University of California

Litter and forest floor of the chaparral in parts of the San Dimas Experimental Forest, California


Joseph Kittredge

Author Affiliations

Joseph Kittredge was Professor of Forestry and Forest Ecologist in the Experiment Station, Emeritus, Berkeley.

Publication Information

Hilgardia 23(13):563-596. DOI:10.3733/hilg.v23n13p563. May 1955.

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The Chaparral is the shrubby, mostly evergreen vegetation on the mountains of southern California. This type of vegetation is influential in securing favorable conditions of water flows—an important factor in the justification of national forests in that part of the state. One of the ways in which the chaparral exerts its influence is through the deposition and accumulation of leaf litter and other organic material on the surface of the ground. The term “litter” will be used herein to denote the annual accumulation, and the term “forest floor,” the total organic matter above the surface of the mineral soil at any time, including fresh litter and decomposed older materials. The purpose of this study was to obtain quantitative data on the annual rates of accumulation and decomposition of different types, ages, and densities of chaparral, and the amounts, volume weights, and field moisture capacities of forest floor. Such data constitute a small part of the information needed as a basis for improving the effectiveness of the chaparral as a watershed cover by something corresponding to silvicultural treatment. The rest of the information is being obtained by the members of the California Forest and Range Experiment Station assigned to the Experimental Forest (13).3

Previous Work

The results of records made during the first three years of this project were reported in 1939 (7), (8). Recently detected errors in computations in those reports have been corrected wherever the figures are used in this paper. Data from that period needed for comparisons or the establishment of trends will be reproduced at appropriate points. A review of the literature through 1947 has been made previously (9). At North Fork, California, the annual accumulation for four years was unusually high. On a 1/200-acre plot of wedgeleaf ceanothus (Ceanothus cuneatus) and Mariposa manzanita

Literature Cited

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[7] Kittredge J. Jr. The annual accumulation and creep of litter and other surface materials in the chaparral of the San Gabriel mountains, California. Jour. Agr. Res. 1939. 58:537-41.

[8] Kittredge J. Jr. The forest floor of the chaparral in San Gabriel mountains, California. Jour. Agr. Res. 1939. 58:521-35.

[9] Kittredge J. Jr. Forest influences. 1948. N.Y.: McGraw-Hill Book Co. 394p.

[10] Rowe P. B. Influence of woodland chaparral on water and soil in central California. 1948. U. S. Forest Service and California Div. of Forestry. 70p.

[11] Rowe P. B. Effects of the forest floor in disposition of rainfall in pine stands. Jour. Forestry 1955. (in press)

[12] Shaw C. R. The normal moisture capacity of soils. Soil Sci. 1927. 23:303-17. DOI: 10.1097/00010694-192704000-00004 [CrossRef]

[13] Sinclair J. D., Hamilton E. L. A guide to the San Dimas Experimental Forest. 1953. IT. S. Forest Service, California Forest and Range Exp. Sta. 17p. Misc. Paper No. 11

[14] Tarrant R. F., Isaac L. A., Chandler R. F. Observations on litter fall and foliage nutrient content of some Pacific Northwest tree species. Jour. Forestry. 1951. 49:914-15.

[15] U. S. Forest Service. Some aspects of watershed management in southern California. 1951. California Forest and Range Exp. Sta. 29p. Misc. Paper No. 1

[16] U. S. Forest Service. Annual report. Rocky Mountain Forest and Range Exp. Sta. 1951. 1951:29-31.

[17] Wilm H. G., Nelson A. Z., Storey H. C. An analysis of precipitation measurements on mountain watersheds. Monthly Weather Rev. 1939. 67:163-72. DOI: 10.1175/1520-0493(1939)67<163:AAOPMOreplacecodegt2.0.CO;2 [CrossRef]

Kittredge J. 1955. Litter and forest floor of the chaparral in parts of the San Dimas Experimental Forest, California. Hilgardia 23(13):563-596. DOI:10.3733/hilg.v23n13p563
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