Wood and leaf debris input in a Mediterranean stream: The influence of riparian vegetation

Abstract

The input and accumulation of wood and leaf litter was monitored for a year in a Spanish Mediterranean stream (Fuirosos), and the relationship of this accumulation with decaying materials from the nearby riparian forest was examined. The study was carried out during a period without natural flood disturbances. Displacement of wood downstream was minimal. Wood accumulation in the streambed was 0.091 kg DW m -2 y -1 , 83 % of which was smaller than 2.5 cm in diameter. Large wood debris was absent due to the youth of the riparian forest (16-y-old Platanus x hispanica plantation with some Alnus glutinosa). The wood remaining in the streambed was not sufficient to retain litterfall during most of the year, except when the stream dried out (July-September). Wood debris in the streambed accounted for 9-14 % of the total debris inputs, the remainder corresponding to leaf litter. Leaf litter input in the streambed via direct fall derived solely from alder and accounted for 0.491 kg DW m -2 y -1 . Lateral litterfall inputs were due to both alders and sycamores (0.308 and 0.022 kg DW m -2 y -1 , respectively), and accounted for 40 % of the total litterfall. These litterfall inputs were similar to those occurring elsewhere in deciduous forests, but wood contribution was too scarce to retain more than a small fraction in the streambed.