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It is well recognized that within local communities, fluctuations of constituent species over time can alter both aggregate (e.g., total abundance or biomass) and compositional community properties. At broader spatial scales, recent evidence shows how spatial asynchrony can further stabilize aggregate properties at the regional, or metacommunity, scale. Yet, apparent lack of variability in aggregate metacommunity properties can mask changes in metacommunity composition, and a framework acknowledging such dual nature of metacommunity variability is still lacking. Here, we present an approach to characterize metacommunity variability that integrates both aggregate and compositional properties. We demonstrate that the compositional variability of a metacommunity critically depends on the degree of spatial synchrony in the compositional trajectories over time among local communities. We develop two methods, available in the ltmc R package, to quantify such spatial compositional synchrony and apply them to a case study of understory macroalgal communities inhabiting shallow rocky reefs off the coast of Santa Barbara, California. We found that moderate spatial asynchrony reduced variability in aggregate metacommunity biomass, whilst masking synchronous, and potentially destabilizing, compositional variability at the metacommunity scale. These results highlight the need to consider both aspects of metacommunity variability simultaneously in order to fully understand variability over broad spatial scales.
Thomas Lamy; Nathan I. Wisnoski; Riley Andrade; Max C.N. Castorani; Aldo Compagnoni; Nina Lany; Luca Marazzi; Sydne Record; Christopher M. Swan; Jonathan D. Tonkin; Nicole Voelker; Shaopeng Wang; Phoebe L. Zarnetske; Eric R. Sokol. The dual nature of metacommunity variability. 2021, 1 .
AMA StyleThomas Lamy, Nathan I. Wisnoski, Riley Andrade, Max C.N. Castorani, Aldo Compagnoni, Nina Lany, Luca Marazzi, Sydne Record, Christopher M. Swan, Jonathan D. Tonkin, Nicole Voelker, Shaopeng Wang, Phoebe L. Zarnetske, Eric R. Sokol. The dual nature of metacommunity variability. . 2021; ():1.
Chicago/Turabian StyleThomas Lamy; Nathan I. Wisnoski; Riley Andrade; Max C.N. Castorani; Aldo Compagnoni; Nina Lany; Luca Marazzi; Sydne Record; Christopher M. Swan; Jonathan D. Tonkin; Nicole Voelker; Shaopeng Wang; Phoebe L. Zarnetske; Eric R. Sokol. 2021. "The dual nature of metacommunity variability." , no. : 1.
The use and management of single use plastics is a major area of concern for the public, regulatory and business worlds. Focusing on the most commonly occurring consumer plastic items present in European freshwater environments, we identified and evaluated consumer-based actions with respect to their direct or indirect potential to reduce macroplastic pollution in freshwater environments. As the main end users of these items, concerned consumers are faced with a bewildering array of choices to reduce their plastics footprint, notably through recycling or using reusable items. Using a Multi-Criteria Decision Analysis approach, we explored the effectiveness of 27 plastic reduction actions with respect to their feasibility, economic impacts, environmental impacts, unintended social/environmental impacts, potential scale of change and evidence of impact. The top ranked consumer-based actions were identified as: using wooden or reusable cutlery; switching to reusable water bottles; using wooden or reusable stirrers; using plastic free cotton-buds; and using refill detergent/ shampoo bottles. We examined the feasibility of top-ranked actions using a SWOT analysis (Strengths, Weaknesses, Opportunities and Threats) to explore the complexities inherent in their implementation for consumers, businesses, and government to reduce the presence of plastic in the environment.
Luca Marazzi; Steven Loiselle; Lucy G. Anderson; Stephen Rocliffe; Debbie J. Winton. Consumer-based actions to reduce plastic pollution in rivers: A multi-criteria decision analysis approach. PLoS ONE 2020, 15, e0236410 .
AMA StyleLuca Marazzi, Steven Loiselle, Lucy G. Anderson, Stephen Rocliffe, Debbie J. Winton. Consumer-based actions to reduce plastic pollution in rivers: A multi-criteria decision analysis approach. PLoS ONE. 2020; 15 (8):e0236410.
Chicago/Turabian StyleLuca Marazzi; Steven Loiselle; Lucy G. Anderson; Stephen Rocliffe; Debbie J. Winton. 2020. "Consumer-based actions to reduce plastic pollution in rivers: A multi-criteria decision analysis approach." PLoS ONE 15, no. 8: e0236410.
Foundation species provide habitat to other organisms and enhance ecosystem functions, such as nutrient cycling, carbon storage and sequestration, and erosion control. We focus on freshwater wetlands because these ecosystems are often characterized by foundation species; eutrophication and other environmental changes may cause the loss of some of these species, thus severely damaging wetland ecosystems. To better understand how wetland primary producer foundation species support other species and ecosystem functions across environmental gradients, we reviewed ~150 studies in subtropical, boreal, and temperate freshwater wetlands. We look at how the relative dominance of conspicuous and well-documented species (i.e., sawgrass, benthic diatoms and cyanobacteria, Sphagnum mosses, and bald cypress) and the foundational roles they play interact with hydrology, nutrient availability, and exposure to fire and salinity in representative wetlands. Based on the evidence analyzed, we argue that the foundation species concept should be more broadly applied to include organisms that regulate ecosystems at different spatial scales, notably the microscopic benthic algae that critically support associated communities and mediate freshwater wetlands’ ecosystem functioning. We give recommendations on how further research efforts can be prioritized to best inform the conservation of foundation species and of the freshwater wetlands they support.
Luca Marazzi; Evelyn E. Gaiser; Maarten B. Eppinga; Jay P. Sah; Lu Zhai; Edward Castañeda-Moya; Christine Angelini. Why Do We Need to Document and Conserve Foundation Species in Freshwater Wetlands? Water 2019, 11, 265 .
AMA StyleLuca Marazzi, Evelyn E. Gaiser, Maarten B. Eppinga, Jay P. Sah, Lu Zhai, Edward Castañeda-Moya, Christine Angelini. Why Do We Need to Document and Conserve Foundation Species in Freshwater Wetlands? Water. 2019; 11 (2):265.
Chicago/Turabian StyleLuca Marazzi; Evelyn E. Gaiser; Maarten B. Eppinga; Jay P. Sah; Lu Zhai; Edward Castañeda-Moya; Christine Angelini. 2019. "Why Do We Need to Document and Conserve Foundation Species in Freshwater Wetlands?" Water 11, no. 2: 265.
Biological communities often comprise core species that are locally abundant and regionally common. Benthic diatoms are crucial primary producers in wetlands and reflect ecosystem responses to long-term hydrological and nutrient changes, yet few studies explicitly focus on patterns and drivers of diatom core species abundance in these ecosystems. We investigated how benthic diatom core species abundance varies over space, time, and environmental gradients in a major shallow wetland, the Florida Everglades, where environmental gradients and diatom assemblages are spatially structured by water diversion and nutrient loading. We analysed a long-term dataset of species and environmental data collected over 6 locations in 2 major Southern Everglades drainages. We hypothesized that (1) the abundance of 4 diatom core species (present in >90% of the samples with relative abundance >5%) and water depth, benthic algal mat mineral weight and organic content, and mat total phosphorus and total nitrogen would vary more across space than time; and (2) the cumulative diatom core species abundance would increase with decreasing nutrient concentrations and depth. We found that (1) the abundance of 2 of the core species and the environmental conditions varied more between sites than between seasons and years, and (2) the cumulative abundance of the 4 diatom core species increased with oligotrophic and shallow water conditions. This study shows how, on average, the 4 diatom core species comprise ∼82% of the total diatom abundance in the Everglades’ benthic algal mats because these species are adapted to nutrient limitation and water scarcity. Similar dynamics may be at play in other wetlands undergoing hydrological and nutrient changes, thus warranting future work to predict these primary producers’ responses to such changes.
L. Marazzi; Evelyn Gaiser. Long-term changes in spatially structured benthic diatom assemblages in a major subtropical wetland under restoration. Inland Waters 2018, 8, 434 -448.
AMA StyleL. Marazzi, Evelyn Gaiser. Long-term changes in spatially structured benthic diatom assemblages in a major subtropical wetland under restoration. Inland Waters. 2018; 8 (4):434-448.
Chicago/Turabian StyleL. Marazzi; Evelyn Gaiser. 2018. "Long-term changes in spatially structured benthic diatom assemblages in a major subtropical wetland under restoration." Inland Waters 8, no. 4: 434-448.
Nitrogen (N) and phosphorus (P) concentrations and N:P ratios critically influence periphyton productivity and nutrient cycling in aquatic ecosystems. In coastal wetlands, variations in hydrology and water source (fresh or marine) influence nutrient availability, but short-term effects of drying and rewetting and long-term effects of nutrient exposure on periphyton nutrient retention are uncertain. An outdoor microcosm experiment simulated short-term exposure to variation in drying-rewetting frequency on periphyton mat nutrient retention. A 13-year dataset from freshwater marshes of the Florida Everglades was examined for the effect of long-term proximity to different N and P sources on mat-forming periphyton nutrient standing stocks and stoichiometry. Field sites were selected from one drainage with shorter hydroperiod and higher connectivity to freshwater anthropogenic nutrient supplies (Taylor Slough/Panhandle, TS/Ph) and another drainage with longer hydroperiod and higher connectivity to marine nutrient supplies (Shark River Slough, SRS). Total P, but not total N, increased in periphyton mats exposed to both low and high drying-rewetting frequency with respect to the control mats in our experimental microcosm. In SRS, N:P ratios slightly decreased downstream due to marine nutrient supplies, while TS/Ph increased. Mats exposed to short-term drying-rewetting had higher nutrient retention, similar to nutrient standing stocks from long-term field data. Periphyton mat microbial communities may undergo community shifts upon drying-rewetting and chronic exposure to nutrient loads. Additional work on microbial species composition may further explain how periphyton communities interact with drying-rewetting dynamics to influence nutrient cycling and retention in wetlands.
Andres D. Sola; Luca Marazzi; Monica M. Flores; John S. Kominoski; Evelyn E. Gaiser. Short-Term Effects of Drying-Rewetting and Long-Term Effects of Nutrient Loading on Periphyton N:P Stoichiometry. Water 2018, 10, 105 .
AMA StyleAndres D. Sola, Luca Marazzi, Monica M. Flores, John S. Kominoski, Evelyn E. Gaiser. Short-Term Effects of Drying-Rewetting and Long-Term Effects of Nutrient Loading on Periphyton N:P Stoichiometry. Water. 2018; 10 (2):105.
Chicago/Turabian StyleAndres D. Sola; Luca Marazzi; Monica M. Flores; John S. Kominoski; Evelyn E. Gaiser. 2018. "Short-Term Effects of Drying-Rewetting and Long-Term Effects of Nutrient Loading on Periphyton N:P Stoichiometry." Water 10, no. 2: 105.
A few dominant species of plants often disproportionately contribute to primary production; however, dominance has an underappreciated influence on ecosystem processes and functioning. Cascading impacts of dominant species have been documented in ecosystems undergoing eutrophication, but competitive exclusion may also influence dominance structures when limiting nutrients become scarce (i.e., in lakes experiencing oligotrophication) or with exposure to stressors to which few species are adapted (i.e., desiccation stress in wetlands). To predict impacts of widespread changes in nutrients and hydrology on dominance structures in aquatic ecosystems, we need quantitative assessments of dominance of important primary producers, including algae and cyanobacteria, which can regulate other structural and functional properties of ecosystems. We used a highly spatiotemporally resolved (7 years, 165 sites) dataset from the abundant microbial mats of the Florida Everglades to assess how and why the degree of dominance and the identity of dominant taxa vary across nutrient and desiccation gradients. Using algal counts and the dimensions of algal units (cells, coenobia, colonies, and filaments), we measured dominance as relative biovolume. As hypothesized, the relative biovolume of dominant taxa increased and the number of taxa comprising 95% of the biovolume decreased with lower concentrations of limiting nutrient in the mats (phosphorus; P) and higher desiccation stress. Algal taxa that regulate the structural integrity of mats, such as the filamentous, calcium carbonate precipitating cyanobacterium Scytonema sp., strongly influenced these patterns through their tolerance of P scarcity and desiccation. Our indicators and approach can be used to test whether dominance of microscopic primary producers, and other organisms, increases with nutrient scarcity and desiccation stress in other aquatic ecosystems.
L. Marazzi; Evelyn Gaiser; F. A. C. Tobias. Phosphorus scarcity and desiccation stress increase the occurrence of dominant taxa in wetland benthic primary producer communities. Aquatic Ecology 2017, 51, 571 -589.
AMA StyleL. Marazzi, Evelyn Gaiser, F. A. C. Tobias. Phosphorus scarcity and desiccation stress increase the occurrence of dominant taxa in wetland benthic primary producer communities. Aquatic Ecology. 2017; 51 (4):571-589.
Chicago/Turabian StyleL. Marazzi; Evelyn Gaiser; F. A. C. Tobias. 2017. "Phosphorus scarcity and desiccation stress increase the occurrence of dominant taxa in wetland benthic primary producer communities." Aquatic Ecology 51, no. 4: 571-589.
Luca Marazzi; Evelyn E. Gaiser; Vivienne J. Jones; Franco A. C. Tobias; Anson W. Mackay. Algal richness and life‐history strategies are influenced by hydrology and phosphorus in two major subtropical wetlands. Freshwater Biology 2016, 62, 274 -290.
AMA StyleLuca Marazzi, Evelyn E. Gaiser, Vivienne J. Jones, Franco A. C. Tobias, Anson W. Mackay. Algal richness and life‐history strategies are influenced by hydrology and phosphorus in two major subtropical wetlands. Freshwater Biology. 2016; 62 (2):274-290.
Chicago/Turabian StyleLuca Marazzi; Evelyn E. Gaiser; Vivienne J. Jones; Franco A. C. Tobias; Anson W. Mackay. 2016. "Algal richness and life‐history strategies are influenced by hydrology and phosphorus in two major subtropical wetlands." Freshwater Biology 62, no. 2: 274-290.
Luca Marazzi. Okavango Delta - Biodiversity of Microalgae, precious invisible plants. Biodiversity & Ecology 2013, 5, 161 .
AMA StyleLuca Marazzi. Okavango Delta - Biodiversity of Microalgae, precious invisible plants. Biodiversity & Ecology. 2013; 5 ():161.
Chicago/Turabian StyleLuca Marazzi. 2013. "Okavango Delta - Biodiversity of Microalgae, precious invisible plants." Biodiversity & Ecology 5, no. : 161.