Assessment of macrobenthic community function and ecological quality after reclamation in the Changjiang(Yangtze)River Estuary wetland

An ecological optimization project(semi-closed reclamation project)was implemented to control the invasion of Spartina alterniflora,and optimize the habitat of the Chongming Dongtan wetland,in the Changjiang(Yangtze)River Estuary.After project implementation,a macrobenthic ecological survey was conducted in a natural tidal flat and a semi-closed reclamation restoration area within the Chongming Dongtan wetland from 2019 to 2020.Compared with historical data before reclamation,findings showed that the groups,numbers,and species diversity of the macrobenthos increased significantly,and the ecological optimization project resulted in good ecological benefits.In addition,compared to the natural tidal flat,the number of collected macrobenthic phyla,and the macrobenthic density and biomass were significantly lower in the restoration area.Furthermore,the biodiversity index and functional redundancy of natural tidal flats were generally higher,indicating that the community composition and function of natural tidal flats were relatively more stable.Even though the species composition differed between a number of restoration areas and natural tidal flats,there was no difference in functional diversity,indicating that the effect of restoring ecological functions in restoration areas was optimal.Among them,the biodiversity and functional redundancy of Site S2 were significantly reduced,and the ecosystem function was extremely unstable.Habitat heterogeneity,vegetation community and decreasing salinity were the main factors that affected the ecological functions of macrobenthos.The ecological quality was also evaluated;the Transects N3 and N4 showed good quality.The overall ecological quality of the restoration area was generally high,but that of Site S2 was poor and that of Site S2E was merely good,which was mainly due to modifications of the ecological function of macrobenthos.It is suggested that reeds mowing and freshwater species release should be adopted in restoration areas to improve the community function and the environmental disturbance resistance of the macrobenthos.

Anthropogenic Impacts on Fish Populations in Lake Cayo (Republic of Congo, Central Africa)

Ichthyofaunal diversity and the impact of anthropogenic activities on fish population assemblages were studied in Lake Cayo, a small lake located in the coastal region of the Republic of Congo. Twelve stations were sampled twice over a two-year period. Fishing techniques following standardized methods utilizing monofilament gill nets, and nine environment variables were measured at each station. A total of 11,361 specimens comprising 30 species in 28 genera and 18 families were collected with the Cichlidae being the most diversified. Redundancy Analysis with forward selection coupled with Monte Carlo permutation tests identified depth, pH and substrate as accounting for 57.7% of the total variance among the nine variables sampled (p < 0.05). The low Shannon’s diversity (1.16 ± 0.33) and Equitability (0.43 ± 0.12) indices at all sites, suggest that the Lake Cayo system is in poor ecological health.

Two-step calculation method to enable the ecological and human health risk assessment of remediated soil treated through thermal curing

The centralized utilization of heavy-metal-contaminated soil has become the main strategy to remediate brownfield-site pollution.However,few studies have evaluated the ecological and human health risks of reusing these remediated soils.Considering Zn as the target metal,systematic pHdependent leaching and the Community Bureau of Reference(BCR)extraction were conducted at six pH values(pH=2,4,6,8,10,12)for the remediated soil treated through thermal curing.The pHdependent leaching results showed that with the formation of ZnCr2O4 spinel phases,the remediated soil exhibited strong inherent resistance to acidic attack over longer leaching periods.Furthermore,the BCR extraction results showed that the leaching agent pH value mainly affected the acid-soluble fraction content.Moreover,a strong complementary relationship was noted between the leaching and acid-soluble fraction contents,indicating that the sum of these two parameters is representative of the remediated soil risk value.Therefore,we proposed a two-step calculation method to determine the sum of the two heavy metal parameters as the risk value of remediated soil.In contrast to the traditional one-step calculation method,which only uses the leaching content as the risk value,this two-step calculation method can effectively avoid underestimating the risk of remediated soil.

Research on Health Evaluation of Sustainable Regional Innovation Ecosystems Based on Improved Niche Suitability Model

While researchers have used the traditional index system–part of the niche-fitness model–to evaluate the innovation ecosystem,this index system can be seen as not being sufficiently objective,with the consequent problem that it gives equal weight to the indicators and so does not specify the important factors.To remedy this problem of insufficient objectivity,this paper seeks to improve the traditional niche-fitness model in two ways,which are based on the theory of the innovation ecosystem.First,by introducing the principal components analytic method to solve multiple mutual linear problems.Second,by constructing a new evaluation index system from the four aspects of openness,synergy,sustainability,and growth.This new evaluation index system is closer to the characteristics of the organic and evolutionary nature of the sustainable innovation ecosystem compared with the traditional index system.By using the evaluation index system,the research carries out a health assessment for the sustainable innovation ecosystems in different regions of provincial and municipal China from the two perspectives of descriptive and quantitative analyses.Through these analyses,our findings suggest that the sustainable regional innovation ecosystems in China are,on the whole,in an imbalance:there is a gradual decreasing trend from the eastern coastal areas to the central and western regions,and then the northeast regions.