Use of hierarchical designs to detect scales of heterogeneity in the invasive species &lt;em&gt;Sargassum muticum&lt;/em&gt;

Celia Olabarria,Ivan F Rodil,Francesca Rossi,Jesús S Troncoso,Patricia Quintas

doi:10.3989/scimar.2009.73n3507

Use of hierarchical designs to detect scales of heterogeneity in the invasive species <em>Sargassum muticum</em>

Celia Olabarria, Ivan F Rodil + Show 3 more

Open Access

https://doi.org/10.3989/scimar.2009.73n3507

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Journal: Scientia Marina	Publication Date: Apr 27, 2009
Citations: 20	License type: cc-by

Affiliation: Universidade de Vigo, University of Coimbra

Abstract

Invasion of alien species poses serious threats to many ecosystems. Despite the potential of Sargassum muticum to spread and invade new areas, no attention has been given to the study of variability of structural or morphological features across different spatial scales. We employed a hierarchical sampling design to examine patterns of spatial variability of fertility and morphological variables of S. muticum over different spatial scales (quadrats, sites, locations, rias) ranging from metres to tens of kilometres We repeated the sampling in March, April and July to test for the consistency of patterns through time. There was no variability between rias (tens of kilometres apart), but substantial differences occurred at the other scales examined. Fertility and percent cover varied between locations (1.5-3 km apart), whereas morphological variables varied between sites (tens of metres apart) and quadrats (metres apart). Furthermore, patterns of variation were not consistent over time. The study demonstrated the importance of a multi-scale sampling programme for monitoring seaweed invasion.

Highlights

Alien seaweeds and plants have increasingly arrived in new areas during the last few decades (Verlaque, 2001)
We examined patterns of variability of percent cover, fertility, size of primary lateral and total number of laterals of S. muticum over a variety of spatial scales, ranging from metres to tens of kilometres, and the consistency of these patterns over time
For fertility and percent cover, the largest variation was found at the scale of quadrats within sites, whereas morphological variables showed the largest variation at the scale of thalli within quadrats

Summary

Introduction

Alien seaweeds and plants have increasingly arrived in new areas during the last few decades (Verlaque, 2001). Alien species are widely recognised as important agents of global change, and can colonise new habitats and even cause local extinction of native species (Vitousek et al, 1997). A primary recommendation for designing monitoring programmes for effective habitat protection and restoration is that they should be based on sampling schemes at the spatial and temporal scales that characterise population and community dynamics of the species of interest. Hierarchical sampling programmes can identify these patterns of variability and provide the necessary information for effective monitoring programmes (e.g. Underwood and Chapman, 1998)

Methods

Results

Discussion

Conclusion