Topography-based metrics for climate-change microrefugia: topodiversity, glaciers, wetlands, cool slopes in British Columbia (Version 2.1)

Suggested citation: Kehm, G. 2026. Topography-based metrics for climate-change microrefugia: topodiversity, glaciers, wetlands, cool slopes in British Columbia (Version 2.1). Place of publication: GKA Geographic Solutions Inc., Vancouver, BC. doi: 10.5281/zenodo.18990506 Map example images: A) Macro Land Forms of British Columbia map B) Topo diversity of British Columbia map Summary: The physical landscape plays a significant role in determining where biodiversity can exist, with its influence over the distribution of habitat types. The heterogeneity in physical combinations of land form, slope, soils, hydrology, geology and altitude results in a diversity of climates such that species can make smaller spatial adjustments to track suitable habitat and climatic conditions (Laurence et al., 2021); Carroll et al., 2017; Littlefield et al., 2017). While physical diversity focuses on the non-living aspects of the Earth, it is closely linked to biodiversity, as the abiotic foundation plays a key role in the distribution and survival of species. Due to the slow, enduring qualities of the physical landscape containing high physical diversity, conserving large areas of high physical diversity can maintain the future persistence of suitable climatic conditions for species survival (Hannah et al., 2007; Loarie et al., 2009). Physical environmental diversity includes both topodiversity and geodiversity. Both terms are often used interchangeably and describe different combinations of physical features with implications for biodiversity conservation. Geodiversity, also referred to as enduring features, encompasses the natural range of geological, geomorphological, landform, pedological (soils), and hydrological features and processes. This is an inclusive term capturing a matrix of attributes in the landscape that support biodiversity, broadly covering ecologically meaningful groupings of geology, landform, and altitude. Geodiversity examples include ‘mid-elevation toe slope on calcareous bedrock’ or ‘low elevation dry flats on thick glacial fluvial sediment’. Geodiversity is useful as an input into processes for identifying new conservation lands, assessing the representative biodiversity contributions of existing conservation lands, and stratifying field sampling designs. Topodiversity is the variety and abundance of landforms and terrain, including hydrological complexes like wetlands, lakes, rivers and streams. Landform examples include islands, north-facing sideslopes, toe slopes, cliffs and ridge lines. Topodiversity metrics are useful in identifying climate-change microrefugia for conservation planning and management. Topographic diversity is highly correlated with reduced climate change impacts in protected areas worldwide (Lawrence, A. 2021). The conservation of some ecologically important taxa, such as bee pollinators, may be aided in site prioritization using topodiversity metrics (Doherty, K. 2021). A topodiversity (and geodiversity) analysis, supported by climate change refugial characteristics of cool, landform types, will help increase the resilience of conservation planning actions over time. Additional benefits of applying topodiversity analyses include: --Helping to inform decisions and management of resource development projects in ‘special management areas’ by supporting precautionary principles of minimizing environmental impacts.--Additional information for input into spatial analyses identifying important priority areas in land use or watershed-based planning processes.--Provide additional leverage for decision makers when arguing against land conversion/extractive processes in specific areas.This dataset applies the Gini-Simpson diversity using the Fragstats function in the QGIS application (Serena Pallecchi, re. McGarigal, K., and B. J. Marks). This is the oldest and simplest method to measure biodiversity. It is relatively less sensitive to richness and thus rare patch types, as it highlights relative species abundance. Versioning: The previous version of the topodiversity index (2.0) is based on a Shannon Diversity Index (GSDI), which is good at tracking rarity. The Gini-Simpson Diversity Index (GSDI) is applied in this latest revision (V2.1) to improve the classification scalability across the province of British Columbia and at larger map scales. Approach: This dataset applies the Gini-Simpson diversity index (GSDI) using the r.li.simpson function in the QGIS V3.4 application (Serena Pallecchi, ref. McGarigal, K., and B. J. Marks Fragstats V4.3). This is the oldest and simplest method to measure biodiversity. It is relatively less sensitive to richness and thus rare patch types, as it highlights relative species abundance. The software was used with the following analysis parameters: a) 8-cell neighbourhood rule b) Sampling strategy Moving Window without kernel weighting (8-cell, square shape with side length of 350m). Values range from -1.73 to 2.19 (highest diversity). c) Moving window search radii: Several Fragstat Gini-Simpson and Shannon diversity index search radii were run and qualitatively evaluated using the following distances (meters): 200, 300, 350, 400, 1000. The GSDI with a 1000m 8-cell moving window search radius distance appears to capture the extent of diverse and adjacent macro land forms at the scale of the province without exaggerating representation (both under or over) of high topodiversity areas based on macro land forms, and maintaining connectivity between high diversity areas (i.e. along a lateral moraine). The size of your study area and your project goals will influence which diversity index to use and the parameter values to assign when creating it. Processing for the GSDI: ArcGIS Desktop Pro software symbolizes the GSDI with three classes using a Geometric Area Classification to maintain the smaller areas with the highest diversity classes. GSDI three-class value ranges: Lowest diversity class 1: 0.001 - 0.572 Low/Moderate diversity class 2: 0.573 - 0.827 Highest diversity class 3: 0.828 - 0.94 The original input macro land form data set is available to download as a Map Layer Package or a Geotiff file here: https://zenodo.org/records/15685110 Cooler macro land forms are available as a reclass from the dataset above and provide a mask to focus on potential high, cool, physically diverse places. The map packages (instead of GeoTIFF files) contain complete legend styling.