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Title: Assessment of Grazing Effect on Sheep Fescue (Festuca valesiaca)Dominated Steppe Rangelands in the semi-arid Central Anatolian Region of Turkey

Author
item FIRINCIOGLU, HUSEYIN - CENTRAL RES INST-TURKEY R
item SEEFELDT, STEVEN
item SAHIN, BILAL - GAZI UNIVERSITY-TURKEY
item VURAL, MECIT - GAZI UNIVERSITY-TURKEY

Submitted to: Journal of Arid Environments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/14/2009
Publication Date: 7/2/2009
Citation: Firincioglu, H.K., Seefeldt, S.S., Sahin, B., Vural, M. 2009. Assessment of Grazing Effect on Sheep Fescue (Festuca valesiaca)Dominated Steppe Rangelands in the semi-arid Central Anatolian Region of Turkey. Journal of Arid Environments. 73:1149-1157.

Interpretive Summary: Grazing pressure has increased over the last fifty years in the semi-arid Central Anatolian Region of Turkey. As a result, vegetation of the steppe rangelands has been severely degraded. In these pastures, Sheep fescue (Festuca valesiaca), a sod forming short-grass and Thymus sipyleus ssp rosulans (a prostrate shrub) are now the dominant species as these two plant species are exceptionally grazing tolerant. The presence of only these two dominant plant species, might be associated with an altered vegetation composition cause by the increased grazing pressure. Our objectives were to investigate the effects of grazing on steppe vegetation by determining: (1) Whether there are patterns in the vegetation, (2) How dominant species contribute to the patterns, and (3) How does the pattern in grazed vegetation differ from the pattern in ungrazed vegetation. The study was conducted in rangelands near the Field Crops Central Research Institute Experimental Station, 45 km southwest of Ankara, in 2003. Vegetation was studied in two types of grazing treatments (ungrazed and grazed) in flat and hilly areas. Protected areas had 14.3% more plant species, indicating that heavy grazing reduced the number of plant species. Grazing changed composition through decreasing total plant (25.6% less), grass (33.5% less), and Festuca valesiaca cover (41.8% less) while it substantially increased Thymus sipyleus basal cover (56% more). Three broad conclusions can be made: (1) Festuca valesiaca and Thymus sypileus had a significant effect in shaping of the vegetation pattern; (2) ungrazed pastures had more plant species and more plant cover than grazed pastures, (3) the vegetation pattern in the grazed pastures were unstable and increased degradation could be expected with continuing grazing pressure. In arid systems like the Central Anatolian, we expect that careful grazing management in long-disturbed range vegetation that is predominately Festuca valesiaca and Thymus sipyleus may be required to improve the vegetation community following natural successional patterns.

Technical Abstract: Because of increased grazing pressure over the last fifty years, vegetation of the steppe rangelands in the semi-arid Central Anatolian Region of Turkey has been severely degraded. In these pastures, Festuca valesiaca (a sod forming short-grass) and Thymus sipyleus ssp rosulans (a prostrate shrub) are now the dominant species. These two plant species are exceptionally grazing tolerant and may be considered indicators of rangeland degradation. If there are fewer dominant plant species due to excessive grazing, this might be associated with an altered vegetation composition. Therefore, our objectives were to investigate the effects of grazing on steppe vegetation by determining: (1) Whether there are patterns in the vegetation, (2) How dominant species contribute to the patterns, and (3) How does the pattern in grazed vegetation differ from the pattern in ungrazed vegetation. The study was conducted in rangelands near the Field Crops Central Research Institute Experimental Station, 45 km southwest of Ankara, in 2003. Three multi-scale vegetation plots were placed at each of the two grazing treatments (ungrazed and grazed). Protected areas possessed 14.3% more species, indicating that heavy grazing reduced species richness. Grazing changed composition through decreasing total plant (25.6% less), grass (33.5% less), and F. valesiaca cover (41.8% less) while it substantially increased T. sipyleus basal cover (56% more). In the flat area of grazed treatments F. valesiaca and in the flat pasture of ungrazed treatment T. sipyleus were more spatially homogenous in distribution. The vegetation patterns were explained by increasing abundances of F. valesiaca in ungrazed plots and T. sypileus in grazed plots. Three broad conclusions can be made: (1) F. valesiaca and T. sypileus had a significant effect in shaping of the vegetation pattern; (2) changes in species richness with increased covers of total plant, shrubs and G. orientalis was evident in comparing grazed and ungrazed pastures, (3) spatial heterogeneity of F. valesiaca and T. sypileus indicated unstable vegetative patterns in grazed pastures and successional changes in protected pastures. In arid systems like the Central Anatolian, we expect that careful grazing management in long-disturbed range vegetation that is predominately F. valesiaca and T. sipyleus may be required to improve the vegetation community following natural successional patterns.