Stefan Wirtz Vom Fachbereich VI (Geographie/Geowissenschaften ...

Experimentelle Rinnenerosionsforschung vs. Modellkonzepte – Quantifizierung der hydraulischen und erosiven Wirksamkeit von Rinnen
- Embedded rock fragments appear to be resistant against goat trampling until the
passing of approx. 300 animals.
- Rock fragments that rest loosely on top of the soil surface are prone to be moved by
animal hooves even at low slope angles.
- Crusted soil surfaces provide a high amount of detachable fine material once the crust
is destroyed livestock trampling.
- The provided fine material can be eroded by overland flow within a short time, and is
immediately available for wind erosion processes, too.
- The experimental methods have proven to be suitable for the determination of areaand
animal-number-related rates that are surprising in their magnitude. Nevertheless,
the methods require further validation and development.
The results of the present study support the conclusion that sheep and goat erosion is a
severely underestimated problem.
Acknowledgement
We want to thank all students and the voluntary assistants for their work during the field trip.
Special thanks go to Guidobaldo Hernandez Vico, the herder of the “erosion-goats”. He
provided the goats and he was the only person who was able to keep the 15 crazy critters
under control.
References
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FREITAS, H., VRAHNAKIS, M., LARROSI, D. & CABEZUDO, B. (2004): Change in
plant spatial patterns and diversity along the successional gradient of Mediterranean
grazing ecosystems. - Ecological Modelling 180: 523-535.
ANDRESEN, H., BAKKER, J.P., BRONGERS, M., HEYDEMANN, B. & IRMLER, U.
(1990): Long – term changes of salt marsh communities by cattle grazing. – Vegetatio 89:
137-148.
BARBIER, N., COUTERON, P., LEJOLY, J., DEBLAUWE, V. & LEJEUNE, O. (2006):
Self-organized vegetation patterning as a fingerprint of climate and human impact on
semi-arid ecosystems. – J. Ecol., 94: 537-547.
BOONKORKUEA, N., LENBURY, Y., ALVARADO, F.J. & WOLLKIND, D.J. (2010):
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Journal of Biological Dynamics 4, 4: 346-380.
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