Ammonium and nitrate in the nitrogen economy of some conifers growing in Douglas-fir communities of the Pacific North-West of America

Krajina, Vladimir J.; Madoc-Jones, Sarah; Mellor, G. E.

doi:10.1016/0038-0717(73)90100-4

Cited by 73 publications

(38 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The 33 locations analyzed included 20 urban forest sites (11 edge and 9 center) and 13 rural forest sites (7 edge and 6 center). While both NO 3 − and ammonium (NH 4 + ) are available to plants in soil, only nitrate levels were measured because soil nitrate appears to be more important than ammonium to conifer species in our region (Krajina et al 1973), and because similar effects or patterns between nitrate levels and ammonium levels would be expected (Lovett et al 2000).…”

Section: Experimental Designmentioning

confidence: 99%

Conifer growth and reproduction in urban forest fragments: Predictors of future responses to global change?

2012

View full text Add to dashboard Cite

Global change has a large and growing influence on forests, particularly in urban and urbanizing areas. Compared to rural forests, urban forests may experience warmer temperatures, higher CO 2 levels, and greater nitrogen deposition, with exacerbated differences at urban forest edges. Thus, comparing urban to rural forests may help predict future effects of global change on forests. We focused on the conifer western red-cedar (Thuja plicata) to test three hypotheses: at urban forest edges, relative to rural forests and urban forest centers, trees experience 1) higher temperatures and nitrogen levels, 2) lower seedling recruitment, and 3) greater growth. We additionally tested anecdotal reports that 4) tree seedling recruitment in urban and rural forests is much lower than in "pristine" old-growth forests. To test these hypotheses, we quantified air temperature, soil nitrate, adult T. plicata growth and seedling recruitment in five urban and three rural parks at both forest edges and centers. We also quantified T. plicata recruitment at five old-growth "pristine" sites. Temperatures were highest at urban forest edges, and soil nitrate was highest in urban forests. In urban relative to rural forests, we observed greater T. plicata growth, but no difference in seedling densities. However, seedling densities were lower in urban and rural forests than in old-growth forests. In all, our results suggest urban influences enhance adult T. plicata growth, but not seedling recruitment. Recruitment in urban and rural forests was reduced compared to old-growth forests, implying that fragmentation and logging reduce T. plicata seedling recruitment.

show abstract

Section: Experimental Designmentioning

confidence: 99%

Conifer growth and reproduction in urban forest fragments: Predictors of future responses to global change?

2012

View full text Add to dashboard Cite

show abstract

“…), but not western red cedar, responded with increased growth relative to control seedlings. Messier [22] On the basis of studies of seedlings grown in sandy soils, Krajina et al [21] and Gijsman [13] have suggested that western red cedar and Douglas fir prefer NO 3 --N rather than NH 4 + -N. In contrast, greater dry matter production with NH 4 + -N [21,34] has been reported for western hemlock [21,34] and Douglas fir [3] [5].…”

mentioning

confidence: 99%

“…At the two sites, the soils were pushed through a large-framed 4- [21] (20 mesh), and subjected to modified Kjeldahl digestion [6] to allow determination of their N concentrations.…”

mentioning

confidence: 99%

Dry matter and nitrogen allocation in western redcedar, western hemlock, and Douglas fir seedlings grown in low- and high-N soils

Hermann

Zaerr

1999

Ann. For. Sci.

View full text Add to dashboard Cite

“…Na verdade, certas espécies preferem a forma amoniacal (Griffith & Streeter, 1994). É interessante ressaltar que, na preferência à forma amoniacal, têm-se observado diferenças entre cultivares de uma mesma espécie (Krajina et al, 1973). Nesse sentido, espécies ou cultivares de plantas que crescem bem em solos ácidos, com reduzida nitrificação, tendem a preferir a forma amoniacal à nítrica (Kirkby, 1968).…”

Section: Resultsunclassified

Cultivo do feijoeiro em solução nutritiva sob proporções variáveis de amônio e nitrato

Vale

Guazelli

Neto

et al. 1998

Rev. Bras. Ciênc. Solo

View full text Add to dashboard Cite

O experimento foi desenvolvido em solução nutritiva, em condições de casa de vegetação do Departamento de Ciência do Solo da Universidade Federal de Lavras, e teve, como objetivo, avaliar a influência de diferentes proporções de NH4+:NO3- sobre o crescimento, nutrição e eficiência de utilização de nitrogênio na fase inicial de crescimento de três cultivares de feijoeiro (Phaseolus vulgaris L.) Rio Tibagi, Eriparsa e Carioca. Mediu-se a resposta a 4 mmol L-1 de nitrogênio, suprido nas proporções de NH4+:NO3- de 0:4, 1:3, 2:2, 3:1 e 4:0, por meio da matéria seca de raiz e parte aérea, bem como os teores de P, S, Ca, Mg, K e a avaliação da eficiência de utilização de nitrogênio. Os cultivares de feijoeiro foram afetados pela relação NH4+:NO3-. A maior produção de matéria seca foi verificada com o suprimento de amônio e nitrato, em igual proporção. Com o predomínio de nitrato, os cultivares Carioca e Rio Tibagi mostraram maior e menor eficiência de utilização de N, respectivamente. O suprimento exclusivo de amônio, para os cultivares de feijoeiro estudados, resultou em sérios prejuízos ao sistema radicular, com conseqüente redução na absorção de nutrientes, notadamente de cálcio.

show abstract

Ammonium and nitrate in the nitrogen economy of some conifers growing in Douglas-fir communities of the Pacific North-West of America

Cited by 73 publications

References 3 publications

Conifer growth and reproduction in urban forest fragments: Predictors of future responses to global change?

Conifer growth and reproduction in urban forest fragments: Predictors of future responses to global change?

Dry matter and nitrogen allocation in western redcedar, western hemlock, and Douglas fir seedlings grown in low- and high-N soils

Cultivo do feijoeiro em solução nutritiva sob proporções variáveis de amônio e nitrato

Contact Info

Product

Resources

About