. Chasse et pêche de la Californie. Pêche -- Californie ; jeu et jeu-oiseaux -- Californie ; Poissons -- Californie ; groupes de population animale ; pêches ; gibier, poissons. Effets de l'ÉLIMINATION DE LA VÉGÉTATION 217 jicrcent percoiit, tuer 50 ; (5  % pin lier, tuer 50 pour cent. En outre, deux petites vignes, deux petits chênes vivent de l'intérieur, et deux buck- plantes brosse tous près de la source ont été coupées à la main. hy Circulation de l'printemps a augmenté après la Gravure et découpe pour trois ou quatre da,vs mais alors la tendance à la baisse s'est poursuivie à un taux égal à celui avant le traitement (Figure 6). Le résultat net est que le débit wa

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. California fish and game. Fisheries -- California; Game and game-birds -- California; Fishes -- California; Animal Population Groups; Pêches; Gibier; Poissons. EFFECTS OF VEGETATION REMOVAL 217 percoiit, kill 50 jicrcent; (lier pine 5 percent, kill 50 percent. In addi- tion, two small grapevines, two small interior live oaks, and two buck- brush plants all near the spring were cut hy hand. Flow of the spring increased after burning and cutting for three or four da, vs but then the trend continued downward at a rate equal to that before treatment (Figure 6). The net result was that the flow was set ahead about 15 days.. 10 15 20 JULY S 10 IS SCPTEIMBCR FIGURE 6. Flow of Pipe Spring before and after control-burn on August 5, 1950. Rock Spring This watershed Avas one of five acres. It was control-burned on July 22, 1950. The crown cover of shrubs and trees was estimated to be 65 percent. The species composition and degree of top-kill were as fol- lows: whitethorn chaparral 50 percent, kill 85 percent; buckbrush 15 percent, kill So percent; digger pine 10 percent, kill 85 percent; in- terior live oak 15 percent, kill 90 percent; manzanita 3 percent, kill 95 percent; blue oak 2 percent, kill 75 percent; buckeye 3 percent, kill 90 percent; redberry 2 percent, kill 90 percent. The spring water comes from a crack down about 10 feet in solid rock. Several years ago the spring furnished water year-long for a homesteader. However, the ranch owner reported that in recent years it had gone dry each sinnmer. Before the control burn the spring decreased rapidly in flow and, although the control burn produced an excellent top-kill, no change in trend of flow was found. Apparently the deep-rooted trees and shrubs had already depleted the water at this time (Figure 7). This spring was measured several times in lf)51 between September 12 and October 24, at the time of the first fall rain ; also on August 8, 1952, August 30, 1955, and August 13, 1957. The flow data per day are shown