Individual-tree diameter growth models for quantifying within-stand response to nitrogen fertilization

Shafii, Bahman; Moore, James A.; Newberry, James D.

doi:10.1139/x90-153

Cited by 20 publications

(7 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The magnitude of fertilization responses was 33% to 97% for PAI of basal area and 25% to 92% for PAI of volume over the 20 years following treatment. This magnitude is comparable to the previous true fir studies (Heninger 1982;Miles and Powers 1988;Shafii et al 1990;Weetman et al 1976) and to averages for other sympatric forest species (Miles and Powers 1988;Weetman et al 1976). Based on results from only a few test plots that were measured for less than 10 years, Powers (1981) concluded that urea fertilization could improve height growth by 30% to 80%.…”

Section: Effect Of Treatment Interactionsupporting

confidence: 88%

“…Mortality was negligible in both fertilized and nonfertilized heavily thinned plots. Fertilizer-enhanced mortality was not found in a study of grand fir (Shafii et al 1990). …”

Section: Thinning Effectmentioning

confidence: 91%

“…Shafii et al (1990) emphasized tree size and fertilization interactions to demonstrate merchantable volume response and the associated economic returns. However, Powers (1992) showed that on average, 5-year volume growth doubled for trees with a QMD <15 cm, increased 30% for 15-25 cm QMD trees and 10% for 25-35 cm QMD trees, and declined by 9% for >35 cm QMD trees.…”

Section: Fertilization By Thinning Interactionsmentioning

confidence: 99%

“…ex D. Don) Lindl.) suggests that the effect of fertilization with 224 kg N/ha was marginal and nonsignificant (Shafii et al 1990), unless thinning was combined with fertilization. The effect of fertilization on growth has also been reported for balsam fir (Abies balsamea (L.) Mill.)…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Long-term effects of thinning and fertilization on growth of red fir in northeastern California

Zhang¹,

Oliver²,

Powers³

2005

Can. J. For. Res.

View full text Add to dashboard Cite

To determine the impact of fertilization and thinning on growth and development of red fir (Abies magnifica A. Murr.) stands, we established an experiment in a 60-year-old stand using a 2 × 3 factorial design with nitrogen-fertilized and nonfertilized treatments and three stocking levels. Plots were established in 1976 and were measured every 5 years for 26 years. The periodic annual increment in basal area was 97%, 51%, 38%, and 33% greater in fertilized trees than in nonfertilized trees during the first, second, third, and fourth 5-year periods, respectively. After 20 years, annual basal area increment was greater in nonfertilized trees. The response of annual volume increment to fertilization was not statistically significant until the fourth period. Yet, volume increases of the fertilized plots were 25%-92% greater than those of the nonfertilized plots from 1976 to 1996. Similarly, basal area increment was greater in lightly thinned plots than in unthinned plots from the second period on, until heavy mortality during 1996-2002. Basal area increment was greater in the heavily thinned plots from the fourth period on. Results indicate that red fir can respond to fertilization and thinning quickly and that both treatments speed stand development. In addition, fertilization increases the stand's carrying capacity. Therefore, forest managers can use these silvicultural practices to improve stand growth, to reduce fire fuels, and to accelerate stand development. Résumé :Pour déterminer l'impact de la fertilisation et de l'éclaircie sur la croissance et le développement de peuplements de sapin rouge (Abies magnifica A. Murr.), nous avons établi, dans un peuplement de 60 ans, un dispositif expé-rimental de type factoriel 2 × 3 avec présence et absence de fertilisation et trois niveaux de densité. Les placettes ont été établies en 1976, puis mesurées à tous les 5 ans pendant 26 ans. Les arbres fertilisés ont eu un accroissement annuel périodique en surface terrière de 97, 51, 38 et 33 % supérieur à celui des arbres non fertilisés après les première, deuxième, troisième et quatrième périodes de 5 ans, respectivement. Après la quatrième période de 5 ans, les arbres non fertilisés ont eu une meilleure croissance annuelle en surface terrière. La réaction de l'accroissement annuel en volume à la fertilisation n'a pas été statistiquement significative avant la quatrième période de 5 ans. Malgré tout, les placettes fertilisées ont eu un accroissement en volume de 25 à 92 % supérieur à celui des placettes non fertilisées entre 1976 et 1996. De la même façon, les placettes légèrement éclaircies ont eu un accroissement en surface terrière supé-rieur à celui des placettes non éclaircies à partir de la deuxième période de 5 ans jusqu'à un épisode de mortalité intense survenu entre 1996 et 2002. Les placettes fortement éclaircies ont montré un accroissement en surface terrière supérieur à partir de la quatrième période de cinq ans. Les résultats indiquent que la réaction du sapin rouge à la fertilisation et à l'éclaircie est rapide...

show abstract

Section: Effect Of Treatment Interactionsupporting

confidence: 88%

“…Mortality was negligible in both fertilized and nonfertilized heavily thinned plots. Fertilizer-enhanced mortality was not found in a study of grand fir (Shafii et al 1990). …”

Section: Thinning Effectmentioning

confidence: 91%

Section: Fertilization By Thinning Interactionsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Long-term effects of thinning and fertilization on growth of red fir in northeastern California

Zhang¹,

Oliver²,

Powers³

2005

Can. J. For. Res.

View full text Add to dashboard Cite

show abstract

“…Thus, there is a continuing need to model growth response to fertilization at the tree level. Such an example was provided by Shafii et al (1990), Stage et al (1990), and Hynynen (1993). However, there are no published individual tree basal area growth models that relate fertilization response to habitat type, rock type, stand attributes, and tree attributes and that are compatible with growth simulation models used in the region (Wykoff et al 1982).…”

Section: Introductionmentioning

confidence: 99%

The effect of habitat type and rock type on individual tree basal area growth response to nitrogen fertilization

Shen¹,

Moore²,

Hatch³

2000

Can. J. For. Res.

View full text Add to dashboard Cite

Individual tree basal area increment models for nitrogen fertilized stands were developed using data from permanent research plots located throughout the Inland Northwest. Results show that tree size, stand density, habitat type, and rock type significantly interact to affect individual tree basal area growth response to nitrogen fertilization. Suppressed trees growing on moist habitat types and all rock types, except metasedimentary, exhibited greater relative response than did dominant or codominant trees growing in the same stand. However, suppressed trees growing on dry sites or on soils derived from granite rocks did not show different relative response than dominant or codominant trees growing in the same stand. This study quantitatively demonstrates that individual tree competitive relationships are significantly affected by rock type. Rock types proved to be useful in representing broad differences in a site's nutrient environment. Incorporating the new equations into individual tree growth and yield simulators would provide better representation of N fertilization response differences within a stand.Résumé : Des modèles d'accroissement en surface terrière d'arbres individuels dans des peuplements soumis à une fertilisation azotée ont été développés à l'aide de données provenant de parcelles expérimentales permanentes situées un peu partout à l'intérieur des terres dans le Nord-Ouest. Les résultats montrent que la dimension des arbres, la densité du peuplement, le type d'habitat et le type de roche interagissent de façon significative pour affecter la croissance en surface terrière d'arbres individuels en réponse à la fertilisation. Les arbres supprimés qui croissent sur des types d'habitat humide et tous les types de roche, à l'exception du type méta-sédimentaire, montrent une réponse relative plus forte que celle des arbres dominants et co-dominants qui croissent dans le même peuplement. Cependant, les arbres supprimés qui croissent sur des sites secs et sur des sols dérivés de roches granitiques n'ont pas montré de ré-ponse relative différente de celle des arbres dominants ou co-dominants qui croissent dans le même peuplement. Cette étude quantitative démontre que les relations de compétition entre arbres individuels sont affectées de façon significative par le type de roche. Les types de roche s'avèrent utiles pour représenter de fortes différences dans l'environnement nutritif d'un site. L'introduction de nouvelles équations dans les modèles de croissance et de rendement d'arbres individuels permettrait d'avoir une meilleure représentation des différences de réaction à la fertilisation azotée dans un peuplement.[Traduit par la Rédaction] Shen et al. 623

show abstract

Bibliography

2011

Forest Growth and Yield Modeling

View full text Add to dashboard Cite

Individual-tree diameter growth models for quantifying within-stand response to nitrogen fertilization

Cited by 20 publications

References 7 publications

Long-term effects of thinning and fertilization on growth of red fir in northeastern California

Long-term effects of thinning and fertilization on growth of red fir in northeastern California

The effect of habitat type and rock type on individual tree basal area growth response to nitrogen fertilization

Bibliography

Contact Info

Product

Resources

About