The diversity of habitats within a tropical seascape is a metric of ecosystem biodiversity. Coral reefs and associated habitats are ideal for mapping with remotely sensed imagery because they are shallow and have high water clarity. MSEL has been involved in assessing the level of habitat detail and accuracy that can be derived from different remote sensing platforms, improving processing methodologies, and developing classification schemes. A key goal of the research group is to try and develop better ways of utilising habitat maps for addressing ecological problems (‘seascape ecology’).
<a href=”http://www.marinespatialecologylab.org/wp-content/uploads/2010/11/Figure-1-redone.jpg”><img class=”alignnone size-medium wp-image-435″ title=”remote sensing example” alt=”” src=”http://www.marinespatialecologylab.org/wp-content/uploads/2010/11/Figure-1-redone-300×225.jpg” width=”270″ height=”202″ /></a><a href=”http://www.marinespatialecologylab.org/wp-content/uploads/2010/11/groundtruthing.jpg”><img class=”alignnone size-medium wp-image-436″ title=”groundtruthing” alt=”” src=”http://www.marinespatialecologylab.org/wp-content/uploads/2010/11/groundtruthing-300×188.jpg” width=”289″ height=”183″ /></a><a href=”http://www.marinespatialecologylab.org/wp-content/uploads/2010/11/rs-resolution-resized2.jpg”><img class=”alignnone size-medium wp-image-437″ title=”rs resolution resized2″ alt=”” src=”http://www.marinespatialecologylab.org/wp-content/uploads/2010/11/rs-resolution-resized2-283×300.jpg” width=”174″ height=”185″ /></a>
MSEL has pioneered the use of marine habitat maps for mapping and understanding patterns of beta diversity. Beta diversity is an important concept in biodiversity and represents species ‘turnover’. Beta diversity (the change of species and species’ abundances) can be measured at a range of scales, but we assessed beta diversity among habitat types. By combining habitat maps and species data collected in the field, a map of diversity can be generated by passing a ‘window’ of any size across the seascape and calculating the number of different habitat types and how different those habitats are from each other. This highlights ‘hot-spots’ of beta diversity. Because beta diversity is quantified in two-dimensions, it can be related to various biophysical drivers. We demonstrated that reef beta diversity is particularly driven by variations in depth and wave exposure.
<a href=”http://www.marinespatialecologylab.org/wp-content/uploads/2010/11/figure-2_no-text-copy.jpg”><img class=”size-medium wp-image-438 alignnone” title=”figure 2_no text copy” alt=”” src=”http://www.marinespatialecologylab.org/wp-content/uploads/2010/11/figure-2_no-text-copy-300×225.jpg” width=”415″ height=”311″ /></a> <em>Habitat map of St John (U.S. Virgin Islands) (top) and map of its beta diversity (bottom).</em>
It is easy to imagine that the ecological communities in each habitat type seen on a map are very similar. Whether this is true or not is important for planning networks of marine reserves: if the communities are similar, protecting an example of each habitat type should capture most of the biodiversity. However, if communities vary significantly among patches of the same habitat type, the same habitat will need to be replicated multiple times in a reserve network. MSEL have demonstrated that fish communities do vary significantly among patches of the same habitat, particularly among biodiverse habitats such as coral-rich forereefs.
<a href=”http://www.marinespatialecologylab.org/wp-content/uploads/2010/11/Copy-of-P1020473.jpg”><img class=”alignnone size-medium wp-image-439″ title=”Copy of P1020473″ alt=”” src=”http://www.marinespatialecologylab.org/wp-content/uploads/2010/11/Copy-of-P1020473-300×197.jpg” width=”300″ height=”197″ /></a><a href=”http://www.marinespatialecologylab.org/wp-content/uploads/2010/11/Copy-of-P1020432.jpg”><img class=”alignnone size-medium wp-image-442″ title=”Copy of P1020432″ alt=”” src=”http://www.marinespatialecologylab.org/wp-content/uploads/2010/11/Copy-of-P1020432-300×225.jpg” width=”263″ height=”198″ /></a><a href=”http://www.marinespatialecologylab.org/wp-content/uploads/2010/11/DSCN6035.jpg”><img class=”alignnone size-medium wp-image-443″ title=”DSCN6035″ alt=”” src=”http://www.marinespatialecologylab.org/wp-content/uploads/2010/11/DSCN6035-300×225.jpg” width=”264″ height=”198″ /></a>
<strong>For more information see the papers of Harborne and Mumby.</strong>