ISSN:
1573-2932
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
Notes:
Abstract Nutrient cations are removed from the soil by uptake in biomass, and by leaching as a result of soil acidification. Such acidification results from acid deposition and/or from HNO3 formed by mineralization and nitrification of humus, when at a rate in excess of the tree's nutritional requirements. This has been found to occur during and follwing periods of increased temperature and reduced rainfall. The cumulative loss of either Ca2+, Mg2+ or K+ by one or more of these processes, if greater than the amount released from the specific minerals in that soil, leads to nutrient deficiency, fine root mortality, poor growth, and eventually to die-back. Trees growing in soils derived from specific minerals in which there is a strong imbalance in the elements from which the exchangeable nutrients are formed, are vulnerable to nutrient deficiency. This paper discusses the relevance of earlier studies, when considered in relation to more recent findings. In Hawaii there have been frequent periods of increased temperature and drought resulting from the El Niño Southern Oscillation. This fact, when considered in relation to the relatively low K content, and its imbalance with Ca and Mg in the lava and volcanic ash on which the trees have grown, could result in K deficiency in the declining ohia trees. It is possible that the unusual periods of increased temperature and drought which have occurred in certain other localized areas may have led to the decline symptoms recently observed. In view of the threat of global warming, this possibility should be investigated.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00479856
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