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Tjeerd J Bouma - One of the best experts on this subject based on the ideXlab platform.
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Ecosystem Engineering creates a new path to resilience in plants with contrasting growth strategies.
Oecologia, 2019Co-Authors: Laura M. Soissons, Peter M. J. Herman, Marieke M. Van Katwijk, Qiuying Han, Tom Ysebaert, Tjeerd J BoumaAbstract:Plant species can be characterized by different growth strategies related to their inherent growth and recovery rates, which shape their responses to stress and disturbance. Ecosystem Engineering, however, offers an alternative way to cope with stress: modifying the environment may reduce stress levels. Using an experimental study on two seagrass species with contrasting traits, the slow-growing Zostera marina vs. the fast-growing Zostera japonica, we explored how growth strategies versus Ecosystem Engineering may affect their resistance to stress (i.e. addition of organic material) and recovery from disturbance (i.e. removal of above-ground biomass). Ecosystem Engineering was assessed by measuring sulphide levels in the sediment porewater, as seagrass plants can keep sulphide levels low by aerating the rhizosphere. Consistent with predictions, we observed that the fast-growing species had a high capacity to recover from disturbance. It was also more resistant to stress and still able to maintain high standing stock with increasing stress levels because of its Ecosystem Engineering capacity. The slow-growing species was not able to maintain its standing stock under stress, which we ascribe to a weak capacity for Ecosystem Engineering regarding this particular stress. Overall, our study suggests that the combination of low-cost investment in tissues with Ecosystem Engineering to alleviate stress creates a new path in the growth trade-off between investment in strong tissues or fast growth. It does so by being both fast in recovery and more resistant. As such low-cost Ecosystem Engineering may occur in more species, we argue that it should be considered in assessing plant resilience.
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large scale Ecosystem Engineering by flamingos and fiddler crabs on west african intertidal flats promote joint food availability
Oikos, 2019Co-Authors: Elhacen Mohamed Elhacen, Tjeerd J Bouma, Puck Oomen, Theunis Piersma, Han OlffAbstract:Although the Ecosystem Engineering concept is well established in ecology, cases of joint Engineering by multiple species at large scales remain rare. Here, we combine observational studies and exclosure experiments to investigate how co-occurring greater flamingos Phoenicopterus roseus and fiddler crabs Uca tangeri promote their own and each other's food availability by creating a spatially complex mosaic of depressions (bowls, gullies) and hummocks (plateaus, mounds) in the intertidal zone. This results in a mosaic of microhabitats with different tidal inundation regimes. These microhabitats are spatially organized with labyrinth-like patterns in the high intertidal zone and spotted patterns in the lower intertidal, both of which likely arise from biophysical interactions between these organisms and hydrodynamic forces. We show that the resulting spatial complexity is vital for biofilm production. The depression microhabitats were wetter and richer in organic matter and biofilms compared with hummocks. Excluding flamingos and crabs resulted in an increase in biofilm biomass over the shorter term (six months), but a decrease over the longer term (after one year). Moreover, our results strongly suggest that these biogeomorphological microhabitats in the mosaics were maintained by the feeding activities of flamingos and to a lesser extent crabs. During a period of flamingo exclusion, all the spotted patterns filled up with sediment, while the exclusion of crabs led to gradual sediment accumulation in the labyrinth-like patterns. Collectively, these findings provide empirical evidence for large-scale joint promotion of food availability by multiple taxa in a marine Ecosystem.
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The role of patch size in Ecosystem Engineering capacity: a case study of aquatic vegetation
Aquatic Sciences, 2019Co-Authors: Sofia Licci, Tjeerd J Bouma, Heidi Nepf, Cécile Delolme, Pierre Marmonier, Sara PuijalonAbstract:Submerged aquatic plants are Ecosystem engineers that are able to modify their habitat. However, the role of patch size in the Engineering capacity of aquatic plants has not yet been fully investigated, while it could be essential for elucidating the consequences of plant presence. Our objectives were to investigate the effects of patch size on plant-flow-sediment interactions in lotic Ecosystems and to determine whether these effects differed according to environmental characteristics. We performed in situ measurements of velocity and grain size along natural patches of increasing length (L) at two sites presenting different flow and sediment characteristics. Our results indicated that a minimum patch size was needed to induce in-patch reduction of the time averaged velocity component in the flow direction (i.e. streamwise velocity) and fine sediment accumulation. Streamwise velocity decreased linearly with L independently of the site conditions. The sediment texture was instead dependent on site conditions: for the site characterized by higher velocity and coarser sediment, the sediment grain size exponentially decreased with L, reaching a minimum value at L ≥ 1.0 m, while for the site characterized by lower velocity and finer sediment, it reached a minimum value already at L > 0.3 m. This study demonstrated that a minimal patch size is required to trigger the Ecosystem Engineering capacity of aquatic plant patches in lotic environments and that this capacity increases with patch length. Small patches induce little to no modification of the physical habitat, with possible negative feedbacks for plants. With increasing patch size, the habitat modifications induced by plants become more important, potentially triggering positive feedbacks for plants.
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effects of temporal fluctuation in population processes of intertidal lanice conchilega pallas 1766 aggregations on its Ecosystem Engineering
Estuarine Coastal and Shelf Science, 2017Co-Authors: Renata Mamede Da Silva Alves, Tjeerd J Bouma, Jan Vanaverbeke, Jeanmarc Guarini, Magda Vincx, Carl Van ColenAbstract:Abstract Ecosystem engineers contribute to Ecosystem functioning by regulating key environmental attributes, such as habitat availability and sediment biogeochemistry. While autogenic engineers can increase habitat complexity passively and provide physical protection to other species, allogenic engineers can regulate sediment oxygenation and biogeochemistry through bioturbation and/or bioirrigation. Their effects rely on the physical attributes of the engineer and/or its biogenic constructs, such as abundance and/or size. The present study focused on tube aggregations of a sessile, tube-building polychaete that engineers marine sediments, Lanice conchilega. Its tube aggregations modulate water flow by dissipating energy, influencing sedimentary processes and increasing particle retention. These effects can be influenced by temporal fluctuations in population demographic processes. Presently, we investigated the relationship between population processes and Ecosystem Engineering through an in-situ survey (1.5 years) of L. conchilega aggregations at the sandy beach of Boulogne-sur-Mer (France). We (1) evaluated temporal patterns in population structure, and (2) investigated how these are related to the Ecosystem Engineering of L. conchilega on marine sediments. During our survey, we assessed tube density, demographic structure, and sediment properties (surficial chl-a, EPS, TOM, median and mode grain size, sorting, and mud and water content) on a monthly basis for 12 intertidal aggregations. We found that the population was mainly composed by short-lived (6–10 months), small-medium individuals. Mass mortality severely reduced population density during winter. However the population persisted, likely due to recruits from other populations, which are associated to short- and long-term population dynamics. Two periods of recruitment were identified: spring/summer and autumn. Population density was highest during the spring recruitment and significantly affected several environmental properties (i.e. EPS, TOM, mode grain size, mud and water content), suggesting that demographic processes may be responsible for periods of pronounced Ecosystem Engineering with densities of approx. 30 000 ind·m−2.
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A case study on the growth of Lanice conchilega (Pallas, 1766) aggregations and their Ecosystem Engineering impact on sedimentary processes
Journal of Experimental Marine Biology and Ecology, 2017Co-Authors: Renata Mamede Da Silva Alves, Jan Vanaverbeke, Jeanmarc Guarini, Magda Vincx, Carl Van Colen, Bart De Smet, Marijn Rabaut, Tjeerd J BoumaAbstract:Abstract Ecosystem engineers are organisms that modulate natural resources enabling the survival of other species. They drive environmental change and contribute to several coastal functional attributes such as landscape heterogeneity, sedimentary processes, and coastal protection. Our study focuses on the case of Lanice conchilega , a tube-building Ecosystem engineer whose aggregations impact sedimentary processes. This polychaete forms biogenic tube aggregations distributed on the coasts of the northern hemisphere from the shallow intertidal to depths of 1900 m. The aggregations engineer sedimentary processes autogenically by altering water flow at the benthic-boundary layer, and harbor highly diverse infaunal communities as a consequence. This study evaluates the relationships between intertidal L. conchilega aggregations and sedimentary processes at the intertidal zone of a sandy beach in northern France. Three experiments were executed to investigate (1) the effects of L. conchilega presence on sedimentary processes, as well as (2) the impacts of sedimentation on L. conchilega survival and patch growth, and (3) assess small-scale spatial heterogeneity in density and Ecosystem Engineering in L. conchilega aggregations. Weekly estimations of sedimentary properties in-situ showed that net deposition is significantly higher inside L. conchilega aggregations than in bare sand; whereas sediment mixing depth is noticeably reduced in comparison and regardless of patch tidal height. Variations in tube density above 3200 ind·m − 2 did not significantly impact sedimentary properties suggesting that the relationship between flow attenuation and tube density is nonlinear. In-situ monitoring of L. conchilega aggregations revealed different temporal trends for tube density and EPS content at the sediment surface between the center and edges of patches. This hints at the presence of environmental gradients within aggregations that may cause small-scale spatial heterogeneity. Finally, laboratory experiments showed significantly higher mortality rates and tube building activity in the presence of sediment deposition between 5 cm and 12 cm in column height. Results are in agreement with previous research suggesting that a positive feedback between sedimentation and tube-building activity drives the vertical expansion of patches. However, vertical expansion may be limited by deposition-induced mortality, thereby controlling population abundance.
Han Olff - One of the best experts on this subject based on the ideXlab platform.
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large scale Ecosystem Engineering by flamingos and fiddler crabs on west african intertidal flats promote joint food availability
Oikos, 2019Co-Authors: Elhacen Mohamed Elhacen, Tjeerd J Bouma, Puck Oomen, Theunis Piersma, Han OlffAbstract:Although the Ecosystem Engineering concept is well established in ecology, cases of joint Engineering by multiple species at large scales remain rare. Here, we combine observational studies and exclosure experiments to investigate how co-occurring greater flamingos Phoenicopterus roseus and fiddler crabs Uca tangeri promote their own and each other's food availability by creating a spatially complex mosaic of depressions (bowls, gullies) and hummocks (plateaus, mounds) in the intertidal zone. This results in a mosaic of microhabitats with different tidal inundation regimes. These microhabitats are spatially organized with labyrinth-like patterns in the high intertidal zone and spotted patterns in the lower intertidal, both of which likely arise from biophysical interactions between these organisms and hydrodynamic forces. We show that the resulting spatial complexity is vital for biofilm production. The depression microhabitats were wetter and richer in organic matter and biofilms compared with hummocks. Excluding flamingos and crabs resulted in an increase in biofilm biomass over the shorter term (six months), but a decrease over the longer term (after one year). Moreover, our results strongly suggest that these biogeomorphological microhabitats in the mosaics were maintained by the feeding activities of flamingos and to a lesser extent crabs. During a period of flamingo exclusion, all the spotted patterns filled up with sediment, while the exclusion of crabs led to gradual sediment accumulation in the labyrinth-like patterns. Collectively, these findings provide empirical evidence for large-scale joint promotion of food availability by multiple taxa in a marine Ecosystem.
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Ecosystem Engineering by seagrasses interacts with grazing to shape an intertidal landscape.
PloS one, 2012Co-Authors: Tjisse Van Der Heide, Han Olff, Johan S. Eklöf, Egbert H. Van Nes, Els M. Van Der Zee, Serena Donadi, Ellen J. Weerman, Britas Klemens ErikssonAbstract:Self-facilitation through Ecosystem Engineering (i.e., organism modification of the abiotic environment) and consumer-resource interactions are both major determinants of spatial patchiness in Ecosystems. However, interactive effects of these two mechanisms on spatial complexity have not been extensively studied. We investigated the mechanisms underlying a spatial mosaic of low-tide exposed hummocks and waterlogged hollows on an intertidal mudflat in the Wadden Sea dominated by the seagrass Zostera noltii. A combination of field measurements, an experiment and a spatially explicit model indicated that the mosaic resulted from localized sediment accretion by seagrass followed by selective waterfowl grazing. Hollows were bare in winter, but were rapidly colonized by seagrass during the growth season. Colonized hollows were heavily grazed by brent geese and widgeon in autumn, converting these patches to a bare state again and disrupting sediment accretion by seagrass. In contrast, hummocks were covered by seagrass throughout the year and were rarely grazed, most likely because the waterfowl were not able to employ their preferred but water requiring feeding strategy ('dabbling') here. Our study exemplifies that interactions between Ecosystem Engineering by a foundation species (seagrass) and consumption (waterfowl grazing) can increase spatial complexity at the landscape level.
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Major changes in the ecology of the Wadden Sea : Human impacts, Ecosystem Engineering and sediment dynamics
Ecosystems, 2010Co-Authors: Britas Klemens Eriksson, Theunis Piersma, Tjisse Van Der Heide, Johan Van De Koppel, Henk W. Van Der Veer, Han OlffAbstract:Shallow soft-sediment systems are mostly dominated by species that, by strongly affecting sediment dynamics, modify their local environment. Such Ecosystem Engineering species can have either sediment-stabilizing or sediment-destabilizing effects on tidal flats. They interplay with abiotic forcing conditions (wind, tide, nutrient inputs) in driving the community structure and generating spatial heterogeneity, determining the composition of different communities of associated species, and thereby affecting the channelling of energy through different compartments in the food web. This suggests that, depending on local species composition, tidal flats may have conspicuously different geomorphology and biological functions under similar external conditions. Here we use a historical reconstruction of benthic production in the Wadden Sea to construct a framework for the relationships between human impacts, Ecosystem Engineering and sediment dynamics. We propose that increased sediment disturbances by human exploitation interfere with biological controls of sediment dynamics, and thereby have shifted the dominant compartments of both primary and secondary production in the Wadden Sea, transforming the intertidal from an internally regulated and spatially heterogeneous, to an externally regulated and spatially homogenous system. This framework contributes to the general understanding of the interaction between biological and environmental control of Ecosystem functioning, and suggests a general framework for predicting effects of human impacts on soft-bottom Ecosystems
Clive G. Jones - One of the best experts on this subject based on the ideXlab platform.
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integrating Ecosystem Engineering and food webs
Oikos, 2014Co-Authors: Dirk Sanders, Tjeerd J Bouma, Clive G. Jones, Elisa Thébault, Tjisse Van Der Heide, Jim Van Belzen, Sébastien BarotAbstract:Ecosystem Engineering, the physical modification of the environment by organisms, is a common and often influential process whose significance to food web structure and dynamics is largely unknown. In the light of recent calls to expand food web studies to include non-trophic interactions, we explore how we might best integrate Ecosystem Engineering and food webs. We provide rationales justifying their integration and present a provisional framework identifying how Ecosystem Engineering can affect the nodes and links of food webs and overall organization; how trophic interactions with the engineer can affect the Engineering; and how feedbacks between Engineering and trophic interactions can affect food web structure and dynamics. We use a simple integrative food chain model to illustrate how feedbacks between the engineer and the food web can alter 1) Engineering effects on food web dynamics, and 2) food web responses to extrinsic environmental perturbations. We identify four general challenges to integration that we argue can readily be met, and call for studies that can achieve this integration and help pave the way to a more general understanding of interaction webs in nature.
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Integrating Ecosystem Engineering and food webs
Oikos, 2014Co-Authors: Dirk Sanders, Tjeerd J Bouma, Clive G. Jones, Elisa Thébault, Tjisse Van Der Heide, Jim Van Belzen, Sébastien BarotAbstract:Ecosystem Engineering, the physical modification of the environment by organisms, is a common and often influential process whose significance to food web structure and dynamics is largely unknown. In the light of recent calls to expand food web studies to include non-trophic interactions, we explore how we might best integrate Ecosystem Engineering and food webs. We provide rationales justifying their integration and present a provisional framework identifying how Ecosystem Engineering can affect the nodes and links of food webs and overall organization; how trophic interactions with the engineer can affect the Engineering; and how feedbacks between Engineering and trophic interactions can affect food web structure and dynamics. We use a simple integrative food chain model to illustrate how feedbacks between the engineer and the food web can alter 1) Engineering effects on food web dynamics, and 2) food web responses to extrinsic environmental perturbations. We identify four general challenges to integration that we argue can readily be met, and call for studies that can achieve this integration and help pave the way to a more general understanding of interaction webs in nature. Synthesis All species are affected by their physical environment. Because Ecosystem Engineering species modify the physical environment and belong to food webs, such species are potentially one of the most important bridges between the trophic and non-trophic. We examine how to integrate the so far, largely independent research areas of Ecosystem Engineering and food webs. We present a conceptual framework for understanding how Engineering can affect food webs and vice versa, and how feedbacks between the two alter Ecosystem dynamics. With appropriate empirical studies and models, integration is achievable, paving the way to a more general understanding of interaction webs in nature.
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Ecosystem Engineering, environmental decay and environmental states of landscapes
Oikos, 2012Co-Authors: Xavier Raynaud, Clive G. Jones, Sébastien BarotAbstract:Although environmental modification by Ecosystem engineers influences species distributions and abundances and ecological process rates, general determinants of the environmental states of engineered landscapes are not well understood. Here we develop a general, spatially implicit model of engineered landscapes that includes parameters driving engineer populations (demographics, environmental modification) and environmental decay. We show that average environmental states and heterogeneities of landscapes are the result of a balance between parameters determining Engineering rates and decay rates that can be expressed as a net Engineering ratio (NER). This ratio highlights the need to include environmental decay in Ecosystem Engineering studies. Moreover, it defines a significant engineer as one that can alter the environment despite decay and generates expectations for different kinds of effects on the engineer, other species and ecological processes depending on ratio values. Finally, it suggests that, in general, decay places limits as to what can be inferred about engineer population dynamics from environmental dynamics and vice versa.
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Ecosystem engineers and geomorphological signatures in landscapes
Geomorphology, 2011Co-Authors: Clive G. JonesAbstract:Abstract Biogeomorphologists study the roles of biota in landscape formation and decay. Ecologists interested in Ecosystem Engineering study environmental change caused by biota and the consequences for the engineer, other organisms, and ecological processes. The interface is geomorphological change, an interface both are aware of but study somewhat independently and differently. Interaction and integration among the two fields is the goal of this special issue. Here I take an ecological perspective of geomorphological change caused by Ecosystem engineers in patches within landscapes that I hope can help facilitate this goal. I ask the following general questions: When will an Ecosystem Engineering species create a geomorphological signature in a landscape? What, in qualitative terms, is such a signature? How can the signature be estimated and how long will it last? What engineer attributes and ecological factors will determine signature change? What creates complications? How do the answers inform whether or not life leaves a geomorphological signature? To attempt answers, I develop a provisional, general theory of Ecosystem Engineering signatures that draws on and integrates a geomorphological foundation of balance between formation and decay; landscape patch dynamics; a general framework for Ecosystem Engineering; and empirical studies. I treat a landscape Engineering signature as the balance of rates of formation (F) and rates of decay (D) across patches whose ratio value (F/D) can be transformed (> 1), intermediate (1) or untransformed (
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a framework for understanding physical Ecosystem Engineering by organisms
Oikos, 2010Co-Authors: Clive G. Jones, Jorge L Gutierrez, James E Byers, Jeffrey A Crooks, John G Lambrinos, Theresa Sinicrope TalleyAbstract:While well-recognized as an important kind of ecological interaction, physical Ecosystem Engineering by organisms is diverse with varied consequences, presenting challenges for developing and using general understanding. There is also still some uncertainty as to what it is, and some skepticism that the diversity of Engineering and its effects is amenable to conceptual integration and general understanding. What then, are the key cause/effect relationships and what underlies them? Here we develop, enrich and extend our extant understanding of physical Ecosystem Engineering into an integrated framework that exposes the essential cause/effect relationships, their underpinnings, and the interconnections that need to be understood to explain or predict Engineering effects. The framework has four cause/effect relationships linking four components: 1. An engineer causes structural change; 2. Structural change causes abiotic change; 3. Structural and abiotic change cause biotic change; 4. Structural, abiotic and biotic change can feedback to the engineer. The first two relationships describe an Ecosystem Engineering process and abiotic dynamics, while the second two describe biotic consequence for other species and the engineer. The four relationships can be parameterized and linked using time-indexed equations that describe engineered system dynamics. After describing the relationships we discuss the utility of the framework; how it might be enriched; and briefly how it can be used to identify intersections of Ecosystem Engineering with fields outside ecology.
Peter M. J. Herman - One of the best experts on this subject based on the ideXlab platform.
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Ecosystem Engineering creates a new path to resilience in plants with contrasting growth strategies.
Oecologia, 2019Co-Authors: Laura M. Soissons, Peter M. J. Herman, Marieke M. Van Katwijk, Qiuying Han, Tom Ysebaert, Tjeerd J BoumaAbstract:Plant species can be characterized by different growth strategies related to their inherent growth and recovery rates, which shape their responses to stress and disturbance. Ecosystem Engineering, however, offers an alternative way to cope with stress: modifying the environment may reduce stress levels. Using an experimental study on two seagrass species with contrasting traits, the slow-growing Zostera marina vs. the fast-growing Zostera japonica, we explored how growth strategies versus Ecosystem Engineering may affect their resistance to stress (i.e. addition of organic material) and recovery from disturbance (i.e. removal of above-ground biomass). Ecosystem Engineering was assessed by measuring sulphide levels in the sediment porewater, as seagrass plants can keep sulphide levels low by aerating the rhizosphere. Consistent with predictions, we observed that the fast-growing species had a high capacity to recover from disturbance. It was also more resistant to stress and still able to maintain high standing stock with increasing stress levels because of its Ecosystem Engineering capacity. The slow-growing species was not able to maintain its standing stock under stress, which we ascribe to a weak capacity for Ecosystem Engineering regarding this particular stress. Overall, our study suggests that the combination of low-cost investment in tissues with Ecosystem Engineering to alleviate stress creates a new path in the growth trade-off between investment in strong tissues or fast growth. It does so by being both fast in recovery and more resistant. As such low-cost Ecosystem Engineering may occur in more species, we argue that it should be considered in assessing plant resilience.
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Ecosystem Engineering Effects of Aster tripolium and Salicornia procumbens Salt Marsh on Macrofaunal Community Structure
Estuaries and Coasts, 2012Co-Authors: Peter M. J. HermanAbstract:This paper examines how perennial Aster tripolium and annual Salicornia procumbens salt marshes alter the biomass, density, taxon diversity, and community structure of benthic macrofauna, and also examines the role of elevation, sediment grain size, plant cover, and marsh age. Core samples were collected on a fixed grid on an intertidal flat in the Westerschelde estuary (51.4° N, 4.1° E) over 5 years (2004–2008) of salt marsh development. In unvegetated areas, macrobenthic biomass, density, and taxon diversity were highest when elevation was highest, benthic diatoms were most abundant, and sediment median grain size was smallest. In contrast, in salt marsh areas, macrobenthic biomass and taxon diversity increased with median grain size, while the effects of elevation and diatom abundance on macrobenthic biomass, density, and diversity were not significant. In fine sediments, macrofaunal community structure in the salt marsh was particularly affected; common polychaetes such as Nereis diversicolor , Heteromastus filiformis , and Pygospio elegans had low abundance and oligochaetes had high abundance. Marsh age had a negative influence on the density of macrofauna, and A. tripolium stands had lower macrofaunal densities than the younger S. procumbens stands. There were no significant effects of marsh age, plant cover, and vegetation type on macrobenthic biomass, taxon diversity, and community structure. The results highlight that Ecosystem Engineering effects of salt marsh plants on macrofauna are conditional. Organic enrichment of the sediment and mechanical hindering of macrofaunal activity by plant roots are proposed as plausible mechanisms for the influence of the salt marsh plants on macrofauna.
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Conditional outcome of Ecosystem Engineering: A case study on tussocks of the salt marsh pioneer Spartina anglica
Geomorphology, 2012Co-Authors: Thorsten Balke, Peter M. J. Herman, Paul C. Klaassen, Angus Garbutt, Daphne Van Der Wal, Tjeerd J BoumaAbstract:The salt marsh grass Spartina anglica is an important habitat-modifying Ecosystem Engineering agent that facilitates large-scale salt marsh formation by enhancing sediment accretion. It dominates many European tidal environments and is invasive in many other parts of the world. We question (1) to what extent the Ecosystem Engineering ability of patchy Spartina vegetation depends on large-scale abiotic processes, and (2) whether tussock shape provides an indicator for future lateral salt marsh development. Analysing the topography of 83 individual tussocks in contrasting environments revealed that there are 6 clearly distinguishable tussock shapes, and that the classical example of a sediment-accumulating dome-shaped tussock only occurs under a limited set of abiotic conditions. The outcome of habitat modification by S. anglica is shown to be conditional, depending on large-scale morphodynamics and sediment grain size. Resulting tussock shape provides a clear indication for the long-term development of the pioneer zone. Understanding of the conditional outcome of Ecosystem Engineering is highly relevant in this era of climate change and ongoing anthropogenic influences on coastal Ecosystems.\ud \u
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Effects of mud sedimentation on lugworm Ecosystem Engineering
Journal of Sea Research, 2011Co-Authors: F. Montserrat, Wouter Suykerbuyk, R. Al-busaidi, T.j. Bouma, D. Van Der Wal, Peter M. J. HermanAbstract:Benthic Ecosystem Engineering organisms attenuate hydrodynamic or biogeochemical stress to ameliorate living conditions. Bioturbating infauna, like the lugworm Arenicola marina, determine intertidal process dynamics by maintaining the sediment oxygenated and sandy. Maintaining the permeability of the surrounding sediment enables them to pump water through the interstitial spaces, greatly increasing the oxygen availability. In a field experiment, both lugworm presence and siltation regime were manipulated to investigate to what extent lugworms are able to cope with sedimentation of increasing mud percentage and how this would affect its Ecosystem Engineering. Fluorescent tracers were added to experimentally deposited mud to visualise bioturbation effects on fine sediment fractions. Lugworm densities were not affected by an increasing mud percentage in experimentally deposited sediment. Negative effects are expected to occur under deposition with significantly higher mud percentages. Surface chlorophyll a content was a function of experimental mud percentage, with no effect of lugworm bioturbation. Surface roughness and sediment permeability clearly increased by lugworm presence, whereas sediment erosion threshold was not significantly affected by lugworms. The general idea that A. marina removes fine sediment fractions from the bed could not be confirmed. Rather, the main Ecosystem Engineering effect of A. marina is hydraulic destabilisation of the sediment matrix
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Comparing Ecosystem Engineering efficiency of two plant species with contrasting growth strategies
Ecology, 2010Co-Authors: Tjeerd J Bouma, M. De Vries, Peter M. J. HermanAbstract:Many Ecosystems are greatly affected by Ecosystem Engineering, such as coastal salt marshes, where macrophytes trap sediment by reducing hydrodynamic energy. Nevertheless, little is known about the costs and benefits that are imposed on Engineering species by the traits that underlie their Ecosystem Engineering capacity. We addressed this topic by comparing Ecosystem Engineering efficiency defined as the benefit-cost ratio per unit of biomass investment for two species from the intertidal habitat: the stiff grass Spartina anglica and the flexible grass Puccinellia maritima. These species were selected for their ability to modify their habitat by trapping large quantities of sediment despite their contrasting growth form. On a biomass basis, dissipation of hydrodynamic energy from waves (a proxy for benefits associated with Ecosystem Engineering capability as it relates to the sediment trapping capability) was strikingly similar for both salt marsh species, indicating that both species are equally effective in modifying their habitat. The drag forces per unit biomass (a proxy for costs associated with Ecosystem Engineering ability as it relates to the requirements on tissue construction and shoot anchoring to prevent breaking and/or washing away) were slightly higher in the species with flexible shoots. As a result, stiff Spartina vegetation had slightly higher Ecosystem Engineering efficiency, due to lower Engineering costs rather than to a higher Engineering effect. Thus, Spartina is a slightly more efficient rather than a more effective Ecosystem engineer. Ecosystem Engineering efficiency was found to be a species-specific characteristic, independent of vegetation density and relatively constant in space. Analyzing Ecosystem Engineering by quantifying trade-offs offers a useful way toward developing a better understanding of different Engineering strategies.
Theunis Piersma - One of the best experts on this subject based on the ideXlab platform.
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large scale Ecosystem Engineering by flamingos and fiddler crabs on west african intertidal flats promote joint food availability
Oikos, 2019Co-Authors: Elhacen Mohamed Elhacen, Tjeerd J Bouma, Puck Oomen, Theunis Piersma, Han OlffAbstract:Although the Ecosystem Engineering concept is well established in ecology, cases of joint Engineering by multiple species at large scales remain rare. Here, we combine observational studies and exclosure experiments to investigate how co-occurring greater flamingos Phoenicopterus roseus and fiddler crabs Uca tangeri promote their own and each other's food availability by creating a spatially complex mosaic of depressions (bowls, gullies) and hummocks (plateaus, mounds) in the intertidal zone. This results in a mosaic of microhabitats with different tidal inundation regimes. These microhabitats are spatially organized with labyrinth-like patterns in the high intertidal zone and spotted patterns in the lower intertidal, both of which likely arise from biophysical interactions between these organisms and hydrodynamic forces. We show that the resulting spatial complexity is vital for biofilm production. The depression microhabitats were wetter and richer in organic matter and biofilms compared with hummocks. Excluding flamingos and crabs resulted in an increase in biofilm biomass over the shorter term (six months), but a decrease over the longer term (after one year). Moreover, our results strongly suggest that these biogeomorphological microhabitats in the mosaics were maintained by the feeding activities of flamingos and to a lesser extent crabs. During a period of flamingo exclusion, all the spotted patterns filled up with sediment, while the exclusion of crabs led to gradual sediment accumulation in the labyrinth-like patterns. Collectively, these findings provide empirical evidence for large-scale joint promotion of food availability by multiple taxa in a marine Ecosystem.
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Major changes in the ecology of the Wadden Sea : Human impacts, Ecosystem Engineering and sediment dynamics
Ecosystems, 2010Co-Authors: Britas Klemens Eriksson, Theunis Piersma, Tjisse Van Der Heide, Johan Van De Koppel, Henk W. Van Der Veer, Han OlffAbstract:Shallow soft-sediment systems are mostly dominated by species that, by strongly affecting sediment dynamics, modify their local environment. Such Ecosystem Engineering species can have either sediment-stabilizing or sediment-destabilizing effects on tidal flats. They interplay with abiotic forcing conditions (wind, tide, nutrient inputs) in driving the community structure and generating spatial heterogeneity, determining the composition of different communities of associated species, and thereby affecting the channelling of energy through different compartments in the food web. This suggests that, depending on local species composition, tidal flats may have conspicuously different geomorphology and biological functions under similar external conditions. Here we use a historical reconstruction of benthic production in the Wadden Sea to construct a framework for the relationships between human impacts, Ecosystem Engineering and sediment dynamics. We propose that increased sediment disturbances by human exploitation interfere with biological controls of sediment dynamics, and thereby have shifted the dominant compartments of both primary and secondary production in the Wadden Sea, transforming the intertidal from an internally regulated and spatially heterogeneous, to an externally regulated and spatially homogenous system. This framework contributes to the general understanding of the interaction between biological and environmental control of Ecosystem functioning, and suggests a general framework for predicting effects of human impacts on soft-bottom Ecosystems
