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Yang J, Lu J, Yang Y, Tian K, Kong X, Tian X, Scheu S. Earthworms neutralize the influence of components of particulate pollutants on soil extracellular enzymatic functions in subtropical forests. PeerJ 2023; 11:e15720. [PMID: 37551350 PMCID: PMC10404396 DOI: 10.7717/peerj.15720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 06/16/2023] [Indexed: 08/09/2023] Open
Abstract
Human activities are increasing the input of atmospheric particulate pollutants to forests. The components of particulate pollutants include inorganic anions, base cations and hydrocarbons. Continuous input of particulate pollutants may affect soil functioning in forests, but their effects may be modified by soil fauna. However, studies investigating how soil fauna affects the effects of particulate pollutants on soil functioning are lacking. Here, we investigated how earthworms and the particulate components interact in affecting soil enzymatic functions in a deciduous (Quercus variabilis) and a coniferous (Pinus massoniana) forest in southeast China. We manipulated the addition of nitrogen (N, ammonium nitrate), sodium (Na, sodium chloride) and polycyclic aromatic hydrocarbons (PAHs, five mixed PAHs) in field mesocosms with and without Eisenia fetida, an earthworm species colonizing forests in eastern China. After one year, N and Na addition increased, whereas PAHs decreased soil enzymatic functions, based on average Z scores of extracellular enzyme activities. Earthworms generally stabilized soil enzymatic functions via neutralizing the effects of N, Na and PAHs addition in the deciduous but not in the coniferous forest. Specifically, earthworms neutralized the effects of N and Na addition on soil pH and the effects of the addition of PAHs on soil microbial biomass. Further, both particulate components and earthworms changed the correlations among soil enzymatic and other ecosystem functions in the deciduous forest, but the effects depended on the type of particulate components. Generally, the effects of particulate components and earthworms on soil enzymatic functions were weaker in the coniferous than the deciduous forest. Overall, the results indicate that earthworms stabilize soil enzymatic functions in the deciduous but not the coniferous forest irrespective of the type of particulate components. This suggests that earthworms may neutralize the influence of atmospheric particulate pollutants on ecosystem functions, but the neutralization may be restricted to deciduous forests.
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Affiliation(s)
- Junbo Yang
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu Province, China
- Johann Friedrich Blumenbach Institute of Zoology and Anthropology, University of Göttingen, Göttingen, Lower Saxony, Germany
| | - Jingzhong Lu
- Johann Friedrich Blumenbach Institute of Zoology and Anthropology, University of Göttingen, Göttingen, Lower Saxony, Germany
| | - Yinghui Yang
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu Province, China
| | - Kai Tian
- College of Life Science and Agricultural Engineering, Nanyang Normal University, Nanyang, Henan Province, China
| | - Xiangshi Kong
- Key Laboratory for Ecotourism of Hunan Province, School of Tourism and Management Engineering, Jishou University, Jishou, Hunan Province, China
| | - Xingjun Tian
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu Province, China
- College of Eco-Environmental Engineering, Qinghai University, Xining, Qinghai Province, China
| | - Stefan Scheu
- Johann Friedrich Blumenbach Institute of Zoology and Anthropology, University of Göttingen, Göttingen, Lower Saxony, Germany
- Centre of Biodiversity and Sustainable Land Use, University of Göttingen, Göttingen, Lower Saxony, Germany
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2
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Bruand A, Reatto A, Brossard M, Jouquet P, de Souza Martins É. Long-term activity of social insects responsible for the physical fertility of soils in the tropics. Sci Rep 2023; 13:12337. [PMID: 37524990 PMCID: PMC10390474 DOI: 10.1038/s41598-023-39654-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 07/28/2023] [Indexed: 08/02/2023] Open
Abstract
Ferralsols correspond to the red and yellow soils that are common in the tropics. They are deeply weathered but physical fertility is high because they exhibit a strong microgranular structure whose origin is still actively debated. In the present study, we looked for evidence of the biological origin of the structure resulting from soil fauna activity. We present results recorded with Brazilian Ferralsols developed under native vegetation. It was found that the Ferralsols studied exhibit morphological features related to the activity of social insects. We showed the presence of potassium 2:1 clays originating from the saprolite in the microaggregates of all the Ferralsols studied. These 2:1 clays were earlier discussed as markers of long-term termite activity. This highlights the threat that weighs on the physical fertility of these soils, and more broadly on the water cycle in the tropical regions concerned, if intensive agriculture reduces the soil fauna biodiversity, as indicated by several studies.
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Affiliation(s)
- Ary Bruand
- Institut des Sciences de la Terre d'Orléans (ISTO), UMR7327, UO, CNRS, BRGM, Observatoire des Sciences de l'Univers en région Centre (OSUC), Université d'Orléans, 1A Rue de la Férollerie, 45071, Orléans, Cedex 2, France.
| | - Adriana Reatto
- Secretaria de Pesquisa e Desenvolvimento, Empresa Brasileira de Pesquisa Agropecuária (Embrapa), Parque Estação Biológica-PqEB s/no, Brasília, DF, Brazil
| | - Michel Brossard
- Institut de Recherche pour le Développement (IRD), Eco&Sols, UMR IRD, INRAE, CIRAD, Institut Agro, University of Montpellier, Montpellier, France
| | - Pascal Jouquet
- Institut de Recherche pour le Développement (IRD), Institute of Ecology and Environmental Sciences of Paris (iEES Paris), UPEC, CNRS, IRD, INRAE, UMR Sorbonne Université, Paris, France
| | - Éder de Souza Martins
- Empresa Brasileira de Pesquisa Agropecuária (Embrapa Cerrados), Brasília, DF, Brasil
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3
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Reeves JT, Herzog C, Barnes CL, Davis CA, Fuhlendorf SD, Wilder SM. Variation among arthropod taxa in the amino acid content of exoskeleton and digestible tissue. Ecol Evol 2023; 13:e10348. [PMID: 37496760 PMCID: PMC10365971 DOI: 10.1002/ece3.10348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 07/04/2023] [Accepted: 07/10/2023] [Indexed: 07/28/2023] Open
Abstract
Arthropod consumption provides amino acids to invertebrates and vertebrates alike, but not all amino acids in arthropods may be digestible as some are bound in the exoskeleton. Consumers may not be able to digest exoskeleton in significant amounts or avoid it entirely (e.g., extraoral digestion). Hence, measures that do not separate digestible amino acids from those in exoskeleton may not accurately represent the amino acids available to consumers. Additionally, arthropods are taxonomically diverse, and it remains unclear if taxonomic differences also reflect differences in amino acid availability. Thus, we tested: (1) if there were consistent differences in the content and balance of amino acids between the digestible tissue and exoskeleton of arthropods and (2) if arthropod Orders differ in amino acid content and balance. We measured the amino acid content (mg/100 mg dry mass) and balance (mg/100 mg protein) of whole bodies and exoskeleton of a variety of arthropods using acid hydrolysis. Overall, there was higher amino acid content in digestible tissue. There were also significant differences in the amino acid balance of proteins in digestible tissue and exoskeleton. Amino acid content and balance also varied among Orders; digestible tissues of Hemiptera contained more of some essential amino acids than other Orders. These results demonstrate that arthropod taxa vary in amino acid content, which could have implications for prey choice by insectivores. In addition, exoskeleton and digestible tissue content differ in arthropods, which means that whole body amino acid content of an arthropod is not necessarily a predictor of amino acid intake of a predator that feeds on that arthropod.
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Affiliation(s)
- J. T. Reeves
- Department of Integrative BiologyOklahoma State UniversityStillwaterOklahomaUSA
| | - Colton Herzog
- Department of Integrative BiologyOklahoma State UniversityStillwaterOklahomaUSA
| | | | - Craig A. Davis
- Department of Natural Resource Ecology and ManagementOklahoma State UniversityStillwaterOklahomaUSA
| | - Samuel D. Fuhlendorf
- Department of Natural Resource Ecology and ManagementOklahoma State UniversityStillwaterOklahomaUSA
| | - Shawn M. Wilder
- Department of Integrative BiologyOklahoma State UniversityStillwaterOklahomaUSA
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4
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Wang Y, Wu F, Wu Q, Yue K, Yuan J, Yuan C, Peng Y. Global characteristics and drivers of sodium and aluminum concentrations in freshly fallen plant litter. FRONTIERS IN PLANT SCIENCE 2023; 14:1174697. [PMID: 37384364 PMCID: PMC10293839 DOI: 10.3389/fpls.2023.1174697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/23/2023] [Indexed: 06/30/2023]
Abstract
Plant litter is not only the major component of terrestrial ecosystem net productivity, the decomposition of which is also an important process for the returns of elements, including sodium (Na) and aluminum (Al), which can be beneficial or toxic for plant growth. However, to date, the global characteristics and driving factors of Na and Al concentrations in freshly fallen litter still remain elusive. Here, we evaluated the concentrations and drivers of litter Na and Al with 491 observations extracted from 116 publications across the globe. Results showed that (1) the average concentrations of Na in leaf, branch, root, stem, bark, and reproductive tissue (flowers and fruits) litter were 0.989, 0.891, 1.820, 0.500, 1.390, and 0.500 g/kg, respectively, and the concentrations of Al in leaf, branch, and root were 0.424, 0.200 and 1.540 g/kg, respectively. (2) mycorrhizal association significantly affected litter Na and Al concentration. The highest concentration of Na was found in litter from trees associated with both arbuscular mycorrhizal fungi (AM) and ectomycorrhizal fungi (ECM), followed by litter from trees with AM and ECM. Lifeform, taxonomic, and leaf form had significant impacts on the concentration of Na and Al in plant litter of different tissues. (3) leaf litter Na concentration was mainly driven by mycorrhizal association, leaf form and soil phosphorus concentration, while leaf litter Al concentration was mainly controlled by mycorrhizal association, leaf form, and precipitation in the wettest month. Overall, our study clearly assessed the global patterns and influencing factors of litter Na and Al concentrations, which may help us to better understand their roles in the associated biogeochemical cycles in forest ecosystem.
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Affiliation(s)
- Yiqing Wang
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, School of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Fuzhong Wu
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, School of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Qiqian Wu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, Zhejiang, China
| | - Kai Yue
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, School of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Ji Yuan
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, School of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Chaoxiang Yuan
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, School of Geographical Sciences, Fujian Normal University, Fuzhou, China
| | - Yan Peng
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, School of Geographical Sciences, Fujian Normal University, Fuzhou, China
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5
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Shephard AM, Knudsen K, Snell-Rood EC. Anthropogenic sodium influences butterfly responses to nitrogen-enriched resources: implications for the nitrogen limitation hypothesis. Oecologia 2023; 201:941-952. [PMID: 36971819 DOI: 10.1007/s00442-023-05366-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 03/20/2023] [Indexed: 03/29/2023]
Abstract
Humans are increasing the environmental availability of historically limited nutrients, which may significantly influence organismal performance and behavior. Beneficial or stimulatory responses to increases in nitrogen availability (i.e., nitrogen limitation) are generally observed in plants but less consistently in animals. One possible explanation is that animal responses to nitrogen enrichment depend on how nitrogen intake is balanced with sodium, a micronutrient crucial for animals but not plants. We tested this idea in the cabbage white butterfly (Pieris rapae), a species that frequently inhabits nutrient-enriched plants in agricultural settings and roadside verges. We asked (1) whether anthropogenic increases in sodium influence how nitrogen enrichment affects butterfly performance and (2) whether individuals can adaptively adjust their foraging behavior to such effects. Larval nitrogen enrichment enhanced growth of cabbage white larvae under conditions of low but not high sodium availability. In contrast, larval nitrogen enrichment increased egg production of adult females only when individuals developed with high sodium availability. Ovipositing females preferred nitrogen-enriched leaves regardless of sodium availability, while larvae avoided feeding on nitrogen-enriched leaves elevated in sodium. Our results show that anthropogenic increases in sodium influence whether individuals benefit from and forage on nitrogen-enriched resources. Yet, different nitrogen-to-sodium ratios are required to optimize larval and adult performance. Whether increases in sodium catalyze or inhibit benefits of nitrogen enrichment may depend on how evolved nutrient requirements vary across stages of animal development.
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Affiliation(s)
- Alexander M Shephard
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Twin Cities, 1987 Upper Buford Circle, St. Paul, MN, 55108, USA.
| | - Kyle Knudsen
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Twin Cities, 1987 Upper Buford Circle, St. Paul, MN, 55108, USA
| | - Emilie C Snell-Rood
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Twin Cities, 1987 Upper Buford Circle, St. Paul, MN, 55108, USA
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6
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Clay NA, Herrmann MC, Evans-White MA, Entrekin SA, West C. Sodium as a subsidy in the spring: evidence for a phenology of sodium limitation. Oecologia 2023; 201:783-795. [PMID: 36853383 PMCID: PMC10038971 DOI: 10.1007/s00442-023-05336-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 02/10/2023] [Indexed: 03/01/2023]
Abstract
Understanding the factors that mediate carbon (C) cycling is increasingly important as anthropogenic activities and climate change alter ecosystems. Decomposition rates mediate C cycling and are in part regulated by sodium (Na) where Na is limiting up to some threshold after which Na becomes stressful and reduces decomposition rates (i.e., the Sodium Subsidy-Stress hypothesis). An overlooked pathway by which decomposers encounter increased salts like NaCl is through plants, which often take up Na in proportion to soil concentrations. Here we tested the hypothesis that Na addition through litter (detritus) and water and their interaction would impact detrital processing and leachate chemistry. Laboratory riparian soil mesocosms received either artificial litter (100% cellulose sponges) soaked in 0.05% NaCl (NaClL) or just H2O (H2OL: control) and half of each litter treatment received weekly additions of 150 ml of either 0.05% NaCl water (NaClW) or just H2O (H2OW: control). After 8 weeks decomposition was higher in NaCl addition treatments (both NaClL and NaClW and their combo) than controls (H2OL + H2OW) but reflected a unimodal relationship where the saltiest treatment (NaClL + NaClW) was only marginally higher than controls indicating a subsidy-stress response. Previous studies in this system found that Na addition in either water or litter decreased decomposition. However, differences may reflect a phenology of Na demand where Na-limitation increases in the spring (this study). These results indicate that our understanding of how Na impacts detrital processes, C cycling, and aquatic-terrestrial linkages necessitates incorporation of temporal dynamics.
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Affiliation(s)
- Natalie A Clay
- School of Biological Sciences, Louisiana Tech University, 1 Adams Blvd., Ruston, LA, 71272, USA.
| | - Maggie C Herrmann
- School of Biological Sciences, Louisiana Tech University, 1 Adams Blvd., Ruston, LA, 71272, USA
| | - Michelle A Evans-White
- Department of Biological Sciences, University of Arkansas, 525 Old Main, Fayetteville, AR, 72701, USA
| | - Sally A Entrekin
- Department of Entomology, Virginia Tech, 170 Drillfield Drive, Blacksburg, VA, 24061, USA
| | - Colton West
- School of Biological Sciences, Louisiana Tech University, 1 Adams Blvd., Ruston, LA, 71272, USA
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7
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Almeida RPS, Teresa FB, Camarota F, Izzo TJ, Silva RR, Andrade-Silva J, de Arruda FV. The role of morphological traits in predicting the functional ecology of arboreal and ground ants in the Cerrado-Amazon transition. Oecologia 2023; 201:199-212. [PMID: 36520222 DOI: 10.1007/s00442-022-05304-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 12/07/2022] [Indexed: 12/23/2022]
Abstract
There is often a vertical stratification of the vegetation in tropical forests, where each forest stratum has a unique set of environmental conditions, including marked differences in habitat heterogeneity, physical complexity, and microclimate. Additionally, many tropical forests are highly seasonal, and we need to consider the temporal variation in environmental conditions when assessing the functional aspects of their organisms. Here, we tested the hypothesis that vertical stratification and seasonality shape tropical ants' functional ecology and that there are differences in the functional trait diversity and composition between arboreal and ground-dwelling ant communities. We collected ants in the arboreal and ground strata in the rainy and dry seasons in six different areas, measuring seven morphological traits to characterize their functional ecology and diversity. Irrespective of the season, we found a distinct functional composition between arboreal and ground-dwelling ants and a higher functional richness on the ground. However, ground ants were more functionally redundant than arboreal ants. The differences in functional richness and redundancy between ant inhabiting strata and season could also be observed in the community-weighted mean traits: arboreal and ground ant traits can be distinguished in Weber's length, mandible length, eye length, and eye position on the head capsule. The differences in these functional traits are mainly related to the ants' feeding habits and the complexity of their foraging substrates. Overall, by providing the first systematic comparison of continuous traits between arboreal and ground-dwelling ants, our study opens new investigation paths, indicating important axes of functional diversification of tropical ants.
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Affiliation(s)
- Rony P S Almeida
- Laboratório de Morfologia e Ecologia Funcional de Formigas (AntMor), Museu Paraense Emílio Goeldi, Av. Perimetral, 1901, Terra Firme, Belém, PA, Brazil
| | - Fabrício B Teresa
- Universidade Estadual de Goiás, Campus Central, Anápolis, GO, Brazil
| | - Flávio Camarota
- Departamento de Genética, Ecologia e Evolução, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
| | - Thiago Junqueira Izzo
- Departamento de Botânica e Ecologia, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil
| | - Rogério R Silva
- Laboratório de Morfologia e Ecologia Funcional de Formigas (AntMor), Museu Paraense Emílio Goeldi, Av. Perimetral, 1901, Terra Firme, Belém, PA, Brazil
| | - Joudellys Andrade-Silva
- Laboratório de Morfologia e Ecologia Funcional de Formigas (AntMor), Museu Paraense Emílio Goeldi, Av. Perimetral, 1901, Terra Firme, Belém, PA, Brazil
| | - Filipe Viegas de Arruda
- Instituto de Pesquisa Ambiental da Amazônia (IPAM), Asa Norte Comércio Local Norte 211 BL B Sala 201-Asa Norte, Brasília, DF, 70863-520, Brazil
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8
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Finkelstein CJ, CaraDonna PJ, Gruver A, Welti EA, Kaspari M, Sanders NJ. Sodium-enriched floral nectar increases pollinator visitation rate and diversity. Biol Lett 2022; 18:20220016. [PMID: 35232272 PMCID: PMC8889166 DOI: 10.1098/rsbl.2022.0016] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Plants have evolved a variety of approaches to attract pollinators, including enriching their nectar with essential nutrients. Because sodium is an essential nutrient for pollinators, and sodium concentration in nectar can vary both within and among species, we explored whether experimentally enriching floral nectar with sodium in five plant species would influence pollinator visitation and diversity. We found that the number of visits by pollinators increased on plants with sodium-enriched nectar, regardless of plant species, relative to plants receiving control nectar. Similarly, the number of species visiting plants with sodium-enriched nectar was twice that of controls. Our findings suggest that sodium in floral nectar may play an important but unappreciated role in the ecology and evolution of plant-pollinator mutualisms.
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Affiliation(s)
- Carrie J. Finkelstein
- Environmental Program, Rubenstein School of Environment and Natural Resources, University of Vermont, Burlington, VT 05405, USA
| | - Paul J. CaraDonna
- Chicago Botanic Garden, 1000 Lake Cook Road, Glencoe, IL 60647, USA,Plant Biology and Conservation, Northwestern University, Evanston, IL 60208, USA,Rocky Mountain Biological Laboratory, P.O. Box 519, Crested Butte, CO 81224, USA
| | - Andrea Gruver
- Chicago Botanic Garden, 1000 Lake Cook Road, Glencoe, IL 60647, USA,Plant Biology and Conservation, Northwestern University, Evanston, IL 60208, USA
| | - Ellen A. R. Welti
- Conservation Ecology Center, Smithsonian Conservation Biology Institute, Front Royal, VA, USA
| | - Michael Kaspari
- Department of Biology, Geographical Ecology Group, University of Oklahoma, Norman, OK 73019, USA
| | - Nathan J. Sanders
- Rocky Mountain Biological Laboratory, P.O. Box 519, Crested Butte, CO 81224, USA,Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
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9
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Zhang Y, Jin Y, Xu J, He H, Tao Y, Yang Z, Bai Y. Effects of exogenous N and endogenous nutrients on alpine tundra litter decomposition in an area of high nitrogen deposition. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 805:150388. [PMID: 34818765 DOI: 10.1016/j.scitotenv.2021.150388] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 09/12/2021] [Accepted: 09/13/2021] [Indexed: 06/13/2023]
Abstract
The effects of N deposition on the C and N cycles via altered litter decomposition rates are an important aspect of global environmental change. The Changbai Mountain region experienced a high N deposition (2.7 g·m-2·year-1 in 2015) and corresponding expansion of Deyeuxia purpurea into the alpine tundra, resulting in changes in endogenous nutrients. However, the relative contributions of the N deposition and endogenous litter nutrients to litter decompositions remain unclear. Therefore, a 5-year N addition and 2-year litter decomposition experiments were conducted. Exogenous N reduced the remaining litter mass of Rhododendron aureum at the early stage (30-240 d) by promoting soluble sugar release, and increased it at the late stage (360-720 d) by suppressing lignin release and decreasing soil microbial community and enzyme activity. A higher proportion of D. purpurea litter (representing higher N, lower lignin, and C:N ratio) decreased remaining litter mass and increased net N release. Exogenous N decreased decomposition rate from 0.32 to 0.21 and net N release from 34% to 24%, whereas litter compositions increased decomposition rates from 0.32 to 0.69 and net litter N release from 34% to 69%. Endogenous litter nutrients directly explained 62% and 40% of the litter decomposition and net N release variables, respectively, whereas exogenous N indirectly explained 12% and 9%, respectively. Thus, we infer that the reductions in C and N storage following D. purpurea expansion may offset the increases of C and N storage under N deposition and the expansion of D. purpurea has a potential long-term negative impact on the ability of tundra plants to sequester C and N in the alpine tundra of the Changbai Mountains. These findings highlight how shifting plant expansion, through changes endogenous nutrients, can influence tundra litter decomposition and C and N storage responses to N deposition.
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Affiliation(s)
- Yingjie Zhang
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun 130024, China.
| | - Yinghua Jin
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun 130024, China.
| | - Jiawei Xu
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun 130024, China.
| | - Hongshi He
- School of Natural Resources, University of Missouri, Columbia, MO 65211, USA.
| | - Yan Tao
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun 130024, China.
| | - Zhipeng Yang
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun 130024, China.
| | - Yunyu Bai
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun 130024, China.
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10
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Evidence of sodium limitation in ants and termites in a Neotropical savanna. JOURNAL OF TROPICAL ECOLOGY 2022. [DOI: 10.1017/s0266467421000535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Abstract
Nutritional ecology of ropical ecosystems like Neotropical savannas, which are of high conservation concern, is understudied. Sodium is essential for heterotrophs but availability often falls short relative to plant consumer requirements. Savanna plant consumers like ants and termites should be sodium-limited due to high temperatures, nutrient-poor soils, and lack of oceanic sodium deposition. We tested the hypothesis that Neotropical savanna ants and termites are sodium-limited. Termites were tested by supplementing 0.25 m2 plots with H2O (control), 0.1%, 0.5%, or 1.0% NaCl and measuring termite presence and artificial substrate mass loss after 1 week. Ants were tested by collecting ants that recruited to H2O (control), 0.1%, 0.5%, and 1.0% NaCl and 1.0%, 10%, and 20% sugar baits on paired diurnal–nocturnal transects. Termites were 16 times more likely to occur on 1% NaCl than H2O plots and wood-feeding termites were most frequent. However, the decomposition rate did not differ among treatments. Ant bait use increased with increasing NaCl concentration and 1% NaCl usage was similar to sugar bait usage. Ants were 3.7 times more active nocturnally than diurnally, but contrary to predictions bait type (water, sugar or NaCl) usage did not differ between day and night. Together, these results provide strong evidence of sodium limitation in Neotropical savannas.
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11
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Kaspari M. The Invisible Hand of the Periodic Table: How Micronutrients Shape Ecology. ANNUAL REVIEW OF ECOLOGY, EVOLUTION, AND SYSTEMATICS 2021. [DOI: 10.1146/annurev-ecolsys-012021-090118] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Beyond the better-studied carbohydrates and the macronutrients nitrogen and phosphorus, a remaining 20 or so elements are essential for life and have distinct geographical distributions, making them of keen interest to ecologists. Here, I provide a framework for understanding how shortfalls in micronutrients like iodine, copper, and zinc can regulate individual fitness, abundance, and ecosystem function. With a special focus on sodium, I show how simple experiments manipulating biogeochemistry can reveal why many of the variables that ecologists study vary so dramatically from place to place. I conclude with a discussion of how the Anthropocene's changing temperature, precipitation, and atmospheric CO2 levels are contributing to nutrient dilution (decreases in the nutrient quality at the base of food webs).
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Affiliation(s)
- Michael Kaspari
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, Oklahoma 73019, USA
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12
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Clay NA, Siegert C, Tang JD, Little NS, Eckhardt LG, Riggins JJ. Termite Presence and Feeding on Loblolly Pine Wood Differs Among Four Root-Infecting Bluestain (ophiostomatoid) Fungal Species. ENVIRONMENTAL ENTOMOLOGY 2021; 50:1118-1126. [PMID: 34131713 DOI: 10.1093/ee/nvab052] [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: 01/28/2021] [Indexed: 06/12/2023]
Abstract
Bark beetles and root weevils can impact forests through tree death on landscape scales. Recently, subterranean termites have been linked to these beetles via the presence of bluestain fungi (Ascomycota: Ophiostomataceae), which are vectored to trees by beetles. However, only a small subset of bluestain species have been examined. Here, we tested whether termite-bluestain association patterns in the field reflect termite feeding preference in laboratory choice trials. We documented the presence of four bluestain fungi (Leptographium procerum (W.B. Kendr.), L. terebrantis (Barras & Perry), Grosmannia huntii (Rob.-Jeffr.), and G. alacris (T.A. Duong, Z.W. de Beer & M.J. Wingf.) in the roots of 2,350 loblolly pine trees in the southeastern United States and whether termites were present or absent on these roots and paired this with laboratory choice feeding trials. Termites were found 2.5-fold on tree roots with at least one bluestain fungus present than tree roots without bluestain fungi. Although termites in this study and others were associated with L. procerum, L. terebrantis, and marginally G. huntii, termites only showed preferential feeding on wood inoculated with G. huntii in laboratory trials. This suggests that increased termite presence on wood with bluestain fungi may be driven by factors other than increased wood palatability. Termites could thus disproportionately affect wood turnover rates for specific pools (e.g., bark beetle and root weevil attacked trees) and in some cases (e.g., G. huntii) accelerate wood decomposition. This study supports the growing evidence that the association between subterranean termites and bluestain fungi is spatially and taxonomically widespread.
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Affiliation(s)
- Natalie A Clay
- School of Biological Sciences, Louisiana Tech University, Ruston, LA, USA
| | - Courtney Siegert
- Department of Forestry, Forest and Wildlife Research Center, Mississippi State University, Mississippi State, MS, USA
| | - Juliet D Tang
- USDA Forest Service, Forest Products Laboratory, 201 Lincoln Green, Starkville, MS, USA
| | - Nathan S Little
- USDA-ARS, Southern Insect Management Research Unit, 141 Experiment Station Road, Stoneville, MS, USA
| | - Lori G Eckhardt
- School of Forestry and Wildlife Sciences, Auburn University, 602 Duncan Drive, Suite 3301, Auburn, AL, USA
| | - John J Riggins
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Box 9775, Mississippi State University, Mississippi State, MS, USA
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13
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Santiago‐Rosario LY, Harms KE, Elderd BD, Hart PB, Dassanayake M. No escape: The influence of substrate sodium on plant growth and tissue sodium responses. Ecol Evol 2021; 11:14231-14249. [PMID: 34707851 PMCID: PMC8525147 DOI: 10.1002/ece3.8138] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 08/16/2021] [Accepted: 09/01/2021] [Indexed: 01/21/2023] Open
Abstract
As an essential micronutrient for many organisms, sodium plays an important role in ecological and evolutionary dynamics. Although plants mediate trophic fluxes of sodium, from substrates to higher trophic levels, relatively little comparative research has been published about plant growth and sodium accumulation in response to variation in substrate sodium. Accordingly, we carried out a systematic review of plants' responses to variation in substrate sodium concentrations.We compared biomass and tissue-sodium accumulation among 107 cultivars or populations (67 species in 20 plant families), broadly expanding beyond the agricultural and model taxa for which several generalizations previously had been made. We hypothesized a priori response models for each population's growth and sodium accumulation as a function of increasing substrate NaCl and used Bayesian Information Criterion to choose the best model. Additionally, using a phylogenetic signal analysis, we tested for phylogenetic patterning of responses across taxa.The influence of substrate sodium on growth differed across taxa, with most populations experiencing detrimental effects at high concentrations. Irrespective of growth responses, tissue sodium concentrations for most taxa increased as sodium concentration in the substrate increased. We found no strong associations between the type of growth response and the type of sodium accumulation response across taxa. Although experiments often fail to test plants across a sufficiently broad range of substrate salinities, non-crop species tended toward higher sodium tolerance than domesticated species. Moreover, some phylogenetic conservatism was apparent, in that evolutionary history helped predict the distribution of total-plant growth responses across the phylogeny, but not sodium accumulation responses.Our study reveals that saltier plants in saltier soils proves to be a broadly general pattern for sodium across plant taxa. Regardless of growth responses, sodium accumulation mostly followed an increasing trend as substrate sodium levels increased.
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Affiliation(s)
| | - Kyle E. Harms
- Department of Biological SciencesLouisiana State UniversityBaton RougeLouisianaUSA
| | - Bret D. Elderd
- Department of Biological SciencesLouisiana State UniversityBaton RougeLouisianaUSA
| | - Pamela B. Hart
- Department of Biological SciencesLouisiana State UniversityBaton RougeLouisianaUSA
| | - Maheshi Dassanayake
- Department of Biological SciencesLouisiana State UniversityBaton RougeLouisianaUSA
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14
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Shephard AM, Mitchell TS, Snell-Rood EC. Monarch caterpillars are robust to combined exposure to the roadside micronutrients sodium and zinc. CONSERVATION PHYSIOLOGY 2021; 9:coab061. [PMID: 34386239 PMCID: PMC8354372 DOI: 10.1093/conphys/coab061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 06/08/2021] [Accepted: 07/21/2021] [Indexed: 06/13/2023]
Abstract
Human activities are increasing the environmental availability of micronutrients, including sodium and some essential metals. Micronutrients are often limiting in animal diets but may have negative effects when consumed in excess. Though prior research has documented how elevated exposure to individual micronutrients can impact organismal development and fitness, we know less about combined effects of multiple micronutrients. In the wild, monarch butterfly larvae (Danaus plexippus) commonly consume plants in roadside habitats that contain elevated levels of sodium (from road salt) and zinc (from vehicle wear-and-tear). We reared monarch caterpillars to adulthood to test individual and combined effects of dietary sodium and zinc on components of fitness, sodium-linked phenotypes (proxies for neural and flight muscle development) and concentrations of sodium and zinc in adult butterflies. Monarch survival was not impacted by elevated sodium or zinc individually or in combination. Yet, monarchs feeding on sodium-treated milkweed developed relatively larger eyes, consistent with a positive effect of sodium on neural development. Measurements of element concentrations in butterfly and plant tissue indicated that monarchs had higher zinc levels than those present in zinc-treated milkweed but lower sodium levels than those present in sodium-treated milkweed. Monarchs developing on sodium-treated milkweed also had prolonged development time, which might be a cost associated with developing extra neural tissue or investing in mechanisms to excrete excess dietary sodium during the larval stage. Our results indicate that sodium, more than zinc, is likely influencing phenotypic development and performance of insect pollinators in roadside habitats. Yet, in contrast to previous work, our experiment suggests that the highest levels of sodium found along roads are not always harmful for developing monarchs. Future work could consider how potentially stressful effects of micronutrients could be mitigated by increased macronutrient availability or how developmental factors such as migratory status might increase micronutrient requirements.
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Affiliation(s)
- Alexander M Shephard
- Corresponding author: Department of Ecology, Evolution, and Behavior, University of Minnesota, 1987 Upper Buford Circle, Saint Paul, MN 55108, USA.
| | - Timothy S Mitchell
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Twin Cities, Saint Paul, MN 55108, USA
| | - Emilie C Snell-Rood
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Twin Cities, Saint Paul, MN 55108, USA
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15
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Butler OM, Lewis T, Maunsell SC, Rezaei Rashti M, Elser JJ, Mackey B, Chen C. The stoichiometric signature of high‐frequency fire in forest floor food webs. ECOL MONOGR 2021. [DOI: 10.1002/ecm.1477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Orpheus M. Butler
- Australian Rivers Institute and Griffith School of Environment and Science Griffith University Nathan Queensland Australia
- School of Life and Environmental Sciences The University of Sydney Sydney New South Wales Australia
| | - Tom Lewis
- Department of Agriculture and Fisheries Agri‐Science Queensland University of the Sunshine Coast Maroochydore DC Queensland Australia
| | - Sarah C. Maunsell
- Department of Organismic and Evolutionary Biology Harvard University Boston Massachusetts USA
| | - Mehran Rezaei Rashti
- Australian Rivers Institute and Griffith School of Environment and Science Griffith University Nathan Queensland Australia
| | - James J. Elser
- Flathead Lake Biological Station University of Montana Polson Montana USA
| | - Brendan Mackey
- Griffith Climate Change Response Program Griffith University Gold Coast City Queensland Australia
| | - Chengrong Chen
- Australian Rivers Institute and Griffith School of Environment and Science Griffith University Nathan Queensland Australia
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16
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Welti EAR, Kaspari M. Sodium addition increases leaf herbivory and fungal damage across four grasslands. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13796] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Ellen A. R. Welti
- Geographical Ecology Group Department of Biology University of Oklahoma Norman OK USA
- Senckenberg Research Institute and Natural History Museum Frankfurt Gelnhausen Germany
| | - Michael Kaspari
- Geographical Ecology Group Department of Biology University of Oklahoma Norman OK USA
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17
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Crespo-Pérez V, Kazakou E, Roubik DW, Cárdenas RE. The importance of insects on land and in water: a tropical view. CURRENT OPINION IN INSECT SCIENCE 2020; 40:31-38. [PMID: 32563991 DOI: 10.1016/j.cois.2020.05.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 05/18/2020] [Accepted: 05/24/2020] [Indexed: 06/11/2023]
Abstract
Tropical insects are astonishingly diverse and abundant yet receive only marginal scientific attention. In natural tropical settings, insects are involved in regulating and supporting ecosystem services including seed dispersal, pollination, organic matter decomposition, nutrient cycling, herbivory, food webs and water quality, which in turn help fulfill UN Sustainable Development Goals (SDGs). Current and future global changes that affect insect diversity and distribution could disrupt key ecosystem services and impose important threats on ecosystems and human well-being. A significant increase in our knowledge of tropical insect roles in ecosystem processes is thus vital to ensure sustainable development on a rapidly changing planet.
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Affiliation(s)
- Verónica Crespo-Pérez
- Laboratorio de Entomología, Museo de Zoología QCAZ I, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Av. 12 de Octubre 1076 y Roca, Apartado: 17-01-2184 Quito, Ecuador.
| | - Elena Kazakou
- CEFE, Univ Montpellier, CNRS, EPHE, Institut Agro, IRD, Université Paul-Valéry Montpellier, Montpellier, France
| | - David W Roubik
- Smithsonian Tropical Research Institute, Balboa, Republic of Panama
| | - Rafael E Cárdenas
- Laboratorio de Entomología, Museo de Zoología QCAZ I, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Av. 12 de Octubre 1076 y Roca, Apartado: 17-01-2184 Quito, Ecuador.
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18
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Susser JR, Pelini SL, Weintraub MN. Can we reduce phosphorus runoff from agricultural fields by stimulating soil biota? JOURNAL OF ENVIRONMENTAL QUALITY 2020; 49:933-944. [PMID: 33016483 DOI: 10.1002/jeq2.20104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 04/21/2020] [Accepted: 05/13/2020] [Indexed: 06/11/2023]
Abstract
When fertilizer phosphorus (P) is applied to soils, the P can run off fields and cause harmful algal blooms. Due to its chemistry, much of the added P that does not run off can bind to soil particles and become inaccessible to plants. In natural systems, microbial and faunal decomposers can increase soil P accessibility to plants. We tested the hypothesis that this may also be true in agricultural systems, which could increase P application efficiency and reduce runoff potential. We stimulated soil fauna with sodium (Na+ ) and microbes with carbon (C) by adding corn (Zea mays L.) stover and Na+ solution to plots in conventionally managed corn fields in northwestern Ohio. Stover addition increased microbial biomass by 65 ± 12% and respiration by 400-700%. Application of stover with Na+ increased soil detritivore fauna abundance by 51 ± 20% and likely did not affect the other invertebrate guilds. However, soil biological activity was low compared with natural systems in all treatments and was not correlated with instantaneous measures of P accessibility, though cumulative P accessibility over the course of the growing season was correlated with microbial phosphatase activity (slope = 1.01, p < .01) and respiration (slope = 0.42, p = .02). Therefore, in agricultural systems, treatments to stimulate decomposers already in those systems may be ineffective at increasing soil P accessibility in the short term, but in the long term, higher microbial activities can be associated with higher soil P accessibility.
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Affiliation(s)
- Jessica R Susser
- Dep. of Environmental Sciences, Univ. of Toledo, 2801 W. Bancroft St., Toledo, OH, 43606, USA
| | - Shannon L Pelini
- Dep. of Biological Sciences, Bowling Green State Univ., 217 Life Sciences Building, Bowling Green, OH, 43403, USA
| | - Michael N Weintraub
- Dep. of Environmental Sciences, Univ. of Toledo, 2801 W. Bancroft St., Toledo, OH, 43606, USA
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19
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Kaspari M. The seventh macronutrient: how sodium shortfall ramifies through populations, food webs and ecosystems. Ecol Lett 2020; 23:1153-1168. [PMID: 32380580 DOI: 10.1111/ele.13517] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 01/28/2020] [Accepted: 03/17/2020] [Indexed: 11/27/2022]
Abstract
Of the 25 elements required to build most organisms, sodium has a unique set of characteristics that ramify through terrestrial ecology. In plants, sodium is found in low concentrations and has little metabolic function; in plant consumers, particularly animals, sodium is essential to running costly Na-K ATPases. Here I synthesise a diverse literature from physiology, agronomy and ecology, towards identifying sodium's place as the '7th macronutrient', one whose shortfall targets two trophic levels - herbivores and detritivores. I propose that sodium also plays a central, though unheralded role in herbivore digestion, via its importance to maintaining microbiomes and denaturing tannins. I highlight how sodium availability is a key determinant of consumer abundance and the geography of herbivory and detritivory. And I propose a re-appraisal of the assumption that, because sodium is metabolically unimportant to most plants, it is of little use. Instead, I suggest that sodium's critical role in limiting herbivore performance makes it a commodity used by plants to manipulate their herbivores and mutualists, and by consumers like bison and elephants to generate grazing lawns: dependable sources of sodium.
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Affiliation(s)
- Michael Kaspari
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, OK, USA
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20
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Sarker TC, Maisto G, De Marco A, Memoli V, Panico SC, Motti R, Idbella M, Incerti G, Mazzoleni S, Bonanomi G. Species‐specific root proliferation of tree seedlings in tropical litter: do nutrients matter? OIKOS 2020. [DOI: 10.1111/oik.06786] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Tushar C. Sarker
- Dept of Agricultural Science, Univ. of Naples Federico II via Università 100 IT‐80055 Portici (NA) Italy
- School of Environmental and Resource Sciences, Zhejiang A&F Univ. Lin'an PR China
| | - Giulia Maisto
- Dept of Biology, Univ. of Naples Federico II Napoli Italy
| | - Anna De Marco
- Dept of Biology, Univ. of Naples Federico II Napoli Italy
| | - Valeria Memoli
- Dept of Biology, Univ. of Naples Federico II Napoli Italy
| | | | - Riccardo Motti
- Dept of Agricultural Science, Univ. of Naples Federico II via Università 100 IT‐80055 Portici (NA) Italy
| | - Mohamed Idbella
- Dept of Agricultural Science, Univ. of Naples Federico II via Università 100 IT‐80055 Portici (NA) Italy
| | - Guido Incerti
- Di4A, Dept of Agri‐Food, Animal and Environmental Sciences, Univ. of Udine Udine Italy
| | - Stefano Mazzoleni
- Dept of Agricultural Science, Univ. of Naples Federico II via Università 100 IT‐80055 Portici (NA) Italy
| | - Giuliano Bonanomi
- Dept of Agricultural Science, Univ. of Naples Federico II via Università 100 IT‐80055 Portici (NA) Italy
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21
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Sayer EJ, Rodtassana C, Sheldrake M, Bréchet LM, Ashford OS, Lopez-Sangil L, Kerdraon-Byrne D, Castro B, Turner BL, Wright SJ, Tanner EV. Revisiting nutrient cycling by litterfall—Insights from 15 years of litter manipulation in old-growth lowland tropical forest. ADV ECOL RES 2020. [DOI: 10.1016/bs.aecr.2020.01.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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22
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Camenzind T, Scheu S, Rillig MC. Expanding the toolbox of nutrient limitation studies: A novel method of soil microbial in‐growth bags to evaluate nutrient demands in tropical forests. Funct Ecol 2019. [DOI: 10.1111/1365-2435.13352] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Tessa Camenzind
- Institute of Biology, Plant Ecology Freie Universität Berlin Berlin Germany
- Berlin‐Brandenburg Institute of Advanced Biodiversity Research (BBIB) Berlin Germany
| | - Stefan Scheu
- J.F. Blumenbach Institute of Zoology and Anthropology, Animal Ecology University of Göttingen Göttingen Germany
- Centre of Biodiversity and Sustainable Land Use University of Göttingen Göttingen Germany
| | - Matthias C. Rillig
- Institute of Biology, Plant Ecology Freie Universität Berlin Berlin Germany
- Berlin‐Brandenburg Institute of Advanced Biodiversity Research (BBIB) Berlin Germany
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23
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Reynolds V, Pascual-Garrido A, Lloyd AW, Lyons P, Hobaiter C. Possible mineral contributions to the diet and health of wild chimpanzees in three East African forests. Am J Primatol 2019; 81:e22978. [PMID: 31090097 DOI: 10.1002/ajp.22978] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Revised: 02/27/2019] [Accepted: 03/27/2019] [Indexed: 11/11/2022]
Abstract
We present new data on the ingestion of minerals from termite mound soil by East African chimpanzees (Pan troglodytes schweinfurthii) living in the Budongo Forest Reserve, Uganda, the Gombe National Park and the Mahale Mountains National Park, Tanzania. Termite mound soil is here shown to be a rich source of minerals, containing high concentrations of iron and aluminum. Termite mound soil is not, however, a source of sodium. The concentrations of iron and aluminum are the highest yet found in any of the mineral sources consumed. Levels of manganese and copper, though not so high as for iron and aluminum, are also higher than in other dietary sources. We focus on the contribution of termite mound soil to other known sources of mineral elements consumed by these apes, and compare the mineral content of termite soil with that of control forest soil, decaying wood, clay, and the normal plant-based chimpanzee diet at Budongo. Samples obtained from Mahale Mountains National Park and Gombe National Park, both in Tanzania, show similar mineral distribution across sources. We suggest three distinct but related mechanisms by which minerals may come to be concentrated in the above-mentioned sources, serving as potentially important sources of essential minerals in the chimpanzee diet.
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Affiliation(s)
- Vernon Reynolds
- School of Anthropology and Museum Ethnography, Oxford University, Oxford, United Kingdom.,Budongo Conservation Field Station, Masindi, Uganda
| | - Alejandra Pascual-Garrido
- Primate Models for Behavioural Evolution Lab, Institute of Cognitive and Evolutionary Anthropology, School of Anthropology and Museum Ethnography, University of Oxford, Oxford, United Kingdom.,School of Archaeology, University of Oxford, United Kingdom
| | - Andrew W Lloyd
- School of Environment & Technology, University of Brighton, Brighton, United Kingdom
| | - Peter Lyons
- School of Environment & Technology, University of Brighton, Brighton, United Kingdom
| | - Catherine Hobaiter
- Budongo Conservation Field Station, Masindi, Uganda.,School of Psychology and Neuroscience, University of St Andrews, St Marys College, South Street, St Andrews, Scotland
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24
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Welti EAR, Sanders NJ, de Beurs KM, Kaspari M. A distributed experiment demonstrates widespread sodium limitation in grassland food webs. Ecology 2019; 100:e02600. [PMID: 30726560 DOI: 10.1002/ecy.2600] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 11/28/2018] [Accepted: 12/20/2018] [Indexed: 01/07/2023]
Abstract
Sodium (Na) has a unique role in food webs as a nutrient primarily limiting for plant consumers, but not other trophic levels. Environmental Na levels vary with proximity to coasts, local geomorphology, climate, and with anthropogenic inputs (e.g., road salt). We tested two key predictions across 54 grasslands in North America: Na shortfall commonly limits herbivore abundance, and the magnitude of this limitation varies inversely with environmental Na supplies. We tested them with a distributed pulse experiment and evaluated the relative importance of Na limitation to other classic drivers of climate, macronutrient levels, and plant productivity. Herbivore abundance increased by 45% with Na addition. Moreover, the magnitude of increase on Na addition plots decreased with increasing levels of plant Na, indicating Na satiation at sites with high Na concentrations in plant tissue. Our results demonstrate that invertebrate primary consumers are often Na limited and track local Na availability, with implications for the geography of invertebrate abundance and herbivory.
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Affiliation(s)
- Ellen A R Welti
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Nathan J Sanders
- The Environmental Program, Rubenstein School of Environment and Natural Resources, University of Vermont, Burlington, Vermont, 05405, USA
| | - Kirsten M de Beurs
- Department of Geography and Environmental Sustainability, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Michael Kaspari
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA
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25
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Ashton LA, Griffiths HM, Parr CL, Evans TA, Didham RK, Hasan F, Teh YA, Tin HS, Vairappan CS, Eggleton P. Termites mitigate the effects of drought in tropical rainforest. Science 2019; 363:174-177. [DOI: 10.1126/science.aau9565] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 12/06/2018] [Indexed: 12/31/2022]
Abstract
Termites perform key ecological functions in tropical ecosystems, are strongly affected by variation in rainfall, and respond negatively to habitat disturbance. However, it is not known how the projected increase in frequency and severity of droughts in tropical rainforests will alter termite communities and the maintenance of ecosystem processes. Using a large-scale termite suppression experiment, we found that termite activity and abundance increased during drought in a Bornean forest. This increase resulted in accelerated litter decomposition, elevated soil moisture, greater soil nutrient heterogeneity, and higher seedling survival rates during the extreme El Niño drought of 2015–2016. Our work shows how an invertebrate group enhances ecosystem resistance to drought, providing evidence that the dual stressors of climate change and anthropogenic shifts in biotic communities will have various negative consequences for the maintenance of rainforest ecosystems.
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26
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Entrekin SA, Clay NA, Mogilevski A, Howard-Parker B, Evans-White MA. Multiple riparian-stream connections are predicted to change in response to salinization. Philos Trans R Soc Lond B Biol Sci 2018; 374:20180042. [PMID: 30509922 PMCID: PMC6283969 DOI: 10.1098/rstb.2018.0042] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/10/2018] [Indexed: 12/20/2022] Open
Abstract
Secondary freshwater salinization, a common anthropogenic alteration, has detrimental, lethal and sub-lethal effects on aquatic biota. Ions from secondary salinization can become toxic to terrestrial and aquatic organisms when exposed to salinized runoff that causes periodic high-concentration pulses. Gradual, low-level (less than 1000 ppm salinity) increases in salt concentrations are also commonly documented in regions with urbanization, agriculture, drilling and mining. Despite widespread low-level salt increases, little is known about the biological and ecological consequences in coupled riparian-stream systems. Recent research indicates lethal and even sub-lethal levels of ions can subsidize or stress microbial decomposer and macroinvertebrate detritivores that could lead to alterations of three riparian-stream pathways: (i) salinized runoff that changes microbial decomposer and macroinvertebrate detritivore and algae performance leading to changes in composition and processing of detrital pools; (ii) riparian plant salt uptake and altered litter chemistry, and litterfall for riparian and aquatic detritivores and their subsequent enrichment, stimulating decomposition rates and production of dissolved and fine organic matter; and (iii) salt consumption in salinized soils could increase riparian detritivore growth, decomposition and dissolved organic matter production. Subsidy-stress and reciprocal flows in coupled riparian-stream connections provide frameworks to identify the extent and magnitude of changes in detrital processing from salinization.This article is part of the theme issue 'Salt in freshwaters: causes, ecological consequences and future prospects'.
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Affiliation(s)
- Sally A Entrekin
- Department of Biology, University of Central Arkansas, Conway, AR 72035, USA
- Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Natalie A Clay
- School of Biological Sciences, Louisiana Tech University, Ruston, LA 71272, USA
| | | | - Brooke Howard-Parker
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA
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27
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Prather RM, Roeder KA, Sanders NJ, Kaspari M. Using metabolic and thermal ecology to predict temperature dependent ecosystem activity: a test with prairie ants. Ecology 2018; 99:2113-2121. [DOI: 10.1002/ecy.2445] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 05/22/2018] [Accepted: 06/18/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Rebecca M. Prather
- Department of Biology Graduate Program in Ecology and Evolutionary Biology University of Oklahoma Norman Oklahoma 73019 USA
| | - Karl A. Roeder
- Department of Biology Graduate Program in Ecology and Evolutionary Biology University of Oklahoma Norman Oklahoma 73019 USA
| | - Nathan J. Sanders
- Rubenstein School of Environment and Natural Resources University of Vermont Burlington Vermont 05405 USA
| | - Michael Kaspari
- Department of Biology Graduate Program in Ecology and Evolutionary Biology University of Oklahoma Norman Oklahoma 73019 USA
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28
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Prather CM, Laws AN, Cuellar JF, Reihart RW, Gawkins KM, Pennings SC. Seeking salt: herbivorous prairie insects can be co-limited by macronutrients and sodium. Ecol Lett 2018; 21:1467-1476. [PMID: 30039540 DOI: 10.1111/ele.13127] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 05/23/2018] [Accepted: 06/08/2018] [Indexed: 11/28/2022]
Abstract
The canonical factors typically thought to determine herbivore community structure often explain only a small fraction of the variation in herbivore abundance and diversity. We tested how macronutrients and relatively understudied micronutrients interacted to influence the structure of insect herbivore (orthopteran) communities. We conducted a factorial fertilisation experiment manipulating macronutrients (N and P, added together) and micronutrients (Ca, Na and K) in large plots (30 × 30 m2 ) in a Texas coastal prairie. Although no single or combination of micronutrients affected herbivore communities in the absence of additional macronutrients, macronutrients and sodium added together increased herbivore abundance by 60%, richness by 15% and diversity by 20%. These results represent the first large-scale manipulation of single micronutrients and macronutrients in concert, and revealed an herbivore community co-limited by macronutrients and Na. Our work supports an emerging paradigm that Na may be important in limiting herbivore communities.
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Affiliation(s)
- Chelse M Prather
- Department of Biology, Radford University, Radford, VA, 46556, USA.,Department of Biology, University of Dayton, Dayton, OH, 45469, USA
| | - Angela N Laws
- Department of Biology and Biochemistry, University of Houston, Houston, TX, 77204, USA.,The Xerces Society, Sacramento, CA, 95814, USA
| | - Juan F Cuellar
- Department of Biology and Biochemistry, University of Houston, Houston, TX, 77204, USA
| | - Ryan W Reihart
- Department of Biology, University of Dayton, Dayton, OH, 45469, USA
| | | | - Steven C Pennings
- Department of Biology and Biochemistry, University of Houston, Houston, TX, 77204, USA
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Camenzind T, Lehmberg J, Weimershaus P, Álvarez-Garrido L, Andrade Linares DR, Súarez JP, Rillig MC. Do fungi need salt licks? No evidence for fungal contribution to the Sodium Ecosystem Respiration Hypothesis based on lab and field experiments in Southern Ecuador. FUNGAL ECOL 2018. [DOI: 10.1016/j.funeco.2017.11.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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30
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Camenzind T, Hättenschwiler S, Treseder KK, Lehmann A, Rillig MC. Nutrient limitation of soil microbial processes in tropical forests. ECOL MONOGR 2017. [DOI: 10.1002/ecm.1279] [Citation(s) in RCA: 174] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Tessa Camenzind
- Institute of Biology; Freie Universität Berlin; Altensteinstr. 6 14195 Berlin Germany
- Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB); 14195 Berlin Germany
| | - 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
| | - Kathleen K. Treseder
- School of Biological Sciences; University of California; Irvine California 92697 USA
| | - Anika Lehmann
- Institute of Biology; Freie Universität Berlin; Altensteinstr. 6 14195 Berlin Germany
- Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB); 14195 Berlin Germany
| | - Matthias C. Rillig
- Institute of Biology; Freie Universität Berlin; Altensteinstr. 6 14195 Berlin Germany
- Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB); 14195 Berlin Germany
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31
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Clay NA, Lehrter RJ, Kaspari M. Towards a geography of omnivory: Omnivores increase carnivory when sodium is limiting. J Anim Ecol 2017; 86:1523-1531. [DOI: 10.1111/1365-2656.12754] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 08/24/2017] [Indexed: 11/26/2022]
Affiliation(s)
| | | | - Michael Kaspari
- Department of Biology University of Oklahoma Norman OK USA
- Smithsonian Tropical Research Institute Balboa Panama
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32
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Brightsmith DJ, Cáceres A. Parrots consume sodium-rich palms in the sodium-deprived landscape of the Western Amazon Basin. Biotropica 2017. [DOI: 10.1111/btp.12479] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Donald J. Brightsmith
- Department of Veterinary Pathobiology; Schubot Exotic Bird Health Center; Texas A&M University; College Station TX 77843-4467 U.S.A
| | - Aimy Cáceres
- Escuela de Ingeniería Ambiental; Facultad de Ingeniería; Universidad San Ignacio de Loyola; Av. La Fontana 550 La Molina Lima Perú
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33
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Jochum M, Barnes AD, Ott D, Lang B, Klarner B, Farajallah A, Scheu S, Brose U. Decreasing Stoichiometric Resource Quality Drives Compensatory Feeding across Trophic Levels in Tropical Litter Invertebrate Communities. Am Nat 2017; 190:131-143. [DOI: 10.1086/691790] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Scharnagl K, Scharnagl A, von Wettberg E. Nature's potato chip: The role of salty fungi in a changing world. AMERICAN JOURNAL OF BOTANY 2017; 104:641-644. [PMID: 28456762 DOI: 10.3732/ajb.1700034] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 03/28/2017] [Indexed: 06/07/2023]
Affiliation(s)
- Klara Scharnagl
- Department of Plant Biology, 612 Wilson Road, Michigan State University, East Lansing, Michigan 48824 USA
| | - Anna Scharnagl
- Division of Biological Sciences, 105 Tucker Hall, University of Missouri, Columbia, Missouri 65211 USA
| | - Eric von Wettberg
- Department of Biological Sciences and International Center for Tropical Botany, Florida International University, Miami, Florida 33199 USA
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35
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Simpson SJ, Raubenheimer D. Nutritional Physiology: Sex Elicits a Taste for Salt in Drosophila. Curr Biol 2016; 25:R980-2. [PMID: 26485369 DOI: 10.1016/j.cub.2015.09.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Increased salt intake has been found to boost egg production in Drosophila. Females develop a specific appetite for salt following mating. This is not triggered by demand for sodium from developing eggs, but by release of a Sex Peptide into the female's reproductive tract by the male during mating.
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Affiliation(s)
- Stephen J Simpson
- Charles Perkins Centre, the University of Sydney, Sydney, New South Wales, Australia; School of Biological Sciences, the University of Sydney, Sydney, New South Wales, Australia.
| | - David Raubenheimer
- Charles Perkins Centre, the University of Sydney, Sydney, New South Wales, Australia; School of Biological Sciences, the University of Sydney, Sydney, New South Wales, Australia; The Faculty of Veterinary Science, the University of Sydney, Sydney, New South Wales, Australia
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36
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Kaspari M, Powers JS. Biogeochemistry and Geographical Ecology: Embracing All Twenty-Five Elements Required to Build Organisms. Am Nat 2016; 188 Suppl 1:S62-73. [PMID: 27513911 DOI: 10.1086/687576] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Biogeochemistry is a key but relatively neglected part of the abiotic template that underlies ecology. The template has a geography, one that is increasingly being rearranged in this era of global change. Justus von Liebig's law of the minimum has played a useful role in focusing attention on biogeochemical regulation of populations, but given that ∼25+ elements are required to build organisms and that these organisms use and deplete nutrients in aggregates of communities and ecosystems, we make the case that it is time to move on. We review available models that suggest the many different mechanisms that give rise to multiple elements, or colimitation. We then review recent empirical data that show that rates of decomposition and primary productivity may be limited by multiple elements. In that light, given the tropics' high species diversity and generally more weathered soils, we predict that colimitation at community and ecosystem scales is more prevalent closer to the equator. We conclude with suggestions for how to move forward with experimental studies of colimitation.
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Abstract
Large herbivores and carnivores (the megafauna) have been in a state of decline and extinction since the Late Pleistocene, both on land and more recently in the oceans. Much has been written on the timing and causes of these declines, but only recently has scientific attention focused on the consequences of these declines for ecosystem function. Here, we review progress in our understanding of how megafauna affect ecosystem physical and trophic structure, species composition, biogeochemistry, and climate, drawing on special features of PNAS and Ecography that have been published as a result of an international workshop on this topic held in Oxford in 2014. Insights emerging from this work have consequences for our understanding of changes in biosphere function since the Late Pleistocene and of the functioning of contemporary ecosystems, as well as offering a rationale and framework for scientifically informed restoration of megafaunal function where possible and appropriate.
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38
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Elemental concentrations in the frass of saproxylic insects suggest a role in micronutrient cycling. Ecosphere 2016. [DOI: 10.1002/ecs2.1300] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
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39
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Dambros CS, Morais JW, Vasconcellos A, Souza JLP, Franklin E, Gotelli NJ. Association of Ant Predators and Edaphic Conditions with Termite Diversity in an Amazonian Rain Forest. Biotropica 2016. [DOI: 10.1111/btp.12270] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
| | - José W. Morais
- Coordenação de Biodiversidade National Institute of Amazonian Research CP 2223 69067‐375 Manaus AM Brazil
| | - Alexandre Vasconcellos
- Departamento de Sistemática e Ecologia Laboratório de Termitologia Universidade Federal da Paraíba CCEN 58051‐900 João Pessoa PB Brazil
| | - Jorge L. P. Souza
- Coordenação de Biodiversidade National Institute of Amazonian Research CP 2223 69067‐375 Manaus AM Brazil
| | - Elizabeth Franklin
- Coordenação de Biodiversidade National Institute of Amazonian Research CP 2223 69067‐375 Manaus AM Brazil
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40
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Geographic, environmental and biotic sources of variation in the nutrient relations of tropical montane forests. JOURNAL OF TROPICAL ECOLOGY 2015. [DOI: 10.1017/s0266467415000619] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract:Tropical montane forests (TMF) are associated with a widely observed suite of characteristics encompassing forest structure, plant traits and biogeochemistry. With respect to nutrient relations, montane forests are characterized by slow decomposition of organic matter, high investment in below-ground biomass and poor litter quality, relative to tropical lowland forests. However, within TMF there is considerable variation in substrate age, parent material, disturbance and species composition. Here we emphasize that many TMFs are likely to be co-limited by multiple nutrients, and that feedback among soil properties, species traits, microbial communities and environmental conditions drive forest productivity and soil carbon storage. To date, studies of the biogeochemistry of montane forests have been restricted to a few, mostly neotropical, sites and focused mainly on trees while ignoring mycorrhizas, epiphytes and microbial community structure. Incorporating the geographic, environmental and biotic variability in TMF will lead to a greater recognition of plant–soil feedbacks that are critical to understanding constraints on productivity, both under present conditions and under future climate, nitrogen-deposition and land-use scenarios.
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41
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Cease AJ, Fay M, Elser JJ, Harrison JF. Dietary phosphate affects food selection, post-ingestive phosphorus fate, and performance of a polyphagous herbivore. J Exp Biol 2015; 219:64-72. [PMID: 26567345 DOI: 10.1242/jeb.126847] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 10/27/2015] [Indexed: 11/20/2022]
Abstract
Comparisons of the carbon, nitrogen and phosphorus (P) content of plants and insect herbivores suggests that P limitation and herbivore foraging to balance P intake could be common. However, the lack of synthetic diets for testing the effects of lower ranges of dietary P has been a major impediment to experimental assessment of the ecological importance of, and physiological responses to, P limitation for terrestrial herbivores. We manipulated dietary P content (%P) over its observed range in terrestrial foliage using artificial diets containing near-optimal content of other nutrients for the grasshopper Schistocerca americana. Over much of the ecologically relevant range, when consuming single diets over a lifetime, higher P stimulated growth rates and increased survival, with an optimal dietary %P of 0.25-0.50% when measured throughout development. Excessive dietary P (1%) reduced growth and survival. However, with only short-term (3 day) confinement to single diets, dietary P had no effect on food consumption or growth rates. During these short exposures, fifth (but not third) instar hoppers increased the proportion of P excreted relative to P assimilated as dietary P increased. Target experiments demonstrated that, when given a choice, grasshoppers select among foods to attain a P intake target of 0.6%. These data suggest that P limitation could be common for terrestrial insect herbivores and that they can exhibit ingestive and post-ingestive mechanisms to attain sufficient but not excessive P.
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Affiliation(s)
- Arianne J Cease
- School of Sustainability, Arizona State University, Tempe, AZ 85287, USA
| | - Michelle Fay
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA Orange Coast College, Costa Mesa, CA 92626, USA
| | - James J Elser
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Jon F Harrison
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
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42
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Postmating Circuitry Modulates Salt Taste Processing to Increase Reproductive Output in Drosophila. Curr Biol 2015; 25:2621-30. [PMID: 26412135 DOI: 10.1016/j.cub.2015.08.043] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 08/13/2015] [Accepted: 08/19/2015] [Indexed: 11/21/2022]
Abstract
To optimize survival and reproduction, animals must match their nutrient intake to their current needs. Reproduction profoundly changes nutritional requirements, with many species showing an appetite for sodium during reproductive periods. How this internal state modifies neuronal information processing to ensure homeostasis is not understood. Here, we show that dietary sodium levels positively affect reproductive output in Drosophila melanogaster; to satisfy this requirement, females develop a strong, specific appetite for sodium following mating. We show that mating modulates gustatory processing to increase the probability of initiating feeding on salt. This postmating effect is not due to salt depletion by egg production, since abolishing egg production leaves the sodium appetite intact. Rather, the salt appetite is induced need-independently by male-derived Sex Peptide acting on the Sex Peptide Receptor in female reproductive tract neurons. We further demonstrate that postmating appetites for both salt and yeast are driven by the resultant silencing of downstream SAG neurons. Surprisingly, unlike the postmating yeast appetite, the salt appetite does not require octopamine, suggesting a divergence in the postmating circuitry. These findings demonstrate that the postmating circuit supports reproduction by increasing the palatability of specific nutrients. Such a feedforward regulation of sensory processing may represent a common mechanism through which reproductive state-sensitive circuits modify complex behaviors across species.
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43
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Cárdenas RE, Hättenschwiler S, Valencia R, Argoti A, Dangles O. Plant herbivory responses through changes in leaf quality have no effect on subsequent leaf-litter decomposition in a neotropical rain forest tree community. THE NEW PHYTOLOGIST 2015; 207:817-829. [PMID: 25771942 DOI: 10.1111/nph.13368] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 02/12/2015] [Indexed: 06/04/2023]
Abstract
It is commonly accepted that plant responses to foliar herbivory (e.g. plant defenses) can influence subsequent leaf-litter decomposability in soil. While several studies have assessed the herbivory-decomposability relationship among different plant species, experimental tests at the intra-specific level are rare, although critical for a mechanistic understanding of how herbivores affect decomposition and its consequences at the ecosystem scale. Using 17 tree species from the Yasuní National Park, Ecuadorian Amazonia, and applying three different herbivore damage treatments, we experimentally tested whether the plant intra-specific responses to herbivory, through changes in leaf quality, affect subsequent leaf-litter decomposition in soil. We found no effects of herbivore damage on the subsequent decomposition of leaf litter within any of the species tested. Our results suggest that leaf traits affecting herbivory are different from those influencing decomposition. Herbivore damage showed much higher intra-specific than inter-specific variability, while we observed the opposite for decomposition. Our findings support the idea that interactions between consumers and their resources are controlled by different factors for the green and the brown food-webs in tropical forests, where herbivory may not necessarily generate any direct positive or negative feedbacks for nutrient cycling.
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Affiliation(s)
- Rafael E Cárdenas
- Museo de Zoología QCAZ, Laboratorio de Entomología, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Av. 12 de octubre 1076 y Roca, Apdo. 17-01-2184, Quito, Ecuador
- Institut de Recherche pour le Développement (IRD), UR 072, LEGS-CNRS, UPR 9034, CNRS, Gif-sur-Yvette, Cedex, 91198, France
- Université Paris-Sud 11, Orsay, Cedex, 91405, France
| | - Stephan Hättenschwiler
- Centre d'Écologie Fonctionnelle et Évolutive (CEFE UMR 5175 - Université de Montpellier - Université Paul-Valéry Montpellier - EPHE), 1919 route de Mende, 34293, Montpellier Cedex 5, France
| | - Renato Valencia
- Herbario QCA, Laboratorio de Ecología de Plantas, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Av. 12 de octubre 1076 y Roca, Apdo. 17-01-2184, Quito, Ecuador
| | - Adriana Argoti
- Museo de Zoología QCAZ, Laboratorio de Entomología, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Av. 12 de octubre 1076 y Roca, Apdo. 17-01-2184, Quito, Ecuador
| | - Olivier Dangles
- Institut de Recherche pour le Développement (IRD), UR 072, LEGS-CNRS, UPR 9034, CNRS, Gif-sur-Yvette, Cedex, 91198, France
- Université Paris-Sud 11, Orsay, Cedex, 91405, France
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44
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Hobbie SE. Plant species effects on nutrient cycling: revisiting litter feedbacks. Trends Ecol Evol 2015; 30:357-63. [DOI: 10.1016/j.tree.2015.03.015] [Citation(s) in RCA: 296] [Impact Index Per Article: 32.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 03/20/2015] [Accepted: 03/24/2015] [Indexed: 11/28/2022]
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45
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Clay NA, Donoso DA, Kaspari M. Urine as an important source of sodium increases decomposition in an inland but not coastal tropical forest. Oecologia 2014; 177:571-9. [PMID: 25519175 DOI: 10.1007/s00442-014-3183-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 12/04/2014] [Indexed: 11/29/2022]
Abstract
Nutrient pulses can profoundly impact ecosystem processes and urine is a frequently deposited source of N and K, and Na. Na is unimportant to plants, but its addition can increase decomposition and change invertebrate community structure in Na-poor tropical forests. Here we used synthetic urine to separate the effects of Na from urine's other nutrients and contrasted their roles in promoting decomposition and detritivore recruitment in both a Na-poor inland Ecuadorian and Na-rich coastal Panamanian tropical forest. After 2 days, invertebrate communities did not vary among +Na, H2O, Urine+Na, and Urine-Na treatments. But after 2 weeks, Ecuador wood, but not cellulose, decomposition was twofold higher on Urine+Na and +Na plots compared to H2O and Urine-Na plots accompanied by >20-fold increases in termite abundance on these plots. Panama, in contrast, showed no effect of Na on decomposition. In both forests, plots fertilized with urine had nearly twofold decrease in detritivores after 2 weeks that was likely a shock effect from ammonification. Moreover, the non-Na nutrients in urine did not enhance decomposition at this time scale. On control plots, Panama had higher decomposition rates for both cellulose and wood than Ecuador, but the addition of Na in Ecuador alleviated these differences. These results support the hypothesis that in Na-poor tropical forests, urine can enhance wood decomposition and generate an important source of heterogeneity in the abundance and activity of brown food webs.
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Affiliation(s)
- Natalie A Clay
- Department of Biology, University of Oklahoma, 730 Van Vleet Oval, Norman, OK, 73019, USA,
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46
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Road salt offers insights into the connections between diet and neural development. Proc Natl Acad Sci U S A 2014; 111:10033-4. [PMID: 24965365 DOI: 10.1073/pnas.1408653111] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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47
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Warne RW. The Micro and Macro of Nutrients across Biological Scales. Integr Comp Biol 2014; 54:864-72. [DOI: 10.1093/icb/icu071] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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