Five to seven years after being graded by first-order lateral root (FOLR) numbers and outplanted, loblolly pine (Pinus taeda L.) seedlings were excavated using a commercial tree spade and root systems re-evaluated. Current competitive position of trees was related to initial FOLR numbers of I-O seedlings. Current FOLR numbers were comparable among tree size classes, but root diameters where the...

BACKGROUND AND AIMS Plant biomass-density relationships during self-thinning are determined mainly by allometry. Both allometry and biomass-density relationship have been shown to vary with abiotic conditions, but the effects of biotic interactions have not been investigated. Arbuscular mycorrhizal fungi (AMF) can promote plant growth and affect plant form. Here experiments were carried out to ...

1. Plant functional composition may indirectly affect fine root processes both qualitatively (e.g. by influencing root chemistry) and quantitatively (e.g. by influencing root biomass and thus soil carbon (C) inputs and the soil environment). Despite the potential implications for ecosystem nitrogen (N) cycling, few studies have addressed the linkages between plant functional composition, root d...

late-season drought is the major constraint reducing the productivity of chickpea. this experiment was carried out to study response of root and shoot characteristics in 12 chickpea genotypes to drought stress. two-drought stress levels (-3 and -6 bar) induced by peg 6000 and control in hydroponic condition at green house was performed. leaf relative water content (rwc), plant height, number of...

We investigated the impact of drought and arbuscular mycorrhizal (AM) fungi on the morphological structure and physiological function of shoots and roots of male and female seedlings of the dioecious plant Populus cathayana Rehder. Pot-grown seedlings were subjected to well watered or water-limiting conditions (drought) and were grown in soil that was either inoculated or not inoculated with th...

Variations in ectomycorrhizal (EcM) short root tips of Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) in 16 stands throughout Finland were studied, and their relationships with latitude, organic layer C:N ratio, temperature sum and foliage biomass were determined. There were no significant differences in EcM root tip frequency (number per milligram of fine roots) o...

18 Improving arable crops Nitrogen Use Efficiency (NUE) is a major target of plant breeding. In 19 wheat, a large part of the Nitrogen (N) harvested in the grain originates from N remobilization 20 from vegetative organs during the post-anthesis period. While N remobilization from above-21 ground organs such as leaves and stems has been extensively studied, studies about N 22 remobilization fro...

Root nodulation in actinorhizal plants, like Discaria trinervis and Alnus incana, is subject to feedback regulatory mechanisms that control infection by Frankia and nodule development. Nodule pattern in the root system is controlled by an autoregulatory process that is induced soon after inoculation with Frankia. The final number of nodules, as well as nodule biomass in relation to plant biomas...

22 Humid tropical forests support large stocks of surface soil carbon (C) that exhibit high 23 spatial variability over scales of meters to landscapes (km). Reactive minerals and organo-metal 24 complexes are known to contribute to C accumulation in these ecosystems, although potential 25 interactions with environmental factors such as oxygen (O2) availability have received much less 26 attenti...