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Cease AJ. How Nutrients Mediate the Impacts of Global Change on Locust Outbreaks. ANNUAL REVIEW OF ENTOMOLOGY 2024; 69:527-550. [PMID: 38270985 DOI: 10.1146/annurev-ento-120220-110415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2024]
Abstract
Locusts are grasshoppers that can migrate en masse and devastate food security. Plant nutrient content is a key variable influencing population dynamics, but the relationship is not straightforward. For an herbivore, plant quality depends not only on the balance of nutrients and antinutrients in plant tissues, which is influenced by land use and climate change, but also on the nutritional state and demands of the herbivore, as well as its capacity to extract nutrients from host plants. In contrast to the concept of a positive relationship between nitrogen or protein concentration and herbivore performance, a five-decade review of lab and field studies indicates that equating plant N to plant quality is misleading because grasshoppers respond negatively or neutrally to increasing plant N just as often as they respond positively. For locusts specifically, low-N environments are actually beneficial because they supply high energy rates that support migration. Therefore, intensive land use, such as continuous grazing or cropping, and elevated ambient CO2 levels that decrease the protein:carbohydrate ratios of plants are predicted to broadly promote locust outbreaks.
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Affiliation(s)
- Arianne J Cease
- School of Sustainability, School of Life Sciences, and Global Locust Initiative, Arizona State University, Tempe, Arizona, USA;
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2
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Mohanbabu N, Veldhuis MP, Jung D, Ritchie ME. Integrating defense and leaf economic spectrum traits in a tropical savanna plant. FRONTIERS IN PLANT SCIENCE 2023; 14:1185616. [PMID: 37342149 PMCID: PMC10277734 DOI: 10.3389/fpls.2023.1185616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 05/22/2023] [Indexed: 06/22/2023]
Abstract
Introduction Allocation to plant defense traits likely depends on resource supply, herbivory, and other plant functional traits such as the leaf economic spectrum (LES) traits. Yet, attempts to integrate defense and resource acquisitive traits remain elusive. Methods We assessed intraspecific covariation between different defense and LES traits in a widely distributed tropical savanna herb, Solanum incanum, a unique model species for studying allocations to physical, chemical, and structural defenses to mammalian herbivory. Results We found that in a multivariate trait space, the structural defenses - lignin and cellulose - were positively related to the resource conservative traits - low SLA and low leaf N. Phenolic content, a chemical defense, was positively associated with resource acquisitive traits - high SLA and high leaf N - while also being associated with an independent third component axis. Both principal components 1 and 3 were not associated with resource supply and herbivory intensity. In contrast, spine density - a physical defense - was orthogonal to the LES axis and positively associated with soil P and herbivory intensity. Discussion These results suggest a hypothesized "pyramid" of trade-offs in allocation to defense along the LES and herbivory intensity axes. Therefore, future attempts to integrate defense traits with the broader plant functional trait framework, such as the LES, needs a multifaceted approach that accounts for unique influences of resource acquisitive traits and herbivory risk.
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Affiliation(s)
- Neha Mohanbabu
- Department of Biology, Syracuse University, Syracuse, NY, United States
| | - Michiel P. Veldhuis
- Institute of Environmental Sciences, Universiteit Leiden, Leiden, The Netherlands
| | - Dana Jung
- Department of Biology, Syracuse University, Syracuse, NY, United States
| | - Mark E. Ritchie
- Department of Biology, Syracuse University, Syracuse, NY, United States
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3
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Svenningsen CS, Bowler DE, Hecker S, Bladt J, Grescho V, Dam NM, Dauber J, Eichenberg D, Ejrnæs R, Fløjgaard C, Frenzel M, Frøslev TG, Hansen AJ, Heilmann‐Clausen J, Huang Y, Larsen JC, Menger J, Nayan NLBM, Pedersen LB, Richter A, Dunn RR, Tøttrup AP, Bonn A. Flying insect biomass is negatively associated with urban cover in surrounding landscapes. DIVERS DISTRIB 2022. [DOI: 10.1111/ddi.13532] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
| | - Diana E. Bowler
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Leipzig Germany
- Friedrich Schiller University Jena Institute of Biodiversity Jena Germany
- Department of Ecosystem Services Helmholtz Centre for Environmental Research – UFZ Leipzig Germany
| | - Susanne Hecker
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Leipzig Germany
- Department of Ecosystem Services Helmholtz Centre for Environmental Research – UFZ Leipzig Germany
| | - Jesper Bladt
- Department of Bioscience – Biodiversity and Conservation Aarhus University Aarhus Denmark
| | - Volker Grescho
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Leipzig Germany
- Department of Ecosystem Services Helmholtz Centre for Environmental Research – UFZ Leipzig Germany
| | - Nicole M. Dam
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Leipzig Germany
- Friedrich Schiller University Jena Institute of Biodiversity Jena Germany
| | - Jens Dauber
- Thünen‐Institute of Biodiversity Braunschweig Germany
| | - David Eichenberg
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Leipzig Germany
- Department of Ecosystem Services Helmholtz Centre for Environmental Research – UFZ Leipzig Germany
| | - Rasmus Ejrnæs
- Department of Bioscience – Biodiversity and Conservation Aarhus University Aarhus Denmark
| | - Camilla Fløjgaard
- Department of Bioscience – Biodiversity and Conservation Aarhus University Aarhus Denmark
| | - Mark Frenzel
- Department of Community Ecology Helmholtz Centre for Environmental Research – UFZ Halle Germany
| | - Tobias G. Frøslev
- Centre for GeoGenetics GLOBE Institute University of Copenhagen Copenhagen Denmark
| | - Anders J. Hansen
- Centre for GeoGenetics GLOBE Institute University of Copenhagen Copenhagen Denmark
| | - Jacob Heilmann‐Clausen
- Centre for Macroecology, Evolution and Climate GLOBE Institute University of Copenhagen Copenhagen Denmark
| | - Yuanyuan Huang
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Leipzig Germany
- Department of Ecosystem Services Helmholtz Centre for Environmental Research – UFZ Leipzig Germany
| | - Jonas C. Larsen
- Natural History Museum of Denmark University of Copenhagen Copenhagen Denmark
| | - Juliana Menger
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Leipzig Germany
- Department of Ecosystem Services Helmholtz Centre for Environmental Research – UFZ Leipzig Germany
- Coordenação de Biodiversidade Instituto Nacional de Pesquisas da Amazônia Manaus Brazil
| | - Nur L. B. M. Nayan
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Leipzig Germany
- Department of Ecosystem Services Helmholtz Centre for Environmental Research – UFZ Leipzig Germany
| | - Lene B. Pedersen
- Natural History Museum of Denmark University of Copenhagen Copenhagen Denmark
| | - Anett Richter
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Leipzig Germany
- Department of Ecosystem Services Helmholtz Centre for Environmental Research – UFZ Leipzig Germany
- Thünen‐Institute of Biodiversity Braunschweig Germany
| | - Robert R. Dunn
- Natural History Museum of Denmark University of Copenhagen Copenhagen Denmark
- Department of Applied Ecology North Carolina State University Raleigh North Carolina USA
| | - Anders P. Tøttrup
- Natural History Museum of Denmark University of Copenhagen Copenhagen Denmark
| | - Aletta Bonn
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Leipzig Germany
- Friedrich Schiller University Jena Institute of Biodiversity Jena Germany
- Department of Ecosystem Services Helmholtz Centre for Environmental Research – UFZ Leipzig Germany
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4
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Easterday CA, Kendig AE, Lacroix C, Seabloom EW, Borer ET. Long-term nitrogen enrichment mediates the effects of nitrogen supply and co-inoculation on a viral pathogen. Ecol Evol 2022; 12:e8450. [PMID: 35136545 PMCID: PMC8809429 DOI: 10.1002/ece3.8450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 11/02/2021] [Accepted: 11/05/2021] [Indexed: 11/12/2022] Open
Abstract
Host nutrient supply can mediate host-pathogen and pathogen-pathogen interactions. In terrestrial systems, plant nutrient supply is mediated by soil microbes, suggesting a potential role of soil microbes in plant diseases beyond soil-borne pathogens and induced plant defenses. Long-term nitrogen (N) enrichment can shift pathogenic and nonpathogenic soil microbial community composition and function, but it is unclear if these shifts affect plant-pathogen and pathogen-pathogen interactions. In a growth chamber experiment, we tested the effect of long-term N enrichment on infection by Barley Yellow Dwarf Virus (BYDV-PAV) and Cereal Yellow Dwarf Virus (CYDV-RPV), aphid-vectored RNA viruses, in a grass host. We inoculated sterilized growing medium with soil collected from a long-term N enrichment experiment (ambient, low, and high N soil treatments) to isolate effects mediated by the soil microbial community. We crossed soil treatments with a N supply treatment (low, high) and virus inoculation treatment (mock-, singly-, and co-inoculated) to evaluate the effects of long-term N enrichment on plant-pathogen and pathogen-pathogen interactions, as mediated by N availability. We measured the proportion of plants infected (i.e., incidence), plant biomass, and leaf chlorophyll content. BYDV-PAV incidence (0.96) declined with low N soil (to 0.46), high N supply (to 0.61), and co-inoculation (to 0.32). Low N soil mediated the effect of N supply on BYDV-PAV: instead of N supply reducing BYDV-PAV incidence, the incidence increased. Additionally, ambient and low N soil ameliorated the negative effect of co-inoculation on BYDV-PAV incidence. BYDV-PAV infection only reduced chlorophyll when plants were grown with low N supply and ambient N soil. There were no significant effects of long-term N soil on CYDV-RPV incidence. Soil inoculant with different levels of long-term N enrichment had different effects on host-pathogen and pathogen-pathogen interactions, suggesting that shifts in soil microbial communities with long-term N enrichment may mediate disease dynamics.
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Affiliation(s)
- Casey A. Easterday
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMinnesotaUSA
- Present address:
Carlson School of ManagementUniversity of MinnesotaMinneapolisMinnesotaUSA
| | - Amy E. Kendig
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMinnesotaUSA
| | - Christelle Lacroix
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMinnesotaUSA
- Present address:
Pathologie VégétaleINRAEMontfavetFrance
| | - Eric W. Seabloom
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMinnesotaUSA
| | - Elizabeth T. Borer
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMinnesotaUSA
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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] [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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Kaspari M. The seventh macronutrient: how sodium shortfall ramifies through populations, food webs and ecosystems. Ecol Lett 2020; 23:1153-1168. [PMID: 32380580 DOI: 10.1111/ele.13517] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 01/28/2020] [Accepted: 03/17/2020] [Indexed: 11/27/2022]
Abstract
Of the 25 elements required to build most organisms, sodium has a unique set of characteristics that ramify through terrestrial ecology. In plants, sodium is found in low concentrations and has little metabolic function; in plant consumers, particularly animals, sodium is essential to running costly Na-K ATPases. Here I synthesise a diverse literature from physiology, agronomy and ecology, towards identifying sodium's place as the '7th macronutrient', one whose shortfall targets two trophic levels - herbivores and detritivores. I propose that sodium also plays a central, though unheralded role in herbivore digestion, via its importance to maintaining microbiomes and denaturing tannins. I highlight how sodium availability is a key determinant of consumer abundance and the geography of herbivory and detritivory. And I propose a re-appraisal of the assumption that, because sodium is metabolically unimportant to most plants, it is of little use. Instead, I suggest that sodium's critical role in limiting herbivore performance makes it a commodity used by plants to manipulate their herbivores and mutualists, and by consumers like bison and elephants to generate grazing lawns: dependable sources of sodium.
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Affiliation(s)
- Michael Kaspari
- Geographical Ecology Group, Department of Biology, University of Oklahoma, Norman, OK, USA
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7
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Ma Y, Bao H, Bencini R, Raubenheimer D, Dou H, Liu H, Wang S, Jiang G. Macro-Nutritional Adaptive Strategies of Moose ( Alces alces) Related to Population Density. Animals (Basel) 2019; 10:ani10010073. [PMID: 31906149 PMCID: PMC7022907 DOI: 10.3390/ani10010073] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 12/13/2019] [Accepted: 12/21/2019] [Indexed: 11/16/2022] Open
Abstract
The distribution area of moose in China has been shrinking back toward the north and northeast because of climate change and human disturbance, and the population number has been declining. Between 2011 and 2015, we studied moose at six sites in the northeast of China during the snowy seasons. We collected fecal samples and plant samples that were used to estimate population densities for moose, as well as their macro-nutrient selection. Out of a total of 257 fecal samples collected at six sites, we identified a total of 120 individual moose (57 females and 63 males). The population density (moose/km2 ± SE) was highest at Hanma with 0.305 ± 0.064 moose/km2 and lowest at Meitian with only 0.028 ± 0.013 moose/km2. Forage availability was different among sites, with the lowest availability at Mohe (58.17 number/20 m2) and highest was Zhanhe (250.44 number/20 m2). Moose at Zhanhe, Hanma, and Nanwenghe had a balanced diet with higher N:C (1:7), while at Meitian, Shuanghe and Mohe the N:C was 1:8. Our results indicate that the southern areas had low forage quality and quantity and this may be the reason for the distribution of the population of moose shrinking northward.
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Affiliation(s)
- Yingjie Ma
- Feline Research Center of Chinese State Forestry Administration, College of Wildlife and Protected Areas, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China; (Y.M.); (H.B.); (S.W.)
- Key Lab of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, 1-5 Beichenxi Road, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Heng Bao
- Feline Research Center of Chinese State Forestry Administration, College of Wildlife and Protected Areas, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China; (Y.M.); (H.B.); (S.W.)
| | - Roberta Bencini
- School of Agriculture and Environment, The University of Western Australia, 35 Stirling Highway, Perth 6009, Australia;
| | - David Raubenheimer
- Charles Perkins Centre and School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia;
| | - Hongliang Dou
- College of Animal Science and Technology, Jinlin Agricultural University, Changchun 130118, China;
| | - Hui Liu
- Institute of Tropical Agriculture and Forestry, Hainan University, No. 58, Renmin Avenue, Haikou 570228, China;
| | - Sirui Wang
- Feline Research Center of Chinese State Forestry Administration, College of Wildlife and Protected Areas, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China; (Y.M.); (H.B.); (S.W.)
| | - Guangshun Jiang
- Feline Research Center of Chinese State Forestry Administration, College of Wildlife and Protected Areas, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China; (Y.M.); (H.B.); (S.W.)
- Correspondence:
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8
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Liu M, Gong J, Li Y, Li X, Yang B, Zhang Z, Yang L, Hou X. Growth-defense trade-off regulated by hormones in grass plants growing under different grazing intensities. PHYSIOLOGIA PLANTARUM 2019; 166:553-569. [PMID: 30091152 DOI: 10.1111/ppl.12802] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 07/08/2018] [Accepted: 07/11/2018] [Indexed: 06/08/2023]
Abstract
Herbivory creates conflicts between a plant's need to allocate resources for growth and defense. It is not yet clear how plants rebalance resource utilization between growth and defense in response to increasing grazing intensity. We measured characteristics of the primary and secondary metabolism of Leymus chinensis at five levels of grazing intensity (control, light, moderate, heavy and extremely heavy). Furthermore, we evaluated hormone signaling by quantifying the impact of key hormones on plant growth and defense. Under light grazing intensity, indole-3-acetic acid and jasmonates appeared to promote the growth of L. chinensis through a high photosynthetic rate, high water-use efficiency and high soluble protein contents, whereas abscisic acid decreased these properties. Under moderate grazing intensity, L. chinensis had a low photosynthetic capacity but greater production of secondary metabolites (tannins, total flavonoids and total phenols), possibly induced by salicylic acid. When the grazing pressure further intensified, L. chinensis translocated more carbohydrates to its roots in order to survive and regrow. Leymus chinensis therefore exhibited a trade-off between growth and defense in order to survive and reproduce under herbivory. Plants developed different mechanisms to enhance their grazing tolerance by means of hormonal regulation.
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Affiliation(s)
- Min Liu
- Key Laboratory of Surface Processes and Resource Ecology, College of Resources Science and Technology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| | - Jirui Gong
- Key Laboratory of Surface Processes and Resource Ecology, College of Resources Science and Technology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| | - Ying Li
- Key Laboratory of Surface Processes and Resource Ecology, College of Resources Science and Technology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| | - Xiaobing Li
- Key Laboratory of Surface Processes and Resource Ecology, College of Resources Science and Technology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| | - Bo Yang
- Key Laboratory of Surface Processes and Resource Ecology, College of Resources Science and Technology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| | - Zihe Zhang
- Key Laboratory of Surface Processes and Resource Ecology, College of Resources Science and Technology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| | - Lili Yang
- Key Laboratory of Surface Processes and Resource Ecology, College of Resources Science and Technology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| | - Xiangyang Hou
- Grassland Research Institute of Chinese Academy of Agricultural Science, Hohhot 010021, China
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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] [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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10
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Verschut TA, Hambäck PA. A random survival forest illustrates the importance of natural enemies compared to host plant quality on leaf beetle survival rates. BMC Ecol 2018; 18:33. [PMID: 30200936 PMCID: PMC6131828 DOI: 10.1186/s12898-018-0187-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 08/31/2018] [Indexed: 11/11/2022] Open
Abstract
Background Wetlands are habitats where variation in soil moisture content and associated environmental conditions can strongly affect the survival of herbivorous insects by changing host plant quality and natural enemy densities. In this study, we combined natural enemy exclusion experiments with random survival forest analyses to study the importance of local variation in host plant quality and predation by natural enemies on the egg and larval survival of the leaf beetle Galerucella sagittariae along a soil moisture gradient. Results Our results showed that the exclusion of natural enemies substantially increased the survival probability of G. sagittariae eggs and larvae. Interestingly, the egg survival probability decreased with soil moisture content, while the larval survival probability instead increased with soil moisture content. For both the egg and larval survival, we found that host plant height, the number of eggs or larvae, and vegetation height explained more of the variation than the soil moisture gradient by itself. Moreover, host plant quality related variables, such as leaf nitrogen, carbon and phosphorus content did not influence the survival of G. sagittariae eggs and larvae. Conclusion Our results suggest that the soil moisture content is not an overarching factor that determines the interplay between factors related to host plant quality and factors relating to natural enemies on the survival of G. sagittariae in different microhabitats. Moreover, the natural enemy exclusion experiments and the random survival forest analysis suggest that natural enemies have a stronger indirect impact on the survival of G. sagittariae offspring than host plant quality. Electronic supplementary material The online version of this article (10.1186/s12898-018-0187-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Thomas A Verschut
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91, Stockholm, Sweden.
| | - Peter A Hambäck
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91, Stockholm, Sweden
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11
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Robinson ML, Strauss SY. Cascading effects of soil type on assemblage size and structure in a diverse herbivore community. Ecology 2018; 99:1866-1877. [PMID: 29846941 DOI: 10.1002/ecy.2406] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 04/16/2018] [Accepted: 05/14/2018] [Indexed: 11/07/2022]
Abstract
Soil type is understudied as a driver of herbivore community size and structure across host plants. This study extends predictions of resource availability hypotheses to understand how soil types of different resource levels alter plant resistance and structure of herbivore assemblages. In this 2-yr study we use seven dominant chaparral shrub species that grow across a natural mosaic of low and high resource soils to explore effects of soil type on plant resistance, and relate these soil-based differences in resistance to the abundance and diversity of the larval lepidopteran community. We show that growing on low-resource soils increases plant resistance, as measured by herbivore performance, both within and across host plant species, and that resistance may be driven by variation in plant nutritive and defensive traits. We then show that more resistant plants on low-resource soils host less abundant and less diverse herbivore assemblages across a natural soil mosaic in the field.
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Affiliation(s)
- Moria L Robinson
- Center for Population Biology, University of California, Davis, 2320 Storer Hall, One Shields Avenue, Davis, California, 95616, USA
| | - Sharon Y Strauss
- Center for Population Biology, University of California, Davis, 2320 Storer Hall, One Shields Avenue, Davis, California, 95616, USA
- Department of Evolution and Ecology, University of California, Davis, 2320 Storer Hall, One Shields Avenue, Davis, California, 95616, USA
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12
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Chen C, Biere A, Gols R, Halfwerk W, van Oers K, Harvey JA. Responses of insect herbivores and their food plants to wind exposure and the importance of predation risk. J Anim Ecol 2018; 87:1046-1057. [PMID: 29672852 DOI: 10.1111/1365-2656.12835] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 03/21/2018] [Indexed: 11/30/2022]
Abstract
Wind is an important abiotic factor that influences an array of biological processes, but it is rarely considered in studies on plant-herbivore interactions. Here, we tested whether wind exposure could directly or indirectly affect the performance of two insect herbivores, Plutella xylostella and Pieris brassicae, feeding on Brassica nigra plants. In a greenhouse study using a factorial design, B. nigra plants were exposed to different wind regimes generated by fans before and after caterpillars were introduced on plants in an attempt to separate the effects of direct and indirect wind exposure on herbivores. Wind exposure delayed flowering, decreased plant height and increased leaf concentrations of amino acids and glucosinolates. Plant-mediated effects of wind on herbivores, that is effects of exposure of plants to wind prior to herbivore feeding, were generally small. However, development time of both herbivores was extended and adult body mass of P. xylostella was reduced when they were directly exposed to wind. By contrast, wind-exposed adult P. brassicae butterflies were significantly larger, revealing a trade-off between development time and adult size. Based on these results, we conducted a behavioural experiment to study preference by an avian predator, the great tit (Parus major) for last instar P. brassicae caterpillars on plants that were exposed to either control (no wind) or wind (fan-exposed) treatments. Tits captured significantly more caterpillars on still than on wind-exposed plants. Our results suggest that P. brassicae caterpillars are able to perceive the abiotic environment and to trade off the costs of extended development time against the benefits of increased size depending on the perceived risk of predation mediated by wind exposure. Such adaptive phenotypic plasticity in insects has not yet been described in response to wind exposure.
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Affiliation(s)
- Cong Chen
- Department of Terrestrial Ecology, Netherlands Institute of Ecology, Wageningen, The Netherlands
| | - Arjen Biere
- Department of Terrestrial Ecology, Netherlands Institute of Ecology, Wageningen, The Netherlands
| | - Rieta Gols
- Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands
| | - Wouter Halfwerk
- Department of Ecological Science, Section Animal Ecology, VU University Amsterdam, Amsterdam, The Netherlands
| | - Kees van Oers
- Department of Animal Ecology, Netherlands Institute of Ecology, Wageningen, The Netherlands
| | - Jeffrey A Harvey
- Department of Terrestrial Ecology, Netherlands Institute of Ecology, Wageningen, The Netherlands.,Department of Ecological Science, Section Animal Ecology, VU University Amsterdam, Amsterdam, The Netherlands
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13
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Liu Y, Ma G, Zan Z, Chen A, Miao Y, Wang D, Miao R. Effects of nitrogen addition and mowing on rodent damage in an Inner Mongolian steppe. Ecol Evol 2018; 8:3919-3926. [PMID: 29721268 PMCID: PMC5916279 DOI: 10.1002/ece3.3949] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 01/27/2018] [Accepted: 01/30/2018] [Indexed: 11/28/2022] Open
Abstract
Rodent damage is a serious threat to sustainable management of grassland. The effects of nitrogen (N) deposition and grassland management on rodent damage have been scarcely studied. Here, we reported the effects of 2 years of N addition and mowing on burrow density and damage area of Citellus dauricus in a semiarid steppe in Inner Mongolia. N addition significantly aggravated, while mowing alleviated rodent damage in the grassland under study. Burrow density and damage area increased 2.8‐fold and 4.7‐fold, in N addition plots compared to the ambient N addition treatment, respectively. Conversely, mowing decreased burrow density and damage area by 75.9% and 14.5%, respectively, compared to no mowing plots. Observed changes in rodent damage were mainly due to variations in plant community cover, height, and aboveground net primary productivity. Our findings demonstrate that N addition and mowing can affect the rodent density and activity in grassland, suggesting that the effects of a changing atmospheric composition and land use on rodent damage must be considered in order to achieve better grassland management.
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Affiliation(s)
- Yinzhan Liu
- International Joint Research Laboratory for Global Change Ecology State Key Laboratory of Cotton Biology School of Life Sciences Henan University Kaifeng Henan China
| | - Gaigai Ma
- International Joint Research Laboratory for Global Change Ecology State Key Laboratory of Cotton Biology School of Life Sciences Henan University Kaifeng Henan China
| | - Zhiman Zan
- Agricultural Schools Henan University of Science and Technology Luoyang China
| | - Anqun Chen
- International Joint Research Laboratory for Global Change Ecology State Key Laboratory of Cotton Biology School of Life Sciences Henan University Kaifeng Henan China
| | - Yuan Miao
- International Joint Research Laboratory for Global Change Ecology State Key Laboratory of Cotton Biology School of Life Sciences Henan University Kaifeng Henan China
| | - Dong Wang
- International Joint Research Laboratory for Global Change Ecology State Key Laboratory of Cotton Biology School of Life Sciences Henan University Kaifeng Henan China
| | - Renhui Miao
- International Joint Research Laboratory for Global Change Ecology State Key Laboratory of Cotton Biology School of Life Sciences Henan University Kaifeng Henan China
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14
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Does urbanization explain differences in interactions between an insect herbivore and its natural enemies and mutualists? Urban Ecosyst 2018. [DOI: 10.1007/s11252-017-0727-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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15
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Grainger TN, Gilbert B. Multi-scale responses to warming in an experimental insect metacommunity. GLOBAL CHANGE BIOLOGY 2017; 23:5151-5163. [PMID: 28556493 DOI: 10.1111/gcb.13777] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 05/22/2017] [Indexed: 05/24/2023]
Abstract
In metacommunities, diversity is the product of species interactions at the local scale and dispersal between habitat patches at the regional scale. Although warming can alter both species interactions and dispersal, the combined effects of warming on these two processes remains uncertain. To determine the independent and interactive effects of warming-induced changes to local species interactions and dispersal, we constructed experimental metacommunities consisting of enclosed milkweed patches seeded with five herbivorous milkweed specialist insect species. We treated metacommunities with two levels of warming (unwarmed and warmed) and three levels of connectivity (isolated, low connectivity, high connectivity). Based on metabolic theory, we predicted that if plant resources were limited, warming would accelerate resource drawdown, causing local insect declines and increasing both insect dispersal and the importance of connectivity to neighboring patches for insect persistence. Conversely, given abundant resources, warming could have positive local effects on insects, and the risk of traversing a corridor to reach a neighboring patch could outweigh the benefits of additional resources. We found support for the latter scenario. Neither resource drawdown nor the weak insect-insect associations in our system were affected by warming, and most insect species did better locally in warmed conditions and had dispersal responses that were unchanged or indirectly affected by warming. Dispersal across the matrix posed a species-specific risk that led to declines in two species in connected metacommunities. Combined, this scaled up to cause an interactive effect of warming and connectivity on diversity, with unwarmed metacommunities with low connectivity incurring the most rapid declines in diversity. Overall, this study demonstrates the importance of integrating the complex outcomes of species interactions and spatial structure in understanding community response to climate change.
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Affiliation(s)
- Tess Nahanni Grainger
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
| | - Benjamin Gilbert
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
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16
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Laws AN, Joern A. Density mediates grasshopper performance in response to temperature manipulation and spider predation in tallgrass prairie. BULLETIN OF ENTOMOLOGICAL RESEARCH 2017; 107:261-267. [PMID: 27702418 DOI: 10.1017/s0007485316000894] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Species interactions are often context-dependent, where outcomes require an understanding of influences among multiple biotic and abiotic factors. However, it remains unclear how abiotic factors such as temperature combine with important biotic factors such as density-dependent food limitation and predation to influence species interactions. Using a native grassland - grasshopper - wolf spider model food chain in tallgrass prairie, we conducted a manipulative field experiment to examine how predator-prey interactions respond to manipulations of temperature, grasshopper density, and food chain length. We find that grasshopper performance responses to temperature and predator treatments were density dependent. At high densities, grasshopper survival decreased with increased temperature when no spiders were present. When spiders were present, grasshopper survival was reduced, and this effect was strongest in the cooled treatment. In contrast, grasshopper survival did not vary significantly with spider presence or among temperature treatments at low grasshopper densities. Our results indicate that context-dependent species interactions are common and highlight the importance of understanding how and when key biotic and abiotic factors combine to influence species interactions.
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Affiliation(s)
- A N Laws
- Division of Biology,Kansas State University,Manhattan, KS 66506,USA
| | - A Joern
- Division of Biology,Kansas State University,Manhattan, KS 66506,USA
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17
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Lacasella F, Marta S, Singh A, Stack Whitney K, Hamilton K, Townsend P, Kucharik CJ, Meehan TD, Gratton C. From pest data to abundance-based risk maps combining eco-physiological knowledge, weather, and habitat variability. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2017; 27:575-588. [PMID: 27859850 DOI: 10.1002/eap.1467] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 10/03/2016] [Accepted: 10/21/2016] [Indexed: 06/06/2023]
Abstract
Noxious species, i.e., crop pest or invasive alien species, are major threats to both natural and managed ecosystems. Invasive pests are of special importance, and knowledge about their distribution and abundance is fundamental to minimize economic losses and prioritize management activities. Occurrence models are a common tool used to identify suitable zones and map priority areas (i.e., risk maps) for noxious species management, although they provide a simplified description of species dynamics (i.e., no indication on species density). An alternative is to use abundance models, but translating abundance data into risk maps is often challenging. Here, we describe a general framework for generating abundance-based risk maps using multi-year pest data. We used an extensive data set of 3968 records collected between 2003 and 2013 in Wisconsin during annual surveys of soybean aphid (SBA), an exotic invasive pest in this region. By using an integrative approach, we modelled SBA responses to weather, seasonal, and habitat variability using generalized additive models (GAMs). Our models showed good to excellent performance in predicting SBA occurrence and abundance (TSS = 0.70, AUC = 0.92; R2 = 0.63). We found that temperature, precipitation, and growing degree days were the main drivers of SBA trends. In addition, a significant positive relationship between SBA abundance and the availability of overwintering habitats was observed. Our models showed aphid populations were also sensitive to thresholds associated with high and low temperatures, likely related to physiological tolerances of the insects. Finally, the resulting aphid predictions were integrated using a spatial prioritization algorithm ("Zonation") to produce an abundance-based risk map for the state of Wisconsin that emphasized the spatiotemporal consistency and magnitude of past infestation patterns. This abundance-based risk map can provide information on potential foci of pest outbreaks where scouting efforts and prophylactic measures should be concentrated. The approach we took is general, relatively simple, and can be applied to other species, habitats and geographical areas for which species abundance data and biotic and abiotic data are available.
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Affiliation(s)
- Federica Lacasella
- Department of Entomology, University of Wisconsin, Madison, Wisconsin, 53706, USA
| | - Silvio Marta
- Department of Entomology, University of Wisconsin, Madison, Wisconsin, 53706, USA
| | - Aditya Singh
- Department of Forest and Wildlife Ecology, University of Wisconsin, Madison, Wisconsin, 53706, USA
| | | | - Krista Hamilton
- Wisconsin Department of Agriculture, Trade and Consumer Protection, Madison, Wisconsin, 54601, USA
| | - Phil Townsend
- Department of Forest and Wildlife Ecology, University of Wisconsin, Madison, Wisconsin, 53706, USA
| | - Christopher J Kucharik
- Department of Agronomy and Nelson Institute Center for Sustainability and Global Change, University of Wisconsin, Madison, Wisconsin, 53706, USA
| | - Timothy D Meehan
- Department of Entomology, University of Wisconsin, Madison, Wisconsin, 53706, USA
| | - Claudio Gratton
- Department of Entomology, University of Wisconsin, Madison, Wisconsin, 53706, USA
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18
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Chisté MN, Mody K, Gossner MM, Simons NK, Köhler G, Weisser WW, Blüthgen N. Losers, winners, and opportunists: How grassland land‐use intensity affects orthopteran communities. Ecosphere 2016. [DOI: 10.1002/ecs2.1545] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Melanie N. Chisté
- Ecological Networks Research GroupDepartment of BiologyTechnische Universität Darmstadt Schnittspahnstraße 3 64287 Darmstadt Germany
| | - Karsten Mody
- Ecological Networks Research GroupDepartment of BiologyTechnische Universität Darmstadt Schnittspahnstraße 3 64287 Darmstadt Germany
| | - Martin M. Gossner
- Terrestrial Ecology Research GroupDepartment of Ecology and Ecosystem ManagementTechnische Universität München Hans‐Carl‐von‐Carlowitz‐Platz 2 85354 Freising‐Weihenstephan Germany
| | - Nadja K. Simons
- Terrestrial Ecology Research GroupDepartment of Ecology and Ecosystem ManagementTechnische Universität München Hans‐Carl‐von‐Carlowitz‐Platz 2 85354 Freising‐Weihenstephan Germany
| | - Günter Köhler
- Population Ecology Research GroupDepartment of EcologyFriedrich‐Schiller Universität Jena Dornburger Straße 159 07743 Jena Germany
| | - Wolfgang W. Weisser
- Terrestrial Ecology Research GroupDepartment of Ecology and Ecosystem ManagementTechnische Universität München Hans‐Carl‐von‐Carlowitz‐Platz 2 85354 Freising‐Weihenstephan Germany
| | - Nico Blüthgen
- Ecological Networks Research GroupDepartment of BiologyTechnische Universität Darmstadt Schnittspahnstraße 3 64287 Darmstadt Germany
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19
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Kaspari M, Powers JS. Biogeochemistry and Geographical Ecology: Embracing All Twenty-Five Elements Required to Build Organisms. Am Nat 2016; 188 Suppl 1:S62-73. [PMID: 27513911 DOI: 10.1086/687576] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Biogeochemistry is a key but relatively neglected part of the abiotic template that underlies ecology. The template has a geography, one that is increasingly being rearranged in this era of global change. Justus von Liebig's law of the minimum has played a useful role in focusing attention on biogeochemical regulation of populations, but given that ∼25+ elements are required to build organisms and that these organisms use and deplete nutrients in aggregates of communities and ecosystems, we make the case that it is time to move on. We review available models that suggest the many different mechanisms that give rise to multiple elements, or colimitation. We then review recent empirical data that show that rates of decomposition and primary productivity may be limited by multiple elements. In that light, given the tropics' high species diversity and generally more weathered soils, we predict that colimitation at community and ecosystem scales is more prevalent closer to the equator. We conclude with suggestions for how to move forward with experimental studies of colimitation.
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20
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Tabea T, Dirk S, Eva K. Effects of urbanization on direct and indirect interactions in a tri-trophic system. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2016; 26:664-675. [PMID: 27411241 DOI: 10.1890/14-1787] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
While effects of urbanization on species assemblages are receiving increasing attention, effects on ecological interactions remain largely unexplored. We investigated how urbanization influences the strength of direct and indirect trophic interactions in a tri- trophic system. In a field experiment including five cities and nearby farmed areas, we used potted Vicia faba plants and manipulated the presence of Megoura viciae aphids and that of naturally occurring aphid predators. When predators could access aphids, they reduced their abundance less in the urban than in the agricultural ecosystem. Compared to aphid abundance on plants without predator access, abundance on plants with predator access was 2.58 times lower in urban and 5.27 times lower in agricultural areas. This indicates that urbanization limited top-down control of aphids by predators. In both ecosystems, plant biomass was negatively affected by herbivores and positively affected by predators, but the positive indirect predator effect was weaker in cities. Compared to aphid-infested plants without predator access, plants with predator access were 1.89 times heavier in urban and 2.12 times heavier in agricultural areas. Surprisingly, differences between ecosystems regarding the indirect predator effect on plants were not explained by the differentially strong herbivore suppression. Instead, the urban environment limited plant biomass per se, thereby mitigating the scope of a positive predator effect. Our results show that urbanization can influence direct and indirect trophic interactions through effects on biotic top-down forces and on plant growth. In order to understand how urbanization affects biodiversity and ecosystem functioning, it is fundamental to not only consider species assemblages, but also species interactions.
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21
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Metcalfe DB, Crutsinger GM, Kumordzi BB, Wardle DA. Nutrient fluxes from insect herbivory increase during ecosystem retrogression in boreal forest. Ecology 2016; 97:124-32. [PMID: 27008782 DOI: 10.1890/15-0302.1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Ecological theory, developed largely from ungulates and grassland systems, predicts that herbivory accelerates nutrient cycling more in productive than unproductive systems. This prediction may be important for understanding patterns of ecosystem change over time and space, but its applicability to other ecosystems and types of herbivore remain uncertain. We estimated fluxes of nitrogen (N) and phosphorus (P) from herbivory of a common tree species (Betula pubescens) by a common species of herbivorous insect along a -5000-yr boreal chronosequence. Contrary to established theory, fluxes of N and P via herbivory increased along the chronosequence despite a decline in plant productivity. The herbivore-mediated N and P fluxes to the soil are comparable to the main alternative pathway for these nutrients via tree leaf litterfall. We conclude that insect herbivores can make large contributions to nutrient cycling even in unproductive systems, and influence the rate and pattern of ecosystem development, particularly in systems with low external nutrient inputs.
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22
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Rosenblatt AE, Crowley BT, Schmitz OJ. Linking trophic interactions to plasticity in thermal sensitivity of geographically separated populations of a herbivore. Evol Ecol 2016. [DOI: 10.1007/s10682-016-9827-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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23
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Muth NZ, Kluger EC, Levy JH, Edwards MJ, Niesenbaum RA. Increased per capita herbivory in the shade: Necessity, feedback, or luxury consumption? ECOSCIENCE 2015. [DOI: 10.2980/15-2-3095] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Norris Z. Muth
- Biology Department, Muhlenberg College, Allentown, Pennsylvania 18104-5586, USA,
| | - Emily C. Kluger
- Biology Department, Muhlenberg College, Allentown, Pennsylvania 18104-5586, USA,
| | - Jennifer H. Levy
- Biology Department, Muhlenberg College, Allentown, Pennsylvania 18104-5586, USA,
| | - Marten J. Edwards
- Biology Department, Muhlenberg College, Allentown, Pennsylvania 18104-5586, USA,
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24
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Liman A, Dalin P, Björkman C. Detectability of landscape effects on recolonization increases with regional population density. Ecol Evol 2015; 5:2694-702. [PMID: 26257881 PMCID: PMC4523364 DOI: 10.1002/ece3.1527] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 04/15/2015] [Accepted: 04/19/2015] [Indexed: 11/28/2022] Open
Abstract
Variation in population size over time can influence our ability to identify landscape-moderated differences in community assembly. To date, however, most studies at the landscape scale only cover snapshots in time, thereby overlooking the temporal dynamics of populations and communities. In this paper, we present data that illustrate how temporal variation in population density at a regional scale can influence landscape-moderated variation in recolonization and population buildup in disturbed habitat patches. Four common insect species, two omnivores and two herbivores, were monitored over 8 years in 10 willow short-rotation coppice bio-energy stands with a four-year disturbance regime (coppice cycle). The population densities in these regularly disturbed stands were compared to densities in 17 undisturbed natural Salix cinerea (grey willow) stands in the same region. A time series approach was used, utilizing the natural variation between years to statistically model recolonization as a function of landscape composition under two different levels of regional density. Landscape composition, i.e. relative amount of forest vs. open agricultural habitats, largely determined the density of re-colonizing populations following willow coppicing in three of the four species. However, the impact of landscape composition was not detectable in years with low regional density. Our results illustrate that landscape-moderated recolonization can change over time and that considering the temporal dynamics of populations may be crucial when designing and evaluating studies at landscape level.
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Affiliation(s)
- Anna‐Sara Liman
- Department of Ecology Swedish University of Agricultural Sciences Uppsala Sweden
| | - Peter Dalin
- Department of Ecology Swedish University of Agricultural Sciences Uppsala Sweden
| | - Christer Björkman
- Department of Ecology Swedish University of Agricultural Sciences Uppsala Sweden
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25
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Lu X, Siemann E, Wei H, Shao X, Ding J. Effects of warming and nitrogen on above- and below-ground herbivory of an exotic invasive plant and its native congener. Biol Invasions 2015. [DOI: 10.1007/s10530-015-0918-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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26
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Laws AN, Joern A. Predator-Prey Interactions are Context Dependent in a Grassland Plant-Grasshopper-Wolf Spider Food Chain. ENVIRONMENTAL ENTOMOLOGY 2015; 44:519-528. [PMID: 26313957 DOI: 10.1093/ee/nvv033] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 02/12/2015] [Indexed: 06/04/2023]
Abstract
Species interactions are often context dependent, where outcomes vary in response to one or more environmental factors. It remains unclear how abiotic conditions like temperature combine with biotic factors such as consumer density or food quality to affect resource availability or influence species interactions. Using the large grasshopper Melanoplus bivittatus (Say) and a common wolf spider [Rabidosa rabida (Walkenaer)], we conducted manipulative field experiments in tallgrass prairie to examine how spider-grasshopper interactions respond to manipulations of temperature, grasshopper density, and food quality. Grasshopper survival was density dependent, as were the effects of spider presence and food quality in context-dependent ways. In high grasshopper density treatments, predation resulted in increased grasshopper survival, likely as a result of reduced intraspecific competition in the presence of spiders. Spiders had no effect on grasshopper survival when grasshoppers were stocked at low densities. Effects of the experimental treatments were often interdependent so that effects were only observed when examined together with other treatments. The occurrence of trophic cascades was context dependent, where the effects of food quality and spider presence varied with temperature under high-density treatments. Temperature weakly affected the impact of spider presence on M. bivittatus survivorship when all treatments were considered simultaneously, but different context-dependent responses to spider presence and food quality were observed among the three temperature treatments under high-density conditions. Our results indicate that context-dependent species interactions are common and highlight the importance of understanding how key biotic and abiotic factors combine to influence species interactions.
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Affiliation(s)
- Angela N Laws
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
| | - Anthony Joern
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA.Present address: Department of Biology, University of Notre Dame, Notre Dame, IN, USA.
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27
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Becerra JX. On the factors that promote the diversity of herbivorous insects and plants in tropical forests. Proc Natl Acad Sci U S A 2015; 112:6098-103. [PMID: 25902509 PMCID: PMC4434756 DOI: 10.1073/pnas.1418643112] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Some of the most fascinating and challenging questions in ecology are why biodiversity is highest in tropical forests and whether the factors involved are unique to these habitats. I did a worldwide test of the hypotheses that plant community divergence in antiherbivore traits results in higher insect herbivore diversity, and that predominant attack by specialized herbivores promotes plant richness. I found strong correlative support for both ideas. Butterfly diversity was greatest in regions where the community average species-pairwise dissimilarity in antiherbivore traits among plant species was highest. There was also a strong positive relationship between specialized (insect) vs. generalized (mammal) herbivores and plant richness. Regions where herbivory impact by mammals was higher than that of insects tended to have lower plant diversities. In contrast, regions in which insects are the main consumers, particularly in the Central and South American tropics, had the highest plant richness. Latitude did not explain any residual variance in insect or plant richness. The strong connections found between insect specialization, plant defense divergence, and plant and insect diversities suggest that increasing our understanding of the ecology of biological communities can aid in considerations of how to preserve biodiversity in the future.
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Affiliation(s)
- Judith X Becerra
- Department of Biosphere 2, University of Arizona, Tucson, AZ 85721
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28
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Lu J, Robert CAM, Riemann M, Cosme M, Mène-Saffrané L, Massana J, Stout MJ, Lou Y, Gershenzon J, Erb M. Induced jasmonate signaling leads to contrasting effects on root damage and herbivore performance. PLANT PHYSIOLOGY 2015; 167:1100-16. [PMID: 25627217 PMCID: PMC4348761 DOI: 10.1104/pp.114.252700] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Accepted: 01/24/2015] [Indexed: 05/18/2023]
Abstract
Induced defenses play a key role in plant resistance against leaf feeders. However, very little is known about the signals that are involved in defending plants against root feeders and how they are influenced by abiotic factors. We investigated these aspects for the interaction between rice (Oryza sativa) and two root-feeding insects: the generalist cucumber beetle (Diabrotica balteata) and the more specialized rice water weevil (Lissorhoptrus oryzophilus). Rice plants responded to root attack by increasing the production of jasmonic acid (JA) and abscisic acid, whereas in contrast to in herbivore-attacked leaves, salicylic acid and ethylene levels remained unchanged. The JA response was decoupled from flooding and remained constant over different soil moisture levels. Exogenous application of methyl JA to the roots markedly decreased the performance of both root herbivores, whereas abscisic acid and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid did not have any effect. JA-deficient antisense 13-lipoxygenase (asLOX) and mutant allene oxide cyclase hebiba plants lost more root biomass under attack from both root herbivores. Surprisingly, herbivore weight gain was decreased markedly in asLOX but not hebiba mutant plants, despite the higher root biomass removal. This effect was correlated with a herbivore-induced reduction of sucrose pools in asLOX roots. Taken together, our experiments show that jasmonates are induced signals that protect rice roots from herbivores under varying abiotic conditions and that boosting jasmonate responses can strongly enhance rice resistance against root pests. Furthermore, we show that a rice 13-lipoxygenase regulates root primary metabolites and specifically improves root herbivore growth.
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Affiliation(s)
- Jing Lu
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany (J.L., C.A.M.R., J.G., M.E.);Institute of Plant Sciences, University of Bern, 3013 Bern, Switzerland (C.A.M.R., M.E.);Karlsruhe Institute of Technology, Botanical Institute-Molecular Cell Biology, 76131 Karlsruhe, Germany (M.R.);Functional Biodiversity, Dahlem Center of Plant Sciences, Freie Universität Berlin, 14195 Berlin, Germany (M.C.);Department of Plant Biology, University of Fribourg, 1700 Fribourg, Switzerland (L.M.-S., J.M.);Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803 (M.J.S.); andInstitute of Insect Science, Zijingang Campus, Zhejiang University, Hangzhou 310058, China (Y.L.)
| | - Christelle Aurélie Maud Robert
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany (J.L., C.A.M.R., J.G., M.E.);Institute of Plant Sciences, University of Bern, 3013 Bern, Switzerland (C.A.M.R., M.E.);Karlsruhe Institute of Technology, Botanical Institute-Molecular Cell Biology, 76131 Karlsruhe, Germany (M.R.);Functional Biodiversity, Dahlem Center of Plant Sciences, Freie Universität Berlin, 14195 Berlin, Germany (M.C.);Department of Plant Biology, University of Fribourg, 1700 Fribourg, Switzerland (L.M.-S., J.M.);Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803 (M.J.S.); andInstitute of Insect Science, Zijingang Campus, Zhejiang University, Hangzhou 310058, China (Y.L.)
| | - Michael Riemann
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany (J.L., C.A.M.R., J.G., M.E.);Institute of Plant Sciences, University of Bern, 3013 Bern, Switzerland (C.A.M.R., M.E.);Karlsruhe Institute of Technology, Botanical Institute-Molecular Cell Biology, 76131 Karlsruhe, Germany (M.R.);Functional Biodiversity, Dahlem Center of Plant Sciences, Freie Universität Berlin, 14195 Berlin, Germany (M.C.);Department of Plant Biology, University of Fribourg, 1700 Fribourg, Switzerland (L.M.-S., J.M.);Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803 (M.J.S.); andInstitute of Insect Science, Zijingang Campus, Zhejiang University, Hangzhou 310058, China (Y.L.)
| | - Marco Cosme
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany (J.L., C.A.M.R., J.G., M.E.);Institute of Plant Sciences, University of Bern, 3013 Bern, Switzerland (C.A.M.R., M.E.);Karlsruhe Institute of Technology, Botanical Institute-Molecular Cell Biology, 76131 Karlsruhe, Germany (M.R.);Functional Biodiversity, Dahlem Center of Plant Sciences, Freie Universität Berlin, 14195 Berlin, Germany (M.C.);Department of Plant Biology, University of Fribourg, 1700 Fribourg, Switzerland (L.M.-S., J.M.);Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803 (M.J.S.); andInstitute of Insect Science, Zijingang Campus, Zhejiang University, Hangzhou 310058, China (Y.L.)
| | - Laurent Mène-Saffrané
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany (J.L., C.A.M.R., J.G., M.E.);Institute of Plant Sciences, University of Bern, 3013 Bern, Switzerland (C.A.M.R., M.E.);Karlsruhe Institute of Technology, Botanical Institute-Molecular Cell Biology, 76131 Karlsruhe, Germany (M.R.);Functional Biodiversity, Dahlem Center of Plant Sciences, Freie Universität Berlin, 14195 Berlin, Germany (M.C.);Department of Plant Biology, University of Fribourg, 1700 Fribourg, Switzerland (L.M.-S., J.M.);Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803 (M.J.S.); andInstitute of Insect Science, Zijingang Campus, Zhejiang University, Hangzhou 310058, China (Y.L.)
| | - Josep Massana
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany (J.L., C.A.M.R., J.G., M.E.);Institute of Plant Sciences, University of Bern, 3013 Bern, Switzerland (C.A.M.R., M.E.);Karlsruhe Institute of Technology, Botanical Institute-Molecular Cell Biology, 76131 Karlsruhe, Germany (M.R.);Functional Biodiversity, Dahlem Center of Plant Sciences, Freie Universität Berlin, 14195 Berlin, Germany (M.C.);Department of Plant Biology, University of Fribourg, 1700 Fribourg, Switzerland (L.M.-S., J.M.);Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803 (M.J.S.); andInstitute of Insect Science, Zijingang Campus, Zhejiang University, Hangzhou 310058, China (Y.L.)
| | - Michael Joseph Stout
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany (J.L., C.A.M.R., J.G., M.E.);Institute of Plant Sciences, University of Bern, 3013 Bern, Switzerland (C.A.M.R., M.E.);Karlsruhe Institute of Technology, Botanical Institute-Molecular Cell Biology, 76131 Karlsruhe, Germany (M.R.);Functional Biodiversity, Dahlem Center of Plant Sciences, Freie Universität Berlin, 14195 Berlin, Germany (M.C.);Department of Plant Biology, University of Fribourg, 1700 Fribourg, Switzerland (L.M.-S., J.M.);Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803 (M.J.S.); andInstitute of Insect Science, Zijingang Campus, Zhejiang University, Hangzhou 310058, China (Y.L.)
| | - Yonggen Lou
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany (J.L., C.A.M.R., J.G., M.E.);Institute of Plant Sciences, University of Bern, 3013 Bern, Switzerland (C.A.M.R., M.E.);Karlsruhe Institute of Technology, Botanical Institute-Molecular Cell Biology, 76131 Karlsruhe, Germany (M.R.);Functional Biodiversity, Dahlem Center of Plant Sciences, Freie Universität Berlin, 14195 Berlin, Germany (M.C.);Department of Plant Biology, University of Fribourg, 1700 Fribourg, Switzerland (L.M.-S., J.M.);Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803 (M.J.S.); andInstitute of Insect Science, Zijingang Campus, Zhejiang University, Hangzhou 310058, China (Y.L.)
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany (J.L., C.A.M.R., J.G., M.E.);Institute of Plant Sciences, University of Bern, 3013 Bern, Switzerland (C.A.M.R., M.E.);Karlsruhe Institute of Technology, Botanical Institute-Molecular Cell Biology, 76131 Karlsruhe, Germany (M.R.);Functional Biodiversity, Dahlem Center of Plant Sciences, Freie Universität Berlin, 14195 Berlin, Germany (M.C.);Department of Plant Biology, University of Fribourg, 1700 Fribourg, Switzerland (L.M.-S., J.M.);Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803 (M.J.S.); andInstitute of Insect Science, Zijingang Campus, Zhejiang University, Hangzhou 310058, China (Y.L.)
| | - Matthias Erb
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany (J.L., C.A.M.R., J.G., M.E.);Institute of Plant Sciences, University of Bern, 3013 Bern, Switzerland (C.A.M.R., M.E.);Karlsruhe Institute of Technology, Botanical Institute-Molecular Cell Biology, 76131 Karlsruhe, Germany (M.R.);Functional Biodiversity, Dahlem Center of Plant Sciences, Freie Universität Berlin, 14195 Berlin, Germany (M.C.);Department of Plant Biology, University of Fribourg, 1700 Fribourg, Switzerland (L.M.-S., J.M.);Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803 (M.J.S.); andInstitute of Insect Science, Zijingang Campus, Zhejiang University, Hangzhou 310058, China (Y.L.)
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Nie Y, Zhang Z, Raubenheimer D, Elser JJ, Wei W, Wei F. Obligate herbivory in an ancestrally carnivorous lineage: the giant panda and bamboo from the perspective of nutritional geometry. Funct Ecol 2014. [DOI: 10.1111/1365-2435.12302] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yonggang Nie
- Key Lab of Animal Ecology and Conservation Biology Institute of Zoology Chinese Academy of Sciences 1‐5 Beichenxi RoadChaoyang Beijing 100101 China
| | - Zejun Zhang
- Key Lab of Animal Ecology and Conservation Biology Institute of Zoology Chinese Academy of Sciences 1‐5 Beichenxi RoadChaoyang Beijing 100101 China
| | - David Raubenheimer
- The Charles Perkins Centre and Faculty of Veterinary Science and School of Biological Science The University of Sydney Sydney New South WalesAustralia
| | - James J. Elser
- School of Life Sciences Arizona State University Tempe AZ 85287‐4501 USA
| | - Wei Wei
- Key Lab of Animal Ecology and Conservation Biology Institute of Zoology Chinese Academy of Sciences 1‐5 Beichenxi RoadChaoyang Beijing 100101 China
| | - Fuwen Wei
- Key Lab of Animal Ecology and Conservation Biology Institute of Zoology Chinese Academy of Sciences 1‐5 Beichenxi RoadChaoyang Beijing 100101 China
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van Klink R, van der Plas F, van Noordwijk CGET, WallisDeVries MF, Olff H. Effects of large herbivores on grassland arthropod diversity. Biol Rev Camb Philos Soc 2014; 90:347-66. [PMID: 24837856 PMCID: PMC4402009 DOI: 10.1111/brv.12113] [Citation(s) in RCA: 164] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 04/10/2014] [Accepted: 04/15/2014] [Indexed: 11/27/2022]
Abstract
Both arthropods and large grazing herbivores are important components and drivers of biodiversity in grassland ecosystems, but a synthesis of how arthropod diversity is affected by large herbivores has been largely missing. To fill this gap, we conducted a literature search, which yielded 141 studies on this topic of which 24 simultaneously investigated plant and arthropod diversity. Using the data from these 24 studies, we compared the responses of plant and arthropod diversity to an increase in grazing intensity. This quantitative assessment showed no overall significant effect of increasing grazing intensity on plant diversity, while arthropod diversity was generally negatively affected. To understand these negative effects, we explored the mechanisms by which large herbivores affect arthropod communities: direct effects, changes in vegetation structure, changes in plant community composition, changes in soil conditions, and cascading effects within the arthropod interaction web. We identify three main factors determining the effects of large herbivores on arthropod diversity: (i) unintentional predation and increased disturbance, (ii) decreases in total resource abundance for arthropods (biomass) and (iii) changes in plant diversity, vegetation structure and abiotic conditions. In general, heterogeneity in vegetation structure and abiotic conditions increases at intermediate grazing intensity, but declines at both low and high grazing intensity. We conclude that large herbivores can only increase arthropod diversity if they cause an increase in (a)biotic heterogeneity, and then only if this increase is large enough to compensate for the loss of total resource abundance and the increased mortality rate. This is expected to occur only at low herbivore densities or with spatio-temporal variation in herbivore densities. As we demonstrate that arthropod diversity is often more negatively affected by grazing than plant diversity, we strongly recommend considering the specific requirements of arthropods when applying grazing management and to include arthropods in monitoring schemes. Conservation strategies aiming at maximizing heterogeneity, including regulation of herbivore densities (through human interventions or top-down control), maintenance of different types of management in close proximity and rotational grazing regimes, are the most promising options to conserve arthropod diversity.
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Affiliation(s)
- R van Klink
- Community and Conservation Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
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31
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Mesoherbivores affect grasshopper communities in a megaherbivore-dominated South African savannah. Oecologia 2014; 175:639-49. [PMID: 24705648 DOI: 10.1007/s00442-014-2920-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2013] [Accepted: 03/05/2014] [Indexed: 10/25/2022]
Abstract
African savannahs are among the few places on earth where diverse communities of mega- and meso-sized ungulate grazers dominate ecosystem functioning. Less conspicuous, but even more diverse, are the communities of herbivorous insects such as grasshoppers, which share the same food. Various studies investigated the community assembly of these groups separately, but it is poorly known how ungulate communities shape grasshopper communities. Here, we investigated how ungulate species of different body size alter grasshopper communities in a South African savannah. White rhino is the most abundant vertebrate herbivore in our study site. Other common mesoherbivores include buffalo, zebra and impala. We hypothesized that white rhinos would have greater impact than mesoherbivores on grasshopper communities. Using 10-year-old exclosures, at eight sites we compared the effects of ungulates on grasshopper communities in three nested treatments: (i) unfenced plots ('control plots') with all vertebrate herbivores present, (ii) plots with a low cable fence, excluding white rhino ('megaherbivore exclosures'), and (iii) plots with tall fences, excluding all herbivores larger than rodents ('complete ungulate exclosures'). In each plot, we collected data of vegetation structure, grass and grasshopper community composition. Complete ungulate exclosures contained 30% taller vegetation than megaherbivore exclosures and they were dominated by different grass and grasshopper species. Grasshoppers in complete ungulate exclosures were on average 3.5 mm longer than grasshoppers in megaherbivore exclosures, possibly due to changes in plant communities or vegetation structure. We conclude that surprisingly, in this megaherbivore hotspot, mesoherbivores, instead of megaherbivores, most strongly affect grasshopper communities.
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Borowicz VA. The impact of arbuscular mycorrhizal fungi on plant growth following herbivory: A search for pattern. ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY 2013. [DOI: 10.1016/j.actao.2013.06.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Gornish ES, Tylianakis JM. Community shifts under climate change: mechanisms at multiple scales. AMERICAN JOURNAL OF BOTANY 2013; 100:1422-1434. [PMID: 23825134 DOI: 10.3732/ajb.1300046] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
PREMISE OF THE STUDY Processes that drive ecological dynamics differ across spatial scales. Therefore, the pathways through which plant communities and plant-insect relationships respond to changing environmental conditions are also expected to be scale-dependent. Furthermore, the processes that affect individual species or interactions at single sites may differ from those affecting communities across multiple sites. METHODS We reviewed and synthesized peer-reviewed literature to identify patterns in biotic or abiotic pathways underpinning changes in the composition and diversity of plant communities under three components of climate change (increasing temperature, CO2, and changes in precipitation) and how these differ across spatial scales. We also explored how these changes to plants affect plant-insect interactions. KEY RESULTS The relative frequency of biotic vs. abiotic pathways of climate effects at larger spatial scales often differ from those at smaller scales. Local-scale studies show variable responses to climate drivers, often driven by biotic factors. However, larger scale studies identify changes to species composition and/or reduced diversity as a result of abiotic factors. Differing pathways of climate effects can result from different responses of multiple species, habitat effects, and differing effects of invasions at local vs. regional to global scales. Plant community changes can affect higher trophic levels as a result of spatial or phenological mismatch, foliar quality changes, and plant abundance changes, though studies on plant-insect interactions at larger scales are rare. CONCLUSIONS Climate-induced changes to plant communities will have considerable effects on community-scale trophic exchanges, which may differ from the responses of individual species or pairwise interactions.
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Affiliation(s)
- Elise S Gornish
- Department of Biological Science, Florida State University, Tallahassee, Florida 32306-4295, USA.
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Ebeling A, Allan E, Heimann J, Köhler G, Scherer-Lorenzen M, Vogel A, Weigelt A, Weisser WW. The impact of plant diversity and fertilization on fitness of a generalist grasshopper. Basic Appl Ecol 2013. [DOI: 10.1016/j.baae.2013.01.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Laws AN, Joern A. Predator-prey interactions in a grassland food chain vary with temperature and food quality. OIKOS 2012. [DOI: 10.1111/j.1600-0706.2012.20419.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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36
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Evans DM, Turley NE, Levey DJ, Tewksbury JJ. Habitat patch shape, not corridors, determines herbivory and fruit production of an annual plant. Ecology 2012; 93:1016-25. [DOI: 10.1890/11-0642.1] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Evans LM, Clark JS, Whipple AV, Whitham TG. The relative influences of host plant genotype and yearly abiotic variability in determining herbivore abundance. Oecologia 2011; 168:483-9. [PMID: 21918874 DOI: 10.1007/s00442-011-2108-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Accepted: 06/29/2011] [Indexed: 11/29/2022]
Abstract
Both plant genotype and yearly abiotic variation affect herbivore population sizes, but long-term data have rarely been used to contrast the relative contributions of each. Using a hierarchical Bayesian model, we directly compare effects of these two factors on the population size of a common herbivore, Aceria parapopuli, on Populus angustifolia × fremontii F(1) hybrid trees growing in a common garden across 8 years. Several patterns emerged. First, the Bayesian posterior estimates of tree genotype effects on mite gall number ranged from 0.0043 to 229 on a linear scale. Second, year effect sizes across 8 years of study ranged from 0.133 to 1.895. Third, in comparing the magnitudes of genotypic versus yearly variation, we found that genotypic variation was over 130 times greater than variation among years. Fourth, precipitation in the previous year negatively affected gall abundances, but was minimal compared to tree genotype effects. These findings demonstrate the relative importance of tree genotypic variation in determining herbivore population size. However, given the demonstrated sensitivity of cottonwoods to drought, the loss of individual tree genotypes from an altered climate would have catastrophic impacts on mites that are dependent upon these genotypes for their survival.
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Affiliation(s)
- Luke M Evans
- Department of Biological Sciences, The Environmental Genetics and Genomics Laboratory and Merriam-Powell Center for Environmental Research, Northern Arizona University, PO Box 5640, Flagstaff, AZ 86011, USA.
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Hoekman D. Turning up the heat: temperature influences the relative importance of top-down and bottom-up effects. Ecology 2011; 91:2819-25. [PMID: 21058543 DOI: 10.1890/10-0260.1] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Understanding how communities respond to changes in temperature is a major challenge for community ecology. Temperature influences the relative degree to which top-down and bottom-up forces structure ecological communities. In greenhouse experiments using the aquatic community found in pitcher plants (Sarracenia purpurea), I tested how temperature affected the relative importance of top-down (mosquito predation) and bottom-up (ant carcasses) forces on protozoa and bacteria populations. While bottom-up effects did not vary consistently with temperature, the top-down effects of predators on protozoa increased at higher temperatures. These results suggest that temperature could change the relative importance of top-down and bottom-up effects in ecological communities. Specifically, higher temperature may increase the strength of top-down effects by raising predator metabolic rate and concomitant processes (e.g., activity, foraging, digestion, growth) relative to cooler temperatures. These findings apply broadly to an understanding of trophic interactions in a variable environment and are especially relevant in the context of ongoing climate change.
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Affiliation(s)
- David Hoekman
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, USA.
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de Wysiecki ML, Arturi M, Torrusio S, Cigliano MM. Influence of weather variables and plant communities on grasshopper density in the Southern Pampas, Argentina. JOURNAL OF INSECT SCIENCE (ONLINE) 2011; 11:109. [PMID: 22220572 PMCID: PMC3281369 DOI: 10.1673/031.011.10901] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
A study was conducted to evaluate the influence of weather (precipitation and temperature) and plant communities on grasshopper density over a 14-year period (1996-2009) in Benito Juárez County, Southern Pampas, Argentina. Total density strongly varied among plant communities. Highest values were registered in 2001 and 2003 in highly disturbed pastures and in 2002 and 2009 in halophilous grasslands. Native grasslands had the lowest density values. Seasonal precipitation and temperature had no significant effect on total grasshopper density. Dichroplus elongatus (Giglio-Tos) (Orthoptera: Acridoidea), Covasacris pallidinota (Bruner), Dichroplus pratensis Bruner, Scotussa lemniscata Stål, Borellia bruneri (Rehn) and Dichroplus maculipennis (Blanchard) comprised, on average, 64% of the grasshopper assemblages during low density years and 79% during high density years. Dichroplus elongatus, S. lemniscata and C. pallidinota were the most abundant species in 2001, 2002 and 2003, while D. elongatus, B. brunneri and C. pallidinota in 2009. Dichroplus elongatus and D. pratensis, mixed feeders species, were positively affected by summer rainfall. This suggests that the increase in summer precipitation had a positive effect on the quantity and quality forage production, affecting these grasshopper populations. Scotussa lemniscata and C. pallidinota were negatively affected by winter and fall temperature, possibly affecting the embryonic development before diapause and hatching. Dichroplus elongatus and D. pratensis were associated with highly disturbed pastures, S. lemniscata with pastures and B. bruneri and D. maculipennis with halophilous grasslands. Covasacris pallidinota was closely associated with halophilous grasslands and moderately disturbed pastures. Weather conditions changed over the years, with 2001, 2002 and 2003 having excessive rainfall while 2008 and 2009 were the driest years since the study started. We suggest that although seasonal precipitation and temperature had no significant effect on total grasshopper density, these weather variables and plant communities had differential influence on the dominant grasshopper species.
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Affiliation(s)
- María Laura de Wysiecki
- Centro de Estudios Parasitológicos y de Vectores (CEPAVE), (CCT-La Plata- CONICET- UNLP), Calle 2 n° 584, 1900 La Plata, Argentina
| | - Marcelo Arturi
- LISEA, Facultad de Ciencias Agrarias y Forestales, UNLP. Diagonal 113 n° 469, 1900 La Plata, Argentina
| | - Sandra Torrusio
- Facultad de Ciencias Naturales y Museo, Avda 122 y 60. 1900 La Plata, Argentina
| | - María Marta Cigliano
- División Entomología, Museo de La Plata, Paseo del Bosque s/n. 1900 La Plata, Argentina
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Light environment and the impacts of foliage quality on herbivorous insect attack and bird predation. Oecologia 2010; 166:401-9. [PMID: 21104277 DOI: 10.1007/s00442-010-1840-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Accepted: 10/26/2010] [Indexed: 10/18/2022]
Abstract
Theory predicts that variation in plant traits will modify both the direct interactions between plants and herbivores and the indirect impacts of predators of those herbivores. Light has strong effects on leaf quality, so the impacts of herbivores and predators may differ between plants grown in sun and shade. However, past experiments have often been unable to separate the effects of light environment on plant traits and herbivory from direct effects on herbivores and predators. We first manipulated light availability in an open habitat using a shade cloth pre-treatment to produce oak saplings with different leaf qualities. Leaves on plants exposed to high light were thicker and tougher and had lower nitrogen and water contents, and higher carbon and phenolic contents than leaves on plants under a shade cloth. Then, in the main experiment, we moved all plants to a common shade environment where bird predators were excluded in a factorial design. We measured insect herbivore abundance and leaf damage. Herbivores were significantly more abundant and caused greater leaf damage on sun trees, although these leaf characteristics are usually associated with low-quality food. Bird exclusion did not change herbivore abundance but did increase leaf damage. Contrary to our predictions, the effects of birds did not differ between trees grown in sun and shade conditions. Thus, differences in effects of predators on herbivores and plants between light habitats, when observed, might be due to variation in predator abundance and not bottom-up effects of host plant quality.
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Hoekman D. Relative importance of top-down and bottom-up forces in food webs of Sarracenia pitcher communities at a northern and a southern site. Oecologia 2010; 165:1073-82. [DOI: 10.1007/s00442-010-1802-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Accepted: 09/23/2010] [Indexed: 10/19/2022]
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Mäntylä E, Klemola T, Laaksonen T. Birds help plants: a meta-analysis of top-down trophic cascades caused by avian predators. Oecologia 2010; 165:143-51. [DOI: 10.1007/s00442-010-1774-2] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Accepted: 08/27/2010] [Indexed: 11/27/2022]
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McLauchlan KK, Ferguson CJ, Wilson IE, Ocheltree TW, Craine JM. Thirteen decades of foliar isotopes indicate declining nitrogen availability in central North American grasslands. THE NEW PHYTOLOGIST 2010; 187:1135-1145. [PMID: 20553396 DOI: 10.1111/j.1469-8137.2010.03322.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
*Humans are increasing both the deposition of reactive nitrogen (N) and concentrations of atmospheric CO(2) on Earth, but the combined effects on terrestrial ecosystems are not clear. In the absence of historical records, it is difficult to know if N availability is currently increasing or decreasing on regional scales. *To determine the nature and timing of past changes in grassland ecosystem dynamics, we measured the composition of stable carbon (C) and N isotopes in leaf tissue from 545 herbarium specimens of 24 vascular plant species collected in Kansas, USA from 1876 to 2008. We also parameterized a simple model of the terrestrial N cycle coupled with a stable isotope simulator to constrain processes consistent with observed patterns. *A prolonged decline in foliar N concentrations began in 1926, while a prolonged decline in foliar delta(15)N values began in 1940. Changes in the difference between foliar and atmospheric C isotopes reveal slightly increased photosynthetic water use efficiency since 1876. *The declines in foliar N concentrations and foliar delta(15)N suggest declining N availability in these grasslands during the 20th century despite decades of anthropogenic N deposition. Our results are consistent with progressive-nitrogen-limitation-type hypotheses where declines in N availability are driven by increased ecosystem N storage as a result of increased atmospheric CO(2).
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Affiliation(s)
| | | | - Iris E Wilson
- Department of Geography, Kansas State University, Manhattan, KS 66506, USA
| | - Troy W Ocheltree
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Joseph M Craine
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
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Zehnder CB, Stodola KW, Cooper RJ, Hunter MD. Spatial heterogeneity in the relative impacts of foliar quality and predation pressure on red oak, Quercus rubra, arthropod communities. Oecologia 2010; 164:1017-27. [PMID: 20711610 DOI: 10.1007/s00442-010-1750-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Accepted: 08/02/2010] [Indexed: 10/19/2022]
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Warne RW, Pershall AD, Wolf BO. Linking precipitation and C3-C4 plant production to resource dynamics in higher-trophic-level consumers. Ecology 2010; 91:1628-38. [PMID: 20583705 DOI: 10.1890/08-1471.1] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In many ecosystems, seasonal shifts in temperature and precipitation induce pulses of primary productivity that vary in phenology, abundance, and nutritional quality. Variation in these resource pulses could strongly influence community composition and ecosystem function, because these pervasive bottom-up forces play a primary role in determining the biomass, life cycles, and interactions of organisms across trophic levels. The focus of this research is to understand how consumers across trophic levels alter resource use and assimilation over seasonal and interannual timescales in response to climatically driven changes in pulses of primary productivity. We measured the carbon isotope ratios (delta(13)C) of plant, arthropod, and lizard tissues in the northern Chihuahuan Desert to quantify the relative importance of primary production from plants using C3 and C4 photosynthesis for consumers. Summer monsoonal rains on the Sevilleta Long Term Ecological Research (LTER) site in New Mexico support a pulse of C4 plant production that has tissue delta(13)C values distinct from C3 plants. During a year when precipitation patterns were relatively normal, delta(13)C measurements showed that consumers used and assimilated significantly more C4-derived carbon over the course of a summer, tracking the seasonal increase in abundance of C4 plants. In the following spring, after a failure in winter precipitation and the associated failure of spring C3 plant growth, consumers showed elevated assimilation of C4-derived carbon relative to a normal rainfall regime. These findings provide insight into how climate, pulsed resources, and temporal trophic dynamics may interact to shape semiarid grasslands such as the Chihuahuan Desert in the present and future.
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Affiliation(s)
- Robin W Warne
- University of New Mexico, Biology Department, MSCO3 2020, 1 University of New Mexico, Albuquerque, New Mexico 87131-0001, USA.
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Evaluating Relationships between Spatial Heterogeneity and the Biotic and Abiotic Environments. AMERICAN MIDLAND NATURALIST 2010. [DOI: 10.1674/0003-0031-163.2.351] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Wolkovich EM. Nonnative grass litter enhances grazing arthropod assemblages by increasing native shrub growth. Ecology 2010; 91:756-66. [DOI: 10.1890/09-0147.1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Cronin JP, Tonsor SJ, Carson WP. A simultaneous test of trophic interaction models: which vegetation characteristic explains herbivore control over plant community mass? Ecol Lett 2010; 13:202-12. [DOI: 10.1111/j.1461-0248.2009.01420.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Nutrient supply and bird predation additively control insect herbivory and tree growth in two contrasting forest habitats. OIKOS 2010. [DOI: 10.1111/j.1600-0706.2009.17862.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Invasion of weeping lovegrass reduces native food and habitat resource of Eusphingonotus japonicus (Saussure). Biol Invasions 2010. [DOI: 10.1007/s10530-009-9684-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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