Detrital Dynamics and Cascading Effects on Supporting Ecosystem Services

Mancinelli, Giorgio; Mulder, Christian

doi:10.1016/bs.aecr.2015.10.001

Cited by 19 publications

(10 citation statements)

References 225 publications

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“…As has been previously documented in other ecosystems (5,53), aboveground tundra predators can have important indirect effects on the functioning of the belowground community. The findings of our experiment suggest that under ambient conditions, moist tundra exhibits a classic trophic cascade, where high Table 2 and SI Appendix , Tables S3 and S5. densities of a top predator (wolf spiders) tend to suppress intermediate consumers (Collembola; Fig.…”

Section: Discussionmentioning

confidence: 58%

Warming reverses top-down effects of predators on belowground ecosystem function in Arctic tundra

Koltz

Classen

Wright

2018

Proc. Natl. Acad. Sci. U.S.A.

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Predators can disproportionately impact the structure and function of ecosystems relative to their biomass. These effects may be exacerbated under warming in ecosystems like the Arctic, where the number and diversity of predators are low and small shifts in community interactions can alter carbon cycle feedbacks. Here, we show that warming alters the effects of wolf spiders, a dominant tundra predator, on belowground litter decomposition. Specifically, while high densities of wolf spiders result in faster litter decomposition under ambient temperatures, they result, instead, in slower decomposition under warming. Higher spider densities are also associated with elevated levels of available soil nitrogen, potentially benefiting plant production. Changes in decomposition rates under increased wolf spider densities are accompanied by trends toward fewer fungivorous Collembola under ambient temperatures and more Collembola under warming, suggesting that Collembola mediate the indirect effects of wolf spiders on decomposition. The unexpected reversal of wolf spider effects on Collembola and decomposition suggest that in some cases, warming does not simply alter the strength of top-down effects but, instead, induces a different trophic cascade altogether. Our results indicate that climate change-induced effects on predators can cascade through other trophic levels, alter critical ecosystem functions, and potentially lead to climate feedbacks with important global implications. Moreover, given the expected increase in wolf spider densities with climate change, our findings suggest that the observed cascading effects of this common predator on detrital processes could potentially buffer concurrent changes in decomposition rates.

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Section: Discussionmentioning

confidence: 58%

Warming reverses top-down effects of predators on belowground ecosystem function in Arctic tundra

Koltz

Classen

Wright

2018

Proc. Natl. Acad. Sci. U.S.A.

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“…In conclusion, our analysis on Sardinian Hydromantes provided evidence that satellite‐derived climatic and vegetation variables are not only useful in modeling species occurrence, but may also capture the complex nature of Eltonian processes acting at both individual and population levels. The study identified robust background hypotheses for future investigations on urodeles, a group threatened worldwide and acknowledged to play a key functional role in forest‐floor food webs (Catenazzi 2015, e.g., trophic cascades in detrital food webs: Mancinelli and Mulder 2015 and literature cited). In addition, the two scenarios explored suggest hypothesized mechanisms that can be tested in future ecologically realistic models predicting how interindividual variability in wild populations will mediate community‐scale impacts determined by climate changes (Bolnick et al 2011, Des Roches et al 2018).…”

Section: Discussionmentioning

confidence: 88%

Interspecific and interpopulation variation in individual diet specialization: Do environmental factors have a role?

Lunghi

Manenti

Cianferoni

et al. 2020

Ecology

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Individual diet specialization (IS) has important community-and populationlevel implications and its ecological drivers are actively investigated. Here, to test the hypothesis that local environmental conditions may influence IS in wild populations, we analyzed the stomach contents of 395 individuals from eight populations of five allopatric species of European cave salamanders (genus Hydromantes). We assessed whether their degree of individual diet specialization (1) scaled positively with the respective niche widths, in agreement with Van Valen's niche variation hypothesis (NVH), and (2) could be predicted by satellite-derived climatic and vegetation characteristics of the sites where the populations live. Consistent with the NVH, the degree of individual diet specialization increased with the populations' total niche width. Furthermore, two variables describing local nonarboreal vegetation cover and habitat heterogeneity successfully predicted the variation in individual specialization across the eight populations. Climatic factors had a generally low predictive power, with individual specialization in low-and high-elevation populations showing contrasting patterns of co-variation with air temperature in the warmest quarter of the year. However, independently from elevation, specialization peaked under conditions of high nonarboreal vegetation cover and high precipitation regimes. We discussed the results against two mutually nonexclusive scenarios hypothesizing different mechanisms linking environmental factors to salamanders' trophic strategy at an individual and population level. We concluded that satellite-derived climatic and vegetation variables to date generally adopted to model Grinnellian niches might also be useful in predicting spatial variations in dietary habits of populations, that is, their Eltonian niches.

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“…on wrack-associated microbes (e.g., Cullen et al, 1987), we know surprisingly little about the role of these microbes in enhancing secondary production in shoreline systems, and marine systems as a whole. Indeed, while microbes have been proposed as the "hidden" trophic step in detrital food webs in terrestrial and freshwater ecosystems, their bottom-up effects on consumers are poorly understood even in those ecosystems (Mancinelli and Mulder, 2015). Here, we argue that bacteria also form a "hidden" trophic step in wrack along the shoreline in coastal, marine environments, and such a role could also be important in other coastal, marine ecosystems.…”

Section: Discussionmentioning

confidence: 79%

Kelp-Associated Microbes Facilitate Spatial Subsidy in a Detrital-Based Food Web in a Shoreline Ecosystem

et al. 2021

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Microbes are ubiquitous but our knowledge of their effects on consumers is limited in benthic marine systems. Shorelines often form hotspots of microbial and detritivore activity due to the large amounts of detrital macrophytes that are exported from other coastal ecosystems, such as kelp forests, and accumulate in these systems. Shoreline ecosystems therefore provide a useful model system to examine microbial-detritivore interactions. We experimentally test whether bacteria in the biofilm of kelp provide a bottom-up influence on growth and reproductive output of detritivores in shorelines where detrital kelp accumulates, by manipulating the bacterial abundances on kelp (Ecklonia radiata). The growth rates for both male and female amphipods (Allorchestes compressa) were greater in treatments containing bacteria than those in which bacteria were reduced through antibiotic treatment, and this effect was greater for males offered aged kelp. The proportions of ovigerous females were greater when reared on kelp with intact bacteria, indicating a more rapid reproductive development in the presence of more bacteria. Bacterial abundance had little to no influence on nutrient content and palatability of kelp, based on tissue toughness, nitrogen and carbon content and C:N ratio. Thus, the most likely pathway for a microbial effect on detritivores was through feeding on kelp-associated bacteria. Regardless of the pathway, kelp-associated microbes have a strong influence on the fitness of a highly abundant detritivore that feeds preferentially on E. radiata in shoreline systems, and therefore form a hidden trophic step in this “brown” food web and a hotspot of secondary production.

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Detrital Dynamics and Cascading Effects on Supporting Ecosystem Services

Cited by 19 publications

References 225 publications

Warming reverses top-down effects of predators on belowground ecosystem function in Arctic tundra

Warming reverses top-down effects of predators on belowground ecosystem function in Arctic tundra

Interspecific and interpopulation variation in individual diet specialization: Do environmental factors have a role?

Kelp-Associated Microbes Facilitate Spatial Subsidy in a Detrital-Based Food Web in a Shoreline Ecosystem

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