Exploring some relationships between biological soil crusts, soil aggregation and wind erosion
Citation
David J Eldridge, and John F Leys, Exploring some relationships between biological soil crusts, soil aggregation and wind erosion: .
Summary
A portable wind tunnel was used to test the contribution of biological and physical elements to overall soil aggregation on a soil dominated by biological soil crusts in south-eastern Australia. After moderate disturbance and simulated wind erosion, 90% of surface aggregates on the loamy soil and 76% on the sandy soil were dominated by biological elements (cryptogams). Lower levels of biological bonding were observed on the severely disturbed treatment. Linear regression indicated a significant positive relationship (r2=0·72) between biological soil crust cover and dry aggregation levels greater than 0·85mm. To maintain sediment transport below an erosion control target of 5gm−1s−1 for a 65kmh−1 wind at 10m height, a crust [...]
Summary
A portable wind tunnel was used to test the contribution of biological
and physical elements to overall soil aggregation on a soil dominated by
biological soil crusts in south-eastern Australia. After moderate
disturbance and simulated wind erosion, 90% of surface aggregates on the
loamy soil and 76% on the sandy soil were dominated by biological
elements (cryptogams). Lower levels of biological bonding were observed
on the severely disturbed treatment. Linear regression indicated a
significant positive relationship (r2=0·72) between
biological soil crust cover and dry aggregation levels greater than
0·85mm. To maintain sediment transport below an erosion
control target of 5gm−1s−1 for a
65kmh−1 wind at 10m height, a crust cover of
approximately 20% is required. When a multiple regression model which
sequentially fitted biological crust cover and dry aggregation greater
than 0·85mm was applied to the data, dry aggregation
accounted for more of the variation in sediment transport rate than
biological crust cover. These data were used to develop a conceptual
model which integrates crust cover and dry aggregation, and provides a
useful framework within which to predict the likely impacts of changes
in soil crust cover and aggregation. Published in Journal of Arid
Environments, volume 53, issue 4, on pages 457 - 466, in 2003.
