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Decomposition of vegetal detritus is one of the most fundamental ecosystem processes. In complex landscapes, the fate of litter of terrestrial plants may depend on whether it ends up decomposing in terrestrial or aquatic conditions. However, (1) to what extent decomposition rates are controlled by environmental conditions or by detritus type, and (2) how important the composition of the detritivorous fauna is in mediating decomposition in different habitats, remain as unanswered questions. We incubated two contrasting detritus types in three distinct habitat types in Coastal Georgia, USA, to test the hypotheses that (1) the litter fauna composition depends on the habitat and the litter type available, and (2) litter mass loss (as a proxy for decomposition) depends on environmental conditions (habitat) and the litter type. We found that the abundance of most taxa of the litter fauna depends primarily on habitat. Litter type became a stronger driver for some taxa over time, but the overall faunal composition was only weakly affected by litter type. Decomposition also depends strongly on habitat, with up to ca. 80% of the initial detrital mass lost over 25 months in the marsh and forest habitats, but less than 50% lost in the creek bank habitat. Mass loss rates of oak versus pine litter differed initially but converged within habitat types within 12 months. We conclude that, although the habitat type is the principle driver of the community composition of the litter fauna, litter type is a significant driver of litter mass loss in the early stages of the decomposition process. With time, however, litter types become more and more similar, and habitat becomes the dominating factor in determining decomposition of older litter. Thus, the major driver of litter mass loss changes over time from being the litter type in the early stages to the habitat (environmental conditions) in later stages.
Franziska K. Seer; Gregor Putze; Steven C. Pennings; Martin Zimmer. Drivers of litter mass loss and faunal composition of detritus patches change over time. Ecology and Evolution 2021, 11, 9642 -9651.
AMA StyleFranziska K. Seer, Gregor Putze, Steven C. Pennings, Martin Zimmer. Drivers of litter mass loss and faunal composition of detritus patches change over time. Ecology and Evolution. 2021; 11 (14):9642-9651.
Chicago/Turabian StyleFranziska K. Seer; Gregor Putze; Steven C. Pennings; Martin Zimmer. 2021. "Drivers of litter mass loss and faunal composition of detritus patches change over time." Ecology and Evolution 11, no. 14: 9642-9651.
Many mangrove crab species drag freshly fallen leaf litter into their burrows and store it there for some time prior to consumption. Potential explanations for this behavior include (a) avoidance of competition for a scarce resource, (b) prevention of removal of a scarce resource upon tidal outwelling, or (c) processing of an initially unpalatable food source, be it physically through leaching, through the activity of the sediment microbiota, or driven by the activity of the crab itself. To test the latter, we study the effect of burying mangrove leaf litter on two relevant physicochemical litter characteristics and on its digestibility to crabs in a laboratory experiment, using artificial substratum with low microbial activity. Freshly fallen leaves of two common mangrove species, Bruguiera gymnorhiza and Ceriops tagal, were left for two weeks either inside burrows used by Neosamartium asiaticum (Sesarmidae), or on top of the substratum, before they were offered to the crabs as food. Leaf toughness and total phenolic content differed significantly between mangrove species. Upon two weeks of decay, phenolic content of both leaf litter species and toughness of B. gymnorhiza changed significantly. However, neither litter characteristcs nor assimilation efficiency differed between treatments. We conclude that storing mangrove leaf litter in crab burrows in a microbe-poor environment does not affect litter digestibility. Hence, crabs themselves do not contribute to litter processing during storage inside the burrow. If it is litter processing, rather than the avoidance of competition or litter removal by tides, that renders the storage of litter inside the burrow advantageous, it will be microbial activity that drives this process. Further studies should explicitly focus on processing through the activity of the sediment microbiota.
Sophie J. Forgeron; Aline F. Quadros; Martin Zimmer. Crab‐driven processing does not explain leaf litter‐deposition in mangrove crab burrows. Ecology and Evolution 2021, 11, 8856 -8862.
AMA StyleSophie J. Forgeron, Aline F. Quadros, Martin Zimmer. Crab‐driven processing does not explain leaf litter‐deposition in mangrove crab burrows. Ecology and Evolution. 2021; 11 (13):8856-8862.
Chicago/Turabian StyleSophie J. Forgeron; Aline F. Quadros; Martin Zimmer. 2021. "Crab‐driven processing does not explain leaf litter‐deposition in mangrove crab burrows." Ecology and Evolution 11, no. 13: 8856-8862.
Mangrove forests provide a large variety of ecosystem services (ES) to coastal societies. Using a case study focusing on the Ajuruteua peninsula in Northern Brazil and two ES, food provisioning (ES1) and global climate regulation (ES2), this paper proposes a new framework for quantifying and valuing mangrove ES and allow for their small-scale mapping. We modelled and spatialised the two ES from different perspectives, the demand (ES1) and the supply (ES2) side respectively. This was performed by combining worldwide databases related to the global human population (ES1) or mangrove distribution and canopy height (ES2) with locally derived parameters, such as crab catches (ES1) or species-specific allometric equations based on local estimates of tree structural parameters (ES2). Based on this approach, we could estimate that the area delivers the basic nutrition of about 1400 households, which equals 2.7 million USD, and that the mangrove biomass in the area contains 2.1 million Mg C, amounting to 50.9 million USD, if it were paid as certificates. In addition to those figures, we provide high-resolution maps showing which areas are more valuable for the two respective ES, information that could help inform management strategies in the future.
Robin Gutting; Ralf-Uwe Syrbe; Karsten Grunewald; Ulf Mehlig; Véronique Helfer; Martin Zimmer. The Benefits of Combining Global and Local Data—A Showcase for Valuation and Mapping of Mangrove Climate Regulation and Food Provisioning Services within a Protected Area in Pará, North Brazil. Land 2021, 10, 432 .
AMA StyleRobin Gutting, Ralf-Uwe Syrbe, Karsten Grunewald, Ulf Mehlig, Véronique Helfer, Martin Zimmer. The Benefits of Combining Global and Local Data—A Showcase for Valuation and Mapping of Mangrove Climate Regulation and Food Provisioning Services within a Protected Area in Pará, North Brazil. Land. 2021; 10 (4):432.
Chicago/Turabian StyleRobin Gutting; Ralf-Uwe Syrbe; Karsten Grunewald; Ulf Mehlig; Véronique Helfer; Martin Zimmer. 2021. "The Benefits of Combining Global and Local Data—A Showcase for Valuation and Mapping of Mangrove Climate Regulation and Food Provisioning Services within a Protected Area in Pará, North Brazil." Land 10, no. 4: 432.
Novia Arinda Pradisty; A. Aldrie Amir; Martin Zimmer. Correction to: Plant species- and stage-specific differences in microbial decay of mangrove leaf litter: the older the better? Oecologia 2021, 195, 859 -859.
AMA StyleNovia Arinda Pradisty, A. Aldrie Amir, Martin Zimmer. Correction to: Plant species- and stage-specific differences in microbial decay of mangrove leaf litter: the older the better? Oecologia. 2021; 195 (4):859-859.
Chicago/Turabian StyleNovia Arinda Pradisty; A. Aldrie Amir; Martin Zimmer. 2021. "Correction to: Plant species- and stage-specific differences in microbial decay of mangrove leaf litter: the older the better?" Oecologia 195, no. 4: 859-859.
Leaf litter and its breakdown products represent an important input of organic matter and nutrients to mangrove sediments and adjacent coastal ecosystems. It is commonly assumed that old-grown stands with mature trees contribute more to the permanent sediment organic matter pool than younger stands. However, neither are interspecific differences in leaf decay rates taken into account in this assumption nor is our understanding of the underlying mechanisms or drivers of differences in leaf chemistry sufficient. This study examines the influence of different plant species and ontogenetic stage on the microbial decay of mangrove leaf litter. A litterbag experiment was conducted in the Matang Mangrove Forest Reserve, Malaysia, to monitor leaf litter mass loss, and changes in leaf litter chemistry and microbial enzyme activity. Four mangrove species of different morphologies were selected, namely the trees Rhizophora apiculata and Bruguiera parviflora, the fern Acrostichum aureum and the shrub Acanthus ilicifolius. Decay rates of mangrove leaf litter decreased from A. ilicifolius to R. apiculata to B. parviflora to A. aureum. Leaf litter mass, total phenolic content, protein precipitation capacity and phenol oxidase activity were found to decline rapidly during the early stage of decay. Leaf litter from immature plants differed from that of mature plants in total phenolic content, phenolic signature, protein precipitating capacity and protease activity. For R. apiculata, but not of the other species, leaf litter from immature plants decayed faster than the litter of mature plants. The findings of this study advance our understanding of the organic matter dynamics in mangrove stands of different compositions and ages and will, thus, prove useful in mangrove forest management.
Novia Arinda Pradisty; A. Aldrie Amir; Martin Zimmer. Plant species- and stage-specific differences in microbial decay of mangrove leaf litter: the older the better? Oecologia 2021, 195, 843 -858.
AMA StyleNovia Arinda Pradisty, A. Aldrie Amir, Martin Zimmer. Plant species- and stage-specific differences in microbial decay of mangrove leaf litter: the older the better? Oecologia. 2021; 195 (4):843-858.
Chicago/Turabian StyleNovia Arinda Pradisty; A. Aldrie Amir; Martin Zimmer. 2021. "Plant species- and stage-specific differences in microbial decay of mangrove leaf litter: the older the better?" Oecologia 195, no. 4: 843-858.
Lignins are major structural components of plant cell walls and hence of plant litter. The complex polymer effectively resists chemical and enzymatic attack, even more than other important phenolic litter constituents such as condensed tannins. The enzymatic degradation of both lignin and condensed tannins depends on the oxidation of aromatic rings. Since some of the enzymes catalyzing these reactions exhibit a degree of substrate specificity, the oxidation of different phenolic compounds involves different classes of phenol oxidases. This chapter describes a method for quantifying the activity of phenol-oxidizing enzymes based on the determination of increases in oxidation products. The approach potentially covers the combined activities of several enzymes with different substrate affinities. Specifically, a buffered extract from plant litter, animal gut content, or another type of environmental sample is added to a solution of a suitable phenolic substrate. Its oxidation is followed over time as an increase in brown coloration determined spectrophotometrically at 520 nm, while suppressing polymerization of the quinonic oxidation products. Since those oxidation products are not precisely defined, the described method yields information only on the relative phenol oxidation capacity. Therefore, meaningful comparisons are restricted to data obtained from identical substrates.
Martin Zimmer. Phenol Oxidation. Methods to Study Litter Decomposition 2020, 433 -437.
AMA StyleMartin Zimmer. Phenol Oxidation. Methods to Study Litter Decomposition. 2020; ():433-437.
Chicago/Turabian StyleMartin Zimmer. 2020. "Phenol Oxidation." Methods to Study Litter Decomposition , no. : 433-437.
Mangrove forests are among the world’s most productive ecosystems and provide essential ecosystem services such as global climate regulation through the sequestration of carbon. A detailed understanding of the influence of drivers of ecosystem connectivity (in terms of exchange of suspended particulate organic matter), such as geomorphic setting and carbon stocks, among coastal ecosystems is important for being able to depict carbon dynamics. Here, we compared carbon stocks, CO2 fluxes at the sediment-air interface, concentrations of dissolved organic carbon and suspended particulate organic carbon across a mangrove-seagrass-tidal flat seascape. Using stable isotope signatures of carbon and nitrogen in combination with MixSIAR models, we evaluated the contribution of organic matter from different sources among the different seascape components. Generally, carbon concentration was higher as dissolved organic carbon than as suspended particulate matter. Geomorphic settings of the different locations reflected the contributions to particulate organic matter of the primary producers. For example, the biggest contributors in the riverine location were mangrove trees and terrestrial plants, while in fringing locations oceanic and macroalgal sources dominated. Anthropogenic induced changes at the coastal level (i.e. reduction of mangrove forests area) may affect carbon accumulation dynamics in adjacent coastal ecosystems.
Daniel A. Saavedra-Hortua; Daniel A. Friess; Martin Zimmer; Lucy Gwen Gillis. Sources of Particulate Organic Matter across Mangrove Forests and Adjacent Ecosystems in Different Geomorphic Settings. Wetlands 2020, 40, 1047 -1059.
AMA StyleDaniel A. Saavedra-Hortua, Daniel A. Friess, Martin Zimmer, Lucy Gwen Gillis. Sources of Particulate Organic Matter across Mangrove Forests and Adjacent Ecosystems in Different Geomorphic Settings. Wetlands. 2020; 40 (5):1047-1059.
Chicago/Turabian StyleDaniel A. Saavedra-Hortua; Daniel A. Friess; Martin Zimmer; Lucy Gwen Gillis. 2020. "Sources of Particulate Organic Matter across Mangrove Forests and Adjacent Ecosystems in Different Geomorphic Settings." Wetlands 40, no. 5: 1047-1059.
Decomposition processes influence the formation of soil organic carbon stocks, and it is necessary to understand how both will respond to climate change. A Space-For-Time (SFT) substitution allows the comparison of litter decomposition under current and future conditions in the field, using a spatial gradient of environmental conditions. Here we used a SFT approach to study the effects of a difference in temperature similar to the predicted increase of 3.2–3.5 °C in Central Europe until 2100. To simulate this difference, we setup a five-fold replicated SFT substitution along mountain slopes and compared decomposition in two sites differing in ∿3.6 °C (600 vs 1200 m a.s.l). With this setup we compared the decomposition of high-quality (nettle) and low-quality (hay) litter, with and without fauna access, during summer, in five mountains in the Austrian Alps (Salzburg). Temperature loggers placed in one of the mountains indicated that the actual difference between the two altitudes was only ∿1.8 °C during summer. Nonetheless, decomposition of low-quality litter was 12% faster at 600 m than at 1200 m; altitude alone explained 19% of total variance. On the contrary, decomposition of high-quality litter was 9% faster at 1200 m. Fauna was the main driver of the high-quality litter decomposition at both altitudes and explained 26% of total variance, whereas altitude explained only 10%. Decomposition rates of the high-quality litter (21.4 ± 2.9 mg g−1 d−1; ±s.d.) was much higher than that of the low-quality (7.9 ± 1.0 mg g−1 d−1). Overall, the decomposition of the low-quality, slow-decomposing litter was more sensitive to warming and less influenced by the activity of detritivores, compared to a litter of higher quality. Through the use of the SFT substitution, we detected that a large part of the variance explained by the models was due to the variability between blocks and mountains, highlighting the important effect of spatial heterogeneity and the need for more replicated, field-based studies, to estimate the responses of decomposition processes to climate change.
Jenny Faber; Aline F. Quadros; Martin Zimmer. A Space-For-Time approach to study the effects of increasing temperature on leaf litter decomposition under natural conditions. Soil Biology and Biochemistry 2018, 123, 250 -256.
AMA StyleJenny Faber, Aline F. Quadros, Martin Zimmer. A Space-For-Time approach to study the effects of increasing temperature on leaf litter decomposition under natural conditions. Soil Biology and Biochemistry. 2018; 123 ():250-256.
Chicago/Turabian StyleJenny Faber; Aline F. Quadros; Martin Zimmer. 2018. "A Space-For-Time approach to study the effects of increasing temperature on leaf litter decomposition under natural conditions." Soil Biology and Biochemistry 123, no. : 250-256.
Population declines in shark species have been reported on local and global scales, with overfishing, habitat destruction and climate change posing severe threats. The lack of species‐specific baseline data on ecology and distribution of many sharks, however, makes conservation measures challenging. Here, we present a fisheries‐independent shark survey from the Fiji Islands, where scientific knowledge on locally occurring elasmobranchs is largely still lacking despite the location's role as a shark hotspot in the Pacific. Juvenile shark abundance in the fishing grounds of the Ba Estuary (north‐western Viti Levu) was assessed with a gillnet‐ and longline‐based survey from December 2015 to April 2016. A total of 103 juvenile sharks identified as blacktip Carcharhinus limbatus (n = 57), scalloped hammerhead Sphyrna lewini (n = 35), and great hammerhead Sphyrna mokarran (n = 11) sharks were captured, tagged, and released. The condition of umbilical scars (68% open or semihealed), mean sizes of individuals (±SD) (C. limbatus: 66.5 ± 3.8 cm, S. lewini: 51.8 ± 4.8 cm, S. mokarran 77.4 ± 2.8 cm), and the presence of these species over recent years (based on fishermen interviews), suggest that the Ba Estuary area is a critical habitat for multiple species that are classified as “Near Threatened” or “Endangered.” Specifically, the area likely acts as a parturition ground over the studied period, and potentially as a subsequent nursery area. We identified subareas of high abundance and found that temperature, salinity and depth acted as small‐scale environmental drivers of shark abundance. The data suggests a tendency for species‐specific spatial use, both horizontally (i.e., between sampling areas) and vertically (i.e., across the water column). These results enhance the understanding of shark ecology in Fiji and provide a scientific basis for the implementation of local conservation strategies that contribute to the protection of these threatened species.
Tom Vierus; Stefan Gehrig; Juerg M. Brunnschweiler; Kerstin Glaus; Martin Zimmer; Amandine D. Marie; Ciro Rico. Discovery of a multispecies shark aggregation and parturition area in the Ba Estuary, Fiji Islands. Ecology and Evolution 2018, 8, 7079 -7093.
AMA StyleTom Vierus, Stefan Gehrig, Juerg M. Brunnschweiler, Kerstin Glaus, Martin Zimmer, Amandine D. Marie, Ciro Rico. Discovery of a multispecies shark aggregation and parturition area in the Ba Estuary, Fiji Islands. Ecology and Evolution. 2018; 8 (14):7079-7093.
Chicago/Turabian StyleTom Vierus; Stefan Gehrig; Juerg M. Brunnschweiler; Kerstin Glaus; Martin Zimmer; Amandine D. Marie; Ciro Rico. 2018. "Discovery of a multispecies shark aggregation and parturition area in the Ba Estuary, Fiji Islands." Ecology and Evolution 8, no. 14: 7079-7093.
At least two thirds of all ecosystems worldwide have been impacted and changed severely by human activity (MEA Millennium ecosystem assessment – ecosystems and human well-being: biodiversity synthesis. World Resources Institute, Washington, DC, 2005), mostly without considering consequences for the structure, functioning or service-provisioning of these ecosystems. The societal challenges arising from this are twofold: conserving natural heritage and resources, and at the same time providing and sustaining valuable livelihood and well-being for mankind. Once we missed the chance of preserving an ecosystem from degradation through conservation, restoration is the attempt to repair (i.e., bringing back to a past state) or otherwise enhance (i.e., promoting remaining components and structures) the function of an ecosystem that has been impacted (Suding KN, Annu Rev Ecol Evol Syst 42:465–87, 2011) into a state that warrants historical continuity (Murcia C et al., Trends Ecol Evol 29:548–553, 2014) and closely resembles natural conditions. Nevertheless, most restoration efforts lack a clear aim, and monitoring is rarely considered. Hence, an evaluation of restoration success is difficult, if not impossible. As an alternative to restoration, a new five-step concept of directed design for novel ecosystems (sensu Hobbs RJ, Arico S, Aronson J, Baron JS, Bridgewater P, Cramer VA, Epstein PR, Ewel JJ, Klink CA, Lugo AE, Norton D, Ojima D, Richardson DM, Sanderson EW, Valladares F, Vilà M, Zamora R, Zobel M et al., Glob Ecol Biogeogr 15:1–7, 2006; Morse NB, Pellissier PA, Cianciola EN, Brereton RL, Sullivan MM, Shonka NK, Wheeler TB, McDowell WH et al., Ecol Soc 19:12–21, 2014) with defined functions and services is presented in this chapter. Recent advances in restoration ecology pledge for accepting unintended novel ecosystems as valuable providers of ecosystem services in restoration efforts (Perring MP, Standish RJ, Hobbs RJ et al., Ecol Process 2:18–25, 2013; Abelson A, Halpern B, Reed DC, Orth RJ, Kendrick GA, Beck MW, Belmaker J, Krause G, Edgar GJ, Airoldi L, Brokovich E, France R, Shashar N, De Blaeij A, Stambler N, Salameh P, Shechter M, Nelson PA et al., Bio Sci 66:156–163, 2016). Ecosystem Design develops this idea further to intendedly designing novel ecosystems with the aim of providing particular services that are locally or regionally required for the well-being of mankind. Thus, in contrast to conventional restoration, Ecosystem Design places humans and their needs in the center of action. For this, Ecosystem Design first assesses local and regional needs for ecosystem services to be provided. Second, Ecosystem Design defines a set of these services as goals for the establishment of a functioning ecosystem in a degraded area. In a third step, a toolbox of information on species characteristics and requirements, as well as on the species-specific contributions to service-provisioning, including interspecific interactions...
Martin Zimmer. Ecosystem Design: When Mangrove Ecology Meets Human Needs. Coastal Wetlands: Alteration and Remediation 2018, 367 -376.
AMA StyleMartin Zimmer. Ecosystem Design: When Mangrove Ecology Meets Human Needs. Coastal Wetlands: Alteration and Remediation. 2018; ():367-376.
Chicago/Turabian StyleMartin Zimmer. 2018. "Ecosystem Design: When Mangrove Ecology Meets Human Needs." Coastal Wetlands: Alteration and Remediation , no. : 367-376.
The conservation of functioning ecosystems worldwide is warranted by the need for reliable and sustainable provision of ecosystem services locally, regionally and globally. Mangroves provide numerous ecosystem services both to local human communities, e.g., coastal protection or food security, and to mankind worldwide, e.g., climate change-mitigation. Nonetheless they still lack protection in many places of occurrence. Here we base spatial prioritization and planning of mangrove conservation on functional biodiversity and service-relevant ecosystem processes, being studied through cutting-edge genetic and chemical analyses of sediments to unravel the links between biodiversity, biotic interactions, ecosystem processes and ecosystem services. We nonetheless recommend multidisciplinary approaches when planning protected area networks for the sustainable use and provision of ecosystem services and pledge for (i) considering and prioritizing societal, biological and economic values of mangroves, (ii) integrating adjacent ecosystems to maintain connectivity, and (iii) taking into account the spatial and temporal dynamics of mangrove ecosystems and their community composition under global change, i.e. changes in the spatial distribution of species and services over time. Beyond the example of mangroves and the turnover of organic matter in mangrove sediments described herein, our approach to spatial conservation prioritization and planning is applicable to any other ecosystems and their services.
Véronique Helfer; Martin Zimmer. High-Throughput Techniques As Support for Knowledge-Based Spatial Conservation Prioritization in Mangrove Ecosystems. Coastal Wetlands: Alteration and Remediation 2018, 539 -554.
AMA StyleVéronique Helfer, Martin Zimmer. High-Throughput Techniques As Support for Knowledge-Based Spatial Conservation Prioritization in Mangrove Ecosystems. Coastal Wetlands: Alteration and Remediation. 2018; ():539-554.
Chicago/Turabian StyleVéronique Helfer; Martin Zimmer. 2018. "High-Throughput Techniques As Support for Knowledge-Based Spatial Conservation Prioritization in Mangrove Ecosystems." Coastal Wetlands: Alteration and Remediation , no. : 539-554.
Aline Ferreira de Quadros; Martin Zimmer. Aboveground macrodetritivores and belowground soil processes: Insights on species redundancy. Applied Soil Ecology 2018, 124, 83 -87.
AMA StyleAline Ferreira de Quadros, Martin Zimmer. Aboveground macrodetritivores and belowground soil processes: Insights on species redundancy. Applied Soil Ecology. 2018; 124 ():83-87.
Chicago/Turabian StyleAline Ferreira de Quadros; Martin Zimmer. 2018. "Aboveground macrodetritivores and belowground soil processes: Insights on species redundancy." Applied Soil Ecology 124, no. : 83-87.
Samir M. Aljbour; Martin Zimmer; Andreas Kunzmann. Cellular respiration, oxygen consumption, and trade-offs of the jellyfish Cassiopea sp. in response to temperature change. Journal of Sea Research 2017, 128, 92 -97.
AMA StyleSamir M. Aljbour, Martin Zimmer, Andreas Kunzmann. Cellular respiration, oxygen consumption, and trade-offs of the jellyfish Cassiopea sp. in response to temperature change. Journal of Sea Research. 2017; 128 ():92-97.
Chicago/Turabian StyleSamir M. Aljbour; Martin Zimmer; Andreas Kunzmann. 2017. "Cellular respiration, oxygen consumption, and trade-offs of the jellyfish Cassiopea sp. in response to temperature change." Journal of Sea Research 128, no. : 92-97.
Pathways and rates of decomposition of detrital matter partly depend on its chemical composition. Digestive processes of detritivores drive changes in the chemical composition of detritus, and these changes translate into the chemical composition of the organic matter sequestered into soils and sediments. The latter, in turn, determines how stable organic matter stocks are towards further decay and release of climate-active gases thereupon. We used metabolic fingerprinting to monitor changes in the chemical composition of mangrove detritus upon digestion by a mangrove crab. According to analyses through pyrolysis-GC/MS, the decaying leaf litter of three mangrove species of the Indo-West Pacific, Bruguiera gymnorhiza (L.) Savigny ex Lam. and Poiret 1798, Ceriops tagal (Perr.) C.B. Robinson 1908, and Rhizophora mucronata Lam. 1804, clearly differed from each other in their chemical signature. The feces of detritivorous crabs (Sesarma bidens de Haan 1835) feeding on these detrital sources differed from the source litter in their chemical composition, obviously owing to digestive processes. However, the chemical signatures of feces were more similar to those of their source litter than to those of feces from different litter sources, indicating that the origin of organic matter can be tracked in fecal material. Moreover, male and female crabs appear to exhibit sex-specific digestive processes, as they produced feces that clearly differed from each other in their chemical signature. The 15 chemical compounds most relevant for distinguishing litter sources and fecal material provide first hints on which compounds discriminate the different tree species and characterize digestion by S. bidens. For instance, coumaran (dihydro-benzofuran), indicative of certain carbohydrates, was abundant as a pyrolysis product of the litter of R. mucronata and, to a much lesser degree, C. tagal. Hence, the carbohydrates that were pyrolysed into coumaran seem to discriminate the former two litter sources. Similarly, a pyrolysis-derivate of plant phenolics or proteins, discriminated C. tagal from the other litter sources. From this, we conclude that even subtle differences in litter chemistry and digestive processes of detritivores can be characterized and followed with high resolution through (py-)GC/MS. Further, we propose that the origin of fecal material can be identified with the aid of this technique, and we are currently studying whether the origin of organic matter in the sediment can also be inferred from (py-)GC/MS-data.
Tarek Bakkar; Véronique Helfer; Raika Himmelsbach; Martin Zimmer. Chemical changes in detrital matter upon digestive processes in a sesarmid crab feeding on mangrove leaf litter. Hydrobiologia 2017, 803, 307 -315.
AMA StyleTarek Bakkar, Véronique Helfer, Raika Himmelsbach, Martin Zimmer. Chemical changes in detrital matter upon digestive processes in a sesarmid crab feeding on mangrove leaf litter. Hydrobiologia. 2017; 803 (1):307-315.
Chicago/Turabian StyleTarek Bakkar; Véronique Helfer; Raika Himmelsbach; Martin Zimmer. 2017. "Chemical changes in detrital matter upon digestive processes in a sesarmid crab feeding on mangrove leaf litter." Hydrobiologia 803, no. 1: 307-315.
EnglishFrenchAbstractThe study of the spatiotemporal distribution of talitrid amphipods was carried out along a transect in three stations belonging to the lagoon complex of Ghar El Melh, namely the supralittoral zones of the old harbour of Ghar El Melh, the opposite to Boughaz and Sidi Ali Mekki lagoon. Four species belonging to Talitridae family with two different genera were identified at all stations. These species are Orchestia gammarellus, Orchestia mediterranea, Orchestia stephenseni and Platorchestia platensis. The first two species were collected during the four seasons. The study of the density showed that the most important global mean density in talitrid was found in the supralittoral zone of opposite to Boughaz. In addition, statistical analysis showed a significant difference in the seasonal distribution of amphipods based on plant associations. Furthermore, the highest diversity of talitrid was observed in the winter in the supralittoral zone of opposite to Boughaz and in summer in the supralittoral zones of Sidi Ali Mekki lagoon and the old harbour of Ghar El Melh. Results showed that at all stations, a highly significant correlation of amphipod community with Cymodocea banquette was observed. Moreover, principal component analysis showed that the distribution of the different species depends on climatic and edaphic factors.RésuméL’étude de la distribution spatio-temporelle des Amphipodes Talitridae a été réalisée le long d'un transect, dans trois stations appartenant au complexe lagunaire de Ghar El Melh, à savoir les zones supralittorales du vieux port de Ghar El Melh, de face Boughaz et de la lagune de Sidi Ali Mekki. Au niveau de ces stations, quatre espèces appartenant à deux genres différents et à la famille des Talitridae ont été identifiées. Ces espèces sont: Orchestia gammarellus, Orchestia mediterranea, Orchestia stephenseni et Platorchestia platensis. Les deux premières espèces ont été collectées durant les quatre saisons. L’étude de la densité a permis de mettre en évidence que la densité moyenne globale la plus élevée a été trouvée au niveau de la zone supralittorale de face Boughaz. De plus, en se basant sur les associations végétales, les analyses statistiques ont révélé une différence significative de la distribution saisonnière des Amphipodes. Par ailleurs, la diversité des talitridés la plus importante a été enregistrée en hiver dans la zone supralittorale de face Boughaz et en été dans les zones supralittorales de la lagune de Sidi Ali Mekki et de l'ancien port de Ghar El Melh. D'autre part, nos résultats montrent qu'au niveau de ces trois stations, une corrélation hautement significative entre le peuplement d'Amphipodes et les banquettes de Cymodocea a été observée. L'analyse en composante principale a montré que la distribution des différentes espèces dépend aussi bien des facteurs climatiques qu’édaphiques.
Raja Jelassi; Dieter Garbe‐Schönberg; Karima Nasri‐Ammar; Hajer Khemaissia; Martin Zimmer. Influence of environmental conditions on the distribution of Amphipoda, Talitridae, in the lagoon complex of Ghar El Melh (north-east of Tunisia). African Journal of Ecology 2017, 55, 451 -464.
AMA StyleRaja Jelassi, Dieter Garbe‐Schönberg, Karima Nasri‐Ammar, Hajer Khemaissia, Martin Zimmer. Influence of environmental conditions on the distribution of Amphipoda, Talitridae, in the lagoon complex of Ghar El Melh (north-east of Tunisia). African Journal of Ecology. 2017; 55 (4):451-464.
Chicago/Turabian StyleRaja Jelassi; Dieter Garbe‐Schönberg; Karima Nasri‐Ammar; Hajer Khemaissia; Martin Zimmer. 2017. "Influence of environmental conditions on the distribution of Amphipoda, Talitridae, in the lagoon complex of Ghar El Melh (north-east of Tunisia)." African Journal of Ecology 55, no. 4: 451-464.
Increased human population growth threatens the ecological functioning and goods and services provided by tropical coastal ecosystems. However, a lack of scientific baselines and resources hamper efforts to develop and monitor ecological indicators of environmental change. Citizen science can provide a cost and time effective solution, but needs considerable context specific development to ensure it provides valid information of the quality level required for acceptance by the scientific community. We reviewed the use of sampling methods for shore crabs as an example of an abundant tropical coastal organism with high citizen science suitability and ecological indicator capacity. We propose a hierarchical toolbox based on the distinction between rapid methods, allowing fast, noninvasive sampling by independent citizens, and medium speed methods allowing detailed but more invasive sampling requiring trained citizens working in close interaction with professionals. The hierarchical structure enables full use of the large scale data collection ability of citizen scientists at lower levels, while ensuring validation of errors at higher levels. Additionally, at each level, bias reduction and data validation measures can be employed. We conclude that citizen science methodologies can provide accurate large scale data to develop the ecological baselines urgently needed to monitor and manage environmental change in many tropical coastal ecosystems. We discuss a stepwise implementation of the toolbox leading to accuracy metadata which can be independently reviewed as an ultimate accuracy assessment and data integration mechanism among multiple projects.
Peter Vermeiren; Cynthia C. Munoz; M. Zimmer; Marcus Sheaves. Hierarchical toolbox: Ensuring scientific accuracy of citizen science for tropical coastal ecosystems. Ecological Indicators 2016, 66, 242 -250.
AMA StylePeter Vermeiren, Cynthia C. Munoz, M. Zimmer, Marcus Sheaves. Hierarchical toolbox: Ensuring scientific accuracy of citizen science for tropical coastal ecosystems. Ecological Indicators. 2016; 66 ():242-250.
Chicago/Turabian StylePeter Vermeiren; Cynthia C. Munoz; M. Zimmer; Marcus Sheaves. 2016. "Hierarchical toolbox: Ensuring scientific accuracy of citizen science for tropical coastal ecosystems." Ecological Indicators 66, no. : 242-250.
Current scenarios of global environmental change predict rapid temperature increases, which can directly affect freshwater ecosystems. Leaf litter breakdown in aquatic environments constitutes a fundamental ecosystem process that is mediated by microbial decomposers and animal detritivores. In this study, we examined interactive effects of water temperature (two levels), nutrient concentration (two levels) and grazing pressure by Gammarus pulex (two levels) on breakdown rates of birch leaf litter, biomass and structure of the colonizing microbial community. Litter breakdown rates were stimulated by detritivores, with detritivore effects being enhanced by simultaneously increasing the temperature and adding the nutrients. The interaction between the three factors was synergistic and thus unpredictable from the effects of changes in individual factors. Bacterial community composition was affected by both detritivores and temperature, but less so by nutrient levels and fungal community composition changed upon detritivore activity but was independent of temperature and nutrients. These factors depended on each other in how they affected bacterial communities, but this did not prove true for fungal communities. Relative growth rates of G. pulex were not affected by temperature or nutrient level. We conclude that both abiotic and biotic factors that potentially affect ecosystem processes should be considered simultaneously in studies on effects of environmental change at the community and ecosystem level.
Fatemeh Sanaei Moghadam; Martin Zimmer. Effects of warming, nutrient enrichment and detritivore presence on litter breakdown and associated microbial decomposers in a simulated temperate woodland creek. Hydrobiologia 2015, 770, 243 -256.
AMA StyleFatemeh Sanaei Moghadam, Martin Zimmer. Effects of warming, nutrient enrichment and detritivore presence on litter breakdown and associated microbial decomposers in a simulated temperate woodland creek. Hydrobiologia. 2015; 770 (1):243-256.
Chicago/Turabian StyleFatemeh Sanaei Moghadam; Martin Zimmer. 2015. "Effects of warming, nutrient enrichment and detritivore presence on litter breakdown and associated microbial decomposers in a simulated temperate woodland creek." Hydrobiologia 770, no. 1: 243-256.
Distinct habitats are often linked through fluxes of matter and migration of organisms. In particular, intertidal ecotones are prone to being influenced from both the marine and the terrestrial realms, but whether or not small-scale migration for feeding, sheltering or reproducing is detectable may depend on the parameter studied. Within the ecotone of an upper saltmarsh in the United States, we investigated the sex-specific movement of the semi-terrestrial crab Armases cinereum using an approach of determining multiple measures of across-ecotone migration. To this end, we determined food preference, digestive abilities (enzyme activities), bacterial hindgut communities (genetic fingerprint), and the trophic position of Armases and potential food sources (stable isotopes) of males versus females of different sub-habitats, namely high saltmarsh and coastal forest. Daily observations showed that Armases moved frequently between high-intertidal (saltmarsh) and terrestrial (forest) habitats. Males were encountered more often in the forest habitat, whilst gravid females tended to be more abundant in the marsh habitat but moved more frequently. Food preference was driven by both sex and habitat. The needlerush Juncus was preferred over three other high-marsh detrital food sources, and the periwinkle Littoraria was the preferred prey of male (but not female) crabs from the forest habitats; both male and female crabs from marsh habitat preferred the fiddler crab Uca over three other prey items. In the field, the major food sources were clearly vegetal, but males have a higher trophic position than females. In contrast to food preference, isotope data excluded Uca and Littoraria as major food sources, except for males from the forest, and suggested that Armases consumes a mix of C4 and C3 plants along with animal prey. Digestive enzyme activities differed significantly between sexes and habitats and were higher in females and in marsh crabs. The bacterial hindgut community differed significantly between sexes, but habitat effects were greater than sex effects. By combining multiple measures of feeding ecology, we demonstrate that Armases exhibits sex-specific habitat choice and food preference. By using both coastal forest and saltmarsh habitats, but feeding predominantly in the latter, they possibly act as a key biotic vector of spatial subsidies across habitat borders. The degree of contributing to fluxes of matter, nutrients and energy, however, depends on their sex, indicating that changes in population structure would likely have profound effects on ecosystem connectivity and functioning.
Lena Hübneṙ; Steven C. Pennings; Martin Zimmer. Sex- and habitat-specific movement of an omnivorous semi-terrestrial crab controls habitat connectivity and subsidies: a multi-parameter approach. Oecologia 2015, 178, 999 -1015.
AMA StyleLena Hübneṙ, Steven C. Pennings, Martin Zimmer. Sex- and habitat-specific movement of an omnivorous semi-terrestrial crab controls habitat connectivity and subsidies: a multi-parameter approach. Oecologia. 2015; 178 (4):999-1015.
Chicago/Turabian StyleLena Hübneṙ; Steven C. Pennings; Martin Zimmer. 2015. "Sex- and habitat-specific movement of an omnivorous semi-terrestrial crab controls habitat connectivity and subsidies: a multi-parameter approach." Oecologia 178, no. 4: 999-1015.
Although wetlands were remarkable habitats with their fauna and flora diversity, few studies have been devoted to the study of amphipod distribution in this type of environment. To study both qualitatively and quantitatively amphipod community, surveys were conducted during the spring season in ten coastal lagoons ranging from subhumid to arid bioclimatic stage. At each station, eight quadrats of 50 × 50 cm were randomly placed. Amphipods were preserved in alcohol 70°C. In the laboratory, the specimens collected were identified and counted. Meanwhile, analyses of organic matter, particle size, and heavy metals from the soil taken from each station were made. A total of 1,340 specimens of amphipods were collected, and eight species belonging to Talitridae family were identified. Species richness ranges from one species collected in the supralittoral zone of El Bcherliya (Ghar El Melh lagoon) and eight species in the supralittoral zone of Bizerte lagoon. In this last station, the relative abundance of amphipods was significantly higher (36.04%, N = 483). In addition, the diversity indices of Simpson, Shannon-Weaver, and equitability shows that the highest species diversity characterizes this same station while the community was more balanced in opposite El Boughaz (Ghar El Melh lagoon) (J″ =0.996). Thespatial distribution of different amphipod species depends on edaphic (heavy metals, granulometry, organic matter) and climatic (temperature, humidity) factors.
Raja Jelassi; Hajer Khemaissia; Martin Zimmer; Dieter Garbe-Schönberg; Karima Nasri-Ammar. Biodiversity of Talitridae family (Crustacea, Amphipoda) in some Tunisian coastal lagoons. Zoological Studies 2015, 54, e17 .
AMA StyleRaja Jelassi, Hajer Khemaissia, Martin Zimmer, Dieter Garbe-Schönberg, Karima Nasri-Ammar. Biodiversity of Talitridae family (Crustacea, Amphipoda) in some Tunisian coastal lagoons. Zoological Studies. 2015; 54 (1):e17.
Chicago/Turabian StyleRaja Jelassi; Hajer Khemaissia; Martin Zimmer; Dieter Garbe-Schönberg; Karima Nasri-Ammar. 2015. "Biodiversity of Talitridae family (Crustacea, Amphipoda) in some Tunisian coastal lagoons." Zoological Studies 54, no. 1: e17.
Seawater is a dense microbial suspension with >106 prokaryotic and >104 eukaryotic propagules per milliliter. Hence, submerged surfaces get immediately covered by biofilm-forming colonizers upon contact with seawater. Since biofilms may reduce individual fitness through decreasing motility and attractiveness or increasing shearing stress by water currents and infection risk by pathogens, marine organisms have evolved countermeasures to regulate the number of surface-colonizers; alternatively they tolerate settlement and biofilm-formation. Antimicrobial defense mechanisms co-evolved with potentially colonizing microbes. By contrast, non-native animals (neozoa) are confronted with novel microbial colonizers upon colonizing a new habitat, and are expected to be less well protected against surface-colonization. Here we present results of a thorough screening of the epithelial surface of the ctenophore Mnemiopsis leidyi, being non-native in European marine environments, for epithelial bacteria and archaea. Neither light- and electron-microscopic inspection nor PCR-screening for bacterial and archaeal DNA of 134 adult specimens from different collection sites in the Western Baltic revealed any presence of prokaryotes on the surface epithelium of comb jellies in a recently invaded environment. A limited number of bacterial associates became evident from whole-body extracts of both juvenile and adult comb jellies. Their taxonomic diversity, however, was significantly lower in adult than in juvenile specimens, suggesting a maturation of anti-microbial defense upon ontogenetic development. The mechanisms underlying the effective defense of Mnemiopsisagainst microbial colonization, however, remain unknown. Based on our findings, we propose 1) to make use of invasion events as natural space-for-time experiments on how symbiotic interactions change upon environmental change; and 2) to study basal metazoan animals, such as ctenophores, to understand the evolutionary basics of symbiont-host interactions.
Sven Hammann; Anthony Moss; Martin Zimmer. Sterile Surfaces of Mnemiopsis leidyi (Ctenophora) in Bacterial Suspension—A Key to Invasion Success? Open Journal of Marine Science 2015, 05, 237 -246.
AMA StyleSven Hammann, Anthony Moss, Martin Zimmer. Sterile Surfaces of Mnemiopsis leidyi (Ctenophora) in Bacterial Suspension—A Key to Invasion Success? Open Journal of Marine Science. 2015; 05 (02):237-246.
Chicago/Turabian StyleSven Hammann; Anthony Moss; Martin Zimmer. 2015. "Sterile Surfaces of Mnemiopsis leidyi (Ctenophora) in Bacterial Suspension—A Key to Invasion Success?" Open Journal of Marine Science 05, no. 02: 237-246.