Leaf breakdown rates as a functional indicator were influenced by an invasive non-native invertebrate in urban ponds

The structure of stream communities is typically thought to be driven by stochastic events such as floods, in contrast with communities in many other systems in which biotic interactions have a major role. However, it is possible that biotic interactions are important in some situations in streams, especially where resources are limited and physical influences are stable for substantial periods. Leaf litter – the main energy source and a distinct habitat in forest streams – constitutes a patchy resource where biotic interactions among and within consumer species are likely to occur. The intraspecific interference in four leaf-eating species (shredders), common in Australian tropical streams, was experimentally examined – Anisocentropus kirramus (Trichoptera : Calamoceratidae), Lectrides varians and Triplectides gonetalus (Trichoptera : Leptoceridae) and Atalophlebia sp. (Ephemeroptera : Leptophlebiidae). All four species showed some degree of intraspecific interference, indicated by lowered leaf breakdown rates when density increased. Breakdown rates per capita decreased exponentially for all species with increased density, with slight differences among species. These differences were more evident when body size was taken into account, with breakdown rates depressed at lower densities for the two species with larger body sizes, T. gonetalus and Atalophlebia sp. Overall breakdown rates did not always increase with higher densities, because they were compensated for by depressed individual breakdown rates. Our results indicate that intraspecific interference can be an important mechanism regulating leaf breakdown in streams.

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Relationships of shredders, leaf processing and organic matter along a canopy cover gradient in tropical streams

Journal of Limnology ◽

10.4081/jlimnol.2017.1684 ◽

2017 ◽

Vol 77 (1) ◽

Cited By ~ 2

Author(s):

Anna C.F. Aguiar ◽

Vinicius Neres-Lima ◽

Timothy P. Moulton

Keyword(s):

Organic Matter ◽

Large Body ◽

Food Resource ◽

Canopy Cover ◽

Tropical Streams ◽

Leaf Biomass ◽

Leaf Breakdown ◽

Leaf Packs ◽

Leaf Processing ◽

Breakdown Rates

Terrestrial allochthonous organic matter represents a structuring element and an important source of energy and carbon to fauna in small forested streams. However, the role of this matter as a food resource for benthic macroinvertebrates, and consequently, for shredders and their performance in riverine processes, is not clear in low-order tropical streams. Aiming to investigate the relationship between shredders and leaves, we analyzed along a gradient of 8-93% canopy cover biomass and abundance of shredders, accumulated leaves and breakdown rates of local leaves to verify if these parameters were related to shade conditions and to each other. Three hypotheses were tested: i) shredder biomass, accumulated leaves and breakdown rates are related to canopy cover and exhibit higher values in shaded sites; ii) shredder biomass is positively related to accumulated leaves and breakdown rates; and iii) due to the relatively large body size of the important shredders, the association of shredders with leaves and importance to leaf processing should be better expressed in terms of guild biomass than abundance. Shredder biomass varied between 846 and 1506 mg DM m‑2 and accumulated leaves varied between 479 and 1120 g AFDM m-2 across sites. Leaf breakdown rate (k), the only measured variable that varied significantly among sites, varied between -0.0015 and -0.0238 day-1. Neither shredder biomass nor leaf biomass were associated with the shading gradient. On the other hand, shredder abundance and biomass, mainly represented by Triplectides (Trichoptera, Leptoceridae), was positively related to accumulated leaves within sites and to breakdown rates assessed by leaf packs. Leaf breakdown, as assessed by the experimental leaf packs, was associated with shredder biomass, but not with shredder abundance. This result suggests that macroinvertebrates are important for leaf detritus processing and that their biomass reflects their activity, presumably because it is related to their secondary production and perhaps non-consumptive action. Their activity was observed at the scale of leaf packs and not at the scale of variation in canopy cover because apparently canopy did not modulate availability of leaves, which were apparently not limiting to the shredders.

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Riparian plant species offer a range of organic resources to stream invertebrate communities through varied leaf breakdown rates

New Zealand Journal of Marine and Freshwater Research ◽

10.1080/00288330.2021.2005637 ◽

2021 ◽

pp. 1-16

Author(s):

Kristy Hogsden ◽

Sophie O’Brien ◽

Stacey Bartlett ◽

Helen Warburton ◽

Hayley Devlin ◽

...

Keyword(s):

Plant Species ◽

Leaf Breakdown ◽

Invertebrate Communities ◽

Breakdown Rates ◽

Organic Resources ◽

Riparian Plant

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The use of wooden sticks to assess stream ecosystem functioning: Comparison with leaf breakdown rates

The Science of The Total Environment ◽

10.1016/j.scitotenv.2012.07.090 ◽

2012 ◽

Vol 440 ◽

pp. 115-122 ◽

Cited By ~ 29

Author(s):

Maite Arroita ◽

Ibon Aristi ◽

Lorea Flores ◽

Aitor Larrañaga ◽

Joserra Díez ◽

...

Keyword(s):

Ecosystem Functioning ◽

Leaf Breakdown ◽

Stream Ecosystem ◽

Breakdown Rates

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Leaf Breakdown Rates: a Measure of Water Quality?

International Review of Hydrobiology ◽

10.1002/1522-2632(200107)86:4/5<407::aid-iroh407>3.0.co;2-p ◽

2001 ◽

Vol 86 (4-5) ◽

pp. 407-416 ◽

Cited By ~ 38

Author(s):

Cláudia Pascoal ◽

Fernanda Cássio ◽

Pedro Gomes

Keyword(s):

Water Quality ◽

Leaf Breakdown ◽

Breakdown Rates

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Evaluating the effect of macroinvertebrate exclusion on leaf breakdown rates in two upland Colombian streams

Revista de Biología Tropical ◽

10.15517/rbt.v66i1.28070 ◽

2017 ◽

Vol 66 (1) ◽

pp. 457

Author(s):

Bladimir Zúñiga-Céspedes ◽

María Del Carmen Zúñiga ◽

Julián Chará

Keyword(s):

Large Body ◽

Leaf Decomposition ◽

Functional Feeding Groups ◽

Wet Season ◽

Mixed Species ◽

Leaf Breakdown ◽

Litter Bags ◽

Breakdown Rates ◽

Density And Biomass ◽

Leaf Species

Macroinvertebrate shredders have been widely recognized as an important functional feeding group that contributes to leaf decomposition in temperate streams, but little is known about their role in upland Neotropical streams. In this study, we investigated the effect of macroinvertebrate exclusion on leaf breakdown rates in two upland streams (Marianela and Peña Bonita with 1 911 and 2 560 m elevation, respectively) in Colombia. We hypothesized that leaf litter breakdown is mediated mainly by macroinvertebrate shredders in Colombian upland streams. The study was carried out between January and April of 2009, including the dry season and the beginning of the wet season. We measured leaf mass loss using coarse- (15 mm; accessible to macroinvertebrates) and fine- (200 µm; macroinvertebrates excluded) mesh litter bags that were anchored with wood stakes to the bottom of each stream and recovered after 7, 14, 21, 28, and 56 days. We selected leaves from two dominant plant species and used three leaf treatments: two single species (Palicourea cuatrecasasii and Critoniopsis ursicola) and mixed-species (P. cuatrecasasii and C. ursicola). We compared leaf breakdown rates between the Peña Bonita and Marianela stream, mesh-sizes, and leaf treatments. Macroinvertebrates that colonized the litter bags were measured for density and biomass and categorized in functional feeding groups. In general, there were no significant differences in breakdown rates between the streams and the mesh-sizes. In contrast, leaf breakdown rates had significant differences between all leaf species, where C. ursicola had higher breakdown rates than mixed-species, and P. cuatrecasasii. Macroinvertebrate exclusion did not affect leaf breakdown rates and their assemblages were composed by high densities of collectors (mainly Chironomidae) and few shredders with a large body size. The similar macroinvertebrate colonization between leaf species, the relatively slow breakdown rates, and the shredder scarcity, suggest that leaves were a refractory substrate. Further studies should include leaf species with different nutritional qualities and larger spatial-temporal scales to test the hypothesis of shredder presence and its role on leaf decomposition in upland Colombian streams.

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Retention, breakdown, and biological utilisation of deciduous tree leaves in an estuarine tidal flat of southwestern British Columbia, Canada

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f07-151 ◽

2008 ◽

Vol 65 (1) ◽

pp. 38-46 ◽

Cited By ~ 9

Author(s):

Takashi Sakamaki ◽

John S Richardson

Keyword(s):

Food Source ◽

Deciduous Tree ◽

Nitrogen Stable Isotope ◽

Leaf Breakdown ◽

Breakdown Rate ◽

Carbon And Nitrogen ◽

Leaf Packs ◽

Breakdown Rates ◽

Stable Isotope Signatures ◽

Upper Intertidal

In an estuarine mudflat connected to a mountainous stream, coarse leaf material from deciduous trees was examined for its utilisation by invertebrates, retention, and breakdown rate. Leaves from the stream were deposited in the upper intertidal parts near the stream mouth. Their standing stocks were high in fall (~23.8 g AFDM·m–2) and mostly disappeared by spring. Breakdown rates of red alder leaf packs were higher at subtidal and lower intertidal stations (k = 0.013–0.027·day–1) than at stream channel and upper intertidal stations (k = 0.006–0.009·day–1). Longer contact of leaves with relatively warmer seawater may have enhanced leaf breakdown by microbial activities. In the upper intertidal stations, the decrease in the amount of deposited leaves from fall to spring (k = 0.023–0.039·day–1) was faster than leaf breakdown in the leaf packs, thus physical export was probably significant in the decrease in deposited leaves. Meanwhile, amphipods dominated the invertebrates colonising leaf packs. The invertebrate densities did not significantly differ between natural and polyester leaf packs, suggesting contribution of leaves as a microhabitat rather than a food source. The carbon and nitrogen stable isotope signatures of amphipods indicated that benthic microalgae were their primary food source regardless of natural or artificial leaf packs.

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