TY - JOUR
T1 - The pervasive and multifaceted influence of biocrusts on water in the world's drylands
AU - Eldridge, David J.
AU - Reed, Sasha
AU - Travers, Samantha K.
AU - Bowker, Matthew A.
AU - Maestre, Fernando T.
AU - Ding, Jingyi
AU - Havrilla, Caroline
AU - Rodriguez-Caballero, Emilio
AU - Barger, Nichole
AU - Weber, Bettina
AU - Antoninka, Anita
AU - Belnap, Jayne
AU - Chaudhary, Bala
AU - Faist, Akasha
AU - Ferrenberg, Scott
AU - Huber-Sannwald, Elisabeth
AU - Malam Issa, Oumarou
AU - Zhao, Yunge
N1 - Publisher Copyright:
© 2020 John Wiley & Sons Ltd
PY - 2020/10/1
Y1 - 2020/10/1
N2 - The capture and use of water are critically important in drylands, which collectively constitute Earth's largest biome. Drylands will likely experience lower and more unreliable rainfall as climatic conditions change over the next century. Dryland soils support a rich community of microphytic organisms (biocrusts), which are critically important because they regulate the delivery and retention of water. Yet despite their hydrological significance, a global synthesis of their effects on hydrology is lacking. We synthesized 2,997 observations from 109 publications to explore how biocrusts affected five hydrological processes (times to ponding and runoff, early [sorptivity] and final [infiltration] stages of water flow into soil, and the rate or volume of runoff) and two hydrological outcomes (moisture storage, sediment production). We found that increasing biocrust cover reduced the time for water to pond on the surface (−40%) and commence runoff (−33%), and reduced infiltration (−34%) and sediment production (−68%). Greater biocrust cover had no significant effect on sorptivity or runoff rate/amount, but increased moisture storage (+14%). Infiltration declined most (−56%) at fine scales, and moisture storage was greatest (+36%) at large scales. Effects of biocrust type (cyanobacteria, lichen, moss, mixed), soil texture (sand, loam, clay), and climatic zone (arid, semiarid, dry subhumid) were nuanced. Our synthesis provides novel insights into the magnitude, processes, and contexts of biocrust effects in drylands. This information is critical to improve our capacity to manage dwindling dryland water supplies as Earth becomes hotter and drier.
AB - The capture and use of water are critically important in drylands, which collectively constitute Earth's largest biome. Drylands will likely experience lower and more unreliable rainfall as climatic conditions change over the next century. Dryland soils support a rich community of microphytic organisms (biocrusts), which are critically important because they regulate the delivery and retention of water. Yet despite their hydrological significance, a global synthesis of their effects on hydrology is lacking. We synthesized 2,997 observations from 109 publications to explore how biocrusts affected five hydrological processes (times to ponding and runoff, early [sorptivity] and final [infiltration] stages of water flow into soil, and the rate or volume of runoff) and two hydrological outcomes (moisture storage, sediment production). We found that increasing biocrust cover reduced the time for water to pond on the surface (−40%) and commence runoff (−33%), and reduced infiltration (−34%) and sediment production (−68%). Greater biocrust cover had no significant effect on sorptivity or runoff rate/amount, but increased moisture storage (+14%). Infiltration declined most (−56%) at fine scales, and moisture storage was greatest (+36%) at large scales. Effects of biocrust type (cyanobacteria, lichen, moss, mixed), soil texture (sand, loam, clay), and climatic zone (arid, semiarid, dry subhumid) were nuanced. Our synthesis provides novel insights into the magnitude, processes, and contexts of biocrust effects in drylands. This information is critical to improve our capacity to manage dwindling dryland water supplies as Earth becomes hotter and drier.
KW - biological soil crust
KW - bryophyte
KW - cryptogam
KW - cyanobacteria
KW - hydrological cycle
KW - infiltration
KW - lichen
KW - sediment production
KW - soil hydrology
KW - soil moisture
UR - http://www.scopus.com/inward/record.url?scp=85088790999&partnerID=8YFLogxK
U2 - 10.1111/gcb.15232
DO - 10.1111/gcb.15232
M3 - Article
C2 - 32729653
AN - SCOPUS:85088790999
SN - 1354-1013
VL - 26
SP - 6003
EP - 6014
JO - Global change biology
JF - Global change biology
IS - 10
ER -