A comparison of nutrient sources of the epiphyte Tillandsia capillaris attached to trees and cables in Cordoba, Argentina

Abstract

Tillandsia capillaris Ruiz and Pav is an atmospheric epiphytic bromeliad able to grow attached to both trees and power lines in the arid–semiarid regions. We evaluated the influence of support type on nutrient sources of atmospheric bromeliads through of: a) quantity and chemical composition of material retained in the leaf surface (MRL) (dry weight, pH, nitrate, ammonium, phosphate and sulfate contents); b) chemical composition of plant tissues (nitrogen, phosphorous, carbon and chlorophyll contents); and c) nitrogenase activity and abundance of microbial functional groups involved in N cycling in leaf surface (phyllosphere). In the cable situation, MRL was lighter, more acidic, with a higher nitrate and sulfate content and lower phosphate content than in the tree situation. T. capillaris plant tissues on trees had lower N (89%) and higher C (6%) content than plants on cables. Phyllosphere micro-organisms' abundance and nitrogenase activity were similar in both situations. Our results indicate that T. capillaris has similar nutrient sources in both supports, and in consequence atmospheric bromeliads do not need plant host for their nutrition.