Study on dynamic changes of land desertification in the circum-lake zone of the Qinghai Lake in the past 30 years supported by Remote Sensing and Geographical Information System

The circum-lake zone of the Qinghai Lake is one of the most serious regions of desertification on the Qinghai-Tibetan Plateau. Based on Remote Sensing （RS） and Geographical Information System （GIS） techniques, the four sets of remote sensing images acquired in 1976, 1987, 1995, and 2006 were selected to conduct thematic information extraction in 14,300 km2 of land in the circum-lake zone using the Earth Resource Data Analysis System （ERDAS） image and information processing function. In the meantime the off-site interpretation and filed check-correction methods were used to recon- struct the temporal-spatial dynamic changes and differentiation patterns of land desertification in the circum-lake zone in the past 30 years, and based on this, the developmental trend of land desertification in the next 20 years was predicted. The results of the study show that in the past 30 years land desertification in the region experienced a continuous fluctuation between rapid- and slow-development processes in time, while in space it exhibited a few small patchy distributions or sporadic distributions in many places while at the same time, four large sand-dominated distributions stood out and evolved into a circum-lake belt differentiation pattern with a lakeside dike as the connecting line. Due to the integrated effects of climate changes, human activities and artificial rehabilitation, land desertification area in the region in the next 20 years will exhibit an increasing trend in the first 15 years and then increase at a slower rate, and afterward occur in a reverse, decreasing trend.

Effects of fire and nitrogen addition on photosynthesis and growth of three dominant understory plant species in a temperate forest

Aims Fire and atmospheric nitrogen(N)deposition have the potential to influence growth and productivity of forest canopy.However,their impacts on photosynthesis and growth traits of understory plants in forests remain largely unexplored.This study was conducted to examine the effects of burning and N addition on foliar N content,net photosynthesis and growth traits of three dominant shrub species(Vitex negundo,Lindera glauca and Symplocos chinensis)in a temperate forest in Central China.Methods The experiment used a pair-nested design,with four treatments(control,burning,N addition and burning plus N addition)and five replicates.Leaf mass area(LMA),area-based concentrations of foliar N and chlorophyll(N_(area) and Chl_(area)),net photosynthesis(A_(n)),stomatal conductance(g_(s)),maximum photosynthetic rate(A_(max))and maximal carboxylation rate(V_(cmax)),basal diameter,height and branch length(BL)of the three species were measured.Important Findings Across the three species,burning stimulated LMA,N_(area),Chl_(area),A_(n),g_(s),A_(max) and V_(cmax),and consequently enhanced basal diam-eter,height and BL.Nitrogen addition increased A_(n) and gs but did not affect LMA,N_(area),Chl_(area),A_(max),V_(cmax),basal diameter,height or BL.However,N addition strengthened the positive effects of burning on g_(s),V_(cmax),A_(n) and BL.The findings indicate the primary role of light resources in determining plant photosynthesis and growth of understory shrub species after fire and highlight that understory plants should be considered in projection of biomass accumulation and productivity of forests under environmental perturbations.

Artificial intelligence in bladder cancer:current trends and future possibilities

To the Editor:Bladder cancer is the most common malignant tumor of the urinary system in the Asian population.In China,it is reported 80,000 new cases each year with an increasing incidence every year.Among these cases,75%are of non-muscle invasive bladder cancer(NMIBC).In muscular invasive bladder cancer(MIBC)and NMIBC patients,radical cystectomy is considered as a primary approach of treatment due to the higher risk of tumor progression.Furthermore.