The Importance of Small-Scale Habitat Structure for Maintaining Beta Diversity

Abstract

Marine soft sediments are often considered to be vast, homogeneous expanses of mud or sand; however, most exhibit small‐scale biogenic structures. Generally such structures result from short‐term processes, but mollusk shell debris can last for centuries, providing a settlement surface for plants and animals, which in turn stabilize the debris. This study sampled patches of shell debris and the surrounding sediment at increasing distances from the patches to determine the role of the patches in driving beta biodiversity. Sampling was conducted at three similar sites within 1 km in a marine reserve in New Zealand. The shell debris significantly affected beta diversity at all sites, although the magnitude of the effect was dependent on patch size, density, and debris particle size. These results have important implications for estimating and mapping biodiversity. They also have implications for marine conservation. The role of shell debris, suggested by this study, in increasing and maintaining biodiversity, emphasizes a need for reducing disturbance regimes and actively managing seafloor habitats in areas not previously considered for such.

How Should Beta-Diversity Inform Biodiversity Conservation?

“…Exploitation also has indirect effects on beta-diversity. For example, bottomtrawling homogenizes benthic communities by destroying microhabitats on the sea 250 floor [75]. In tropical forests, hunting removes seed dispersers, causing hyperdiverse tree assemblages to give way to depauperate communities of species capable of recruiting near conspecific adults [76].…”

“…But at its worst, it can be a mathematical abstraction that is easy to misapply and misinterpret. In this review, we highlight recent advances and potential pitfalls in the application of beta-diversity to 75 conservation science.…”

Seafloor change detection using multibeam echosounder backscatter: case study on the Belgian part of the North Sea

“…If indeed smothering and/or deposition events would be more persistent under increased anthropogenic pressure, this may affect several ecosystem states and functions: e.g. reduction of sessile bio-encrusting epifauna; loss of surficial complexity leading to reduced micro-roughness; burial of biogenic clastic material; and overall reduced potential of bentho-pelagic coupling (Watling and Norse 1998;Hewitt et al 2005).…”

Influence of environmental factors on the dynamics of macrobenthic crustaceans on soft-bottoms of the Ebro Delta continental shelf (northwestern Mediterranean)

“…Though many studies on soft-bottom macrofauna carried out over decades have addressed a wide range of aspects, most of them focus on diversity patterns (e.g. Gray, 2000;Ellingsen and Gray, 2002;Hewitt et al, 2005) and the species distribution over spatial and environmental gradients (e.g. Clarke and Ainsworth, 1993;Ellingsen, 2002;Gobin and Warwick, 2006).…”