1
|
Carpio AJ, Laguna E, Pascual-Rico R, Martínez-Jauregui M, Guerrero-Casado J, Vicente J, Soriguer RC, Acevedo P. The prohibition of recreational hunting of wild ungulates in Spanish National Parks: Challenges and opportunities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 926:171363. [PMID: 38432372 DOI: 10.1016/j.scitotenv.2024.171363] [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: 08/17/2023] [Revised: 12/05/2023] [Accepted: 02/27/2024] [Indexed: 03/05/2024]
Abstract
A new regulation has led to the prohibition of recreational hunting on estates located within Spanish National Parks (NPs). Before the ban, eleven NPs in Spain had already reported negative ecological consequences associated with high densities of wild ungulates. The new situation that has occurred after the ban signifies that policies with which to control populations of wild ungulates in NPs, most of which do not have a sufficient natural capacity to regulate populations, depend exclusively on the parks' authorities. The banning of recreational hunting implies a series of social, ecological, economic and logistic challenges. The control of wild ungulate populations in NPs requires: i) the legal basis for culling; ii) social acceptance as regards removing animals and the extractive procedures employed in NPs; iii) the long-term monitoring of wild ungulates and the damages that they cause, and iv) sufficient financial and human resources. A more integrated management and policy plan is, therefore, required, which should be supported by two pillars: i) the sustainability of natural resources and the conservation of functional environments, and ii) providing society with explanations regarding the need to manage wild ungulates. In order to bridge the potential gap between these key pillars, it is important to involve stakeholders in the decision-making processes concerning wild ungulate management. The forthcoming changes in Spanish NPs provide a promising opportunity to make a substantial improvement to wild ungulate management in these protected areas. This management approach could, moreover, serve as an example and be transferred to other protected spaces.
Collapse
Affiliation(s)
- Antonio J Carpio
- Instituto de Investigación en Recursos Cinegéticos, IREC (UCLM-CSIC-JCCM), Ronda Toledo 12, 13071 Ciudad Real, Spain.
| | - Eduardo Laguna
- Instituto de Investigación en Recursos Cinegéticos, IREC (UCLM-CSIC-JCCM), Ronda Toledo 12, 13071 Ciudad Real, Spain.
| | - Roberto Pascual-Rico
- Instituto de Investigación en Recursos Cinegéticos, IREC (UCLM-CSIC-JCCM), Ronda Toledo 12, 13071 Ciudad Real, Spain.
| | - María Martínez-Jauregui
- National Institute for Agriculture and Food Research and Technology (INIA), Forest Research Centre (CIFOR), Ctra. de La Coruña km. 7.5, 28040 Madrid, Spain.
| | - José Guerrero-Casado
- Departamento de Zoología, Universidad de Córdoba, Edificio Charles Darwin, Campus de Rabanales, 14071, Spain.
| | - Joaquín Vicente
- Instituto de Investigación en Recursos Cinegéticos, IREC (UCLM-CSIC-JCCM), Ronda Toledo 12, 13071 Ciudad Real, Spain.
| | - Ramón C Soriguer
- Estación Biológica de Doñana (CSIC), Av. Américo Vespucio, s.n, E-41092 Sevilla,Spain.
| | - Pelayo Acevedo
- Instituto de Investigación en Recursos Cinegéticos, IREC (UCLM-CSIC-JCCM), Ronda Toledo 12, 13071 Ciudad Real, Spain.
| |
Collapse
|
2
|
Rhodes AC, Plowes RM, Bowman EA, Gaitho A, Ng'Iru I, Martins DJ, Gilbert LE. Systematic reduction of natural enemies and competition across variable precipitation approximates buffelgrass invasiveness ( Cenchrus ciliaris) in its native range. Ecol Evol 2024; 14:e11350. [PMID: 38737568 PMCID: PMC11087885 DOI: 10.1002/ece3.11350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 03/28/2024] [Accepted: 04/12/2024] [Indexed: 05/14/2024] Open
Abstract
Invasive grasses cause devastating losses to biodiversity and ecosystem function directly and indirectly by altering ecosystem processes. Escape from natural enemies, plant-plant competition, and variable resource availability provide frameworks for understanding invasion. However, we lack a clear understanding of how natural stressors interact in their native range to regulate invasiveness. In this study, we reduced diverse guilds of natural enemies and plant competitors of the highly invasive buffelgrass across a precipitation gradient throughout major climatic shifts in Laikipia, Kenya. To do this, we used a long-term ungulate exclosure experiment design across a precipitation gradient with nested treatments that (1) reduced plant competition through clipping, (2) reduced insects through systemic insecticide, and (3) reduced fungal associates through fungicide application. Additionally, we measured the interaction of ungulates on two stem-boring insect species feeding on buffelgrass. Finally, we measured a multiyear smut fungus outbreak. Our findings suggest that buffelgrass exhibits invasive qualities when released from a diverse group of natural stressors in its native range. We show natural enemies interact with precipitation to alter buffelgrass productivity patterns. In addition, interspecific plant competition decreased the basal area of buffelgrass, suggesting that biotic resistance mediates buffelgrass dominance in the home range. Surprisingly, systemic insecticides and fungicides did not impact buffelgrass production or reproduction, perhaps because other guilds filled the niche space in these highly diverse systems. For example, in the absence of ungulates, we showed an increase in host-specific stem-galling insects, where these insects compensated for reduced ungulate use. Finally, we documented a smut outbreak in 2020 and 2021, corresponding to highly variable precipitation patterns caused by a shifting Indian Ocean Dipole. In conclusion, we observed how reducing natural enemies and competitors and certain interactions increased properties related to buffelgrass invasiveness.
Collapse
Affiliation(s)
- Aaron C. Rhodes
- Brackenridge Field LaboratoryThe University of Texas at AustinAustinTexasUSA
| | - Robert M. Plowes
- Brackenridge Field LaboratoryThe University of Texas at AustinAustinTexasUSA
| | - Elizabeth A. Bowman
- Brackenridge Field LaboratoryThe University of Texas at AustinAustinTexasUSA
- Hiro Technologies, IncAustinTexasUSA
| | - Aimee Gaitho
- Mpala Research Centre NanyukiNanyukiKenya
- Turkana Basin InstituteNairobiKenya
| | - Ivy Ng'Iru
- UK Centre for Ecology & HydrologyCardiff UniversityWallingfordUK
| | | | - Lawrence E. Gilbert
- Brackenridge Field LaboratoryThe University of Texas at AustinAustinTexasUSA
| |
Collapse
|
3
|
Lundgren EJ, Bergman J, Trepel J, le Roux E, Monsarrat S, Kristensen JA, Pedersen RØ, Pereyra P, Tietje M, Svenning JC. Functional traits-not nativeness-shape the effects of large mammalian herbivores on plant communities. Science 2024; 383:531-537. [PMID: 38301018 DOI: 10.1126/science.adh2616] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 11/30/2023] [Indexed: 02/03/2024]
Abstract
Large mammalian herbivores (megafauna) have experienced extinctions and declines since prehistory. Introduced megafauna have partly counteracted these losses yet are thought to have unusually negative effects on plants compared with native megafauna. Using a meta-analysis of 3995 plot-scale plant abundance and diversity responses from 221 studies, we found no evidence that megafauna impacts were shaped by nativeness, "invasiveness," "feralness," coevolutionary history, or functional and phylogenetic novelty. Nor was there evidence that introduced megafauna facilitate introduced plants more than native megafauna. Instead, we found strong evidence that functional traits shaped megafauna impacts, with larger-bodied and bulk-feeding megafauna promoting plant diversity. Our work suggests that trait-based ecology provides better insight into interactions between megafauna and plants than do concepts of nativeness.
Collapse
Affiliation(s)
- Erick J Lundgren
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO) and Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus, Denmark
- Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Aarhus, Denmark
- School of Biology and Environmental Science, Faculty of Science, Queensland University of Technology, Brisbane City, Queensland, Australia
| | - Juraj Bergman
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO) and Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus, Denmark
- Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Jonas Trepel
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO) and Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus, Denmark
- Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Aarhus, Denmark
- Department of Conservation Biology, University of Göttingen, Göttingen, Germany
| | - Elizabeth le Roux
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO) and Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus, Denmark
- Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Aarhus, Denmark
- Mammal Research Institute, University of Pretoria, Hatfield, South Africa
- Aarhus Institute for Advanced Studies, Aarhus University, Aarhus, Denmark
| | - Sophie Monsarrat
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO) and Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus, Denmark
- Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Aarhus, Denmark
- Rewilding Europe, Nijmegen, Netherlands
| | - Jeppe Aagaard Kristensen
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO) and Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus, Denmark
- Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Aarhus, Denmark
- Leverhulme Centre for Nature Recovery, School of Geography and the Environment, University of Oxford, Oxford, UK
| | - Rasmus Østergaard Pedersen
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO) and Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus, Denmark
- Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Patricio Pereyra
- Consejo Nacional de Investigaciones, Científicas y Técnicas, Ciudad Autónoma de Buenos Aires, Argentina
- Centro de Investigación Aplicada y Transferencia, Tecnológica en Recursos Marinos Almirante Storni (CIMAS), San Antonio Oeste, Argentina
| | - Melanie Tietje
- Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Jens-Christian Svenning
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO) and Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus, Denmark
- Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Aarhus, Denmark
| |
Collapse
|
4
|
Collings J, Endriss SB, Dávalos A. Multiple stressors prevent gains in native plant diversity following invasive species removal. Ecosphere 2023. [DOI: 10.1002/ecs2.4458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023] Open
Affiliation(s)
- Jeremy Collings
- Department of Biological Sciences SUNY Cortland Cortland New York USA
- Department of Biology University of Oregon Eugene Oregon USA
| | - Stacy B. Endriss
- Department of Natural Resources and the Environment Cornell University Ithaca New York USA
- Department of Environmental Sciences University of North Carolina Wilmington Wilmington North Carolina USA
| | - Andrea Dávalos
- Department of Biological Sciences SUNY Cortland Cortland New York USA
| |
Collapse
|
5
|
Hancock LMS, Stinson KA. Trait variation and long-term population dynamics of the invasive Alliaria petiolata (garlic mustard) across three microhabitats. Biol Invasions 2023. [DOI: 10.1007/s10530-022-02990-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
6
|
Doak DF, Waddle E, Langendorf RE, Louthan AM, Chardon NI, Dibner R, Shriver RK, Linares C, Garcia MB, Fitzpatrick SW, Morris WF, DeMarche ML. A critical comparison of integral projection and matrix projection models for demographic analysis: Reply. Ecology 2022; 103:e3822. [PMID: 35861600 DOI: 10.1002/ecy.3822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 05/27/2022] [Accepted: 06/02/2022] [Indexed: 12/13/2022]
Affiliation(s)
- Daniel F Doak
- Department of Environmental Studies, University of Colorado, Boulder, Colorado, USA
| | - Ellen Waddle
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado, USA
| | - Ryan E Langendorf
- Department of Environmental Studies, University of Colorado, Boulder, Colorado, USA.,Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, USA
| | - Allison M Louthan
- Division of Biology, Kansas State University, Manhattan, Kansas, USA.,Department of Biology, Duke University, Durham, North Carolina, USA
| | | | - Reilly Dibner
- Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, USA
| | - Robert K Shriver
- Department of Natural Resources and Environmental Science, University of Nevada, Reno, Nevada, USA
| | - Cristina Linares
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Institut de Recerca de la Biodiversitat (IRBio), University of Barcelona, Barcelona, Spain
| | | | - Sarah W Fitzpatrick
- W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, Michigan, USA
| | - William F Morris
- Department of Biology, Duke University, Durham, North Carolina, USA
| | - Megan L DeMarche
- Plant Biology Department, University of Georgia, Athens, Georgia, USA
| |
Collapse
|
7
|
Morrison JA, Fertitta M, Zymaris C, diBartolo A, Akparanta C. Deer and invasive plants in suburban forests: assessing variation in deer pressure and herbivory. ECOSCIENCE 2022. [DOI: 10.1080/11956860.2021.1958535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
| | - Megan Fertitta
- Department of Biology, The College of New Jersey, Ewing, NJ, USA
| | | | - Amanda diBartolo
- Department of Biology, The College of New Jersey, Ewing, NJ, USA
| | - Chika Akparanta
- Department of Biology, The College of New Jersey, Ewing, NJ, USA
| |
Collapse
|
8
|
Zettlemoyer MA. Monitoring demography of resurrected populations of locally extinct and extant species to investigate drivers of species loss. Am Nat 2022; 200:E36-E51. [DOI: 10.1086/720206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
9
|
The Opposite of Biotic Resistance: Herbivory and Competition Suppress Regeneration of Native but Not Introduced Mangroves in Southern China. FORESTS 2022. [DOI: 10.3390/f13020192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Mangrove forests are increasingly threatened by plant invasions worldwide, but some mangrove species are invasive and threaten salt marsh and native mangrove ecosystems. The southern coast of China is invaded by the cordgrass Spartina alterniflora, and the mangrove Sonneratia apetala, providing a model system for studying the processes and mechanisms through which non-native species establish and spread. We used a transplant experiment to test the overarching hypothesis that native herbivores and plants provided biotic resistance against invasion by S. apetala, and that the importance of these factors would vary geographically. Survival of transplanted mangrove seedlings was lower in Zhangjiang Estuary (23°55′ N) than in Leizhou Bay (20°56′ N), and varied with species and habitats. S. apetala had higher survival and growth rates than native mangroves at both sites, and S. apetala grew taller than the S. alterniflora canopy at Leizhou Bay in only two growing seasons. In contrast, native mangroves grew poorly in S. alterniflora. Grazing by rodents and insects suppressed the growth and survival of Kandelia obovata and Avicennia marina in Zhangjiang Estuary and Leizhou Bay, but had little effect on S. apetala. Competition with vegetation (S. alterniflora and native mangroves) exacerbated the reduced survival of native mangroves, and these effects varied across study sites. Low survival of non-native S. apetala in vegetated habitats at Zhangjiang Estuary was likely due to a synergistic effect of low winter temperatures and low light intensity. Escape from herbivory (the opposite to biotic resistance) and fast growth may drive the quick expansion of non-native S. apetala in China. Rapid encroachment of S. apetala may transform the native mangrove forests and monospecific intertidal Spartina grasslands into non-native mangrove forests in the southern coast of China.
Collapse
|
10
|
Rodgers VL, Scanga SE, Kolozsvary MB, Garneau DE, Kilgore JS, Anderson LJ, Hopfensperger KN, Aguilera AG, Urban RA, Juneau KJ. OUP accepted manuscript. Bioscience 2022; 72:521-537. [PMID: 35677290 PMCID: PMC9169898 DOI: 10.1093/biosci/biac012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The invasive plant Alliaria petiolata (garlic mustard) has spread throughout forest understory and edge communities in much of North America, but its persistence, density, and impacts have varied across sites and time. Surveying the literature since 2008, we evaluated both previously proposed and new mechanisms for garlic mustard's invasion success and note how they interact and vary across ecological contexts. We analyzed how and where garlic mustard has been studied and found a lack of multisite and longitudinal studies, as well as regions that may be under- or overstudied, leading to poor representation for understanding and predicting future invasion dynamics. Inconsistencies in how sampling units are scaled and defined can also hamper our understanding of invasive species. We present new conceptual models for garlic mustard invasion from a macrosystems perspective, emphasizing the importance of synergies and feedbacks among mechanisms across spatial and temporal scales to produce variable ecological contexts.
Collapse
Affiliation(s)
| | | | | | - Danielle E Garneau
- State University of New York Plattsburgh, Plattsburgh, New York, United States
| | - Jason S Kilgore
- Washington and Jefferson College, Washington, Pennsylvania, United States
| | | | | | | | - Rebecca A Urban
- Lebanon Valley College, Annville, Pennsylvania, United States
| | - Kevyn J Juneau
- University of Wisconsin–River Falls, River Falls, Wisconsin, United States
| |
Collapse
|
11
|
Simberloff D, Kaur H, Kalisz S, Bezemer TM. Novel chemicals engender myriad invasion mechanisms. THE NEW PHYTOLOGIST 2021; 232:1184-1200. [PMID: 34416017 DOI: 10.1111/nph.17685] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 08/02/2021] [Indexed: 06/13/2023]
Abstract
Non-native invasive species (NIS) release chemicals into the environment that are unique to the invaded communities, defined as novel chemicals. Novel chemicals impact competitors, soil microbial communities, mutualists, plant enemies, and soil nutrients differently than in the species' native range. Ecological functions of novel chemicals and differences in functions between the native and non-native ranges of NIS are of immense interest to ecologists. Novel chemicals can mediate different ecological, physiological, and evolutionary mechanisms underlying invasion hypotheses. Interactions amongst the NIS and resident species including competitors, soil microbes, and plant enemies, as well as abiotic factors in the invaded community are linked to novel chemicals. However, we poorly understand how these interactions might enhance NIS performance. New empirical data and analyses of how novel chemicals act in the invaded community will fill major gaps in our understanding of the chemistry of biological invasions. A novel chemical-invasion mechanism framework shows how novel chemicals engender invasion mechanisms beyond plant-plant or plant-microorganism interactions.
Collapse
Affiliation(s)
- Daniel Simberloff
- Ecology and Evolutionary Biology Department, University of Tennessee, Knoxville, TN, 37996, USA
| | - Harleen Kaur
- Plant BioSystems, Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
| | - Susan Kalisz
- Ecology and Evolutionary Biology Department, University of Tennessee, Knoxville, TN, 37996, USA
| | - T Martijn Bezemer
- Plant Science and Natural Products, Institute of Biology Leiden (IBL), Leiden University, PO Box 9505, Leiden, 2300 RA, the Netherlands
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), PO Box 6700 AB, Wageningen, the Netherlands
| |
Collapse
|
12
|
Santamaría J, Tomas F, Ballesteros E, Ruiz JM, Bernardeau-Esteller J, Terrados J, Cebrian E. The role of competition and herbivory in biotic resistance against invaders: a synergistic effect. Ecology 2021; 102:e03440. [PMID: 34143423 DOI: 10.1002/ecy.3440] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 04/05/2021] [Indexed: 11/08/2022]
Abstract
Invasive species pose a major threat to global diversity, and once they are well established their eradication typically becomes unfeasible. However, certain natural mechanisms can increase the resistance of native communities to invaders and can be used to guide effective management policies. Both competition and herbivory have been identified as potential biotic resistance mechanisms that can limit plant invasiveness, but it is still under debate to what extent they might be effective against well-established invaders. Surprisingly, whereas biotic mechanisms are known to interact strongly, most studies to date have examined single biotic mechanisms separately, which likely influences our understanding of the strength and effectiveness of biotic resistance against invaders. Here we use long-term field data, benthic assemblage sampling, and exclusion experiments to assess the effect of native assemblage complexity and herbivory on the invasion dynamics of a successful invasive species, the alga Caulerpa cylindracea. A higher complexity of the native algal assemblage limited C. cylindracea invasion, probably through competition by canopy-forming and erect algae. Additionally, high herbivory pressure by the fish Sarpa salpa reduced C. cylindracea abundance by more than four times. However, long-term data of the invasion reflects that biotic resistance strength can vary across the invasion process and it is only where high assemblage complexity is concomitant with high herbivory pressure, that the most significant limitation is observed (synergistic effect). Overall, the findings reported in this study highlight that neglecting the interactions between biotic mechanisms during invasive processes and restricting the studied time scales may lead to underestimations of the true capacity of native assemblages to develop resistance to invaders.
Collapse
Affiliation(s)
- Jorge Santamaría
- Marine Resources and Biodiversity Research Group (GRMAR), Institute of Aquatic Ecology, University of Girona, Girona, 17003, Catalonia, Spain
| | - Fiona Tomas
- Marine Ecosystems Dynamics Group-Instituto Mediterráneo de Estudios Avanzados (IMEDEA), Universitat de les Illes Balears (UIB)-Consejo Superior de Investigaciones Científicas (CSIC), Esporles, 07190, Balearic Islands, Spain
| | - Enric Ballesteros
- Centre d'Estudis Avançats de Blanes, Consejo Superior de Investigaciones Científicas (CEAB-CSIC), Blanes, 17300, Catalonia, Spain
| | - Juan M Ruiz
- Seagrass Ecology Group-Centro Oceanográfico de Murcia, Instituto Español de Oceanografía (IEO), San Pedro del Pinatar, 30740, Murcia, Spain
| | - Jaime Bernardeau-Esteller
- Seagrass Ecology Group-Centro Oceanográfico de Murcia, Instituto Español de Oceanografía (IEO), San Pedro del Pinatar, 30740, Murcia, Spain
| | - Jorge Terrados
- Marine Ecosystems Dynamics Group-Instituto Mediterráneo de Estudios Avanzados (IMEDEA), Universitat de les Illes Balears (UIB)-Consejo Superior de Investigaciones Científicas (CSIC), Esporles, 07190, Balearic Islands, Spain
| | - Emma Cebrian
- Centre d'Estudis Avançats de Blanes, Consejo Superior de Investigaciones Científicas (CEAB-CSIC), Blanes, 17300, Catalonia, Spain
| |
Collapse
|
13
|
Vellend M, Béhé M, Carteron A, Crofts AL, Danneyrolles V, Gamhewa HT, Ni M, Rinas CL, Watts DA. Plant Responses to Climate Change and an Elevational Gradient in Mont Mégantic National Park, Québec, Canada. Northeast Nat (Steuben) 2021. [DOI: 10.1656/045.028.s1102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Mark Vellend
- Département de Biologie, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke, QC J1K 2R1, Canada
| | - Mélanie Béhé
- Département de Biologie, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke, QC J1K 2R1, Canada
| | - Alexis Carteron
- Département de Sciences Biologiques, Institut de Recherche en Biologie Végétale, Centre sur la Biodiversité, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Anna L. Crofts
- Département de Biologie, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke, QC J1K 2R1, Canada
| | - Victor Danneyrolles
- Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, Rimouski, QC G5L 3A1, Canada
| | - Hasanki T. Gamhewa
- Département de Biologie, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke, QC J1K 2R1, Canada
| | - Ming Ni
- Département de Biologie, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke, QC J1K 2R1, Canada
| | - Christina L. Rinas
- Département de Biologie, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke, QC J1K 2R1, Canada
| | - David A. Watts
- Département de Biologie, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke, QC J1K 2R1, Canada
| |
Collapse
|
14
|
Differential and interacting impacts of invasive plants and white-tailed deer in eastern U.S. forests. Biol Invasions 2021. [DOI: 10.1007/s10530-021-02551-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
15
|
Blossey B, Nuzzo V, Dávalos A, Mayer M, Dunbar R, Landis DA, Evans JA, Minter B. Residence time determines invasiveness and performance of garlic mustard (Alliaria petiolata) in North America. Ecol Lett 2021; 24:327-336. [PMID: 33295700 PMCID: PMC7839695 DOI: 10.1111/ele.13649] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/31/2020] [Accepted: 10/29/2020] [Indexed: 11/28/2022]
Abstract
While biological invasions have the potential for large negative impacts on local communities and ecological interactions, increasing evidence suggests that species once considered major problems can decline over time. Declines often appear driven by natural enemies, diseases or evolutionary adaptations that selectively reduce populations of naturalised species and their impacts. Using permanent long-term monitoring locations, we document declines of Alliaria petiolata (garlic mustard) in eastern North America with distinct local and regional dynamics as a function of patch residence time. Projected site-specific population growth rates initially indicated expanding populations, but projected population growth rates significantly decreased over time and at the majority of sites fell below 1, indicating declining populations. Negative soil feedback provides a potential mechanism for the reported disappearance of ecological dominance of A. petiolata in eastern North America.
Collapse
Affiliation(s)
- Bernd Blossey
- Department of Natural ResourcesFernow HallCornell UniversityIthacaNY14853USA
| | - Victoria Nuzzo
- Natural Area Consultants1 West Hill School RoadRichfordNY13835USA
| | - Andrea Dávalos
- Biological Sciences DepartmentSUNY CortlandCortlandNY13045USA
| | - Mark Mayer
- New Jersey Department of AgricultureDivision of Plant IndustryPO Box 330TrentonNJ08625USA
| | - Richard Dunbar
- Division of Nature PreservesIndiana Department of Natural Resources1040 E 700 N Columbia CityIN46725‐8948USA
| | - Douglas A. Landis
- Department of EntomologyMichigan State UniversityEast LansingMI48824USA
| | - Jeffrey A. Evans
- Department of EntomologyMichigan State UniversityEast LansingMI48824USA
- Farmscape Analytics16 Merrimack StConcordNH03301USA
| | - Bill Minter
- Institute for Ecological RegenerationGoshen College1700 South Main StreetGoshenIN46526USA
| |
Collapse
|
16
|
Jackson J, Mar KU, Htut W, Childs DZ, Lummaa V. Changes in age-structure over four decades were a key determinant of population growth rate in a long-lived mammal. J Anim Ecol 2020; 89:2268-2278. [PMID: 32592591 DOI: 10.1111/1365-2656.13290] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 06/04/2020] [Indexed: 11/27/2022]
Abstract
A changing environment directly influences birth and mortality rates, and thus population growth rates. However, population growth rates in the short term are also influenced by population age-structure. Despite its importance, the contribution of age-structure to population growth rates has rarely been explored empirically in wildlife populations with long-term demographic data. Here we assessed how changes in age-structure influenced short-term population dynamics in a semi-captive population of Asian elephants Elephas maximus. We addressed this question using a demographic dataset of female Asian elephants from timber camps in Myanmar spanning 45 years (1970-2014). First, we explored temporal variation in age-structure. Then, using annual matrix population models, we used a retrospective approach to assess the contributions of age-structure and vital rates to short-term population growth rates with respect to the average environment. Age-structure was highly variable over the study period, with large proportions of juveniles in the years 1970 and 1985, and made a substantial contribution to annual population growth rate deviations. High adult birth rates between 1970 and 1980 would have resulted in large positive population growth rates, but these were prevented by a low proportion of reproductive-aged females. We highlight that an understanding of both age-specific vital rates and age-structure is needed to assess short-term population dynamics. Furthermore, this example from a human-managed system suggests that the importance of age-structure may be accentuated in populations experiencing human disturbance where age-structure is unstable, such as those in captivity or for endangered species. Ultimately, changes to the environment drive population dynamics by influencing birth and mortality rates, but understanding demographic structure is crucial for assessing population growth.
Collapse
Affiliation(s)
- John Jackson
- Department of Biology, Interdisciplinary Centre for Population Dynamics, University of Southern Denmark, Odense M, Denmark.,Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - Khyne U Mar
- Department of Biology, University of Turku, Turku, Finland
| | - Win Htut
- Myanma Timber Enterprise, Ministry of Natural Resources and Environment Conservation, Gyogone Forest Compound, Yangon, Myanmar
| | - Dylan Z Childs
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - Virpi Lummaa
- Department of Biology, University of Turku, Turku, Finland
| |
Collapse
|
17
|
Bowe A, Dobson A, Blossey B. Impacts of invasive earthworms and deer on native ferns in forests of northeastern North America. Biol Invasions 2020. [DOI: 10.1007/s10530-020-02195-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
18
|
Bialic-Murphy L, Heckel CD, McElderry RM, Kalisz S. Deer Indirectly Alter the Reproductive Strategy and Operational Sex Ratio of an Unpalatable Forest Perennial. Am Nat 2019; 195:56-69. [PMID: 31868539 DOI: 10.1086/706253] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Environmental conditions impose restrictions and costs on reproduction. Multiple reproductive options exist when increased reproductive costs drive plant populations toward alternative reproductive strategies. Using 4 years of demographic data across a deer impact gradient, where deer alter the abiotic environment, we parameterize a size-dependent integral projection model for a sexually labile and unpalatable forest perennial to investigate the demographic processes driving differentiation in the operational sex ratio (OSR) of local populations. In addition to a relative increase in asexual reproduction, our results illustrate that nontrophic indirect effects by overabundant deer on this perennial result in delayed female sex expression to unsustainably large plant sizes and lead to more pronounced plant shrinkage following female sex expression, effectively increasing the cost of reproduction. Among plants of reproductive age, increased deer impact decreases the size-dependent probability of flowering and reduces reproductive consistency over time. This pattern in sex expression skews populations toward female-biased OSRs at low deer impact sites and male-biased OSRs at intermediate and high deer impact sites. While this shift toward a male-biased OSR may ameliorate pollen limitation, it also decreases the effective population size when coupled with increased asexual reproduction. The divergence of reproductive strategies and reduced lifetime fitness in response to indirect deer impacts illustrate the persistent long-term effects of overabundant herbivores on unpalatable understory perennials.
Collapse
|
19
|
Blossey B, Curtis P, Boulanger J, Dávalos A. Red oak seedlings as indicators of deer browse pressure: Gauging the outcome of different white-tailed deer management approaches. Ecol Evol 2019; 9:13085-13103. [PMID: 31871631 PMCID: PMC6912884 DOI: 10.1002/ece3.5729] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 08/19/2019] [Accepted: 09/15/2019] [Indexed: 01/10/2023] Open
Abstract
After decades of high deer populations, North American forests have lost much of their previous biodiversity. Any landscape-level recovery requires substantial reductions in deer herds, but modern societies and wildlife management agencies appear unable to devise appropriate solutions to this chronic ecological and human health crisis. We evaluated the effectiveness of fertility control and hunting in reducing deer impacts at Cornell University. We estimated spring deer populations and planted Quercus rubra seedlings to assess deer browse pressure, rodent attack, and other factors compromising seedling performance. Oak seedlings protected in cages grew well, but deer annually browsed ≥60% of unprotected seedlings. Despite female sterilization rates of >90%, the deer population remained stable. Neither sterilization nor recreational hunting reduced deer browse rates and neither appears able to achieve reductions in deer populations or their impacts. We eliminated deer sterilization and recreational hunting in a core management area in favor of allowing volunteer archers to shoot deer over bait, including at night. This resulted in a substantial reduction in the deer population and a linear decline in browse rates as a function of spring deer abundance. Public trust stewardship of North American landscapes will require a fundamental overhaul in deer management to provide for a brighter future, and oak seedlings may be a promising metric to assess success. These changes will require intense public debate and may require new approaches such as regulated commercial hunting, natural dispersal, or intentional release of important deer predators (e.g., wolves and mountain lions). Such drastic changes in deer management will be highly controversial, and at present, likely difficult to implement in North America. However, the future of our forest ecosystems and their associated biodiversity will depend on evidence to guide change in landscape management and stewardship.
Collapse
Affiliation(s)
- Bernd Blossey
- Department of Natural ResourcesCornell UniversityIthacaNYUSA
| | - Paul Curtis
- Department of Natural ResourcesCornell UniversityIthacaNYUSA
| | | | | |
Collapse
|
20
|
Release from Above- and Belowground Insect Herbivory Mediates Invasion Dynamics and Impact of an Exotic Plant. PLANTS 2019; 8:plants8120544. [PMID: 31779143 PMCID: PMC6963668 DOI: 10.3390/plants8120544] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 11/19/2019] [Accepted: 11/21/2019] [Indexed: 11/17/2022]
Abstract
The enemy-release hypothesis is one of the most popular but also most discussed hypotheses to explain invasion success. However, there is a lack of explicit, experimental tests of predictions of the enemy-release hypothesis (ERH), particularly regarding the effects of above- and belowground herbivory. Long-term studies investigating the relative effect of herbivores on invasive vs. native plant species within a community are still lacking. Here, we report on a long-term field experiment in an old-field community, invaded by Solidago canadensis s. l., with exclusion of above- and belowground insect herbivores. We monitored population dynamics of the invader and changes in the diversity and functioning of the plant community across eight years. Above- and belowground insects favoured the establishment of the invasive plant species and thereby increased biomass and decreased diversity of the plant community. Effects of invertebrate herbivores on population dynamics of S. canadensis appeared after six years and increased over time, suggesting that long-term studies are needed to understand invasion dynamics and consequences for plant community structure. We suggest that the release from co-evolved trophic linkages is of importance not only for the effect of invasive species on ecosystems, but also for the functioning of novel species assemblages arising from climate change.
Collapse
|
21
|
Lucero JE, Schaffner U, Asadi G, Bagheri A, Rajabov T, Callaway RM. Enemy release from the effects of generalist granivores can facilitate Bromus tectorum invasion in the Great Basin Desert. Ecol Evol 2019; 9:8490-8499. [PMID: 31410256 PMCID: PMC6686303 DOI: 10.1002/ece3.5314] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 04/17/2019] [Accepted: 05/02/2019] [Indexed: 11/17/2022] Open
Abstract
The enemy release hypothesis (ERH) of plant invasion asserts that natural enemies limit populations of invasive plants more strongly in native ranges than in non-native ranges. Despite considerable empirical attention, few studies have directly tested this idea, especially with respect to generalist herbivores. This knowledge gap is important because escaping the effects of generalists is a critical aspect of the ERH that may help explain successful plant invasions. Here, we used consumer exclosures and seed addition experiments to contrast the effects of granivorous rodents (an important guild of generalists) on the establishment of cheatgrass (Bromus tectorum) in western Asia, where cheatgrass is native, versus the Great Basin Desert, USA, where cheatgrass is exotic and highly invasive. Consistent with the ERH, rodent foraging reduced cheatgrass establishment by nearly 60% in western Asia but had no effect in the Great Basin. This main result corresponded with a region-specific foraging pattern: rodents in the Great Basin but not western Asia generally avoided seeds from cheatgrass relative to seeds from native competitors. Our results suggest that enemy release from the effects of an important guild of generalists may contribute to the explosive success of cheatgrass in the Great Basin. These findings corroborate classic theory on enemy release and expand our understanding of how generalists can influence the trajectory of exotic plant invasions.
Collapse
Affiliation(s)
- Jacob E. Lucero
- Division of Biological Sciences and the Institute on EcosystemsThe University of MontanaMissoulaMontana
- Department of BiologyYork UniversityTorontoOntarioCanada
| | | | - Ghorbanali Asadi
- Department of Agronomy, College of AgricultureFerdowsi University of MashhadMashhadIran
| | - Alireza Bagheri
- Department of Agronomy and Plant BreedingRazi UniversityKermanshahIran
| | - Toshpulot Rajabov
- Department of Botany and Plant PhysiologySamarkand State UniversitySamarkandUzbekistan
| | - Ragan M. Callaway
- Division of Biological Sciences and the Institute on EcosystemsThe University of MontanaMissoulaMontana
- Wildlife Biology ProgramThe University of MontanaMissoulaMontana
| |
Collapse
|
22
|
Stinson K, Carley L, Hancock L, Donohue K. Effects of maternal source and progeny microhabitat on natural selection and population dynamics in Alliaria petiolata. AMERICAN JOURNAL OF BOTANY 2019; 106:821-832. [PMID: 31162644 DOI: 10.1002/ajb2.1299] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 04/15/2019] [Indexed: 06/09/2023]
Abstract
PREMISE The success or failure of propagules in contrasting microhabitats may play a role in biological invasion. We tested for variation in demographic performance and phenotypic trait expression during invasion by Alliaria petiolata in different microhabitats. METHODS We performed a reciprocal transplant experiment with Alliaria petiolata from edge, intermediate, and forest understory microhabitats to determine the roles of the environment and maternal source on traits, fecundity, population growth rates (λ), and selection. RESULTS Observations of in situ populations show that edge populations had the highest density and reproductive output, and forest populations had the lowest. In experimental populations, population growth rates and reproductive output were highest in the edge, and the intermediate habitat had the lowest germination and juvenile survival. Traits exhibited phenotypic plasticity in response to microhabitat, but that plasticity was not adaptive. There were few effects of maternal source location on fitness components or traits. CONCLUSIONS Alliaria petiolata appears to be viable, or nearly so, in all three microhabitat types, with edge populations likely providing seed to the other microhabitats. The intermediate microhabitat may filter propagules at the seed stage, but discrepancies between in situ observations and experimental transplants preclude clear conclusions about the role of each microhabitat in niche expansion. However, edge microhabitats show the highest seed output in both analyses, suggesting that managing edge habitats might reduce spread to the forest understory.
Collapse
Affiliation(s)
- Kristina Stinson
- University of Massachusetts, Environmental Conservation, Amherst, MA, 01003, USA
- Harvard University, Harvard Forest, Petersham, MA, 01366, USA
| | - Lauren Carley
- Duke University Program in Ecology, Durham, NC, 27708, USA
- Duke University Biology Department, Durham, NC, 27708, USA
| | - Laura Hancock
- University of Massachusetts, Environmental Conservation, Amherst, MA, 01003, USA
- University of Massachusetts, Graduate Program in Organismic and Evolutionary Biology, Amherst, MA, 01003, USA
| | | |
Collapse
|
23
|
Anderson MD, Davis MA, Burke C, Dalrymple C, Ensley‐Field M, Lewanski A, Manning P, Moore Z, Morisawa R, Nguyen P, Pillar A, Dosch JJ. Comparison of the non‐native herb Alliaria petiolatawith dominant native herbs in microhabitats of a Midwestern forest. Ecosphere 2019. [DOI: 10.1002/ecs2.2660] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
| | - Mark A. Davis
- Biology Department Macalester College Saint Paul Minnesota USA
| | - Craig Burke
- Biology Department Macalester College Saint Paul Minnesota USA
| | - Cody Dalrymple
- Biology Department Macalester College Saint Paul Minnesota USA
| | | | - Alex Lewanski
- Biology Department Macalester College Saint Paul Minnesota USA
| | - Paul Manning
- Biology Department Macalester College Saint Paul Minnesota USA
| | - Zach Moore
- Biology Department Macalester College Saint Paul Minnesota USA
| | - Rina Morisawa
- Biology Department Macalester College Saint Paul Minnesota USA
| | - Phuong Nguyen
- Biology Department Macalester College Saint Paul Minnesota USA
| | - Allison Pillar
- Biology Department Macalester College Saint Paul Minnesota USA
| | - Jerald J. Dosch
- Biology Department Macalester College Saint Paul Minnesota USA
| |
Collapse
|
24
|
McCary MA, Zellner M, Wise DH. The role of plant-mycorrhizal mutualisms in deterring plant invasions: Insights from an individual-based model. Ecol Evol 2019; 9:2018-2030. [PMID: 30847089 PMCID: PMC6392346 DOI: 10.1002/ece3.4892] [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: 06/07/2018] [Revised: 11/17/2018] [Accepted: 12/07/2018] [Indexed: 11/07/2022] Open
Abstract
Understanding the factors that determine invasion success for non-native plants is crucial for maintaining global biodiversity and ecosystem functioning. One hypothesized mechanism by which many exotic plants can become invasive is through the disruption of key plant-mycorrhizal mutualisms, yet few studies have investigated how these disruptions can lead to invader success. We present an individual-based model to examine how mutualism strengths between a native plant (Impatiens capensis) and mycorrhizal fungus can influence invasion success for a widespread plant invader, Alliaria petiolata (garlic mustard). Two questions were investigated as follows: (a) How does the strength of the mutualism between the native I. capensis and a mycorrhizal fungus affect resistance (i.e., native plant maintaining >60% of final equilibrium plant density) to garlic mustard invasion? (b) Is there a non-linear relationship between initial garlic mustard density and invasiveness (i.e., garlic mustard representing >60% of final equilibrium plant density)? Our findings indicate that either low (i.e., facultative) or high (i.e., obligate) mutualism strengths between the native plant and mycorrhizal fungus were more likely to lead to garlic mustard invasiveness than intermediate levels, which resulted in higher resistance to garlic mustard invasion. Intermediate mutualism strengths allowed I. capensis to take advantage of increased fitness when the fungus was present but remained competitive enough to sustain high numbers without the fungus. Though strong mutualisms had the highest fitness without the invader, they proved most susceptible to invasion because the loss of the mycorrhizal fungus resulted in a reproductive output too low to compete with garlic mustard. Weak mutualisms were more competitive than strong mutualisms but still led to garlic mustard invasion. Furthermore, we found that under intermediate mutualism strengths, the initial density of garlic mustard (as a proxy for different levels of plant invasion) did not influence its invasion success, as high initial densities of garlic mustard did not lead to it becoming dominant. Our results indicate that plants that form weak or strong mutualisms with mycorrhizal fungi are most vulnerable to invasion, whereas intermediate mutualisms provide the highest resistance to an allelopathic invader.
Collapse
Affiliation(s)
- Matthew A. McCary
- Department of Biological SciencesUniversity of IllinoisChicagoIllinois
- Institute for Environmental Science and PolicyUniversity of IllinoisChicagoIllinois
- Present address:
Department of EntomologyUniversity of WisconsinMadisonWisconsin
| | - Moira Zellner
- Institute for Environmental Science and PolicyUniversity of IllinoisChicagoIllinois
- Department of Urban Planning and PolicyUniversity of IllinoisChicagoIllinois
| | - David H. Wise
- Department of Biological SciencesUniversity of IllinoisChicagoIllinois
- Institute for Environmental Science and PolicyUniversity of IllinoisChicagoIllinois
| |
Collapse
|
25
|
Heberling JM, Cassidy ST, Fridley JD, Kalisz S. Carbon gain phenologies of spring-flowering perennials in a deciduous forest indicate a novel niche for a widespread invader. THE NEW PHYTOLOGIST 2019; 221:778-788. [PMID: 30152089 DOI: 10.1111/nph.15404] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 07/22/2018] [Indexed: 05/22/2023]
Abstract
Strategies of herbaceous species in deciduous forests are often characterized by the timing of life history phases (e.g. emergence, flowering, leaf senescence) relative to overstory tree canopy closure. Although springtime photosynthesis is assumed to account for the majority of their annual carbon budgets, the 12-month photosynthetic trajectories of forest herbs have not been quantified. We measured the temporal dynamics of carbon assimilation for seven native herbaceous perennials and the biennial Alliaria petiolata, a widespread invader in eastern North American forests. We assessed the relative importance of spring, summer, and autumn to species-level annual carbon budgets. Spring-emerging species showed significant variation in carbon assimilation patterns. High spring irradiance before canopy closure accounted for 39-100% of species-level annual carbon assimilation, but summer and autumn accounted for large proportions of some species' carbon budgets (up to 58% and 19%, respectively). Alliaria was phenologically unique, taking advantage both autumn and spring irradiance. Although spring-emerging understory species are often expected to rely on early-season irradiance, our results highlight interspecific differences and the importance of mid-late season carbon gain. Phenological strategies of forest herbs are a continuum rather than discrete categories, and invasive species may follow strategies that are underrepresented in the native flora.
Collapse
Affiliation(s)
- J Mason Heberling
- Department of Ecology and Evolutionary Biology, The University of Tennessee, Knoxville, TN, 37996, USA
- Section of Botany, Carnegie Museum of Natural History, Pittsburgh, PA, 15213, USA
| | - Steven T Cassidy
- Department of Ecology and Evolutionary Biology, The University of Tennessee, Knoxville, TN, 37996, USA
| | - Jason D Fridley
- Department of Biology, Syracuse University, Syracuse, NY, 13244, USA
| | - Susan Kalisz
- Department of Ecology and Evolutionary Biology, The University of Tennessee, Knoxville, TN, 37996, USA
- Section of Botany, Carnegie Museum of Natural History, Pittsburgh, PA, 15213, USA
| |
Collapse
|
26
|
Differences in landscape drivers of garlic mustard invasion within and across ecoregions. Biol Invasions 2018. [DOI: 10.1007/s10530-018-1896-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
27
|
St Clair SB, O'Connor R, Gill R, McMillan B. Biotic resistance and disturbance: rodent consumers regulate post-fire plant invasions and increase plant community diversity. Ecology 2018; 97:1700-1711. [PMID: 27859155 DOI: 10.1002/ecy.1391] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 02/23/2016] [Indexed: 11/11/2022]
Abstract
Biotic resistance and disturbance are fundamental processes influencing plant invasion outcomes; however, the role of consumers in regulating the establishment and spread of plant invaders and how disturbance modifies biotic resistance by consumers is unclear. We document that fire in combination with experimental exclusion of rodent consumers shifted a native desert shrubland to a low-diversity, invasive annual grassland dominated by Bromus tectorum (cheatgrass). In contrast, burned plots with rodents present suppressed invasion by cheatgrass and developed into a more diverse forb community. Rodents created strong biotic resistance to the establishment of aggressive plant invaders likely through seed and seedling predation, which had cascading effects on plant competition and plant community diversity. Fire mediated its positive effects on plant invaders through native plant removal and by decreasing the abundance and diversity of the rodent community. The experimental disruption of plant and consumer-mediated biotic resistance of plant invaders using fire and rodent exclusion treatments provides strong evidence that native plants and rodents are important regulators of plant invasion dynamics and plant biodiversity in our study system. While rodents conferred strong resistance to invasion in our study system, fluctuations in rodent populations due to disturbance and climatic events may provide windows of opportunity for exotic plant species to escape biotic resistance by rodent consumers and initiate invasions.
Collapse
Affiliation(s)
- Samuel B St Clair
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, Utah, 84602, USA
| | - Rory O'Connor
- Department of Biology, Brigham Young University, Provo, Utah, 84602, USA
| | - Richard Gill
- Department of Biology, Brigham Young University, Provo, Utah, 84602, USA
| | - Brock McMillan
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, Utah, 84602, USA
| |
Collapse
|
28
|
Short-Term Vegetation Responses to Invasive Shrub Control Techniques for Amur Honeysuckle (Lonicera maackii [Rupr.] Herder). FORESTS 2018. [DOI: 10.3390/f9100607] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Invasive shrubs in forest understories threaten biodiversity and forest regeneration in the eastern United States. Controlling these extensive monotypic shrub thickets is a protracted process that slows the restoration of degraded forest land. Invasive shrub removal can be accelerated by using forestry mulching heads, but evidence from the western United States indicates that mulching heads can promote exotic species establishment and mulch deposition can reduce native plant species abundance. We compared the effectiveness of the mulching head and the “cut-stump” method for controlling the invasive shrub Amur honeysuckle (Lonicera maackii), as well as their impacts on native plant community recovery, in mixed-hardwood forests of Indiana. After two growing seasons, mulching head treatment resulted in greater L. maackii regrowth and regeneration. The recovery of native plant abundance and diversity following shrub removal did not differ between the two methods. However, mulch deposition was associated with increased abundance of garlic mustard (Alliaria petiolata), an invasive forb. Increasing mulching head treatment depth reduced L. maackii regrowth, but additional study is needed to determine how it affects plant community responses. The mulching head is a promising technique for invasive shrub control and investigating tradeoffs between reducing landscape-scale propagule pressure and increased local establishment will further inform its utility.
Collapse
|
29
|
Haines DF, Aylward JA, Frey SD, Stinson KA. Regional Patterns of Floristic Diversity and Composition in Forests Invaded by Garlic Mustard (Alliaria petiolata). Northeast Nat (Steuben) 2018. [DOI: 10.1656/045.025.0307] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Dustin F. Haines
- Department of Biology, University of Minnesota Duluth, Duluth, MN 55812
| | | | - Serita D. Frey
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH 03824
| | - Kristina A. Stinson
- Department of Environmental Conservation, University of Massachusetts Amherst, Amherst, MA 01003
| |
Collapse
|
30
|
McGraw JB, Chandler JL. Demographic hallmarks of an overbrowsed population state in American ginseng. Glob Ecol Conserv 2018. [DOI: 10.1016/j.gecco.2018.e00435] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
31
|
Gill RA, O'Connor RC, Rhodes A, Bishop TBB, Laughlin DC, St Clair SB. Niche opportunities for invasive annual plants in dryland ecosystems are controlled by disturbance, trophic interactions, and rainfall. Oecologia 2018; 187:755-765. [PMID: 29736861 DOI: 10.1007/s00442-018-4137-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 04/05/2018] [Indexed: 10/17/2022]
Abstract
Resource availability and biotic interactions control opportunities for the establishment and expansion of invasive species. Studies on biotic resistance to plant invasions have typically focused on competition and occasionally on herbivory, while resource-oriented studies have focused on water or nutrient pulses. Through synthesizing these approaches, we identify conditions that create invasion opportunities. In a nested fully factorial experiment, we examined how chronic alterations in water availability and rodent density influenced the density of invasive species in both the Mojave Desert and the Great Basin Desert after fire. We used structural equation modeling to examine the direct and mediated effects controlling the density of invasives in both deserts. In the first 2 years after our controlled burn in the Great Basin, we observed that fire had a direct effect on increasing the invasive forb Halogeton glomeratus as well as a mediated effect through reducing rodent densities and herbivory. 4 years after the burn, the invasive annual grass Bromus tectorum was suppressing Halogeton glomeratus in mammal exclusion plots. There was a clear transition from years where invasives were controlled by disturbance and trophic interactions to years were resource availability and competition controlled invasive density. Similarly, in the Mojave Desert we observed a strong early influence of trophic processes on invasives, with Schismus arabicus benefitted by rodents and Bromus rubens negatively influenced by rodents. In the Mojave Desert, post-fire conditions became less important in controlling the abundance of invasives over time, while Bromus rubens was consistently benefitted by increases in fall rainfall.
Collapse
Affiliation(s)
- Richard A Gill
- Department of Biology, Brigham Young University, Provo, UT, 84602, USA.
| | - Rory C O'Connor
- Department of Biology, Brigham Young University, Provo, UT, 84602, USA.,Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| | - Aaron Rhodes
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, UT, 84602, USA
| | - Tara B B Bishop
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, UT, 84602, USA
| | - Daniel C Laughlin
- Environmental Research Institute and School of Science, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
| | - Samuel B St Clair
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, UT, 84602, USA
| |
Collapse
|
32
|
Loebach CA, Anderson RC. Measuring short distance dispersal of Alliaria petiolata and determining potential long distance dispersal mechanisms. PeerJ 2018; 6:e4477. [PMID: 29576955 PMCID: PMC5857352 DOI: 10.7717/peerj.4477] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 02/19/2018] [Indexed: 12/02/2022] Open
Abstract
Introduction Alliaria petiolata, an herbaceous plant, has invaded woodlands in North America. Its ecology has been thoroughly studied, but an overlooked aspect of its biology is seed dispersal distances and mechanisms. We measured seed dispersal distances in the field and tested if epizoochory is a potential mechanism for long-distance seed dispersal. Methods Dispersal distances were measured by placing seed traps in a sector design around three seed point sources, which consisted of 15 second-year plants transplanted within a 0.25 m radius circle. Traps were placed at intervals ranging from 0.25–3.25 m from the point source. Traps remained in the field until a majority of seeds were dispersed. Eight probability density functions were fitted to seed trap counts via maximum likelihood. Epizoochory was tested as a potential seed dispersal mechanism for A. petiolata through a combination of field and laboratory experiments. To test if small mammals transport A. petiolata seeds in their fur, experimental blocks were placed around dense A. petiolata patches. Each block contained a mammal inclusion treatment (MIT) and control. The MIT consisted of a wood-frame (31 × 61× 31 cm) covered in wire mesh, except for the two 31 × 31 cm ends, placed over a germination tray filled with potting soil. A pan filled with bait was placed in the center of the tray. The control frame (11 × 31 × 61 cm) was placed over a germination tray and completely covered in wire mesh to exclude animal activity. Treatments were in the field for peak seed dispersal. In March, trays were moved to a greenhouse and A. petiolata seedlings were counted and then compared between treatments. To determine if A. petiolata seeds attach to raccoon (Procyon lotor) and white-tailed deer (Odocoileus virginianus) fur, wet and dry seeds were dropped onto wet and dry fur. Furs were rotated 180 degrees and the seeds that remained attached were counted. To measure seed retention, seeds were dropped on furs and rotated as before, then the furs were agitated for one hour. The seeds retained in the fur were counted. Results For the seed dispersal experiment, the 2Dt function provided the best fit and was the most biologically meaningful. It predicted that seed density rapidly declined with distance from the point source. Mean dispersal distance was 0.52 m and 95% of seeds dispersed within 1.14 m. The epizoochory field experiment showed increased mammal activity and A. petiolata seedlings in germination trays of the MIT compared to control. Laboratory studies showed 3–26% of seeds were attached and retained by raccoon and deer fur. Retention significantly increased if either seed or fur were wet (57–98%). Discussion Without animal seed vectors, most seeds fall within a short distance of the seed source; however, long distance dispersal may be accomplished by epizoochory. Our data are consistent with A. petiolata’s widespread distribution and development of dense clusters of the species in invaded areas.
Collapse
Affiliation(s)
- Christopher A Loebach
- School of Biological Sciences, Illinois State University, Normal, IL, United States of America
| | - Roger C Anderson
- School of Biological Sciences, Illinois State University, Normal, IL, United States of America
| |
Collapse
|
33
|
Smith-Ramesh LM. Predators in the plant-soil feedback loop: aboveground plant-associated predators may alter the outcome of plant-soil interactions. Ecol Lett 2018. [PMID: 29516652 DOI: 10.1111/ele.12931] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Plant-soil feedback (PSF) can structure plant communities, promoting coexistence (negative PSF) or monodominance (positive PSF). At higher trophic levels, predators can alter plant community structure by re-allocating resources within habitats. When predator and plant species are spatially associated, predators may alter the outcome of PSF. Here, I explore the influence of plant-associated predators on PSF using a generalised cellular automaton model that tracks nutrients, plants, herbivores and predators. I explore key contingencies in plant-predator associations such as whether predators associate with live vs. senesced vegetation. Results indicate that plant-associated predators shift PSF to favour the host plant when predators colonise live vegetation, but the outcome of PSF will depend upon plant dispersal distance when predators colonise dead vegetation. I apply the model to two spider-associated invasive plants, finding that spider predators should shift PSF dynamics in a way that inhibits invasion by one forest invader, but exacerbates invasion by another.
Collapse
Affiliation(s)
- Lauren M Smith-Ramesh
- National Institute for Mathematical and Biological Synthesis, 1122 Volunteer Blvd., Knoxville, TN, 37996, USA
| |
Collapse
|
34
|
Averill KM, Mortensen DA, Smithwick EAH, Kalisz S, McShea WJ, Bourg NA, Parker JD, Royo AA, Abrams MD, Apsley DK, Blossey B, Boucher DH, Caraher KL, DiTommaso A, Johnson SE, Masson R, Nuzzo VA. A regional assessment of white-tailed deer effects on plant invasion. AOB PLANTS 2018; 10:plx047. [PMID: 29340133 PMCID: PMC5761582 DOI: 10.1093/aobpla/plx047] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 09/01/2017] [Indexed: 06/07/2023]
Abstract
Herbivores can profoundly influence plant species assembly, including plant invasion, and resulting community composition. Population increases of native herbivores, e.g. white-tailed deer (Odocoileus virginianus), combined with burgeoning plant invasions raise concerns for native plant diversity and forest regeneration. While individual researchers typically test for the impact of deer on plant invasion at a few sites, the overarching influence of deer on plant invasion across regional scales is unclear. We tested the effects of deer on the abundance and diversity of introduced and native herbaceous and woody plants across 23 white-tailed deer research sites distributed across the east-central and north-eastern USA and representing a wide range of deer densities and invasive plant abundance and identity. Deer access/exclusion or deer population density did not affect introduced plant richness or community-level abundance. Native and total plant species richness, abundance (cover and stem density) and Shannon diversity were lower in deer-access vs. deer-exclusion plots. Among deer-access plots, native species richness, native and total cover, and Shannon diversity (cover) declined as deer density increased. Deer access increased the proportion of introduced species cover (but not of species richness or stem density). As deer density increased, the proportion of introduced species richness, cover and stem density all increased. Because absolute abundance of introduced plants was unaffected by deer, the increase in proportion of introduced plant abundance is likely an indirect effect of deer reducing native cover. Indicator species analysis revealed that deer access favoured three introduced plant species, including Alliaria petiolata and Microstegium vimineum, as well as four native plant species. In contrast, deer exclusion favoured three introduced plant species, including Lonicera japonica and Rosa multiflora, and 15 native plant species. Overall, native deer reduced community diversity, lowering native plant richness and abundance, and benefited certain invasive plants, suggesting pervasive impacts of this keystone herbivore on plant community composition and ecosystem services in native forests across broad swathes of the eastern USA.
Collapse
Affiliation(s)
- Kristine M Averill
- Ecology Intercollege Graduate Degree Program, The Pennsylvania State University, University Park, PA, USA
- Department of Plant Sciences, The Pennsylvania State University, University Park, PA, USA
| | - David A Mortensen
- Ecology Intercollege Graduate Degree Program, The Pennsylvania State University, University Park, PA, USA
- Department of Plant Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Erica A H Smithwick
- Ecology Intercollege Graduate Degree Program, The Pennsylvania State University, University Park, PA, USA
- Department of Geography, The Pennsylvania State University, University Park, PA, USA
| | - Susan Kalisz
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, USA
| | - William J McShea
- Smithsonian Conservation Biology Institute, Front Royal, VA, USA
| | - Norman A Bourg
- Smithsonian Conservation Biology Institute, Front Royal, VA, USA
| | - John D Parker
- Smithsonian Environmental Research Center, Edgewater, MD, USA
| | - Alejandro A Royo
- United States Department of Agriculture Forest Service, Northern Research Station, Irvine, PA, USA
| | - Marc D Abrams
- Ecology Intercollege Graduate Degree Program, The Pennsylvania State University, University Park, PA, USA
- Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, PA, USA
| | - David K Apsley
- Department of Extension, The Ohio State University, Jackson, OH, USA
| | - Bernd Blossey
- Department of Natural Resources, Cornell University, Ithaca, NY, USA
| | | | - Kai L Caraher
- Department of Biology, Hood College, Frederick, MD, USA
| | | | - Sarah E Johnson
- Ecology Intercollege Graduate Degree Program, The Pennsylvania State University, University Park, PA, USA
- Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, PA, USA
| | - Robert Masson
- National Park Service, Morristown National Historical Park, Morristown, NJ, USA
| | | |
Collapse
|
35
|
Rivest S, Vellend M. Herbivory and pollen limitation at the upper elevational range limit of two forest understory plants of eastern North America. Ecol Evol 2018; 8:892-903. [PMID: 29375763 PMCID: PMC5773324 DOI: 10.1002/ece3.3397] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 07/31/2017] [Accepted: 08/03/2017] [Indexed: 11/10/2022] Open
Abstract
Studies of species' range limits focus most often on abiotic factors, although the strength of biotic interactions might also vary along environmental gradients and have strong demographic effects. For example, pollinator abundance might decrease at range limits due to harsh environmental conditions, and reduced plant density can reduce attractiveness to pollinators and increase or decrease herbivory. We tested for variation in the strength of pollen limitation and herbivory by ungulates along a gradient leading to the upper elevational range limits of Trillium erectum (Melanthiaceae) and Erythronium americanum (Liliaceae) in Mont Mégantic National Park, Québec, Canada. In T. erectum, pollen limitation was higher at the range limit, but seed set decreased only slightly with elevation and only in one of two years. In contrast, herbivory of T. erectum increased from <10% at low elevations to >60% at the upper elevational range limit. In E. americanum, we found no evidence of pollen limitation despite a significant decrease in seed set with elevation, and herbivory was low across the entire gradient. Overall, our results demonstrate the potential for relatively strong negative interactions (herbivory) and weak positive interactions (pollination) at plant range edges, although this was clearly species specific. To the extent that these interactions have important demographic consequences-highly likely for herbivory on Trillium, based on previous studies-such interactions might play a role in determining plant species' range limits along putatively climatic gradients.
Collapse
Affiliation(s)
- Sébastien Rivest
- Département de BiologieUniversité de SherbrookeSherbrookeQCCanada
| | - Mark Vellend
- Département de BiologieUniversité de SherbrookeSherbrookeQCCanada
| |
Collapse
|
36
|
Williams SC, Linske MA, Ward JS. Long-Term Effects of Berberis thunbergii (Ranunculales: Berberidaceae) Management on Ixodes scapularis (Acari: Ixodidae) Abundance and Borrelia burgdorferi (Spirochaetales: Spirochaetaceae) Prevalence in Connecticut, USA. ENVIRONMENTAL ENTOMOLOGY 2017; 46:1329-1338. [PMID: 29029041 DOI: 10.1093/ee/nvx146] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Indexed: 06/07/2023]
Abstract
Japanese barberry (Berberis thunbergii de Candolle; Ranunculales: Berberidaceae) is an exotic invasive shrub that escaped cultivation in the United States and is now permanently established in many eastern and midwestern states. This study examined the long-term impacts of Japanese barberry management on blacklegged tick (Ixodes scapularis Say; Acari: Ixodidae) abundances and associated prevalence of Borrelia burgdorferi (Johnson, Schmid, Hyde, Steigerwalt, and Brenner; Spirochaetales: Spirochaetaceae), the etiologic agent of Lyme disease. At six locations across Connecticut, adult I. scapularis were sampled for up to 10 yr. At each location, we sampled an area where barberry infestations were unmanipulated, adjacent areas where barberry was virtually nonexistent, and areas where barberry was managed utilizing a variety of techniques. Barberry management reduced B. burgdorferi-infected adult I. scapularis (BBIAIS) abundances (191/ha ± 64 SE) over 6 yr to statistically indifferent from that of no barberry areas (140/ha ± 47 SE; P = 0.080) and significantly less than intact barberry stands (458/ha ± 80 SE; P = 0.026). Over 9 yr, BBIAIS abundances in managed barberry remained lower than intact barberry stands (P = 0.037), but increased to be significantly greater than no barberry areas (P = 0.007) as cover increased over time. Longer-term data further document that Japanese barberry infestations are favorable habitat for I. scapularis. Control of Japanese barberry and other invasives should be at least on a 5-yr rotation to maintain low levels of invasive cover and eliminate humidity refugia to expose juvenile I. scapularis to more hostile environmental conditions in the interest of public health.
Collapse
Affiliation(s)
- Scott C Williams
- Department of Forestry and Horticulture, The Connecticut Agricultural Experiment Station, New Haven, CT 06504
- Center for Vector Biology & Zoonotic Diseases, The Connecticut Agricultural Experiment Station, New Haven, CT 06504
| | - Megan A Linske
- Center for Vector Biology & Zoonotic Diseases, The Connecticut Agricultural Experiment Station, New Haven, CT 06504
- Department of Natural Resources and the Environment, College of Agriculture, Health, and Natural Resources, University of Connecticut, Storrs, CT 06269-4087
| | - Jeffrey S Ward
- Department of Forestry and Horticulture, The Connecticut Agricultural Experiment Station, New Haven, CT 06504
| |
Collapse
|
37
|
|
38
|
Blossey B, Gorchov DL. Introduction to the Special Issue: Ungulates and invasive species: quantifying impacts and understanding interactions. AOB PLANTS 2017; 9:plx063. [PMID: 29302303 PMCID: PMC5739040 DOI: 10.1093/aobpla/plx063] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 11/07/2017] [Indexed: 06/07/2023]
Abstract
White-tailed deer are emblematic ungulates that, due to anthropogenic modification of landscapes, currently occur at elevated densities. Elevated deer densities often co-occur with non-native plants, but it is not known if plant invasions are a consequence of deer impacts or occur independent of deer impacts on ecosystems, or whether these two stressors are synergistic. A colloquium on 'Interactions of white-tailed deer and invasive plants in forests of eastern North America' explored these topics at the 2016 annual meeting of the Botanical Society of America. Nine of those presentations are published in this special issue of AoB PLANTS.
Collapse
Affiliation(s)
- Bernd Blossey
- Department of Natural Resources, Fernow Hall, Cornell University, Ithaca, NY, USA
| | | |
Collapse
|
39
|
Inderjit, Catford JA, Kalisz S, Simberloff D, Wardle DA. A framework for understanding human‐driven vegetation change. OIKOS 2017. [DOI: 10.1111/oik.04587] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Inderjit
- Dept of Environmental Studies Centre for Environmental Management of Degraded Ecosystems (CEMDE), Univ. of Delhi Delhi India
| | - Jane A. Catford
- Biological Sciences Univ. of Southampton, Southampton, UK, and: School of BioSciences, The Univ. of Melbourne Victoria Australia
| | - Susan Kalisz
- Dept of Ecology and Evolutionary Biology Univ. of Tennessee Knoxville TN USA
| | - Daniel Simberloff
- Dept of Ecology and Evolutionary Biology Univ. of Tennessee Knoxville TN USA
| | - David A. Wardle
- Dept of Forest Ecology and Management Swedish Univ. of Agricultural Sciences Umeå Sweden
- Asian School of the Environment, Nanyang Technological Univ. Singapore
| |
Collapse
|
40
|
Liebhold AM, Brockerhoff EG, Kalisz S, Nuñez MA, Wardle DA, Wingfield MJ. Biological invasions in forest ecosystems. Biol Invasions 2017. [DOI: 10.1007/s10530-017-1458-5] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|
41
|
Blossey B, Dávalos A, Nuzzo V. An indicator approach to capture impacts of white-tailed deer and other ungulates in the presence of multiple associated stressors. AOB PLANTS 2017; 9:plx034. [PMID: 28894567 PMCID: PMC5585856 DOI: 10.1093/aobpla/plx034] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 07/20/2017] [Indexed: 06/07/2023]
Abstract
Management of ungulates is contested ground that lacks stakeholder agreement on desirable population sizes and management approaches. Unfortunately, we often miss information about extent of local impacts, for example on plant communities, to guide management decisions. Typical vegetation impact assessments like the woody browse index do not assess herbaceous plants, and differences in browse severity can be a function of deer density, deer legacy effects, localized deer feeding preferences and/or differences in plant community composition. Furthermore, in heavily affected areas, few remnant plants may remain for assessments. We used a sentinel approach to assess impact of white-tailed deer (Odocoileus virginianus), rodent attack, invasive earthworms and three invasive plants on survival and growth of 3-month-old red oak (Quercus rubra) individuals. We planted cohorts in 2010 and 2011 into deer accessible and fenced 30 × 30 m plots at 12 forests in New York State. We found year and site-specific effects with high deer herbivory of unprotected individuals (70-90 % of oaks browsed by deer versus none in fenced areas) far exceeding importance of rodent attacks. Oaks planted at low earthworm density sites were at significantly higher risk of being browsed compared with oaks at high earthworm density sites, but there was no detectable negative effect of invasive plants. Surviving oaks grew (~2 cm per year) under forest canopy cover, but only when fenced. We consider planting of oak or other woody or herbaceous sentinels to assess deer browse pressure a promising method to provide quantifiable evidence for deer impacts and to gauge success of different management techniques. The strength of this approach is that typical problems associated with multiple stressor impacts can be avoided, areas devoid of forest floor vegetation but under heavy deer browse pressure can still be assessed and the method can be implemented by non-specialists. Implementation of regular assessments can guide ungulate management based on meaningful evidence.
Collapse
Affiliation(s)
- Bernd Blossey
- Department of Natural Resources, Fernow Hall, Cornell University, Ithaca, NY 14853, USA
| | - Andrea Dávalos
- Department of Natural Resources, Fernow Hall, Cornell University, Ithaca, NY 14853, USA
| | - Victoria Nuzzo
- Natural Area Consultants, 1 West Hill School Road, Richford, NY 13835, USA
| |
Collapse
|
42
|
Nuzzo V, Dávalos A, Blossey B. Assessing plant community composition fails to capture impacts of white-tailed deer on native and invasive plant species. AOB PLANTS 2017; 9:plx026. [PMID: 28775829 PMCID: PMC5534022 DOI: 10.1093/aobpla/plx026] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 06/06/2017] [Indexed: 06/07/2023]
Abstract
Excessive herbivory can have transformative effects on forest understory vegetation, converting diverse communities into depauperate ones, often with increased abundance of non-native plants. White-tailed deer are a problematic herbivore throughout much of eastern North America and alter forest understory community structure. Reducing (by culling) or eliminating (by fencing) deer herbivory is expected to return understory vegetation to a previously diverse condition. We examined this assumption from 1992 to 2006 at Fermilab (Batavia, IL) where a cull reduced white-tailed deer (Odocoileus virginianus) abundance in 1998/1999 by 90 % from 24.6 to 2.5/km2, and at West Point, NY, where we assessed interactive effects of deer, earthworms, and invasive plants using 30 × 30 m paired fenced and open plots in 12 different forests from 2009 to 2012. We recorded not only plant community responses (species presence and cover) within 1 m2 quadrats, but also responses of select individual species (growth, reproduction). At Fermilab, introduced Alliaria petiolata abundance initially increased as deer density increased, but then declined after deer reduction. The understory community responded to the deer cull by increased cover, species richness and height, and community composition changed but was dominated by early successional native forbs. At West Point plant community composition was affected by introduced earthworm density but not deer exclusion. Native plant cover increased and non-native plant cover decreased in fenced plots, thus keeping overall plant cover similar. At both sites native forb cover increased in response to deer reduction, but the anticipated response of understory vegetation failed to materialize at the community level. Deer-favoured forbs (Eurybia divaricata, Maianthemum racemosum, Polygonatum pubescens and Trillium recurvatum) grew taller and flowering probability increased in the absence of deer. Plant community monitoring fails to capture initial and subtle effects of reduced or even cessation of deer browse on browse sensitive species. Measuring responses of individual plants (growth, flowering and reproductive success) provides a more sensitive and powerful assessment of forest understory responses to deer management.
Collapse
Affiliation(s)
- Victoria Nuzzo
- Natural Area Consultants, 1 West Hill School Road, Richford, NY 13835, USA
| | - Andrea Dávalos
- Department of Natural Resources, 206 Fernow Hall, Cornell University, Ithaca, NY 14853, USA
| | - Bernd Blossey
- Department of Natural Resources, 206 Fernow Hall, Cornell University, Ithaca, NY 14853, USA
| |
Collapse
|
43
|
Wavrek M, Heberling JM, Fei S, Kalisz S. Herbaceous invaders in temperate forests: a systematic review of their ecology and proposed mechanisms of invasion. Biol Invasions 2017. [DOI: 10.1007/s10530-017-1456-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
44
|
The influence of time since introduction on the population growth of introduced species and the consequences for management. POPUL ECOL 2017. [DOI: 10.1007/s10144-017-0581-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
45
|
Erickson DL, Reed E, Ramachandran P, Bourg NA, McShea WJ, Ottesen A. Reconstructing a herbivore's diet using a novel rbcL DNA mini-barcode for plants. AOB PLANTS 2017; 9:plx015. [PMID: 28533898 PMCID: PMC5434754 DOI: 10.1093/aobpla/plx015] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 03/28/2017] [Accepted: 04/13/2017] [Indexed: 05/05/2023]
Abstract
Next Generation Sequencing and the application of metagenomic analyses can be used to answer questions about animal diet choice and study the consequences of selective foraging by herbivores. The quantification of herbivore diet choice with respect to native versus exotic plant species is particularly relevant given concerns of invasive species establishment and their effects on ecosystems. While increased abundance of white-tailed deer (Odocoileus virginianus) appears to correlate with increased incidence of invasive plant species, data supporting a causal link is scarce. We used a metabarcoding approach (PCR amplicons of the plant rbcL gene) to survey the diet of white-tailed deer (fecal samples), from a forested site in Warren County, Virginia with a comprehensive plant species inventory and corresponding reference collection of plant barcode and chloroplast sequences. We sampled fecal pellet piles and extracted DNA from 12 individual deer in October 2014. These samples were compared to a reference DNA library of plant species collected within the study area. For 72 % of the amplicons, we were able to assign taxonomy at the species level, which provides for the first time-sufficient taxonomic resolution to quantify the relative frequency at which native and exotic plant species are being consumed by white-tailed deer. For each of the 12 individual deer we collected three subsamples from the same fecal sample, resulting in sequencing 36 total samples. Using Qiime, we quantified the plant DNA found in all 36 samples, and found that variance within samples was less than variance between samples (F = 1.73, P = 0.004), indicating additional subsamples may not be necessary. Species level diversity ranged from 60 to 93 OTUs per individual and nearly 70 % of all plant sequences recovered were from native plant species. The number of species detected did reduce significantly (range 4-12) when we excluded species whose OTU composed <1 % of each sample's total. When compared to the abundance of native and non-natives plants inventoried in the local community, our results support the observation that white-tailed deer have strong foraging preferences, but these preferences were not consistent for species in either class. Deer forage behaviour may favour some exotic species, but not all.
Collapse
Affiliation(s)
- David L. Erickson
- Molecular Methods and Subtyping Branch, Division of Microbiology, Centre for Food Safety and Applied Nutrition (CFSAN), FDA, 5001 Campus Drive, College Park, ML 20740, USA
| | - Elizabeth Reed
- Molecular Methods and Subtyping Branch, Division of Microbiology, Centre for Food Safety and Applied Nutrition (CFSAN), FDA, 5001 Campus Drive, College Park, ML 20740, USA
| | - Padmini Ramachandran
- Molecular Methods and Subtyping Branch, Division of Microbiology, Centre for Food Safety and Applied Nutrition (CFSAN), FDA, 5001 Campus Drive, College Park, ML 20740, USA
| | - Norman A. Bourg
- U.S. Geological Survey, National Research Program - Eastern Branch, 12201 Sunrise Valley Drive, MS 430, Reston, VA 20192, USA
| | - William J. McShea
- Smithsonian Conservation Biology Institute, National Zoological Park, 1500 Remount Road, Front Royal, VA 22630, USA
| | - Andrea Ottesen
- Molecular Methods and Subtyping Branch, Division of Microbiology, Centre for Food Safety and Applied Nutrition (CFSAN), FDA, 5001 Campus Drive, College Park, ML 20740, USA
| |
Collapse
|
46
|
Heckman RW, Halliday FW, Wilfahrt PA, Mitchell CE. Effects of native diversity, soil nutrients, and natural enemies on exotic invasion in experimental plant communities. Ecology 2017; 98:1409-1418. [PMID: 28273331 DOI: 10.1002/ecy.1796] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 02/08/2017] [Accepted: 02/16/2017] [Indexed: 11/05/2022]
Abstract
Many factors can promote exotic plant success. Three of these factors-greater pressure from natural enemies on natives, increased soil nutrient supply, and low native species richness-may interact during invasions. To test for independent and interactive effects of these drivers, we planted herbaceous perennial communities at two levels of native richness (monocultures and five-species polycultures). We then factorially manipulated soil nutrient supply and access to these communities by aboveground foliar enemies (fungal pathogens and insect herbivores), and allowed natural colonization to proceed for four years. We predicted that nutrient addition would increase exotic success, while enemy exclusion and increasing native richness would reduce exotic success. Additionally, we expected that enemy exclusion would reduce the benefits of nutrient addition to exotic species most in species-poor communities, and that this effect would be weaker in species-rich communities. In total, we found no evidence that nutrient supply, enemy access, and native richness interacted to influence exotic success. Furthermore, native richness had no effect on exotic success. Instead, nutrient addition increased, and enemy exclusion decreased, exotic success independently. As predicted, enemy exclusion reduced exotic success, primarily by slowing the decline in abundance of planted native species. Together, these results demonstrate that multiple drivers of exotic success can act independently within a single system.
Collapse
Affiliation(s)
- Robert W Heckman
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina, 27599, USA
| | - Fletcher W Halliday
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina, 27599, USA
| | - Peter A Wilfahrt
- Curriculum for the Environment and Ecology, University of North Carolina, Chapel Hill, North Carolina, 27599, USA
| | - Charles E Mitchell
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina, 27599, USA.,Curriculum for the Environment and Ecology, University of North Carolina, Chapel Hill, North Carolina, 27599, USA
| |
Collapse
|
47
|
Elasticity of population growth with respect to the intensity of biotic or abiotic driving factors. Ecology 2017; 98:1016-1025. [DOI: 10.1002/ecy.1687] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 10/26/2016] [Accepted: 11/15/2016] [Indexed: 11/07/2022]
|
48
|
Climate change both facilitates and inhibits invasive plant ranges in New England. Proc Natl Acad Sci U S A 2017; 114:E3276-E3284. [PMID: 28348212 DOI: 10.1073/pnas.1609633114] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Forecasting ecological responses to climate change, invasion, and their interaction must rely on understanding underlying mechanisms. However, such forecasts require extrapolation into new locations and environments. We linked demography and environment using experimental biogeography to forecast invasive and native species' potential ranges under present and future climate in New England, United States to overcome issues of extrapolation in novel environments. We studied two potentially nonequilibrium invasive plants' distributions, Alliaria petiolata (garlic mustard) and Berberis thunbergii (Japanese barberry), each paired with their native ecological analogs to better understand demographic drivers of invasions. Our models predict that climate change will considerably reduce establishment of a currently prolific invader (A. petiolata) throughout New England driven by poor demographic performance in warmer climates. In contrast, invasion of B. thunbergii will be facilitated because of higher growth and germination in warmer climates, with higher likelihood to establish farther north and in closed canopy habitats in the south. Invasion success is in high fecundity for both invasive species and demographic compensation for Apetiolata relative to native analogs. For A. petiolata, simulations suggest that eradication efforts would require unrealistic efficiency; hence, management should focus on inhibiting spread into colder, currently unoccupied areas, understanding source-sink dynamics, and understanding community dynamics should A. petiolata (which is allelopathic) decline. Our results-based on considerable differences with correlative occurrence models typically used for such biogeographic forecasts-suggest the urgency of incorporating mechanism into range forecasting and invasion management to understand how climate change may alter current invasion patterns.
Collapse
|
49
|
Schneider S, Steeves R, Newmaster S, MacDougall AS. Selective plant foraging and the top-down suppression of native diversity in a restored prairie. J Appl Ecol 2017. [DOI: 10.1111/1365-2664.12886] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Stefan Schneider
- Department of Integrative Biology; University of Guelph; Guelph ON N1G2W1 Canada
| | - Royce Steeves
- Department of Integrative Biology; University of Guelph; Guelph ON N1G2W1 Canada
| | - Steve Newmaster
- Department of Integrative Biology; University of Guelph; Guelph ON N1G2W1 Canada
| | - Andrew S. MacDougall
- Department of Integrative Biology; University of Guelph; Guelph ON N1G2W1 Canada
| |
Collapse
|
50
|
Ender CL, Christian CE, Cushman JH. Native herbivores and environmental heterogeneity as mediators of an exotic grass invasion. Ecol Evol 2017; 7:1561-1571. [PMID: 28261465 PMCID: PMC5330880 DOI: 10.1002/ece3.2727] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 12/07/2016] [Accepted: 12/18/2016] [Indexed: 11/23/2022] Open
Abstract
Given that many exotic plant species throughout the world are having large ecological and economic effects, it is vital to understand the forces that mediate their success in novel landscapes. Both native herbivores and recipient ecosystems can have substantial effects on the performance of exotic plant species, and may interact with each other or vary in their effects over time. Unfortunately, few studies have evaluated the importance of these kinds of context-dependent effects. Here, we use a 17-year-old exclosure experiment stratified across a coastal grassland in northern California to address the relative importance of a reintroduced mammalian herbivore, tule elk (Cervus canadensis nannodes), and environmental heterogeneity in mediating the growth, abundance, and recruitment of a problematic grass invader, Holcus lanatus. We found that elk reduced Holcus abundance, aboveground biomass, percent cover, frequency, and seedling recruitment, but that these effects often varied among habitat types, with effects being greater in open grasslands than shrub-dominated grasslands. The performance of Holcus populations also varied significantly among habitat types, with the invader usually having the greatest success in Baccharis-dominated grasslands. Our results suggest that environmental heterogeneity had much greater influence on Holcus success than elk, and that these effects were due largely to soil pH and moisture. The negative effects of elk on Holcus appeared after 4 years and did not intensify after an additional 13 years. Furthermore, despite their negative effects, these prominent herbivores did not prevent the spread of Holcus into previously uninvaded areas. Our research highlights the importance of assessing the individual and interactive effects of native herbivores and environmental heterogeneity on the success of invasive, exotic plant species. It emphasizes the reality that the negative effects of herbivores on exotic plant species will often vary across heterogeneous landscapes and may be insufficient to prevent the expansion of these invaders.
Collapse
Affiliation(s)
- Cody L. Ender
- Department of BiologySonoma State UniversityRohnert ParkCAUSA
| | - Caroline E. Christian
- Department of Environmental Studies & PlanningSonoma State UniversityRohnert ParkCAUSA
| | - J. Hall Cushman
- Department of BiologySonoma State UniversityRohnert ParkCAUSA
| |
Collapse
|