DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 3-4/1999 str. 18 <-- 18 --> PDF |
N. I´crnar. D. Bakšić, Ž. Spanjol: NEKE ZNAČAJKE HUMIZACIJE U BOROVIM KULTURAMA NA OTOKU RABU Šumarski list br. 3 4, CXXII1 (1999), 101-108 222.7g kg ´. Significant differences in the participation of inert, transformation- resistant organic soil matter were revealed. These facts correspond well to humus content and to the relation between humic andfulvic acids. The ratio ofhumic and fulvic acids in the plantation of maritime pine on eutric brown soil is particularly prominent, and reaches 2.7, while its average in the plantations of Aleppo pine on brown soil on calcareous breccias is 0.9, and on brown soil on lime stone 0.7. Preliminary analyses of samples from the O-horizon have shown relatively low, and sometimes even negative correlative links between nitrogen content in O-subhorizons and the A-horizon, which denotes very complex relations in the transformation model of organic matter in these ecosystems. With regard to qualitative and quantitative characteristics of humus in the studied stands, a question arises of the causes of their differences, as well as of their consequences for the stability of the ecosystem. The following can be said: 1. Since this is an ecosystem with a meliorative role, these differences are an indication of different meliorative effects in given circumstances (the stands are differently aged, consist of different species and occur in different site conditions). 2. Humization is a basic pedogenetic process characterised by a dynamic balanced condition in the matter cycle of the ecosystem. The research has shown that there are different trends in humization owing to the influence of both plant species and the parent substrate. 3. Research should be carried out on a more representative sample. 4. Bearing in mind the role and importance of pine cultures in the ecosystems of eu-Mediterranean and sub-Mediterranean regions in Croatia, we believe that criteria should be drawn up for the assessment of the effects of these cultures in relation to pedological indicators and ecosystem development trends. |