Does phenology play a role in the feedbacks underlying shrub encroachment?

Shrub encroachment has emerged as a global phenomenon over the past century. Multiple drivers have been put forward to explain the increased shrub dominance in various ecosystems around the world. However, the potential role of phenology in regulating shrub encroachment is not well understood.

[Seasonal divergence in the responses of vegetation growth to PDO in Tibetan Plateau, China].

Regional-scale normalized difference vegetation index (NDVI) derived from satellite remote sensing observations and gridded climate data were used to study the seasonal responses and underlying mechanisms of vegetation growth over Tibetan Plateau to Pacific Decadal Oscillation (PDO) at period of 1982-2015, by performing Spearman correlation analysis and enhanced multivariate regression model: structural equation model (SEM). The results showed that there was significant negative correlation between PDO index and mean growing-season (April-October) NDVI over Tibetan Plateau; however, marked seasonal divergence in the relationship between PDO and vegetation growth existed among different seasons. It characterized with stronger negative correlation between PDO and NDVI in autumn than in summer, and winter PDO had significant effect on consequent summer vegetation growth.

[Responses of subalpine Betula albo-sinensis soil invertase activity to elevated atmospheric temperature and CO2 concentration in Western Sichuan].

Taking the soil planted with subalpine Betula albo-sinensis seedlings in Western Sichuan as test object, this paper studied the responses of its invertase activity to elevated temperature (ET), elevated atmospheric CO2 concentration (EC), and their combination (ETC). The results indicated that ET increased the soil invertase activity to a certain extent, being significant in May, June, September and October. EC also had a significant positive effect on the enzyme activity from May to October (P < 0.

[Analysis and quality assessment standard of heavy metals and arsenic in Rhizoma et Radix Notopterygii from different localities].

Objective: Five heavy metals (Hg, Cu, Cd, Pb, Cr) and arsenic (As) contents in 57 samples of from 19 localities in Sichuan, Qinghai and Gansu of Rhizoma et Radix Notopterygii sourcing from two plants Notoperygium incusum and N. forbesii has been analyzed to evaluate the content standard of heavy metal and arsenic for drafting the herbal medicine quality.

Method: ICP-AES method was applied to determine As, Cu, Cd, Pb, Cr and CAAS method was applied to determine Hg.