| 1. |
- Alsterberg, Christian, 1982, et al.
(författare)
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Consumers mediate the effects of experimental ocean acidification and warming on primary producers.
- 2013
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Ingår i: Proceedings of the National Academy of Science of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 110:21, s. 8603-8608
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Tidskriftsartikel (refereegranskat)abstract
- It is well known that ocean acidification can have profound impacts on marine organisms. However, we know little about the direct and indirect effects of ocean acidification and also how these effects interact with other features of environmental change such as warming and declining consumer pressure. In this study, we tested whether the presence of consumers (invertebrate mesograzers) influenced the interactive effects of ocean acidification and warming on benthic microalgae in a seagrass community mesocosm experiment. Net effects of acidification and warming on benthic microalgal biomass and production, as assessed by analysis of variance, were relatively weak regardless of grazer presence. However, partitioning these net effects into direct and indirect effects using structural equation modeling revealed several strong relationships. In the absence of grazers, benthic microalgae were negatively and indirectly affected by sediment-associated microalgal grazers and macroalgal shading, but directly and positively affected by acidification and warming. Combining indirect and direct effects yielded no or weak net effects. In the presence of grazers, almost all direct and indirect climate effects were nonsignificant. Our analyses highlight that (i) indirect effects of climate change may be at least as strong as direct effects, (ii) grazers are crucial in mediating these effects, and (iii) effects of ocean acidification may be apparent only through indirect effects and in combination with other variables (e.g., warming). These findings highlight the importance of experimental designs and statistical analyses that allow us to separate and quantify the direct and indirect effects of multiple climate variables on natural communities.
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| 2. |
- Alsterberg, Christian, 1982, et al.
(författare)
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Habitat diversity and ecosystem multifunctionality-The importance of direct and indirect effects
- 2017
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 3:2
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Tidskriftsartikel (refereegranskat)abstract
- Ecosystems worldwide are facing habitat homogenization due to human activities. Although it is commonly proposed that such habitat homogenization can have negative repercussions for ecosystem functioning, this question has yet to receive explicit scientific attention. We expand on the framework for evaluating the functional consequences of bio-diversity loss by scaling up from the level of species to the level of the entire habitats. Just as species diversity generally fosters ecosystem functioning through positive interspecies interactions, we hypothesize that different habitats within ecosystems can facilitate each other through structural complementarity and through exchange of material and energy across habitats. We show that experimental ecosystems comprised of a diversity of habitats show higher levels of multiple ecosystem functions than ecosystems with low habitat diversity. Our results demonstrate that the effect of habitat diversity on multifunctionality varies with season; it has direct effects on ecosystem functioning in summer and indirect effects, via changes in species diversity, in autumn, but no effect in spring. We propose that joint consideration of habitat diversity and species diversity will prove valuable for both environmental management and basic research.
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| 3. |
- Alsterberg, Christian, 1982, et al.
(författare)
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Multiple stressors and multifunctionality: limited effects on an illuminated benthic system
- 2014
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Ingår i: Biology Letters. - : The Royal Society. - 1744-9561 .- 1744-957X. ; 10:12
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Tidskriftsartikel (refereegranskat)abstract
- The bulk of experiments that study stressor effects on ecosystem functioning consider only individual functions one at a time, and such narrow focus may well bias our understanding of the overall impact on ecosystem functioning. We used data from six published experiments in which marine illuminated sediment systems were exposed to nutrient enrichment, toxicants, sedimentation and warming, either alone or in combination. Measured functions were primary production, community respiration, inorganic nitrogen and phosphorus fluxes, and autotrophic biomass. We calculated two indices of multifunctionality that simultaneously considered all six functions: (i) a weighted average level of the functions and (ii) the number of functions that simultaneously exceed a critical threshold level. Stressors affected individual functions both positively and negatively, but multifunctionality was generally unaffected by both single and joint stressors. The filtering capacity of coastal illuminated sediment systems thus appears resilient to exposure to moderate levels of multiple stressors, most probably due to the robustness of the benthic microalgal community. We recommend using a multifunctionality approach in future studies on cumulative stressor effects on ecosystem functioning, particularly when considering functions related to ecosystem services.
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| 4. |
- Brunner, Benedikt, et al.
(författare)
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Macroalgae maintain growth outside their observed distributions: Implications for biodiversity-ecosystem functioning at landscape scales
- 2023
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Ingår i: Journal of Ecology. - 0022-0477 .- 1365-2745. ; 111:6, s. 1362-1373
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Tidskriftsartikel (refereegranskat)abstract
- The spatial insurance hypothesis states that at landscape scales with environmental variability between different places, biodiversity increases ecosystem functioning if species respond asynchronously to environmental variation, and they are highest functioning in places where they dominate the relative abundance. Under this hypothesis, observed species turnover between places in a landscape with environmental variation might suggest that species diversity is an important driver of landscape-scale ecosystem functioning. However, the spatial insurance implicitly assumes that species found in one place in the landscape will not be able to maintain high functioning in other places. Given this assumption of the spatial insurance hypothesis, we would predict that species' functioning in monoculture should decline if transplanted to a different place on an environmental gradient, away from where they naturally dominate. If this is the case, we would expect that the loss of one species in one place of the environmental gradient could not be compensated through the establishment of another species in that place. We tested this prediction using a model system of marine macroalgae on intertidal rocky shores on the Swedish west coast. We performed a reciprocal transplant experiment with adult individuals of four fucoid seaweeds that dominate the standing stock biomass at different depths on these shores and monitored their relative growth rate over 2 months. Counter to the assumptions made by the spatial insurance hypothesis, growth rates for three of the four species showed limited responses to being transplanted to different depth zones. Spatial insurance may, hence, play a minor role in sustaining landscape ecosystem functioning in this and other systems. Synthesis. The functional consequences of species loss at landscape scales may not be as obvious as observational studies and ecological models suggest. Consequently, natural patterns of species turnover should not be used directly to argue for the role of biodiversity at landscape scales. Instead, how species may or may not be able to compensate for the loss of other species is a critical aspect if we are to understand how changes in biodiversity at the landscape scale affect ecosystem functioning.
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| 5. |
- Byrnes, J. E. K., et al.
(författare)
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Investigating the relationship between biodiversity and ecosystem multifunctionality: Challenges and solutions
- 2014
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Ingår i: Methods in Ecology and Evolution. - 2041-210X. ; 5:2, s. 111-124
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Tidskriftsartikel (refereegranskat)abstract
- Summary: Extensive research shows that more species-rich assemblages are generally more productive and efficient in resource use than comparable assemblages with fewer species. But the question of how diversity simultaneously affects the wide variety of ecological functions that ecosystems perform remains relatively understudied. It presents several analytical and empirical challenges that remain unresolved. In particular, researchers have developed several disparate metrics to quantify multifunctionality, each characterizing different aspects of the concept and each with pros and cons. We compare four approaches to characterizing multifunctionality and its dependence on biodiversity, quantifying (i) magnitudes of multiple individual functions separately, (ii) the extent to which different species promote different functions, (iii) the average level of a suite of functions and (iv) the number of functions that simultaneously exceeds a critical threshold. We illustrate each approach using data from the pan-European BIODEPTH experiment and the R multifunc package developed for this purpose, evaluate the strengths and weaknesses of each approach and implement several methodological improvements. We conclude that an extension of the fourth approach that systematically explores all possible threshold values provides the most comprehensive description of multifunctionality to date. We outline this method and recommend its use in future research. © 2013 British Ecological Society.
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| 6. |
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| 7. |
- Duffy, J. E., et al.
(författare)
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Biodiversity mediates top-down control in eelgrass ecosystems: a global comparative-experimental approach
- 2015
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 18:7, s. 696-705
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Tidskriftsartikel (refereegranskat)abstract
- Nutrient pollution and reduced grazing each can stimulate algal blooms as shown by numerous experiments. But because experiments rarely incorporate natural variation in environmental factors and biodiversity, conditions determining the relative strength of bottom-up and top-down forcing remain unresolved. We factorially added nutrients and reduced grazing at 15 sites across the range of the marine foundation species eelgrass (Zostera marina) to quantify how top-down and bottom-up control interact with natural gradients in biodiversity and environmental forcing. Experiments confirmed modest top-down control of algae, whereas fertilisation had no general effect. Unexpectedly, grazer and algal biomass were better predicted by cross-site variation in grazer and eelgrass diversity than by global environmental gradients. Moreover, these large-scale patterns corresponded strikingly with prior small-scale experiments. Our results link global and local evidence that biodiversity and top-down control strongly influence functioning of threatened seagrass ecosystems, and suggest that biodiversity is comparably important to global change stressors.
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| 8. |
- Eklöf, Johan, 1978, et al.
(författare)
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Community-level effects of rapid experiment warming and consumer loss outweigh effects of rapid ocean acidification.
- 2015
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Ingår i: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 124:8, s. 1040-1049
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Tidskriftsartikel (refereegranskat)abstract
- Climate change and consumer loss simultaneously affect marine ecosystems, but we have limited understanding of the relative importance of these factors and the interactions between them. Moreover, effects of environmental change are mediated by organism traits or life histories, which determine their sensitivity. Yet, trait-based analyses have rarely been used to understand the effects of climate change, especially in the marine environment. Here we used a five-week mesocosm experiment to assess the single and interactive effects of 1) rapid ocean warming, 2) rapid ocean acidification, and 3) simulated consumer loss, on the diversity and composition of macrofauna communities in eelgrass Zostera marina beds. Experimental warming (ambient versus + 3.2°C) and loss of a key consumer (the omnivorous crustacean, Gammarus locusta) both increased macrofauna richness and abundance, and altered overall species trait distributions and life history composition. Warming and consumer-loss favored poorly defended epifaunal crustaceans (tube-building amphipods), and species that brood their offspring. We suggest these organisms were favored because warming and consumer-loss caused increased metabolism, food supply and, potentially, settling substrate, and lowered predation pressure from the omnivorous G. locusta. Importantly, we found no single, or interactive, effects of the rapid ocean acidification (ambient versus −0.35 pH units). We suggest this result reflects natural variability in the native habitat and, potentially, the short duration of the experiment: organisms in these communities routinely experience rapid diurnal pH fluctuations that exceed the mean ocean acidification predicted for the coming century (and used in our experiments). In summary, our study indicates that macrofauna in shallow vegetated ecosystems will be significantly more affected by rapid warming and consumer diversity loss than by rapid ocean acidification.
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| 9. |
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| 10. |
- Eklöf, Johan, 1978, et al.
(författare)
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Experimental climate change weakens the insurance effect of biodiversity
- 2012
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 15:8, s. 864-872
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Tidskriftsartikel (refereegranskat)abstract
- Ecosystems are simultaneously affected by biodiversity loss and climate change, but we know little about how these factors interact. We predicted that climate warming and CO 2-enrichment should strengthen trophic cascades by reducing the relative efficiency of predation-resistant herbivores, if herbivore consumption rate trades off with predation resistance. This weakens the insurance effect of herbivore diversity. We tested this prediction using experimental ocean warming and acidification in seagrass mesocosms. Meta-analyses of published experiments first indicated that consumption rate trades off with predation resistance. The experiment then showed that three common herbivores together controlled macroalgae and facilitated seagrass dominance, regardless of climate change. When the predation-vulnerable herbivore was excluded in normal conditions, the two resistant herbivores maintained top-down control. Under warming, however, increased algal growth outstripped control by herbivores and the system became algal-dominated. Consequently, climate change can reduce the relative efficiency of resistant herbivores and weaken the insurance effect of biodiversity.
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| 11. |
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| 12. |
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| 13. |
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| 14. |
- Gamfeldt, Lars, 1975, et al.
(författare)
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Biodiversity effects on aquatic ecosystem functioning - maturation of a new paradigm
- 2008
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Ingår i: International Review of Hydrobiology. ; 93:4-5, s. 550-564
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Tidskriftsartikel (refereegranskat)abstract
- Starting with the publication of some influential studies in the early 1990’s, the topic of biodiversity and ecosystem functioning has emerged as a major field within ecological research. Within this framework, the diversity of genotypes, species and functional groups are considered as explanatory variables of ecosystem functions rather than response variables of factors such as productivity and disturbance. Biodiversity-ecosystem functioning research has received considerable attention, and new publications are emerging at a high pace. Both the validity of experimental approaches and the way the results may be extrapolated to natural systems have, however, been widely discussed. The width of the debate regarding whether or not biodiversity is important for ecosystem functioning have encouraged many scientists to refine both experiments and theory, as well as develop novel methods to analyse the relationship between diversity and functioning. Aquatic ecologists have contributed greatly to the evolution of ideas and concepts within the field. In this review, we discuss how the paradigm that biodiversity is an important factor for the functioning of aquatic ecosystems is currently maturing with more realistic studies embracing both new and innovative approaches. We also suggest fruitful areas for future research.
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| 15. |
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| 16. |
- Gamfeldt, Lars, 1975, et al.
(författare)
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Higher levels of multiple ecosystem services are found in forests with more tree species
- 2013
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Forests are of major importance to human society, contributing several crucial ecosystem services. Biodiversity is suggested to positively influence multiple services but evidence from natural systems at scales relevant to management is scarce. Here, across a scale of 400,000km2, we report that tree species richness in production forests shows positive to positively hump-shaped relationships with multiple ecosystem services. These include production of tree biomass, soil carbon storage, berry production and game production potential. For example, biomass production was approximately 50% greater with five than with one tree species. In addition, we show positive relationships between tree species richness and proxies for other biodiversity components. Importantly, no single tree species was able to promote all services, and some services were negatively correlated to each other. Management of production forests will therefore benefit from considering multiple tree species to sustain the full range of benefits that the society obtains from forests.
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| 17. |
- Gamfeldt, Lars, 1975, et al.
(författare)
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Increasing intraspecific diversity enhances settling success in a marine invertebrate
- 2005
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Ingår i: Ecology. - : Wiley. - 0012-9658. ; 86:12, s. 3219-3224
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Tidskriftsartikel (refereegranskat)abstract
- Theoretical and empirical research during the last decade suggests that increasing species richness often enhances ecosystem processes Such as productivity, nutrient cycling. or resistance to disturbance. By analogous reasoning, it can be hypothesized that genetic diversity within species will have equivalent effects; however, this hypothesis has rarely been tested. We present experimental support for the positive effects of intraspecific diversity on a key trait: larval settlement in a marine invertebrate, the barnacle Balanus improvisus. Varying within-species diversity levels of an animal over nine experiments, We found increasing larval settlement with increasing diversity (one, two, or three parental broods). Possible mechanisms explaining this pattern include: (1) facilitation of gregarious response through the presence of founder genotypes, and (2) ensuring genetic complementarity to increase future reproductive potential. Our results indicate that changing intraspecific genetic diversity could have hitherto unrecognized community-scale implications for larval recruitment and space occupancy.
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| 18. |
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| 19. |
- Gamfeldt, Lars, 1975, et al.
(författare)
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Marine biodiversity and ecosystem functioning: What's known and what's next?
- 2015
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Ingår i: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 124:3, s. 252-265
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Tidskriftsartikel (refereegranskat)abstract
- Marine ecosystems are experiencing rapid and pervasive changes in biodiversity and species composition. Understanding the ecosystem consequences of these changes is critical to effectively managing these systems. Over the last several years, numerous experimental manipulations of species richness have been performed, yet existing quantitative syntheses have focused on a just a subset of processes measured in experiments and, as such, have not summarized the full data available from marine systems. Here, we present the results of a meta-analysis of 110 marine experiments from 42 studies that manipulated the species richness of organisms across a range of taxa and trophic levels and analysed the consequences for various ecosystem processes (categorised as production, consumption or biogeochemical fluxes). Our results show that, generally, mixtures of species tend to enhance levels of ecosystem function relative to the average component species in monoculture, but have no effect or a negative effect on functioning relative to the 'highest- performing' species. These results are largely consistent with those from other syntheses, and extend conclusions to ecological functions that are commonly measured in the marine realm (e.g. nutrient release from sediment bioturbation). For experiments that manipulated three or more levels of richness, we attempted to discern the functional form of the biodiversity-ecosystem functioning relationship. We found that, for response variables related to consumption, a power-function best described the relationship, which is also consistent with previous findings. However, we identified a linear relationship between richness and production. Combined, our results suggest that changes in the number of species will, on average, tend to alter the functioning of marine ecosystems. We outline several research frontiers that will allow us to more fully understand how, why, and when diversity may drive the functioning of marine ecosystems. Synthesis The oceans host an incredible number and variety of species. However, human activities are driving rapid changes in the marine environment. It is imperative we understand ecosystem consequences of any associated loss of species. We summarized data from 110 experiments that manipulated species diversity and evaluated resulting changes to a range of ecosystem responses. We show that losing species, on average, decreases productivity, growth, and a myriad of other processes related to how marine organisms capture and utilize resources. Finally, we suggest that the loss of species may have stronger consequences for some processes than others.
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| 20. |
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| 21. |
- Gamfeldt, Lars, 1975, et al.
(författare)
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Revisiting the biodiversity-ecosystem multifunctionality relationship
- 2017
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Ingår i: Nature Ecology and Evolution. - : Springer Science and Business Media LLC. - 2397-334X. ; 1:7
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Tidskriftsartikel (refereegranskat)abstract
- A recent and prominent claim for the value of biodiversity is its importance for sustaining multiple ecosystem functions. The general idea is intuitively appealing: since all species are to some extent unique, each will be important for a different set of functions. Therefore, as more functions are considered, a greater diversity of species is necessary to sustain all functions simultaneously. However, we show here that the relationship between biodiversity and ecosystem functioning does not change with the number of functions considered. Biodiversity affects the level of multifunctionality via non-additive effects on individual functions, and the effect on multifunctionality equals the average effect on single functions. These insights run counter to messages in the literature. In the light of our simulations, we present limitations and pitfalls with current methods used to study biodiversity-multifunctionality, which together provide a perspective for future studies. © 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.
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| 22. |
- Gamfeldt, Lars, 1975, et al.
(författare)
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Scaling-up the biodiversity-ecosystem functioning relationship: the effect of environmental heterogeneity on transgressive overyielding
- 2023
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Ingår i: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 2023:3
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Tidskriftsartikel (refereegranskat)abstract
- Knowledge of how biodiversity sustains ecosystem function comes predominantly from studies focused on small spatial scales. Thus, we know relatively little about the role of biodiversity at larger scales of space and time where habitats become increasingly heterogeneous. Efforts to upscale the relationship between biodiversity and function have yielded inconclusive results. Given that increasing habitat heterogeneity is a ubiquitous consequence of increasing spatial scale, we asked: as habitat heterogeneity increases, can single species continue to maintain ecosystem function? Or, does transgressive overyielding (functioning of species mixture divided by the functioning of the highest functioning single species) change with habitat heterogeneity? We addressed this using a combination of computer simulations, an experiment and a meta-analysis. The three parts followed the same rationale: habitat heterogeneity was increased by aggregating local habitats with different conditions into larger and more heterogeneous landscapes. The computer simulations showed that, on average, transgressive overyielding increased with habitat heterogeneity because monoculture functioning decreased with habitat heterogeneity. We tested this expectation experimentally by varying the strain richness from one to five species across 10800 bacterial communities in five different habitats defined by sub-inhibitory concentrations of antibiotics. On average, the experimental results concurred with the simulations. We tested the generality of this result using a meta-analysis of 26 published experiments that manipulated habitat conditions and species richness. This confirmed that transgressive overyielding tended to increase with habitat heterogeneity but only when species were specialised to different habitats and were not inhibited in mixtures by negative species interactions. This was not the case in several experiments used in our meta-analysis where one species maximised functioning across all habitats, contrary to the assumptions of many ecological models. Our results illustrate the importance of biodiversity at larger spatial scales with more heterogeneity but also highlights contingencies that this pattern depends on.
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| 23. |
- Gamfeldt, Lars, 1975, et al.
(författare)
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Species richness changes across two trophic levels simultaneously affect prey and consumer biomass
- 2005
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 8:7, s. 696-703
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Tidskriftsartikel (refereegranskat)abstract
- Increasing species richness of primary producers or consumers is proposed to increase primary and secondary production; however, the consequences of biodiversity change across trophic levels has been poorly investigated. We used a controlled marine microbial system to investigate the effects of simultaneous changes in biodiversity of consumer and prey species. Consumer (ciliates) and prey (algae) richness and identity were manipulated independently in a complete factorial design. The results showed clear biodiversity effects of both consumers and prey, within and across trophic levels. We found reduced prey and increased consumer biomass with increased consumer richness, with the most diverse prey assemblage supporting the highest biomass of consumers at the highest richness of consumers. Increasing prey richness did not increase resistance to consumption when consumers were present. Instead, our results indicated enhanced energy transfer with simultaneous increasing richness of consumers and prey.
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| 24. |
- Gamfeldt, Lars, 1975, et al.
(författare)
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The Role of Biodiversity for the Functioning of Rocky Reef Communities
- 2009
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Ingår i: Marine Hard Bottom Communities. - Berlin : Springer. - 9783540927037
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Many important classic studies elucidating these local-scale processes have been conducted in marine hard-bottom communities (e.g. Kitching and Ebling 1961 ; Paine 1966 ; Menge and Sutherland 1976 ; Connell 1978 ; Lubchenco 1978 ; Sousa 1979 ; Fletcher 1987) . These studies and subsequent work have shown that diversity in rocky intertidal and subtidal systems is regulated by a combination of abiotic (e.g. disturbance, productivity, nutrient availability) and biotic (e.g. competition, consumption) processes (Worm et al. 2002 ; Nielsen 2003 ; Graham 2004 ; Bracken and Nielsen 2004 ; see Part II of this book). However, the organisms inhabiting these ecosystems are not only influenced by the performance of the systems—they also, in part, determine it. Growing evidence from a variety of systems indicates that organisms, by virtue of their roles in mediating ecosystem performance, influence the rates of biogeochemical processes, stability, and other attributes of the ecosystems in which they live (Naeem 2002 ; Kinzig et al. 2002 ; Cardinale et al. 2006) . Because of the unique roles that different organisms play in mediating ecosystem performance, there is a growing awareness that the diversity of organisms in a system can influence that system’s performance (reviewed in Hooper et al. 2005) . Recent studies have illustrated several key ways in which organisms inhabiting temperate and tropical reefs—and, by extension, the diversity of those organisms—influence the performance of marine ecosystems (reviewed in Worm et al. 2006) . Below, we review studies from hard-bottom marine ecosystems and provide suggestions for future research into the functional roles of marine biodiversity in temperate and tropical hard-bottom communities. Accumulated evidence and theoretical reasoning suggest that the diversity of benthic communities may be an important property for the functioning of these ecosystems.
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| 25. |
- Gruner, D. S., et al.
(författare)
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Effects of experimental warming on biodiversity depend on ecosystem type and local species composition
- 2017
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Ingår i: Oikos. - : Wiley. - 0030-1299. ; 126:1, s. 8-17
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Tidskriftsartikel (refereegranskat)abstract
- Climatic warming is a primary driver of change in ecosystems worldwide. Here, we synthesize responses of species richness and evenness from 187 experimental warming studies in a quantitative meta-analysis. We asked 1) whether effects of warming on diversity were detectable and consistent across terrestrial, freshwater and marine ecosystems, 2) if effects on diversity correlated with intensity, duration, and experimental unit size of temperature change manipulations, and 3) whether these experimental effects on diversity interacted with ecosystem types. Using multilevel mixed linear models and model averaging, we also tested the relative importance of variables that described uncontrolled environmental variation and attributes of experimental units. Overall, experimental warming reduced richness across ecosystems (mean log-response ratio = -0.091, 95% bootstrapped CI: -0.13, -0.05) representing an 8.9% decline relative to ambient temperature treatments. Richness did not change in response to warming in freshwater systems, but was more strongly negative in terrestrial (-11.8%) and marine (-10.5%) experiments. In contrast, warming impacts on evenness were neutral overall and in aquatic systems, but weakly negative on land (7.6%). Intensity and duration of experimental warming did not explain variation in diversity responses, but negative effects on richness were stronger in smaller experimental units, particularly in marine systems. Model-averaged parameter estimation confirmed these main effects while accounting for variation in latitude, ambient temperature at the sites of manipulations, venue (field versus lab), community trophic type, and whether experiments were open or closed to colonization. These analyses synthesize extensive experimental evidence showing declines in local richness with increased temperature, particularly in terrestrial and marine communities. However, the more variable effects of warming on evenness were better explained by the random effect of site identity, suggesting that effects on species' relative abundances were contingent on local species composition.
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