Nutrient and water uptake by roots of forest trees

Abstract

Summary -ZusammenfassungAlthough per growing season nutrient uptake of adequately growing forest trecs is less than the nuuient uptake of annual crop zpecies. nutrient uptake per unit mot length in trees is Considerable. Becauze of high heterogeneity of soil conditions and root p w t h in forest soils, modelling of uptake processes is even more dificult for forest than for crop stands. Detailed studies bhow chat whitc tips of growing tree m t s have a high nument uptake capacity. However. most mot tips are u%ually colonised by mycorrhizal fungi. These fungi can participate whbtanljally in ~e e nuuient uptake. in panicular in the utilisation ot organically-bound phosphorus und nitrogen in soils. Mycorrhizal hyphae. root tips. and older root zones can all absorb water, but their actual contribution IS difficult to assess. In this review. experimental results from our laboratory and literarure data are used to describe the potential activity of tree roofs and rnycorrhizas in nutrient and wakr uptake. Methodology for in siru measurements must be developed to quantify at different forest sites the actual contribution of mycorrhizas and different root parts.

Interspecific competition impacts on the morphology and distribution of fine roots in European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) Karst.)

“…The conservative strategy of spruce of keeping its shallow vertical fine root distribution patterns and morphology in both pure and mixed stands contrasts with the flexible 'foraging' strategy of mixed beech which shifts fine roots from upper to lower soil layers and increases SRL, SSA and thereby soil exploitation efficiency (Bauhus et al 2000;Grams et al 2002). This points to a complementary exploitation of soil resources in mixed spruce-beech stands compared to pure spruce stands if the spatial rooting and resource uptake patterns coincide, which is, however, not always the case (George and Marschner 1996). Positive tree nutrition effects in the mixed stand facilitated by nutrient uptake of the shallowrooting spruce in the upper soil, and the deeper rooting beech in the lower subsoil ('nutrient pump effect', Rothe and Binkley 2001) cannot be expected at our sites since no nutrient-rich subsoil layers could be reached by the roots.…”

Macronutrients in tree stems and foliage: a comparative study of six temperate forest species planted at the same sites

“…For a given species at a particular site, the methods of soil analysis give only approximate estimates of actual nutrient availability, which depends on many factors such as soil moisture [8,17] or mycorrhizal association [21]. The absence of good correlations between nutrient concentrations in the soil and in plant biomass for the majority of nutrient elements is also a strong indication of species' ability to keep nutrient concentrations in the biomass within a certain range, even on less fertile soils.…”

Nutrient acquisition from different soil depths by pedunculate oak

“…Penunculate oak (Quercus robur) has a deeper root system than Norway spruce (Rothe and Binkley 2001;Rosengren et al 2005), which means that a larger soil volume may be explored by roots for nutrient uptake. However, root distribution does not necessarily reflect the distribution of nutrient uptake; the density of root tips, the degree of mycorrhizal infection, the length of external mycorrhizal mycelia and different mycorrhizal species can also influence plant uptake capacity (George and Marschner 1996).…”