Relative contribution of ecological and biological attributes in the fine-grain structure of ant-plant networks

PeerJ

article

Cecilia Díaz-Castelazo¹  Cristian A. Martínez-Adriano¹  Wesley Dáttilo³  Victor Rico-Gray⁴ 

[1] Red de Interacciones Multitróficas, Instituto de Ecología;Facultad de Ciencias Forestales, Universidad Autónoma de Nuevo León;Red de Ecoetología, Instituto de Ecología;Instituto de Neuroetología, Universidad Veracruzana

关键词: Ant behavior;    Ant-plant mutualism;    Biological attributes;    Community ecology;    Determinants of network structure;    Ecological networks;    Extrafloral nectaries;    Habitat structure;    Invasive species;   

DOI  :  10.7717/peerj.8314

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

BackgroundEcological communities of interacting species analyzed as complex networks have shown that species dependence on their counterparts is more complex than expected at random. As for other potentially mutualistic interactions, ant-plant networks mediated by extrafloral nectar show a nested (asymmetric) structure with a core of generalist species dominating the interaction pattern. Proposed factors structuring ecological networks include encounter probability (e.g., species abundances and habitat heterogeneity), behavior, phylogeny, and body size. While the importance of underlying factors that influence the structure of ant-plant networks have been separately explored, the simultaneous contribution of several biological and ecological attributes inherent to the species, guild or habitat level has not been addressed.MethodsFor a tropical seasonal site we recorded (in 48 censuses) the frequency of pairwise ant-plant interactions mediated by extrafloral nectaries (EFN) on different habitats and studied the resultant network structure. We addressed for the first time the role of mechanistic versus neutral determinants at the ‘fine-grain’ structure (pairwise interactions) of ant-plant networks. We explore the simultaneous contribution of several attributes of plant and ant species (i.e., EFN abundance and distribution, ant head length, behavioral dominance and invasive status), and habitat attributes (i.e., vegetation structure) in prevailing interactions as well as in overall network topology (community).ResultsOur studied network was highly-nested and non-modular, with core species having high species strengths (higher strength values for ants than plants) and low specialization. Plants had higher dependences on ants than vice versa. We found that habitat heterogeneity in vegetation structure (open vs. shaded habitats) was the main factor explaining network and fine-grain structure, with no evidence of neutral (abundance) effects.DiscussionCore ant species are relevant to most plants species at the network showing adaptations to nectar consumption and deterrent behavior. Thus larger ants interact with more plant species which, together with higher dependence of plants on ants, suggests potential biotic defense at a community scale. In our study site, heterogeneity in the ant-plant interactions among habitats is so prevalent that it emerges at community-level structural properties. High frequency of morphologically diverse and temporarily-active EFNs in all habitats suggests the relevance and seasonality of plant biotic defense provided by ants. The robust survey of ecological interactions and their biological/ecological correlates that we addressed provides insight of the interplay between adaptive-value traits and neutral effects in ecological networks.

【 授权许可】

CC BY