Alkali sink

An alkali sink is a salty basin land form. In these depressions, which are found only in the San Joaquin Valley, California, rainwater drains to the basin and collects in areas where it cannot penetrate the soil due to a hard layer of clay or caliche, producing a pond or lake. When the water evaporates, it leaves behind increasing amounts of salt and minerals in the soil, creating a high pH level in the water and soil.

The term may also refer to a North American desert vegetation type (biome) characteristic of that landform.^[1] Plants that tolerate the extreme salt concentrations are known as halophytes. It is generally below the saltbrush scrub vegetation type, which is typified by less salt tolerant species than alkali sink types.

Halophytes that grow in and around alkali sinks:^[2]

Iodine Bush - Allenrolfea occidentalis
Bush Seepweed / Inkweed - Suaeda moquinii
Desert Saltgrass - Distichlis spicata
Alkali Weed - Cressa truxillensis
Alkali Heath - Frankenia salina
Parish's Glasswort - Arthrocnemum
Spikeweed / Tarweed - Centromadia pungens^[3]

References

^ Pam MacKay, Mojave Desert Wildflowers, 2nd Ed., p. 15-16
^ Comer, P.; Keeler-Wolf, T. (29 October 2022). "International Terrestrial Ecological System: California Central Valley Alkali Sink". NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer. NatureServe, Arlington, Virginia. Retrieved 17 February 2023.
^ "Arthrocnemum subterminale". The Calflora Database. Berkeley, California. 17 February 2023. Retrieved 17 February 2023.

[MDW-1] Pam MacKay, Mojave Desert Wildflowers, 2nd Ed., p. 15-16

[2] Comer, P.; Keeler-Wolf, T. (29 October 2022). "International Terrestrial Ecological System: California Central Valley Alkali Sink". NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer. NatureServe, Arlington, Virginia. Retrieved 17 February 2023.

[3] "Arthrocnemum subterminale". The Calflora Database. Berkeley, California. 17 February 2023. Retrieved 17 February 2023.