Performance of two Picea abies (L.) Karst. stands at different stages of decline

Abstract

This is the first in a series of papers on the growth, photosynthetic rate, water and nutrient relations, root distribution and mycorrhizal frequency of two Norway spruce forests at different stages of decline. One of the stands was composed of green trees only while the other included trees ranging in appearance from full green crowns to thin crowns with yellow needles. In this paper we compare the growth and carbohydrate relations of the two stands and examine relationships among growth variables in ten plots. The declining stand produced 65 percent of the wood per ground area compared with the stand in which all trees were green because its foliage produced less wood at any level of leaf area index. The difference in foliage efficiency between the sites could not be explained by differeneces in climate, competition or stand structure. The declining stand appeared to have lower carbon gain as indicated by a smaller increase in reserve carbohydrates before bud break, and weaker sinks for carbohydrates as indicated by less use of the stored carbohydrates than the healthy stand. Thus, growth reduction was probably related to factors which affect both photosynthesis and, even more, the sinks for carbohydrate.

Fine root dynamics in a Norway spruce forest (Picea abies (L.) Karst) in eastern Sweden

“…The root function is costly and is enhanced by a high carbohydrate supply (Ågren et al 1980;Ericsson and Persson 1980;Hallgren et al 1991;Johansson 1993;Kobe 1997;Langley et al 2002;Lippu 1998;Marshall and Waring 1985;Oren et al 1988). High starch reserves are accumulated in tree roots, supporting a high turnover rate (Ericsson and Persson 1980).…”

Effects of biogeochemical processes on magnesium isotope variations in a forested catchment in the Vosges Mountains (France)

“…The decrease of needle Mg content with age is well known and appears during each new cycle of needle synthesis. Oren et al (1988) highlight that for synthesis of new needles in spring, Mg comes from two sources:…”

Novel mannose‐sequestration technique reveals variation in subcellular orthophosphate pools do not explain the effects of phosphorus nutrition on photosynthesis in Eucalyptus globulus seedlings

“…Starch and soluble sugars were determined colorimetrically with anthrone according to the methods of Hansen & Mφller (1975), Marshall (1986) and Oren et al (1988) and then quantified at an absorbance of 630 nm using a UV-Vis Spectrophotometer. Standard curves over 0-1 mg ml -1 were linear (r 2 > 0.998).…”