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Aspect and Species Influences on Nitrogen and Phosphorus Availability in Arizona Chaparral Soils
Author(s) -
Klemmedson James O.,
Wienhold Brian J.
Publication year - 1991
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1991.03615995005500060038x
Subject(s) - chaparral , shrub , soil water , agronomy , environmental science , nutrient , litter , ecosystem , soil fertility , phosphorus , ecology , biology , chemistry , soil science , organic chemistry
Biota and topography are among the most important factors affecting nutrient status of wildland soils. Knowledge of these relations has a fundamental bearing on management of chaparral ecosystems. This study was conducted to determine the effect of shrub species and topographic aspect on availability of soil N and P in Arizona chaparral soils. Soil was collected under the canopy of 32 randomly selected shrubs, eight each of birchleaf mountain mahogany ( Cercocarpus betuloides Nutt.) and shrub live oak ( Quercus turbinella Greene) from both north and south aspects. A pot culture technique, using barley ( Hordeum vulgare L. var. gustoe ) and mountain mahogany ( C. montanus Torr.) as test plants, was used to estimate availability of soil N. and P. Both test plants showed that shrub species and aspect influenced nutrient availability. Availability of P was very low, while that of N was quite high. Lower availability of P in soils from southerly aspects was associated with low amounts of total soil P, probably the result of long‐standing differential erosion between north and south aspects, aggravated by fire. High N availability was probably associated with inputs of N via symbiosis between actinomycetes and mountain mahogany. Higher fertility of soils from oak systems is associated with lower lignin content of litter from these shrubs.