Changes in vegetation phenology on the Mongolian Plateau and their climatic determinants

Abstract

Climate change affects the timing of phenological events, such as the start, end, and length of the growing season of vegetation. A better understanding of how the phenology responded to climatic determinants is important in order to better anticipate future climate-ecosystem interactions. We examined the changes of three phenological events for the Mongolian Plateau and their climatic determinants. To do so, we derived three phenological metrics from remotely sensed vegetation indices and associated these with climate data for the period of 1982 to 2011. The results suggested that the start of the growing season advanced by 0.10 days yr-1, the end was delayed by 0.11 days yr-1, and the length of the growing season expanded by 6.3 days during the period from 1982 to 2011. The delayed end and extended length of the growing season were observed consistently in grassland, forest, and shrubland, while the earlier start was only observed in grassland. Partial correlation analysis between the phenological events and the climate variables revealed that higher temperature was associated with an earlier start of the growing season, and both temperature and precipitation contributed to the later ending. Overall, our findings suggest that climate change will substantially alter the vegetation phenology in the grasslands of the Mongolian Plateau, and likely also in biomes with similar environmental conditions, such as other semi-arid steppe regions.

Effects of multiple climate change factors on the spring phenology of herbaceous plants in Inner Mongolia, China: Evidence from ground observation and controlled experiments

“…A similar conclusion based on species‐level observations was draw in eastern China (Chen et al , ), the TP (Zhu et al , ), and the western United States (Munson and Long, ). On the landscape scale based on the satellite data, a similar conclusion that the warmer temperature accelerated the green‐up of grassland was also reported (Miao et al , ; Cheng et al , ; Wilsey et al , ). From the perspective of the plant physiology, the phenology could respond to the temperature sensitively because plants can precisely sense the absolute and gradual changes in the diurnal and seasonal temperatures with a wide array of thermosensors (Bahuguna and Jagadish, ).…”

“…Our results indicated that the light intensity exerted a significant effect on only 9.7% of the time series. This result is consistent with the result from the remote sensing data, which showed that the relationship between light intensity and the SOS was only significant in 19.1% of grassland pixels (Miao et al , ). Thus, the impact of light intensity on the spring phenology might be weak and indirect.…”

“…Remote sensing is one of the most effective ways to obtain data on the spatiotemporal phenological changes in grasslands. Many studies have investigated the phenological change in Mongolian grasslands based on satellite data (Sha et al , ; Miao et al , ; Ren et al , ; Ren et al , ). The results suggested that the start of the growing season (SOS) advanced by 0.10 days/year, the end of the growing season (EOS) was delayed by 0.11 days/year, and the length of the growing season expanded from 1982 to 2011 in Mongolian Plateau (Miao et al , ).…”

“…In adult trees of temperate species, increasing insolation apparently induces synchronous flowering in May/June (Borchert et al , ). For the grasslands on the Mongolian Plateau, the SOS was significantly correlated with downwards shortwave radiation over 19.1% of the area (Miao et al , ).…”

Climate Warming Does Not Always Extend the Plant Growing Season in Inner Mongolian Grasslands: Evidence From a 30‐Year In Situ Observations at Eight Experimental Sites

“…The linear regression analysis on SOS shows similar results that only around 30% of the plants displayed significant trends in SOS over the study period, yet the directions of these trends are divergent ( Figure 2). This can be supported by a recent study using remote sensing approach and reporting the SOS across 70% of the grasslands in the Mongolian Plateau did not significantly change from 1982 to 2011 (Miao et al, 2017). Even so, numerous other studies based on remote sensing data have suggested an overall advanced SOS under warming climates across biomes in the NH (Cong et al, 2013;Piao et al, 2015;Zhao et al, 2015).…”