Leaf morphological and stoichiometric characteristics are considered to represent both the interior inheritable characters in the plant and its adaptations to specific exterior environments. Rhododendron agglutinatum,...Leaf morphological and stoichiometric characteristics are considered to represent both the interior inheritable characters in the plant and its adaptations to specific exterior environments. Rhododendron agglutinatum,an evergreen alpine shrub species,occupies a wide range of habitats above timberline in the Miyaluo Natural Reserve,southwestern China. Along an altitudinal gradient ranging from 3700 to 4150 m,we measured leaf morphological characters including leaf dry matter content(LDMC),leaf dry mass per unit area(LMA),and one leaf area(OLA),as well as carbon(C) and nutrient(N,P) contents in leaves of three different age groups(juvenile leaves,mature leaves and senescent leaves). We also calculated the stoichiometric relationships among carbon and nutrients(C/N,C/P and N/P). Results showed thatboth age and altitude affected the leaf morphological and stoichiometric properties of R. agglutinatum. Mature leaves possessed the highest LDMC,LMA and C contents both on a dry mass basis and on a unit area basis. Younger leaves possessed higher contents of nutrients. OLA as well as ratios between carbon and nutrients(C/N,C/P) increased with ages. Juvenile leaves possessed lowest ratio between nitrogen and phosphorus. In juvenile leaves,nutrients increased with altitudinal elevation,whereas other traits decreased. In mature leaves,nutrients and their ratios with carbon showed consistent trends with juvenile leaves along increasing altitude,whereas LMA and carbon on a unit area basis showed opposite trends with juvenile leaves along increasing altitude. In senescent leaves,only content of phosphorus on a unit area basis and N/P were found linearly correlated with altitude. Our results demonstrated a clear pattern of nutrient distribution with aging process inleaves and indicated that a high possibility of N limitation in this region. We also concluded that younger leaves could be more sensitive to climate changes due to a greater altitudinal influence on the leaf traits in younger leaves than those in elder leaves.展开更多
Understanding the trade-offs among ecosystem services(ESs)at multiple scales is a key challenge to effective environmental management.However,the scale effect of ESs trade-offs in the Qinghai-Tibetan Plateau(QTP)has r...Understanding the trade-offs among ecosystem services(ESs)at multiple scales is a key challenge to effective environmental management.However,the scale effect of ESs trade-offs in the Qinghai-Tibetan Plateau(QTP)has received little attention.This study investigated the scale effects of ESs trade-offs in Bailongjiang Watershed(BLJW),a typical transitional ecotone from the Loess Plateau to the Tibetan Plateau with multiple ESs,intensive human activities and frequent geological disasters in the Eastern Margin of the QTP,China.Four key ESs including food supply(FS),soil conservation(SC),water conservation(WC),and habitat quality(HQ)in BLJW in 1990,2002,and 2016 were mapped to analyze the scale effects at the watershed,county,and township scales.The results indicated varying scale-related temporal and spatial relationships among FS,SC,WC,and HQ.The trade-offs between FS-SC and FS-WC initially increased and then decreased during 1990-2002 and 2002-2016,respectively,while the trade-offs between SC-WC,SC-HQ,HQ-WC,and HQ-FS first decreased and then increased at the same period.The magnitudes of the trade-offs among the four ESs are in the order of watershed scale>township scale>county scale.Among the major land-use types in BLJW,the trade-offs between WC-FS and between HQ-FS in farmland and grassland were higher than those of other land uses.There is a strong trade-off between SC-HQ in forestland and a weak trade-off between SC-WC in farmland and grassland.The trade-offs between the six ESs pairs varied and were scale-dependent mainly due to spatial heterogeneity in the landscape and in human activities.Understanding the ESs trade-offs at the watershed,county,and township scales provides a scientific basis for the formulation of environmental management strategies at appropriate spatial scales.At the BLJW watershed scale,more attention should be paid on farmland and grassland planning and its management,also,forestland should be enlarged if possible.At the county and township scales,land consolidation and planning should be paid more attention to develop ecological agricultural tourism and multi-functional landscapes for strategic spatial planning and integrated watershed management.展开更多
The Pi(Spleen)is responsible for the formation and transportation,and it is in the center.It is the source of qi and blood generation and transformation,so it has an essential position.If the qi and blood are biochemi...The Pi(Spleen)is responsible for the formation and transportation,and it is in the center.It is the source of qi and blood generation and transformation,so it has an essential position.If the qi and blood are biochemically passive,the functions of the human body will age prematurely.Mitochondria are for energy synthesis and have always been a hot topic in modern medical research.Many of their functions are similar to those of the Pi in Chinese medicine.In Chinese medicine,strengthening the Pi is to enhance the Pi’s ability to transport and transform,and to speed up the Pi,which is similar to the ability of mitochondria to maintain the ability to remove damaged cells.This can speed up the body’s ability to absorb nutrients and delay aging.展开更多
基金supported by the National Natural Science Foundation of China (No.41071039)National Key Research and Development Program (No.2016YFC0502100)
文摘Leaf morphological and stoichiometric characteristics are considered to represent both the interior inheritable characters in the plant and its adaptations to specific exterior environments. Rhododendron agglutinatum,an evergreen alpine shrub species,occupies a wide range of habitats above timberline in the Miyaluo Natural Reserve,southwestern China. Along an altitudinal gradient ranging from 3700 to 4150 m,we measured leaf morphological characters including leaf dry matter content(LDMC),leaf dry mass per unit area(LMA),and one leaf area(OLA),as well as carbon(C) and nutrient(N,P) contents in leaves of three different age groups(juvenile leaves,mature leaves and senescent leaves). We also calculated the stoichiometric relationships among carbon and nutrients(C/N,C/P and N/P). Results showed thatboth age and altitude affected the leaf morphological and stoichiometric properties of R. agglutinatum. Mature leaves possessed the highest LDMC,LMA and C contents both on a dry mass basis and on a unit area basis. Younger leaves possessed higher contents of nutrients. OLA as well as ratios between carbon and nutrients(C/N,C/P) increased with ages. Juvenile leaves possessed lowest ratio between nitrogen and phosphorus. In juvenile leaves,nutrients increased with altitudinal elevation,whereas other traits decreased. In mature leaves,nutrients and their ratios with carbon showed consistent trends with juvenile leaves along increasing altitude,whereas LMA and carbon on a unit area basis showed opposite trends with juvenile leaves along increasing altitude. In senescent leaves,only content of phosphorus on a unit area basis and N/P were found linearly correlated with altitude. Our results demonstrated a clear pattern of nutrient distribution with aging process inleaves and indicated that a high possibility of N limitation in this region. We also concluded that younger leaves could be more sensitive to climate changes due to a greater altitudinal influence on the leaf traits in younger leaves than those in elder leaves.
基金This work was supported by the National Natural Science Foundation of China(Grant No.41771196)the Second Tibetan Plateau Scientific Expedition and Research(No.2019QZKK0603)National Key R&D Program of China(No.2016YFC0501701).
文摘Understanding the trade-offs among ecosystem services(ESs)at multiple scales is a key challenge to effective environmental management.However,the scale effect of ESs trade-offs in the Qinghai-Tibetan Plateau(QTP)has received little attention.This study investigated the scale effects of ESs trade-offs in Bailongjiang Watershed(BLJW),a typical transitional ecotone from the Loess Plateau to the Tibetan Plateau with multiple ESs,intensive human activities and frequent geological disasters in the Eastern Margin of the QTP,China.Four key ESs including food supply(FS),soil conservation(SC),water conservation(WC),and habitat quality(HQ)in BLJW in 1990,2002,and 2016 were mapped to analyze the scale effects at the watershed,county,and township scales.The results indicated varying scale-related temporal and spatial relationships among FS,SC,WC,and HQ.The trade-offs between FS-SC and FS-WC initially increased and then decreased during 1990-2002 and 2002-2016,respectively,while the trade-offs between SC-WC,SC-HQ,HQ-WC,and HQ-FS first decreased and then increased at the same period.The magnitudes of the trade-offs among the four ESs are in the order of watershed scale>township scale>county scale.Among the major land-use types in BLJW,the trade-offs between WC-FS and between HQ-FS in farmland and grassland were higher than those of other land uses.There is a strong trade-off between SC-HQ in forestland and a weak trade-off between SC-WC in farmland and grassland.The trade-offs between the six ESs pairs varied and were scale-dependent mainly due to spatial heterogeneity in the landscape and in human activities.Understanding the ESs trade-offs at the watershed,county,and township scales provides a scientific basis for the formulation of environmental management strategies at appropriate spatial scales.At the BLJW watershed scale,more attention should be paid on farmland and grassland planning and its management,also,forestland should be enlarged if possible.At the county and township scales,land consolidation and planning should be paid more attention to develop ecological agricultural tourism and multi-functional landscapes for strategic spatial planning and integrated watershed management.
基金The National Key Research and Development Plan Modernization Research Project of Traditional Chinese Medicine(2019YFC1708502)。
文摘The Pi(Spleen)is responsible for the formation and transportation,and it is in the center.It is the source of qi and blood generation and transformation,so it has an essential position.If the qi and blood are biochemically passive,the functions of the human body will age prematurely.Mitochondria are for energy synthesis and have always been a hot topic in modern medical research.Many of their functions are similar to those of the Pi in Chinese medicine.In Chinese medicine,strengthening the Pi is to enhance the Pi’s ability to transport and transform,and to speed up the Pi,which is similar to the ability of mitochondria to maintain the ability to remove damaged cells.This can speed up the body’s ability to absorb nutrients and delay aging.
