Changes in carbon allocation patterns in spruce and pine trees following irrigation and fertilization

Abstract

The paper presents an overview of the results of long-term fertilization and irrigation experiments in stands of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.). Large increases in stemwood production during the first 12 years of the experiments were achieved by fertilization especially when a balanced mixture of macro- and micronutrients was applied. The effect of irrigation alone was small, but it greatly enhanced the response of the ground vegetation to the application of a balanced fertilizer. Fertilization did not greatly affect the leaf/stemwood biomass ratio, but reduced the ratio of fine roots to total biomass. Drought reduced the coarse-root biomass/fine-root biomass ratio.

Spatial and temporal patterns of root distribution in developing stands of four woody crop species grown with drip irrigation and fertilization

“…Annual fertilizer treatments were split among 26 weekly applications between April and October. Split applications benefit tree growth and decrease N leaching and groundwater contamination compared with a single annual application (Axelsson and Axelsson 1986;Van Miegroet et al 1994). Fertilizer application supplied enough water to deliver liquid fertilizer and flush drip tubes (5 &week).…”

“…However, reported responses of root biomass and RLD to resource availability are inconsistent. The absolute amount of root biomass commonly increases in response to nutrients as plants increase in size (Fabiiio et al 1995;Persson 19801, but other studies show absolute declines in root quantity (Gower et al 1992) or relative declines compared to above ground tissues (Axelsson and Axelsson 1986). Forest growth process models commonly predict lower relative amounts of root tissue in response to high resource conditions (e.g.…”

Above- and below-ground biomass accumulation, production, and distribution of sweetgum and loblolly pine grown with irrigation and fertilization

“…Increased resource availability causes greater stem production, as a result of allocation to aboveground biomass components at the expense of roots (Linder 1989). This can be a desirable trait for productivity purposes and has been demonstrated in hardwoods (Barton and Montagu 2006) and conifers (Axelsson and Axelsson 1986;Albaugh et al 1998). However, it is important to compare trees at developmentally, not chronologically, similar stages (Reich 2002;Coyle and Coleman 2005).…”

Allocation of above-ground growth in Pinus sylvestris – impacts of tree size and competition

“…The needle growth can be estimated according to measurements of the youngest needle sets, but the branch growth is more complicated because it includes both radial and axial components. Branch growth has often been estimated at the stand level by comparing estimates of branch biomass in a crosssectional age series (Madgwick et al 1977, Linder and Axelsson 1982, Axelsson and Axelsson 1986, Kuuluvainen and Kanninen 1992, Nilsson and Gemmel 1993. Nilsson and Albrektson (1993) made an intensive study with 16-year-old trees in which branch growth was estimated as the difference between the biomass of shoot axes of consecutive whorls.…”