Agricultural input modifies trophic niche and basal energy source of a top predator across human-modified landscapes
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View abstract on PubMed
Summary
This summary is machine-generated.Habitat fragmentation impacts food webs. In Brazil, caiman (Caiman crocodilus) adapted to agricultural areas by utilizing diverse food sources, indicating landscape management can support biodiversity.
Area Of Science
- Ecology and Conservation Biology
- Food Web Dynamics
- Landscape Ecology
Background
- Land-use conversion and habitat fragmentation disrupt ecosystem functions, altering food web structures and leading to biodiversity loss.
- The Araguaia River floodplain in central Brazil is a dynamic landscape experiencing significant modification.
- The Spectacled Caiman (Caiman crocodilus) serves as an indicator species for assessing ecosystem health due to its apex predator role.
Purpose Of The Study
- To investigate the effects of landscape modification on the food web structure and primary productivity sources utilized by Caiman crocodilus.
- To evaluate spatial and temporal variations in caiman isotopic niche width in response to habitat attributes.
- To determine if natural and anthropogenic areas support food webs with different primary producers.
Main Methods
- Carbon (δ13C) and nitrogen (δ15N) isotope values were measured in three caiman tissues with varying turnover rates.
- Hierarchical Bayesian models were employed to analyze isotopic niche width, incorporating habitat use, sex, body size, and landscape composition/configuration.
- Essential amino acid δ13C values were analyzed to trace the sources of primary productivity fueling aquatic food webs in natural versus anthropogenic zones.
Main Results
- Caimans inhabiting agricultural areas exhibited significantly larger isotopic niche widths compared to those in natural habitats.
- This expanded niche likely reflects the incorporation of terrestrial resources, particularly C4 plants, into the diets of caimans in modified landscapes.
- Distinct patterns in essential amino acid δ13C values between natural and anthropogenic habitats confirmed differences in primary energy sources.
Conclusions
- Caiman crocodilus demonstrates adaptability, capable of persisting in heterogeneous landscapes by utilizing both natural and agricultural energy sources.
- These findings highlight the potential for effective landscape management strategies that integrate natural and anthropogenic areas to support biodiversity.
- The study underscores the importance of understanding food web responses to land-use change for conservation efforts in tropical floodplains.
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