Effects of extreme snowfall events on litter respiration in subtropical evergreen broad-leaved forests

As an important component and participant of the material cycle of forest ecosystems, litter has a significant
regulatory effect on forest soil respiration.
The input of litter is more
responsive to climate change, especially heavy snowfall events.
Extreme snowfall events affect the structure and function of forest ecosystems by destroying the canopy, which in turn affects the input and decomposition dynamics
of litter species.

In order to explore the response of litter respiration to extreme snowfall events in subtropical evergreen broad-leaved forests, the study relied on the long-term continuous automatic soil respiration observation system set up in the subtropical evergreen broad-leaved forest ecosystem in Ailao Mountain, Yunnan Province, and through continuous observation of soil litter respiration (2011-2018) data analysis, combined with the observation data of soil temperature, soil water content, rainfall, litter input, litter present stock, litter water content, soil nitrate nitrogen and soil ammonia nitrogen content in the same period, Taking an extreme snowfall event in the subtropical evergreen broad-leaved forest of Ailao Mountain in early 2015 as an example, the effects
of extreme snowfall events on litter respiration in subtropical evergreen broad-leaved forests were carried out.
The results of the study found that extreme snowfall had no significant effect on the flux of litter respiration (before snowfall: 1.
18 ± 0.
03 μmol CO2 ^{m-2 s-1}) After snowfall: 1.
19 ±0.
02 μmol_CO2 ^{m-2 s-1} ).
； The relationship between litter respiration and soil temperature, soil moisture content, precipitation and litter water content was significantly correlated in both periods.
However, litter respiration was significantly correlated with soil nitrate nitrogen content in the early stages of extreme snowfall and unrelated in the late stages of extreme snowfall.
Snowfall reduced the sensitivity of soil respiration and litter respiration to temperature by 2.
55% and 2.
32%,
respectively.
The results indicate that extreme snowfall events will also affect the carbon-nitrogen coupling relationship between litter and soil when it affects the input and decomposition of litter matter, which in turn affects litter respiration
.
In the future research on the response of subtropical forests to climate change, it is necessary to continue to pay attention to the response of litter and carbon-nitrogen coupling relationships at soil interfaces to climate change and the feedback
on the carbon-nitrogen processes of ecosystems.

The findings, titled Responses of aboveground litterfall respiration to unexpected snowfall events in Ailao subtropical forests in Southwest China, were published in Applied Soil Ecology
。 The research has received strong support from the National Foundation, the Yunnan Provincial Fund, the 135 Project of the Chinese Academy of Sciences, the Key Laboratory of Tropical Forest Ecology of the Chinese Academy of Sciences and the Ailao Mountain Ecological Station
.

Effects of environmental factors before and after extreme snowfall events on litter respiration in the subtropical evergreen broad-leaved forests of Ailao Mountain