Page 15 - September/October Outdoor Oklahoma Magazine

UNDER STRESS

Playas work best when surrounded by a native grass buffer that filters
out soil and agricultural contaminants and when there are no pits or
other modifications to the playa.
Filling in pits is one of the easiest ways to restore a playa. In most
cases, the spoil pile from the original excavation is present and used to
refill the pit. Once pits are refilled, rainwater and runoff can reach the Johnson says many playas
large cracks in a dry playa — which is essential for recharge to occur —
rather than collecting in the pit. The shallow water that collects in the have lost capacity to recharge
playa also supports the biodiversity function of the playa. groundwater and clean the
Johnson says many playas have lost capacity to recharge groundwa- water going down into the
ter and clean the water going down into the aquifer because they’re
clogged with sediment carried from cultivated fields by runoff. aquifer because they’re clogged
He recently studied sediment accumulation rates in several Kansas with sediment carried from
playas, from pre-agricultural times to now, and the research (Bowen and
Johnson, 2019) showed that “conversion of watersheds to cropland has cultivated fields by runoff .

greatly accelerated sediment accumulation within playas, which is gen-
erally resulting in a decline in critical playa ecosystem functions.”
Because playas are usually small and often dry, many producers till
through playas to plant crops. However, even if a playa is large enough
to be avoided, the surrounding upland is often farmed to the edge of
the playa, resulting in increased sediment accumulation in those playas.
In one study of Kansas playas, those in cropland had about 4 to 6
inches of accumulated sediment compared to about an inch in grass-
land playas. On average, playas within cropland watersheds that had no
buffer zones lost about 30 percent of their water storage capacity, while Water reaching the aquifer
those with grass buffers lost about 7 percent of storage capacity. The today began its journey during
study concludes that without grass buffers, accelerated sediment accu-
mulation in playas will continue, greatly reducing ecosystem functions, our parents’ and grandparents’
“and ultimately, many playas will disappear from the landscape.” lifetimes . And the water filling
Johnson, who co-authored the study, said establishing native grass
buffers around a playa is highly effective at reducing sediment accumu- playas now will be available from

lation and protecting playa functions. the aquifer for today’s children
Rainwater said, “We’re just trying to understand how these com-
plex processes on our planet work so that maybe we can have a and future generations .
better future.”
What is known is that healthy (unaltered or restored) playas filter
and clean the water going into the Ogallala aquifer. And it’s a con-
tinuous process. Water reaching the aquifer today began its journey
during our parents’ and grandparents’ lifetimes. And the water filling
playas now will be available from the aquifer for today’s children and
future generations.

For more information about playas, the benefits playas
provide, and programs to help conserve and restore pla-
yas, scan the code.

SEPTEMBER/OCTOBER 2022 13