Effects of land-use types and the exotic species,Hypochaeris radicata,on plant diversity in human-transformed landscapes of the biosphere reserve,Jeju Island,Korea

Land-use and plant invasion influence biodiversity.Understanding the effects of land-use types and invasive plants on the ecosystem is crucial for better management and the development of strategic plans for increasing biodiversity in Jeju Island,Korea,a designated Biosphere Reserve by the United Nations Education,Scientific,and Cultural Organization.The effect of the most dominant invasive exotic species,Hypochaeris radicata,on the four land-use types of Jeju Island was investigated.Plant composition,soil characteristics,and plant diversity among four land-use types(cropland,green space,neglected land,and residential)were compared.Among the land-use types,croplands had the most diverse plant composition and the highest richness in exotic and native plant species.Croplands,such as tangerine orchards,which are widely distributed throughout Jeju Island,showed the highest plant diversity because of medium intensity disturbance caused by weed removal.The relative cover of H.radicata did not differ between land-use types.However,H.radicata invasion was negatively related with plant species richness,making this invasive species a threat to the biodiversity of native herbs present in land-use areas.H.radicata adapts to areas with a broad range of soil properties and a variety of land-use types.Therefore,it is crucial to monitor land-use types and patterns of plant invasion to guide the implementation of consistent management and conservation strategies for maintaining ecosystem integrity of the transformed habitat in Jeju Island.

Environmental toxicity assessment of chromium (III) oxide nanoparticles using a phytotoxic, cytotoxic, and genotoxic approach

Chromium(III)oxide nanoparticles(NPs)have a wide range of industrial applications,particularly in the production of lithium-ion batteries;however,the toxicity of these NPs has not been studied extensively.The phytotoxicity and genotoxicity of chromium(III)oxide NPs have not been assessed,and only one study reported their cytotoxicity,underscoring the need to perform comprehensive toxicity studies on these NPs.Here,we showed that chromium(III)oxide NPs had no effect on germination rates,and only decreased root elongation in L.sativa as determined by root elongation and biomass studies.Chromium(III)oxide NPs had no phytotoxic effects under environmental realistic conditions,whereas they had cytotoxic effects against HK-2 and Raw 264.7 cells in vitro.However,the cytotoxicity of chromium(III)oxide NPs did not occur under environmentally realistic conditions.The genotoxicity of chromium(III)oxide NPs was not significant in HK-2 cells,suggesting that the potential environmental cytotoxicity of chromium(III)oxide NPs is limited.This study proposes comprehensive phytotoxicity,cytotoxicity,and genotoxicity testing tools that would be easy,safe,and effective for evaluating the toxicity of NPs.This integrated testing system could be an accurate and stable method for evaluating the toxicity of other nanomaterials.