A Global-Scale Evaluation of Mammalian Exposure and Vulnerability to Anthropogenic Climate Change
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A Global-Scale Evaluation of Mammalian Exposure and Vulnerability to Anthropogenic Climate Change Tanya L. Graham A Thesis in The Department of Geography, Planning and Environment Presented in Partial Fulfillment of the Requirements for the Degree of Master of Science (Geography, Urban and Environmental Studies) at Concordia University Montreal, Quebec, Canada March 2018 © Tanya L. Graham, 2018 Abstract A Global-Scale Evaluation of Mammalian Exposure and Vulnerability to Anthropogenic Climate Change Tanya L. Graham There is considerable evidence demonstrating that anthropogenic climate change is impacting species living in the wild. The vulnerability of a given species to such change may be understood as a combination of the magnitude of climate change to which the species is exposed, the sensitivity of the species to changes in climate, and the capacity of the species to adapt to climatic change. I used species distributions and estimates of expected changes in local temperatures per teratonne of carbon emissions to assess the exposure of terrestrial mammal species to human-induced climate change. I evaluated species vulnerability to climate change by combining expected local temperature changes with species conservation status, using the latter as a proxy for species sensitivity and adaptive capacity to climate change. I also performed a global-scale analysis to identify hotspots of mammalian vulnerability to climate change using expected temperature changes, species richness and average species threat level for each km2 across the globe. The average expected change in local annual average temperature for terrestrial mammal species is 1.85 oC/TtC. Highest temperature changes are expected for species living in high northern latitudes, while smaller changes are expected for species living in tropical locations. Hotspots of terrestrial mammalian vulnerability to climate change include northern Eurasia and Canada, central China, and the Amazon basin. This study is intended to provide a guide for conservation research and planning in the identification of individual mammal species as well as regions of mammalian habitat that may become increasingly vulnerable with continued climate change. iii Acknowledgements I would like to thank Dr. H. Damon Matthews (thesis supervisor), Dr. Pascale Biron (thesis committee member and internal examiner), Dr. Robert Weladji (thesis committee member), Dr. Jean-Philippe Lessard (external examiner) as well as the members of the Concordia Climate Science, Impacts and Mitigation Studies (C2SIMS) lab for their valuable feedback during the research and writing process. I also wish to thank Dr. Martin Leduc (for providing the climate model data for this project), as well as Dr. Daniel Naud, Donny Seto and Marco Burelli (for providing GIS technical support). This project was supported by funding from the Natural Sciences and Engineering Research Council of Canada (NSERC Alexander Graham Bell Canada Graduate Scholarship), the Fonds de Recherche Nature et Technologies Québec (FRNTQ Masters Research Scholarship), Hydro-Québec (Concordia University Hydro-Québec Bursary, Faculties of Arts & Science, Fine Arts, John Molson School of Business), the Concordia University Faculty of Arts and Science (Graduate Fellowship) and the Concordia School of Graduate Studies (Concordia University Special Entrance Award). iv Table of Contents List of Figures viii List of Tables ix Introduction 1 Chapter 1 - Literature Review 5 I. Overview 6 II. Climate Change 6 i. The Greenhouse Effect 6 ii. Observed Climate Changes 7 iii. Predicting Future Climate Changes 8 III. Climate Change and Earth’s Biota 9 i. The Importance of Climate for Terrestrial Mammal Species 9 ii. Observed Biological Responses to Recent Climate Change 11 iii. Anticipated Biological Impacts of Continued Climate Change 11 iv. Adaptation or Extinction? Assessing the Response of Species to Continued Climate Change 13 Chapter 2 - Research Objectives 15 Chapter 3 - Data Description 18 I. IUCN Spatial Data 19 i. IUCN Overview 19 ii. The IUCN Mapping Project 19 iii. Number of Polygons per Species Range 20 iv. Polygon Coding – Presence, Origin & Seasonality 22 II. IUCN Red List™ Status and Higher Taxonomy 28 III. Local Temperature Change per Tt of Carbon Emissions (RTCRE) 29 v Chapter 4 – Methods 32 I. Data Preparation 33 i. IUCN Data Preprocessing 33 Projection of IUCN Spatial Data 33 Join of IUCN Attribute Information to IUCN Spatial Data 34 Selection of IUCN Polygons for Analysis 35 Regrouping of IUCN Spatial Data by Mammal Order 41 ii. RTCRE Climate Model Data Preprocessing 41 Creation of a Point Shapefile of RTCRE Values 41 Transformation of RTCRE Point Data into a Continuous Surface 42 II. Determination of Spatially-Averaged RTCRE for Each Mammal Species 44 III. Determination of Global Hotspots of Mammalian Vulnerability to CO2-Induced Warming 46 i. Calculation of Species Richness per km2 46 ii. Calculation of the Average Species Threat Level per km2 46 iii. Calculation of a Climate Vulnerability Score per km2 48 Chapter 5 – Results 49 I. IUCN Data Statistics 50 i. Terrestrial Mammal Orders & Number of Species per Order 50 ii. Species per IUCN Red List™ Category (All Mammals) 52 iii. Spatial Distribution of Threat Categories (All Mammals) 54 iv. Species per IUCN Red List™ Category (by Mammal Order) 56 II. Local Temperature Changes per Tt of Carbon Emissions (RTCRE) for Terrestrial Mammal Species 61 i. Statistical Overview (All Mammals) 61 ii. Species per 0.5 oC/TtC Range of RTCRE Values 61 iii. RTCRE Values by IUCN Red List™ Category 63 Overview 63 RTCRE Values for Data Deficient Species 65 RTCRE Values for Non-Threatened Species 66 vi RTCRE Values for Threatened Species 68 iv. RTCRE Values by Mammal Order 71 III. Global Hotspots of Mammalian Vulnerability to Climate Change 74 i. Species Richness per km2 74 ii. Average Species Threat Level per km2 76 iii. Climate Vulnerability Score per km2 78 Chapter 6 – Discussion 79 I. Overview 80 II. Vulnerability to Climate Change due to Magnitude of Exposure 81 i. Temperature Changes by Species Range 81 ii. Temperature Changes by Red List™ Category 81 iii. Temperature Changes by Mammal Order 82 III. Vulnerability to Climate Change due to High Local Species Density 83 IV. Vulnerability to Climate Change due to High Local Average Threat Level 84 V. Hotspots of Vulnerability to Climate Change 84 VI. Limitations and Future Research 85 Conclusion 86 References 88 Appendix 99 vii List of Figures Chapter 3 - Data Description Figure 3-1. Inverse logarithmic relationship between the number of species and the number of polygons used to map their distributions 22 Figure 3-2. Number of polygons per category of species presence coding 24 Figure 3-3. Number of polygons per category of species origin coding 26 Figure 3-4. Number of polygons per category of species seasonality coding 27 Figure 3-5. Global distribution of local temperature changes in oC per Tt of carbon emissions (RTCRE) 31 Chapter 4 - Methods Figure 4-1. The IUCN terrestrial mammals shapefile in the geographic coordinate system 33 Figure 4-2. The IUCN terrestrial mammals shapefile in the World Goode Homolosine Land projection 34 Figure 4-3. Creating a continuous raster surface of RTCRE values from a vector point layer 43 Figure 4-4. Overlap of a species range and RTCRE values 45 Figure 4-5. Non-spatially contiguous polygons representing portions of the range of a single species 45 Chapter 5 - Results Figure 5-1. Number and percentage of terrestrial mammal species per IUCN Red List™ category 53 Figure 5-2. The spatial distribution of terrestrial mammal species by IUCN Red List™ category 55 Figure 5-3. RTCRE values plotted by IUCN Red List™ category 64 Figure 5-4. Number of terrestrial mammal species per km2 76 2 Figure 5-5. Average species threat level per km 77 Figure 5-6. Climate vulnerability score per km2 78 viii List of Tables Chapter 3 - Data Description Table 3-1. Number and percentage of polygons mapped per individual and/or organization in the IUCN terrestrial mammals spatial dataset 20 Table 3-2. Number and percentage of species per range of number of polygons used to map species distributions 21 Table 3-3. Number and percentage of polygons for each category of species presence coding in the IUCN terrestrial mammals spatial dataset 23 Table 3-4. Number and percentage of polygons for each category of species origin coding in the IUCN terrestrial mammals spatial dataset 25 Table 3-5. Number and percentage of polygons for each category of species seasonality coding in the IUCN terrestrial mammals spatial dataset 27 Table 3-6. The IUCN Red List™ classification scheme 29 Chapter 4 - Methods Table 4-1. Species excluded based on presence uncertainty 36 Table 4-2. Species excluded due to non-native origins 37 Table 4-3. Minimum, maximum and total number of polygons used to map species ranges within a given mammal order 38 Table 4-4. Minimum, maximum and mean polygon areas per mammal order 39 Table 4-5. Numerical weights assigned to each Red List™ category 47 Chapter 5 - Results Table 5-1. Mammal orders and the number of species per order 51 Table 5-2. Number and percentage of terrestrial mammal species per IUCN Red List™ category 52 Table 5-3. Number of species per IUCN Red List™ category for each terrestrial mammal order 58 Table 5-4. Percentage of species per IUCN Red List™ category for each terrestrial mammal order 59 Table 5-5. Number and percentage of non-threatened and threatened species per mammal order 60 ix Table 5-6. Number and percentage of species per 0.5 oC/TtC range of RTCRE values 62 Table 5-7. Species with an RTCRE of > 4.0oC/TtC 62 Table 5-8. Mean, minimum, maximum and range of RTCRE values per IUCN Red List™ category, as well as the number and percentage of species per category whose RTCRE value exceeds the terrestrial mammal average of 1.85 oC/TtC.