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 emphasize 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 that there is an urgent need for further research.
Northeast Forestry University, Harbin, China
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