Biodiversity Oases in the Southern Tundra: The Role of shrub-herbaceous communities (Western Siberia)

The southwestern Gydan Peninsula remains a significant data gap in understanding tundra ecosystem responses to climate change and shrub expansion. Detailed studies linking plant community composition to soil properties in this region are critically lacking. This study provides the integrated analysis of shrub-herbaceous communities and their underlying soils in this region. Based on comprehensive geobotanical and soil surveys at 52 sites, we identified four distinct community types using multivariate analysis. Our results reveal a clear hierarchy of environmental drivers. Primary vegetation patterns and the formation of biodiversity hotspots, including the discovery of several plant species new to the local flora, are predominantly shaped by landscape heterogeneity, such as the mosaic of slopes, valleys, and snow hollows. Soil properties, notably those related to texture, active layer dynamics, and hydromorphy, act as significant secondary filters, structuring communities along a key soil gradient. However, the overall correlation between soil and vegetation matrices was limited, indicating a substantial role for other unmeasured factors. We conclude that plant community assembly in the southern Gydan tundra is governed by an interplay where the geomorphic template sets the stage for diversity, while localized soil conditions fine-tune composition. These findings establish an essential baseline for monitoring and underscore that conserving landscape heterogeneity is crucial for the resilience of these rapidly changing Arctic ecosystems.