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Ang SBH, Lam WN, Png GK, Tan SKB, Lee BPYH, Khoo M, Luskin MS, Wardle DA, Slade EM. Isopod mouthpart traits respond to a tropical forest recovery gradient. Oecologia 2024; 204:147-159. [PMID: 38151651 DOI: 10.1007/s00442-023-05494-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 11/29/2023] [Indexed: 12/29/2023]
Abstract
Functional trait ecology has the potential to provide generalizable and mechanistic predictions of ecosystem function from data of species distributions and traits. The traits that are selected should both respond to environmental factors and influence ecosystem functioning. Invertebrate mouthpart traits fulfill these criteria, but are seldom collected, lack standardized measurement protocols, and have infrequently been investigated in response to environmental factors. We surveyed isopod species that consume plant detritus, and tree communities in 58 plots across primary and secondary forests in Singapore. We measured body dimensions (body size traits), pereopod and antennae lengths (locomotory traits), dimensions of mandible structures (morphological mouthpart traits), and mechanical advantages generated by mandible shape (mechanical mouthpart traits) for six isopod species found in these plots and investigated if these traits respond to changes in tree community composition, tree diversity, and forest structure. Morphological mouthpart traits responded to a tree compositional gradient reflecting forest recovery degree. Mouthpart features associated with greater consumption of litter (broader but less serrated/rugose lacinia mobilis [an important cutting and chewing structure on the mandible]) were most prevalent in abandoned plantation and young secondary forests containing disturbance-associated tree species. Feeding strategies associated with fungi grazing (narrower and more serrated/rugose lacinia mobilis) were most prevalent in late secondary forests containing later successional tree species. Since morphological mouthpart traits likely also predict consumption and excretion rates of isopods, these traits advance our understanding of environment-trait-ecosystem functioning relationships across contrasting tropical forest plots that vary in composition, disturbance history, and post-disturbance recovery.
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Affiliation(s)
- Shawn B H Ang
- The Asian School of the Environment, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Republic of Singapore
| | - Weng Ngai Lam
- The Asian School of the Environment, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Republic of Singapore.
| | - G Kenny Png
- The Asian School of the Environment, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Republic of Singapore
| | - Sylvia K B Tan
- The Asian School of the Environment, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Republic of Singapore
| | - Benjamin P Y-H Lee
- Singapore Botanic Gardens, National Parks Board 1 Cluny Road, Singapore, 259569, Republic of Singapore
| | - Max Khoo
- Wildlife Management Division, National Parks Board, 1 Cluny Road, Singapore, 259569, Republic of Singapore
| | - Matthew S Luskin
- School of Biological Sciences, The University of Queensland, St. Lucia, QLD, Australia
| | - David A Wardle
- Department of Ecology and Environmental Sciences, Umeå University, Umeå, Sweden
| | - Eleanor M Slade
- The Asian School of the Environment, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Republic of Singapore
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Des Marteaux LE, Kullik SA, Habash M, Schmidt JM. Terrestrial Isopods Porcellio scaber and Oniscus asellus (Crustacea: Isopoda) Increase Bacterial Abundance and Modify Microbial Community Structure in Leaf Litter Microcosms: a Short-Term Decomposition Study. MICROBIAL ECOLOGY 2020; 80:690-702. [PMID: 32440700 DOI: 10.1007/s00248-020-01527-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 05/12/2020] [Indexed: 06/11/2023]
Abstract
Invasive terrestrial isopods are likely to have altered leaf litter decomposition processes in North American forests, but the mechanisms underlying these alterations and the degree to which they differ among isopod species are poorly characterized. Using mixed-deciduous leaf litter microcosms, we quantified the effects of two common, invasive isopods (Oniscus asellus and Porcellio scaber) on short-term leaf litter decomposition and microbial community structure and function. Microcosms containing ground litter and a microbial inoculant were exposed to one of the two isopod species or no isopods for 21 days. Mass loss was then quantified as the change in litter dry mass after leaching, and microbial respiration was quantified as the mass of CO2 absorbed by soda lime. Litter leachates were plated on agar to quantify culturable bacterial and fungal abundance, and denaturing gradient gel electrophoresis of amplified leachate microbial DNA was used to characterize shifts in microbial community structure. Isopod presence increased litter mass loss by a modest ~ 6%, but did not affect litter microbial respiration. Bacterial abundance increased significantly in the presence of isopods, while fungal abundance was either unchanged or reduced. Overall litter microbial species richness was reduced by isopods, with O. asellus specifically reducing fungal abundance and diversity. Isopods modified the microbial community structure by suppressing four bacterial and one fungal species, while promoting growth of four other bacterial species (two unique to each isopod species) and two fungal species (one which was unique to O. asellus).
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Affiliation(s)
- Lauren E Des Marteaux
- School of Environmental Sciences, University of Guelph, Guelph, ON, Canada.
- Graduate School of Science, Osaka City University, Osaka, Japan.
| | - Sigrun A Kullik
- School of Environmental Sciences, University of Guelph, Guelph, ON, Canada
| | - Marc Habash
- School of Environmental Sciences, University of Guelph, Guelph, ON, Canada
| | - Jonathan M Schmidt
- School of Environmental Sciences, University of Guelph, Guelph, ON, Canada
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Patoine G, Bruelheide H, Haase J, Nock C, Ohlmann N, Schwarz B, Scherer‐Lorenzen M, Eisenhauer N. Tree litter functional diversity and nitrogen concentration enhance litter decomposition via changes in earthworm communities. Ecol Evol 2020; 10:6752-6768. [PMID: 32724548 PMCID: PMC7381558 DOI: 10.1002/ece3.6474] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 05/08/2020] [Accepted: 05/18/2020] [Indexed: 11/23/2022] Open
Abstract
Biodiversity is a major driver of numerous ecosystem functions. However, consequences of changes in forest biodiversity remain difficult to predict because of limited knowledge about how tree diversity influences ecosystem functions. Litter decomposition is a key process affecting nutrient cycling, productivity, and carbon storage and can be influenced by plant biodiversity. Leaf litter species composition, environmental conditions, and the detritivore community are main components of the decomposition process, but their complex interactions are poorly understood. In this study, we tested the effect of tree functional diversity (FD) on litter decomposition in a field experiment manipulating tree diversity and partitioned the effects of litter physiochemical diversity and the detritivore community. We used litterbags with different mesh sizes to separate the effects of microorganisms and microfauna, mesofauna, and macrofauna and monitored soil fauna using pitfall traps and earthworm extractions. We hypothesized that higher tree litter FD accelerates litter decomposition due to the availability of complementary food components and higher activity of detritivores. Although we did not find direct effects of tree FD on litter decomposition, we identified key litter traits and macrodetritivores that explained part of the process. Litter mass loss was found to decrease with an increase in leaf litter carbon:nitrogen ratio. Moreover, litter mass loss increased with an increasing density of epigeic earthworms, with most pronounced effects in litterbags with a smaller mesh size, indicating indirect effects. Higher litter FD and litter nutrient content were found to increase the density of surface-dwelling macrofauna and epigeic earthworm biomass. Based on structural equation modeling, we conclude that tree FD has a weak positive effect on soil surface litter decomposition by increasing the density of epigeic earthworms and that litter nitrogen-related traits play a central role in tree composition effects on soil fauna and decomposition.
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Affiliation(s)
- Guillaume Patoine
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
- Institute of BiologyLeipzig UniversityLeipzigGermany
| | - Helge Bruelheide
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
- Institute of Biology/Geobotany and Botanical GardenMartin Luther University Halle‐WittenbergHalle (Saale)Germany
| | - Josephine Haase
- GeobotanyFaculty of BiologyUniversity of FreiburgFreiburgGermany
| | - Charles Nock
- GeobotanyFaculty of BiologyUniversity of FreiburgFreiburgGermany
- Department of Renewable ResourcesFaculty of Agriculture, Life and Environmental SciencesGeneral Services BuildingUniversity of AlbertaEdmontonABCanada
| | - Niklas Ohlmann
- GeobotanyFaculty of BiologyUniversity of FreiburgFreiburgGermany
| | - Benjamin Schwarz
- Biometry and Environmental System AnalysisFaculty of Environment and Natural ResourcesUniversity of FreiburgFreiburgGermany
| | | | - Nico Eisenhauer
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
- Institute of BiologyLeipzig UniversityLeipzigGermany
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Effects of Detritivores on Nutrient Dynamics and Corn Biomass in Mesocosms. INSECTS 2019; 10:insects10120453. [PMID: 31847249 PMCID: PMC6955738 DOI: 10.3390/insects10120453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 11/27/2019] [Accepted: 12/05/2019] [Indexed: 12/03/2022]
Abstract
(1) Background: Strategies aimed at managing freshwater eutrophication should be based on practices that consider cropland invertebrates, climatic change, and soil nutrient cycling. Specifically, detritivores play a crucial role in the biogeochemical processes of soil through their consumptive and burrowing activities. Here, we evaluated the effectiveness of increasing detritivore abundance as a strategy for nutrient management under varied rainfall. (2) Methods: We manipulated soil macroinvertebrate abundance and rainfall amount in an agricultural mesocosms. We then measured the phosphorus, nitrogen, and carbon levels within the soil, corn, invertebrates, and soil solution. (3) Results: Increasing detritivore abundance in our soil significantly increased corn biomass by 2.49 g (p < 0.001), reduced weed growth by 18.2% (p < 0.001), and decreased soil solution nitrogen and total organic carbon (p < 0.05) and volume by 31.03 mL (p < 0.001). Detritivore abundance also displayed a significant interaction effect with rainfall treatment to influence soil total P (p = 0.0019), total N (p < 0.001), and total C (p = 0.0146). (4) Conclusions: Soil detritivores play an important role in soil nutrient cycling and soil health. Incorporating soil macroinvertebrate abundance into management strategies for agricultural soil may increase soil health of agroecosystems, preserve freshwater ecosystems, and protect the valuable services they both provide for humans.
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Tóth Z, Hornung E, Báldi A. Effects of set-aside management on certain elements of soil biota and early stage organic matter decomposition in a High Nature Value Area, Hungary. NATURE CONSERVATION 2018. [DOI: 10.3897/natureconservation.29.24856] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Agricultural intensification is one of the greatest threats to soil biota and function. In contrast, set-aside still remains a management practice in certain agri-environmental schemes. In Hungary, the establishment of sown set-aside fields is a requirement of agri-environmental schemes in High Nature Value Areas. We tested the effects of set-aside management on soil biota (bacteria, microarthropods, woodlice and millipedes), soil properties and organic matter decomposition after an initial establishment period of two years. Cereal – set-aside field pairs, semi-natural grasslands and cereal fields were sampled in the Heves Plain High Nature Value Area in Eastern Hungary, in May 2014. Topsoil samples were taken from each site for physical, chemical, microbial analyses and for extraction of soil microarthropods. Macrodecomposers were sampled by pitfall traps for two weeks. The biological quality of soil was estimated by the integrated QBS index (‘‘Qualità Biologica del Suolo’’, meaning ‘‘Biological Quality of Soil’’) based on diversity of soil microarthropods. To follow early stage organic matter decomposition, we used tea bags filled with a site-independent, universal plant material (Aspalathuslinearis, average mass 1.26 ± 0.03 g). Tea bags were retrieved after 1 month to estimate the rate of mass loss. We found significant differences between habitat types regarding several soil physical and chemical parameters (soil pH, K and Na content). The study showed positive effects of set-aside management on soil biodiversity, especially for microarthropods and isopods. However, we did not experience similar trends in relation to soil bacteria and millipedes. There was higher intensity of organic matter decomposition in soils of set-aside fields and semi-natural grasslands (remaining mass on average: 74.17% and 76.6%, respectively) compared to cereal fields (average remaining mass: 81.3%). Out of the biotic components, only the biological quality of soil significantly influenced (even if marginally) plant tissue decomposition. Our results highlight the importance of set-aside fields as shelter habitats for soil biota, especially for arthropods. Set-aside fields that are out of a crop rotation for 2 years could be a valuable option for maintaining soil biodiversity, as these fields may simultaneously conserve elements of above- and below-ground diversity.
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Patoine G, Thakur MP, Friese J, Nock C, Hönig L, Haase J, Scherer-Lorenzen M, Eisenhauer N. Plant litter functional diversity effects on litter mass loss depend on the macro-detritivore community. PEDOBIOLOGIA 2017; 65:29-42. [PMID: 29180828 PMCID: PMC5701737 DOI: 10.1016/j.pedobi.2017.07.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A better understanding of the mechanisms driving litter diversity effects on decomposition is needed to predict how biodiversity losses affect this crucial ecosystem process. In a microcosm study, we investigated the effects of litter functional diversity and two major groups of soil macro-detritivores on the mass loss of tree leaf litter mixtures. Furthermore, we tested the effects of litter trait community means and dissimilarity on litter mass loss for seven traits relevant to decomposition. We expected macro-detritivore effects on litter mass loss to be most pronounced in litter mixtures of high functional diversity. We used 24 leaf mixtures differing in functional diversity, which were composed of litter from four species from a pool of 16 common European tree species. Earthworms, isopods, or a combination of both were added to each litter combination for two months. Litter mass loss was significantly higher in the presence of earthworms than in that of isopods, whereas no synergistic effects of macro-detritivore mixtures were found. The effect of functional diversity of the litter material was highest in the presence of both macro-detritivore groups, supporting the notion that litter diversity effects are most pronounced in the presence of different detritivore species. Species-specific litter mass loss was explained by nutrient content, secondary compound concentration, and structural components. Moreover, dissimilarity in N concentrations increased litter mass loss, probably because detritivores having access to nutritionally diverse food sources. Furthermore, strong competition between the two macro-detritivores for soil surface litter resulted in a decrease of survival of both macro-detritivores. These results show that the effects of litter functional diversity on decomposition are contingent upon the macro-detritivore community and composition. We conclude that the temporal dynamics of litter trait diversity effects and their interaction with detritivore diversity are key to advancing our understanding of litter mass loss in nature.
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Affiliation(s)
- Guillaume Patoine
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany
- Center for Environmental Research and Technology, General and Theoretical Ecology, University of Bremen, Leobener Str, 28359 Bremen, Germany
| | - Madhav P. Thakur
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany
- Institute of Biology, University of Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany
| | - Julia Friese
- Institute of Ecology, Friedrich Schiller University Jena, Dornburger Strasse 159, 07743 Jena, Germany
| | - Charles Nock
- Department of Silviculture, Faculty of Environment and Natural Resources, University of Freiburg, Tennenbacherstrasse 4, 79106 Freiburg, Germany
- Geobotany, Faculty of Biology, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany
| | - Lydia Hönig
- Institute of Biology, Geobotany and Botanical Garden, Martin Luther University Halle Wittenberg, Am Kirchtor 1, 06108 Halle (Saale), Germany
| | - Josephine Haase
- Geobotany, Faculty of Biology, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany
- Institute for Terrestrial Ecosystems, Department of Environmental Systems Science, ETH Zurich, Universitaetsstrasse 16, 8092 Zurich, Switzerland
| | - Michael Scherer-Lorenzen
- Department of Silviculture, Faculty of Environment and Natural Resources, University of Freiburg, Tennenbacherstrasse 4, 79106 Freiburg, Germany
- Geobotany, Faculty of Biology, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany
| | - Nico Eisenhauer
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany
- Institute of Biology, University of Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany
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CÔtÉ B, Fyles JW. Leaf litter disappearance of hardwood species of southern Québec: Interaction between litter quality and stand type. ECOSCIENCE 2016. [DOI: 10.1080/11956860.1994.11682258] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Barantal S, Schimann H, Fromin N, Hättenschwiler S. C, N and P fertilization in an Amazonian rainforest supports stoichiometric dissimilarity as a driver of litter diversity effects on decomposition. Proc Biol Sci 2015; 281:20141682. [PMID: 25320173 DOI: 10.1098/rspb.2014.1682] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Plant leaf litter generally decomposes faster as a group of different species than when individual species decompose alone, but underlying mechanisms of these diversity effects remain poorly understood. Because resource C : N : P stoichiometry (i.e. the ratios of these key elements) exhibits strong control on consumers, we supposed that stoichiometric dissimilarity of litter mixtures (i.e. the divergence in C : N : P ratios among species) improves resource complementarity to decomposers leading to faster mixture decomposition. We tested this hypothesis with: (i) a wide range of leaf litter mixtures of neotropical tree species varying in C : N : P dissimilarity, and (ii) a nutrient addition experiment (C, N and P) to create stoichiometric similarity. Litter mixtures decomposed in the field using two different types of litterbags allowing or preventing access to soil fauna. Litter mixture mass loss was higher than expected from species decomposing singly, especially in presence of soil fauna. With fauna, synergistic litter mixture effects increased with increasing stoichiometric dissimilarity of litter mixtures and this positive relationship disappeared with fertilizer addition. Our results indicate that litter stoichiometric dissimilarity drives mixture effects via the nutritional requirements of soil fauna. Incorporating ecological stoichiometry in biodiversity research allows refinement of the underlying mechanisms of how changing biodiversity affects ecosystem functioning.
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Affiliation(s)
- Sandra Barantal
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE UMR 5175, CNRS-Université de Montpellier-Université Paul-Valéry Montpellier-EPHE), 1919 Route de MENDE, 34293 Montpellier Cedex 5, France Ecology of Guiana Forest ECOFOG UMR 745, INRA-CIRAD-CNRS-UAG-AgroParisTech, INRA Campus Agronomique, BP 16, Kourou Cedex 97310, France Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - Heidy Schimann
- Ecology of Guiana Forest ECOFOG UMR 745, INRA-CIRAD-CNRS-UAG-AgroParisTech, INRA Campus Agronomique, BP 16, Kourou Cedex 97310, France
| | - Nathalie Fromin
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE UMR 5175, CNRS-Université de Montpellier-Université Paul-Valéry Montpellier-EPHE), 1919 Route de MENDE, 34293 Montpellier Cedex 5, France
| | - Stephan Hättenschwiler
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE UMR 5175, CNRS-Université de Montpellier-Université Paul-Valéry Montpellier-EPHE), 1919 Route de MENDE, 34293 Montpellier Cedex 5, France
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Leaf litter quality drives litter mixing effects through complementary resource use among detritivores. Oecologia 2013; 173:269-80. [PMID: 23292458 DOI: 10.1007/s00442-012-2588-1] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 12/20/2012] [Indexed: 10/27/2022]
Abstract
To comprehend the potential consequences of biodiversity loss on the leaf litter decomposition process, a better understanding of its underlying mechanisms is necessary. Here, we hypothesize that positive litter mixture effects occur via complementary resource use, when litter species complement each other in terms of resource quality for detritivores. To investigate this, monocultures and mixtures of two leaf litter species varying in quality were allowed to decompose with and without a single macro-detritivore species (the terrestrial woodlice Oniscus asellus). Resource quality of the mixture was assessed by the mean concentration, the dissimilarity in absolute and relative concentrations, and the covariance between nitrogen (N), phosphorus (P) and calcium (Ca) supply. Our results clearly show that litter mixing effects were driven by differences in their resource quality for detritivores. In particular, complementary supply of N and P was a major driver of litter mixing effects. Interestingly, litter mixing effects caused by the addition of woodlice were predominantly driven by N dissimilarity, whereas in their absence, increased P concentration was the main driver of litter mixing effects. These results show that ultimately, litter diversity effects on decomposition may be driven by complementary resource use of the whole decomposer community (i.e., microbes and macro-detritivores).
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Vos VCA, van Ruijven J, Berg MP, Peeters ETHM, Berendse F. Macro-detritivore identity drives leaf litter diversity effects. OIKOS 2010. [DOI: 10.1111/j.1600-0706.2010.18650.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Quadros AF, Araujo PB. An assemblage of terrestrial isopods (Crustacea) in southern Brazil and its contribution to leaf litter processing. ACTA ACUST UNITED AC 2008. [DOI: 10.1590/s0101-81752008000100009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We present an assemblage of terrestrial isopods in Parque Estadual de Itapuã, southern Brazil, and estimate the contribution of two species to the leaf litter processing. After one year of sampling, we obtained 3748 individuals of six species and four eco-morphologic groups (in order of abundance): Balloniscus glaber Araujo & Zardo, 1995, Atlantoscia floridana (van Name, 1940), Pseudodiploexochus tabularis (Giambiagi de Calabrese, 1939), Trichorhina sp., Alboscia itapuensis Araujo & Quadros, 2005 and Novamundoniscus gracilis Lopes & Araujo, 2003. Total monthly density corresponded to 368 individuals per square meter. The species A. itapuensis and N. gracilis represented less than 1% of total individuals. All the others showed aggregated distribution. Atlantoscia floridana and B. glaber had the highest proportion of individuals occurring together (88%) and a significant species association. Their monthly biomass averaged 4.92 kg ha-1 for B. glaber and 0.97 kg ha-1 for A. floridana. Consumption rates, obtained in the lab (in mg mg-1 day-1) were 0.34 ± 0.04 and 0.70 ± 0.18 for B. glaber and A. floridana, respectively and assimilation efficiency was about 30%. We estimated that both species together could process 860 kg leaves ha-1 year-1.
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Zimmer M. Nutrition in terrestrial isopods (Isopoda: Oniscidea): an evolutionary-ecological approach. Biol Rev Camb Philos Soc 2002; 77:455-93. [PMID: 12475050 DOI: 10.1017/s1464793102005912] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The nutritional morphology, physiology and ecology of terrestrial isopods (Isopoda: Oniscidea) is significant in two respects. (1) Most oniscid isopods are truly terrestrial in terms of being totally independent of the aquatic environment. Thus, they have evolved adaptations to terrestrial food sources. (2) In many terrestrial ecosystems, isopods play an important role in decomposition processes through mechanical and chemical breakdown of plant litter and by enhancing microbial activity. While the latter aspect of nutrition is discussed only briefly in this review, I focus on the evolutionary ecology of feeding in terrestrial isopods. Due to their possessing chewing mouthparts, leaf litter is comminuted prior to being ingested, facilitating both enzymatic degradation during gut passage and microbial colonization of egested faeces. Digestion of food through endogenous enzymes produced in the caeca of the midgut glands (hepatopancreas) and through microbial enzymes, either ingested along with microbially colonized food or secreted by microbial endosymbionts, mainly takes place in the anterior part of the hindgut. Digestive processes include the activity of carbohydrases, proteases, dehydrogenases, esterases, lipases, arylamidases and oxidases, as well as the nutritional utilization of microbial cells. Absorption of nutrients is brought about by the hepatopancreas and/or the hindgut epithelium, the latter being also involved in osmoregulation and water balance. Minerals and metal cations are effectively extracted from the food, while overall assimilation efficiencies may be low. Heavy metals are stored in special organelles of the hepatopancreatic tissue. Nitrogenous waste products are excreted via ammonia in its gaseous form, with only little egested along with the faeces. Nonetheless, faeces are characterized by high nitrogen content and provide a favourable substrate for microbial colonization and growth. The presence of a dense microbial population on faecal material is one reason for the coprophagous behaviour of terrestrial isopods. For the same reason, terrestrial isopods prefer feeding on decaying rather than fresh leaf litter, the former also being more palatable and easier to digest. Acceptable food sources are detected through distance and contact chemoreceptors. The 'quality' of the food source determines individual growth, fecundity and mortality, and thus maintenance at the population level. Due to their physiological adaptations to feeding on and digesting leaf litter, terrestrial isopods contribute strongly to nutrient recycling during decomposition processes. Yet, many of these adaptations are still not well understood.
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Affiliation(s)
- Martin Zimmer
- Zoologisches Institut: Limnologie, Biologiezentrum der Christian-Albrechts-Universität zu Kiel, Kiel, Germany.
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Kaspariz M, Yanovlak SP. Bait Use in Tropical Litter and Canopy Ants-Evidence of Differences in Nutrient Limitation1. Biotropica 2001. [DOI: 10.1111/j.1744-7429.2001.tb00172.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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14
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Kaspari M, Yanoviak SP. Bait Use in Tropical Litter and Canopy Ants—Evidence of Differences in Nutrient Limitation1. Biotropica 2001. [DOI: 10.1646/0006-3606(2001)033[0207:buitla]2.0.co;2] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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15
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Pennings SC, Carefoot TH, Zimmer M, Danko JP, Ziegler A. Feeding preferences of supralittoral isopods and amphipods. CAN J ZOOL 2000. [DOI: 10.1139/z00-143] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We examined the feeding preferences of 3 supralittoral crustacean species in the Pacific Northwest of North America. The isopod Ligia pallasii (Brandt, 1833), the rocky-shore amphipod Traskorchestia traskiana (Stimpson, 1857), and the sandy-beach amphipod Megalorchestia californiana (Brandt, 1851) had similar feeding preferences, suggesting that feeding preferences were based on general algal traits rather than on adaptations particular to specific herbivores. No single trait clearly distinguished low- and high-preference seaweeds, although pH and phenolic compounds may have been important for two chemically defended seaweeds (Desmarestia sp. and Fucus sp., respectively). Feeding preferences of L. pallasii were affected by dietary history, but effects were minor compared with differences among seaweeds. All 3 consumers tended to prefer wrack (aged, stranded seaweeds) over fresh seaweeds of the same species. Our results suggested that increased organic and mineral contents of wrack were important in mediating these preferences, but that toughness and salt and nitrogen contents were not. Reduced levels of defensive compounds may have made wrack more palatable than fresh seaweeds in the case of the two chemically defended seaweeds.
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