Biomass and functional traits of exotic and Cerrado native grass species: a biodiversity experiment in the Chapada dos Veadeiros National Park

In November 2019, a biodiversity experiment was established, sowing 302 plots with different species richness levels and dominance, utilizing eight native Cerrado grass species. Following two growth seasons, in October 2021, aboveground biomass of exotic grasses was harvested from 4 m² plots, while that of native species was collected from two 12.5 x 25 cm subplots within these larger plots. The biomass samples were then oven-dried at approximately 60°C to a constant weight and subsequently weighed. Soil types for each plot were determined by visual assessment, categorized as rocky or clayey based on the presence of laterites. In February 2022, five functional traits of the native species were measured: leaf mass per area (LMA), maximum vegetative height (H), root tissue density (RTD), specific root length (SRL), and total root length (TRL). These measurements were taken from six isolated individuals per species near the experiment. Leaf samples for LMA were hydrated for 24 hours, scanned for area estimation using ImageJ software, then dried and weighed. Maximum vegetative height was measured from five adult individuals in native areas. The root system was assessed by washing soil monoliths and analyzing root segments stained with methylene blue. Root length and volume were quantified using RhizoVision Explorer, and total root length was derived by multiplying specific root length by total root mass. Rao's quadratic entropy (FDQ) was calculated for each plot as an index of functional diversity, producing 31 distinct FDQ values representing various trait combinations.