Decomposition of leaf litter mixtures in streams: effects of component litter species and current velocity

Marine-derived nutrients from salmon carcasses and leaf litter inputs from riparian vegetation may interactively support stream biodiversity and ecosystem functioning through enhanced resource heterogeneity. Using a full-factorial design of single- and mixed-species litters, we tested for influences of salmon carcasses on in-stream litter decomposition. Overall, nonadditive (synergistic and antagonistic) effects on decomposition were detected for litter species mixtures, and these effects were explained by litter species composition, but not species richness. In middle to late stages of decay, mixtures of labile (high-quality) litters showed faster than expected mass loss, and recalcitrant (low-quality) litter mixtures showed slower than expected mass loss. The presence or absence of each litter species differentially affected decomposition, but these patterns were stronger when salmon carcasses were available. Across all treatments, the influence of salmon carcasses on decomposition was most pronounced in mid-stages of litter decay, where deceleration of decomposition was likely caused by macroinvertebrates feeding on salmon carcasses and less on litter. Combined, these data demonstrate that salmon carcass inputs to streams can enhance detrital heterogeneity, alter interactions among species in litter mixtures, and influence ecosystem functioning (i.e., decomposition).

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The Role of Animal Associations and Current Velocity in Sediment-Specific Leaf Litter Decomposition

Oikos ◽

10.2307/3543627 ◽

1977 ◽

Vol 29 (2) ◽

pp. 357 ◽

Cited By ~ 34

Author(s):

S. R. Reice

Keyword(s):

Leaf Litter ◽

Litter Decomposition ◽

Current Velocity ◽

Leaf Litter Decomposition

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Mixed leaf litter decomposition and N, P release with a focus on Phyllostachys edulis (Carrière) J. Houz. forest in subtropical southeastern China

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.2015.019 ◽

2015 ◽

Vol 84 (2) ◽

pp. 207-214 ◽

Cited By ~ 2

Author(s):

Lei Shi ◽

Shaohui Fan ◽

Zehui Jiang ◽

Lianghua Qi ◽

Guanglu Liu

Keyword(s):

Leaf Litter ◽

Litter Decomposition ◽

Moso Bamboo ◽

Leaf Litter Decomposition ◽

Southeastern China ◽

Litter Mixtures ◽

P Release ◽

Significant Difference ◽

N Release ◽

Phoebe Bournei

As an important non-wood forest product and wood substitute, Moso bamboo grows extremely rapidly and hence acquires large quantities of nutrients from the soil. With regard to litter decomposition, N and P release in Moso bamboo forests is undoubtedly important; however, to date, no comprehensive analysis has been conducted. Here, we chose two dominant species (i.e., Cunninghamia lanceolata and Phoebe bournei), in addition to Moso bamboo, which are widely distributed in subtropical southeastern China, and created five leaf litter mixtures (PE100, PE80PB20, PE80CL20, PE50PB50 and PE50CL50) to investigate species effects on leaf litter decomposition and nutrient release (N and P) via the litterbag method. Over a one-year incubation experiment, mass loss varied significantly with litter type (P < 0.05). The litter mixtures containing the higher proportions (≥80%) of Moso bamboo decomposed faster; the remaining litter compositions followed Olson’s decay mode well (R2 > 0.94, P < 0.001). N and P had different patterns of release; overall, N showed great temporal variation, while P was released from the litter continually. The mixture of Moso bamboo and Phoebe bournei (PE80PB20 and PE50PB50) showed significantly faster P release compared to the other three types, but there was no significant difference in N release. Litter decomposition and P release were related to initial litter C/N ratio, C/P ratio, and/or C content, while no significant relationship between N release and initial stoichiometric ratios was found. The Moso bamboo–Phoebe bournei (i.e., bamboo–broadleaved) mixture appeared to be the best choice for nutrient return and thus productivity and maintenance of Moso bamboo in this region.

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C, N and P fertilization in an Amazonian rainforest supports stoichiometric dissimilarity as a driver of litter diversity effects on decomposition

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2014.1682 ◽

2014 ◽

Vol 281 (1796) ◽

pp. 20141682 ◽

Cited By ~ 35

Author(s):

Sandra Barantal ◽

Heidy Schimann ◽

Nathalie Fromin ◽

Stephan Hättenschwiler

Keyword(s):

Leaf Litter ◽

Soil Fauna ◽

Individual Species ◽

Litter Mixtures ◽

Mixture Effects ◽

Wide Range ◽

Litter Mixture ◽

Underlying Mechanisms ◽

Strong Control ◽

Diversity Effects

Plant leaf litter generally decomposes faster as a group of different species than when individual species decompose alone, but underlying mechanisms of these diversity effects remain poorly understood. Because resource C : N : P stoichiometry (i.e. the ratios of these key elements) exhibits strong control on consumers, we supposed that stoichiometric dissimilarity of litter mixtures (i.e. the divergence in C : N : P ratios among species) improves resource complementarity to decomposers leading to faster mixture decomposition. We tested this hypothesis with: (i) a wide range of leaf litter mixtures of neotropical tree species varying in C : N : P dissimilarity, and (ii) a nutrient addition experiment (C, N and P) to create stoichiometric similarity. Litter mixtures decomposed in the field using two different types of litterbags allowing or preventing access to soil fauna. Litter mixture mass loss was higher than expected from species decomposing singly, especially in presence of soil fauna. With fauna, synergistic litter mixture effects increased with increasing stoichiometric dissimilarity of litter mixtures and this positive relationship disappeared with fertilizer addition. Our results indicate that litter stoichiometric dissimilarity drives mixture effects via the nutritional requirements of soil fauna. Incorporating ecological stoichiometry in biodiversity research allows refinement of the underlying mechanisms of how changing biodiversity affects ecosystem functioning.

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