Background Given the ubiquitous nature of mycorrhizal symbioses,different symbiotic fungi have obvious differences in structure and function,which may affect associated tree aboveground and belowground C allocation dy...Background Given the ubiquitous nature of mycorrhizal symbioses,different symbiotic fungi have obvious differences in structure and function,which may affect associated tree aboveground and belowground C allocation dynamics.However,the mechanisms underlying tree aboveground and belowground C allocation and its response to symbiotic mycorrhizal types and other factors(e.g.,resource availability)remain poorly understood.Results We used forest inventory data to explore the potential mechanism of tree aboveground and belowground C allocation patterns in Northeast China.Our results showed that tree-fungal symbioses were related to the patterns of tree C allocation.The ratio of aboveground to belowground C pool was significantly higher in ectomycorrhizal(EM)-associated trees than that in arbuscular mycorrhizal(AM)-associated trees.Symbiotic mycorrhizal types were associ-ated with the responses of tree aboveground and belowground C allocation to different factors,such as mean annual precipitation(MAP)and mean annual temperature(MAT).Almost all factors significantly increased aboveground C allocation in AM-associated trees but significantly decreased it in EM-associated trees.Moreover,after controlling the other factors,the effects of climate factors(MAT and MAP)on the C allocation of AM-and EM-associated trees were similar.Increases in MAT and MAP significantly increased belowground and aboveground C allocation,respectively.Conclusions Our results demonstrate symbiotic mycorrhizal types play an important role in controlling tree aboveground and belowground C allocation and dynamics.展开更多
A widely accepted standpoint contends that plant growth near the cold edge of the species range,such as treelines,does not depend on the annual temperature seasonality(i.e.difference between maximum and minimum temper...A widely accepted standpoint contends that plant growth near the cold edge of the species range,such as treelines,does not depend on the annual temperature seasonality(i.e.difference between maximum and minimum temperature values) but rather on the warmth of summer season.In contrast to this expectation,we show that the growth of treeline Norway spruce(Picea abies) is well explained by temperature seasonality as a single climatic determinant.To do so,the tree-ring data of spruce trees growing on alpine treeline in Lapland was compared with long climate records.Biennial time-series of temperature seasonality capture both the decadal and abrupt growth fluctuations with a correlation coefficient of r = 0.601.We also show that the archetypal association between summer temperature and treeline tree growth may in fact be by far a more complex relationship than previously thought.Spruce growth appears responsive to lateJune(r = 0.494) and mid-July(r = 0.310) temperatures but unresponsive to temperatures during the early July,that is,during the grand period of the tracheid formation.Climatic warming may enhance the treeline spruce growth unless the warming is concentrated on unresponsive interval in the midst of the growing season.Water relations did not play significant role as agents of P.abies growth.展开更多
基金supported by grants from the National Natural Science Foundation of China(42230703,41773075,41575137).
文摘Background Given the ubiquitous nature of mycorrhizal symbioses,different symbiotic fungi have obvious differences in structure and function,which may affect associated tree aboveground and belowground C allocation dynamics.However,the mechanisms underlying tree aboveground and belowground C allocation and its response to symbiotic mycorrhizal types and other factors(e.g.,resource availability)remain poorly understood.Results We used forest inventory data to explore the potential mechanism of tree aboveground and belowground C allocation patterns in Northeast China.Our results showed that tree-fungal symbioses were related to the patterns of tree C allocation.The ratio of aboveground to belowground C pool was significantly higher in ectomycorrhizal(EM)-associated trees than that in arbuscular mycorrhizal(AM)-associated trees.Symbiotic mycorrhizal types were associ-ated with the responses of tree aboveground and belowground C allocation to different factors,such as mean annual precipitation(MAP)and mean annual temperature(MAT).Almost all factors significantly increased aboveground C allocation in AM-associated trees but significantly decreased it in EM-associated trees.Moreover,after controlling the other factors,the effects of climate factors(MAT and MAP)on the C allocation of AM-and EM-associated trees were similar.Increases in MAT and MAP significantly increased belowground and aboveground C allocation,respectively.Conclusions Our results demonstrate symbiotic mycorrhizal types play an important role in controlling tree aboveground and belowground C allocation and dynamics.
文摘A widely accepted standpoint contends that plant growth near the cold edge of the species range,such as treelines,does not depend on the annual temperature seasonality(i.e.difference between maximum and minimum temperature values) but rather on the warmth of summer season.In contrast to this expectation,we show that the growth of treeline Norway spruce(Picea abies) is well explained by temperature seasonality as a single climatic determinant.To do so,the tree-ring data of spruce trees growing on alpine treeline in Lapland was compared with long climate records.Biennial time-series of temperature seasonality capture both the decadal and abrupt growth fluctuations with a correlation coefficient of r = 0.601.We also show that the archetypal association between summer temperature and treeline tree growth may in fact be by far a more complex relationship than previously thought.Spruce growth appears responsive to lateJune(r = 0.494) and mid-July(r = 0.310) temperatures but unresponsive to temperatures during the early July,that is,during the grand period of the tracheid formation.Climatic warming may enhance the treeline spruce growth unless the warming is concentrated on unresponsive interval in the midst of the growing season.Water relations did not play significant role as agents of P.abies growth.
