The Role of Aquatic Invertebrates in Processing of Wood Debris in Coniferous Forest Streams

Aquatic invertebrates play an important role in plant decomposition. However, little information is available regarding the relative importance of micro-, meio- and macroinvertebrates in this process, particularly their role in the decomposition of buried organic matter. To investigate the role of these invertebrates in the decomposition of the aquatic macrophyte Vallisneria natans, leaves of V. natans were placed in litterbags with four different mesh sizes (0.025, 0.042, 0.5 and 5mm) and the bags were either incubated at the sediment–water (SW) interface or buried at a depth of 10cm (B10) for 60 days in Lake Nanhu, China, in July 2015. Increased mesh size significantly increased the loss of plant mass. The decomposition rate ranged from 0.0173 to 0.0467day–1 in the SW treatment, and from 0.0083 to 0.0280day–1 in the B10 treatment. Excluding microinvertebrates, burial significantly affected microbial respiration and invertebrate abundance. Increased mesh size increased invertebrate abundance and richness, but did not significantly affect microbial respiration in either treatment. The average contribution of micro-, meio- and macroinvertebrates and microbes to plant mass loss in the SW treatment was 23.1, 13.5, 7.0 and 56.5% respectively, compared with 19.7, 24.5, 12.3 and 43.5% respectively in the B10 treatment. The results of this study reveal the important but underestimated role of micro- and meioinvertebrates in macrophyte decomposition.

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The Distribution of Settled Larvae of the Bryozoans Alcyonidium Hirsutum (Fleming) and Alcyonidium Polyoum (Hassall) on Fucus Serratus L.

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400022839 ◽

1974 ◽

Vol 54 (3) ◽

pp. 665-676 ◽

Cited By ~ 17

Author(s):

P. J. Hayward ◽

Paul H. Harvey

Keyword(s):

Aquatic Invertebrates ◽

Marine Invertebrate ◽

Substrate Selection ◽

Sessile Invertebrates ◽

Fucus Serratus ◽

The Subject ◽

Invertebrate Larvae ◽

Experi Mental Result ◽

Selection Of

The spatial settlement of marine invertebrate larvae is not a random process. The distribution of the adults of a particular species is influenced by the behavioural responses of the animal to a range of environmental stimuli which, in the case of many sessile invertebrates, result in the display of clear substrate selection. The role of habitat selection in determining the distribution of aquatic invertebrates has been the subject of a review by Meadows & Campbell (1972). The selection of algal substrata by the larvae of various intertidal species of Bryozoa has been demonstrated by Ryland (1959); among these, the ctenostomatous bryozoans Alcyonidium hirsutum and A. polyoum were shown to exhibit a strong preference for fronds of the alga Fucus serratus, an experi-mental result which accorded well with the distribution of the two species on the shore (Ryland, 1962).

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Conidium production from leaves and needles in four streams

Canadian Journal of Botany ◽

10.1139/b82-190 ◽

1982 ◽

Vol 60 (8) ◽

pp. 1487-1494 ◽

Cited By ~ 59

Author(s):

Felix Bärlocher

Keyword(s):

Coniferous Forest ◽

Hard Water ◽

Experimental Period ◽

Unit Weight ◽

Coarse Mesh ◽

Black Forest ◽

Additional Species ◽

Conidium Production ◽

Fine Mesh ◽

Forest Streams

Oak leaves and larch and spruce needles in fine-mesh (0.3 mm) and coarse-mesh (3 mm) bags were exposed in two hard-water streams in the Swiss Jura and two soft-water streams in the Black Forest. Periodically, conidium production in samples was determined under defined conditions. Generally, conidium production per unit weight was highest in oak, followed by larch and spruce. In oak and larch, an early peak was followed by a gradual decline; in spruce, conidium production reached an early plateau in the Jura streams but increased throughout the experimental period in the Black Forest streams. Percentage similarity between substrate spora and stream spora was highest for oak, followed by larch and spruce in three of the streams with deciduous riparian vegetation. The reverse sequence occurred in the remaining stream of a coniferous forest. On oak and larch, more fungal species were recovered in fine-mesh than in coarse-mesh bags; however, these additional species were numerically unimportant. Heliscus lugdunensis was the dominant species in early stages of spruce decay. It was replaced at later stages by Alatospora acuminata in the Jura streams and by two other species in the Black Forest streams. On oak and larch, the four or five most common species remained dominant throughout the experimental period.

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Influence of gut morphology on passive transport of freshwater bryozoans by waterfowl in Doñana (southwestern Spain)

Canadian Journal of Zoology ◽

10.1139/z04-055 ◽

2004 ◽

Vol 82 (6) ◽

pp. 835-840 ◽

Cited By ~ 24

Author(s):

Jordi Figuerola ◽

Andy J Green ◽

Katrina Black ◽

Beth Okamura

Keyword(s):

Aquatic Invertebrates ◽

Bird Species ◽

Passage Time ◽

Passive Dispersal ◽

Long Distance Dispersal ◽

Long Distance ◽

Active Dispersal ◽

Intestine Length ◽

Internal Transport

Waterbirds have been proposed as important vectors for the passive dispersal of those aquatic invertebrates and plants that lack a capacity for active dispersal between isolated water bodies. We analysed the frequency of internal transport of bryozoan propagules (statoblasts) by waterbirds in Doñana, Spain, by examining their presence in the intestines and ceca of dead birds and analysing the role of different aspects of gut characteristics in explaining variation in the presence/absence and abundance of statoblasts. Of the 228 samples examined, 7.9% presented intact statoblasts of Plumatella fungosa (Pallas, 1768), Plumatella emarginata Allman, 1844, and two unidentified Plumatella species. For a given bird species, individuals with heavier gizzards and shorter ceca had a lower incidence and abundance of statoblasts in the lower gut. Grit mass and intestine length were unrelated to the presence or abundance of statoblasts. Our results suggest that waterbirds frequently transport bryozoans on a local scale, with lighter gizzards and longer ceca favouring such transport. Lighter gizzards are likely to destroy fewer propagules before they reach the lower gut. Species and individuals with longer ceca are particularly good candidates for long-distance dispersal of bryozoans, given the longer passage time of propagules that enter the ceca.

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