Network properties and keystoneness assessment in different intertidal communities dominated by two ecosystem engineer species (SE Pacific coast): A comparative analysis

Marco Ortiz, Leonardo Campos, Fernando Berrios, Fabián Rodriguez, Brenda Hermosillo and Jorge González

Ecological Modelling, 2013, vol. 250, issue C, 307-318

Abstract: Multispecies quantitative and qualitative models of the kelp Lessonia nigrescens and the tunicate Pyura praeputialis were constructed for intertidal areas of northern Chile (SE Pacific). Information on biomass, P/B ratios, catches, food spectrum, consumption and dynamics of commercial and non-commercial species was obtained and examined using Ecopath with Ecosim and Loop Analysis theoretical frameworks. The biomass of L. nigrescens and P. praeputialis constituted the most important compartments, exceeding 97% of the total biomass in each model system. Based on Pp/R, the system of P. praeputialis appeared to be the most developed. However, according to Pp/B, A/C, Ai/Ci, and redundancy, the L. nigrescens system was the most developed and, in turn, the least resistant to disturbances. The results obtained using mixed trophic impacts (MTI), Ecosim simulations, and system recovery time (SRT) showed different response patterns. The tunicate species propagated higher effects on the remaining species, whereas the kelp species presented the longest SRT (as a resilience measure). The model keystone species indices suggested that each model system contained a core of ecologically related species. In the L. nigrescens system, core was made up of the filter feeders Semimytilus algosus, barnacles, and small epifauna herbivores (SEH) and the predators Concholepas concholepas and Heliaster helianthus. In the P. praeputialis system, the core consisted of phyoplankton, zooplankton, other filter feeders and the predators C. concholepas, H. helianthus, other starfish, and large epifauna. The outcomes obtained in the current work did not indicate that the alien tunicate P. praeputialis was a better or superior bio-engineer when compared to the system constructed by the kelp L. nigrescens. Rather, each species was relevant and relied on different ecological mechanisms.

Keywords: Lessonia nigrescens; Pyura praeputialis; Ecopath; Ecosim; Loop Analysis model keystone indices (search for similar items in EconPapers)
Date: 2013
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (6)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0304380012005169
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:ecomod:v:250:y:2013:i:c:p:307-318

DOI: 10.1016/j.ecolmodel.2012.10.014

Access Statistics for this article

Ecological Modelling is currently edited by Brian D. Fath

More articles in Ecological Modelling from Elsevier
Bibliographic data for series maintained by Catherine Liu ().