The Yarlung Zangbo River basin is an important alley to transport moisture from the Indian Ocean to the inner Tibetan Plateau. With a wide range of elevations from 147 m to over 7000 m above sea level (a.s.l.), ecosystems respond differently to climate change at various elevations. However, the pattern of elevation-dependent vegetation change and how it responds to recent warming have been rarely reported. Here, we investigated the pattern of vegetation greening at different elevations in this river basin using SPOT normalized difference vegetation index (NDVI) data during 1999–2013, and examined its relationship with elevation-dependent changes in temperature and precipitation. The annual NDVI has increased by 8.83% from 1999 to 2013. In particular, the NDVI increased more apparently at lower elevations, but remained relatively stable or even decreased at high elevations. It seems that rising temperature has driven the basin-wide vegetation greening, but the greening rate is in contrast to the pattern of elevation-dependent warming (EDW) with more significant temperature increase at higher elevations. It appears that decreasing precipitation does not reverse the overall increasing trend in NDVI, but relatively limited precipitation (4000 m).

The eastern coastal areas of China span multiple climatic zones, and the impacts of climate warming on their ecological environment show regional differences. In this research, the Normalized Difference Vegetation Index (NDVI) was used as the indicator to characterize the ecological environment, and selected Guangdong, Jiangsu, and Liaoning as its typical research areas. The authors selected the NDVI, average temperature, and precipitation data of the yearly growth season, respectively, from 1982 to 2016. This study adopted the copula functions model based on Markov Chain Monte Carlo to carry out the research of bivariate joint distribution so as to calculate the joint probability, the joint exceedance probability, the joint return period and the co-occurrence return period. The results showed that 1) the temperature and precipitation in the three regions were respectively related to the NDVI sequence showing the characteristic that was correlated at the upper tail and asymptotically independent at the lower tail, which demonstrated that the temperature and precipitation had little effect on NDVI when they reached their minimum values, and the temperature and precipitation had obvious effect on NDVI when they reached their maximum values. 2) The shorter the return period was, the wider the ranges of the climate factor and the NDVI were, showing that when the climate factor was constant, the probability of the NDVI having a shorter return period was higher. The greater the climate factor was, the longer the return period was, indicating that the probability of plant growth inhibition was higher when the climate factor exceeded a certain threshold. 3) The suitable temperature and precipitation for vegetation growth in the three regions gradually decreased from south to north. These results provide some theoretical guidance and scientific foundation for the protection of regional ecological environment and enhance the understanding of the impact of climate change on the ecosystem.

Heavy metals can accumulate in nearby farmland soil through leakage of tailings and suspended dust, thereby posing a threat to local agriculture and human health. This study measured the heavy metal content (mercury, Hg; copper, Cu; zinc, Zn; lead, Pb; cadmium, Cd; selenium, Se; manganese, Mn) of farmland soils and wheat from twelve villages near a tailing dam in Baotou, China to evaluate the potential risks to the local ecosystem and human health. The results of the Contamination Factor (Cf) and Geo-accumulation Index (Igeo) indicated serious soil Hg, Se, and Cu contamination. Nemerow Composite Index (NCI) values showed that ±75% of the total sampling sites suffered heavy metal pollution. Soil Potential Ecological Risk Index (IRs) to the west of the tailings exceeded those to the southwest, demonstrating higher levels of Hg and Cd. The Hazard Quotient (HQ) of Mn for adults and children exceeded 3.0, whereas the HQ of Cu for children exceeded 1.0; the Hazard Index (HIs) for both adults and children exceeded 2.0. The results indicate that long-term consumption of wheat grains contaminated with heavy metals in the study area may result in adverse non-carcinogenic health risks, in particular among children. The accumulation of Cd posed carcinogenic risks to human health in two villages (>1 × 10−4). There is an urgent need to regulate the pollution of farmland soil near the tailings dams to mitigate risks to human health.