Pelagic appendicularians,known for their rapid bloom capability,are important secondary producers and play essential roles in marine ecosystems.To assess the environmental adaptation of the most common appendicularian...Pelagic appendicularians,known for their rapid bloom capability,are important secondary producers and play essential roles in marine ecosystems.To assess the environmental adaptation of the most common appendicularian species Oikopleura dioica in Jiaozhou Bay,Shandong,China,its annual variations in abundance and body size were investigated monthly at 12 stations in 2011,and the relationship between somatic growth and gonadal development was compared with previously published laboratory data.Oikopleura dioica exhibited distinct seasonal abundance patterns,peaking in summer and autumn,particularly in the inner bay,reflecting its adaptation to the eutrophic conditions and high food availability.Compared to laboratory results,O.dioica in Jiaozhou Bay exhibited shorter body lengths,smaller gonad volumes,and earlier maturation at reduced body sizes,despite high natural chlorophyll-a concentration,suggesting that factors beyond food availability,such as resource competition and environmental stressors,may limit its growth in natural settings.Correlation analysis indicated that the somatic growth of natural O.dioica was primarily influenced by temperature,while gonadal development was related to chlorophyll-a concentration,and its population abundance was linked to food availability and the abundance of other zooplankton,such as copepods and jellyfish.It was suggested that the growth and recruitment of O.dioica were constrained by resource limitations in natural environments,further exacerbated by interactions with other zooplankton,including predation and competition.This study provides valuable data on the mechanisms underlying bio-environmental interactions and their spatiotemporal variations,offering critical insights into the ecological roles of appendicularians in marine ecosystems.展开更多
Nutrients play a crucial role in sustaining marine ecosystems and supporting mariculture,especially in seaweed aquaculture.Currently,seaweed farming,such as kelp cultivation,is entirely dependent on the natural supply...Nutrients play a crucial role in sustaining marine ecosystems and supporting mariculture,especially in seaweed aquaculture.Currently,seaweed farming,such as kelp cultivation,is entirely dependent on the natural supply of nutrients.Sanggou Bay in Shandong Peninsula,Yellow Sea,is renowned for its 60-year history of kelp cultivation;however,it is recently facing an increasing demand for nitrogen and phosphorus due to the expansion in aquaculture scale and production.There is no doubt that nutrient addition can enhance and sustain the production,but it is crucial to understand its effect on kelp growth under current nutrients condition and the potential ecological risks.Our in-field nutrient enrichment experiments show that nitrogen and phosphorus additions promoted the kelp biomass during the early growth stages,and have no adverse effects on phytoplankton or seawater nutrient levels throughout the experiment.From a long-term perspective,increasing nutrient supply appears to be an essential strategy for sustaining the aquaculture of kelp.展开更多
Against the background of rapid urbanization and the“Dual Carbon”goals,analyzing the impact mechanisms of land use change on carbon metabolism is crucial for regional sustainable development.Taking the Guangdong-Hon...Against the background of rapid urbanization and the“Dual Carbon”goals,analyzing the impact mechanisms of land use change on carbon metabolism is crucial for regional sustainable development.Taking the Guangdong-Hong Kong-Macao Greater Bay Area(GBA)as the study area,we integrate energy consumption data and the Forest Carbon Sequestration(FCS)model to clarify the land use carbon metabolism status based on Ecological Network Analysis(ENA),and systematically analyze the spatiotemporal evolution patterns of urban land use carbon metabolism,interactions between land types,as well as its driving mechanisms in the GBA from 2000 to 2023.The results show that:(1)Over the past two decades,land use changes have exhibited a significant characteristic of“natural land retreat and construction land expansion”,with areas of cropland,forest,and waterbody shrank by 16%,4%,and 4% respectively,while urban land and industrial land increased by 50%and 438%respectively;76% of the reclaimed land was transferred to construction land.(2)The imbalance of carbon metabolism was jointly affected by land use patterns and land use change processes:carbon emissions from energy consumption surged by 116%,while land carbon sequestration capacity decreased by 12%;in most periods,the negative carbon flow from land use change exceeded positive flows,with both showing sharp fluctuations.(3)Construction land in various cities dominated the carbon flow network through control or exploitation relationships,and the mutual transfer between industrial land and cropland is the primary driver;ecological land protection policies(e.g.,the forest“in-out balance”scheme)effectively reduced the intensity of competition relationship.(4)The push-pull forces of land types demonstrate the dual effect of industrialization and urbanization,but their contribution has gradually weakened as the speed of urbanization declined in various cities;the proportion of the indirect carbon flow reached a maximum of 37%(2005-2010),indicating that the indirect impact of land use change cannot be ignored.This study deepens the understanding of the land-carbon interactions,reveals the implicit effects of the“policy implementation-land use change-carbon flow generation”transmission chain,and proposes a“construction land-cropland-ecological land”constraint system and a synergistic path of industrial land intensification and inefficient land ecological restoration.It provides methodological support for low-carbon governance at the urban agglomeration scale.展开更多
基金Supported by the National Key Research and Development Program of China(Nos.2023YFC3108205,2023YFC3108201)the National Natural Science Foundation of China(No.42306153)。
文摘Pelagic appendicularians,known for their rapid bloom capability,are important secondary producers and play essential roles in marine ecosystems.To assess the environmental adaptation of the most common appendicularian species Oikopleura dioica in Jiaozhou Bay,Shandong,China,its annual variations in abundance and body size were investigated monthly at 12 stations in 2011,and the relationship between somatic growth and gonadal development was compared with previously published laboratory data.Oikopleura dioica exhibited distinct seasonal abundance patterns,peaking in summer and autumn,particularly in the inner bay,reflecting its adaptation to the eutrophic conditions and high food availability.Compared to laboratory results,O.dioica in Jiaozhou Bay exhibited shorter body lengths,smaller gonad volumes,and earlier maturation at reduced body sizes,despite high natural chlorophyll-a concentration,suggesting that factors beyond food availability,such as resource competition and environmental stressors,may limit its growth in natural settings.Correlation analysis indicated that the somatic growth of natural O.dioica was primarily influenced by temperature,while gonadal development was related to chlorophyll-a concentration,and its population abundance was linked to food availability and the abundance of other zooplankton,such as copepods and jellyfish.It was suggested that the growth and recruitment of O.dioica were constrained by resource limitations in natural environments,further exacerbated by interactions with other zooplankton,including predation and competition.This study provides valuable data on the mechanisms underlying bio-environmental interactions and their spatiotemporal variations,offering critical insights into the ecological roles of appendicularians in marine ecosystems.
基金Supported by the Laoshan Laboratory(No.LSKJ202204005)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA23050502)+2 种基金the State Key Program of National Natural Science Foundation of China(No.42130411)the International Science Partnership Program of the Chinese Academy of Sciences(Nos.121311KYSB20190029,133137KYSB20200002)the Key Deployment Project of Centre for Ocean Mega-Research of Science,Chinese Academy of Sciences(CAS)(No.COMS2019J03)。
文摘Nutrients play a crucial role in sustaining marine ecosystems and supporting mariculture,especially in seaweed aquaculture.Currently,seaweed farming,such as kelp cultivation,is entirely dependent on the natural supply of nutrients.Sanggou Bay in Shandong Peninsula,Yellow Sea,is renowned for its 60-year history of kelp cultivation;however,it is recently facing an increasing demand for nitrogen and phosphorus due to the expansion in aquaculture scale and production.There is no doubt that nutrient addition can enhance and sustain the production,but it is crucial to understand its effect on kelp growth under current nutrients condition and the potential ecological risks.Our in-field nutrient enrichment experiments show that nitrogen and phosphorus additions promoted the kelp biomass during the early growth stages,and have no adverse effects on phytoplankton or seawater nutrient levels throughout the experiment.From a long-term perspective,increasing nutrient supply appears to be an essential strategy for sustaining the aquaculture of kelp.
基金supported by the National Natural Science Foundation of China(Grant No.42371027).
文摘Against the background of rapid urbanization and the“Dual Carbon”goals,analyzing the impact mechanisms of land use change on carbon metabolism is crucial for regional sustainable development.Taking the Guangdong-Hong Kong-Macao Greater Bay Area(GBA)as the study area,we integrate energy consumption data and the Forest Carbon Sequestration(FCS)model to clarify the land use carbon metabolism status based on Ecological Network Analysis(ENA),and systematically analyze the spatiotemporal evolution patterns of urban land use carbon metabolism,interactions between land types,as well as its driving mechanisms in the GBA from 2000 to 2023.The results show that:(1)Over the past two decades,land use changes have exhibited a significant characteristic of“natural land retreat and construction land expansion”,with areas of cropland,forest,and waterbody shrank by 16%,4%,and 4% respectively,while urban land and industrial land increased by 50%and 438%respectively;76% of the reclaimed land was transferred to construction land.(2)The imbalance of carbon metabolism was jointly affected by land use patterns and land use change processes:carbon emissions from energy consumption surged by 116%,while land carbon sequestration capacity decreased by 12%;in most periods,the negative carbon flow from land use change exceeded positive flows,with both showing sharp fluctuations.(3)Construction land in various cities dominated the carbon flow network through control or exploitation relationships,and the mutual transfer between industrial land and cropland is the primary driver;ecological land protection policies(e.g.,the forest“in-out balance”scheme)effectively reduced the intensity of competition relationship.(4)The push-pull forces of land types demonstrate the dual effect of industrialization and urbanization,but their contribution has gradually weakened as the speed of urbanization declined in various cities;the proportion of the indirect carbon flow reached a maximum of 37%(2005-2010),indicating that the indirect impact of land use change cannot be ignored.This study deepens the understanding of the land-carbon interactions,reveals the implicit effects of the“policy implementation-land use change-carbon flow generation”transmission chain,and proposes a“construction land-cropland-ecological land”constraint system and a synergistic path of industrial land intensification and inefficient land ecological restoration.It provides methodological support for low-carbon governance at the urban agglomeration scale.
