Plant community composition and interspecific relationships among dominant species on a post-seismic landslide in Hongchun Gully, China

The 5.12 Earthquake in 2008 and 8.14 Debris Flow in 2010 resulted in large-scale landslides that disturbed vast areas of vegetation in the Hongchun Gully, Wenchuan County, China. To define the specific characteristics of vegetation restoration during natural recovery after catastrophic events,vegetation species composition and interspecific associations were investigated on this typical landslide. Field survey data selected from a total of 51 sample plots belonged to seven belt transects and were analysed by Schluter's variance ratio, pearson's chi-squared test, Spearman's correlation coefficients and ecological species groups. Plant communities on the landslide consisted of 78 species, 65 genera and52 families. Of the total of 78 species, 25 are identified as dominant species, among which Camptotheca acuminate, Toxicodendron vernicifluum, Coriaria nepalensis, Robinia pseudoacacia, Buddleja alternifolia, Anemone vitifolia and Nephrolepis auriculata play a constructive role during the natural afforestation. Moreover, according to environmental and ecological factors, these 25 dominant species could be divided into four ecological species groups.This study found that even though the landslide had frequently suffered from interference due to heavy rain, the vegetation succession processes are ongoing,and it is now at a shrub–herb community succession stage, which indicates that vegetation can naturally recover in the denuded sites. This study provides a useful insight into the ecological interactions and interdependence between plant species during the natural recovery of vegetation and provides valuable information on vegetation recovery modelling in the landslide area.

The Impact Of Oil Spill To The Total Petroleum Hydrocarbon(Tph)Concentration In Fishes At North Coastal Of Karawang Regency,West Java Province

The coastal area is one of the areas that is quite vulnerable to the threat of pollution caused by human activities,including pollution caused by oil spills(hydrocarbons)in the sea.The incident can be caused by several factors including the explosion,leakage of petroleum pipelines on the seabed,leakage of tanks or petroleum tankers at sea and disposal of waste petroleum products into the environment.Oil spills continuously can cause environmental contamination and pollution both aquatic and terrestrial.If the petroleum hydrocarbons enter sea waters,some of them will be absorbed by aquatic organisms because the nature of the petroleum hydrocarbons is difficult to decompose in waters.The intentional and unintentional entry of hazardous and toxic substances into marine ecosystems such as petroleum hydrocarbons and chemical solvents resulting from industrial wastes has become a serious problem for human health and the environment.The purpose of this study was to determine the concentration of Total Petroleum Hydrocarbon(TPH)contained in fish in coastal waters of Karawang Regency,West Java Province.This research was conducted in September-November 2019 by taking several fish samples at Ciparage Jaya Fish Auction Place,Betok Mati and Sungai Buntu Rive with a total sample of 24 fish,and taking seawater samples in the three study sites.TPH analysis was carried out at the Integrated Chemistry Laboratory,Bogor Agricultural University.TPH values in fish at Ciparage-1,Ciparage-2,Betok Mati and Sungai Buntu stations,in general,have different mean values but are almost uniform,each at 6.82;6.82;7.45 and 5.12 mg/kg.Based on the average TPH concentration in fish,it can be said that the average TPH in fish at Betok Mati station is relatively higher compared to other stations.TPH values in all fish samples exceed the safe threshold,which is a maximum of 0.002 mg/kg.Based on the results of the Bioaccumulation factor(BAF)analysis showed that the average TPH in fish was 6.55 mg/kg and the average TPH in the waters was 11.23 mg/l,so the BAF value was 58.35 which means that the absorption rate of TPH by fish organisms against the concentration of TPH in the waters of 58.35%.The analysis shows that the value of Ecological Hazard Assessment(EHA)is 3743.33 which means that the level of influence of the hazard on ecosystems and organisms is 3743.33.This value exceeds the recommended threshold according to the European Union,which is a maximum of 0.002 mg/l.

Heavy metal pollution characteristics and health evaluation of farmland soil in a gold mine slag area of Luoyang in China

The characteristics of eight heavy metals(lead,zinc,copper,nickel,chromium,cadmium,mercury and arsenic)in the surface soil of the historical slag area of the Au ore dressing plant in the South-West of Luoyang City were investigated and evaluated in terms of a pollution index,potential ecological hazards and health risks.The results showed that the average amounts of the heavy metals Pb,Zn and As in the soils of plots S3,S5,S7,S12 and S18 exceeded the soil pollution risk screening values.The Mero comprehensive pollution index in plots S7,S12 and S18 was greater than 3,indicating severe pollution.The severe pollution plot integrated the potential ecological risk index(RI)of each sampling point,which was in the order of RI_(S12)>RI_(S18)>RI_(S7)>RI_(S5)>RI_(S3).Among the heavy metals,Cd poses the greatest threat to ecological and human health.The effects of heavy metals in soil on the single non-carcinogenic health risk index(HQ)and the non-carcinogenic total risk index through three exposure pathways were in the order of HQ_(Hg)<HQ_(Cu)<HQ_(Ni)<HQ_(Zn)<HQ_(Cd)<HQ_(Cr)<HQ_(Pb)<HQ_(As)<1,which meant that the adult and child total carcinogenic risk(TCR)and individual carcinogenic health risk indices CRAs and CRCd were above the maximum acceptable human health level recommended by the USEPA(10^(-6)).TCRAs and TCRCd accounted for 75.65%and 23.94%of the adult TCR,respectively.TCR^(As) and TCR^(Cd) accounted for 75.93%and 23.97%of the child TCR,respectively.Overall,the TCR of children was greater than that of adults.In summary,the soil in the historical slag area of the Au ore dressing plant constitutes a serious threat to the surrounding ecological environment and to residents.