Does the Cave Environment Reduce Functional Diversity?

Author(s)

Fernandes, Camile Sorbo ^[1] ; Batalha, Marco Antonio ^[2] ; Bichuette, Maria Elina ^[1]

Affiliation

^[1] Univ Fed Sao Carlos, Dept Ecol & Evolutionary Biol, POB 676, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Fed Sao Carlos, Dept Bot, POB 676, BR-13565905 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: PLoS One; v. 11, n. 3 MAR 22 2016.
• Web of Science Citations: 15

Abstract

Caves are not colonised by all taxa present in the surface species pool, due to absence of light and the tendency to food limitation when compared to surface communities. Under strong species sorting during colonisation and later by the restrictive environmental filter, traits that are not adaptive in subterranean habitats may be filtered out. We tested whether cave communities were assembled by the restrictive regime propitiated by permanent darkness or by competitive exclusion due to resource scarcity. When compared to surface communities, the restrictive subterranean regime would lead to lower functional diversity and phenotypic clustering inside the caves, and the opposite should be expected in the case of competitive exclusion. Using isopods (Oniscidea) as model taxa, we measured several niche descriptors of taxa from surface and cave habitats, used a multivariate measure of functional diversity, and compared their widths. We found phenotypic overdispersion and higher functional diversity in cave taxa when compared to surface taxa. On the one hand, the dry climate outside of caves hampered the survival of several taxa and their ecological strategies, not viable under severe desiccation risk, culminating in the clustering of functional traits. In contrast, this restriction does not occur inside of caves, where isopods find favourable conditions under lower predation pressures and more amenable environmental parameters that allow occupation and subsequent diversification. Our results showed that, at least for some taxa, caves may not be such a harsh environment as previously thought. The high functional diversity we found inside caves adds an additional reason for the conservation of these sensitive environments. (AU)

• FAPESP's process: 08/05678-7 - Population ecology and behaviour of Brazilian subterranean fishes, genera Glaphyropoma and Copionodon Pinna, 1992 (Siluriformes: Trichomycteridae: Copionodontinae) from Chapada Diamantina, central Bahia
• Grantee: Maria Elina Bichuette
• Support Opportunities: Regular Research Grants
• FAPESP's process: 10/08459-4 - Are the São Desidério, Serra do Ramalho (southwest Bahia) and São Domingos (northeast Goiás) biodiversity hot spots karstic areas? Cave community analysis and protection criteria
• Grantee: Maria Elina Bichuette
• Support Opportunities: Regular Research Grants
• FAPESP's process: 08/57949-4 - Institute to Studies of the Parasitic Hymenoptera at the Brazilian Southeastern Region – HYMPAR
• Grantee: Angélica Maria Penteado Martins Dias
• Support Opportunities: Research Projects - Thematic Grants