The concept of foraging niche provides an insight into habitat use and dietary information of animals.Knowing intraspecific variation in foraging niche and trophic level is critical to the understanding of the species...The concept of foraging niche provides an insight into habitat use and dietary information of animals.Knowing intraspecific variation in foraging niche and trophic level is critical to the understanding of the species response to environmental changes during the process of range expansion,as well as the habitat management for conservation of threatened species.Using stable isotopic values of eggshell membranes(δ;C andδ;N),we examined whether there are differences in habitat use,trophic level,foraging niche width between the new and old breeding habitats(plains vs.mountains)of wild Crested Ibis(Nipponia nippon)in the early breeding season.Crested Ibis exhibited high variability in bothδ;C andδ;N values,δ;C andδ;N varied as a function of habitat types.Birds breeding in plains had significantly higherδ;C but lowerδ;N values compared to the birds breeding in mountains.Higherδ;N suggested that individuals in mountains consumed a great proportion of higher trophic level prey species in the early breeding season.Moreover,the isotopic niches were distinctly different in positions and showed small overlap between the two habitat types.The niche width was wider in old habitat than in the expanded new habitat.Our results demonstrated that the wild Crested Ibis had a high intraspecific variation in habitat uses and trophic levels in the early breeding season,and they could be divided into mountain and plain groups based on their different foraging niches.The difference inδ;N and niche width revealed that high trophic level food resources might be insufficient in plains.These findings stressed the importance of protecting foraging grounds in mountains and the necessity of improving foraging grounds in plains during winter and spring.Our study highlights the feasibility of investigating intraspecific variation in foraging ecology of birds through non-invasive isotopes of eggshell membranes.Understanding foraging niche variation gives us an insight into the food resource diversity in local areas and provides important information regarding particular foraging habitats that require protection.展开更多
Ecological purification in a reservoir is an important strategy to control the level of nutrients in water.The bacterial community of such a reservoir is the main agent for pollutant degradation,which has not been ful...Ecological purification in a reservoir is an important strategy to control the level of nutrients in water.The bacterial community of such a reservoir is the main agent for pollutant degradation,which has not been fully documented.Taking the Jinze Reservoir,a freshwater source for Shanghai,China as the case,its spatial distributions of water and sediment bacteria were determined using 16S rRNA gene-based Illumina MiSeq sequencing,and the environmental parameters were analyzed.The reservoir takes natural river water and functions as an ecological purification system,consisting of three functional zones,i.e.,pretreatment zone,ecological purification zone,and ecological sustaining zone.Results show that the concentrations of both total nitrogen(TN)and total phosphorus(TP)decreased considerably after the ecological treatment,and the concentration of dissolved oxygen(DO)in the ecological purification zone was boosted from that before pretreatment.In addition,patterns of bacterial communities in both water and sediment were similar and consisted of mainly Proteobacteria,Actinobacteria,and Bacteroidetes.However,difference in water bacterial composition was distinct in each functional zone,whereas the bacterial communities in sediment changed only slightly among sediment samples.Network analysis revealed nonrandom co-occurrence patterns of bacterial community composition in water and sediment,and Pseudomonas,unclassified Comamonadaceae,Variovorax,and Dechloromonas were the key taxa in the co-occurrence network.The bacterial taxa from the same module of the network had strong ecological connections,participated in C-cycles,and shared common trophic properties.PICRUSt analysis showed that bacteria were involved potentially in various essential processes;and the abundance of predicted xenobiotic biodegradation genes showed a decreasing trend in water samples from the inlet to the outlet of the reservoir.These results improve our current knowledge of the spatial distribution of bacteria in water and sediment in ecological purification reservoirs.展开更多
基金funded by the National Natural Science Foundation of China(No.31772483,31900371)the Biodiversity Survey,Monitoring and Assessment Project of Ministry of Ecology and Environment,China(No.2019HB2096001006)。
文摘The concept of foraging niche provides an insight into habitat use and dietary information of animals.Knowing intraspecific variation in foraging niche and trophic level is critical to the understanding of the species response to environmental changes during the process of range expansion,as well as the habitat management for conservation of threatened species.Using stable isotopic values of eggshell membranes(δ;C andδ;N),we examined whether there are differences in habitat use,trophic level,foraging niche width between the new and old breeding habitats(plains vs.mountains)of wild Crested Ibis(Nipponia nippon)in the early breeding season.Crested Ibis exhibited high variability in bothδ;C andδ;N values,δ;C andδ;N varied as a function of habitat types.Birds breeding in plains had significantly higherδ;C but lowerδ;N values compared to the birds breeding in mountains.Higherδ;N suggested that individuals in mountains consumed a great proportion of higher trophic level prey species in the early breeding season.Moreover,the isotopic niches were distinctly different in positions and showed small overlap between the two habitat types.The niche width was wider in old habitat than in the expanded new habitat.Our results demonstrated that the wild Crested Ibis had a high intraspecific variation in habitat uses and trophic levels in the early breeding season,and they could be divided into mountain and plain groups based on their different foraging niches.The difference inδ;N and niche width revealed that high trophic level food resources might be insufficient in plains.These findings stressed the importance of protecting foraging grounds in mountains and the necessity of improving foraging grounds in plains during winter and spring.Our study highlights the feasibility of investigating intraspecific variation in foraging ecology of birds through non-invasive isotopes of eggshell membranes.Understanding foraging niche variation gives us an insight into the food resource diversity in local areas and provides important information regarding particular foraging habitats that require protection.
基金Supported by the Key Program in the Youth Elite Support Plan in Universities of Anhui Province(No.gxyqZD2020046)the Key Program in the Key University Science Research Project of Anhui Province(No.KJ2020A0716)the Key Research and Development Program of Anhui Province(No.202004i07020010)。
文摘Ecological purification in a reservoir is an important strategy to control the level of nutrients in water.The bacterial community of such a reservoir is the main agent for pollutant degradation,which has not been fully documented.Taking the Jinze Reservoir,a freshwater source for Shanghai,China as the case,its spatial distributions of water and sediment bacteria were determined using 16S rRNA gene-based Illumina MiSeq sequencing,and the environmental parameters were analyzed.The reservoir takes natural river water and functions as an ecological purification system,consisting of three functional zones,i.e.,pretreatment zone,ecological purification zone,and ecological sustaining zone.Results show that the concentrations of both total nitrogen(TN)and total phosphorus(TP)decreased considerably after the ecological treatment,and the concentration of dissolved oxygen(DO)in the ecological purification zone was boosted from that before pretreatment.In addition,patterns of bacterial communities in both water and sediment were similar and consisted of mainly Proteobacteria,Actinobacteria,and Bacteroidetes.However,difference in water bacterial composition was distinct in each functional zone,whereas the bacterial communities in sediment changed only slightly among sediment samples.Network analysis revealed nonrandom co-occurrence patterns of bacterial community composition in water and sediment,and Pseudomonas,unclassified Comamonadaceae,Variovorax,and Dechloromonas were the key taxa in the co-occurrence network.The bacterial taxa from the same module of the network had strong ecological connections,participated in C-cycles,and shared common trophic properties.PICRUSt analysis showed that bacteria were involved potentially in various essential processes;and the abundance of predicted xenobiotic biodegradation genes showed a decreasing trend in water samples from the inlet to the outlet of the reservoir.These results improve our current knowledge of the spatial distribution of bacteria in water and sediment in ecological purification reservoirs.