Effects Of Human Activities Change During COVID-19 Pandemic On Tadpole Diversity In Mount Emei

Understanding the impacts of human activities change on biological diversity is a hot spot in current ecology and biodiversity conservation.COVID-19 and the subsequent global pandemic have rapidly and dramatically changed the behavior and the economy of human society.In scenic areas,the pandemic has reduced the number of visitors and changed their scope of activities,which may have a cascading effect on animals.Among all animal taxa,tadpoles play important functional roles in montane streams.They can promote the material exchange,nutrient cycling,energy flow,and the stable and health of food webs.Therefore,exploring the impact of human activity variations caused by COVID-19 on tadpole composition and diversity in streams can provide important information to better protect biodiversity under the pandemic.In this study,tadpole communities in forest streams of Mount Emei were sampled between May and June in2018,2019(before the epidemic)and 2020,2021(after the outbreak of the epidemic),respectively.We also collected microhabitat factors that may determine tadpole compositon and diversity,measured the functional traits of tadpoles,and acquired tadpole phylogenetic data.First,the change of tadpole composition in streams was compared by non-metric multidimensional scaling tests.Then,the effects of human activities on tadpole diversity caused by the epidemic were calculated and compared using null model.Finally,changes of threatened tadpoles(VU,EN,CR)from the IUCN Red List were studied and compared.We believe that this study can provide important support for formulating reasonable tourism policies for biodiversity conservation,and also can provide guidelines for the protection of other taxa.The results and conclusions of the study are as follows.1.A total of 2740 tadpoles belonging to 6 families and 19 species were collected during the 4-year field survey.Specifically,1719 tadpoles(6 families and 19 species)were collected before the epidemic and 1021 tadpoles(5 families and 16 species)were collected after the outbreak of the epidemic.After excluding the influence of microhabitat factors,we found that the number of individuals of tadpole community decreased significantly in the streams with high variation of human activities,but the biomass did not change significantly.The biomass and individual number of tadpole community did not change significantly in the stream with little variation of human activities.Based on the results of non-metric multidimensional analyses,tadpole composition changed larged in streams with high disturbance(such as Huangwanfangqu).Instead,tadpole composition changed little in stream with low disturbance(such as Chadicunxiagou and Lianghekou).2.We found that tadpole taxonomic diversity of streams with high variation of human activities,such as “Huangwanfangqu” and the “Lingongli”,was greatly reduced,as well as tadpole functional diversity of “Huangwan” and “Longdonghe”.However,tadpole phylogenetic diversity of all streams did not change significantly.These results indicated that the changes of human activities caused by the epidemic may lead to the decrease of taxonomic diversity and functional diversity of tadpole community in Mount Emei.3.There were six threatened species in this study,including Leptobrachium boringii(EN),Megophrys omeimontis(VU),Quasipaa boulengeri(VU),Oreolalax omeimontis(VU),Oreolalax major(VU)and Oreolalax popei(VU).Based on the results,there was no significant difference in the number of individuals,biomass,and diversity of threatened species before and after the outbreak of the epidemic,indicating that human activities may be not the main factor affecting threatened species.This study revealed that the decrease of human activities caused by COVID-19 may induce the decrease of the number and diversity of tadpole,associating with the change of tadpole composition.These results can provide important information for understanding the impact of human activities changes on amphibian diversity and conservation during the special period of COVID-19.This study also provides a guideline for studying the impact of changes in human activities on other animal taxa during the pandemic,so as to formulate more effective conservation and management measures.