BEIJING, March 4 (Xinhua) -- Chinese researchers have found that the growing season for plants has not increased with global climate warming since 2000.

Researchers from South China Botanical Garden of the Chinese Academy of Sciences used more than 1 million leaf growing records of four tree species from Europe and investigated the temperature sensitivities of spring leaf unfolding and autumn leaf senescence between 1951 and 2013.

Growing season length is controlled both by the start of the season when leaves unfold in spring and the end of the season when leaf senescence occurs in autumn.

The results suggest that since 2000, the length of the growing season has not increased any more due to the decreased temperature sensitivity of leaf unfolding.

The timing of leaf senescence positively correlated with the timing of leaf unfolding from 1951 to 1980, according to the study published in the journal Global Change Biology. However, the correlation was no more significant from 1981 to 2013.

Plant phenology, the timing of periodic biological events in relation to climate fluctuations, has critical impacts on various aspects of ecosystem functions, such as carbon, water and nutrient cycling. Therefore, monitoring the timing of phenological processes is important to the understanding of the impacts of global warming on land ecosystems.