Effects of sylvicultural practices on nutrient status in a Pinus radiata plantation: Nutrient export by tree removal and nutrient dynamics in decomposing logging residues

Abstract

-The effects of logging residue management practices on export and dynamics of nutrients were studied in a plantation of Pinus radiata D. Don growing on an infertile soil, in a humid, temperate area of NW Spain. The export of nutrients due to the removal of wood and logging residues during thinning and clear-cutting was evaluated by estimation of nutrient stores in the above-ground biomass and in the soil. Nutrient dynamics in decomposing slash needles and twigs were monitored over one year in a thinned stand and in an adjacent clear-cut area. Comparison of nutrient release in decaying residues with the nutrient store in tree biomass as well as inputs via litterfall and atmosphere allowed discussion of possible implications for sustainable sylviculture in these plantations. Nutrient release from decomposing material increased following clear-cutting and to an even greater extent, after mechanical incorporation of logging residues to the mineral soil, which substantially increased the short-term flush of some nutrients. logging residues / decomposition / tree harvesting / thinning / forest nutrient cycling Résumé -Effets des pratiques forestières sur la nutrition d'un peuplement de Pinus radiata : exportation des éléments minéraux et dynamique des résidus en décomposition. Les effets de l'utilisation des résidus d'exploitations forestières sur l'exportation et la dynamique des éléments minéraux ont été étudiés dans une plantation de Pinus radiata D. Don située sur une station non fertile et dans une région humide et tempérée du Nord-Ouest de l'Espagne. Le flux d'éléments minéraux dû à l'exportation du bois et des résidus de l'exploitation forestière à la suite d'une éclaircie et d'une coupe rase a été évalué à partir de l'estimation des réserves d'éléments minéraux dans la biomasse aérienne forestière et dans le sol. La dynamique des éléments minéraux provenant des résidus en décomposition d'aiguilles et de brindilles a été suivi pendant un an dans une parcelle éclaircie et aussi dans une zone de déboisement adjacente. La comparaison de la libération d'éléments minéraux en décomposition avec la réserve d'éléments minéraux dans la biomasse des arbres, de même que les apports par les pluviolessivats et les pluies incidentes nous ont permis de discuter des implications possibles pour assurer la pérennité de la production forestière. La libération des éléments minéraux à partir de matières en décomposition augmente après le défrichement total, et ceci tout particulièrement après l'incorporation mécanique des résidus d'exploitations forestières au sol minéral, laquelle augmente de façon appréciable la libération d'éléments minéraux. résidus d'exploitation forestière / décomposition / récolte / éclaircissement / dynamique des éléments minéraux Ann. For. Sci. 58 (2001) [411][412][413][414][415][416][417][418][419][420][421][422] 411

A global meta‐analysis of soil exchangeable cations, pH, carbon, and nitrogen with afforestation

“…These soil losses are within the range of published values for total biomass Ca; for example, several Eucalyptus plantations in Australia had an estimated total biomass Ca of 0.32 Mg/ha and a Pinus radiata plantation in Spain was estimated at 0.33 Mg Ca/ha (Turner andLambert 1986, Ouro et al 2001). Additionally, the mean amount of soil magnesium lost due to afforestation with other conifers in this study was 0.27 Mg/ha, compared to an estimate of Pinus radiata magnesium stocks of 0.68 Mg/ha (Ouro et al 2001). The similarity in soil losses to total biomass content of Ca and Mg supports the hypothesis that uptake by plantations is a major driver of soil Ca and Mg loss (Richter et al 1994) and that plantation management leaving as much residue in place as possible will minimize problems of soil fertility in the future.…”

“…For instance, maintaining soil fertility could be accomplished through site and harvest management tools. Retention of logging slash, on site debarking and retention, and reduced burning of slash have been shown to reduce nutrient (Ca, Mg, N, and others) export, loss of soil organic material, erosion losses, and soil compaction (Merino and Edeso 1999, Bouillet et al 2000, Ouro et al 2001, Mendham et al 2003b, Merino et al 2004. Depending on initial site conditions, combinations of these different management conservation practices could improve sustainability.…”

Foliar N and P resorption and nutrient levels along an elevational gradient in Juniperus oxycedrus L. subsp. macrocarpa (Sibth. & Sm.) Ball

“…Proportional resorption was found by dividing the absolute resorption by the nutrient concentration in mature leaves. The proportional resorption is thus the proportion of nutrient concentration in a mature leaf that is removed from the leaf before it is shed [32,34,35,40,42]. Resorption estimation was not derived for K because it is easily leached from senescing leaves [44].…”

Response of plant functional traits during the restoration of calcareous grasslands from forest stands

“…Aerts (1995) reported the evergreen habit is primarily an adaptation to nutrient-poor environments. In the years following clear-cuts, litter decomposition may increase nutrient availability (Ouro et al 2001), and therefore be detrimental to evergreen species. Evidence of an increase in soil nutrient content was not detected by Piqueray et al (2011b) in the same study site.…”