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Zhu N, Li X, Wu X, Li L, Yang S, Fu H, Yuan S. Effects of overgrazing on the functional diversity of rodents in desert areas. Ecol Evol 2024; 14:e10849. [PMID: 38384828 PMCID: PMC10879905 DOI: 10.1002/ece3.10849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 11/06/2023] [Accepted: 01/02/2024] [Indexed: 02/23/2024] Open
Abstract
Environmental stressors and disturbances can cause changes in an ecosystem's community structure, which can be reflected in its functional diversity. As grazing intensity increases, this causes changes in the environment that inevitably lead to changes in the community structure, which can especially affect rodents due to their sensitivity to the environment. The effects of grazing prohibition and overgrazing on the functional diversity of desert rodent communities in Alxa were studied in April, July, and October of 2018-2020. The trap-day method was used to study rodent communities in disturbed habitats. Five functional traits were selected and quantified: nutrition, life history, physiology, morphology, and activity rhythm. The results showed that: (1) The species composition of rodent communities in the Alxa Desert in spring and autumn was significantly correlated with the functional traits of the hibernation, reproductive cycle, and feeding habits. The species composition in the summer was only significantly correlated with the functional traits of reproductive cycle and diet. (2) The effects of overgrazing on the functional diversity of rodents in desert areas have significant temporal and spatial characteristics. (3) In spring and summer, overgrazing made the Functional Richness index of the rodent community lower than that of areas where grazing is prohibited, but the Functional Evenness index was higher than that of grazing-prohibition areas. In autumn, overgrazing increased the Functional Richness index of the rodent community and decreased the Functional Evenness index. The Functional Divergence index was higher in overgrazing areas than in grazing-prohibited ones. These results suggest that, in spring and summer, overgrazing reduced the ecological space utilization ability of rodent communities; however, the impact on the degree of utilization of community resources is more comprehensive. In autumn, overgrazing increases the ability of rodent communities to use ecological space but reduces resource efficiency. Overgrazing makes the niche differentiation of rodent communities higher, the degree of overlap lower, and the competition between species weaker. Therefore, overgrazing will affect the functional diversity of the community through the utilization of ecological space, resource utilization, interspecific competition, and niche.
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Affiliation(s)
- Na Zhu
- Key Laboratory of Grassland Rodent Ecology and Pest Controlled, Inner MongoliaHohhotChina
- Key Laboratory of Grassland Resources of the Ministry of EducationHohhotChina
- College of Grassland, Resources and EnvironmentInner Mongolia Agricultural UniversityHohhotChina
| | - Xin Li
- Key Laboratory of Grassland Rodent Ecology and Pest Controlled, Inner MongoliaHohhotChina
- Key Laboratory of Grassland Resources of the Ministry of EducationHohhotChina
- College of Grassland, Resources and EnvironmentInner Mongolia Agricultural UniversityHohhotChina
| | - Xiaodong Wu
- Key Laboratory of Grassland Rodent Ecology and Pest Controlled, Inner MongoliaHohhotChina
- Key Laboratory of Grassland Resources of the Ministry of EducationHohhotChina
- College of Grassland, Resources and EnvironmentInner Mongolia Agricultural UniversityHohhotChina
| | - Linlin Li
- Key Laboratory of Grassland Rodent Ecology and Pest Controlled, Inner MongoliaHohhotChina
- Key Laboratory of Grassland Resources of the Ministry of EducationHohhotChina
- College of Grassland, Resources and EnvironmentInner Mongolia Agricultural UniversityHohhotChina
| | - Suwen Yang
- College of Grassland ScienceXinjiang Agricultural UniversityUrumqiChina
| | - Heping Fu
- Key Laboratory of Grassland Rodent Ecology and Pest Controlled, Inner MongoliaHohhotChina
- Key Laboratory of Grassland Resources of the Ministry of EducationHohhotChina
- College of Grassland, Resources and EnvironmentInner Mongolia Agricultural UniversityHohhotChina
| | - Shuai Yuan
- Key Laboratory of Grassland Rodent Ecology and Pest Controlled, Inner MongoliaHohhotChina
- Key Laboratory of Grassland Resources of the Ministry of EducationHohhotChina
- College of Grassland, Resources and EnvironmentInner Mongolia Agricultural UniversityHohhotChina
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Marcacci G, Westphal C, Rao VS, Kumar S S, Tharini KB, Belavadi VV, Nölke N, Tscharntke T, Grass I. Urbanization alters the spatiotemporal dynamics of plant-pollinator networks in a tropical megacity. Ecol Lett 2023; 26:1951-1962. [PMID: 37858984 DOI: 10.1111/ele.14324] [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: 02/13/2023] [Accepted: 09/01/2023] [Indexed: 10/21/2023]
Abstract
Urbanization is a major driver of biodiversity change but how it interacts with spatial and temporal gradients to influence the dynamics of plant-pollinator networks is poorly understood, especially in tropical urbanization hotspots. Here, we analysed the drivers of environmental, spatial and temporal turnover of plant-pollinator interactions (interaction β-diversity) along an urbanization gradient in Bengaluru, a South Indian megacity. The compositional turnover of plant-pollinator interactions differed more between seasons and with local urbanization intensity than with spatial distance, suggesting that seasonality and environmental filtering were more important than dispersal limitation for explaining plant-pollinator interaction β-diversity. Furthermore, urbanization amplified the seasonal dynamics of plant-pollinator interactions, with stronger temporal turnover in urban compared to rural sites, driven by greater turnover of native non-crop plant species (not managed by people). Our study demonstrates that environmental, spatial and temporal gradients interact to shape the dynamics of plant-pollinator networks and urbanization can strongly amplify these dynamics.
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Affiliation(s)
- Gabriel Marcacci
- Functional Agrobiodiversity, University of Göttingen, Göttingen, Germany
- Swiss Ornithological Institute, Sempach, Switzerland
| | - Catrin Westphal
- Functional Agrobiodiversity, University of Göttingen, Göttingen, Germany
- Centre of Biodiversity and Sustainable Land Use (CBL), University of Göttingen, Göttingen, Germany
| | - Vikas S Rao
- Agricultural Entomology, University of Agricultural Sciences, GKVK, Bangalore, India
| | - Shabarish Kumar S
- Department of Apiculture, University of Agricultural Sciences, GKVK, Bangalore, India
| | - K B Tharini
- Agricultural Entomology, University of Agricultural Sciences, GKVK, Bangalore, India
| | - Vasuki V Belavadi
- Agricultural Entomology, University of Agricultural Sciences, GKVK, Bangalore, India
| | - Nils Nölke
- Forest Inventory and Remote Sensing, Faculty of Forest Sciences and Forest Ecology, University of Göttingen, Göttingen, Germany
| | - Teja Tscharntke
- Centre of Biodiversity and Sustainable Land Use (CBL), University of Göttingen, Göttingen, Germany
- Agroecology, University of Göttingen, Göttingen, Germany
| | - Ingo Grass
- Ecology of Tropical Agricultural Systems, University of Hohenheim, Stuttgart, Germany
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Marcacci G, Grass I, Rao VS, Kumar S S, Tharini KB, Belavadi VV, Nölke N, Tscharntke T, Westphal C. Functional diversity of farmland bees across rural-urban landscapes in a tropical megacity. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2022; 32:e2699. [PMID: 35751512 DOI: 10.1002/eap.2699] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 04/18/2022] [Accepted: 05/13/2022] [Indexed: 06/15/2023]
Abstract
Urbanization poses a major threat to biodiversity and food security, as expanding cities, especially in the Global South, increasingly compete with natural and agricultural lands. However, the impact of urban expansion on agricultural biodiversity in tropical regions is overlooked. Here we assess how urbanization affects the functional response of farmland bees, the most important pollinators for crop production. We sampled bees across three seasons in 36 conventional vegetable-producing farms spread along an urbanization gradient in Bengaluru, an Indian megacity. We investigated how landscape and local environmental drivers affected different functional traits (sociality, nesting behavior, body size, and specialization) and functional diversity (functional dispersion) of bee communities. We found that the functional responses to urbanization were trait specific with more positive than negative effects of gray area (sealed surfaces and buildings) on species richness, functional diversity, and abundance of most functional groups. As expected, larger, solitary, cavity-nesting, and, surprisingly, specialist bees benefited from urbanization. In contrast to temperate cities, the abundance of ground nesters increased in urban areas, presumably because larger patches of bare soil were still available beside roads and buildings. However, overall bee abundance and the abundance of social bees (85% of all bees) decreased with urbanization, threatening crop pollination. Crop diversity promotes taxonomic and functional diversity of bee communities. Locally, flower resources promote the abundance of all functional groups, and natural vegetation can maintain diverse pollinator communities throughout the year, especially during the noncropping season. However, exotic plants decrease functional diversity and bee specialization. To safeguard bees and their pollination services in urban farms, we recommend (1) preserving seminatural vegetation (hedges) around cropping fields to provide nesting opportunities for aboveground nesters, (2) promoting farm-level crop diversification of beneficial crops (e.g., pulses, vegetables, and spices), (3) maintaining native natural vegetation along field margins, and (4) controlling and removing invasive exotic plants that disrupt native plant-pollinator interactions. Overall, our results suggest that urban agriculture can maintain functionally diverse bee communities and, if managed in a sustainable manner, be used to develop win-win solutions for biodiversity conservation of pollinators and food security in and around cities.
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Affiliation(s)
- Gabriel Marcacci
- Functional Agrobiodiversity, Department of Crop Sciences, University of Göttingen, Göttingen, Germany
| | - Ingo Grass
- Ecology of Tropical Agricultural Systems, University of Hohenheim, Stuttgart, Germany
| | - Vikas S Rao
- Agricultural Entomology, University of Agricultural Sciences, Bangalore, India
| | - Shabarish Kumar S
- Department of Apiculture, University of Agricultural Sciences, Bangalore, India
| | - K B Tharini
- Agricultural Entomology, University of Agricultural Sciences, Bangalore, India
| | - Vasuki V Belavadi
- Agricultural Entomology, University of Agricultural Sciences, Bangalore, India
| | - Nils Nölke
- Forest Inventory and Remote Sensing, Faculty of Forest Sciences and Forest Ecology, University of Göttingen, Göttingen, Germany
| | - Teja Tscharntke
- Agroecology, Department of Crop Sciences, University of Göttingen, Göttingen, Germany
- Centre of Biodiversity and Sustainable Land Use (CBL), University of Göttingen, Göttingen, Germany
| | - Catrin Westphal
- Functional Agrobiodiversity, Department of Crop Sciences, University of Göttingen, Göttingen, Germany
- Centre of Biodiversity and Sustainable Land Use (CBL), University of Göttingen, Göttingen, Germany
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