The McMurdo Dry Valleys have no rainfall and most snowfall sublimates before wetting the soils significantly. Glacial melt streams are also seasonal, flowing for only 4 to 6 weeks per year. Consequently, hydrology does not provide significant connections among ecosystem components. Conversely, wind is a persistent daily feature of the McMurdo Dry Valleys environment throughout the year. In summer, cool air from the ice-covered oceans flows into the relatively warm valleys creating a strong thermal gradient in the valleys. Intense katabatic winds, a common feature of the winter months, sweep down the Antarctic Ice Sheet reaching speeds of 37 m s-1 in the MCM. These winds transport soils, fluvial material, and associated organic matter across all landscapes including the glaciers. The sediment darkens the glaciers, resulting in elevated meltwater fluxes to the streams in lakes enhancing local hydrologic connectivity. This valley-wide dispersal plays an important role in structuring biodiversity within the ecosystem. Aeolian deposition, in concert with the local selection pressure produces a mosaic of growth habitats throughout the MCM. For example, the glaciers are inoculated with sediment and attached biota forming small ice-bound liquid water habitats that support a relatively high diversity or organisms. Similar high diversity liquid water habitats are found within the permanent ice covers of the lakes within the valley, which eventually seeds the lakewater beneath the ice cover. Stoichiometric relationships in aeolian material also show that wind has a role in the spatial distribution of C:N:P ratios within the MCM. Owing to the slow microbial growth rates characteristic to the region, relative to the importance of aeolian dispersion, biological diversity must be viewed as being structured by both physical and biological processes.