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A complèter : pagination et WOS; International audience; Large wood (LW, or pieces of dead wood longer than 1 m and thicker than 10 cm in diameter) is a key element in forested streams, but its abundance has decreased worldwide as a result of snagging and clearing of riparian forests. Therefore, many restoration projects introduce LW into stream channels to enhance geomorphology, biotic communities, and ecosystem functioning. Because LW enhances the retention of organic matter and sediments, its restoration can reduce siltation in receiving reservoirs, although so far little information on this subject is available. We studied the effects of restoring the natural loading of LW in four streams in the Aiako Harria Natural Park (the Basque Country, Spain) in pool abundance, channel form, and storage of organic matter and sediments. In all reaches log jams induced the formation of new geomorphic features and changes in physical habitat, especially an increase in the number and size of pools and in the formation of gravel bars and organic deposits. The storage of organic matter increased 5- to 88-fold and streambed level rose 7 ± 4 to 21 ± 4 cm on average, resulting in the storage of 35.2 ± 19.7 to 711 ± 375 m3 (733–1400 m3 ha− 1 y− 1) of sediment per reach. Extrapolation of these results to the entire drainage basin suggests that basinwide restoration of LW loading would enhance the retention potential of stream channels by 66,817 ± 27,804 m3 (1075 m3 ha− 1 y− 1) of sediment and by 361 t (5.32 T ha− 1 y− 1) of organic matter, which represents 60% of the estimated annual inputs of sediments to the downstream Añarbe Reservoir and almost twice as much as the annual input of organic matter to the entire river network. Therefore, basinwide restoration of LW loading is a potentially important tool to manage catchments that feed reservoirs, where retention of sediments and organic matter can be considered important ecosystem services as they reduce reservoir siltation.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:22:34Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:28:27Z : No. of bitstreams: 1 2-s2.0-36749088057.pdf: 498404 bytes, checksum: 285ddc75404dcd37ea32f681eb98907a (MD5) Made available in DSpace on 2014-05-27T11:22:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-09-01 This study objective was to evaluate the effective revegetation in a Mogi Guaçu River degraded floodplain area, located at Luiz Antonio municipality (21° 31' S e 47° 55' W), São Paulo State, Brazil. Two native riparian forest remnants (RIP1 and RIP2) and three 10-year-old reforested areas, planted of native species (R1, R2 and R3), were analyzed by using phytosociological describers of the arboreal stratum (trees with DBH ≥ 5 cm) as indicators. The arboreal stratum inventory was accomplished by 180 plots (10 × 10 m each), 60 representing every native forest and 20 for every reforested area. A total of 60 arboreal species was recorded, only six species (Cecropia hololeuca, Crotón urucurana, Genipa americana, Inga striata, Nectandra megapotamica e Peltophorum dubium) occurring in all the five studied areas. Seventeen species were common to both native forests, and nine species were recorded in all the reforested areas. Sebastlania commersonlana and Guarea macrophyllawere recorded in the native forests (RlP1 and RIP2), and Cecropia hololeuca, Croton urucurana and Inga striata occurring in all the reforested areas, were the species that best characterize the physiognomy of local diversity and were the most important among the studied species. The results showed that the rehabilitation of the areas made by the reforestation created conditions to implant forests with similar structures of the adjacent natural remainders. The reforestation with native species performed in the degraded floodplain of Mogi Guaçu River, initially with the predomination of invasive grasses, has been effective at the first stage of the ecological restoration process. The reforestation is making possible the natural regeneration of species from the adjacent remnants, what indicates that the similarity between planted forests and the native ones are rising through the time. The phytosociology, accomplished ten years after the planting date, is adequate to evaluate the effectiveness of the reforestation during the restoration process of degradated areas in the Mogi Guaçu floodplain. Curso de Graduação em Engenharia Florestal Centro de Saúde e Tecnologia Rural Campus de Patos, Caixa Postal 64, Patos, PB - 58700-970 Departamento de Produção Vegetal Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista, Via de Acesso Prof. Paulo Donato Castellane, Km 5, Jaboticabal, SP - 14884-900 Biólogo da International Paper do Brasil, Rodovia SP 255 - Km. 41, Luiz Antonio, SP -14210-000 Unidade Univesitária Universidade Estadual do Mato Grosso do Sul, Rodovia Aquidauana / UEMS, Km 12, Aquidauana, MS - 79200-000 Departamento de Produção Vegetal Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista, Via de Acesso Prof. Paulo Donato Castellane, Km 5, Jaboticabal, SP - 14884-900