Response of nutrients, biofilm, and benthic insects to salmon carcass addition

Salmon carcass addition to streams is expected to increase stream productivity at multiple trophic levels. This study examined stream nutrient (nitrogen, phosphorus, and carbon), epilithic biofilm (ash-free dry mass and chlorophyll a), leaf-litter decomposition, and macroinvertebrate (density and biomass) responses to carcass addition in three headwater streams of southwestern Washington State, USA. We used stable isotopes (δ13C and δ15N) to trace incorporation of salmon-derived (SD) nutrients into stream food webs. SD nutrients were assimilated by biofilm, benthic insects (Perlidae and Limnephilidae spp.), and age-1 steelhead (Oncorhynchus mykiss gairdneri). SD nutrients peaked ~2 weeks after carcass addition for insects and fish feeding on carcasses, but indirect uptake of SD nutrients by biofilm and insects was delayed by ~2 months. A strong stable isotope signal did not always correspond with measurable biological change. At reaches 1050 m downstream from carcasses, ammonium concentration, leaf-litter decomposition, and benthic insect density all increased relative to upstream control sites. The strongest responses and greatest SD-nutrient uptake were observed 10 m from decomposing carcasses, with effects generally decreasing to undetectable levels 250 m downstream. Carcass addition to headwater streams can have a transient effect on primary and secondary trophic levels, but responses may be limited to specific taxa near carcass locations.

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The role of stranding and inundation on leaf litter decomposition in headwater streams

Riparian Ecology and Conservation ◽

10.2478/remc-2013-0002 ◽

2013 ◽

Vol 1 ◽

Cited By ~ 5

Author(s):

Hannah L. Riedl ◽

Laurie B. Marczak ◽

Natalie A. McLenaghan ◽

Trent M. Hoover

Keyword(s):

Leaf Litter ◽

Litter Decomposition ◽

Headwater Streams ◽

Leaf Litter Decomposition

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Field exclusion of large soil predators impacts lower trophic levels and decreases leaf‐litter decomposition in dry forests

Journal of Animal Ecology ◽

10.1111/1365-2656.13101 ◽

2019 ◽

Vol 89 (2) ◽

pp. 334-346

Author(s):

Nereida Melguizo‐Ruiz ◽

Gerardo Jiménez‐Navarro ◽

Eva De Mas ◽

Joaquina Pato ◽

Stefan Scheu ◽

...

Keyword(s):

Leaf Litter ◽

Litter Decomposition ◽

Trophic Levels ◽

Leaf Litter Decomposition ◽

Dry Forests ◽

Large Soil

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Effect of small reservoirs on leaf litter decomposition in Mediterranean headwater streams

Hydrobiologia ◽

10.1007/s10750-012-1064-6 ◽

2012 ◽

Vol 691 (1) ◽

pp. 135-146 ◽

Cited By ~ 23

Author(s):

Margarita Menéndez ◽

Enrique Descals ◽

Tecla Riera ◽

Oscar Moya

Keyword(s):

Leaf Litter ◽

Litter Decomposition ◽

Headwater Streams ◽

Leaf Litter Decomposition ◽

Small Reservoirs

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Termite Control of Leaf Litter Decomposition of Eight Selected Plant Species of Sudano-guinea Savannahs of Ngaoundere, Cameroon

Journal of Agriculture and Ecology Research International ◽

10.9734/jaeri/2020/v21i430138 ◽

2020 ◽

pp. 13-26

Author(s):

A. Ibrahima ◽

S. Kalba Sirzoune ◽

P. Badakoa ◽

A. A. Mang A. Menick ◽

P. Souhore

Keyword(s):

Soil Fertility ◽

Mass Loss ◽

Leaf Litter ◽

Litter Decomposition ◽

Plant Species ◽

Decomposition Rate ◽

Dry Mass ◽

Leaf Litter Decomposition ◽

Resource Quality ◽

Maytenus Senegalensis

Few studies on effects of termites on litter decomposition have been done in African savannahs, particularly in the Adamawa savannahs of Cameroon. In the framework of management of resource quality to restore or improve soil fertility of farming systems of Sudano-guinea savannahs of Ngaoundere, Cameroon, study on termites’ control of leaf litter decomposition of eight plant species was conducted on the field. The selected plant species are Bixa orellana, Erythrina sigmoïdea, Ficus polita, Maytenus senegalensis, Mucuna stans, Piliostigma thonningii, Vitex madiensis and Vitellaria paradoxa. Leaf litter samples were incubated in situ using litterbags of 2 mm mesh during 24 weeks in two plots out of canopy, corresponding to two treatments, with and without termites. Experimental design was split-plot with three replications. Collected data was carried out on litter dry mass remaining (LMR). Results showed total mass loss at the end of incubation time (24 weeks) and decomposition rate constants (k) differed significantly among plant species for the two treatments. The values ranged respectively from 23.05% and 0.012 week-1 in V. madiensis to 61.93% of initial dry mass and 0.046 week-1 in P. thonningii for treatment without termites and from 43.88% and 0.022 week-1 in B. orellana to 91.51% and 0.095 week-1 in P. thonningii for treatment with termites. These macro organisms fasted litter decomposition in all plant species, with intensity variation according to species. Litter mass loss and decomposition rate constant (k) correlated with litter thickness, density, area and specific area mass, and these relationships were influenced by the presence of termites. Globally litter decomposition was influenced by termite activities and resource quality. These results contributed to understand litter decomposition process in the sudano-guinea savannahs of Ngaoundere in order improve soil fertility, nutrient cycling and some plant species domestication.

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