Perfect Shanghai Community Support Mechanism importance

With the aging of our population is growing significantly, pension issues are also increasingly prominent in the family pension, social pension and retirement communities, and retirement communities have both advantages and both have their own characteristics and become an effective means to solve the pension problem, Shanghai is currently analyzing the situation and problems of the pension on the basis of the Shanghai community care services continue to improve mechanisms to forward the healthy and orderly development of Shanghai pension service mechanism.

An evaluation of underlying mechanisms for“fishing down marine food webs”

Since the concept of ＂fishing down marine food webs＂ was first proposed in 1998, mean trophic level of fisheries landings（MTL） has become one of the most widely used indicators to assess the impacts of fishing on the integrity of marine ecosystem and guide the policy development by many management agencies. Recent studies suggest that understanding underlying causes for changes in MTL is vital for an appropriate use of MTL as an indicator of fishery sustainability. Based on the landing data compiled by Food and Agriculture Organization（FAO） and trophic information of relevant species in Fishbase, we evaluated MTL trends in 14 FAO fishing areas and analyzed catches of upper and lower trophic level groups under different trends of MTL and found that both the cases of a recovered MTL trend and a generally increasing MTL trend could be accompanied by decreasing catches of lower trophic level species. Further, community structure and exploitation history should be considered in using MTL after excluding species with trophic levels lower than 3.25 to distinguish ＂fishingthrough＂ from ＂fishing-down＂. We conclude that MTL used as an indicator to measure fishery sustainability can benefit from a full consideration of both upper and lower trophic level species and masking effects of community structure and exploitation history.

Assessing mechanisms for microbial taxa and community dynamics using process models

Disentangling the assembly mechanisms controlling community composition,structure,distribution,functions,and dynamics is a central issue in ecology.Although various approaches have been proposed to examine community assembly mechanisms,quanti-tative characterization is challenging,particularly in microbial ecology.Here,we present a novel approach for quantitatively delineating community assembly mechanisms by combining the consumer–resource model with a neutral model in stochastic differential equations.Using time-series data from anaerobic bioreactors that target microbial 16S rRNA genes,we tested the applicability of three ecological models:the consumer–resource model,the neutral model,and the combined model.Our results revealed that model performances varied substantially as a function of population abundance and/or process conditions.The combined model performed best for abundant taxa in the treatment bioreactors where process conditions were manipulated.In contrast,the neutral model showed the best performance for rare taxa.Our analysis further indicated that immigration rates decreased with taxa abundance and com-petitions between taxa were strongly correlated with phylogeny,but within a certain phylogenetic distance only.The determinism underlying taxa and community dynamics were quantitatively assessed,showing greater determinism in the treatment bioreactors that aligned with the subsequent abnormal system functioning.Given its mechanistic basis,the framework developed here is expected to be potentially applicable beyond microbial ecology.

Microeukaryotic plankton community dynamics under ecological water replenishment:Insights from eDNA metabarcoding

Ecological water replenishment(EWR)is an important strategy for river restoration globally,but timely evaluation of its ecological effects at a large spatiotemporal scale to further adjust the EWR schemes is of great challenge.Here,we examine the impact of EWR on microeukaryotic plankton communities in three distinct river ecosystems through environmental DNA(eDNA)metabarcoding.The three ecosystems include a long-term cut-off river,a short-term connected river after EWR,and long-term connected rivers.We analyzed community stability by investigating species composition,stochastic and deterministic dynamics interplay,and ecological network robustness.We found that EWR markedly reduced the diversity and complexity of microeukaryotic plankton,altered their community dynamics,and lessened the variation within the community.Moreover,EWR disrupted the deterministic patterns of community organization,favoring dispersal constraints,and aligning with trends observed in naturally connected rivers.The shift from an isolated to a temporarily connected river appeared to transition community structuring mechanisms from deterministic to stochastic dominance,whereas,in permanently connected rivers,both forces concurrently influenced community assembly.The ecological network in temporarily connected rivers post-EWR demonstrated significantly greater stability and intricacy compared to other river systems.This shift markedly bolstered the resilience of the ecological network.The eDNA metabarcoding insights offer a novel understanding of ecosystem resilience under EWR interventions,which could be critical in assessing the effects of river restoration projects throughout their life cycle.