ISSN:
1573-5052
Schlagwort(e):
Ammonium toxicity
;
Arnica montana
;
Calluna vulgaris
;
Cirsium dissectum
;
Nitrogen
;
Soil acidification
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
Notizen:
Abstract Arnica montana and Cirsium dissectum, typical of species-rich heathlands and acidic grasslands, have declined rapidly in The Netherlands in recent years. Field surveys suggest that the decline is caused by soil acidification as a result of enhanced atmospheric N and S deposition. Therefore, the survival, growth and development of these species were studied in a water culture experiment, using nutrient solutions which differed both in mineral nitrogen form and in ammonium concentration. For comparison, the performance of a third, acid tolerant species, Calluna vulgaris, was studied. The results showed that both Arnica and Cirsium performed better using nitrate than when using ammonium as a sole nitrogen source, whereas ammonium toxicity became apparent when ammonium concentrations were raised above 100 µM. Ammonium toxicity was expressed by an increase in mortality of Arnica plants with increasing ammonium concentrations and by a reduction of biomass in Arnica and Cirsium. Furthermore, cation concentrations in both roots and shoots decreased when ammonium was supplied as a nitrogen source. In contrast, Calluna showed optimal development when using ammonium as a sole nitrogen source. In this species, only root biomass was negatively affected by high ammonium concentrations. The ecological implications of these preferences are discussed in relation to soil acidification.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1023/A:1009717613380
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