Endemism hotspots in the flora of Belize

This thesis is aimed at improving the understanding of endemism (or ‘bioquality’) hotspots (areas where globally rare species are concentrated) within the flora of Belize, with a view to informing conservation priorities at scales suitable for practical land management. Research is framed within a standardised bioquality scoring system, whereby all species are allocated to ‘Star’ categories of global rarity. Based on this, the bioquality of different areas can be calculated and compared. Areas of high bioquality are considered priorities for conservation.
Chapter 1 discusses biodiversity loss and provides an overview of conservation prioritization exercises at various spatial scales, including Important Plant Areas and the assessment of bioquality within the Rapid Botanical Survey framework. This is followed by an overview of the study site which includes a brief history of vegetation research in Belize, and development of the National Protected Area System.
Chapter 2 describes the curation of a database of botanical records for Belize. Patterns in historical data are explored, revealing bias in the dataset; spatially, and in terms of taxonomic groups and habit types. Parts of Belize are found to be under-sampled. Areas close to settlements, research stations, and unusual geomorphological features are associated with high numbers of botanical records. Chapter 3 examines distribution patterns in observed bioquality data to determine how these relate to underlying geology and topographic diversity. A high percentage of hotspots are found on rugged limestone at mid - high elevations, and where there are transitions in underlying geology. Chapters 4 and 5 use two modelling methods to predict bioquality at a 1 km grid square resolution. Chapter 4 describes a bottom-up approach to predicting bioquality, based on stacking individual species distribution models (SSDM). Results show affinities to observed bioquality patterns, but a general tendency to over inflate bioquality. Chapter 5 describes the use of a top-down, macroecological (MEM) approach to modelling bioquality. This method produced more accurate predictions than those arising from the SSDM model. Three main areas where hotspots overlap on the SSDM and MEM maps (the western end of the Colombia River Forest Reserve, including Little Quartz Ridge and the Burgos Plateau; on the Vaca Plateau, near the border with Guatemala and eastwards into the Chiquibul Forest Reserve; and the limestone foothills on the eastern side of the Maya Mountains, in the Bladen Nature Reserve) are considered priorities for further research (in situ sampling).
In the concluding chapter, hotspot predictions are examined within the context of the national protected areas system of Belize. Several areas that were predicted as high bioquality occur in places where there is currently little or no on-the-ground management. Several suggested refinements for the methodology are presented, and this chapter concludes with recommendations for the development of a national strategy for plant conservation.

Keywords: plant conservation
bioquality
conservation priorities
plants
Belize
endemism
biodiversity conservation
Advisor: Hawthorne, W
Harris, D