Ecosystem consequences of species richness and composition in pond food webs

  title={Ecosystem consequences of species richness and composition in pond food webs},
  author={Amy L Downing and Mathew A. Leibold},
Resolving current concerns about the role of biodiversity on ecosystems calls for understanding the separate roles of changes in species numbers and of composition. Recent work shows that primary productivity often, but not always, saturates with species richness within single trophic levels. However, any interpretation of such patterns must consider that variation in biodiversity is necessarily associated with changes in species composition (identity), and that changes in biodiversity often… 
Comparisons of the relative effects of species composition, species richness, functional group richness, and functional group composition across pond food webs suggest that the roles of species in ecosystems, when considered in a food web context, are often the result of both direct and indirect effects that are difficult to predict.
Fish diversity as a determinant of ecosystem properties across multiple trophic levels
This study links the biodiversity ecosystem function paradigm with food web concepts to improve predictions for conservation and management actions in response to changes in biodiversity.
Effects of fish species richness and assemblage composition on stream ecosystem function
It was found that fish species richness and assemblage composition were important predictors of PPR in stream mesocosms, and the effect of species richness on PPR increased with time, suggesting that richness-related effects might strengthen as the magnitude of community-level interactions increases in ecosystems.
Effects of Trophic Skewing of Species Richness on Ecosystem Functioning in a Diverse Marine Community
It is suggested that trophic skewing of species richness and overall changes in food web topology can influence marine community structure and food web dynamics in complex ways, emphasizing the need for multitrophic approaches to understand the consequences of marine extinctions and invasions.
Species identity drives ecosystem function in a subsidy-dependent coastal ecosystem.
The results provide further evidence that species traits, rather than richness per se, influence ecosystem function most, particularly in detrital-based food webs with high functional redundancy across species, and suggest that loss of large-bodied consumer species could disproportionally impact ecosystem function.
Food-web constraints on biodiversity–ecosystem functioning relationships
  • É. ThébaultM. Loreau
  • Environmental Science
    Proceedings of the National Academy of Sciences of the United States of America
  • 2003
It is shown that plant biomass does not always increase with plant diversity and that changes in biodiversity can lead to complex if predictable changes in ecosystem processes, and that food-web structure can profoundly influence ecosystem properties.
Species loss and the structure and functioning of multitrophic aquatic systems
The results indicate that, at least for aquatic systems, models of single trophic level ecosystems are insufficient for understanding the functional consequences of extinctions.
Experimental evaluation of diversity–productivity relationships in a coral reef fish assemblage
The results suggest that niche complementarity and facilitation are not the most influential drivers of total productivity within this guild of planktivorous fishes, and total productivity may be resilient to declining reef fish biodiversity.
Species richness–variability relationships in multi‐trophic aquatic microcosms
The results suggest that species loss may affect population and community variability differently in multi-trophic versus single trophic level communities, and if this is so, then the mechanisms proposed to underlie the effects of S on community variability in single-Trophic communities may have to be supplemented by those that describe contributions to population stability in order to fully describe the patterns observed in multi -trophic communities.


Environmental warming alters food-web structure and ecosystem function
It is shown using microcosm experiments that extinction risk in warming environments depends on trophic position but remains unaffected by biodiversity, which suggests that high biodiversity buffers against the effects of environmental variation because tolerant species are more likely to be found.
Resource-niche complementarity and autotrophic compensation determines ecosystem-level responses to increased cladoceran species richness
The results show that different mechanisms are important for different combinations of species, and the ability of the prey community to respond to changes of consumer species composition is an important factor in experiments in which consumer species richness is experimentally manipulated.
Biodiversity regulates ecosystem predictability
By manipulating biodiversity in aquatic microbial communities, it is shown that one process, ecosystem respiration, becomes more predictable as biodiversity increases, and analysis of similar patterns extracted from other studies indicates that biodiversity also enhances predictability in terrestrial ecosystems.
Linking biodiversity to ecosystem function: implications for conservation ecology
Little support is found for the hypothesis that there is a strong dependence of ecosystem function on the full complement of diversity within sites, and the conservation community should take a cautious view of endorsing this linkage as a model to promote conservation goals.
Plant diversity and ecosystem productivity: theoretical considerations.
Three simple models of interspecific competitive interactions in communities containing various numbers of randomly chosen species predict that, on average, productivity increases asymptotically with the original biodiversity of a community and show that both species identity and biodiversity simultaneously influence ecosystem functioning.
Declining biodiversity can alter the performance of ecosystems
COMMUNITIES of species and their associated biological, chemical and physical processes, collectively known as ecosystems, drive the Earth's biogeochemical processes1,2. Currently most ecosystems are
The Influence of Functional Diversity and Composition on Ecosystem Processes
Functional composition and functional diversity were the principal factors explaining plant productivity, plant percent nitrogen, plant total nitrogen, and light penetration in grassland plots.
Expert Estimates about Effects of Biodiversity on Ecosystem Processes and Services
The survey suggests caution in reducing ecosystem-level biodiversity, but it also underscores the opportunities for land management that may arise from the recognition of biodiversity effects in ecosystems.
Plant diversity and productivity experiments in european grasslands
Niche complementarity and positive species interactions appear to play a role in generating diversity-productivity relationships within sites in addition to sampling from the species pool.
Producer–decomposer co-dependency influences biodiversity effects
It is shown that algal biomass production varies considerably among microcosms, but that neither algal nor bacterial diversity by itself can explain this variation, and that ecosystem response to changing biodiversity is likely to be more complex than other studies have shown.