对陆上生态体系而言,植物生理季节性变化是衡量其对气候转变反响的关键度量尺度,尤其对全球气温上升现象极为敏感的高纬度与高海拔地带的植物生理季节性。本研究借助MOD13A1卫星遥感资料,叠加温度与降水数据,剖析2000~2021年间蒙古国西...对陆上生态体系而言,植物生理季节性变化是衡量其对气候转变反响的关键度量尺度,尤其对全球气温上升现象极为敏感的高纬度与高海拔地带的植物生理季节性。本研究借助MOD13A1卫星遥感资料,叠加温度与降水数据,剖析2000~2021年间蒙古国西部地区植被生长季始期(Start of growing season,SOS)、生长季长度(Length of growing season,LOS)以及生长季末期(End of growing season,EOS)的时空变化特征和海拔依赖性变化机制。结果如下:(1)蒙古国西部地区的SOS主要集中在第90~125 d,近22 a来SOS呈微弱的提前趋势,提前幅度为0.23 d/a。(2)植被物候与气象要素的关系表明,2月的气温和降水与SOS显著负相关(P<0.05),1月的气温和降水与SOS显著正相关(P<0.05),而EOS主要受8月气温和降水的影响。(3)草甸草原和典型草原SOS主要受降水影响,高山草原、荒漠草原以及针叶林的SOS主要受气温影响,所有植被类型的EOS对温度的响应更大。总的来说,研究区植被物候与气候因子表现出季节性的差异,响应规律复杂。展开更多
为了明确绣球〔Hydrangea macrophylla(Thunb.)Ser.〕品种的耐寒性及筛选耐寒性评价主要指标,对40个绣球品种的低温半致死温度(LT_(50))进行比较和耐寒性分级,在此基础上,对5℃、0℃、-5℃、-10℃、-15℃、-20℃下耐寒品种‘小町’(‘Ko...为了明确绣球〔Hydrangea macrophylla(Thunb.)Ser.〕品种的耐寒性及筛选耐寒性评价主要指标,对40个绣球品种的低温半致死温度(LT_(50))进行比较和耐寒性分级,在此基础上,对5℃、0℃、-5℃、-10℃、-15℃、-20℃下耐寒品种‘小町’(‘Komachi’)、‘佳澄’(‘Kasumi’)、‘无尽夏’(‘Endless Summer’)和不耐寒品种‘甜蜜幻想’(‘Sweet Fantasy’)、‘灵感’(‘Inspiration’)、‘你我的情感’(‘You and Me Feelings’)叶的抗氧化酶活性及丙二醛(MDA)和渗透调节物质含量进行比较,并对这些耐寒指标进行相关性分析和主成分分析。结果表明:供试绣球品种LT 50的波动较大,变化范围为-36.68℃~-1.87℃,其中,‘小町’的LT_(50)最低,‘佳澄’、‘平瓣’(‘Flat’)、‘蒂亚娜’(‘Tijana’)、‘塞尔玛’(‘Selma’)、‘含羞叶’(‘Elbtal’)、‘花手鞠’(‘Stockings’)、‘蓝色多瑙河’(‘Blue Danube’)和‘无尽夏’的LT_(50)均低于-20℃。40个绣球品种的耐寒性被分成不耐寒、较耐寒、耐寒和强耐寒4个等级,分别包含13、18、8和1个品种。6个代表品种的过氧化氢酶(CAT)、多酚氧化酶(PPO)和超氧化物歧化酶活性及MDA、脯氨酸(Pro)、可溶性蛋白质(SP)和可溶性糖含量随温度降低基本呈先升高后降低的变化趋势。相关性分析结果表明PPO活性和Pro含量与LT_(50)呈极显著(P<0.01)负相关。主成分分析结果表明:前4个主成分的累计贡献率为81.212%,说明这4个主成分基本能够反映绣球品种的耐寒性;PPO活性、CAT活性、Pro含量和SP含量的负荷量绝对值分别在第1、第2、第3和第4主成分中最高。研究结果显示:供试绣球品种间的耐寒性差异较大,‘小町’等9个品种的耐寒性较强,能够在冬季温度偏低地区露天栽培,并可作为绣球耐寒品种选育的亲本。PPO活性、CAT活性、Pro含量和SP含量为绣球耐寒性评价的主要指标,尤其是PPO活性和Pro含量。展开更多
The basic concept of phytosociology is crucial for the assessment of species composition and dynamic ecological succession of forests supporting ecological services,functions,disturbance,and resilience that lead to th...The basic concept of phytosociology is crucial for the assessment of species composition and dynamic ecological succession of forests supporting ecological services,functions,disturbance,and resilience that lead to the development of integrated areas such as ecological niche modeling and contribute to identifying the valuable bio-indicators which can be used in framing conservation and management planning.B.utilis is one of the most dominant tree species of treeline ecotone in the Himalayan Region.The species is also considered as indicator species for monitoring the past and recent climate change impact.The current study was carried out in the natural populations of B.utilis from the sub-alpine zone of North-western Indian Himalaya.The birch dominated forest harbors a total of 305 plant species comprising Angiosperms(51 families,160 genera and 277 species),Gymnosperms(03 families,05 genera and 07 species)and Pteridophytes(07 families,11 genera and 21 species)with Asteraceae,Ranunculaceae and Rosaceae as dominant family.Birch forests are found dominant in shady moist habitat and North West aspect.Geographical characteristics,anthropogenic and developmental activities affect the population structure of B.utilis and associated species.However,the species has fair regeneration status in the study area.The acidic nature of soil pH and spatial variation in edaphic characteristics may be due to geographical differences,rooting patterns and litter accumulation of below and above-ground vegetation.Biomass estimation of a representative population of B.utilis from each site showed that TAGBD,TCD and TBD were found maximum in ST3(Hamta Pass II site).The CCA analysis determined that environmental variables such as altitude,organic matter,available phosphorous,organic carbon,available nitrogen,and electrical conductivity played a significant role in determining tree species composition and distribution in B.utilis dominated forests.展开更多
Climate change poses a serious long-term threat to biodiversity.To effectively reduce biodiversity loss,conservationists need to have a thorough understanding of the preferred habitats of species and the variables tha...Climate change poses a serious long-term threat to biodiversity.To effectively reduce biodiversity loss,conservationists need to have a thorough understanding of the preferred habitats of species and the variables that affect their distribution.Therefore,predicting the impact of climate change on speciesappropriate habitats may help mitigate the potential threats to biodiversity distribution.Xerophyta,a monocotyledonous genus of the family Velloziaceae is native to mainland Africa,Madagascar,and the Arabian Peninsula.The key drivers of Xerophyta habitat distribution and preference are unknown.Using 308 species occurrence data and eight environmental variables,the MaxEnt model was used to determine the potential distribution of six Xerophyta species in Africa under past,current and future climate change scenarios.The results showed that the models had a good predictive ability(Area Under the Curve and True Skill Statistics values for all SDMs were more than 0.902),indicating high accuracy in forecasting the potential geographic distribution of Xerophyta species.The main bioclimatic variables that impacted potential distributions of most Xerophyta species were mean temperature of the driest quarter(Bio9)and precipitation of the warmest quarter(Bio18).According to our models,tropical Africa has zones of moderate and high suitability for Xerophyta taxa,which is consistent with the majority of documented species localities.The habitat suitability of the existing range of the Xerophyta species varied based on the climate scenario,with most species experiencing a range loss greater than the range gain regardless of the climate scenario.The projected spatiotemporal patterns of Xerophyta species help guide recommendations for conservation efforts.展开更多
文摘对陆上生态体系而言,植物生理季节性变化是衡量其对气候转变反响的关键度量尺度,尤其对全球气温上升现象极为敏感的高纬度与高海拔地带的植物生理季节性。本研究借助MOD13A1卫星遥感资料,叠加温度与降水数据,剖析2000~2021年间蒙古国西部地区植被生长季始期(Start of growing season,SOS)、生长季长度(Length of growing season,LOS)以及生长季末期(End of growing season,EOS)的时空变化特征和海拔依赖性变化机制。结果如下:(1)蒙古国西部地区的SOS主要集中在第90~125 d,近22 a来SOS呈微弱的提前趋势,提前幅度为0.23 d/a。(2)植被物候与气象要素的关系表明,2月的气温和降水与SOS显著负相关(P<0.05),1月的气温和降水与SOS显著正相关(P<0.05),而EOS主要受8月气温和降水的影响。(3)草甸草原和典型草原SOS主要受降水影响,高山草原、荒漠草原以及针叶林的SOS主要受气温影响,所有植被类型的EOS对温度的响应更大。总的来说,研究区植被物候与气候因子表现出季节性的差异,响应规律复杂。
文摘为了明确绣球〔Hydrangea macrophylla(Thunb.)Ser.〕品种的耐寒性及筛选耐寒性评价主要指标,对40个绣球品种的低温半致死温度(LT_(50))进行比较和耐寒性分级,在此基础上,对5℃、0℃、-5℃、-10℃、-15℃、-20℃下耐寒品种‘小町’(‘Komachi’)、‘佳澄’(‘Kasumi’)、‘无尽夏’(‘Endless Summer’)和不耐寒品种‘甜蜜幻想’(‘Sweet Fantasy’)、‘灵感’(‘Inspiration’)、‘你我的情感’(‘You and Me Feelings’)叶的抗氧化酶活性及丙二醛(MDA)和渗透调节物质含量进行比较,并对这些耐寒指标进行相关性分析和主成分分析。结果表明:供试绣球品种LT 50的波动较大,变化范围为-36.68℃~-1.87℃,其中,‘小町’的LT_(50)最低,‘佳澄’、‘平瓣’(‘Flat’)、‘蒂亚娜’(‘Tijana’)、‘塞尔玛’(‘Selma’)、‘含羞叶’(‘Elbtal’)、‘花手鞠’(‘Stockings’)、‘蓝色多瑙河’(‘Blue Danube’)和‘无尽夏’的LT_(50)均低于-20℃。40个绣球品种的耐寒性被分成不耐寒、较耐寒、耐寒和强耐寒4个等级,分别包含13、18、8和1个品种。6个代表品种的过氧化氢酶(CAT)、多酚氧化酶(PPO)和超氧化物歧化酶活性及MDA、脯氨酸(Pro)、可溶性蛋白质(SP)和可溶性糖含量随温度降低基本呈先升高后降低的变化趋势。相关性分析结果表明PPO活性和Pro含量与LT_(50)呈极显著(P<0.01)负相关。主成分分析结果表明:前4个主成分的累计贡献率为81.212%,说明这4个主成分基本能够反映绣球品种的耐寒性;PPO活性、CAT活性、Pro含量和SP含量的负荷量绝对值分别在第1、第2、第3和第4主成分中最高。研究结果显示:供试绣球品种间的耐寒性差异较大,‘小町’等9个品种的耐寒性较强,能够在冬季温度偏低地区露天栽培,并可作为绣球耐寒品种选育的亲本。PPO活性、CAT活性、Pro含量和SP含量为绣球耐寒性评价的主要指标,尤其是PPO活性和Pro含量。
基金the GBPI Mountain Division-Himalayan Research Fellowship for financial support
文摘The basic concept of phytosociology is crucial for the assessment of species composition and dynamic ecological succession of forests supporting ecological services,functions,disturbance,and resilience that lead to the development of integrated areas such as ecological niche modeling and contribute to identifying the valuable bio-indicators which can be used in framing conservation and management planning.B.utilis is one of the most dominant tree species of treeline ecotone in the Himalayan Region.The species is also considered as indicator species for monitoring the past and recent climate change impact.The current study was carried out in the natural populations of B.utilis from the sub-alpine zone of North-western Indian Himalaya.The birch dominated forest harbors a total of 305 plant species comprising Angiosperms(51 families,160 genera and 277 species),Gymnosperms(03 families,05 genera and 07 species)and Pteridophytes(07 families,11 genera and 21 species)with Asteraceae,Ranunculaceae and Rosaceae as dominant family.Birch forests are found dominant in shady moist habitat and North West aspect.Geographical characteristics,anthropogenic and developmental activities affect the population structure of B.utilis and associated species.However,the species has fair regeneration status in the study area.The acidic nature of soil pH and spatial variation in edaphic characteristics may be due to geographical differences,rooting patterns and litter accumulation of below and above-ground vegetation.Biomass estimation of a representative population of B.utilis from each site showed that TAGBD,TCD and TBD were found maximum in ST3(Hamta Pass II site).The CCA analysis determined that environmental variables such as altitude,organic matter,available phosphorous,organic carbon,available nitrogen,and electrical conductivity played a significant role in determining tree species composition and distribution in B.utilis dominated forests.
基金supported by grants from the International Partnership Program of Chinese Academy of Sciences (151853KYSB20190027)Sino-Africa Joint Research Center, CAS (SAJC202101)The ANSO Scholarship for Young Talents, PhD Fellowship Program University of Chinese Academy of Sciences, China
文摘Climate change poses a serious long-term threat to biodiversity.To effectively reduce biodiversity loss,conservationists need to have a thorough understanding of the preferred habitats of species and the variables that affect their distribution.Therefore,predicting the impact of climate change on speciesappropriate habitats may help mitigate the potential threats to biodiversity distribution.Xerophyta,a monocotyledonous genus of the family Velloziaceae is native to mainland Africa,Madagascar,and the Arabian Peninsula.The key drivers of Xerophyta habitat distribution and preference are unknown.Using 308 species occurrence data and eight environmental variables,the MaxEnt model was used to determine the potential distribution of six Xerophyta species in Africa under past,current and future climate change scenarios.The results showed that the models had a good predictive ability(Area Under the Curve and True Skill Statistics values for all SDMs were more than 0.902),indicating high accuracy in forecasting the potential geographic distribution of Xerophyta species.The main bioclimatic variables that impacted potential distributions of most Xerophyta species were mean temperature of the driest quarter(Bio9)and precipitation of the warmest quarter(Bio18).According to our models,tropical Africa has zones of moderate and high suitability for Xerophyta taxa,which is consistent with the majority of documented species localities.The habitat suitability of the existing range of the Xerophyta species varied based on the climate scenario,with most species experiencing a range loss greater than the range gain regardless of the climate scenario.The projected spatiotemporal patterns of Xerophyta species help guide recommendations for conservation efforts.
