Root exudate profiles of wetland plants - a quantitative synthesis of secretion rates

Wetlands are hotspots for carbon sequestration and greenhouse-gas exchange. Root exudation from plants might play an important role in these biogeochemical processes; however, a comprehensive overview of plant species-specific exudation profiles is still lacking, limiting quantitative and mechanistic insight. The primary objective of this synthesis is to summarize available data on root exudation in wetland plants, focusing on studies reporting exudation rates. Additionally, we describe factors influencing exudation rates and composition, and compare exudation profiles across plant functional and taxonomic groups. Organic acids contributed the most to the compounds identified in exudates and were the compound class analyzed most frequently (74 % of observations). Exudation rates of sugars and amino acids were rarely reported and contributed often