Colder Alpine Grasslands Show Less Integrated Plant Trait Networks

Plant communities in colder, higher-altitude grasslands had less connected and more fragmented networks of functional traits than communities in warmer, lower-altitude grasslands, according to a field study across three alpine grasslands in northern Italy. The researchers combined measurements of 18 plant and environmental traits with network analysis and found that rising altitude was associated with lower overall connectivity, fewer trait interdependencies and reduced centrality for individual traits. Groups of strongly associated traits also became smaller and more fragmented, indicating a loss of coordinated trait organization under colder conditions.

The observational study used an altitudinal gradient as a natural proxy for temperature variation. Its population comprised vegetation from three alpine grassland sites in northern Italy, where increasing elevation was accompanied by lower temperatures and harsher environmental conditions. The design captured differences in the structural organization of trait relationships across sites, but it did not isolate temperature as the sole cause of those differences.

To build the plant trait networks, or PTNs, the team integrated the 18 plant and environmental trait measurements with analytical tools designed to quantify patterns of connectivity, community structure and the relative importance of individual traits. Traditional trait analyses commonly focus on a single trait or pairwise correlations. PTNs instead examine how multiple measured traits form an interconnected structure, allowing the researchers to assess both links among traits and the groups into which strongly associated traits cluster.

Centrality provided an additional measure of the relative importance of individual traits within that structure. Across the gradient, the network pattern was consistent on all three structural measures examined. As altitude increased and temperature declined, overall network connectivity fell, the number of interdependencies among traits diminished, and the centrality of individual traits declined.

Communities of strongly associated traits simultaneously became smaller and more fragmented. Together, these observations show that the colder grassland communities had a less cohesive functional organization across the traits measured, rather than merely lower values for one trait or one isolated correlation. The study therefore demonstrates how network analysis can characterize coordinated changes in plant traits across an environmental gradient, while remaining an association among site conditions, temperature and trait-network structure rather than a controlled demonstration of a temperature effect alone.

The authors suggest that PTNs may be useful for evaluating ecosystem resilience under environmental change, but the three-site comparison establishes the potential of the method rather than a direct test of resilience outcomes.

Subject of Research: Effects of an altitudinal temperature gradient on plant functional-trait networks in northern Italian alpine grasslands

Article Title: Network-based characterization of temperature effects on the structural organization of productive Italian grasslands

Article References: Andres, E., Niedrist, G., & Mejia-Aguilar, A. (2026). Network-based characterization of temperature effects on the structural organization of productive Italian grasslands. BMC Plant Biology. https://doi.org/10.1186/s12870-026-09614-3

Image Credits: AI Generated

DOI: 10.1186/s12870-026-09614-3

Keywords: alpine grasslands, plant functional traits, temperature gradient, trait networks, network analysis, altitudinal gradient, ecological organization, climate change, plant ecology, Network-based, characterization, temperature