As cities expand at an unprecedented pace, ecological networks become fragmented and the capacity of landscapes to sustain biodiversity diminishes. Metro Vancouver presents a compelling case: a region defined by a spectacular natural setting yet increasingly constrained by population growth, housing densification, and limited land availability.
Ecological resilience within cities depends not only on the total amount of green space, but on its spatial configuration and connectivity. Well-connected green areas allow species to move, exchange genes, and perform vital ecological functions such as pollination, seed dispersal, and carbon storage. Private lands including residential gardens, backyards, institutional campuses, and commercial landscapes cover a significant portion of the city yet remain underexplored in most ecological assessments. This research examines how public and private green spaces together shape the ecological landscape of Metro Vancouver, using spatial analysis and resistance-based connectivity modelling to assess fragmentation and connectivity across the metropolitan region between 2014 and 2020.
Research Objectives
- Quantify the contribution of private green spaces to Metro Vancouver's total urban green space and measure change between 2014 and 2020.
- Analyze green-space fragmentation using patch size, patch density, edge density, and clustering metrics, with attention to linkages between public and private patches.
- Model ecological connectivity for species movement using circuit theory to identify key corridors and resistance zones within the urban landscape.
The study area encompasses the Metro Vancouver Regional District (MVRD) in southwestern British Columbia, spanning approximately 49.00 to 49.35 degrees N and 122.65 to 123.20 degrees W. The region includes highly urbanized municipalities such as Vancouver, Burnaby, and Surrey, as well as peri-urban landscapes bordering the Fraser River delta and the North Shore Mountains. Rural areas including Electoral Area A, Bowen Island, and Lions Bay are excluded from the analysis.
Primary Datasets
| Dataset | Year | Resolution |
|---|---|---|
| MV Regional Boundary | 2023 | 1:20,000 |
| Land Cover Classification | 2014 | 5 m raster |
| Land Cover Classification | 2020 | 5 m raster |
| Parcel Map BC Polygons | 2023 | Parcel-level |
The study applies a structured geospatial analytical framework integrating land cover processing, ownership classification, fragmentation analysis, and resistance-based connectivity modelling. All spatial analyses are conducted in ArcGIS Pro, R (version 4.5), and Google Earth Engine. Land cover rasters for 2014 and 2020 are projected to NAD83/UTM Zone 10N, clipped to the study boundary, and aligned to a common resolution. Ownership masks generate tenure-specific rasters for private and public lands. Vegetation composition is quantified via zonal statistics; fragmentation metrics including patch density, edge density, mean patch area, effective mesh size, cohesion index, and clumping index are calculated using the landscapemetrics package in R with 8-neighbour cell connectivity. Functional connectivity is modelled for 2020 using species-specific resistance surfaces derived from the 16-class land cover scheme, with accumulated cost distances transformed into continuous probability-of-connectivity surfaces via an exponential decay function, applied to four focal species representing distinct mobility guilds.
Focal Species
Land Cover Transitions (2014–2020)
Substantial vegetation conversion occurs across Metro Vancouver between 2014 and 2020. Coniferous forest declines by 2,901 ha (5.75%) and deciduous forest by 4,184 ha (11.13%), producing a net regional forest loss of 3,962 ha (4.50%). In contrast, shrubland increases by 3,757 ha (115.79%) and natural grass/herb by 3,118 ha (84.48%). Forest remains the dominant land cover type despite net loss, while grey infrastructure records a net gain over the study period.
Vegetation Change by Tenure
Private lands record a slight net gain in total vegetation (+1,047 ha, 1.5%), while public lands show a small net loss (161 ha, 0.4%). Private coniferous forest declines by 2,172 ha (18.2%), whereas public coniferous forest falls more modestly by 171 ha (0.8%). Shrub and natural grass areas expand markedly on both tenure types, with private shrub gaining 2,007 ha (106%) and public shrub gaining 965 ha (99%). Forest loss occurs in 19 of 22 municipalities, with the greatest absolute losses in Delta (627 ha, 22.3%), Langley Township (589 ha), Surrey (537 ha), and Pitt Meadows (434 ha, 26.0%). Gains are recorded only in the City of Vancouver (+145 ha, 5.2%), City of Langley (+17 ha), and White Rock (+0.2 ha).
Landscape Fragmentation
Private lands remain highly fragmented throughout the study period. Mean patch area increases from 0.091 ha to 0.109 ha, while total patch count holds near 351,000. Public lands support larger and better-aggregated networks: mean patch area rises from 0.360 ha to 0.449 ha, and patch count declines from 102,574 to 95,931, indicating consolidation of green space. Edge density decreases on both tenure types, from 163 to 104 m/ha on private lands and from 121 to 89 m/ha on public lands.
Ecological Connectivity
Connectivity modelling across four urban-adapted species reveals distinct spatial patterns in landscape permeability. High connectivity values are concentrated in northern and eastern municipalities, while low values dominate the urban core of Vancouver, Burnaby, Richmond, and Surrey. Across all four focal species, private lands consistently hold the largest share of high-connectivity habitat. Government lands contribute 24 to 33% of high-connectivity area, with private-to-government connectivity ratios ranging from 1.28 (Black-capped Chickadee) to 2.12 (Grey Squirrel).
Tenure-Based Connectivity
Across all four focal species, private lands consistently hold the largest share of high-connectivity habitat. Government lands contribute 24 to 33% of high-connectivity area, while private lands account for the majority in every species model. Private-to-government connectivity ratios range from 1.28 (Black-capped Chickadee) to 2.12 (Grey Squirrel), underscoring the disproportionate ecological importance of privately owned green space in the urban landscape.
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