HR: 0800h
AN: H31B-01    [Abstracts]
TI: Hydro-Geomorphologic Effects Of Large Wood Jams On A Third-Order Stream (Tierra Del Fuego, Argentina)
AU: * Mao, L
EM: luca.mao@unipd.it
AF: Dept. Land and Agroforest Environments, University of Padova, Viale dell'Università 16, Padova, 35020, Italy
AU: Andreoli, A
EM: andrea.andreoli@unipd.it
AF: Dept. Land and Agroforest Environments, University of Padova, Viale dell'Università 16, Padova, 35020, Italy
AU: Comiti, F
EM: francesco.comiti@unipd.it
AF: Dept. Land and Agroforest Environments, University of Padova, Viale dell'Università 16, Padova, 35020, Italy
AU: Lenzi, M A
EM: marioaristide.lenzi@unipd.it
AF: Dept. Land and Agroforest Environments, University of Padova, Viale dell'Università 16, Padova, 35020, Italy
AU: Iturraspe, R
EM: iturraspe@tdfuego.com
AF: Subsecretaría de Recursos Naturales de Tierra del Fuego (SRNTF), San Martín 1401, Ushuaia, 9410, Argentina
AU: Burns, S
EM: salibu@agro.unlp.edu.ar
AF: Departamento de Hidráulica, Universidad Nacional de La Plata, Calle 47 Nž 20, La Plata, 1900, Argentina
AU: Novillo, M G
EM: e3@netverk.com.ar
AF: Departamento de Hidráulica, Universidad Nacional de La Plata, Calle 47 Nž 20, La Plata, 1900, Argentina
AB: Dead wood pieces, especially when organized in jams, play an important geomorphic role in streams because of the effects on flow hydraulics, pool formation and sediments storage. The increase of stream morphological diversity and complexity also exerts also an important ecological role. This work reports on geomorphic role of large wood pieces and jams in a third order mountain stream located in the Southern Tierra del Fuego (Argentina), and draining an old-growth nothofagus forested basin not influenced by the beavers damming activity. Even if the in-stream number of wood pieces (length > 1m; diameter > 0.1 m) is comparable to what observed in other climatic areas, the slow growth of the nothofagus forest causes a lower wood abundance in terms of volumetric load. Since the relatively small dimensions of the surveyed large wood pieces, almost the 70% of them demonstrated to have been fluvial transported and the also wood jams reflect the apparent dynamic of wood in the channel. Wood jams exert a significant influence on the channel morphology, representing almost the half of the drop caused by steps and being responsible for the creation of 30% of the pools. The LW-forced pool volume is strongly and positively correlated to the height of the LW jam, and a significant inverse relationship between pool spacing and wood density within is evident if only the LW-forced pools are considered. The geomorphic influence of LW jams is also exerted by a considerable sediment storing capacity.
DE: 1800 HYDROLOGY
DE: 1824 Geomorphology: general (1625)
DE: 1862 Sediment transport (4558)
SC: Hydrology [H]
MN: 2007 Joint Assembly