An ecological survey of the invertebrate community at the epigean/hypogean interface

By

Mammola, Stefano
Piano, Elena
Giachino, Pier Mauro
Isaia, Marco

Type

Article

Date of Publication

2017

Original Publication

Subterranean Biology

Volume

24

Pages

27-52

Subjects

Cave fauna , Ecological gradient , Mesovoid Shallow Substratum , Subterranean Biology , Subterranean Sampling Device , Superficial Subterranean Habitats , troglobionts

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/subtbiol.24.21585

 

Abstract

We studied the ecological continuum between caves and the associated network of fissures – Milieu Souterrain Superficiel (MSS) – in an hypogean site in the Graian Alps, Italy. Over one year, we surveyed the faunal assemblages by means of pitfall traps placed in the caves and specific subterranean sampling devices (SSD) buried in the MSS. We used generalized linear mixed models (GLMMs) and generalized additive mixed models (GAMMs) to compare the spatial and temporal dynamics of the subterranean invertebrates inhabiting the two environments. As expected, arthropod communities occurring near the surface were characterized by minor level of subterranean adaptations, and conversely, subterranean species were more abundant and diversified at higher depths, both in the caves and in the MSS. Diversity and abundance of external elements in the superficial layers were found to be highly seasonal dependent, with minor values in winter compared to the other seasons. We provided information about the faunal assemblages dwelling in the two hypogean compartments, and we characterized the microclimatic conditions therein. We discussed the existence of an ecological gradient of specialization extending from the surface to the deep hypogean layers, which can be interpreted in light of the microclimatic changes occurring at increasing depths and the parallel decrease in available organic matter.