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Dhib A, Ben Brahim M, Turki S, Aleya L. Contrasting key roles of Ruppia cirrhosa in a southern Mediterranean lagoon: reservoir for both biodiversity and harmful species and indicator of lagoon health status. MARINE POLLUTION BULLETIN 2013; 76:116-127. [PMID: 24079921 DOI: 10.1016/j.marpolbul.2013.09.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 09/02/2013] [Accepted: 09/08/2013] [Indexed: 06/02/2023]
Abstract
The distribution of Ruppia cirrhosa meadow density and its epiphytic organisms in relation with environmental factors were studied in summer 2011 at five stations in the Ghar El Melh lagoon (GML; southern Mediterranean Sea). Eleven epiphytic groups were recognised among which diatoms and dinoflagellates were the dominant groups and greatest contributors to temporal dissimilarity. An overwhelming concentrations of harmful microalgae was recorded, mainly represented by the toxic dinoflagellate Prorocentrum lima with maximal concentrations attaining 6 × 10(5)cells 100g(-1) of Ruppia fresh weight. The epifauna community accounted for only 1.4% of total epiphyte abundance and was comprised predominantly of nematodes (47.51%), ciliates (32.59%), fish eggs (7.2%) and larvae (4.95%). PERMANOVA analyses revealed a significant spatio-temporal variation of all epiphytic groups (p<0.01). In this study, R. cirrhosa and its epiphytes were studied as potential early warning indicators of the health status of GML waters.
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Affiliation(s)
- Amel Dhib
- Université de Franche-Comté, Laboratoire de Chrono-Environnement, UMR CNRS 6249, France; Institut National des Sciences et Technologies de la Mer (INSTM), Laboratoire Milieu Marin, Centre la Goulette, Tunisia
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Klose K, Cooper SD. Complex impacts of an invasive omnivore and native consumers on stream communities in California and Hawaii. Oecologia 2012; 171:945-60. [DOI: 10.1007/s00442-012-2449-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 08/23/2012] [Indexed: 12/01/2022]
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Law RJ. A Review of the Function and uses of, and Factors Affecting, Stream Phytobenthos. ACTA ACUST UNITED AC 2011. [DOI: 10.1608/frj-4.1.448] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Fröberg L, Stoll P, Baur A, Baur B. Snail herbivory decreases cyanobacterial abundance and lichen diversity along cracks of limestone pavements. Ecosphere 2011. [DOI: 10.1890/es10-00197.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Effenberger M, Diehl S, Gerth M, Matthaei CD. Patchy bed disturbance and fish predation independently influence the distribution of stream invertebrates and algae. J Anim Ecol 2011; 80:603-14. [PMID: 21323920 DOI: 10.1111/j.1365-2656.2011.01807.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Michael Effenberger
- Department Biology II, Aquatic Ecology, University of Munich (LMU), Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany
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Evaluating Relationships between Spatial Heterogeneity and the Biotic and Abiotic Environments. AMERICAN MIDLAND NATURALIST 2010. [DOI: 10.1674/0003-0031-163.2.351] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Limb RF, Fuhlendorf SD, Townsend DE. Heterogeneity of thermal extremes: driven by disturbance or inherent in the landscape. ENVIRONMENTAL MANAGEMENT 2009; 43:100-106. [PMID: 18491182 DOI: 10.1007/s00267-008-9147-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2007] [Revised: 04/14/2008] [Accepted: 04/27/2008] [Indexed: 05/26/2023]
Abstract
Ecologists are beginning to recognize the effect of heterogeneity on structure and function in arid and semiarid ecosystems. Additionally, the influences of temperature on ecosystems are widely documented, but landscape temperature patterns and relationships with vegetation are rarely reported in ecological studies. To better understand the importance of temperature patterns to the conservation and restoration of native ecosystems, we designed an experiment to investigate relationships among soil surface temperature, landscape heterogeneity, and grazing intensity. Grazing intensity did influence the vegetation structure and composition. Heavy treatments had the greatest bare ground and the least vertical structure. Ungrazed treatments had the most litter and live grass cover. However, average temperatures among the three grazing treatments were not different and ranged less than 2 degrees C during midday summer periods. The temperature difference between riparian and upland landscapes within grazing treatments was 21 degrees C. Landscape position (riparian vs. upland) did have a significant influence on soil surface temperature and produced a variation in temperature 11 times greater than grazing intensities. Thermal heterogeneity did not differ among grazing treatments. Lower soil surface temperatures (associated with riparian areas) may provide a critical thermal refuge for many animals in arid and semiarid ecosystems on hot summer days, when air temperatures can exceed 37 degrees C. Riparian zones, specifically riparian vegetation, are an important component in ecosystem management.
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Affiliation(s)
- Ryan F Limb
- Department of Natural Resource Ecology and Management, Oklahoma State University, 008c Agricultural Hall, Stillwater, OK 74078, USA.
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Bertrand KN, Gido KB. Effects of the herbivorous minnow, southern redbelly dace (Phoxinus erythrogaster), on stream productivity and ecosystem structure. Oecologia 2006; 151:69-81. [PMID: 17031700 DOI: 10.1007/s00442-006-0569-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2006] [Accepted: 09/11/2006] [Indexed: 10/24/2022]
Abstract
We used field and mesocosm experiments to measure effects of southern redbelly dace (Phoxinus erythrogaster), a grazing minnow, on stream ecosystem structure and function. Ecosystem structure was quantified as algal filament length, algal biomass, size distribution of particulate organic matter (POM), algal assemblage structure, and invertebrate assemblage structure, whereas ecosystem function was based on gross and net primary productivity. Our experiments showed that moderate densities of Phoxinus temporarily reduced mean algal filament length and mean size of POM relative to fishless controls. However, there was no detectable effect on algal biomass or ecosystem primary productivity. Several factors could explain the lack of effect of Phoxinus on primary productivity including increased algal production efficiency in grazed treatments or increased grazing by other organisms in fishless treatments. The inability of Phoxinus to reduce algal biomass and system productivity contrasts with experimental results based on other grazing minnows, such as the central stoneroller (Campostoma anomalum), and questions the generality of grazer effects in stream ecosystems. However, environmental venue and the spatial and temporal scale of ecosystem measurements can greatly influence the outcome of these experiments.
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Affiliation(s)
- Katie N Bertrand
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
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Werner EE, Peacor SD. LETHAL AND NONLETHAL PREDATOR EFFECTS ON AN HERBIVORE GUILD MEDIATED BY SYSTEM PRODUCTIVITY. Ecology 2006; 87:347-61. [PMID: 16637361 DOI: 10.1890/05-0091] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Indirect effects propagated through intervening species in a food web have important effects on community properties. Traditionally, these indirect effects have been conceptualized as mediated through density changes of the intervening species, but it is becoming increasingly apparent that those mediated through trait (phenotypic) responses also can be very important. Because density- and trait-mediated indirect effects have different properties, it is critical that we understand the mechanisms of transmission in order to predict how they will interact, and when or where they will be important. In this study, we examined the mechanisms and consequences of the lethal (density-mediated) and nonlethal (trait-mediated) effects of a larval odonate predator on a guild of four herbivore species (a larval anuran and three species of snails) and their resources. We also manipulated system productivity in order to explore the effects of environmental context on the transmission of these two types of indirect effects. We show that trait-mediated effects arising from the predator can be very strong relative to density-mediated effects on both the competing herbivores and the species composition and production of their resources. A number of these indirect effects are shown to be contingent on productivity of the system. We further present evidence that trait- and density-mediated indirect effects originating from a predator may be transmitted independently through different routes in a food web, particularly when spatial responses of the transmitting prey are involved. Finally, effects on prey growth due to trait responses to the predator varied from negative to positive in predictable ways as a function of time and indirect effects on the larger food web. These results indicate the important role that trait-mediated indirect effects can play in trophic cascades and keystone predator interactions, and we discuss how the mechanisms involved can be incorporated in theory.
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Affiliation(s)
- Earl E Werner
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor 48109, USA.
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K. Roll S, Diehl S, D. Cooper S. Effects of grazer immigration and nutrient enrichment on an open algae-grazer system. OIKOS 2005. [DOI: 10.1111/j.0030-1299.2005.12950.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Alvarez M, Peckarsky BL. How do grazers affect periphyton heterogeneity in streams? Oecologia 2004; 142:576-87. [PMID: 15688216 DOI: 10.1007/s00442-004-1759-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2004] [Accepted: 10/12/2004] [Indexed: 10/26/2022]
Abstract
The effects of grazing by stream invertebrates on algal biomass and spatial heterogeneity were tested experimentally in flow-through microcosms with natural substrates (rocks). One experiment tested the effects of fixed densities of three species of grazers (the caddisfly Allomyia sp. and two mayflies, Epeorus deceptivus and Baetis bicaudatus) on periphyton. Baetis was tested with and without chemical cues from fish predators, which reduced grazer foraging activity to levels similar to the less mobile mayfly (Epeorus). Mean algal biomass (chlorophyll a; chl a) was reduced in grazer treatments compared to ungrazed controls, but there were no differences among grazer treatments. Algal heterogeneity (Morisita index) increased with grazer mobility, with the highest heterogeneity occurring in the Baetis-no fish treatment (most mobile grazer) and the lowest in the caddisfly treatment (most sedentary grazer). A second experiment used a three factorial design, and tested whether initial resource distribution (homogeneous vs. heterogeneous), Baetis density (high vs. low) and fish odor (present vs. absent) affected grazer impact on algal resources. Abundances of Baetis and chl a on individual rocks were recorded to explore the mechanisms responsible for the observed distributions of algae. Initial resource heterogeneity was maintained despite being subjected to grazing. Mean chl a was highest in controls, as in experiment I, and effects of Baetis on algal biomass increased with grazer density. There were no fish effects on algal biomass and no effects of grazer density or fish on algal heterogeneity. At the scale of individual rocks Baetis was unselective when food was homogeneously distributed, but chose high-food rocks when it was heterogeneously distributed. Results of these mechanistic experiments showed that Baetis can track resources at the scale of single rocks; and at moderate densities mobile grazers could potentially maintain periphyton distributions observed in natural streams.
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Affiliation(s)
- Maruxa Alvarez
- Rocky Mountain Biological Laboratory, 529, Crested Butte, CO 81224, USA
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Flecker AS, Taylor BW. TROPICAL FISHES AS BIOLOGICAL BULLDOZERS: DENSITY EFFECTS ON RESOURCE HETEROGENEITY AND SPECIES DIVERSITY. Ecology 2004. [DOI: 10.1890/03-0194] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Olden JD, Hoffman AL, Monroe JB, Poff NL. Movement behaviour and dynamics of an aquatic insect in a stream benthic landscape. CAN J ZOOL 2004. [DOI: 10.1139/z04-094] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Understanding not just where organisms move but how they move is an important step towards integrating animal behaviour into landscape ecology. The three-dimensional landscape of a streambed provides an ideal setting for forging this integration because of the persuasive effects of flowing water. In this study, we experimentally examine the larval movement of the case-building caddisfly Agapetus boulderensis Milne, 1936 in response to two current velocities in each of five levels of contrasting habitat types (i.e., smooth patches that facilitate movement and thick algal patches that constrain movement). Detailed behavioural observations showed that larvae employed two distinctly different strategies of movement in different current velocities: faster crawling and slower pivoting. Our results suggest that individual decision-making between crawling and pivoting is related to the magnitude of current velocity across the streambed, and the frequency at which larvae employ these behaviours translates into differential movement rates and directions. Strong concordance between a conceptual model and our results supports the notion that the presence of structural "nonhabitat" patches at high current velocities may create areas of local flow interruption and refugia. This, in turn, plays an important role in eliciting either crawling or pivoting and in shaping patterns and directions of larval movement, and by extension resource acquisition.
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Robson BJ, Chester ET. Spatial patterns of invertebrate species richness in a river: the relationship between riffles and microhabitats. AUSTRAL ECOL 1999. [DOI: 10.1046/j.1442-9993.1999.01007.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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COOPER SCOTTD, DIEHL SEBASTIAN, KRATZ KIM, SARNELLE ORLANDO. Implications of scale for patterns and processes in stream ecology. AUSTRAL ECOL 1998. [DOI: 10.1111/j.1442-9993.1998.tb00703.x] [Citation(s) in RCA: 134] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Lodge DM, Cronin G, van Donk E, Froelich AJ. Impact of Herbivory on Plant Standing Crop: Comparisons Among Biomes, Between Vascular and Nonvascular Plants, and Among Freshwater Herbivore Taxa. THE STRUCTURING ROLE OF SUBMERGED MACROPHYTES IN LAKES 1998. [DOI: 10.1007/978-1-4612-0695-8_8] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Habitat architecture and trophic interaction strength in a river: riffle-scale effects. Oecologia 1996; 107:411-420. [DOI: 10.1007/bf00328458] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/1995] [Accepted: 02/19/1996] [Indexed: 11/24/2022]
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Branch LC, Villarreal D, Hierro JL, Portier KM. Effects of local extinction of the plains vizcacha (Lagostomus maximus) on vegetation patterns in semi-arid scrub. Oecologia 1996; 106:389-399. [DOI: 10.1007/bf00334567] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/1995] [Accepted: 11/14/1995] [Indexed: 11/30/2022]
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Scales of spatial patterns of distribution of intertidal invertebrates. Oecologia 1996; 107:212-224. [PMID: 28307307 DOI: 10.1007/bf00327905] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/1995] [Accepted: 02/01/1996] [Indexed: 10/26/2022]
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