Scentific Research

The team of Researcher Ding Yongjian of the Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, has achieved progress in monitoring the characteristics of vegetation in the foreland of glacier using UAVs. The research findings were published in the Science of The Total Environment. Dr. Wei Tianfeng is the first author and Researcher Shangguan Donghui is the corresponding author.

Exposed surfaces following glacial retreat are ideal field laboratories for studying primary vegetation succession. Due to the influence of glaciation, the topography of the foreland of glacier is very complex, which greatly limits the investigation of vegetation in this area. Therefore, many related studies adopt manual ground sampling to carry out vegetation investigation, but studies on vegetation of the area using UAVs have been rare.

In the study, the researchers took the foreland of Urumqi Glacier No. 1 as the research area and investigated vegetation parameters (fractional vegetation cover and plant species diversity) and environment variables (soil organic carbon and total nitrogen) along a chronosequence of retreat of Urumqi Glacier No. 1 by combining manual ground sampling and UAV. They then analyzed soil development and vegetation succession along distance (distance from glacier terminus) and time (retreat time of glacier) gradients as well as the relationships between topographic (slope, aspect) and environment variables (organic carbon and total nitrogen), distance, time, and species distributions.

The results indicated that: (1) plant diversity and fractional vegetation cover showed increasing trends with increases in distance and time, whereas soil nutrient content varied nonlinearly; (2) Silene gonosperma, Leontopodium leontopodioides, and Saussurea gnaphalodes were the dominant species in the early, transient, and later succession stages, respectively. Cancrinia chrysocephala occurred in all stages and had a high abundance in the early and later stages; and (3) the relationships of fractional vegetation cover with soil nutrient content were nonlinear. Moreover, distance and time played important roles in species distribution. These findings confirmed that distance and terrain age positively affect vegetation succession. The continuous restoration of vegetation facilitated the accumulation of soil nutrition, but this trend was affected by the rapid growth of plants. Caryophyllaceae and Asteraceae were the most common plants during the succession stages, and the former tended to colonize in the early succession stage. It can be concluded that the UAV-based method exhibits a high application potential for assessing vegetation dynamics in glacier forelands, which is of great significance for long-term and repeated monitoring on the process of vegetation restoration and succession in deglaciated areas.