Ellenberg Indicator Values Disclose Complex Environmental Filtering Processes in Plant Communities along an...

Area of Science:

• Ecology
• Plant Community Ecology
• Biogeography

Background:

• Ellenberg indicator values (EIVs) traditionally assess environmental conditions from plant communities.
• A novel application of EIVs is investigating environmental filtering in plant community assembly.
• Understanding species' ecological preferences is key to predicting community structure.

Purpose of the Study:

• To explore the utility of EIVs in understanding environmental filtering along an elevational gradient.
• To analyze how community-weighted means (CWM) of EIVs change with elevation.
• To determine if species abundances correlate with their ecological preferences.

Main Methods:

• Calculation of CWM using EIVs for temperature, light, moisture, nutrients, pH, and continentality.
• Analysis of CWM variations along an elevational gradient in Central Italy.
• Correlation analysis between species abundances and their respective EIVs.

Main Results:

• Thermophilous species abundance decreased with elevation, replaced by cold-adapted species.
• Heliophilous species dominated low and high elevations (open habitats), while sciophilous species prevailed in mid-elevations (forest).
• Moisture and soil nutrient preferences showed patterns linked to forest soil characteristics; pH and continentality showed no clear elevational trend.

Conclusions:

• EIVs effectively demonstrate how environmental gradients shape plant communities through filtering mechanisms.
• Species' ecological preferences, as indicated by EIVs, significantly influence their distribution along elevational gradients.
• This study underscores the potential of EIVs for ecological research beyond traditional environmental characterization.