Habitat structure mediates biodiversity effects on ecosystem properties

Abstract

Much of what we know about the role of biodiversity in mediating ecosystem processes and function stems from manipulative experiments, which have largely been performed in isolated, homogeneous environments that do not incorporate habitat structure or allow natural community dynamics to develop. Here, we use a range of habitat configurations in a model marine benthic system to investigate the effects of species composition, resource heterogeneity and patch connectivity on ecosystem properties at both the patch (bioturbation intensity) and multi-patch (nutrient concentration) scale. We show that allowing fauna to move and preferentially select patches alters local species composition and density distributions, which has negative effects on ecosystem processes (bioturbation intensity) at the patch scale, but overall positive effects on ecosystem functioning (nutrient concentration) at the multi-patch scale. Our findings provide important evidence that community dynamics alter in response to localized resource heterogeneity and that these small-scale variations in habitat structure influence species contributions to ecosystem properties at larger scales. We conclude that habitat complexity forms an important buffer against disturbance and that contemporary estimates of the level of biodiversity required for maintaining future multi-functional systems may need to be revised.

Functional effects of the hadal sea cucumber Elpidia atakama (Echinodermata: Holothuroidea, Elasipodida) reflect small-scale patterns of resource availability

“…However, our findings provide compelling evidence that E. atakama is a functionally important species that is likely to change its behaviour in response to localised resource heterogeneity (Godbold et al 2009(Godbold et al , 2011 and the repackaging of organic matter (OM; Bett et al 2001). Also, movement over the sediment surface associated with relocation constitutes Fig.…”

“…In the present study, E. atakama spent 150 min relocating and 267 min feeding (a ratio of 1:1.8), suggesting that resource supply is indeed abundant and that the distance between patches is relatively short (20-40 min travel time, or approximately 10 body length distance). This pattern of movement suggests considerable sensitivity to food concentration (McClintic et al 2008) and implies that the dynamics and organisation of hadal communities are intimately linked to habitat structure and the distribution of resources in ways similar to those found in shallower benthic communities (Levinton and Kelaher 2004;Dyson et al 2007;Bulling et al 2008;Nogaro et al 2008;Godbold et al 2011). Thus, the cumulative response of hadal species to such small-scale variation is likely to influence species contributions to ecosystem properties at much larger scales (Godbold et al 2011).…”

Riparian Deforestation Affects the Structural Dynamics of Headwater Streams in Southern Brazilian Amazonia

“…Godbold et al [54] emphasize the importance of diversified/complex habitats in maintaining ecosystem multifunctionality, where different species affect different functions [55,56] and can therefore minimize the effects of perturbations.…”

Form, function and physics: the ecology of biogenic stabilisation

“…Natural environments tend to be heterogeneous, whereas mesocosm or laboratory studies are generally controlled homogeneous environments (Dyson et al 2007). Natural heterogeneity has been observed to buffer against stressor effects (Godbold et al 2011) or negate patterns observed under laboratory conditions (Bulling et al 2008).…”