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Titolo:
FIELD AND LABORATORY EXPERIMENTS ON NET UPTAKE OF NITRATE AND AMMONIUM BY THE ROOTS OF SPRUCE (PICEA-ABIES) AND BEECH (FAGUS-SYLVATICA) TREES
Autore:
GESSLER A; SCHNEIDER S; VONSENGBUSCH D; WEBER P; HANEMANN U; HUBER C; ROTHE A; KREUTZER K; RENNENBERG H;
Indirizzi:
UNIV FREIBURG,INST FORSTBOT & BAUMPHYSIOL,AM FLUGHAFEN 17 D-79110 FREIBURG GERMANY UNIV FREIBURG,INST FORSTBOT & BAUMPHYSIOL D-79110 FREIBURG GERMANY UNIV MUNICH,LEHRSTUHL BODENKUNDE & STANDORTSLEHRE,FORSTWISSENSCHAFT FAK D-85354 FREISING GERMANY
Titolo Testata:
New phytologist
fascicolo: 2, volume: 138, anno: 1998,
pagine: 275 - 285
SICI:
0028-646X(1998)138:2<275:FALEON>2.0.ZU;2-4
Fonte:
ISI
Lingua:
ENG
Soggetto:
FREE AMINO-ACIDS; L KARST; ATMOSPHERIC AMMONIA; NITROGEN NUTRITION; NO3 UPTAKE; ASSIMILATION; INFLUX; BARLEY; PLANTS; INHIBITION;
Keywords:
NITRATE UPTAKE; AMMONIUM UPTAKE; SOIL TEMPERATURE; NITRATE TO AMMONIUM RATIO; AMINO ACIDS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
44
Recensione:
Indirizzi per estratti:
Citazione:
A. Gessler et al., "FIELD AND LABORATORY EXPERIMENTS ON NET UPTAKE OF NITRATE AND AMMONIUM BY THE ROOTS OF SPRUCE (PICEA-ABIES) AND BEECH (FAGUS-SYLVATICA) TREES", New phytologist, 138(2), 1998, pp. 275-285

Abstract

During the vegetation periods 1994 and 1995, net uptake of nitrate and ammonium by roots of adult spruce (Picea abies (L. ) Karst) and beech(Fagus sylvatica L.) trees was studied at a field site exposed to high loads of N ('Hoglwald', Germany). In addition, uptake experiments were carried out under controlled conditions with young spruce and beechtrees grown at normal N supply. In the field, nitrate was not taken up by the roots of spruce trees in appreciable amounts. This was also true for beech except during September 1995. Apparently, beech trees was capable of taking up nitrate, but the environmental condition prevailing at the field site usually prevented net uptake. Net uptake of ammonium in both tree species showed a seasonal course, with maximum rates in mid summer. Rates of ammonium uptake by both species correlated with soil temperature at the field site. Laboratory experiments on the influence of root temperature on uptake of nitrate indicated that uptake rates at temperatures found in the field were low compared with theuptake capacity at optimum temperature. At temperatures of 10 and 15 degrees C, frequently found in the soil at the field site, net uptake of nitrate by spruce and beech amounted to c. 16 % and 11 %, respectively, of maximum uptake at 25 degrees C. By contrast, net uptake of ammonium at 10 degrees C reached 73 % and 31 % of the maximum uptake for spruce and beech trees, respectively. Independent of temperature, rates of nitrate uptake were considerably lower than those of ammonium. Inyoung spruce and beech trees, net uptake of nitrate was significantlyinhibited by ammonium at nitrate:ammonium ratios found in the soil solution at the forest site. Preincubation of roots of both species, with amino acids present in the phloem of adult trees at the field site, led to an increase in the amino acid pool in the roots. For spruce trees a correlation between inhibition of uptake of nitrate and enrichment of the roots with the amino compounds Glu, gamma-amino butyric acid (Gaba), Gln, and Asn was observed. In beech trees, enrichment of Asp and Gln in the roots correlated with a decrease in net uptake of nitrate. The results of laboratory experiments on the effects of temperature, the nitrate to ammonium ratio in the nutrient solution, and amino acid enrichment in the roots are discussed with special emphasis on the patterns of net uptake of ammonium and nitrate observed in the field.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 10/07/20 alle ore 07:56:58