The uptake of nutrients by mature forest growth

Abstract

Introduction.Definition of terms. The nutrient-uptake estimates calculated. The nature and validity of the original data. How the estimates were calculated. The validity of the estimates. The silvicultural significance of the mean estimates. Further aspects of the estimates, causes of variability and comparison with agriculture. The nutrient-uptakes in relation to nutrient-poor soils. Conclusions. Acknowledgements. Literature cited. ABSTRACTThe extremely low nutrient-status of various recently afforested moor soils, particularly Yorkshire (England) Calluna soils, raised the question of their ability to provide the possible nutrient-demands of continuous forest growth. This paper describes how, for calcium, potassium and phosphorus, uptake estimates have been calculated from existing nutrient-composition data, and discusses the silvicultural significance of such estimates, particularly in relation to nutrient-poor soils.All existing nutrient-composition data for whole individual mature temperate forest trees are summarized: using yield-data and a method of calculation critically discussed, they are made to provide nutrient-uptake estimates for one acre of such forest after periods of 50 and 100 years' growth. Mean estimates representing "hard~vood," "other conifer" and "pine" forest are then calculated showing : --the nutrients removed from the site via the various components of the timber-thinnings and clear-fellings, the --4 9 -- Plant and Soii VII PETER J. RENNIEnutrients taken up and immobilized within the various component organs of the growing forest, and the total nutrient-uptake from the site. The estimates show that timber exploited forest, by reason of its unavoidable continuous nutrient-removal from the site, differs fundamentally from unexploited virgin forest; in absolute terms this removal may be small, but its pedologicaI and silvicultural importance upon any particular site, depends entirely upor~ the ability of the soil to replenish this loss. It is believed that up to now the failure to recognize this nutrient-removal upon nutrient-poor soils has diverted attention from an important factor initiating both soil-degradation and diminishing site-productivity.Soil nutrient-data presented show that the nutrient-uptakes of timberproducing forest of either coniferous or hardwood species are so large compared with the nutrient-contents of moor soils that further overall soil-degradation and, sooner or later, diminished site-productivity are inevitable.Upon such soils, therefore, continuous timber production cannot be sustained by ploughing or by the growth of hardwoods alone; new silvicultural techniques are needed which can restore to the site, by means of suitable soil-ameliorants and methods yet to be evolved, the nutrients continually being removed via the timber.The paucity of knowledge concerning both the nutrient-demands of common tree species and the nutrient-status of the nutrient-poor soils upon which they are being extensively planted calls for an expansion of research upon these aspects if ti...

Characterizing base-cation immobilization in the stem of six hardwoods of eastern Canada

“…Processes by which nutrients are stored in trees and not returned to the soil until death, have not been the focus of attention. Limited research suggests interspecific differences in base-cation uptake and immobilization and direct influence on soil nutrient availability and fertility [8,24,31,34].…”

Modifying harvesting time as a tool to reduce nutrient export by timber extraction: a case study in planted teak (Tectona grandis L.f.) forests in Costa Rica

“…Nevertheless, the high amount of biomass accumulated in the tree stem makes it an important nutrient sink. As a consequence, the loss of nutrients through wood removal at harvesting is considered a major cause of nutrient impoverishment in forest sites (Rennie 1955, Fölster & Khanna 1997, Worrel & Hampson 1997. Our results show that the trunk nutrient concentration varies over the course of the year (Fig.…”

“…At the same time, forest managers are becoming increasingly concerned about the relationship between forest nutrition, soil management and sustainable timber production, with the challenge of maintaining high productivity rates over several rotations, especially in short-rotation plantations (Nambiar 1995, Fox 2000. Repeated nutrient export through timber harvesting over several rotations could cause soil nutrient depletion (Miller 1984, Fölster & Khanna 1997, Worrel & Hampson 1997, Merino et al 2005 and this may underlie the observed decrease in forest productivity over time (Rennie 1955, Evans 2009). This need to replace the nutrients lost (e.g., by fertilization) has traditionally been ignored by forest managers (Fölster & Khanna 1997), although FSC (2004 and other authors (Rennie 1955, Worrel & Hampson 1997, Merino et al 2005 recommend the application of fertilizer to sustain short-cycle plantation productivity.…”

“…Repeated nutrient export through timber harvesting over several rotations could cause soil nutrient depletion (Miller 1984, Fölster & Khanna 1997, Worrel & Hampson 1997, Merino et al 2005 and this may underlie the observed decrease in forest productivity over time (Rennie 1955, Evans 2009). This need to replace the nutrients lost (e.g., by fertilization) has traditionally been ignored by forest managers (Fölster & Khanna 1997), although FSC (2004 and other authors (Rennie 1955, Worrel & Hampson 1997, Merino et al 2005 recommend the application of fertilizer to sustain short-cycle plantation productivity. Although nutrient inputs (mainly wet and dry depositions and mineral weathering) may partially compensate for these nutrient extractions, this is usually not sufficient when the extraction is high and/or the rotations are short (Worrel & Hampson 1997).…”

“…In order to address the lack of sustainability and the possible decrease in long term production caused by nutrient depletion, authors of previous studies (Rennie 1955, Fölster & Khanna 1997, Ma et al 2007 have generally proposed the debarking of tree stems at the plantation site with the aim of minimizing nutrient export. However, this is considered an expensive, noncost effective and time-consuming practice by many forest managers and is currently not an option for forest companies in Central America.…”