# Impact of Snow on Vegetation Green-Up on the Mongolian Plateau

## TL;DR

This study examines how snow affects when plants start to grow on the Mongolian Plateau, showing that snow melt and coverage influence the timing of vegetation growth.

## Contribution

The study introduces a Cox survival analysis model to quantify the impact of snow cover and melt on vegetation green-up timing.

## Key findings

- Snow cover fraction and melt date significantly influence vegetation start of growing season on the Mongolian Plateau.
- Vegetation green-up occurs earlier in the eastern part of the Mongolian Plateau compared to the west.
- The Cox model shows differential responses of vegetation SOS to snow-related factors.

## Abstract

Snow serves as a crucial water source for vegetation growth on the Mongolian Plateau, and its temporal and spatial variations exert profound influences on terrestrial vegetation phenology. In recent years, global climate change has led to significant changes in snow and vegetation start of growing season (SOS). Therefore, it is necessary to study the mechanism of snow cover on vegetation growth and changes on the Mongolian Plateau. The study found that the spatial snow cover fraction (SCF) of the Mongolian Plateau ranged from 50% to 60%, and the snow melt date (SMD) ranged from day of the year (DOY) 88 to 220, mainly concentrated on the northwest Mongolian Plateau mountainous areas. Using different SOS methods to calculate the vegetation SOS distribution map. Vegetation SOS occurs earlier in the eastern part compared to the western part of the Mongolian Plateau. In this study, we assessed spatiotemporal distribution characteristics of snow on the Mongolian Plateau over the period from 2001 to 2023. The results showed that the SOS of the Mongolian Plateau was mainly concentrated on DOY 71-186. The Cox survival analysis model system established SCF and SMD on vegetation SOS. The SCF standard coefficient is 0.06, and the SMD standard coefficient is 0.02. The SOSNDVI coefficient is −0.15, and the SOSNDGI coefficient is −0.096. The results showed that the vegetation SOS process exhibited differential response characteristics to snow driving factors. These research results also highlight the important role of snow in vegetation phenology and emphasize the importance of incorporating the unique effects of vegetation SOS on the Mongolian Plateau.