Plant defense traits are involved in maintaining stability of grasslands under mowing

Lulu Zhang, Wenming Bai, Yunhai Zhang, Hans Lambers, Wen-Hao Zhang

This is a plain language summary of a Functional Ecology research article which can be found here.

Mowing is a common grassland management practice with great impacts on functioning and stability of grasslands. Plant functional defense traits offer a mechanistic link between plant physiological and ecological processes and play a positive role in plant protection against disturbance and herbivores and in response to the abiotic environment. Numerous studies have focused on mean values of traits, which predominantly reflect the effects of dominant species on ecosystem function. In addition to mean values, the variability of traits is also an important trait metric. However, whether these metrics of plant traits play a role in ecosystem stability under mowing remains unknown.

Field mowing experiments in a temperate steppe of Inner Mongolia grasslands, China (credit: Wen-Hao Zhang)

To determine whether and how plant defense functional traits are involved in mediating the effects of mowing on ecosystem stability in a temperate grassland, we explored the effects of mowing with varying stubble heights across time on ecosystem stability, population stability, species asynchrony and richness, dominant species stability and asynchrony, as well as plant defense traits.

We demonstrate that grassland ecosystem stability is enhanced by increasing mowing duration and decreasing stubble height. Mowing-induced increase in abundance and diversity of plant defense traits contributes to ecosystem stability by enhancing species asynchrony and population stability. Moreover, we discover that temporal stability of grassland ecosystems is enhanced by mowing. These findings highlight that plant functional defense traits are involved in stabilizing ecosystem functions of grassland under human-induced environmental changes.