ÂÜÀòÉäÇø

You are encouraged to attend the defence. The details of the defence and attendance information is included below: &²Ô²ú²õ±è;

   

Date: August 7, 2025

Time: 2:00 PM to 5:00 PM (PT) 

 

Defence mode: Remote  

Virtual Attendance: via Zoom 

 

LINK TO JOIN: Please contact the Office of Graduate Administration for information regarding remote attendance for online defences. 

 

To ensure the defence proceeds with no interruptions, please mute your audio and video on entry and do not inadvertently share your screen. The meeting will be locked to entry 5 minutes after it begins: please ensure you are on time.  

 

Dissertation entitled: THE ROLE OF THE MATRIX IN SHAPING EXTINCTION RISK AND CONSERVATION OPPORTUNITIES FOR TERRESTRIAL MAMMALS

Abstract: The global biodiversity crisis, driven primarily by habitat loss and fragmentation, has traditionally led conservation efforts to focus almost exclusively on primary habitats. However, the ecological importance of the matrix, defined as areas surrounding primary habitat, has remained largely overlooked.

 

In this dissertation, I used global-scale spatial analyses coupled with statistical modeling to (i) quantify how matrix condition influences the impacts of habitat fragmentation on extinction risk for terrestrial mammals, (ii) compare the predictive performance of alternative habitat intactness models (patch-matrix, continuum, and hybrid models) for assessing extinction risk in terrestrial mammals, and (iii) map global patterns of terrestrial mammal species richness within the matrix to identify conservation opportunities beyond primary habitats.

 

My findings demonstrate that matrix condition significantly mediates the impacts of habitat fragmentation on extinction risk, with stronger predictive power than habitat loss or habitat amount alone. Moreover, I found that the predictive importance of fragmentation increases as matrix condition deteriorates, suggesting that managing or restoring the matrix represents a strategic conservation action for mitigating fragmentation's negative effects on biodiversity. Additionally, I found that hybrid habitat intactness models, which integrate discrete habitat patches with continuous gradients of habitat quality, consistently outperform traditional patch-matrix and continuum models, regardless of species’ habitat specialization. Notably, the magnitude of the relationship between habitat intactness and extinction risk was greater when employing hybrid models, highlighting that integrating discrete and continuous habitat representations can improve extinction risk analyses and provide valuable insights for conservation. My findings further reveal that hotspots of species richness within the matrix occupy only about 1% of Earth's terrestrial surface, yet could support more than half of all terrestrial mammal species. Importantly, these hotspots often face intense human pressures and remain inadequately represented within existing protected areas and other area-based conservation measures, underscoring their potential as strategic opportunities for biodiversity conservation.

 

Collectively, my results highlight an urgent need for a paradigm shift in conservation strategies that explicitly recognize, manage, and restore matrix areas as integral components of global biodiversity conservation. Integrating the matrix into conservation planning closely aligns with international biodiversity frameworks, particularly Target 2 of the Kunming-Montreal Global Biodiversity Framework, which calls for restoring at least 30% of degraded terrestrial ecosystems to enhance ecological integrity and connectivity. Such integration could substantially improve biodiversity outcomes, ecosystem resilience, and landscape connectivity, ultimately making critical contributions toward reversing global biodiversity declines

   

Defence Committee:  

Chair: Dr. David Connell  

Supervisor: Dr. Oscar Venter

Committee Member: Dr. Chris J. Johnson   

Committee Member: Dr. Moreno Di Marco

Committee Member: Dr. James E.M. Watson

External Examiner: Dr. Rob Serrouya