Beyond species loss: the extinction of ecological interactions in a changing world

Abstract

Summary1. The effects of the present biodiversity crisis have been largely focused on the loss of species. However, a missed component of biodiversity loss that often accompanies or even precedes species disappearance is the extinction of ecological interactions. 2. Here, we propose a novel model that (i) relates the diversity of both species and interactions along a gradient of environmental deterioration and (ii) explores how the rate of loss of ecological functions, and consequently of ecosystem services, can be accelerated or restrained depending on how the rate of species loss covaries with the rate of interactions loss. 3. We find that the loss of species and interactions are decoupled, such that ecological interactions are often lost at a higher rate. This implies that the loss of ecological interactions may occur well before species disappearance, affecting species functionality and ecosystems services at a faster rate than species extinctions. We provide a number of empirical case studies illustrating these points. 4. Our approach emphasizes the importance of focusing on species interactions as the major biodiversity component from which the 'health' of ecosystems depends.

The value of trophic interactions for ecosystem function: dung beetle communities influence seed burial and seedling recruitment in tropical forests

“…So too is the ongoing decline in the abundances of individuals that remain. It is increasingly recognized that this erosion of biodiversity will lead to the breakdown of species interactions and a loss of associated ecosystem functions and services [3,4].…”

Neutral theory of biodiversity: Controversies and a transvaluation of species conservation

“…Se a teoria neutra de Hubbell se aplica por completo ou não na natureza, é uma dúvida que persiste (Poulin, 2004;McGill et al, 2006;Connolly et al, 2017), porém a possibilidade de aplicação desta teoria demonstra que as justificativas de estudos ecológicos precisam mudar da simples necessidade de "conservar" para uma motivação mais voltada para a aquisição de conhecimento e a busca pela compreensão do funcionamento da natureza e autopreservação. Essa necessidade também é reforçada pelo fato de muitas interações tróficas serem redundantes e não necessariamente funcionais, característica que dá certa robustez às comunidades biológicas diante de certas alterações ambientais ou enfraquecê-las diante daquelas cumulativas ou constantes (Allesina et al, 2009;Valiente--Banuet et al, 2015) remetendo, de certa forma, à equivalência trófica de Hubbell.…”

“…Tal pretensão pode não advir apenas da necessidade de conhecimento científico, mas também de compreender quais fatores estão envolvidos em um possível colapso da biodiversidade nos próximos anos (Hubbell, 2001;Valiente-Banuet et al, 2015).…”

Heterotilapia buttikoferi (Hubrecht, 1881) (Perciformes: Cichlidae), an introduced exotic fish in the upper Paraná river basin

“…The loss of biodiversity throughout freshwater ecosystems is linked to various factors including siltation, eutrophication, pollution, presence of hydroeletric plants and dams, flood control, over-exploitation of resources, and exotic species (Reis 2013, Britton and Gozlan 2013, Orsi and Britton 2014, Valiente-Banuet et al 2015. Among these threats, the impacts of invasive species are particularly alarming, especially in degraded environments, such as near hydroelectric plants, that benefit the establishment of populations of invasive species , Pelicice et al 2014, Kalous et al 2015, Thomaz et al 2015, Daga et al 2015, Pagad et al 2015.…”