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Titolo:
Use of vector analysis to determine the effects of harvest residues on early growth of second-rotation Sitka spruce
Autore:
Proe, MF; Craig, J; Dutch, J; Griffiths, J;
Indirizzi:
Macaulay Land Use Res Inst, Plants Div, Aberdeen AB15 8QH, Scotland Macaulay Land Use Res Inst Aberdeen Scotland AB15 8QH AB15 8QH, Scotland Forestry Commiss Roslin, No Res Stn, Roslin EH25 9SY, Midlothian, ScotlandForestry Commiss Roslin Roslin Midlothian Scotland EH25 9SY ian, Scotland
Titolo Testata:
FOREST ECOLOGY AND MANAGEMENT
fascicolo: 1-2, volume: 122, anno: 1999,
pagine: 87 - 105
SICI:
0378-1127(19990913)122:1-2<87:UOVATD>2.0.ZU;2-T
Fonte:
ISI
Lingua:
ENG
Soggetto:
NORTHERN MIXED FOREST; PEATY GLEY SOILS; WHOLE-TREE; CONVENTIONAL HARVEST; SILVICULTURAL TREATMENTS; FOLIAR ANALYSIS; NITROGEN; PINE; STANDS; FERTILIZATION;
Keywords:
Sitka spruce; whole-tree harvesting; vector analyses; nutrient content; nutrient concentration; foliage biomass; sustainable forest management;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
57
Recensione:
Indirizzi per estratti:
Indirizzo: Proe, MF Macaulay Land Use Res Inst, Plants Div, Aberdeen AB15 8QH, Scotland Macaulay Land Use Res Inst Aberdeen Scotland AB15 8QH Scotland
Citazione:
M.F. Proe et al., "Use of vector analysis to determine the effects of harvest residues on early growth of second-rotation Sitka spruce", FOREST ECOL, 122(1-2), 1999, pp. 87-105

Abstract

Vector analyses have been used to examine the effects of harvest residues on the growth of Sitka spruce planted 18 months after clearfelling a first rotation of the same species. Four treatments were imposed at the time of planting: retention of all residues; retention of fine twigs and foliage; placement of coarse branch material onto plots; and removal of all harvest residues. Sample trees were harvested each year for five years after plantingand the biomass and nutrient contents of whole crowns were quantified. Harvest residues had a large effect on mean tree height (p < 0.001). Coarse and fine components produced similar increases when compared to plots with no residues although the response to fine material occurred earlier. After five years, residues had increased mean tree height by 40%. Residues alsoincreased the mean dry weight per tree although the response to coarse material was not significant until the age of five years, at which time trees in residues had 166% more biomass (p< 0.001). Tree growth was greatest where both forms of residue were retained on site. Interpretation of vector nomograms, foliage concentrations and concentration ratios indicated that the growth response was unlikely to he related to changes in nutrient supply for the first two years of treatment. Early treatment effects may have been mediated through changes in weed competition ormicroclimate. After three years, treatment effects were likely to have been related to altered nutrient supply, particularly those for nitrogen and potassium. According to vector analyses, potassium was not limiting tree growth in whole-tree harvested plots although foliage levels were below critical levels for young Sitka spruce and potassium : nitrogen ratios indicated a nutrient imbalance in these plots. Such an imbalance may arise from the rapid loss of potassium from decomposing harvest residues accompanied by a more gradual release of nitrogen that may relate more closely to the nutrient demand of newly planted trees. The contention that vector analyses allow a standardized comparison between treatments without confounding with other factors has to be questioned. In the present study, different interpretations resulted from analyses basedon comparing samples of different age-classes or from different canopy positions. The method has also been shown to be very sensitive to the choice of critical test statistic used in assessing each vector component. We conclude that vector analyses can provide a useful visualization of treatment effects on tree growth and nutrition, Its relevance to the assessment of sustainable forest management is limited by the need to have treatment comparisons available and interpretations should be corroborated by other evidence before firm conclusions can be drawn. (C) 1999 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 21/09/20 alle ore 11:51:44