Tree canopy, fertilization and soil amendment effects on pasture floristic composition: Case study on a dryland Montado Mediterranean pasture ecosystem

Abstract

Montado is a characteristic ecosystem of the Mediterranean region. The adequate management of this silvo-pastoral ecosystem requires good understanding of the effect of factors such as tree canopy, fertilization or soil amendment on pasture growth. The main objective of this work was to test the floristic composition assessment as a bio-indicator of each study area (under and outside tree canopy, UTC and OTC, respectively), temporally sensitive to soil improvements (amendment and fertilization). In this study, 24 sampling points (half UTC and half OTC) were defined in an experimental field with about 2.3 ha. Pasture floristic composition was evaluated every two years (2016, 2018 and 2020) in the spring flowering period to monitor pasture spatial and temporal evolution. Soil amendments were carried out in November 2017 and June 2019, and soil fertilization was carried out in December 2018. The results of floristic inventory were submitted to a multilevel pattern analysis (Indicator Species Analysis – ISA). Pasture biodiversity was evaluated based on the calculation of richness and relative abundance indices. Pasture species were identified as potential ecological and dynamic attributes (bio-indicators) characteristic of each study area (UTC and OTC), before and after soil amendment and fertilization.