Plants are changing the way they grow in response to a warming climate, but what’s happening above ground doesn’t necessarily match what’s happening under the surface, according to international experts.

The team analysed 88 studies on the impact of climate change on plant growth, and found herbaceous plants were beginning and ending their growing seasons earlier above ground. However, the researchers say the activity underground for the same plants was unchanged.

In woody plants the researchers say they found the opposite – growth patterns didn’t change above ground but the growing season underground was extended.

The researchers say more data is needed to understand the difference between above and below-ground changes.

Their paper on plant responses to climate change may differ above and below ground as been published in Nature Climate Change.

A press statement announcing the research says:

The timing of plant life events — such as the emergence of spring leaves, flowering and the loss of leaves in the autumn — is crucial for their fitness and survival and has important implications for human food resources, ecosystem functioning and carbon cycles worldwide. Climate change has led to shifts in various plant life events, as demonstrated by above-ground changes. However, changes that may be occurring in the soil have been under-investigated — despite the important role of root systems in plant growth and terrestrial ecosystem productivity.

Xuhui Zhou and colleagues analysed data from 88 published studies, revealing a mismatch between above- and below-ground plant responses to climate change, which differ depending on the type of plant investigated. Herbaceous plants, for example, were found to have an earlier start and end to their above-ground growing season, resulting in no change in overall growing season length; however, below-ground responses remained unchanged. By contrast, in woody plants, climate warming did not change above-ground responses but did extend the below-ground growing season.

In their conclusion, the authors emphasise caution in interpreting these results given the study’s small sample size. This is owing to available data constraints, in particular, the limited availability of studies focused on below-ground changes, which can strongly influence plant growth and terrestrial carbon cycles. Subsequently, they suggest  there is an urgent need for further research

Link to research (DOI): 10.1038/s41558-021-01244-x

Source:  Scimex