The keystone role of leaf-removing crabs in mangrove forests of North Brazil
Dirk Schories
Audrey Barletta Bergan
Mario Barletta
Uwe Krumme
Ulf Mehlig
Verena Rademaker
Abstract
Principle factors which influence mangroveleaf litter turnover, in particular therole of leaf-removing crabs, were evaluatedin a riverine mangrove site nearBragança (Pará, North Brazil). Ourspecial interest was focussed on the roleof the leaf-removing crab Ucidescordatus. Leaf litter fluxes between themangrove forest and the adjacent estuarywere investigated by estimating the biomassand fate of leaf litter material and propagules. Vegetation is dominated by Rhizophora mangle, with Avicenniagerminans trees, both up to 25 m high,found intermittently. During 1997, Rhizophora trees produced around 1.40 gDW m-2 d-1 of leave fall and0.75 g DW m-2 d-1 of propagules.Leaf decomposition rates on the ground wereabout 0.06 g DW m-2 d-1,irrespective of species, habitat or siteexposure. This amount accounts for <3%of total leaf fall. Average leaf litterbiomass present on the ground was 0.01 gDW m-2 d-1. When the mangroveforest was flooded (on average 10 days permonth) the quantity of leaf litterand propagules washed out with the springtide was 10 and 17 times greater thanduring neap tide. Nevertheless, tidalexport and decomposition together made upless than 39 percent of annual leaf litterfall. The bulk of the remaining amount isapparently removed by Ucides. Eachcrab consumed about 1.30 g DW of leaflitter material and propagules per day.Since the average density of these crabswas 1.38 crabs m-2, it is proposedthat Ucides is a keystone species inBragantinian mangroves.
Schories D., Barletta Bergan A., Barletta M., Krumme U., Mehlig U. and Rademaker V. (2003) The keystone role of leaf-removing crabs in mangrove forests of North Brazil. 11(4): 243-255. 10.1023/A:1025011431984
@article{Schories2003,
Title = {The keystone role of leaf-removing crabs in mangrove forests of North Brazil},
Author = {Schories, Dirk and Barletta Bergan, Audrey and Barletta, Mario and Krumme, Uwe and Mehlig, Ulf and Rademaker, Verena},
Editor = {},
Year = {2003},
Pages = {243-255},
Volume = {11},
Doi = {10.1023/A:1025011431984},
Abstract = {Principle factors which influence mangroveleaf litter turnover, in particular therole of leaf-removing crabs, were evaluatedin a riverine mangrove site nearBragança (Pará, North Brazil). Ourspecial interest was focussed on the roleof the leaf-removing crab Ucidescordatus. Leaf litter fluxes between themangrove forest and the adjacent estuarywere investigated by estimating the biomassand fate of leaf litter material and propagules. Vegetation is dominated by Rhizophora mangle, with Avicenniagerminans trees, both up to 25 m high,found intermittently. During 1997, Rhizophora trees produced around 1.40 gDW m-2 d-1 of leave fall and0.75 g DW m-2 d-1 of propagules.Leaf decomposition rates on the ground wereabout 0.06 g DW m-2 d-1,irrespective of species, habitat or siteexposure. This amount accounts for <3%of total leaf fall. Average leaf litterbiomass present on the ground was 0.01 gDW m-2 d-1. When the mangroveforest was flooded (on average 10 days permonth) the quantity of leaf litterand propagules washed out with the springtide was 10 and 17 times greater thanduring neap tide. Nevertheless, tidalexport and decomposition together made upless than 39 percent of annual leaf litterfall. The bulk of the remaining amount isapparently removed by Ucides. Eachcrab consumed about 1.30 g DW of leaflitter material and propagules per day.Since the average density of these crabswas 1.38 crabs m-2, it is proposedthat Ucides is a keystone species inBragantinian mangroves.},
}
TY - JOUR
AU - Schories, Dirk
AU - Barletta Bergan, Audrey
AU - Barletta, Mario
AU - Krumme, Uwe
AU - Mehlig, Ulf
AU - Rademaker, Verena
TI - The keystone role of leaf-removing crabs in mangrove forests of North Brazil
PY - 2003
SP - 243-255
VL - 11
DO - 10.1023/A:1025011431984
AB - Principle factors which influence mangroveleaf litter turnover, in particular therole of leaf-removing crabs, were evaluatedin a riverine mangrove site nearBragança (Pará, North Brazil). Ourspecial interest was focussed on the roleof the leaf-removing crab Ucidescordatus. Leaf litter fluxes between themangrove forest and the adjacent estuarywere investigated by estimating the biomassand fate of leaf litter material and propagules. Vegetation is dominated by Rhizophora mangle, with Avicenniagerminans trees, both up to 25 m high,found intermittently. During 1997, Rhizophora trees produced around 1.40 gDW m-2 d-1 of leave fall and0.75 g DW m-2 d-1 of propagules.Leaf decomposition rates on the ground wereabout 0.06 g DW m-2 d-1,irrespective of species, habitat or siteexposure. This amount accounts for <3%of total leaf fall. Average leaf litterbiomass present on the ground was 0.01 gDW m-2 d-1. When the mangroveforest was flooded (on average 10 days permonth) the quantity of leaf litterand propagules washed out with the springtide was 10 and 17 times greater thanduring neap tide. Nevertheless, tidalexport and decomposition together made upless than 39 percent of annual leaf litterfall. The bulk of the remaining amount isapparently removed by Ucides. Eachcrab consumed about 1.30 g DW of leaflitter material and propagules per day.Since the average density of these crabswas 1.38 crabs m-2, it is proposedthat Ucides is a keystone species inBragantinian mangroves.
ER -
