Keystone species and food webs

Abstract

Different species are of different importance in maintaining ecosystem functions in natural communities. Quantitative approaches are needed to identify unusually important or influential, 'keystone' species particularly for conservation purposes. Since the importance of some species may largely be the consequence of their rich interaction structure, one possible quantitative approach to identify the most influential species is to study their position in the network of interspecific interactions. In this paper, I discuss the role of network analysis (and centrality indices in particular) in this process and present a new and simple approach to characterizing the interaction structures of each species in a complex network. Understanding the linkage between structure and dynamics is a condition to test the results of topological studies, I briefly overview our current knowledge on this issue. The study of key nodes in networks has become an increasingly general interest in several disciplines: I will discuss some parallels. Finally, I will argue that conservation biology needs to devote more attention to identify and conserve keystone species and relatively less attention to rarity.

Twenty-first century approaches to ancient problems: Climate and society

“…Although a traditional zooarchaeological study would certainly note the presence or absence of species (91), food-web approaches additionally allow us to examine the effects of species additions and removals on the ecosystem as a whole (92). These approaches also allow for detection of keystone species via centrality measures (93). Finally, by displaying the patterns in large datasets, they provide a source for inferences about the processes creating the food web and allow for synthesis of large amounts of information (90).…”

Resistance Distance, Information Centrality, Node Vulnerability and Vibrations in Complex Networks

“…Then, it is not rare that concepts arising in one discipline are rediscovered and used in another with success. For instance, the concept of node centrality [18,32], which arises in the study of social networks, is now widely used in the analysis of biological, ecological, and infrastructural networks [5,7,9,11,13,21,22]. Another example is given by the Wiener index, which was introduced in 1947 [34] and defined as the sum of the distances of all shortest paths in the graph representing hydrocarbon molecules.…”

Analyzing Ecological Systems Using Network Analysis

“…Other approaches to ecological network analysis have been published elsewhere such as investigation of food webs (Dunne et al 2002(Dunne et al , 2004Christian & Luczkovich 1999), pollination networks (Bascompte et al 2003;Olesen et al 2007), and keystone species (Jordan 2009;Jordan et al 2009;Ortiz et al 2013) to mention a few. Here, I provide an overview of flow-based network methodology called Environ Analysis (Patten 1978) with sample applications.…”