1
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Kaspari M, Weiser MD, Siler CD, Marshall KE, Smith SN, Stroh KM, de Beurs KM. Capacity and establishment rules govern the number of nonnative species in communities of ground-dwelling invertebrates. Ecol Evol 2024; 14:e10856. [PMID: 38487748 PMCID: PMC10937486 DOI: 10.1002/ece3.10856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 01/05/2024] [Accepted: 01/14/2024] [Indexed: 03/17/2024] Open
Abstract
Nonnative species are a key agent of global change. However, nonnative invertebrates remain understudied at the community scales where they are most likely to drive local extirpations. We use the North American NEON pitfall trapping network to document the number of nonnative species from 51 invertebrate communities, testing four classes of drivers. We sequenced samples using the eDNA from the sample's storage ethanol. We used AICc informed regression to evaluate how native species richness, productivity, habitat, temperature, and human population density and vehicular traffic account for continent-wide variation in the number of nonnative species in a local community. The percentage of nonnatives varied 3-fold among habitat types and over 10-fold (0%-14%) overall. We found evidence for two types of constraints on nonnative diversity. Consistent with Capacity rules (i.e., how the number of niches and individuals reflect the number of species an ecosystem can support) nonnatives increased with existing native species richness and ecosystem productivity. Consistent with Establishment Rules (i.e., how the dispersal rate of nonnative propagules and the number of open sites limits nonnative species richness) nonnatives increased with automobile traffic-a measure of human-generated propagule pressure-and were twice as common in pastures than native grasslands. After accounting for drivers associated with a community's ability to support native species (native species richness and productivity), nonnatives are more common in communities that are regularly seasonally disturbed (pastures and, potentially deciduous forests) and those experiencing more vehicular traffic. These baseline values across the US North America will allow NEON's monitoring mission to document how anthropogenic change-from disturbance to propagule transport, from temperature to trends in local extinction-further shape biotic homogenization.
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Affiliation(s)
- Michael Kaspari
- Geographical Ecology Group, Department of BiologyUniversity of OklahomaNormanOklahomaUSA
- Conservation Ecology CenterSmithsonian's National Zoo and Conservation Biology InstituteFront RoyalVirginiaUSA
| | - Michael D. Weiser
- Geographical Ecology Group, Department of BiologyUniversity of OklahomaNormanOklahomaUSA
| | - Cameron D. Siler
- Geographical Ecology Group, Department of BiologyUniversity of OklahomaNormanOklahomaUSA
- Sam Noble Oklahoma Museum of Natural HistoryUniversity of OklahomaNormanOklahomaUSA
| | - Katie E. Marshall
- Department of ZoologyUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Sierra N. Smith
- Geographical Ecology Group, Department of BiologyUniversity of OklahomaNormanOklahomaUSA
- Sam Noble Oklahoma Museum of Natural HistoryUniversity of OklahomaNormanOklahomaUSA
| | - Katherine M. Stroh
- Sam Noble Oklahoma Museum of Natural HistoryUniversity of OklahomaNormanOklahomaUSA
| | - Kirsten M. de Beurs
- Laboratory of Geo‐Information Science and Remote SensingWageningen University and ResearchWageningenThe Netherlands
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2
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Kaspari M, Weiser MD, Marshall KE, Siler CD, de Beurs K. Temperature-habitat interactions constrain seasonal activity in a continental array of pitfall traps. Ecology 2023; 104:e3855. [PMID: 36054605 DOI: 10.1002/ecy.3855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 07/19/2022] [Accepted: 07/21/2022] [Indexed: 02/01/2023]
Abstract
Activity density (AD), the rate at which animals collectively move through their environment, emerges as the product of a taxon's local abundance and its velocity. We analyze drivers of seasonal AD using 47 localities from the National Ecological Observatory Network (NEON) both to better understand variation in ecosystem rates like pollination and seed dispersal as well as the constraints of using AD to monitor invertebrate populations. AD was measured as volume from biweekly pitfall trap arrays (ml trap-1 14 days-1 ). Pooled samples from 2017 to 2018 revealed AD extrema at most temperatures but with a strongly positive overall slope. However, habitat types varied widely in AD's seasonal temperature sensitivity, from negative in wetlands to positive in mixed forest, grassland, and shrub habitats. The temperature of maximum AD varied threefold across the 47 localities; it tracked the threefold geographic variation in maximum growing season temperature with a consistent gap of ca. 3°C across habitats, a novel macroecological result. AD holds potential as an effective proxy for investigating ecosystem rates driven by activity. However, our results suggest that its use for monitoring insect abundance is complicated by the many ways that both abundance and velocity are constrained by a locality's temperature and plant physiognomy.
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Affiliation(s)
- Michael Kaspari
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, Oklahoma, USA
| | - Michael D Weiser
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, Oklahoma, USA
| | - Katie E Marshall
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Cameron D Siler
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, Oklahoma, USA.,Sam Noble Oklahoma Museum of Natural History, University of Oklahoma, Norman, Oklahoma, USA
| | - Kirsten de Beurs
- Department of Geography and Environmental Sustainability, University of Oklahoma, Norman, Oklahoma, USA
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3
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Kaspari M, Welti EAR. Electrolytes on the prairie: How urine-like additions of Na and K shape the dynamics of a grassland food web. Ecology 2023; 104:e3856. [PMID: 36053835 DOI: 10.1002/ecy.3856] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 07/12/2022] [Indexed: 02/01/2023]
Abstract
The electrolytes Na and K both function to maintain water balance and membrane potential. However, these elements work differently in plants-where K is the primary electrolyte-than in animals-where ATPases require a balanced supply of Na and K. Here, we use monthly factorial additions of Na and K to simulate bovine urine inputs and explore how these electrolytes ramify through a prairie food web. Against a seasonal trend of increasing grass biomass and decreasing water and elemental tissue concentrations, +K and +Na plots boosted water content and, when added together, plant biomass. Compared to control plots, +Na and +K plots increased element concentrations in above-ground plant tissue early in summer and decreased them in September. Simultaneously, invertebrate abundance on Na and K additions were sequentially higher and lower than control plots from June to September and were most suppressed when grass was most nutrient rich. K was the more effective plant electrolyte, but Na frequently promoted similar changes in grass ionomes. The soluble/leachable ions of Na and K showed significant ability to shape plant growth, water content, and the 15-element ionome, with consequences for higher trophic levels. Grasslands with high inputs of Na and K-via large mammal grazers or coastal aerosol deposition-likely enhance the ability of plants to adjust their above-ground ionomes, with dramatic consequences for the distribution of invertebrate consumers.
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Affiliation(s)
- Michael Kaspari
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, Oklahoma, USA
| | - Ellen A R Welti
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, Oklahoma, USA.,Senckenberg Research Institute and Natural History Museum Frankfurt, Gelnhausen, Germany
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4
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Blair J, Weiser MD, de Beurs K, Kaspari M, Siler C, Marshall KE. Embracing imperfection: Machine-assisted invertebrate classification in real-world datasets. ECOL INFORM 2022. [DOI: 10.1016/j.ecoinf.2022.101896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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5
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Weiser MD, Siler CD, Smith SN, Marshall KE, McLaughlin JF, Miller MJ, Kaspari M. Robust metagenomic evidence that local assemblage richness increases with latitude in ground‐active invertebrates of North America. OIKOS 2022. [DOI: 10.1111/oik.08791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Michael D. Weiser
- Univ. of Oklahoma, Dept of Biology Norman OK USA
- Univ. of Oklahoma, Geographical Ecology Group Norman OK USA
| | - Cameron D. Siler
- Univ. of Oklahoma, Dept of Biology Norman OK USA
- Sam Noble Oklahoma Museum of Natural History Norman OK USA
| | - Sierra N. Smith
- Univ. of Oklahoma, Dept of Biology Norman OK USA
- Sam Noble Oklahoma Museum of Natural History Norman OK USA
| | | | - Jessica F. McLaughlin
- Univ. of Oklahoma, Dept of Biology Norman OK USA
- Sam Noble Oklahoma Museum of Natural History Norman OK USA
| | - Matthew J. Miller
- Univ. of Oklahoma, Dept of Biology Norman OK USA
- Reneco International Wildlife Consultants Abu Dhabi UAE
| | - Michael Kaspari
- Univ. of Oklahoma, Dept of Biology Norman OK USA
- Univ. of Oklahoma, Geographical Ecology Group Norman OK USA
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6
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Bujan J, Nottingham AT, Velasquez E, Meir P, Kaspari M, Yanoviak SP. Tropical ant community responses to experimental soil warming. Biol Lett 2022; 18:20210518. [PMID: 35382584 PMCID: PMC8984296 DOI: 10.1098/rsbl.2021.0518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 03/07/2022] [Indexed: 11/12/2022] Open
Abstract
Climate change is one of the primary agents of the global decline in insect abundance. Because of their narrow thermal ranges, tropical ectotherms are predicted to be most threatened by global warming, yet tests of this prediction are often confounded by other anthropogenic disturbances. We used a tropical forest soil warming experiment to directly test the effect of temperature increase on litter-dwelling ants. Two years of continuous warming led to a change in ant community between warming and control plots. Specifically, six ant genera were recorded only on warming plots, and one genus only on control plots. Wasmannia auropuctata, a species often invasive elsewhere but native to this forest, was more abundant in warmed plots. Ant recruitment at baits was best predicted by soil surface temperature and ant heat tolerance. These results suggest that heat tolerance is useful for predicting changes in daily foraging activity, which is directly tied to colony fitness. We show that a 2-year increase in temperature (of 2-4°C) can have a profound effect on the most abundant insects, potentially favouring species with invasive traits and moderate heat tolerances.
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Affiliation(s)
- Jelena Bujan
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
- Department of Biology, University of Louisville, Louisville, KY 40292, USA
| | - Andrew T. Nottingham
- School of Geography, University of Leeds, Leeds LS2 9JT, UK
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Republic of Panama
| | - Esther Velasquez
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Republic of Panama
| | - Patrick Meir
- School of Geosciences, University of Edinburgh, Edinburgh EH9 3FF, UK
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, ACT 2601, Australia
| | - Michael Kaspari
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, OK 73019, USA
| | - Stephen P. Yanoviak
- Department of Biology, University of Louisville, Louisville, KY 40292, USA
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Republic of Panama
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7
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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8
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Kaspari M, Joern A, Welti EAR. How and why grasshopper community maturation rates are slowing on a North American tall grass prairie. Biol Lett 2022; 18:20210510. [PMID: 35078328 PMCID: PMC8790374 DOI: 10.1098/rsbl.2021.0510] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 12/13/2021] [Indexed: 01/28/2023] Open
Abstract
Invertebrate growth rates have been changing in the Anthropocene. We examine rates of seasonal maturation in a grasshopper community that has been declining annually greater than 2% a year over 34 years. As this grassland has experienced a 1°C increase in temperature, higher plant biomass and lower nutrient densities, the community is maturing more slowly. Community maturation had a nutritional component: declining in years/watersheds with lower plant nitrogen. The effects of fire frequency were consistent with effects of plant nitrogen. Principal components analysis also suggests associated changes in species composition-declines in the densities of grass feeders were associated with declines in community maturation rates. We conclude that slowed maturation rates-a trend counteracted by frequent burning-likely contribute to long-term decline of this dominant herbivore.
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Affiliation(s)
- Michael Kaspari
- Geographical Ecology Group, University of Oklahoma, Norman, OK, USA
| | - Anthony Joern
- Division of Biology, Kansas State University, Manhattan, KS, USA
| | - Ellen A. R. Welti
- Department of River Ecology and Conservation, Senckenberg Research Institute and Natural History Museum Frankfurt, Gelnhausen, Germany
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9
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Roeder KA, Benson BR, Weiser MD, Kaspari M. Testing the role of body size and litter depth on invertebrate diversity across six forests in North America. Ecology 2021; 103:e03601. [PMID: 34820828 DOI: 10.1002/ecy.3601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 11/01/2021] [Accepted: 11/16/2021] [Indexed: 11/06/2022]
Abstract
Ecologists search for rules by which traits dictate the abundance and distribution of species. Here we search for rules that apply across three common taxa of litter invertebrates in six North American forests from Panama to Oregon. We use image analysis to quantify the abundance and body size distributions of mites, springtails, and spiders in 21 1-m2 plots per forest. We contrast three hypotheses: two of which focus on trait-abundance relationships and a third linking abundance to species richness. Despite three orders of magnitude variation in size, the predicted negative relationship between mean body size and abundance per area occurred in only 18% of cases, never for large bodied taxa like spiders. We likewise found only 18% of tests supported our prediction that increasing litter depth allows for high abundance; two-thirds of which occurred at a single deciduous forest in Massachusetts. In contrast, invertebrate abundance constrained species richness 76% of the time. Our results suggest that body size and habitat volume in brown food webs are rarely good predictors of variation in abundance, but that variation in diversity is generally well predicted by abundance.
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Affiliation(s)
- Karl A Roeder
- USDA, Agricultural Research Service, North Central Agricultural Research Laboratory, Brookings, South Dakota, 57006, USA.,Department of Biology, Geographical Ecology Group, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Brittany R Benson
- Department of Biology, Geographical Ecology Group, University of Oklahoma, Norman, Oklahoma, 73019, USA.,Ecology Research Group, Faculty of Biosciences and Aquaculture, Nord University, Steinkjer, 7729, Norway
| | - Michael D Weiser
- Department of Biology, Geographical Ecology Group, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Michael Kaspari
- Department of Biology, Geographical Ecology Group, University of Oklahoma, Norman, Oklahoma, 73019, USA
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10
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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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11
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Kaspari M, Weiser MD, Marshall KE, Miller M, Siler C, de Beurs K. Activity density at a continental scale: What drives invertebrate biomass moving across the soil surface? Ecology 2021; 103:e03542. [PMID: 34614206 DOI: 10.1002/ecy.3542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 09/08/2021] [Accepted: 09/22/2021] [Indexed: 11/08/2022]
Abstract
Activity density (AD), the rate that an individual taxon or its biomass moves through the environment, is used both to monitor communities and quantify the potential for ecosystem work. The Abundance Velocity Hypothesis posited that AD increases with aboveground net primary productivity (ANPP) and is a unimodal function of temperature. Here we show that, at continental extents, increasing ANPP may have nonlinear effects on AD: increasing abundance, but decreasing velocity as accumulating vegetation interferes with movement. We use 5 yr of data from the NEON invertebrate pitfall trap arrays including 43 locations and four habitat types for a total of 77 habitat-site combinations to evaluate continental drivers of invertebrate AD. ANPP and temperature accounted for one-third to 92% of variation in AD. As predicted, AD was a unimodal function of temperature in forests and grasslands but increased linearly in open scrublands. ANPP yielded further nonlinear effects, generating unimodal AD curves in wetlands, and bimodal curves in forests. While all four habitats showed no AD trends over 5 yr of sampling, these nonlinearities suggest that trends in AD, often used to infer changes in insect abundance, will vary qualitatively across ecoregions.
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Affiliation(s)
- Michael Kaspari
- Department of Biology, Geographical Ecology Group, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Michael D Weiser
- Department of Biology, Geographical Ecology Group, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Katie E Marshall
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
| | - Matthew Miller
- Department of Biology, Geographical Ecology Group, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Cameron Siler
- Department of Biology, Geographical Ecology Group, University of Oklahoma, Norman, Oklahoma, 73019, USA.,Sam Noble Oklahoma Museum of Natural History, University of Oklahoma, Norman, Oklahoma, 73072-7029, USA
| | - Kirsten de Beurs
- Department of Geography and Environmental Sustainability, University of Oklahoma, Norman, Oklahoma, 73019, USA
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12
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Prather RM, Welti EAR, Kaspari M. Trophic differences regulate grassland food webs: herbivores track food quality and predators select for habitat volume. Ecology 2021; 102:e03453. [PMID: 34165805 DOI: 10.1002/ecy.3453] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 05/13/2021] [Indexed: 11/09/2022]
Abstract
The impacts of altered biogeochemical cycles on ecological systems are likely to vary with trophic level. Predicting how these changes will affect ecological food webs is further complicated by human activities, which are simultaneously altering the availability of macronutrients like nitrogen (N) and phosphorus (P), and micronutrients such as sodium (Na). Here we contrast three hypotheses that predict how increasing nutrient availability will shape grassland food webs. We conducted a distributed factorial fertilization experiment (N and P crossed with NaCl) across four North American grasslands, quantifying the responses of aboveground plant biomass and volume, plant tissue and soil elemental concentrations, as well as the abundance of five arthropod functional groups. Fertilization with N and P increased plant biomass and foliar N and P concentrations in grasses but not forbs. Fertilization with Na had no effect on plant biomass but increased foliar Na concentrations. Consistent with the nutrient limitation hypothesis, we found strong evidence of nutrient limitation for insect herbivores across the four sites with sucking (phloem and xylem feeding) herbivores increasing in abundance with NP fertilization and chewing herbivores increasing in response to both Na and NP fertilization, and a trend for increased response of arthropods to lower plant nutrient availability. We found no evidence for an interaction of NaCl and NP on arthropod abundance as predicted by the serial colimitation hypothesis. Finally, consistent with the ecosystem size hypothesis, predator and parasitoid abundances increased with plant volume, but not fertilization. Our results suggest these functional group-specific responses to changes in plant nutrients and structure are key to predicting the future of grassland food webs in an era with increasing use of N and P fertilizers, and increasing terrestrial inputs of Na from road salt, saline irrigation water, and aerosols due to rising sea levels.
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Affiliation(s)
- Rebecca M Prather
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA.,Department of Biological Science, Florida State University, Tallahassee, Florida, 32306, USA
| | - Ellen A R Welti
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA.,Senckenberg Research Institute and Natural History Museum Frankfurt, Gelnhausen, 63571, Germany
| | - Michael Kaspari
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA
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13
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Roeder KA, Bujan J, Beurs KM, Weiser MD, Kaspari M. Thermal traits predict the winners and losers under climate change: an example from North American ant communities. Ecosphere 2021. [DOI: 10.1002/ecs2.3645] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Affiliation(s)
- Karl A. Roeder
- Agricultural Research Service North Central Agricultural Research Laboratory USDA Brookings South Dakota57006USA
- Department of Biology Geographical Ecology Group University of Oklahoma Norman Oklahoma73019USA
| | - Jelena Bujan
- Department of Biology Geographical Ecology Group University of Oklahoma Norman Oklahoma73019USA
- Department of Ecology and Evolution University of Lausanne Lausanne Switzerland
| | - Kirsten M. Beurs
- Department of Geography and Environmental Sustainability University of Oklahoma Norman Oklahoma73019USA
| | - Michael D. Weiser
- Department of Biology Geographical Ecology Group University of Oklahoma Norman Oklahoma73019USA
| | - Michael Kaspari
- Department of Biology Geographical Ecology Group University of Oklahoma Norman Oklahoma73019USA
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14
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Kaspari M, de Beurs KM, Welti EAR. How and why plant ionomes vary across North American grasslands and its implications for herbivore abundance. Ecology 2021; 102:e03459. [PMID: 34171182 DOI: 10.1002/ecy.3459] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 03/29/2021] [Accepted: 05/13/2021] [Indexed: 12/20/2022]
Abstract
Plant elemental content can vary up to 1,000-fold across grasslands, with implications for the herbivores the plants feed. We contrast the regulation, in grasses and forbs, of 12 elements essential to plants and animals (henceforth plant-essential), 7 essential to animals but not plants (animal-essential) and 6 with no known metabolic function (nonessential). Four hypotheses accounted for up to two thirds of the variation in grass and forb ionomes across 54 North American grasslands. Consistent with the supply-side hypothesis, the plant-essential ionome of both forbs and grasses tracked soil availability. Grass ionomes were more likely to harvest even nonessential elements like Cd and Sr. Consistent with the grazing hypothesis, cattle-grazed grasslands also accumulated a handful of metals like Cu and Cr. Consistent with the NP-catalysis hypothesis, increases in the macronutrients N and P in grasses were associated with higher densities of cofactors like Zn and Cu. The plant-essential elements of forbs, in contrast, consistently varied as per the nutrient-dilution hypothesis-there was a decrease in elemental parts per million with increasing local carbohydrate production. Combined, these data fit a working hypothesis that grasses maintain lower elemental densities and survive on nutrient-poor patches by opportunistically harvesting soil nutrients. In contrast, nutrient-rich forbs use episodes of high precipitation and temperature to build new carbohydrate biomass, raising leaves higher to compete for light, but diluting the nutrient content in every bite of tissue. Herbivores of forbs may thus be particularly prone to increases in pCO2 via nutrient dilution.
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Affiliation(s)
- Michael Kaspari
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Kirsten M de Beurs
- Department of Geography and Environmental Sustainability, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Ellen A R Welti
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA.,Senckenberg Research Institute and Natural History Museum Frankfurt, Gelnhausen, 63571, Germany
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15
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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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16
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Ozment KA, Welti EAR, Shaffer M, Kaspari M. Tracking nutrients in space and time: Interactions between grazing lawns and drought drive abundances of tallgrass prairie grasshoppers. Ecol Evol 2021; 11:5413-5423. [PMID: 34026017 PMCID: PMC8131794 DOI: 10.1002/ece3.7435] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/11/2021] [Accepted: 02/19/2021] [Indexed: 12/13/2022] Open
Abstract
We contrast the response of arthropod abundance and composition to bison grazing lawns during a drought and non-drought year, with an emphasis on acridid grasshoppers, an important grassland herbivore.Grazing lawns are grassland areas where regular grazing by mammalian herbivores creates patches of short-statured, high nutrient vegetation. Grazing lawns are predictable microsites that modify microclimate, plant structure, community composition, and nutrient availability, with likely repercussions for arthropod communities.One year of our study occurred during an extreme drought. Drought mimics some of the effects of mammalian grazers: decreasing above-ground plant biomass while increasing plant foliar percentage nitrogen.We sampled arthropods and nutrient availability on and nearby ("off") 10 bison-grazed grazing lawns in a tallgrass prairie in NE Kansas. Total grasshopper abundance was higher on grazing lawns and the magnitude of this difference increased in the wetter year of 2019 compared to 2018, when drought led to high grass foliar nitrogen concentrations on and off grazing lawns. Mixed-feeding grasshopper abundances were consistently higher on grazing lawns while grass-feeder and forb-feeder abundances were higher on lawns only in 2019, the wetter year. In contrast, the abundance of other arthropods (e.g., Hemiptera, Hymenoptera, and Araneae) did not differ on and off lawns, but increased overall in 2019, relative to the drought of 2018.Understanding these local scale patterns of abundances and community composition improves predictability of arthropod responses to ongoing habitat change.
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Affiliation(s)
- Katerina A. Ozment
- Geographical Ecology GroupDepartment of BiologyUniversity of OklahomaNormanOKUSA
| | - Ellen A. R. Welti
- Geographical Ecology GroupDepartment of BiologyUniversity of OklahomaNormanOKUSA
- Senckenberg Research Institute and Natural History Museum FrankfurtGelnhausenGermany
| | | | - Michael Kaspari
- Geographical Ecology GroupDepartment of BiologyUniversity of OklahomaNormanOKUSA
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17
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Welti EAR, Joern A, Ellison AM, Lightfoot DC, Record S, Rodenhouse N, Stanley EH, Kaspari M. Studies of insect temporal trends must account for the complex sampling histories inherent to many long-term monitoring efforts. Nat Ecol Evol 2021; 5:589-591. [DOI: 10.1038/s41559-021-01424-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 02/23/2021] [Indexed: 11/10/2022]
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18
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Affiliation(s)
- Taylor N. Peterson
- Geographical Ecology Group Department of Biology University of Oklahoma Norman Oklahoma73019USA
| | - Ellen A. R. Welti
- Geographical Ecology Group Department of Biology University of Oklahoma Norman Oklahoma73019USA
- Senckenberg Research Institute and Natural History Museum Frankfurt Gelnhausen Germany
| | - Michael Kaspari
- Geographical Ecology Group Department of Biology University of Oklahoma Norman Oklahoma73019USA
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19
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Blair J, Weiser MD, Kaspari M, Miller M, Siler C, Marshall KE. Robust and simplified machine learning identification of pitfall trap-collected ground beetles at the continental scale. Ecol Evol 2020; 10:13143-13153. [PMID: 33304524 PMCID: PMC7713910 DOI: 10.1002/ece3.6905] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/10/2020] [Accepted: 09/18/2020] [Indexed: 11/10/2022] Open
Abstract
Insect populations are changing rapidly, and monitoring these changes is essential for understanding the causes and consequences of such shifts. However, large-scale insect identification projects are time-consuming and expensive when done solely by human identifiers. Machine learning offers a possible solution to help collect insect data quickly and efficiently.Here, we outline a methodology for training classification models to identify pitfall trap-collected insects from image data and then apply the method to identify ground beetles (Carabidae). All beetles were collected by the National Ecological Observatory Network (NEON), a continental scale ecological monitoring project with sites across the United States. We describe the procedures for image collection, image data extraction, data preparation, and model training, and compare the performance of five machine learning algorithms and two classification methods (hierarchical vs. single-level) identifying ground beetles from the species to subfamily level. All models were trained using pre-extracted feature vectors, not raw image data. Our methodology allows for data to be extracted from multiple individuals within the same image thus enhancing time efficiency, utilizes relatively simple models that allow for direct assessment of model performance, and can be performed on relatively small datasets.The best performing algorithm, linear discriminant analysis (LDA), reached an accuracy of 84.6% at the species level when naively identifying species, which was further increased to >95% when classifications were limited by known local species pools. Model performance was negatively correlated with taxonomic specificity, with the LDA model reaching an accuracy of ~99% at the subfamily level. When classifying carabid species not included in the training dataset at higher taxonomic levels species, the models performed significantly better than if classifications were made randomly. We also observed greater performance when classifications were made using the hierarchical classification method compared to the single-level classification method at higher taxonomic levels.The general methodology outlined here serves as a proof-of-concept for classifying pitfall trap-collected organisms using machine learning algorithms, and the image data extraction methodology may be used for nonmachine learning uses. We propose that integration of machine learning in large-scale identification pipelines will increase efficiency and lead to a greater flow of insect macroecological data, with the potential to be expanded for use with other noninsect taxa.
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Affiliation(s)
- Jarrett Blair
- Department of ZoologyUniversity of British ColumbiaVancouverBCCanada
| | | | | | | | - Cameron Siler
- Department of BiologyUniversity of OklahomaNormanOKUSA
- Sam Noble Oklahoma Museum of Natural HistoryUniversity of OklahomaNormanOKUSA
| | - Katie E. Marshall
- Department of ZoologyUniversity of British ColumbiaVancouverBCCanada
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20
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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21
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Prather RM, Castillioni K, Welti EAR, Kaspari M, Souza L. Abiotic factors and plant biomass, not plant diversity, strongly shape grassland arthropods under drought conditions. Ecology 2020; 101:e03033. [PMID: 32112407 DOI: 10.1002/ecy.3033] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 01/30/2020] [Accepted: 02/24/2020] [Indexed: 11/07/2022]
Abstract
Arthropod abundance and diversity often track plant biomass and diversity at the local scale. However, under altered precipitation regimes and anthropogenic disturbances, plant-arthropod relationships are expected to be increasingly controlled by abiotic, rather than biotic, factors. We used an experimental precipitation gradient combined with human management in a temperate mixed-grass prairie to examine (1) how two drivers, altered precipitation and biomass removal, can synergistically affect abiotic factors and plant communities and (2) how these effects can cascade upward, impacting the arthropod food web. Both drought and hay harvest increased soil surface temperature, and drought decreased soil moisture. Arthropod abundance decreased with low soil moisture and, contrary to our predictions, decreased with increased plant biomass. Arthropod diversity increased with soil moisture, decreased with high surface temperatures, and tracked arthropod abundance but was unaffected by plant diversity or quality. Our experiment demonstrates that arthropod abundance is directly constrained by abiotic factors and plant biomass, in turn constraining local arthropod diversity. If robust, this result suggests climate change in the southern Great Plains may directly reduce arthropod diversity.
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Affiliation(s)
- Rebecca M Prather
- Department of Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Karen Castillioni
- Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Ellen A R Welti
- Department of Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Michael Kaspari
- Department of Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Lara Souza
- Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA
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22
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Bujan J, Roeder KA, Yanoviak SP, Kaspari M. Seasonal plasticity of thermal tolerance in ants. Ecology 2020; 101:e03051. [PMID: 32239508 DOI: 10.1002/ecy.3051] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 12/19/2019] [Accepted: 03/16/2020] [Indexed: 11/06/2022]
Abstract
Analyses of heat tolerance in insects often suggest that this trait is relatively invariant, leading to the use of fixed thermal maxima in models predicting future distribution of species in a warming world. Seasonal environments expose populations to a wide annual temperature variation. To evaluate the simplifying assumption of invariant thermal maxima, we quantified heat tolerance of 26 ant species across three seasons that vary two-fold in mean temperature. Our ultimate goal was to test the hypothesis that heat tolerance tracks monthly temperature. Ant foragers tested at the end of the summer, in September, had higher average critical thermal maximum (CTmax ) compared to those in March and December. Four out of five seasonal generalists, species actively foraging in all three focal months, had, on average, 6°C higher CTmax in September. The invasive fire ant, Solenopsis invicta, was among the thermally plastic species, but the native thermal specialists still maintained higher CTmax than S. invicta. Our study shows that heat tolerance can be plastic, and this should be considered when examining species-level adaptations. Moreover, the plasticity of thermal traits, while potentially costly, may also generate a competitive advantage over species with fixed traits and promote resilience to climate change.
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Affiliation(s)
- Jelena Bujan
- Department of Biology, University of Louisville, Louisville, Kentucky, 40292, USA.,Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Karl A Roeder
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA.,Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, Illinois, 61801, USA
| | - Stephen P Yanoviak
- Department of Biology, University of Louisville, Louisville, Kentucky, 40292, USA.,Smithsonian Tropical Research Institute, Apartado 0843, Balboa, Republic of Panama
| | - Michael Kaspari
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA
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23
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Welti EAR, Prather RM, Sanders NJ, de Beurs KM, Kaspari M. Bottom-up when it is not top-down: Predators and plants control biomass of grassland arthropods. J Anim Ecol 2020; 89:1286-1294. [PMID: 32115723 DOI: 10.1111/1365-2656.13191] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Accepted: 12/20/2019] [Indexed: 11/30/2022]
Abstract
We investigate where bottom-up and top-down control regulates ecological communities as a mechanism linking ecological gradients to the geography of consumer abundance and biomass. We use standardized surveys of 54 North American grasslands to test alternate hypotheses predicting 100-fold shifts in the biomass of four common grassland arthropod taxa-Auchenorrhyncha, sucking herbivores, Acrididae, chewing herbivores, Tettigoniidae, omnivores, and Araneae, predators. Bottom-up models predict that consumer biomass tracks plant quantity (e.g. productivity and standing biomass) and quality (nutrient content) and that ectotherm access to food increases with temperature. Each of the focal trophic groups responded differently to these drivers: the biomass of sucking herbivores and omnivores increased with plant biomass; that of chewing herbivores tracked plant quality; and predator biomass did not depend on plant quality, plant quantity or temperature. The Exploitation Ecosystem Hypothesis is a top-down hypothesis that predicts a shift from resource limitation of herbivores when plant production is low, to predator limitation when plant production is high. In grasslands where spider biomass was low, herbivore biomass increased with plant biomass, whereas bottom-up structuring was not evident when spiders were abundant. Furthermore, neither predator biomass nor trophic position (via stable isotope analysis) increased with plant biomass, suggesting predators themselves are top-down limited. Stable isotope analysis revealed that trophic position of the chewing herbivore and omnivore increased significantly with plant biomass, suggesting these groups increased scavenging and meat consumption in grasslands with higher carbohydrate availability. Taken together, our snapshot sampling documents gradients of food web structure across 54 grasslands, consistent with multiple hypotheses of bottom-up and top-down regulation.
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Affiliation(s)
- Ellen A R Welti
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, OK, USA
| | - Rebecca M Prather
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, OK, USA
| | - Nathan J Sanders
- The Environmental Program, Rubenstein School of Environment and Natural Resources, University of Vermont, Burlington, VT, USA
| | - Kirsten M de Beurs
- Department of Geography and Environmental Sustainability, University of Oklahoma, Norman, OK, USA
| | - Michael Kaspari
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, OK, USA
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24
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Kaspari M, Welti EAR, Beurs KM. The nutritional geography of ants: Gradients of sodium and sugar limitation across North American grasslands. J Anim Ecol 2019; 89:276-284. [DOI: 10.1111/1365-2656.13120] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 09/18/2019] [Indexed: 01/02/2023]
Affiliation(s)
- Michael Kaspari
- Geographical Ecology Group Department of Biology University of Oklahoma Norman OK USA
| | - Ellen A. R. Welti
- Geographical Ecology Group Department of Biology University of Oklahoma Norman OK USA
| | - Kirsten M. Beurs
- Department of Geography and Environmental Sustainability University of Oklahoma Norman OK USA
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25
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Affiliation(s)
- Rebecca M. Prather
- Department of Biology Graduate Program in Ecology and Evolutionary Biology University of Oklahoma Norman Oklahoma 73019 USA
| | - Michael Kaspari
- Department of Biology Graduate Program in Ecology and Evolutionary Biology University of Oklahoma Norman Oklahoma 73019 USA
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26
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Kaspari M, Bujan J, Roeder KA, Beurs K, Weiser MD. Species energy and Thermal Performance Theory predict 20‐yr changes in ant community abundance and richness. Ecology 2019; 100:e02888. [DOI: 10.1002/ecy.2888] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/25/2019] [Accepted: 08/26/2019] [Indexed: 01/12/2023]
Affiliation(s)
- Michael Kaspari
- Geographical Ecology Group Department of Biology University of Oklahoma Norman Oklahoma 73019 USA
| | - Jelena Bujan
- Geographical Ecology Group Department of Biology University of Oklahoma Norman Oklahoma 73019 USA
- Department of Biology University of Louisville Louisville Kentucky 40208 USA
| | - Karl A. Roeder
- Geographical Ecology Group Department of Biology University of Oklahoma Norman Oklahoma 73019 USA
| | - Kirsten Beurs
- Department of Geography and Sustainability University of Oklahoma Norman Oklahoma 73019 USA
| | - Michael D. Weiser
- Geographical Ecology Group Department of Biology University of Oklahoma Norman Oklahoma 73019 USA
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27
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Buzzard V, Michaletz ST, Deng Y, He Z, Ning D, Shen L, Tu Q, Van Nostrand JD, Voordeckers JW, Wang J, Weiser MD, Kaspari M, Waide RB, Zhou J, Enquist BJ. Author Correction: Continental scale structuring of forest and soil diversity via functional traits. Nat Ecol Evol 2019; 3:1607. [PMID: 31582820 DOI: 10.1038/s41559-019-1014-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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Affiliation(s)
- Vanessa Buzzard
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA.
| | - Sean T Michaletz
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA.,Los Alamos National Laboratory, Earth and Environmental Sciences Division, Los Alamos, NM, USA.,Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Ye Deng
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, OK, USA.,Chinese Academy of Sciences, Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Beijing, China
| | - Zhili He
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, OK, USA.,Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, China.,Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, China
| | - Daliang Ning
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, OK, USA
| | - Lina Shen
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, OK, USA
| | - Qichao Tu
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, OK, USA.,Institute of Marine Science and Technology, Shandong University, Qingdao, China
| | - Joy D Van Nostrand
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, OK, USA
| | - James W Voordeckers
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, OK, USA
| | - Jianjun Wang
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, OK, USA
| | - Michael D Weiser
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, OK, USA
| | - Michael Kaspari
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, OK, USA.,Smithsonian Tropical Research Institute, Balboa, Republic of Panama
| | - Robert B Waide
- Department of Biology, University of New Mexico, Albuquerque, NM, USA
| | - Jizhong Zhou
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, OK, USA.,Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
| | - Brian J Enquist
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA.,The Santa Fe Institute, Santa Fe, NM, USA
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28
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Lucas JM, Gora E, Salzberg A, Kaspari M. Antibiotics as chemical warfare across multiple taxonomic domains and trophic levels in brown food webs. Proc Biol Sci 2019; 286:20191536. [PMID: 31551054 PMCID: PMC6784713 DOI: 10.1098/rspb.2019.1536] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 08/30/2019] [Indexed: 12/14/2022] Open
Abstract
Bacteria and fungi secrete antibiotics to suppress and kill other microbes, but can these compounds be agents of competition against macroorganisms? We explore how one competitive tactic, antibiotic production, can structure the composition and function of brown food webs. This aspect of warfare between microbes and invertebrates is particularly important today as antibiotics are introduced into ecosystems via anthropogenic activities, but the ecological implications of these introductions are largely unknown. We hypothesized that antimicrobial compounds act as agents of competition against invertebrate and microbial competitors. Using field-like mesocosms, we tested how antifungal and antibacterial compounds influence microbes, invertebrates, and decomposition in the brown food web. Both antibiotics changed prokaryotic microbial community composition, but only the antibacterial changed invertebrate composition. Antibacterials reduced the abundance of invertebrate detritivores by 34%. However, the addition of antimicrobials did not ramify up the food web as predator abundances were unaffected. Decomposition rates did not change. To test the mechanisms of antibiotic effects, we provided antibiotic-laden water to individual invertebrate detritivores in separate microcosm experiments. We found that the antibiotic compounds can directly harm invertebrate taxa, probably through a disruption of endosymbionts. Combined, our results show that antibiotic compounds could be an effective weapon for microbes to compete against both microbial and invertebrate competitors. In the context of human introductions, the detrimental effects of antibiotics on invertebrate communities indicates that the scope of this anthropogenic disturbance is much greater than previously expected.
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Affiliation(s)
- Jane M. Lucas
- Department of Soil and Water Systems, University of Idaho, Moscow, ID 83843, USA
- Department of Biology, Graduate Program in Ecology and Evolutionary Biology, University of Oklahoma, Norman, OK 73069, USA
| | - Evan Gora
- Department of Biology, University of Louisville, Louisville, KY 40292, USA
| | - Annika Salzberg
- Department of Entomology, Cornell University, Ithaca, NY 14850, USA
| | - Michael Kaspari
- Department of Biology, Graduate Program in Ecology and Evolutionary Biology, University of Oklahoma, Norman, OK 73069, USA
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29
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Buzzard V, Michaletz ST, Deng Y, He Z, Ning D, Shen L, Tu Q, Van Nostrand JD, Voordeckers JW, Wang J, Weiser MD, Kaspari M, Waide RB, Zhou J, Enquist BJ. Continental scale structuring of forest and soil diversity via functional traits. Nat Ecol Evol 2019; 3:1298-1308. [DOI: 10.1038/s41559-019-0954-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Accepted: 06/25/2019] [Indexed: 11/09/2022]
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30
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Kaspari M, Beurs K. On the geography of activity: productivity but not temperature constrains discovery rates by ectotherm consumers. Ecosphere 2019. [DOI: 10.1002/ecs2.2536] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Michael Kaspari
- Geographical Ecology Group Department of Biology University of Oklahoma Norman Oklahoma 73019 USA
| | - Kirsten Beurs
- Department of Geography and Environmental Sustainability University of Oklahoma Norman Oklahoma 73019 USA
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31
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Weiser MD, Ning D, Buzzard V, Michaletz ST, He Z, Enquist BJ, Waide RB, Zhou J, Kaspari M. Thermal disruption of soil bacterial assemblages decreases diversity and assemblage similarity. Ecosphere 2019. [DOI: 10.1002/ecs2.2598] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Michael D. Weiser
- Geographical Ecology Group; Department of Biology; University of Oklahoma; Norman Oklahoma USA
| | - Daliang Ning
- Institute for Environmental Genomics; Department of Microbiology and Plant Biology; School of Civil Engineering and Environmental Sciences; University of Oklahoma; Norman Oklahoma USA
- State Key Joint Laboratory of Environment Simulation and Pollution Control; School of Environment; Tsinghua University; Beijing China
| | - Vanessa Buzzard
- Department of Ecology and Evolutionary Biology; University of Arizona; Tucson Arizona USA
| | - Sean T. Michaletz
- Department of Ecology and Evolutionary Biology; University of Arizona; Tucson Arizona USA
- Department of Botany and Biodiversity Research Centre; University of British Columbia; Vancouver British Columbia Canada
| | - Zhili He
- Institute for Environmental Genomics; Department of Microbiology and Plant Biology; School of Civil Engineering and Environmental Sciences; University of Oklahoma; Norman Oklahoma USA
- Environmental Microbiome Research Center; School of Environmental Science and Engineering; Sun Yat-sen University; Guangzhou China
| | - Brian J. Enquist
- Department of Ecology and Evolutionary Biology; University of Arizona; Tucson Arizona USA
- Santa Fe Institute; Santa Fe New Mexico USA
| | - Robert B. Waide
- Department of Biology; University of New Mexico; Albuquerque New Mexico USA
| | - Jizhong Zhou
- Institute for Environmental Genomics; Department of Microbiology and Plant Biology; School of Civil Engineering and Environmental Sciences; University of Oklahoma; Norman Oklahoma USA
- State Key Joint Laboratory of Environment Simulation and Pollution Control; School of Environment; Tsinghua University; Beijing China
- Earth and Environmental Sciences; Lawrence Berkeley National Laboratory; Berkeley California USA
| | - Michael Kaspari
- Geographical Ecology Group; Department of Biology; University of Oklahoma; Norman Oklahoma USA
- Graduate Program in Ecology and Evolutionary Biology; University of Oklahoma; Norman Oklahoma USA
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32
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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33
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Bujan J, Wright SJ, Kaspari M. Biogeochemistry and forest composition shape nesting patterns of a dominant canopy ant. Oecologia 2018; 189:221-230. [PMID: 30506443 DOI: 10.1007/s00442-018-4314-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 11/21/2018] [Indexed: 11/30/2022]
Abstract
Humans are increasing nutrient deposition across the globe, and we know little about how these changes influence consumer populations in tropical rainforests. We used a long-term fertilization experiment conducted in a Panamanian forest to explore how nutrient availability and tree traits affect abundance of a higher-level consumer. We added nitrogen, phosphorus and potassium in a factorial design for 18 years. Given that phosphorus often limits ecosystem processes in lowland tropical forests, and added nitrogen reduces insect abundance in our experiment, we first hypothesized that phosphorus addition would increase nest density and nest size of Azteca chartifex ants while nitrogen addition would have the opposite effects. We found 48% lower nest density in the canopy of nitrogen addition plots relative to plots that did not receive nitrogen. Phosphorus addition did not affect nest density or size. These nutrient effects were not diminished by the selectivity of host trees. In general, larger trees held more nests, despite their low frequencies across the forest, while some abundant species (e.g., palms) were rarely used. We further predicted higher nest frequency on trees with extrafloral nectaries, because this ant fuels its large colonies with extrafloral nectar. Despite the non-random distribution of A. chartifex nests, across tree species and nutrient treatments, trees with extrafloral nectaries did not host more nests. Our study suggests that areas of a tropical lowland forest which are not oversaturated with nitrogen, and contain large trees, have higher nest density. This could enable A. chartifex in similar areas to outcompete other ants due to high abundance.
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Affiliation(s)
- Jelena Bujan
- Department of Biology, University of Louisville, Louisville, KY, 40292, USA. .,Department of Biology, Graduate Program in Ecology and Evolutionary Biology, University of Oklahoma, Norman, OK, 73019, USA.
| | - S Joseph Wright
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Republic of Panama
| | - Michael Kaspari
- Department of Biology, Graduate Program in Ecology and Evolutionary Biology, University of Oklahoma, Norman, OK, 73019, USA
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Kaspari M, Roeder KA, Benson B, Weiser MD, Sanders NJ. Sodium co-limits and catalyzes macronutrients in a prairie food web. Ecology 2018; 98:315-320. [PMID: 27936500 DOI: 10.1002/ecy.1677] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 11/15/2016] [Accepted: 11/22/2016] [Indexed: 11/08/2022]
Abstract
Nitrogen and phosphorus frequently limit terrestrial plant production, but have a mixed record in regulating the abundance of terrestrial invertebrates. We contrasted four ways that Na could interact with an NP fertilizer to shape the plants and invertebrates of an inland prairie. We applied NP and Na to m2 plots in a factorial design. Aboveground invertebrate abundance was independently co-limited by NaCl and NP, but with +NP plots supporting more individuals. We suggest the disparity arises because NP enhanced plant height by 35% (1 SD) over controls, providing both food and habitat, whereas NaCl provides only food. Belowground invertebrates showed evidence of serial co-limitation, where NaCl additions alone were ineffectual, but catalyzed access to NP. This suggests the increased belowground food availability in NP plots increased Na demand. Na and NP supply rates vary with climate, land use, and with inputs like urine. The co-limitation and catalysis of N and P by Na thus has the potential for predicting patterns of abundance and diversity across spatial scales.
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Affiliation(s)
- Michael Kaspari
- Graduate Program in EEB, Department of Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Karl A Roeder
- Graduate Program in EEB, Department of Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Brittany Benson
- Graduate Program in EEB, Department of Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Michael D Weiser
- Graduate Program in EEB, Department of Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Nathan J Sanders
- Rocky Mountain Biological Laboratory, PO Box 519, Crested Butte, Colorado, 81224, USA.,Center for Macroecology, Evolution, and Climate, Natural History Museum, University of Copenhagen, Copenhagen, 2100, Denmark
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35
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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36
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Abstract
Natural disturbances can occur stochastically with profound impacts on fauna and flora. Here we quantified the impact of a one in 100-yr flood on terrestrial invertebrate communities in south central Oklahoma. Before the flood, we observed 4,082 individuals from 92 species weighing a total of 18.61 g that belonged to compositionally different above or belowground communities. One year after the initial sampling period and 9 mo post-flood, we measured a 93% decrease in abundance, a 60% decrease in species richness, and a 64% decrease in biomass as well as increased compositional similarity between the above and belowground communities. Of the eight insect orders that were present before the flood, only the Coleoptera and Orthoptera increased immediately after the flood. Of these, only the Orthoptera remained at an elevated level across all post-flood sampling periods, specifically due to an increase in crickets (Orthoptera: Gryllidae). As we enter an era of global change, using natural perturbation experiments will improve our knowledge about the ecological processes that shape patterns of community assembly and biodiversity.
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Affiliation(s)
- Karl A Roeder
- Department of Biology, Graduate Program in Ecology and Evolutionary Biology, University of Oklahoma, Norman, OK
| | - Diane V Roeder
- Department of Agriculture, Biology and Health Sciences, Cameron University, Lawton, OK
| | - Michael Kaspari
- Department of Biology, Graduate Program in Ecology and Evolutionary Biology, University of Oklahoma, Norman, OK
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37
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Sheldon KS, Huey RB, Kaspari M, Sanders NJ. Fifty Years of Mountain Passes: A Perspective on Dan Janzen’s Classic Article. Am Nat 2018; 191:553-565. [DOI: 10.1086/697046] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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38
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Wright SJ, Turner BL, Yavitt JB, Harms KE, Kaspari M, Tanner EVJ, Bujan J, Griffin EA, Mayor JR, Pasquini SC, Sheldrake M, Garcia MN. Plant responses to fertilization experiments in lowland, species-rich, tropical forests. Ecology 2018; 99:1129-1138. [PMID: 29460277 DOI: 10.1002/ecy.2193] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 01/07/2018] [Accepted: 01/22/2018] [Indexed: 01/22/2023]
Abstract
We present a meta-analysis of plant responses to fertilization experiments conducted in lowland, species-rich, tropical forests. We also update a key result and present the first species-level analyses of tree growth rates for a 15-yr factorial nitrogen (N), phosphorus (P), and potassium (K) experiment conducted in central Panama. The update concerns community-level tree growth rates, which responded significantly to the addition of N and K together after 10 yr of fertilization but not after 15 yr. Our experimental soils are infertile for the region, and species whose regional distributions are strongly associated with low soil P availability dominate the local tree flora. Under these circumstances, we expect muted responses to fertilization, and we predicted species associated with low-P soils would respond most slowly. The data did not support this prediction, species-level tree growth responses to P addition were unrelated to species-level soil P associations. The meta-analysis demonstrated that nutrient limitation is widespread in lowland tropical forests and evaluated two directional hypotheses concerning plant responses to N addition and to P addition. The meta-analysis supported the hypothesis that tree (or biomass) growth rate responses to fertilization are weaker in old growth forests and stronger in secondary forests, where rapid biomass accumulation provides a nutrient sink. The meta-analysis found no support for the long-standing hypothesis that plant responses are stronger for P addition and weaker for N addition. We do not advocate discarding the latter hypothesis. There are only 14 fertilization experiments from lowland, species-rich, tropical forests, 13 of the 14 experiments added nutrients for five or fewer years, and responses vary widely among experiments. Potential fertilization responses should be muted when the species present are well adapted to nutrient-poor soils, as is the case in our experiment, and when pest pressure increases with fertilization, as it does in our experiment. The statistical power and especially the duration of fertilization experiments conducted in old growth, tropical forests might be insufficient to detect the slow, modest growth responses that are to be expected.
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Affiliation(s)
- S Joseph Wright
- Smithsonian Tropical Research Institute, Apartado 0843, Balboa, Panama
| | - Benjamin L Turner
- Smithsonian Tropical Research Institute, Apartado 0843, Balboa, Panama
| | - Joseph B Yavitt
- Department of Natural Resources, Cornell University, Ithaca, New York, 14853, USA
| | - Kyle E Harms
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - Michael Kaspari
- Department of Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Edmund V J Tanner
- Smithsonian Tropical Research Institute, Apartado 0843, Balboa, Panama.,Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, United Kingdom
| | - Jelena Bujan
- Department of Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Eric A Griffin
- Smithsonian Tropical Research Institute, Apartado 0843, Balboa, Panama.,Department of Biological Sciences, University of Pittsburgh, 4249 Fifth Avenue, Pittsburgh, Pennsylvania, 15260, USA.,Smithsonian Environmental Research Center, 647 Contees Wharf Road, Edgewater, Maryland, 21307, USA
| | - Jordan R Mayor
- Smithsonian Tropical Research Institute, Apartado 0843, Balboa, Panama.,ICF, P.O. Box 4495, Arcata, California, 95518, USA
| | - Sarah C Pasquini
- Department of Biological Sciences, University of Pittsburgh, 4249 Fifth Avenue, Pittsburgh, Pennsylvania, 15260, USA
| | - Merlin Sheldrake
- Smithsonian Tropical Research Institute, Apartado 0843, Balboa, Panama.,Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, United Kingdom
| | - Milton N Garcia
- Smithsonian Tropical Research Institute, Apartado 0843, Balboa, Panama
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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40
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Bujan J, Kaspari M. Nutrition modifies critical thermal maximum of a dominant canopy ant. J Insect Physiol 2017; 102:1-6. [PMID: 28830761 DOI: 10.1016/j.jinsphys.2017.08.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 08/13/2017] [Accepted: 08/17/2017] [Indexed: 06/07/2023]
Abstract
While adaptive responses to climate gradients are increasingly documented, little is known about how individuals alter their upper thermal tolerances. Long-term increases in dietary carbohydrates can elevate upper thermal tolerances in insects. We explored how the nutritional state of a Neotropical canopy ant governs its CTmax - the temperature at which individuals lose muscle control. We predicted that Azteca chartifex workers recently fed a carbohydrate-rich diet, such as honeydew and extrafloral nectar, would use that energy to increase their CTmax. Moreover, if a carbohydrate-rich diet increases CTmax, then we predicted that ants from colonies with high CTmaxs feed at a lower trophic level, and thus have a higher carbon:nitrogen ratio. We used A. chartifex colonies from a long-term fertilization experiment where phosphorus addition increased A. chartifex foraging activity with respect to controls. As foraging activity can be governed by resource availability, we first measured CTmax of field collected colonies. In freshly collected field colonies, CTmax was 2°C higher in control plots. This difference disappeared when ants were provided with only water for 10h. Ants were then provided with a 10% sucrose solution ad lib which increased CTmax by 5°C. We thus support the hypothesis that enhanced carbohydrate nutrition enables higher thermal tolerance, but this does not appear to be linked to colony trophic status, higher carbon:nitrogen ratios, or higher total body phosphorus. This short-term thermal plasticity linked to carbohydrate nutrition demonstrates the importance of ant diet in shaping their physiological traits. It is especially relevant to ant species that maintain high abundance by feeding on plant exudates. In a rapidly warming world, carbohydrate availability and use may represent a new element for predicting population and community responses of herbivorous insects.
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Affiliation(s)
- Jelena Bujan
- Department of Biology, Graduate Program in Ecology and Evolutionary Biology, University of Oklahoma, Norman, OK, USA.
| | - Michael Kaspari
- Department of Biology, Graduate Program in Ecology and Evolutionary Biology, University of Oklahoma, Norman, OK, USA; Smithsonian Tropical Research Institute, Balboa, Ancon, Panama
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41
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Kaspari M, Bujan J, Weiser MD, Ning D, Michaletz ST, Zhili H, Enquist BJ, Waide RB, Zhou J, Turner BL, Wright SJ. Biogeochemistry drives diversity in the prokaryotes, fungi, and invertebrates of a Panama forest. Ecology 2017; 98:2019-2028. [PMID: 28500769 DOI: 10.1002/ecy.1895] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Revised: 04/26/2017] [Accepted: 05/05/2017] [Indexed: 01/13/2023]
Abstract
Humans are both fertilizing the world and depleting its soils, decreasing the diversity of aquatic ecosystems and terrestrial plants in the process. We know less about how nutrients shape the abundance and diversity of the prokaryotes, fungi, and invertebrates of Earth's soils. Here we explore this question in the soils of a Panama forest subject to a 13-yr fertilization with factorial combinations of nitrogen (N), phosphorus (P), and potassium (K) and a separate micronutrient cocktail. We contrast three hypotheses linking biogeochemistry to abundance and diversity. Consistent with the Stress Hypothesis, adding N suppressed the abundance of invertebrates and the richness of all three groups of organisms by ca. 1 SD or more below controls. Nitrogen addition plots were 0.8 pH units more acidic with 18% more exchangeable aluminum, which is toxic to both prokaryotes and eukaryotes. These stress effects were frequently reversed, however, when N was added with P (for prokaryotes and invertebrates) and with added K (for fungi). Consistent with the Abundance Hypothesis, adding P generally increased prokaryote and invertebrate diversity, and adding K enhanced invertebrate diversity. Also consistent with the Abundance Hypothesis, increases in invertebrate abundance generated increases in richness. We found little evidence for the Competition Hypothesis: that single nutrients suppressed diversity by favoring a subset of high nutrient specialists, and that nutrient combinations suppressed diversity even more. Instead, combinations of nutrients, and especially the cation/micronutrient treatment, yielded the largest increases in richness in the two eukaryote groups. In sum, changes in soil biogeochemistry revealed a diversity of responses among the three dominant soil groups, positive synergies among nutrients, and-in contrast with terrestrial plants-the frequent enhancement of soil biodiversity.
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Affiliation(s)
- Michael Kaspari
- Department of Biology, Graduate Program in Ecology and Evolutionary Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA.,Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama
| | - Jelena Bujan
- Department of Biology, Graduate Program in Ecology and Evolutionary Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA.,Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama
| | - Michael D Weiser
- Department of Biology, Graduate Program in Ecology and Evolutionary Biology, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Daliang Ning
- Department of Botany and Microbiology, Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Sean T Michaletz
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, 85721, USA.,Earth and Environmental Sciences Division, Los Alamos National Laboratory, MS J495, Los Alamos, New Mexico, 87545, USA
| | - He Zhili
- Department of Botany and Microbiology, Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Brian J Enquist
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, 85721, USA.,Santa Fe Institute, Santa Fe, New Mexico, 87501, USA
| | - Robert B Waide
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, 87131, USA.,LTER Network Office, University of New Mexico, Albuquerque, New Mexico, 87131, USA
| | - Jizhong Zhou
- Department of Botany and Microbiology, Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, 73019, USA.,CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Benjamin L Turner
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama
| | - S Joseph Wright
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama
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42
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Gibb H, Dunn RR, Sanders NJ, Grossman BF, Photakis M, Abril S, Agosti D, Andersen AN, Angulo E, Armbrecht I, Arnan X, Baccaro FB, Bishop TR, Boulay R, Brühl C, Castracani C, Cerda X, Del Toro I, Delsinne T, Diaz M, Donoso DA, Ellison AM, Enriquez ML, Fayle TM, Feener DH, Fisher BL, Fisher RN, Fitzpatrick MC, Gómez C, Gotelli NJ, Gove A, Grasso DA, Groc S, Guenard B, Gunawardene N, Heterick B, Hoffmann B, Janda M, Jenkins C, Kaspari M, Klimes P, Lach L, Laeger T, Lattke J, Leponce M, Lessard JP, Longino J, Lucky A, Luke SH, Majer J, McGlynn TP, Menke S, Mezger D, Mori A, Moses J, Munyai TC, Pacheco R, Paknia O, Pearce-Duvet J, Pfeiffer M, Philpott SM, Resasco J, Retana J, Silva RR, Sorger MD, Souza J, Suarez A, Tista M, Vasconcelos HL, Vonshak M, Weiser MD, Yates M, Parr CL. A global database of ant species abundances. Ecology 2017; 98:883-884. [DOI: 10.1002/ecy.1682] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 11/22/2016] [Accepted: 11/29/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Heloise Gibb
- Department of Ecology, Environment and Evolution; La Trobe University; Melbourne 3086 Victoria Australia
| | - Rob R. Dunn
- Department of Applied Ecology; North Carolina State University; Raleigh North Carolina 27695 USA
- Center for Macroecology, Evolution, and Climate; Natural History Museum of Denmark; University of Copenhagen; Universitetsparken 15 DK-2100 Copenhagen Ø Denmark
| | - Nathan J. Sanders
- Center for Macroecology, Evolution, and Climate; Natural History Museum of Denmark; University of Copenhagen; Universitetsparken 15 DK-2100 Copenhagen Ø Denmark
| | - Blair F. Grossman
- Department of Ecology, Environment and Evolution; La Trobe University; Melbourne 3086 Victoria Australia
| | - Manoli Photakis
- Department of Ecology, Environment and Evolution; La Trobe University; Melbourne 3086 Victoria Australia
| | - Silvia Abril
- Department of Environmental Science; University of Girona; Montilivi Campus s/n 17071 Girona Spain
| | - Donat Agosti
- Naturhistorisches Museum Bern; Bernastrasse 15 3005 Bern Switzerland
| | - Alan N. Andersen
- CSIRO Ecosystem Sciences, Tropical Ecosystems Research Centre; PMB 44 Winnellie Northern Territory 0822 Australia
| | - Elena Angulo
- Departamento de Etología y Conservación de la Biodiversidad; Estación Biológica de Doñana; Avenida Americo Vespucio s/n (Isla de la Cartuja) Sevilla 41092 Spain
| | - Inge Armbrecht
- Facultad de Ciencias Naturales y Exactas; Universidad del Valle; Cali Colombia
| | - Xavier Arnan
- Departamento de Botânica; Universidade Federal Pernambuco; Avenida Prof Moraes Rego s/no Cidade Universitária Pernambuco Brazil
| | - Fabricio B. Baccaro
- Departamento de Biologia; Universidade Federal do Amazonas-UFAM; Manaus Amazonas Brazil
| | - Tom R. Bishop
- Department of Earth, Ocean and Ecological Sciences; University of Liverpool; Liverpool L69 3GP United Kingdom
- Department of Zoology and Entomology; Centre for Invasion Biology; University of Pretoria; Pretoria 0002 South Africa
| | - Raphaël Boulay
- Institut de Recherche sur la Biologie de l'Insecte et Département, d'Aménagement du Territoire Université; François Rabelais de Tours; Tours 37200 France
| | - Carsten Brühl
- Institute for Environmental Sciences; University Koblenz-Landau; Fortstraße 7 76829 Landau in der Pfalz Germany
| | - Cristina Castracani
- Department of Life Sciences; University of Parma; Parco Area delle Scienze 11/A Parma 43124 Italy
| | - Xim Cerda
- Departamento de Etología y Conservación de la Biodiversidad; Estación Biológica de Doñana; Avenida Americo Vespucio s/n (Isla de la Cartuja) Sevilla 41092 Spain
| | - Israel Del Toro
- Center for Macroecology, Evolution, and Climate; Natural History Museum of Denmark; University of Copenhagen; Universitetsparken 15 DK-2100 Copenhagen Ø Denmark
| | - Thibaut Delsinne
- Société d'Histoire Naturelle Alcide-d'Orbigny; 57 rue de Gergovie 63170 Aubière France
| | - Mireia Diaz
- Department of Environmental Science; University of Girona; Montilivi Campus s/n 17071 Girona Spain
| | - David A. Donoso
- Instituto de Ciencias Biológicas; Escuela Politécnica Nacional; Avenida Ladrón de Guevara E11253 Quito Ecuador
| | - Aaron M. Ellison
- Harvard Forest; Harvard University; 324 North Main Street Petersham Massachusetts 01366 USA
- Departments of Biology and Environmental Conservation; University of Massachusetts; Morrill Science Center and Holdsworth Hall, 611 North Pleasant Street Amherst Massachusetts 01003 USA
- Faculty of Arts, Business and Law; Tropical Forests and People Research Centre; University of the Sunshine Coast; 90 Sippy Downs Drive Sippy Downs Queensland 4556 Australia
| | - Martha L. Enriquez
- Department of Environmental Science; University of Girona; Montilivi Campus s/n 17071 Girona Spain
| | - Tom M. Fayle
- Institute of Entomology; Biology Centre of Academy of Sciences Czech Republic and Faculty of Science; University of South Bohemia; Branišovská 31 České Budějovice 370 05 Czech Republic
- Forest Ecology and Conservation Group; Imperial College London; Silwood Park Campus, Buckhurst Road Ascot SL5 7PY United Kingdom
| | - Donald H. Feener
- Department of Biology; University of Utah; Salt Lake City Utah 84112 USA
| | - Brian L. Fisher
- Entomology; California Academy of Sciences; San Francisco California USA
| | - Robert N. Fisher
- Western Ecological Research Center; U.S. Geological Survey; San Diego Field Station 4165 Spruance Road, Suite 200 San Diego California 92101 USA
| | - Matthew C. Fitzpatrick
- Appalachian Laboratory; University of Maryland Centre for Environmental Science; Frostburg Maryland 21532 USA
| | - Crisanto Gómez
- Department of Environmental Science; University of Girona; Montilivi Campus s/n 17071 Girona Spain
| | | | - Aaron Gove
- Astron Environmental Services; Perth Western Australia Australia
- Department of Environment and Agriculture; Curtin University; G.P.O. Box U1987 Perth Western Australia 6845 Australia
| | - Donato A. Grasso
- Department of Life Sciences; University of Parma; Parco Area delle Scienze 11/A Parma 43124 Italy
| | - Sarah Groc
- Instituto de Biologia; Universidade Federal de Uberlândia (UFU) Rua Ceara; Uberlândia Minas Gerais 38400-902 Brazil
| | - Benoit Guenard
- School of Biological Sciences; The University of Hong Kong; Pok Fu Lam Road Hong Kong China
| | - Nihara Gunawardene
- Department of Environment and Agriculture; Curtin University; G.P.O. Box U1987 Perth Western Australia 6845 Australia
| | - Brian Heterick
- Department of Environment and Agriculture; Curtin University; G.P.O. Box U1987 Perth Western Australia 6845 Australia
| | - Benjamin Hoffmann
- CSIRO Ecosystem Sciences, Tropical Ecosystems Research Centre; PMB 44 Winnellie Northern Territory 0822 Australia
| | - Milan Janda
- Institute of Entomology; Biology Centre of Academy of Sciences Czech Republic and Faculty of Science; University of South Bohemia; Branišovská 31 České Budějovice 370 05 Czech Republic
- Department of Biology; University of Guanajuato; Noria Alta sn. Guanajuato Mexico
| | - Clinton Jenkins
- IPÊ-Instituto de Pesquisas Ecológicas; Nazaré Paulista São Paulo 12960-000 Brazil
| | - Michael Kaspari
- Department of Biology; University of Oklahoma; 730 Van Vleet Oval, Room 314 Norman Oklahoma 73019 USA
| | - Petr Klimes
- Institute of Entomology; Biology Centre of Academy of Sciences Czech Republic and Faculty of Science; University of South Bohemia; Branišovská 31 České Budějovice 370 05 Czech Republic
- New Guinea Binatang Research Center; P.O. Box 604 Madang Papua New Guinea
| | - Lori Lach
- Centre for Tropical Biology and Climate Change; School of Marine and Tropical Biology; James Cook University; P.O. Box 6811 Cairns Queensland 4870 Australia
| | | | - John Lattke
- Departamento de Zoologia; Universidade Federal do Paraná; Caixa Postal 19020 81531-980 Curitiba Paraná Brazil
| | - Maurice Leponce
- Section of Biological Evaluation; Royal Belgian Institute of Natural Sciences; Rue Vautier, 29 Brussels 1000 Belgium
| | | | - John Longino
- Department of Biology; University of Utah; Salt Lake City Utah 84112 USA
| | - Andrea Lucky
- Entomology and Nematology Department; University of Florida; 970 Natural Area Drive Gainesville Florida 32611 USA
| | - Sarah H. Luke
- School of Biological Sciences; University of East Anglia; Norwich NR4 7TJ United Kingdom
- Department of Zoology; University of Cambridge; Downing Street Cambridge CB2 3EJ United Kingdom
| | - Jonathan Majer
- Department of Environment and Agriculture; Curtin University; G.P.O. Box U1987 Perth Western Australia 6845 Australia
- School of Plant Biology; The University of Western Australia; 35 Stirling Highway Crawley Western Australia 6009 Australia
| | - Terrence P. McGlynn
- Depatment of Biology; California State University Dominguez Hills; 1000 East Victoria Street Carson California 90747 USA
- Department of Entomology; Natural History Museum of Los Angeles County; Los Angeles California USA
| | - Sean Menke
- Department of Biology; Lake Forest College; 555 North Sheridan Road Lake Forest Illinois 60045 USA
| | - Dirk Mezger
- Division of Insects; Department of Zoology; Moreau Lab; Field Museum of Natural History; 1400 South Lake Shore Drive Chicago Illinois 60605 USA
| | - Alessandra Mori
- Department of Life Sciences; University of Parma; Parco Area delle Scienze 11/A Parma 43124 Italy
| | - Jimmy Moses
- Institute of Entomology; Biology Centre of Academy of Sciences Czech Republic and Faculty of Science; University of South Bohemia; Branišovská 31 České Budějovice 370 05 Czech Republic
- New Guinea Binatang Research Center; P.O. Box 604 Madang Papua New Guinea
| | - Thinandavha Caswell Munyai
- School of Life Sciences; College of Agriculture Engineering and Science; University of KwaZulu-Natal; Pietermaritzburg 3209 South Africa
| | - Renata Pacheco
- Instituto de Biologia; Universidade Federal de Uberlândia (UFU) Rua Ceara; Uberlândia Minas Gerais 38400-902 Brazil
| | - Omid Paknia
- Institute of Animal Ecology and Cell Biology; TiHo Hannover; Bünteweg 17d Hannover 30559 Germany
| | | | - Martin Pfeiffer
- Department of Ecology; National University of Mongolia; Baga Toiruu 47 P.O. Box 377 Ulaanbaatar 210646 Mongolia
| | - Stacy M. Philpott
- Environmental Studies Department; University of California; 1156 High Street Santa Cruz California 95060 USA
| | - Julian Resasco
- The Department of Ecology and Evolutionary Biology; University of Colorado; UCB 334 Boulder Colorado 80309 USA
| | - Javier Retana
- Universitat Autònoma Barcelona; Cerdanyola del Vallès 08193 Spain
| | - Rogerio R. Silva
- Coordenação de Ciências da Terra e Ecologia; Museu Paraense Emílio Goeldi; Belém Pará Brazil
| | - Magdalena D. Sorger
- Department of Applied Ecology; North Carolina State University; Raleigh North Carolina 27695 USA
| | - Jorge Souza
- Coordenação de Biodiversidade; National Institute of Amazonian Research; Manaus Amazonas Brazil
| | - Andrew Suarez
- Department of Entomology; University of Illinois, Urbana-Champaign; Urbana Illinois 61801 USA
| | - Melanie Tista
- Department of Tropical Ecology and Animal Biodiversity; University of Vienna; Rennweg 14 Vienna 1030 Austria
| | - Heraldo L. Vasconcelos
- Instituto de Biologia; Universidade Federal de Uberlândia (UFU) Rua Ceara; Uberlândia Minas Gerais 38400-902 Brazil
| | - Merav Vonshak
- Department of Biology; Stanford University; Stanford California 94305 USA
| | - Michael D. Weiser
- Department of Biology; University of Oklahoma; 730 Van Vleet Oval, Room 314 Norman Oklahoma 73019 USA
| | - Michelle Yates
- Centre for Behavioural and Physiological Ecology, Zoology; University of New England; Armidale New South Wales Australia
| | - Catherine L. Parr
- Department of Earth, Ocean and Ecological Sciences; University of Liverpool; Liverpool L69 3GP United Kingdom
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Lucas J, Bill B, Stevenson B, Kaspari M. The microbiome of the ant‐built home: the microbial communities of a tropical arboreal ant and its nest. Ecosphere 2017. [DOI: 10.1002/ecs2.1639] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Affiliation(s)
- Jane Lucas
- Department of Biology Graduate Program in Ecology and Evolutionary Biology University of Oklahoma Norman Oklahoma 73019 USA
| | - Brian Bill
- Department of Microbiology and Plant Biology Graduate Program in Ecology and Evolutionary Biology University of Oklahoma Norman Oklahoma 73019 USA
| | - Bradley Stevenson
- Department of Microbiology and Plant Biology Graduate Program in Ecology and Evolutionary Biology University of Oklahoma Norman Oklahoma 73019 USA
| | - Michael Kaspari
- Department of Biology Graduate Program in Ecology and Evolutionary Biology University of Oklahoma Norman Oklahoma 73019 USA
- Smithsonian Tropical Research Institute Apartado 2072 Balboa Panamá
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44
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Spicer ME, Stark AY, Adams BJ, Kneale R, Kaspari M, Yanoviak SP. Thermal constraints on foraging of tropical canopy ants. Oecologia 2017; 183:1007-1017. [PMID: 28132105 DOI: 10.1007/s00442-017-3825-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 01/19/2017] [Indexed: 10/20/2022]
Abstract
Small cursorial ectotherms risk overheating when foraging in the tropical forest canopy, where the surfaces of unshaded tree branches commonly exceed 50 °C. We quantified the heating and subsequent cooling rates of 11 common canopy ant species from Panama and tested the hypothesis that ant workers stop foraging at temperatures consistent with the prevention of overheating. We created hot experimental "sunflecks" on existing foraging trails of four ant species from different clades and spanning a broad range of body size, heating rate, and critical thermal maxima (CTmax). Different ant species exhibited very different heating rates in the lab, and these differences did not follow trends predicted by body size alone. Experiments with ant models showed that heating rates are strongly affected by color in addition to body size. Foraging workers of all species showed strong responses to heating and consistently abandoned focal sites between 36 and 44 °C. Atta colombica and Azteca trigona workers resumed foraging shortly after heat was removed, but Cephalotes atratus and Dolichoderus bispinosus workers continued to avoid the heated patch even after >5 min of cooling. Large foraging ants (C. atratus) responded slowly to developing thermal extremes, whereas small ants (A. trigona) evacuated sunflecks relatively quickly, and at lower estimated body temperatures than when revisiting previously heated patches. The results of this study provide the first field-based insight into how foraging ants respond behaviorally to the heterogeneous thermal landscape of the tropical forest canopy.
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Affiliation(s)
- Michelle Elise Spicer
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Alyssa Y Stark
- Department of Biology, University of Louisville, Louisville, KY, 40292, USA
| | - Benjamin J Adams
- Department of Biology, University of Louisville, Louisville, KY, 40292, USA
| | - Riley Kneale
- Department of Biology, University of Louisville, Louisville, KY, 40292, USA
| | - Michael Kaspari
- Department of Biology, University of Oklahoma, Norman, OK, 73019, USA.,Smithsonian Tropical Research Institute, Balboa, Republic of Panama
| | - Stephen P Yanoviak
- Department of Biology, University of Louisville, Louisville, KY, 40292, USA. .,Smithsonian Tropical Research Institute, Balboa, Republic of Panama.
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Roeder KA, Kaspari M. From cryptic herbivore to predator: stable isotopes reveal consistent variability in trophic levels in an ant population. Ecology 2017; 98:297-303. [DOI: 10.1002/ecy.1641] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Revised: 10/28/2016] [Accepted: 10/28/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Karl A. Roeder
- Department of Biology; Graduate Program in Ecology and Evolutionary Biology; University of Oklahoma; 730 Van Vleet Oval, Room 314 Norman Oklahoma 73019 USA
| | - Michael Kaspari
- Department of Biology; Graduate Program in Ecology and Evolutionary Biology; University of Oklahoma; 730 Van Vleet Oval, Room 314 Norman Oklahoma 73019 USA
- Smithsonian Tropical Research Institute; Balboa Panama
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Affiliation(s)
- Jelena Bujan
- Department of Biology Graduate Program in Ecology and Evolutionary Biology University of Oklahoma Norman Oklahoma 73019 USA
| | - S. Joseph Wright
- Smithsonian Tropical Research Institute Apartado 0843‐03092 Balboa Republic of Panama
| | - Michael Kaspari
- Department of Biology Graduate Program in Ecology and Evolutionary Biology University of Oklahoma Norman Oklahoma 73019 USA
- Smithsonian Tropical Research Institute Apartado 0843‐03092 Balboa Republic of Panama
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47
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Michaletz ST, Weiser MD, McDowell NG, Zhou J, Kaspari M, Helliker BR, Enquist BJ. Corrigendum: The energetic and carbon economic origins of leaf thermoregulation. Nat Plants 2016; 2:16147. [PMID: 27564422 DOI: 10.1038/nplants.2016.147] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
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Michaletz ST, Weiser MD, McDowell NG, Zhou J, Kaspari M, Helliker BR, Enquist BJ. The energetic and carbon economic origins of leaf thermoregulation. Nat Plants 2016; 2:16129. [PMID: 27548589 DOI: 10.1038/nplants.2016.129] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 07/27/2016] [Indexed: 05/12/2023]
Abstract
Leaf thermoregulation has been documented in a handful of studies, but the generality and origins of this pattern are unclear. We suggest that leaf thermoregulation is widespread in both space and time, and originates from the optimization of leaf traits to maximize leaf carbon gain across and within variable environments. Here we use global data for leaf temperatures, traits and photosynthesis to evaluate predictions from a novel theory of thermoregulation that synthesizes energy budget and carbon economics theories. Our results reveal that variation in leaf temperatures and physiological performance are tightly linked to leaf traits and carbon economics. The theory, parameterized with global averaged leaf traits and microclimate, predicts a moderate level of leaf thermoregulation across a broad air temperature gradient. These predictions are supported by independent data for diverse taxa spanning a global air temperature range of ∼60 °C. Moreover, our theory predicts that net carbon assimilation can be maximized by means of a trade-off between leaf thermal stability and photosynthetic stability. This prediction is supported by globally distributed data for leaf thermal and photosynthetic traits. Our results demonstrate that the temperatures of plant tissues, and not just air, are vital to developing more accurate Earth system models.
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Affiliation(s)
- Sean T Michaletz
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, MS J495, Los Alamos, New Mexico 87545, USA
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USA
| | - Michael D Weiser
- Department of Biology, EEB Graduate Program, University of Oklahoma, Norman, Oklahoma 73069, USA
| | - Nate G McDowell
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USA
| | - Jizhong Zhou
- Institute for Environmental Genomics, and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma 73019, USA
- State Key Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
- Earth Science Division, Lawrence Berkeley Laboratory, Berkeley, California 94270, USA
| | - Michael Kaspari
- Department of Biology, EEB Graduate Program, University of Oklahoma, Norman, Oklahoma 73069, USA
- Smithsonian Tropical Research Institute, Balboa, Republic of Panama
| | - Brent R Helliker
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Brian J Enquist
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USA
- The Santa Fe Institute, 1399 Hyde Park Rd, Santa Fe, New Mexico 87501, USA
- The iPlant Collaborative, Thomas W. Keating Bioresearch Building, 1657 East Helen Street, Tucson, Arizona 85721, USA
- Aspen Center for Environmental Studies, 100 Puppy Smith Street, Aspen, Colorado 81611, USA
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Bujan J, Yanoviak SP, Kaspari M. Desiccation resistance in tropical insects: causes and mechanisms underlying variability in a Panama ant community. Ecol Evol 2016; 6:6282-91. [PMID: 27648242 PMCID: PMC5016648 DOI: 10.1002/ece3.2355] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 07/05/2016] [Accepted: 07/11/2016] [Indexed: 02/04/2023] Open
Abstract
Desiccation resistance, the ability of an organism to reduce water loss, is an essential trait in arid habitats. Drought frequency in tropical regions is predicted to increase with climate change, and small ectotherms are often under a strong desiccation risk. We tested hypotheses regarding the underexplored desiccation potential of tropical insects. We measured desiccation resistance in 82 ant species from a Panama rainforest by recording the time ants can survive desiccation stress. Species' desiccation resistance ranged from 0.7 h to 97.9 h. We tested the desiccation adaptation hypothesis, which predicts higher desiccation resistance in habitats with higher vapor pressure deficit (VPD) - the drying power of the air. In a Panama rainforest, canopy microclimates averaged a VPD of 0.43 kPa, compared to a VPD of 0.05 kPa in the understory. Canopy ants averaged desiccation resistances 2.8 times higher than the understory ants. We tested a number of mechanisms to account for desiccation resistance. Smaller insects should desiccate faster given their higher surface area to volume ratio. Desiccation resistance increased with ant mass, and canopy ants averaged 16% heavier than the understory ants. A second way to increase desiccation resistance is to carry more water. Water content was on average 2.5% higher in canopy ants, but total water content was not a good predictor of ant desiccation resistance or critical thermal maximum (CT max), a measure of an ant's thermal tolerance. In canopy ants, desiccation resistance and CT max were inversely related, suggesting a tradeoff, while the two were positively correlated in understory ants. This is the first community level test of desiccation adaptation hypothesis in tropical insects. Tropical forests do contain desiccation-resistant species, and while we cannot predict those simply based on their body size, high levels of desiccation resistance are always associated with the tropical canopy.
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Affiliation(s)
- Jelena Bujan
- Department of Biology Graduate Program in Ecology and Evolutionary Biology University of Oklahoma Norman Oklahoma
| | - Stephen P Yanoviak
- Department of Biology University of Louisville Louisville Kentucky; Smithsonian Tropical Research Institute Balboa Republic of Panama
| | - Michael Kaspari
- Department of Biology Graduate Program in Ecology and Evolutionary Biology University of Oklahoma Norman Oklahoma; Smithsonian Tropical Research Institute Balboa Republic of Panama
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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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