected increment cores at both research sites and established climate-growth relationships. Inter- tree variability was assessed by employing linear mixed-effect models. Results： We expected to find distinctively higher drought sensitivity at Schlossberg due to limited water availability, but find only marginal differences in growth responses. At both sites, drought is the major climatic factor driving tree growth. Adaptations in tree architecture and an underestimation of the water holding capacity of shallow chalk soils are discussed as possible reasons for not finding more distinct climate responses. In analyzing climate-growth relationships, we specifically focused on growth responses of individual trees but observed only low inter-tree variability at both sites. Evident is a shift in climate response patterns from the first to the second half of the twentieth century with previous-year drought conditions becoming more important than current-year drought. This shift is discussed in relation to a warming trend over that same period, as well as possible trends in masting behavior of beech. Conclusion： The investigated beech trees on the shallow chalk soil are only slightly more drought sensitive than beech trees on the reference site with deeper and more developed soils.展开更多
基金profited from field equipment financed by the Eva Mayr-Stihl Foundation through a grant to EM and MMTa contribution to the Virtual Institute of Integrated Climate and Landscape Evolution Analysis-ICLEA-(grant no.VH-VI-415)the Terrestrial Environmental Observatories project-TERENO-of the Helmholtz Association
文摘Background： In the German Democratic Republic（GDR）, resin tapping in Scots pine（Pinus sylvestris L.） forests was a major economic activity, and resin-tapped stands are frequently found up until this day. In this study, we investigate how the mechanical damage caused by resin tapping affects the growth and climate sensitivity of Scots pine using a dendroecological approach.Methods： Tree-ring samples were collected from resin-tapped and non-tapped trees in two forest areas in northeastern Germany, and tree-growth patterns were analyzed. For elucidating effects of resin tapping on the climate sensitivity of pine growth, climate-growth relationships and pointer years were studied.Results： We observed that resin tapping positively affects tree growth at breast height, likely as wood formation is concentrated on the living part of the bole（i.e. after tapping there is no growth taking place on the tapping face due to the mechanical damage done to the cambium）. We observed no differences in the climate sensitivity of tapped and non-tapped trees, nor in the occurrence of extreme growth responses.Conclusion： Our results highlight that resin extraction is, apart from inflicting mechanical damage, not altering the sensitivity of Scots pine growth to climatic conditions.
基金part of the state assignment of the Institute of Plant and Animal Ecology,Ural Branch of the Russian Academy of Sciences(No.AAAA-A19-119111990097-4No.AAAA-A19-119031890084-6No.AAAA-A19-119111390057-4)。
文摘Shrub expansion into arctic and alpine tundra is one of the prominent vegetation changes currently underway.We studied the expansion of shrub vegetation into high elevation tundra in the Kvarkush Range of the Northern Ural mountains,Russia.Age structure analysis of the dominant shrub Juniperus sibirica Burgsd.seems to support ongoing upslope advance of shrubs,a process particularly active in the second half of the 20 th century.We found a close connection between the expansion of shrub vegetation and the general change in climatic conditions of the cold season(months with mean airtemperature below 0°Сfrom November to March).In general,the greatest influence on the distribution of J.sibirica is exerted by the climate conditions of the beginning(November-January)and the end(March)of the cold season.With increasing elevation,the correlation coefficients between the establishment of J.sibirica shrubs and the precipitation of the beginning of the cold season increased,and reached maximum values at the top elevation level of the study area.However,the upwards shift of J.sibirica into typical mountain tundra does not lead to changes in the ecological structure of vegetation at this stage,but simply a decrease in the area of mountain tundra.
基金support by a research grant of the Eva Mayr-Stihl Foundation MMT and MW are participating researchers of the research training group RESPONSE,funded by the German Research Council(DFG GRK2010)
文摘Background： We compare the climate sensitivity of European beech （Fagus sylvatica L.） in two forest nature reserves in northeastern Germany. The one reserve, Schlossberg, is characterized by shallow chalk soils, whereas in the other reserve, EIdena, soils are deeper and more developed. Little is known about the drought sensitivity of beech on shallow chalk soils. Methods： We collected increment cores at both research sites and established climate-growth relationships. Inter- tree variability was assessed by employing linear mixed-effect models. Results： We expected to find distinctively higher drought sensitivity at Schlossberg due to limited water availability, but find only marginal differences in growth responses. At both sites, drought is the major climatic factor driving tree growth. Adaptations in tree architecture and an underestimation of the water holding capacity of shallow chalk soils are discussed as possible reasons for not finding more distinct climate responses. In analyzing climate-growth relationships, we specifically focused on growth responses of individual trees but observed only low inter-tree variability at both sites. Evident is a shift in climate response patterns from the first to the second half of the twentieth century with previous-year drought conditions becoming more important than current-year drought. This shift is discussed in relation to a warming trend over that same period, as well as possible trends in masting behavior of beech. Conclusion： The investigated beech trees on the shallow chalk soil are only slightly more drought sensitive than beech trees on the reference site with deeper and more developed soils.
