Pueraria montana is a perennial twining vine species of Pueraria in Leguminosae.Because of its fast growth and strong climbing and covering ability,this species has the potential threat of invading forest ecosystem.Based on the investigation of the occurrence and harm of P.montana in the"four mountains"forest ecosystem in the central urban area of Chongqing,combined with its growth habits and biological characteristics,we comprehensively evaluated its harm risk.The results show that P.montana is widely distributed in the forest ecosystem within the"four mountains"in the central urban area of Chongqing.On average,there was a distribution site of P.montana every 1.38 km of forest road with a scale of 0.43 hm 2/survey point and a coverage of about 42.86%.P.montana mainly occupy forest land by covering and climbing,threatening the original vegetation of forest land.It grows rapidly,and its ability of diffusion and colonization is very strong.The average length of new branches was 11.52 m/year,and the number of effective tillers was 5.25.According to National Forestry Pest Risk Analysis Index System,the risk assessment value of P.montana was 2.51,so it is a medium-risk harmful plant to forestry.It is suggested that the forestry department should strengthen the management of P.montana to prevent its further spread.
In 2022, an eddy covariance site was established in a young oil palm plantation in southeast Dangbo, Bénin, to study the exchange of CO2, energy, and water vapor. This study aims to present the first one-year analysis of seasonal dynamics in energy balance components and net ecosystem exchange above this type of ecosystem in Africa. The first results show that on average during the 2023 year, 55% of net radiation is consumed into actual evapotranspiration, demonstrating the significant amount of latent heat flux in the energy balance, as expected at this tropical humid site. The sensible heat flux was substantial, ranging between 60 and 200 W·m−2, while net radiation varied between 440 and 650 W·m−2. Carbon uptake and net release of CO2 into the atmosphere were permanent at the site. However, the CO2 uptake increases more when rainy events become regular. On average, the mean nighttime CO2 flux was ~8 µmol·m−2·s−1, while during the daytime it was ~−20 µmol·m−2·s−1.
In recent years,soil acidification has been expanding in many areas of Asia due to increasing reactive nitrogen inputs and industrial activities,which may seriously affect the performance of various ecosystem functions.However,the underlying patterns and processes of ecosystem multifunctionality(EMF)are largely unknown at different levels of pH,limiting our understanding of how EMF respond to drivers.This study aims to explore threshold of pH on changes in EMF and differences in the drivers for the changes in EMF on either side of each of the determined pH thresholds.We collected nutrient and environmental databases for raster-level sampling data,totaling 4,000 sampling points.Averaging and cluster-multiple-threshold approach were used to calculate EMF,then quadratic and generalized additive models and Mann-Whitney U were used to determine and test the pH thresholds for changes in EMF,structural equation modellings and variance partitioning analysis were used to explore the main drivers on changes in EMF.The pH threshold for EMF changes in Chinese terrestrial ecosystems is 6.0.When pH<6.0,climate was consistently more important in controlling the variation of EMF than other variables;when pH≥6.0,soil was consistently more important in controlling the variation of EMF than other variables.Specifically,when pH<6.0,mean annual temperature was the main factor in regulating the EMF variation;when pH≥6.0,soil moisture was the main factor in regulating the EMF variation.Our study provides important scientific value for the mechanism of maintaining EMF under global change.For example,with further increases in global nitrogen deposition,leading to increased soil acidification,there are different impacts on EMF in different regions.It may lead to a decrease in EMF in acidic soils and an increase in EMF in alkaline soils.This suggests different management strategies for different regions to maintain EMF stability in the context of future global changes.In the future,more attention should be paid to the biological mechan
