1
|
Moore JH, Gibson L, Amir Z, Chanthorn W, Ahmad AH, Jansen PA, Mendes CP, Onuma M, Peres CA, Luskin MS. The rise of hyperabundant native generalists threatens both humans and nature. Biol Rev Camb Philos Soc 2023; 98:1829-1844. [PMID: 37311559 DOI: 10.1111/brv.12985] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 05/26/2023] [Accepted: 05/30/2023] [Indexed: 06/15/2023]
Abstract
In many disturbed terrestrial landscapes, a subset of native generalist vertebrates thrives. The population trends of these disturbance-tolerant species may be driven by multiple factors, including habitat preferences, foraging opportunities (including crop raiding or human refuse), lower mortality when their predators are persecuted (the 'human shield' effect) and reduced competition due to declines of disturbance-sensitive species. A pronounced elevation in the abundance of disturbance-tolerant wildlife can drive numerous cascading impacts on food webs, biodiversity, vegetation structure and people in coupled human-natural systems. There is also concern for increased risk of zoonotic disease transfer to humans and domestic animals from wildlife species with high pathogen loads as their abundance and proximity to humans increases. Here we use field data from 58 landscapes to document a supra-regional phenomenon of the hyperabundance and community dominance of Southeast Asian wild pigs and macaques. These two groups were chosen as prime candidates capable of reaching hyperabundance as they are edge adapted, with gregarious social structure, omnivorous diets, rapid reproduction and high tolerance to human proximity. Compared to intact interior forests, population densities in degraded forests were 148% and 87% higher for wild boar and macaques, respectively. In landscapes with >60% oil palm coverage, wild boar and pig-tailed macaque estimated abundances were 337% and 447% higher than landscapes with <1% oil palm coverage, respectively, suggesting marked demographic benefits accrued by crop raiding on calorie-rich food subsidies. There was extreme community dominance in forest landscapes with >20% oil palm cover where two pig and two macaque species accounted for >80% of independent camera trap detections, leaving <20% for the other 85 mammal species >1 kg considered. Establishing the population trends of pigs and macaques is imperative since they are linked to cascading impacts on the fauna and flora of local forest ecosystems, disease and human health, and economics (i.e., crop losses). The severity of potential negative cascading effects may motivate control efforts to achieve ecosystem integrity, human health and conservation objectives. Our review concludes that the rise of native generalists can be mediated by specific types of degradation, which influences the ecology and conservation of natural areas, creating both positive and detrimental impacts on intact ecosystems and human society.
Collapse
Affiliation(s)
- Jonathan H Moore
- School of Environmental Science and Engineering, Southern University of Science and Technology, 1088 Xueyuan Blvd, Nanshan, Shenzhen, China
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Luke Gibson
- School of Environmental Science and Engineering, Southern University of Science and Technology, 1088 Xueyuan Blvd, Nanshan, Shenzhen, China
| | - Zachary Amir
- School of Biological Sciences, University of Queensland, Brisbane, St Lucia, Queensland, 4072, Australia
| | - Wirong Chanthorn
- Department of Environmental Technology and Management, Faculty of Environment, Kasetsart University, 50 Ngamwongwan Road, Jatujak District, Bangkok, 10900, Thailand
| | - Abdul Hamid Ahmad
- Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Jalan UMS, Kota Kinabalu, 88400, Malaysia
| | - Patrick A Jansen
- Department of Environmental Sciences, Wageningen University, Droevendaalsesteeg 4, Wageningen, 6708 PB, Netherlands
- Smithsonian Tropical Research Institute, Roosevelt Ave. Tupper Building - 401, Panama City, 0843-03092, Panama
| | - Calebe P Mendes
- School of Biological Sciences, University of Queensland, Brisbane, St Lucia, Queensland, 4072, Australia
| | - Manabu Onuma
- National Institute for Environmental Studies, 16-2 Onagava, Tsukuba-City, 305-8506, Japan
| | - Carlos A Peres
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
- Instituto Juruá, R. Ajuricaba, 359 - Aleixo, Manaus, 69083-020, Brazil
| | - Matthew Scott Luskin
- School of Biological Sciences, University of Queensland, Brisbane, St Lucia, Queensland, 4072, Australia
- Centre for Biodiversity and Conservation Science, University of Queensland, St Lucia, Queensland, 4072, Australia
| |
Collapse
|
2
|
Chen Y, McConkey KR, Fan P. Sympatric primate seed dispersers and predators jointly contribute to plant diversity in a subtropical forest. Oecologia 2023; 202:715-727. [PMID: 37553533 DOI: 10.1007/s00442-023-05430-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Accepted: 07/27/2023] [Indexed: 08/10/2023]
Abstract
Mutualistic and antagonistic plant-animal interactions differentially contribute to the maintenance of species diversity in ecological communities. Although both seed dispersal and predation by fruit-eating animals are recognized as important drivers of plant population dynamics, the mechanisms underlying how seed dispersers and predators jointly affect plant diversity remain largely unexplored. Based on mediating roles of seed size and species abundance, we investigated the effects of seed dispersal and predation by two sympatric primates (Nomascus concolor and Trachypithecus crepusculus) on local plant recruitment in a subtropical forest of China. Over a 26 month period, we confirmed that these primates were functionally distinct: gibbons were legitimate seed dispersers who dispersed seeds of 44 plant species, while langurs were primarily seed predators who destroyed seeds of 48 plant species. Gibbons dispersed medium-seeded species more effectively than small- and large-seeded species, and dispersed more seeds of rare species than common and dominant species. Langurs showed a similar predation rate across different sizes of seeds, but destroyed a large number of seeds from common species. Due to gut passage effects, gibbons significantly shortened the duration of seed germination for 58% of the dispersed species; however, for 54% of species, seed germination rates were reduced significantly. Our study underlined the contrasting contributions of two primate species to local plant recruitment processes. By dispersing rare species and destroying the seeds of common species, both primates might jointly maintain plant species diversity. To maintain healthy ecosystems, the conservation of mammals that play critical functional roles needs to receive further attention.
Collapse
Affiliation(s)
- Yuan Chen
- School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, China
- School of Tropical Agriculture and Forestry, Hainan University, Haikou, 570228, China
| | - Kim R McConkey
- School of Environmental and Geographical Sciences, University of Nottingham Malaysia, 43500, Semenyih, Selangor, Malaysia
| | - Pengfei Fan
- School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, China.
| |
Collapse
|
3
|
Williams PJ, Brodie JF. Predicting how defaunation-induced changes in seed predation and dispersal will affect tropical tree populations. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2023; 37:e14014. [PMID: 36178021 DOI: 10.1111/cobi.14014] [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: 02/01/2022] [Accepted: 09/21/2022] [Indexed: 06/16/2023]
Abstract
The loss of large animals due to overhunting and habitat loss potentially affects tropical tree populations and carbon cycling. Trees reliant on large-bodied seed dispersers are thought to be particularly negatively affected by defaunation. But besides seed dispersal, defaunation can also increase or decrease seed predation. It remains unclear how these different defaunation effects on early life stages ultimately affect tree population dynamics. We reviewed the literature on how tropical animal loss affects different plant life stages, and we conducted a meta-analysis of how defaunation affects seed predation. We used this information to parameterize models that altered matrix projection models from a suite of tree species to simulate defaunation-caused changes in seed dispersal and predation. We assessed how applying these defaunation effects affected population growth rates. On average, population-level effects of defaunation were negligible, suggesting that defaunation may not cause the massive reductions in forest carbon storage that have been predicted. In contrast to previous hypotheses, we did not detect an effect of seed size on changes in seed predation rates. The change in seed predation did not differ significantly between exclosure experiments and observational studies, although the results of observational studies were far more variable. Although defaunation surely affects certain tree taxa, species that benefit or are harmed by it and net changes in forest carbon storage cannot currently be predicted based on available data. Further research on how factors such as seed predation vary across tree species and defaunation scenarios is necessary for understanding cascading changes in species composition and diversity.
Collapse
Affiliation(s)
| | - Jedediah F Brodie
- Division of Biological Sciences, University of Montana, Missoula, Montana, USA
- Wildlife Biology Program, University of Montana, Missoula, Montana, USA
- Institute of Biodiversity and Environmental Conservation, Universiti Malaysia Sarawak, Kota Samarahan, Sarawak, Malaysia
| |
Collapse
|
4
|
Lamperty T, Chiok WX, Khoo MDY, Amir Z, Baker N, Chua MAH, Chung YF, Chua YK, Koh JJ, Lee BPY, Lum SKY, Mendes CP, Ngiam J, ODempsey A, Png KGC, Sophie AR, Tan L, Teo R, Thomas N, Tianjiao L, Tze‐Ming BL, Loo AHB, Wardle DA, Luskin MS. Rewilding in Southeast Asia: Singapore as a case study. CONSERVATION SCIENCE AND PRACTICE 2023. [DOI: 10.1111/csp2.12899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Affiliation(s)
- Therese Lamperty
- Asian School of the Environment Nanyang Technological University Singapore
- Department of Biology University of Washington Seattle Washington, DC USA
| | - Wen Xuan Chiok
- Asian School of the Environment Nanyang Technological University Singapore
| | - Max D. Y. Khoo
- National Parks Board Singapore Botanic Gardens Singapore
| | - Zachary Amir
- Centre for Biodiversity and Conservation Science University of Queensland Brisbane Australia
| | | | - Marcus A. H. Chua
- Department of Biological Science National University of Singapore Singapore
- Lee Kong Chian Natural History Museum National University of Singapore Singapore
| | - Yi Fei Chung
- National Parks Board Singapore Botanic Gardens Singapore
- School of Applied Science, Republic Polytechnic Singapore
| | - Yen Kheng Chua
- National Parks Board Singapore Botanic Gardens Singapore
| | - Joshua J.‐M. Koh
- Department of Biological Science National University of Singapore Singapore
| | | | - Shawn K. Y. Lum
- Asian School of the Environment Nanyang Technological University Singapore
| | - Calebe P. Mendes
- Centre for Biodiversity and Conservation Science University of Queensland Brisbane Australia
- Natural Sciences & Science Education National Institute of Education Singapore
| | - Jonathan Ngiam
- National Parks Board Singapore Botanic Gardens Singapore
| | | | - Kenny G. C. Png
- Asian School of the Environment Nanyang Technological University Singapore
| | - Adia R. Sophie
- Centre for Biodiversity and Conservation Science University of Queensland Brisbane Australia
| | - Lorraine Tan
- National Parks Board Singapore Botanic Gardens Singapore
| | - Robert Teo
- National Parks Board Singapore Botanic Gardens Singapore
| | - Noel Thomas
- National Parks Board Singapore Botanic Gardens Singapore
| | - Li Tianjiao
- National Parks Board Singapore Botanic Gardens Singapore
| | | | | | - David A. Wardle
- Asian School of the Environment Nanyang Technological University Singapore
| | - Matthew Scott Luskin
- Asian School of the Environment Nanyang Technological University Singapore
- Centre for Biodiversity and Conservation Science University of Queensland Brisbane Australia
- Forest Global Earth Observatory—Center for Tropical Forest Science Smithsonian Tropical Research Institute Seattle Washington, DC USA
- School of Biological Sciences University of Queensland Brisbane Australia
| |
Collapse
|
5
|
Amir Z, Moore JH, Negret PJ, Luskin MS. Megafauna extinctions produce idiosyncratic Anthropocene assemblages. SCIENCE ADVANCES 2022; 8:eabq2307. [PMID: 36269822 PMCID: PMC9586473 DOI: 10.1126/sciadv.abq2307] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 09/02/2022] [Indexed: 06/15/2023]
Abstract
The "trophic downgrading of planet Earth" refers to the systematic decline of the world's largest vertebrates. However, our understanding of why megafauna extinction risk varies through time and the importance of site- or species-specific factors remain unclear. Here, we unravel the unexpected variability in remaining terrestrial megafauna assemblages across 10 Southeast Asian tropical forests. Consistent with global trends, every landscape experienced Holocene and/or Anthropocene megafauna extirpations, and the four most disturbed landscapes experienced 2.5 times more extirpations than the six least disturbed landscapes. However, there were no consistent size- or guild-related trends, no two tropical forests had identical assemblages, and the abundance of four species showed positive relationships with forest degradation and humans. Our results suggest that the region's megafauna assemblages are the product of a convoluted geoclimatic legacy interacting with modern disturbances and that some megafauna may persist in degraded tropical forests near settlements with sufficient poaching controls.
Collapse
Affiliation(s)
- Zachary Amir
- School of Biological Sciences, The University of Queensland, St. Lucia, QLD, Australia
| | - Jonathan H. Moore
- School of Environmental Sciences, University of East Anglia, Norwich, UK
| | - Pablo Jose Negret
- School of Earth and Environmental Sciences, The University of Queensland, St. Lucia, QLD, Australia
| | - Matthew Scott Luskin
- School of Biological Sciences, The University of Queensland, St. Lucia, QLD, Australia
- Centre for Biodiversity and Conservation Science, The University of Queensland, St. Lucia, QLD, Australia
| |
Collapse
|
6
|
Song X, Corlett RT. Do natural enemies mediate conspecific negative distance‐ and density‐dependence of trees? A meta‐analysis of exclusion experiments. OIKOS 2021. [DOI: 10.1111/oik.08509] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xiaoyang Song
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences Mengla China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences Mengla China
| | - Richard T. Corlett
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences Mengla China
- Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences Mengla China
| |
Collapse
|