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University of Arizona (1965)

A study of litter and vegetation in the upper chaparral area of central Arizona

Kemp, Kenneth

Titre : A study of litter and vegetation in the upper chaparral area of central Arizona

Auteur : Kemp, Kenneth

Université de soutenance : University of Arizona

Grade : Master of Science (MS) 1965

Résumé
A study of the chaparral species in central Arizona was conducted to obtain information pertaining to the organic matter associated with this vegetation type. Quercus turbinella Greene, shrub live oak, was the principal species involved in the study. Litter production from shrub live oak followed a seasonal pattern. The production pattern in decreasing order by season was as follows ; spring, simmer, fall, and winter. Litter yields were measured by two methods : (!) cages placed around shrub live oaks, and (2) litter baskets. Litter yields were mea sured on both north and south exposures by each of these two methods. South exposure cages yielded a mean weight of 1684 Ibs./acre/yr. for an acre covered entirely with shrub live oak or 786 Ibs./acre/yr. for an acre of land with the percent oak cover found at Sierra Ancha. North exposure cages yielded a mean weight of 1181 Ibs./acre/yr. for an acre covered entirely with shrub live oak or 611 Ibs./acre/yr. for an acre of land with the percent oak cover found at Sierra Ancha. Total litter yield from all species from litter baskets with no ad justment for bare areas was 1404 Ibs./acre/yr. on the south exposure and 1612 Ibs./acre/yr. on the north exposure. Litter yield for all species from litter baskets with bare areas accounted for was 1310 lbs./ acre/yr. from the south exposure and 1578 Ibs./acre/yr. for the north exposure. Litter baskets indicated unadjusted litter yields from shrub live oak to be nearly the same on both exposures, with south exposure yields being 1058 Ibs./acre/yr. and north exposure yields being 1099 Ibs./acre/yr. Adjusted for the percent oak cover measured on these two exposures, north exposure yielded 568 Ibs./acre/yr. and south ex posure yielded 482 Ibs./acre/yr. Within the ecto-humus horizon the L and F-subhorizons were found and measured on both exposures. No H-subhorizon was observed on either exposure. South exposure organic matter had a greater weight per unit thickness in all subhorizons. Shrub live oak was the principal species measured on bdth exposures, and the ground surface not covered by vege tation comprised approximately 20 percent of the total area of both exposures. The crown volume variable had the highest correlation coef ficients of all variables tested against weights of litter yield.

Mots clés : Chaparral ecology. ; Litter (Trash) — Arizona.

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Page publiée le 26 janvier 2016, mise à jour le 13 décembre 2017