| 1. |
- Rodil, Iván F., et al.
(författare)
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Macrofauna communities across a seascape of seagrass meadows : environmental drivers, biodiversity patterns and conservation implications
- 2021
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Ingår i: Biodiversity and Conservation. - : Springer Science and Business Media LLC. - 0960-3115 .- 1572-9710. ; :30, s. 3023-3043
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Tidskriftsartikel (refereegranskat)abstract
- Similar to other coastal biogenic habitats (e.g. tidal marshes, kelp forests, mangroves and coral reefs), a key function of seagrass meadows is the enhancement of biodiversity. Variability at multiple spatial scales is a driver of biodiversity, but our understanding of the response of macrofauna communities to variability of seagrass meadows is limited. We examined the macrofauna community structure (abundance and biomass) and diversity patterns (α- and β-diversity) across a seascape gradient of eleven seagrass meadows differing in the number, composition and density of plant species. The variability of the macrobenthic communities was regulated by a combination of sedimentary (mainly for the infauna) and macrophyte (mainly for the epifauna) predictors. We demonstrate that the natural occurrence of drifting algae trapped in the aboveground complexity of the meadows benefits seagrass macrofauna. Seagrass-associated macrofauna showed a clear increase in abundance and α-diversity metrics with increasing habitat complexity attributes (i.e. shoot density, plant biomass and canopy height). Furthermore, partitioning of β-diversity (i.e. the variation of species composition between sites) implied the replacement of some species by others between sites (i.e. spatial turnover) instead of a process of species loss (or gain) from site to site (i.e. nestedness). Therefore, the enhancement of macrofauna diversity across an increasing gradient of seagrass complexity, and the dominance of the turnover component suggest that devoting conservation efforts on many different types of meadows, including the less diverse, should be a priority for coastal habitat-management.
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| 2. |
- Rodil, Iván F., et al.
(författare)
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Positive contribution of macrofaunal biodiversity to secondary production and seagrass carbon metabolism
- 2022
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Ingår i: Ecology. - : Wiley. - 0012-9658 .- 1939-9170. ; 103:4
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Tidskriftsartikel (refereegranskat)abstract
- Coastal vegetated habitats such as seagrasses are known to play a critical role in carbon cycling and the potential to mitigate climate change, as blue carbon habitats have been repeatedly highlighted. However, little information is known about the role of associated macrofauna communities on the dynamics of critical processes of seagrass carbon metabolism (e.g., respiration, turnover, and production). We conducted a field study across a spatial gradient of seagrass meadows involving variable environmental conditions and macrobenthic diversity to investigate (1) the relationship between macrofauna biodiversity and secondary production (i.e., consumer incorporation of organic matter per time unit), and (2) the role of macrofauna communities in seagrass organic carbon metabolism (i.e., respiration and primary production). We show that, although several environmental factors influence secondary production, macrofauna biodiversity controls the range of local seagrass secondary production. We demonstrate that macrofauna respiration rates were responsible for almost 40% of the overall seafloor community respiration. Macrofauna represented on average >25% of the total benthic organic C stocks, high secondary production that is likely to become available to upper trophic levels of the coastal food web. Our findings support the role of macrofauna biodiversity in maintaining productive ecosystems, implying that biodiversity loss due to ongoing environmental change yields less productive seagrass ecosystems. Therefore, the assessment of carbon dynamics in coastal habitats should include associated macrofauna biodiversity elements if we aim to obtain robust estimates of global carbon budgets required to implement management actions for the sustainable functioning of the world's coasts.
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| 3. |
- Cheung, Henry Lok Shan, et al.
(författare)
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Denitrification, anammox, and DNRA in oligotrophic continental shelf sediments
- 2024
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Ingår i: Limnology and Oceanography. - 1939-5590 .- 0024-3590.
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Tidskriftsartikel (refereegranskat)abstract
- Continental shelf sediments are considered hotspots for nitrogen (N) removal. While most investigations have quantified denitrification in shelves receiving large amounts of anthropogenic nutrient supply, we lack insight into the key drivers of N removal on oligotrophic shelves. Here, we measured rates of N removal through denitrification and anammox by the revised-isotope pairing technique (r-IPT) along the Northeastern New Zealand shelf. Denitrification dominated total N2 production at depths between 30 and 128 m with average rates (± SE) ranging from 65 ± 28 to 284 ± 72 μmol N m−2 d−1. N2 production by anammox ranged from 3 ± 1 to 28 ± 11 μmol N m−2 d−1 and accounted for 2–19% of total N2 production. DNRA was negligible in these oligotrophic settings. Parallel microbial community analysis showed that both Proteobacteria and Planctomycetota were key taxa driving denitrification. Denitrification displayed a negative correlation with oxygen penetration depth, and a positive correlation with macrofauna abundance. Our denitrification rates were comparable to oligotrophic shelves from the Arctic, but were lower than those from nutrient-rich Pacific and Atlantic shelves. Based on our results and existing IPT measurements, the global shelf denitrification rate was reassessed to be 53.5 ± 8.1 Tg N yr−1, equivalent to 20 ± 2% of marine N removal. We suggest that previous estimates of global shelf N loss might have been overestimated due to sampling bias toward areas with high N loads in the Northern Hemisphere.
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| 4. |
- Cummings, Vonda J., et al.
(författare)
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Linking Ross Sea Coastal Benthic Communities to Environmental Conditions : Documenting Baselines in a Spatially Variable and Changing World
- 2018
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Ingår i: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the functionality of marine benthic ecosystems, and how they are influenced by their physical environment, is fundamental to realistically predicting effects of future environmental change. The Antarctic faces multiple environmental pressures associated with greenhouse gas emissions, emphasizing the need for baseline information on biodiversity and the bio-physical processes that influence biodiversity. We describe a survey of shallow water benthic communities at eight Ross Sea locations with a range of environmental characteristics. Our analyses link coastal benthic community composition to seafloor habitat and sedimentary parameters and broader scale features, at locations encompassing considerable spatial extent and variation in environmental characteristics (e.g., seafloor habitat, sea ice conditions, hydrodynamic regime, light). Our aims were to: (i) document existing benthic communities, habitats and environmental conditions against which to assess future change, (ii) investigate the relationships between environmental and habitat characteristics and benthic community structure and function, and (iii) determine whether these relationships were dependent on spatial extent. A very high percentage (>95%) of the between-location variability in macro- or epifaunal community composition was explainable using multi-scale environmental variables. The explanatory power varied depending on the scale of influence of the environmental variables measured (fine and medium-scale habitat, broad scale), and with community type. However, the inclusion of parameters at all scales produced the most powerful model for both communities. Ice duration, ice thickness and snow cover were important broad scale variables identified that directly relate to climate change. Even when using only habitat-scale variables, extending the spatial scale of the study from three locations covering 32 km to eight locations covering ~340 km increased the degree of explanatory power from 18–32 to 64–78%. The increase in explanatory power with spatial extent lends weight to the possibility of using an indirect “space for time” substitution approach for future predictions of the effects of change on these coastal marine ecosystems. Given the multiple and interacting drivers of change in Antarctic coastal ecosystems a multidisciplinary, long term, repeated observation approach will be vital to both improve and test predictions of how coastal communities will respond to environmental change.
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| 5. |
- Gladstone-Gallagher, Rebecca V., et al.
(författare)
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Identifying “vital attributes” for assessing disturbance–recovery potential of seafloor communities
- 2021
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 11:11, s. 6091-6103
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Tidskriftsartikel (refereegranskat)abstract
- Despite a long history of disturbance-recovery research, we still lack a generalizable understanding of the attributes that drive community recovery potential in seafloor ecosystems. Marine soft-sediment ecosystems encompass a range of heterogeneity from simple low-diversity habitats with limited biogenic structure, to species-rich systems with complex biogenic habitat structure. These differences in biological heterogeneity are a product of natural conditions and disturbance regimes. To search for unifying attributes, we explore whether a set of simple traits can characterize community disturbance-recovery potential using seafloor patch-disturbance experiments conducted in two different soft-sediment landscapes. The two landscapes represent two ends of a spectrum of landscape biotic heterogeneity in order to consider multi-scale disturbance-recovery processes. We consider traits at different levels of biological organization, from the biological traits of individual species, to the traits of species at the landscape scale associated with their occurrence across the landscape and their ability to be dominant. We show that in a biotically heterogeneous landscape (Kawau Bay, New Zealand), seafloor community recovery is stochastic, there is high species turnover, and the landscape-scale traits are good predictors of recovery. In contrast, in a biotically homogeneous landscape (Baltic Sea), the options for recovery are constrained, the recovery pathway is thus more deterministic and the scale of recovery traits important for determining recovery switches to the individual species biological traits within the disturbed patch. Our results imply that these simple, yet sophisticated, traits can be effectively used to characterize community recovery potential and highlight the role of landscapes in providing resilience to patch-scale disturbances.
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| 6. |
- Gladstone-Gallagher, Rebecca V., et al.
(författare)
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Social-ecological connections across land, water, and sea demand a reprioritization of environmental management
- 2022
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Ingår i: Elementa. - : University of California Press. - 2325-1026. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Despite many sectors of society striving for sustainability in environmental management, humans often fail to identify and act on the connections and processes responsible for social–ecological tipping points. Part of the problem is the fracturing of environmental management and social–ecological research into ecosystem domains (land, freshwater, and sea), each with different scales and resolution of data acquisition and distinct management approaches. We present a perspective on the social–ecological connections across ecosystem domains that emphasize the need for management reprioritization to effectively connect these domains. We identify critical nexus points related to the drivers of tipping points, scales of governance, and the spatial and temporal dimensions of social–ecological processes. We combine real-world examples and a simple dynamic model to illustrate the implications of slow management responses to environmental impacts that traverse ecosystem domains. We end with guidance on management and research opportunities that arise from this cross-domain lens to foster greater opportunity to achieve environmental and sustainability goals.
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