ISSN:
1573-5036
Keywords:
Ammonium
;
Eucalypt
;
Forest
;
Nitrate
;
Nitrate reductase
;
Nitrification
;
Pine
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary Three tree species,Eucalyptus regnans (F. Muell.),E. obliqua (L'Herit.),Pinus radiata (D. Don) were grown in sand culture with different proportions of nitrate and ammonium. Nitrate Reductase Activity (NRA) was induced in root tissue of all species and in leaf tissue of the eucalypts. An increasing proportion of nitrate resulted in increasing NRA in all species and hence NRA alone is no indication of N-preference. The highest NRA was found withE. regnans, a result which has also been obtained in the mature forest. The growth ofE. regnans was least with NH4 + alone, whereas that ofE. obliqua was least with NO3 − alone. The soils of matureE. regnans forest have a high potential for nitrification while those ofE. obliqua forest show little nitrification. Thus the preference for particular N sources shown by seedlings in culture is supported by related properties of mature forests. It is postulated however, that the inducibility of a high level of RNA in seedlings is more likely a result of a preference for NO3 − than a cause.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02183803
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