Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Doctorat → États-Unis → 1991 → Assessment of an integrated tebuthiuron-fire management system for pinyon-oneseed juniper woodlands in southcentral New Mexico

New Mexico State University (1991)

Assessment of an integrated tebuthiuron-fire management system for pinyon-oneseed juniper woodlands in southcentral New Mexico

Wittie Roger D

Titre : Assessment of an integrated tebuthiuron-fire management system for pinyon-oneseed juniper woodlands in southcentral New Mexico

Auteur : Wittie Roger D

Université de soutenance : New Mexico State University

Grade : Doctor of Philosophy (Ph. D.) 1991.

Résumé
An investigation regarding the influence of tebuthiuron (N- (5-01,1-dimethyethyl)-1,3,4-thiadizeol-2yl) -N,N-dimethylurea) and fire on a pinyon (Pinus edulis Engelm.) and oneseed juniper (Juniperus monosperma (Engelm.) Sarg.) woodland was conducted on the Ft. Stanton Experimental Ranch in Lincoln County, New Mexico, from 1983 to 1988. Age structure of pinyon and oneseed juniper within the study area consisted of relatively young and mature trees suggesting overstories represented reoccupying and/or invading stands. Non-suppressed trees grew rapidly and reached heights of 1.2 m or more within 20 years. Seedling height, stem diameter, basal area, and stem volume were highly correlated with tree age and were used to estimate stand replacement potential. Pinyon was more susceptible to tebuthiuron than was oneseed juniper. Mortality of both tree species was reduced when they grew beneath a sheltering canopy of another tree. Pinyon-oneseed juniper response to tebuthiuron varied by tree size, but the potential for selectively removing an individual size class declined as herbicide rate increased. Algerita (Berberis haematocarpa Woot.) and wavyleaf oak (Quercus undulata Torr.) exhibited similar susceptibility to tebuthiuron, but skunkbush sumac (Rhus trilobata Nutt.) was more tolerant. Spring burning was more effective for reducing seedling and mature pinyon-oneseed juniper cover in areas previously treated with tebuthiuron than in untreated woodlands. Cover reductions and resulting forage yields from tebuthiuron and burning treatments varied by site and were related to residual tree densities. Generally, germination of pinyon and oneseed juniper was enhanced following burning. The profitability of tebuthiuron-burning treatments was influenced by treatment cost, forage value, and discount rate. Generally, forage must be valued at greater than $9.00/AUM for treatment to be profitable. Treatment of high density stands with 1.4 kg/ha tebuthiuron, followed by burning, produced the greatest return on investment. Analyses also revealed pre-treatment stand density influenced profitability more than topo-edaphic strata.

Mots clés : Forest management — New Mexico. — Fire ecology — Pinyon pines

Présentation (WorldCat)

Search Oxford Libraries Online (SOLO)

Page publiée le 15 novembre 2013, mise à jour le 22 décembre 2019