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Massad TJ, Richards LA, Philbin C, Fumiko Yamaguchi L, Kato MJ, Jeffrey CS, Oliveira C, Ochsenrider K, M de Moraes M, Tepe EJ, Cebrian Torrejon G, Sandivo M, Dyer LA. The chemical ecology of tropical forest diversity: Environmental variation, chemical similarity, herbivory, and richness. Ecology 2022; 103:e3762. [PMID: 35593436 DOI: 10.1002/ecy.3762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 03/01/2022] [Accepted: 03/18/2022] [Indexed: 11/11/2022]
Abstract
Species richness in tropical forests is correlated with other dimensions of diversity, including the diversity of plant-herbivore interactions and the phytochemical diversity that influences those interactions. Understanding the complexity of plant chemistry and the importance of phytochemical diversity for plant-insect interactions and overall forest richness has been enhanced significantly by the application of metabolomics to natural systems. The present work used proton nuclear magnetic resonance spectroscopy (1 H-NMR) profiling of crude leaf extracts to study phytochemical similarity and diversity among Piper plants growing naturally in the Atlantic Rainforest of Brazil. Spectral profile similarity and chemical diversity were quantified to examine the relationship between metrics of phytochemical diversity, specialist and generalist herbivory, and understory plant richness. Herbivory increased with understory species richness, while generalist herbivory increased and specialist herbivory decreased with the diversity of Piper leaf material available. Specialist herbivory increased when conspecific host plants were more spectroscopically dissimilar. Spectral similarity was lower among individuals of common species, and they were also more spectrally diverse, indicating phytochemical diversity is beneficial to plants. Canopy openness and soil nutrients also influenced chemistry and herbivory. The complex relationships uncovered in this study add information to our growing understanding of the importance of phytochemical diversity for plant-insect interactions and tropical plant species richness.
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Affiliation(s)
- Tara Joy Massad
- Department of Scientific Services, Gorongosa National Park, Sofala, Mozambique.,Instituto de Química, Universidade de São Paulo, São Paulo, São Paulo, Brasil
| | - Lora A Richards
- Department of Biology, Program in Ecology, Evolution and Conservation Biology, University of Nevada, Reno, NV, USA.,Hitchcock Center for Chemical Ecology, University of Nevada, Reno, NV, USA
| | - Casey Philbin
- Hitchcock Center for Chemical Ecology, University of Nevada, Reno, NV, USA.,Department of Chemistry, University of Nevada, Reno, NV, USA
| | | | - Massuo J Kato
- Instituto de Química, Universidade de São Paulo, São Paulo, São Paulo, Brasil
| | - Christopher S Jeffrey
- Hitchcock Center for Chemical Ecology, University of Nevada, Reno, NV, USA.,Department of Chemistry, University of Nevada, Reno, NV, USA
| | - Celso Oliveira
- Department of Chemistry, University of Nevada, Reno, NV, USA
| | | | - Marcílio M de Moraes
- Departamento de Química, Universidade Federal Rural de Pernambuco, Pernambuco, Pernambuco, Brasil
| | - Eric J Tepe
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, USA
| | | | | | - Lee A Dyer
- Department of Biology, Program in Ecology, Evolution and Conservation Biology, University of Nevada, Reno, NV, USA.,Hitchcock Center for Chemical Ecology, University of Nevada, Reno, NV, USA
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Szefer P, Molem K, Sau A, Novotny V. Weak effects of birds, bats, and ants on their arthropod prey on pioneering tropical forest gap vegetation. Ecology 2022; 103:e3690. [PMID: 35322403 DOI: 10.1002/ecy.3690] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 12/18/2021] [Accepted: 01/18/2022] [Indexed: 11/11/2022]
Abstract
The relative roles of plants competing for resources versus top-down control of vegetation by herbivores, in turn impacted by predators, during early stages of tropical forest succession remain poorly understood. Here we examine the impact of insectivorous birds, bats and ants exclusion on arthropods communities on replicated 5x5 m of pioneering early successional vegetation plots in lowland tropical forest gaps in Papua New Guinea. In plots from which focal taxa of predators were excluded we observed increased biomass of herbivorous and predatory arthropods, and increased density, and decreased diversity of herbivorous insects. However, changes in the biomass of plants, herbivores and arthropod predators were positively correlated or uncorrelated between these three trophic levels and also between individual arthropod orders. Arthropod abundance and biomass correlated strongly with the plant biomass irrespective of the arthropods' trophic position - a signal of bottom-up control. Patterns in herbivore specialization confirm lack of a strong top-down control and were largely unaffected by the exclusion of insectivorous birds, bats and ants. No changes of plant-herbivore interaction networks were detected except for decrease in modularity of the exclosure plots. Our results suggest weak top-down control of herbivores, limited compensation between arthropod and vertebrate predators, and limited intra-guild predation by birds, bats and ants. Possible explanations are strong bottom-up control, a low activity of the higher order predators, especially birds, possibly also bats, in gaps, and continuous influx of herbivores from surrounding mature forest matrix.
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Affiliation(s)
- Piotr Szefer
- Faculty of Science, University of South Bohemia, Branišovská 1645/31a, České Budějovice, Czech Republic.,Biology Centre, Institute of Entomology, Czech Academy of Sciences, Branišovská 31, České Budějovice, Czech Republic
| | - Kenneth Molem
- New Guinea Binatang Research Centre, PO Box 604, Madang 511, Papua New Guinea
| | - Austin Sau
- New Guinea Binatang Research Centre, PO Box 604, Madang 511, Papua New Guinea
| | - Vojtech Novotny
- Faculty of Science, University of South Bohemia, Branišovská 1645/31a, České Budějovice, Czech Republic.,Biology Centre, Institute of Entomology, Czech Academy of Sciences, Branišovská 31, České Budějovice, Czech Republic
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Coelho da Silva D, Guimarães ZTM, Ferreira Dos Santos VAH, Grandis A, Palacios CE, Ferreira MJ. Herbivory and leaf traits of Amazonian tree species as affected by irradiance. PLANT BIOLOGY (STUTTGART, GERMANY) 2021; 23:229-240. [PMID: 33012123 DOI: 10.1111/plb.13191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 09/09/2020] [Indexed: 06/11/2023]
Abstract
Herbivory is one of the major biotic stress factors that affect the establishment of plants. However, the main factors that drive herbivory in seedlings of Amazonian tree species are still not well understood. Here we investigated whether contrasting levels of irradiance influence herbivory according to different herbivory indicators and which leaf traits are most related to interspecific variation in herbivory under contrasting irradiance conditions. We measured the leaf area lost as a result of insect herbivory in five tree species planted in a silvicultural system of secondary forest enrichment according to two indicators, herbivore damage (accumulated since plant germination) and herbivory rate (measured over time), and two irradiance conditions, understorey PPFD 2.6 mol·m-2 ·day-1 ) and gap PPFD 33.1 mol·m-2 ·day-1 . Furthermore, we related the interspecific variation in herbivory to a set of leaf traits: SLA, RWC, sclerophylly, phenolic compound content, tannins, condensed tannins and non-structural carbohydrates. Herbivore damage was significantly affected by light availability and species, with the highest percentage variation observed in the Meliaceae (Carapa guianensis and Swietenia macrophylla). For the herbivory rate, only the interspecific variation was significant, with Bertholletia excelsa having the lowest rates. Chemical characteristics (phenolic compounds and tannins) were most related to herbivory rates, as well as highly influenced by light conditions. Non-structural carbohydrates (starch and sucrose) were also related to the interspecific variation in herbivory. The phenolic compounds and starch, as affected by light quantity, are species dependent. Thus, the selective pressure on herbivores may be driven by species-dependent responses to light conditions.
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Affiliation(s)
- D Coelho da Silva
- Department of Forest Sciences, Federal University of Amazonas, Manaus, Amazonas, Brazil
| | - Z T M Guimarães
- Coordination of Environmental Dynamics, National Institute of Amazon Researches, Manaus, Amazonas, Brazil
| | - V A H Ferreira Dos Santos
- Coordination of Environmental Dynamics, National Institute of Amazon Researches, Manaus, Amazonas, Brazil
| | - A Grandis
- Department of Botany, University of São Paulo, São Paulo, Brazil
| | - C E Palacios
- Department of Botany, University of São Paulo, São Paulo, Brazil
| | - M J Ferreira
- Department of Forest Sciences, Federal University of Amazonas, Manaus, Amazonas, Brazil
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