Der Verzweigungsindex, ein Indikator für Schäden am Feinwurzelsystem

Fine roots and ectomycorrhizas as indicators of environmental change

“…Further research is evidently needed. Similarly the branching index (Meyer, 1987) was suggested to decline under the influence of environmental stress (acid rain, N deposition). There were too few data available to judge the usefulness of this indicator.…”

“…Pigott (1982) carefully showed that Cenococcum survived better than other mycorrhizal fungi during a drought episode. It is also possible that the mycelium of Cenococcum is more persistent to decomposition than that of some other species (Meyer, 1987). Furthermore, the concepts of taxonomy of this fungus have varied with time, and the morphological identification is not easy because of easy confusion with other fungi.…”

“…Specific root length (SRL, root length per unit root weight) was proposed by Fitter (1976Fitter ( , 1985 as a parameter that both expresses nutrient uptake benefits (length scales with surface area over which nutrients are taken up) and construction and maintenance costs (which scales with biomass, being a function of root tissue density and root tip diameter, cf Ostonen et al, Pl Biosyst 2007, submitted). Other potentially useful aggregate parameters could include fractional colonization (the fraction of root tips that is ECM or the fraction of root length that is ECM), number of root tips per volume of soil, length of ECM roots, weight of ECM roots, and branching index (the number of mycorrhizal root tips per unit root length; Meyer, 1987). Finally, fungal characters referring to the ecological strategies of the fungi involved (e.g.…”

Needle and root responses of small Pinus sylvestris seedlings exposed to sulphur dioxide and simulated acid rain

“…These injuries in Picea abies include poor growth of long and short roots, decreased ramification, decrease of cell size in the cortex, decline of mycorrhizas, and at the cellular level an accumulation of phenolic substances both in cortical cells and stelar parenchyma tissue (Liss et al, 1984;Stienen et al, 1984;Meyer, 1987). However, knowledge of ultrastructural changes in conifer roots is still limited (Kottke et al, 1986) and there is a great need for information on the structural effects of experimentally applied single stress factors.…”

Interactions between exposure to O3 and nutrient status of trees: effects on nutrient content and uptake, growth, mycorrhiza and needle ultrastructure

“…The root ramification index, the total number of short roots against root length, has successfully been used for describing the effects of pollution on the vitality of conifer root systems (e.g. Meyer, 1987). In the present study all the lateral branches with the length < 1 cm were regarded as short roots.…”