Title: Effect of utilization on biomass and vegetation in Mongolian rangeland

Type:
Final project
Year of publication:
2012
Document URL: Link
Supervisors: Ásrún Elmarsdóttir
Keywords:
rangeland, degradation level, cutting frequency, cutting height, resting impact

Abstract

The rangeland in the mountain forest steppe in Mongolia has degraded for the last decades, mainly because of overgrazing. This has challenged the government to improve the land and gather information about the tolerance of the rangeland. Livestock production is an important part of the economy and is based on the natural rangeland. The aim of this
research was to test the effect of cutting frequency (four, three, two and one), cutting height (0 and 3 cm) and duration of cutting on aboveground biomass and also to test the effect of grazing exclusion on vegetation cover at different degradation levels of Fescueforbs rangeland. Three sites were selected with different degradation levels; slightly, moderately and heavily degraded. The cutting experiment was a randomized complete block design with five replications. Sampling was carried out in 2006, 2007 and 2008. In 2009 all the plots were cut at the same time in August and at 0 cm height and the results were analysed. The results showed that total biomass was influenced by cutting frequency, cutting height and duration of cutting. The biomass decreased considerably with increasing cutting frequency, in most cases when cutting height was 0 cm, but small changes were noticed when the cutting height was 3 cm. The biomass decreased by 30-54% when cut four times per year at 0 cm in slightly and moderately degraded sites. Years of duration influenced biomass significantly at slightly and heavily degraded sites. The total vegetation cover was higher in ungrazed sites compared with grazed sites within all three degradation levels. Grasses and forbs had improved on ungrazed slightly and heavily degraded sites. This study showed that the intensity of grazing readily influences biomass production but also that recovery of rangeland can be slow when weather conditions are unfavourable.

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