Effects of climate change on plant growth and phenology
For Kobresia humilis , soil temperature was the most important
factor impacting the green-up period (significantly delayed), the
flowering period (significantly delayed), and the withering period
(significantly advanced), and the optimum thresholds were 38, 54, and 54
days. Maximum air temperature was the most important factor for the
fruiting period (significantly delayed), with an optimum threshold of
more than 60 days (Tables S2 and S3, Fig. 4a).
For Astragalus laxmannii , soil temperature was the most important
factor impacting the start of the rapid growth phase (significantly
delayed), with an optimum threshold of 58 days. Air temperature was the
most important factor impacting maximum growth (significantly delayed),
with an optimum threshold of 48 days. Maximum air temperature was the
most important factor determining the end of the rapid growth phase
(significantly delayed), and the optimum threshold was more than 60 days
(Tables S2 and S3, Fig. 4b).
For Stipa purpurea and Artemisia scoparia , soil
temperature was the most important factor impacting the green-up period
(significantly delayed), with an optimum threshold of 58 days
(Artemisia scoparia ) and 56 days (Stipa purpurea ). Soil
temperature was also the most important factor impacting the withering
period (significantly advanced) of Artemisia scoparia (optimum
threshold of 48 days), whereas for Stipa purpurea , temperature
was the most important factor, with an optimum threshold of 40 days
(Tables S2 and S3, Fig. 4c and 4d).
Fig. 1 Trends of green-up, flowering, fruiting, and withering
periods for Kobresia humilis , Astragalus laxmannii ,Artemisia scoparia , and Stipa purpurea over time. Dots
indicate the Julian day, the line indicates the trend of the Julian day
by the linear model, grey areas represent the 95% confidence intervals.
The solid line indicates p -values < 0.05, the dashed
line indicates p -values > 0.05. The blue line
represents significant positive correlations, and the red line
represents significant negative correlations.
Fig. 2 Trends of the start of the rapid growth phase, the
timing of maximum growth and the end of the rapid growth phase forKobresia humilis , Astragalus laxmannii , Artemisia
scoparia , and Stipa purpurea over time. Dots indicate the Julian
day, the line indicates the trend of the Julian day by the linear model,
grey areas represent 95% confidence intervals. The solid line indicatesp -values < 0.05, the dashed line indicatesp -values > 0.05. The blue line represents the
significant positive correlations, and the red line represents the
significant negative correlations.
Fig. 3 Trends of annual peak height, intrinsic growth rate, and
biomass of Kobresia humilis , Astragalus laxmannii ,Artemisia scoparia , and Stipa purpurea over time. Dots
indicate annual peak height, intrinsic growth rate, and biomass. The
lines indicate the trends of annual peak height, intrinsic growth rate,
and biomass by the linear model, grey areas represent 95% confidence
intervals. The solid line indicates p -values < 0.05,
the dashed line indicates p -values > 0.05. The blue
line represents the significant positive correlations, and the red line
represents the significant negative correlations.