ISSN:
1432-2285
Keywords:
Deciduous trees
;
Fagus sylvatica
;
Autumn leaves
;
Iron
;
Lead
;
Manganese
;
Zinc
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary By utilizing energy-dispersive X-ray microanalysis the heavy metals manganese, iron, zinc and lead were determined in different tissues of beech (Fagus sylvatica L.) autumn leaves. It was observed that all four metals were accumulated in sieve element-companion cell complexes of the leaf veins in the period from the green (2 October) to the brown (23 October) leaf coloration. Concomitantly, the concentration of these metals decreased in certain tissues of the stems subtending the leaves. The major reservoirs of heavy metals in the stems were periderm, cortex, pith and xylem rays. Since sieve element-companion cell complexes of the stems showed increasing metal concentrations during the transition from the green to the brown leaf stage, and since this temporary increase also occurred in the petiole phloem, it is inferred that symplastic transport can be used in addition to apoplastic transport for the displacement of heavy metals. It is assumed that the accumulation of heavy metals in the veins of autumn leaves indicates the deposition of surplus ions which are excluded when leaves are cast off.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00193559
