Aeolian impact on microinvertebrate propagule survival: A wind tunnel study

Authors: RIVAS, JOSE - University Of Texas - El Paso; Van Pelt, Robert - Scott; WALSH, ELIZABETH - University Of Texas - El Paso; GILL, THOMAS - University Of Texas - El Paso

Submitted to: Science of the Total Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/11/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Life is affected by the stresses of nature including heat and drought. Playa lakebeds are common in the arid and semi-arid regions of the world and are characterized by periods when they are filled with water and periods when the they are dry. Small, simple aquatic animals have developed strategies for reproducing rapidly when the water is present and for surviving the dry periods as resting stages or propagules. The communities of these simple animals are amazingly similar among playa basins within a region, suggesting dispersal. An ARS scientist along with university scientists conducted wind tunnel tests to investigate whether propagules of these simple animals could survive the forces of sandblasting and wind erosion and thus be dispersed by wind during the dry periods. We found that although many of the propagules were damaged and became inviable during the erosion process, other propagules could survive and come back to life when hydrated by rains in a favorable environment such as another playa.

Technical Abstract: Ephemeral wetland surfaces are preferential locations for wind erosion and repositories for resting stages (propagules) of aquatic microinvertebrates. Propagules can avoid pathogens and disperse to new habitats via wind entrainment (aeolian transport, anemochory). Atmospheric transport of invertebrate propagules has been documented at local and regional scales, but prior laboratory wind tunnel tests of propagule anemochory did not replicate the predominant natural process of wind erosion in drylands, saltation-sandblasting, nor determined the viability of experimentally wind-transported propagules. We used a soil erosion wind tunnel to test aeolian erosion, transport and subsequent viability of propagules from seven microinvertebrate species. A propagule-bearing crusted soil surface was formed, which was abraded by saltating silica sand in the wind tunnel to emit aeolian sand and dust. Sediment was collected from three downstream sections of the wind tunnel, representing different transport distances in the environment, and propagules were quantified for each section by species. The wind-eroded material was rehydrated with sterile media to detect hatching of any propagules which survived the sandblasting. Although survival was much lower than in a control experiment without wind tunnel treatment. We retrieved viable individuals of all tested species after hydration. The percentage of viable recovered propagules was similar to that reported for zoochory (animal-borne transport) and natural propagule banks. The results demonstrate that resting stages of many invertebrates can be wind-bombarded from natural surfaces along with sand and dust, dispersed into and transported through the atmosphere, and remain viable.