1
|
Muñoz-Gallego R, Wiegand T, Traveset A, Fedriani JM. Sex-driven neighborhood effects on herbivory in the dioecious Mediterranean palm Chamaerops humilis L. Oecologia 2023; 203:151-165. [PMID: 37794240 PMCID: PMC10615982 DOI: 10.1007/s00442-023-05457-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 09/19/2023] [Indexed: 10/06/2023]
Abstract
Although it is well recognized that the strength of plant-herbivore interactions can vary with the plant sex, the distance, and the density of conspecific neighbors, no study has yet assessed their combined influence. Here, we filled this knowledge gap by focusing on the dioecious palm Chamaerops humilis L., and its two main herbivores, the invasive moth Paysandisia archon Burmeister and the feral goat Capra hircus L. We evaluated levels and spatial patterns of herbivory, as well as those of plant size and number of inflorescences in two palm populations in Mallorca (Balearic Islands, Spain). Our spatial point pattern analyses revealed that palms not affected by moth herbivory or goat florivory were spatially aggregated, goats fed more strongly upon inflorescences in palms with more neighbors, but they consumed more leaves in isolated palms. Interestingly, we could reveal for the first time that plant sex is a key plant trait modulating neighborhood effects. For instance, whereas aggregated female palms experienced lower intensity of goat florivory than isolated ones, male palms showed the opposite pattern. Palm size and number of inflorescences also showed sex-related differences, suggesting that sexual dimorphism is a key driver of the observed neighborhood effects on herbivory. Our study highlights the importance of considering relevant plant traits such as sex when investigating plant neighborhood effects, calling for further research to fully understand the dynamics governing plant-herbivore interactions in dioecious systems.
Collapse
Affiliation(s)
- Raquel Muñoz-Gallego
- Global Change Research Group, Mediterranean Institute of Advanced Studies (IMCDEA, CSIC-UIB), C/ Miquel Marquès, 21, 07190, Esporles, Balearic Islands, Spain.
| | - Thorsten Wiegand
- Department of Ecological Modelling, Helmholtz Centre for Environmental Research GmbH-UFZ, Leipzig, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
| | - Anna Traveset
- Global Change Research Group, Mediterranean Institute of Advanced Studies (IMCDEA, CSIC-UIB), C/ Miquel Marquès, 21, 07190, Esporles, Balearic Islands, Spain
| | - Jose M Fedriani
- Desertification Research Centre (CIDE, CSIC), Crta. Moncada-Náquera, Km 4.5, 46113, Moncada, Valencia, Spain.
- Doñana Biological Station (EBD, CSIC), C/Americo Vespucio s/n, 41092, Seville, Spain.
| |
Collapse
|
2
|
Interaction exposure effects of multiple disturbances: plant population resilience to ungulate grazing is reduced by creation of canopy gaps. Sci Rep 2020; 10:1802. [PMID: 32020019 PMCID: PMC7000668 DOI: 10.1038/s41598-020-58672-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 01/15/2020] [Indexed: 11/08/2022] Open
Abstract
The impact of multiple disturbances on populations could be synergistic or antagonistic via disturbance interaction and are considered to be provoked by alternation of the impact of an ecosystem disturbance due to the effect of a preceding disturbance. The impact of a focal disturbance can also change when a preceding disturbance alters the proportion of individuals in a population exposed to these disturbances (i.e., interaction exposure effects), although this effect has not been addressed to date. Herein, we propose and test interaction exposure effects by elucidating disturbance interactions between canopy gap formation and ungulate grazing. Based on a vegetation and seed bank survey conducted on an island in Hokkaido, northern Japan, we examined whether canopy openness changes the impact of ungulate grazing on the occurrence probability of palatable plant species through the facilitation of germination. Species occurrence in the seed bank significantly decreased with increasing canopy openness under the presence of grazing; however, it slightly increased under the absence of grazing, suggesting that gap creation, which facilitates germination, exposes the seed bank to ungulate grazing. Because disturbances of various types often modify the habitat structure, these proposed disturbance interactions are expected to operate within various ecosystems and taxa.
Collapse
|
3
|
Huang Y, Wang L, Wang D, Zeng DH, Li Y, Liu J, Wang Y. Foraging responses of sheep to plant spatial micro-patterns can cause diverse associational effects of focal plant at individual and population levels. J Anim Ecol 2018; 87:863-873. [PMID: 29430651 DOI: 10.1111/1365-2656.12809] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 12/27/2017] [Indexed: 11/29/2022]
Abstract
Multiple-scale foraging decisions by large herbivores can cause associational effects of focal plant individuals neighboured with different species. Spatial micro-patterns between the focal plant and its neighbouring species within patches can affect herbivore foraging selectivity at within- and between-patch scales, which may consequently lead to associational plant effects occurring at both plant individual and population levels. However, these associational effects have not been explored together in the plant-herbivore interaction studies. We aim to evaluate how plant spatial micro-pattern within different quality patches mediate herbivore foraging selectivity, thereby affecting the associational effects of focal plant individuals and population. Using sheep as the model herbivore and a medium preferred species as the focal plant, we conducted a manipulative experiment by allowing sheep grazing freely among three different quality patches, each of which consisted of preferred, unpreferred and focal plant species with different abundances forming spatially aggregated or dispersed micro-patterns. Results showed that, compared with the aggregated plant micro-pattern, dispersed plant micro-patterns within different quality patches increased sheep within-patch selectivity, and caused diverse associational effects of focal plant individuals. Focal plant individuals experienced neighbour contrast defence (i.e. got protection in the high quality patch) and associational defence (i.e. got protection in the low quality patch), respectively, when plants distributed dispersedly in the low and high quality patch. Focal plant individuals simultaneously experienced associational susceptibility (i.e. got damage in the high quality patch) and neighbour contrast susceptibility (i.e. got damage in the low quality patch) when plants distributed dispersedly in the medium quality patch. Furthermore, dispersed plant micro-patterns reduced sheep foraging selectivity between patches, and led to a lower consumption of focal plant population compared with the aggregated plant micro-pattern. Herbivores adopt different within- and between-patch foraging decisions to maintain a high intake of the preferred species in response to various plant micro-patterns, and consequently cause diverse associational effects of both focal plant individuals and population. These associational effects have important implications for understanding the species coexistence and plant community assembly in the grazing ecosystems.
Collapse
Affiliation(s)
- Yue Huang
- Key Laboratory of Forest and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China.,Key Laboratory of Vegetation Ecology, Institute of Grassland Science, Northeast Normal University, Ministry of Education, Changchun, China
| | - Ling Wang
- Key Laboratory of Vegetation Ecology, Institute of Grassland Science, Northeast Normal University, Ministry of Education, Changchun, China
| | - Deli Wang
- Key Laboratory of Vegetation Ecology, Institute of Grassland Science, Northeast Normal University, Ministry of Education, Changchun, China
| | - De-Hui Zeng
- Key Laboratory of Forest and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Yexing Li
- Key Laboratory of Vegetation Ecology, Institute of Grassland Science, Northeast Normal University, Ministry of Education, Changchun, China
| | - Jun Liu
- College of Horticulture, Shenyang Agricultural University, Shenyang, China
| | - Yue Wang
- College of Veterinary and Animal Science, Heilongjiang Bayi Agricultural University, Daqing, China
| |
Collapse
|
4
|
Champagne E, Moore BD, Côté SD, Tremblay J. Spatial correlations between browsing on balsam fir by white-tailed deer and the nutritional value of neighboring winter forage. Ecol Evol 2018; 8:2812-2823. [PMID: 29531697 PMCID: PMC5838068 DOI: 10.1002/ece3.3878] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 12/20/2017] [Accepted: 12/26/2017] [Indexed: 12/03/2022] Open
Abstract
Associational effects, that is, the influence of neighboring plants on herbivory suffered by a plant, are an outcome of forage selection. Although forage selection is a hierarchical process, few studies have investigated associational effects at multiple spatial scales. Because the nutritional quality of plants can be spatially structured, it might differently influence associational effects across multiple scales. Our objective was to determine the radius of influence of neighbor density and nutritional quality on balsam fir (Abies balsamea) herbivory by white-tailed deer (Odocoileus virginianus) in winter. We quantified browsing rates on fir and the density and quality of neighboring trees in a series of 10-year-old cutovers on Anticosti Island (Canada). We used cross-correlations to investigate relationships between browsing rates and the density and nutritional quality of neighboring trees at distances up to 1,000 m. Balsam fir and white spruce (Picea glauca) fiber content and dry matter in vitro true digestibility were correlated with fir browsing rate at the finest extra-patch scale (across distance of up to 50 m) and between cutover areas (300-400 m). These correlations suggest associational effects, that is, low nutritional quality of neighbors reduces the likelihood of fir herbivory (associational defense). Our results may indicate associational effects mediated by intraspecific variation in plant quality and suggest that these effects could occur at scales from tens to hundreds of meters. Understanding associational effects could inform strategies for restoration or conservation; for example, planting of fir among existing natural regeneration could be concentrated in areas of low nutritional quality.
Collapse
Affiliation(s)
- Emilie Champagne
- Département de biologieCentre d’études nordiques & Chaire de recherche industrielle CRSNG en aménagement intégré des ressources de l’île d'AnticostiUniversité LavalQuébecCanada
- Centre d’étude de la forêtUniversité LavalQuébecCanada
| | - Ben D. Moore
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityRichmondNSWAustralia
| | - Steeve D. Côté
- Département de biologieCentre d’études nordiques & Chaire de recherche industrielle CRSNG en aménagement intégré des ressources de l’île d'AnticostiUniversité LavalQuébecCanada
| | - Jean‐Pierre Tremblay
- Département de biologieCentre d’études nordiques & Chaire de recherche industrielle CRSNG en aménagement intégré des ressources de l’île d'AnticostiUniversité LavalQuébecCanada
- Centre d’étude de la forêtUniversité LavalQuébecCanada
| |
Collapse
|
5
|
Champagne E, Perroud L, Dumont A, Tremblay JP, Côté S. Neighbouring plants and perception of predation risk modulate winter browsing by white-tailed deer (Odocoileus virginianus). CAN J ZOOL 2018. [DOI: 10.1139/cjz-2017-0063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The presence of neighbouring plants and predation risk can affect trophic interactions between plants and herbivores. We hypothesized that the relative preference for neighbouring species would determine winter herbivory and that predation risk would modulate browsing pressure. We tested these hypotheses using feeding trials in two regions with high white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) densities: Outaouais and Anticosti Island (Quebec, Canada). In each, we selected a species of interest and compared browsing rates and time spent foraging with neighbours relatively preferred or avoided. In a subexperiment, we included coyote (Canis latrans Say, 1823) urine to test for threat-sensitive foraging and interactions with neighbour effects. In Outaouais, time spent foraging on the focal species was reduced by the presence of potentially avoided neighbours and deer reduced browsing with increased perceived predation risk. On Anticosti, browsing rates on the focal species increased with avoided neighbours, with no effect of the predator urine. Anticosti deer have been in a predator-free environment for more than 120 years, likely reducing antipredator behaviours. This study demonstrates both neighbour effects and threat-sensitive foraging, phenomena that could interact and thus would benefit from being studied together to better represent trophic interactions in natural environments.
Collapse
Affiliation(s)
- E. Champagne
- Département de biologie, Centre d’études nordiques et Chaire de recherche industrielle CRSNG en aménagement intégré des ressources de l’île d’Anticosti, Université Laval, Québec, QC G1V 0A6, Canada
- Centre d’étude de la forêt, Université Laval, Québec, QC G1V 0A6, Canada
| | - L. Perroud
- Département de biologie, Centre d’études nordiques et Chaire de recherche industrielle CRSNG en aménagement intégré des ressources de l’île d’Anticosti, Université Laval, Québec, QC G1V 0A6, Canada
- Département d’Écologie–Évolution, Université de Bourgogne, Dijon, 21000, France
| | - A. Dumont
- Direction de la gestion de la faune de l’Outaouais, Ministère des Forêts, de la Faune et des Parcs, Gatineau, QC J8T 0B1, Canada
| | - J.-P. Tremblay
- Département de biologie, Centre d’études nordiques et Chaire de recherche industrielle CRSNG en aménagement intégré des ressources de l’île d’Anticosti, Université Laval, Québec, QC G1V 0A6, Canada
- Centre d’étude de la forêt, Université Laval, Québec, QC G1V 0A6, Canada
| | - S.D. Côté
- Département de biologie, Centre d’études nordiques et Chaire de recherche industrielle CRSNG en aménagement intégré des ressources de l’île d’Anticosti, Université Laval, Québec, QC G1V 0A6, Canada
| |
Collapse
|
6
|
Stutz RS, Croak BM, Proschogo N, Banks PB, McArthur C. Olfactory and visual plant cues as drivers of selective herbivory. OIKOS 2016. [DOI: 10.1111/oik.03422] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Rebecca S. Stutz
- School of Life and Environmental Sciences; Univ. of Sydney; Camperdown New South Wales 2006 Australia
- Dept of Zoology; Stockholm Univ.; SE-106 91 Stockholm Sweden
| | - Benjamin M. Croak
- School of Life and Environmental Sciences; Univ. of Sydney; Camperdown New South Wales 2006 Australia
| | - Nicholas Proschogo
- School of Chemistry; Univ. of Sydney; Camperdown New South Wales Australia
| | - Peter B. Banks
- School of Life and Environmental Sciences; Univ. of Sydney; Camperdown New South Wales 2006 Australia
| | - Clare McArthur
- School of Life and Environmental Sciences; Univ. of Sydney; Camperdown New South Wales 2006 Australia
| |
Collapse
|
7
|
Huang Y, Wang L, Wang D, Zeng DH, Liu C. How does the foraging behavior of large herbivores cause different associational plant defenses? Sci Rep 2016; 6:20561. [PMID: 26847834 PMCID: PMC4742796 DOI: 10.1038/srep20561] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 01/06/2016] [Indexed: 11/09/2022] Open
Abstract
The attractant-decoy hypothesis predicts that focal plants can defend against herbivory by neighboring with preferred plant species when herbivores make decisions at the plant species scale. The repellent-plant hypothesis assumes that focal plants will gain protection by associating with nonpreferred neighbors when herbivores are selective at the patch scale. However, herbivores usually make foraging decisions at these scales simultaneously. The net outcomes of the focal plant vulnerability could depend on the spatial scale at which the magnitude of selectivity by the herbivores is stronger. We quantified and compared the within- and between-patch overall selectivity index (OSI) of sheep to examine the relationships between associational plant effects and herbivore foraging selectivity. We found that the sheep OSI was stronger at the within- than the between-patch scale, but focal plant vulnerability followed both hypotheses. Focal plants defended herbivory with preferred neighbors when the OSI difference between the two scales was large. Focal plants gained protection with nonpreferred neighbors when the OSI difference was narrowed. Therefore, the difference in selectivity by the herbivores between the relevant scales results in different associational plant defenses. Our study suggests important implications for understanding plant-herbivore interactions and grassland management.
Collapse
Affiliation(s)
- Yue Huang
- Institute of Grassland Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, 5268 Renmin St., Changchun 130024, P.R. China.,State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, P.R. China
| | - Ling Wang
- Institute of Grassland Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, 5268 Renmin St., Changchun 130024, P.R. China
| | - Deli Wang
- Institute of Grassland Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, 5268 Renmin St., Changchun 130024, P.R. China
| | - De-Hui Zeng
- State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, P.R. China
| | - Chen Liu
- Northwest Polytechnical University, Centre for Ecological and Environmental Sciences, Xi'an, 710072, P.R. China
| |
Collapse
|
8
|
Stutz RS, Banks PB, Dexter N, McArthur C. Herbivore search behaviour drives associational plant refuge. ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY 2015. [DOI: 10.1016/j.actao.2015.05.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
9
|
Prendeville HR, Steven JC, Galloway LF. Spatiotemporal variation in deer browse and tolerance in a woodland herb. Ecology 2015; 96:471-8. [DOI: 10.1890/14-0653.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
10
|
Quantifying the response of free-ranging mammalian herbivores to the interplay between plant defense and nutrient concentrations. Oecologia 2014; 175:1167-77. [DOI: 10.1007/s00442-014-2980-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 05/22/2014] [Indexed: 11/27/2022]
|
11
|
|
12
|
Beard KH, Faulhaber CA, Howe FP, Thomas CE. Rodent-Mediated Interactions Among Seed Species of Differing Quality in a Shrubsteppe Ecosystem. WEST N AM NATURALIST 2013. [DOI: 10.3398/064.073.0415] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
13
|
Roles of the volatile terpene, 1,8-cineole, in plant–herbivore interactions: a foraging odor cue as well as a toxin? Oecologia 2013; 174:827-37. [DOI: 10.1007/s00442-013-2801-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 10/02/2013] [Indexed: 10/26/2022]
|
14
|
Strauss SY, Cacho NI. Nowhere to Run, Nowhere to Hide: The Importance of Enemies and Apparency in Adaptation to Harsh Soil Environments. Am Nat 2013; 182:E1-14. [DOI: 10.1086/670754] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
15
|
Nersesian CL, Banks PB, McArthur C. Influences of Plant Toxins and Their Spatial Distribution on Foraging by the Common Brushtail Possum, a Generalist Mammalian Herbivore. J Chem Ecol 2012. [DOI: 10.1007/s10886-012-0218-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
16
|
Erickson AA, Bell SS, Dawes CJ. Associational resistance protects mangrove leaves from crab herbivory. ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY 2012. [DOI: 10.1016/j.actao.2012.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
17
|
Nersesian CL, Banks PB, Simpson SJ, McArthur C. Mixing nutrients mitigates the intake constraints of a plant toxin in a generalist herbivore. Behav Ecol 2012. [DOI: 10.1093/beheco/ars049] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
18
|
Häsler H, Senn J. Ungulate browsing on European silver firAbies alba: the role of occasions, food shortage and diet preferences. WILDLIFE BIOLOGY 2012. [DOI: 10.2981/09-013] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
|
19
|
Kimball BA, Russell JH, Ott PK. Phytochemical variation within a single plant species influences foraging behavior of deer. OIKOS 2011. [DOI: 10.1111/j.1600-0706.2011.19515.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
20
|
Miranda M, Díaz L, Sicilia M, Cristóbal I, Cassinello J. Seasonality and edge effect determine herbivory risk according to different plant association models. PLANT BIOLOGY (STUTTGART, GERMANY) 2011; 13:160-168. [PMID: 21143737 DOI: 10.1111/j.1438-8677.2009.00316.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We report evidence of hierarchical resource selection by large herbivores and plant neighbouring effects in a Mediterranean ecosystem. Plant palatability was assessed according to herbivore foraging decisions. We hypothesize that under natural conditions large herbivores follow a hierarchical foraging pattern, starting at the landscape scale, and then selecting patches and individual plants. A between- and within-patch selection study was carried out in an area formed by scrubland and pasture patches, connected by habitat edges. With regard to between-patch selection, quality-dependent resource selection is reported: herbivores mainly consume pasture in spring and woody plants in winter. Within-patch selection was also observed in scrub habitats, influenced by season, relative patch palatability and edge effect. We defined a Proximity Index (PI) between palatable and unpalatable plants, which allowed verification of neighbouring effects. In spring, when the preferred food resource (i.e. herbs) is abundant, we observed that in habitat edges large herbivores basically select the relatively scarce palatable shrubs, whereas inside scrubland, unpalatable shrub consumption was related to increasing PI. In winter, a very different picture was observed; there was low consumption of palatable species surrounded by unpalatable species in habitat edges, where the latter were more abundant. These outcomes could be explained though different plant associations described in the literature. We conclude that optimal foraging theory provides a conceptual framework behind the observed interactions between plants and large herbivores in Mediterranean ecosystems.
Collapse
Affiliation(s)
- M Miranda
- Instituto de Investigación en Recursos Cinegéticos (IREC), CSIC-UCLM-JCCM, Ciudad Real, Spain
| | | | | | | | | |
Collapse
|
21
|
Courant S, Fortin D. Foraging decisions of bison for rapid energy gains can explain the relative risk to neighboring plants in complex swards. Ecology 2010; 91:1841-9. [PMID: 20583724 DOI: 10.1890/09-1226.1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Herbivores commonly base their foraging decisions not only on the intrinsic characteristics of plants, but also on the attributes of neighboring species. Although herbivores commonly orient their food choices toward the maximization of energy intake, the impact of such choices on neighboring plants remains largely unexplored. We evaluated whether foraging decisions by herbivores aiming at a rapid intake of digestible energy could explain multiple neighboring effects in complex swards. Specifically, we assessed how spatial patterns of occurrence of Carex atherodes, a highly profitable sedge species, could control the risk of bison (Bison bison) herbivory for seven other plant species. The foraging behavior of 70 free-ranging bison was evaluated in their natural environment during summer, and then related to plant characteristics. We used this information to estimate the instantaneous intake rate of digestible energy at individual feeding stations. We found that neighbor contrast defense and associational susceptibility can both be explained by simple foraging rules of energy maximization. Energy gains were higher when C. atherodes was consumed while avoiding the species for which we detected neighbor contrast defense. The lower intake rate associated with their consumption was due to an increase in handling time caused by their small size relative to C. atherodes. Bison also had higher energy gains by consuming instead of avoiding the plant species that experienced associational susceptibility. Because most of these plants were at least as tall as C. atherodes, their presence increased the heterogeneity of the grazed stratum. Avoiding their consumption increased handling time thereby reducing the instantaneous rate of energy intake. Overall, we found that bison adjust their fine-scale foraging decisions to vertical and horizontal sward structures in a way that maximizes their energy intake rate. Energy maximization principles thus provide a valuable framework to evaluate a broad-range of neighboring effects for prey faced with generalist consumers.
Collapse
Affiliation(s)
- Sabrina Courant
- Centre êde la ForCt and Département de Biologie, Université Laval, 1045 Avenue de la Médecine, Québec G1V0A6, Canada
| | | |
Collapse
|
22
|
Wang L, Wang D, Bai Y, Huang Y, Fan M, Liu J, Li Y. Spatially complex neighboring relationships among grassland plant species as an effective mechanism of defense against herbivory. Oecologia 2010; 164:193-200. [PMID: 20552227 DOI: 10.1007/s00442-010-1676-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Accepted: 05/21/2010] [Indexed: 11/30/2022]
Abstract
Close spatial relationships between plant species are often important for defense against herbivory. The associational plant defense may have important implications for plant community structure, species diversity, and species coexistence. An increasing number of studies have focused on associational plant defense against herbivory at the scale of the individual plant and its nearest neighbors. However, the average neighborhood effects between plant species at the scale of whole plant communities have received almost no attention. The aims of this study were to determine patterns of spatial relationship between different plant species that can provide effective defense against herbivory. We conducted a manipulative experiment using sheep and three native plant species with different palatability. Consumption of palatable plants by herbivores was largest when the three plant species were isolated in three patches and independent of each other. A homogenous and spatially equal neighbor relationship between the three species did not reduce the risk of herbivory of palatable species compared to isolation of these species, but it reduced the total intake of all plant species. The palatable species was subject to less herbivory in a complex spatial neighborhood of several plant species. High complexity of spatial neighborhood resulted in herbivores passively reducing selectivity, thereby reducing the probability of damage to palatable species in the community, or making inaccurate judgments in foraging selectivity between and within patches, thereby reducing the vulnerability of palatable plants and even the whole plant community. We conclude that compelling herbivores to passively reduce the magnitude of foraging selectivity by establishing spatially complex neighborhoods between plant species is a compromise and optimal spatial strategy by plants to defend themselves again herbivory. This may contribute not only to maintenance of plant species diversity but also to a stable coexistence between herbivores and plants in grassland ecosystems.
Collapse
Affiliation(s)
- Ling Wang
- Key Laboratory of Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, 130024, People's Republic of China
| | | | | | | | | | | | | |
Collapse
|
23
|
Wang L, Wang D, Bai Y, Jiang G, Liu J, Huang Y, Li Y. Spatial distributions of multiple plant species affect herbivore foraging selectivity. OIKOS 2010. [DOI: 10.1111/j.1600-0706.2009.17774.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
24
|
Heidel-Fischer HM, Freitak D, Janz N, Söderlind L, Vogel H, Nylin S. Phylogenetic relatedness and host plant growth form influence gene expression of the polyphagous comma butterfly (Polygonia c-album). BMC Genomics 2009; 10:506. [PMID: 19878603 PMCID: PMC2775755 DOI: 10.1186/1471-2164-10-506] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Accepted: 10/31/2009] [Indexed: 11/12/2022] Open
Abstract
Background The mechanisms that shape the host plant range of herbivorous insect are to date not well understood but knowledge of these mechanisms and the selective forces that influence them can expand our understanding of the larger ecological interaction. Nevertheless, it is well established that chemical defenses of plants influence the host range of herbivorous insects. While host plant chemistry is influenced by phylogeny, also the growth forms of plants appear to influence the plant defense strategies as first postulated by Feeny (the "plant apparency" hypothesis). In the present study we aim to investigate the molecular basis of the diverse host plant range of the comma butterfly (Polygonia c-album) by testing differential gene expression in the caterpillars on three host plants that are either closely related or share the same growth form. Results In total 120 genes were identified to be differentially expressed in P. c-album after feeding on different host plants, 55 of them in the midgut and 65 in the restbody of the caterpillars. Expression patterns could be confirmed with an independent method for 14 of 27 tested genes. Pairwise similarities in upregulation in the midgut of the caterpillars were higher between plants that shared either growth form or were phylogenetically related. No known detoxifying enzymes were found to be differently regulated in the midgut after feeding on different host plants. Conclusion Our data suggest a complex picture of gene expression in response to host plant feeding. While each plant requires a unique gene regulation in the caterpillar, both phylogenetic relatedness and host plant growth form appear to influence the expression profile of the polyphagous comma butterfly, in agreement with phylogenetic studies of host plant utilization in butterflies.
Collapse
Affiliation(s)
- Hanna M Heidel-Fischer
- Department of Entomology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Strasse 8, D-07745 Jena, Germany.
| | | | | | | | | | | |
Collapse
|
25
|
Miller AM, McArthur C, Smethurst PJ. Spatial scale and opportunities for choice influence browsing and associational refuges of focal plants. J Anim Ecol 2009; 78:1134-42. [PMID: 19594661 DOI: 10.1111/j.1365-2656.2009.01589.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
1. Foraging decisions by herbivores depend on variation in food types, the scale(s) at which this variation occurs and the opportunity and capacity for herbivores to respond to such variation. These decisions affect not only the herbivores themselves, but also the vulnerability of individual plants to being eaten. Associational plant refuges, in which neighbouring plants alter focal plant vulnerability, are an emergent property of foraging decisions. 2. Using the red-bellied pademelon (Thylogale billardierii) as a model generalist mammalian herbivore, we investigated the spatial scale(s) at which animals made foraging decisions and the resultant effect on focal plant vulnerability. In a replicated design, we varied vegetation at the individual plant scale, generating intraspecific differences in Eucalyptus nitens seedlings by altering their nutrient status (high, low). We varied vegetation at the patch scale, in which seedlings were planted, using high- (grass) and low- (herbicided) quality patches. Animals were allowed to choose where they fed and what they ate. Animal behaviour was recorded and intake of seedlings measured. 3. We found that animals made foraging decisions first at the patch scale then at the scale of individual plants; both patch and focal seedling characteristics influenced browsing. Pademelons spent most of their time in high-quality patches, and seedlings were consequently more vulnerable there than in low-quality patches. Pademelons also ate more foliage from high- than from low-nutrient status seedlings. This behaviour concentrated resources, increasing foraging efficiency and making focal plants more vulnerable to browsing. 4. The opportunity and capacity to choose at both plant and patch scales resulted in a pattern of focal plant vulnerability consistent with the repellent-plant hypothesis. This contrasts with our previous study, in which animals were only provided with choice at the plant level and plant vulnerability followed the attractant-decoy hypothesis. These combined results demonstrate that the influence of neighbouring vegetation on consumption of a focal plant depends on the spatial scale of selection and on opportunities (and capacity) for herbivores to choose.
Collapse
|
26
|
Wise MJ, Yi CG, Abrahamson WG. Associational resistance, gall-fly preferences, and a stem dimorphism in Solidago altissima. ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY 2009. [DOI: 10.1016/j.actao.2008.12.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
27
|
Bee JN, Tanentzap AJ, Lee WG, Lavers RB, Mark AF, Mills JA, Coomes DA. The benefits of being in a bad neighbourhood: plant community composition influences red deer foraging decisions. OIKOS 2009. [DOI: 10.1111/j.1600-0706.2008.16756.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|