When facilitating other species and sustaining plant community structures and biodiversity,alpine cushion plants simultaneously experience negative feedback effects from surrounding vegetation.However,the impact of su...When facilitating other species and sustaining plant community structures and biodiversity,alpine cushion plants simultaneously experience negative feedback effects from surrounding vegetation.However,the impact of surrounding vegetation on cushion dynamics remains poorly understood,particularly in terms of allelopathic potentials.To investigate the allelopathic potentials of surrounding vegetation on seedling establishment of the typical cushion plant Arenaria polytrichoides Edgew.along an elevational gradient,we extracted potential allelopathic compounds and tested their impacts on seed germination and seedling growth of A.polytrichoides.In addition,exclusion experiments using activated carbon were conducted to further elucidate these effects.Our results demonstrate that surrounding vegetation exhibits certain allelopathic potentials on A.polytrichoides seedling establishment,with variations observed based on elevation,source and concentration of allelopathy compounds,as well as growing season.Specifcally,low-elevation vegetation exerts pronounced suppression on seedling establishment.Conversely,higher-elevation vegetation generally shows no effect on seed germination but stimulates seedling growth through allelopathy mechanisms.Moreover,aboveground vegetation predominantly inhibits both seed germination and seedling growth in low-elevation communities;however,the effects of belowground vegetation depend on elevation and extract concentration levels.The identifed allelopathic potentials of surrounding vegetation signifcantly infuence the population dynamics of cushion A.polytrichoides by potentially accelerating population degeneration in lower-elevation communities while ensuring consistent population recruitment and expansion in higher-elevation communities.展开更多
Aims Germination is the earliest life-history transition of a plant species.It determines the ecological breadth and geographic ranges of a species and has major effects on its invasion potential.The largest spread of...Aims Germination is the earliest life-history transition of a plant species.It determines the ecological breadth and geographic ranges of a species and has major effects on its invasion potential.The largest spread of the invasive salt-marsh cordgrass Spartina alterniflora in China,where it extends to latitudes lower than its native range in North America,provides an opportunity to examine germination trait variation across latitudes within and among its invasive and native ranges.Methods We studied seed germination traits of S.alterniflora using seeds collected from 10 locations across latitudes in its invasive range(China,20°–40°N)and 16 locations across latitudes in its native range(USA,27°–43°N)in growth chambers with 0 PSU sterilized distilled water.We further evaluated how climate and tide range in the original locations influenced germination traits.Important Findings Native populations showed higher(~10%)germination percentage and significantly higher(~20%)germination index than invasive populations did,but invasive populations germinated significantly earlier(~3 days)than native populations.Germination percentage and germination index increased with latitude in the invasive range but decreased with latitude in the native range.The mean germination time decreased with latitude in the invasive range and paralleled that in the native range.Germination percentage and germination index were negatively correlated with mean daily temperature(Tmean),mean daily maximum temperature(Tmax)and mean daily minimum temperature(Tmin),and inversely correlated with Tmean,Tmax and Tmin in the native range.However,the mean germination time was positively correlated with Tmean,Tmax and Tmean in both ranges.Our results demonstrate that invasive and native populations have evolved different latitudinal clines in germination percentage and index,but the mean germination time of the invasive population mirrored the latitudinal cline observed in the native range,suggesting that germination strategy across latitudes may change during invasion process.展开更多
基金supported by the Second Tibetan Plateau Scientifc Expedition and Research Program(2019QZKK0502)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA20050203)+1 种基金the Yunnan Applied Basic Research Project(202001AT070060,202301AS070058)the Young Academic and Technical Leader Raising Foundation of Yunnan Province(202205AC160053)。
文摘When facilitating other species and sustaining plant community structures and biodiversity,alpine cushion plants simultaneously experience negative feedback effects from surrounding vegetation.However,the impact of surrounding vegetation on cushion dynamics remains poorly understood,particularly in terms of allelopathic potentials.To investigate the allelopathic potentials of surrounding vegetation on seedling establishment of the typical cushion plant Arenaria polytrichoides Edgew.along an elevational gradient,we extracted potential allelopathic compounds and tested their impacts on seed germination and seedling growth of A.polytrichoides.In addition,exclusion experiments using activated carbon were conducted to further elucidate these effects.Our results demonstrate that surrounding vegetation exhibits certain allelopathic potentials on A.polytrichoides seedling establishment,with variations observed based on elevation,source and concentration of allelopathy compounds,as well as growing season.Specifcally,low-elevation vegetation exerts pronounced suppression on seedling establishment.Conversely,higher-elevation vegetation generally shows no effect on seed germination but stimulates seedling growth through allelopathy mechanisms.Moreover,aboveground vegetation predominantly inhibits both seed germination and seedling growth in low-elevation communities;however,the effects of belowground vegetation depend on elevation and extract concentration levels.The identifed allelopathic potentials of surrounding vegetation signifcantly infuence the population dynamics of cushion A.polytrichoides by potentially accelerating population degeneration in lower-elevation communities while ensuring consistent population recruitment and expansion in higher-elevation communities.
基金the National Natural Science Foundation of China(31770464,31470485,41276078,32001234)China Postdoctoral Science Foundation(2019M662239,2020T130363).
文摘Aims Germination is the earliest life-history transition of a plant species.It determines the ecological breadth and geographic ranges of a species and has major effects on its invasion potential.The largest spread of the invasive salt-marsh cordgrass Spartina alterniflora in China,where it extends to latitudes lower than its native range in North America,provides an opportunity to examine germination trait variation across latitudes within and among its invasive and native ranges.Methods We studied seed germination traits of S.alterniflora using seeds collected from 10 locations across latitudes in its invasive range(China,20°–40°N)and 16 locations across latitudes in its native range(USA,27°–43°N)in growth chambers with 0 PSU sterilized distilled water.We further evaluated how climate and tide range in the original locations influenced germination traits.Important Findings Native populations showed higher(~10%)germination percentage and significantly higher(~20%)germination index than invasive populations did,but invasive populations germinated significantly earlier(~3 days)than native populations.Germination percentage and germination index increased with latitude in the invasive range but decreased with latitude in the native range.The mean germination time decreased with latitude in the invasive range and paralleled that in the native range.Germination percentage and germination index were negatively correlated with mean daily temperature(Tmean),mean daily maximum temperature(Tmax)and mean daily minimum temperature(Tmin),and inversely correlated with Tmean,Tmax and Tmin in the native range.However,the mean germination time was positively correlated with Tmean,Tmax and Tmean in both ranges.Our results demonstrate that invasive and native populations have evolved different latitudinal clines in germination percentage and index,but the mean germination time of the invasive population mirrored the latitudinal cline observed in the native range,suggesting that germination strategy across latitudes may change during invasion process.
