Fjölrit RALA - 15.08.1980, Síða 38

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being put in the experiments to become overgrazed.
ólafur Guömundsson
Standing herbage
Figures on standing herbage in the pastures are presented in tables
60-108.
The measurements were made, as before, with a double sampling method
2
of ocular estimation and clipping. The R values of estimation vs
clipping were generally around 0.9 and the standard error of the estimated
pasture yields was generally on the order of 10%. The standing herbage
was measured three tiraes at most sites, at the beginning, in the middle
and at the end of the growing season. At Kelduhverfi and Eyvindardalur,
however, the final herbage measurements could not be made because of early
snowfall. All herbage was measured, also litter from the previous year.
The litter was a substantial proportion of the standing herbage at the
first measurement on some of the sites, especially on the bogs, but dropped
in most cases, very rapidly from then on. The litter proportion of the
yield was estimated but is not presented here.
Only herbaceous yield is presented here, except for the unfertilized
pastures at Auökuluheiöi and Hestur, where a small proportion of the
estimated yield consists of leaves of Betula nana and Salix species. At
Kelduhverfi the herbaceous yield in the unfertilized pastures is only a
small proportion of the total yield, which consists of a number of woody
species. ‘Annual growth of Betula nana, Vaccinium ulizinosum and Salix
species was also estimated but is not presented here.
Vegetation growth was very slow on most sites and the. experiments
started generally too early as compared to available yield. On some
sites this decreased the carrying capacity of the pastures considerably.
Andrés Arnalds