In woody plants, pioneer roots are the main roots used to expand the root system horizontally and vertically whereas fibrous 'feeder' roots are chiefly used in the absorption of water and nutrients. Because of their different roles, we expected newly emerged pioneer and fibrous roots to respond differently to restrictions in soil moisture. We hypothesized that fibrous roots would exhibit greate...

Plant roots growing through soil typically encounter considerable structural heterogeneity, and local variations in soil dry bulk density. The way the in situ architecture of root systems of different species respond to such heterogeneity is poorly understood due to challenges in visualising roots growing in soil. The objective of this study was to visualise and quantify the impact of abrupt ch...

Introduction Increasing atmospheric N deposition and changes in precipitation patterns could profoundly impact forest community structure ecosystem functions. However, most water (W) addition experiments have focused on direct application to leaf litter or soil, neglecting canopy processes such as evaporation absorption. Methods In this study, we aimed assess the effects of increased fine root ...

Soil erosion by water is commonly recognized as the one of main reasons of land degradation worldwide (e.g. Ananda & Herath, 2003; Beskow et al., 2009; Valentin et al., 2005). Most of the involved areas are occupied by various agricultural activities but pastures, forestry, unpaved roads as well as construction sites are also endangered by water erosion (Ananda & Herath, 2003; Arnanez et al., 2...

A large number of Gram-negative, motile, mesophilic, violacein-producing bacteria were isolated from the soils and roots of Vaccinium macrocarpon Ait. and Kalmia angustifolia L. plants and from irrigation ponds associated with wild and cultivated cranberry bogs in Massachusetts, USA. Phylogenetic analyses of 16S rRNA gene sequences placed these isolates in a clade with Chromobacterium species, ...

The evolution of soil structure after a forest fire was studied on two zones representatives of a typical Mediterranean Pine forest. These zones were in opposite slope orientation but with similar topographical and pedological characteristics. Changes in soil macro-aggregation and water stable micro-aggregation were monitored seasonally during a year after the fire. The water erosion patterns w...

According to the IPCC, global temperatures are expected to increase between 1.1 and 6.4 °C during the 21st century and precipitation patterns will be altered. Soils are intricately linked to the atmospheric/climate system through the carbon, nitrogen, and hydrologic cycles. Because of this, altered climate will have an effect on soil processes and properties. Recent studies indicate at least so...

The main challenge to restoration in Iceland is vast areas of severely degraded land that has limited resource retention and limited ecosystem functioning. These are often hostile environments for plant establishment and survival, due to unstable surfaces that are prone to intensive cryoturbation and erosion by wind and have limited water-holding capacity. Most of the degraded rangelands are op...

Soil loss from dryland farms on the Columbia Plateau in Oregon and Washington (USA) results primarily from rain falling on frozen, cultivated soil. Soils are most susceptible to erosion when moldboard plowed, summer-fallowed, repeatedly rodweeded or cultivated, and fall planted to winter-wheat. These tillage practices are used because they help control weed and disease infestations and consiste...

We investigate the morphology and dynamics of the region invaded by air injected at the bottom of an immersed granular bed. Previous experimental results point out the formation of a fluidized zone with a parabolic shape which does not depend, in the stationary regime, on the injection flow-rate. By tilting the experiment, we can tune the effective gravity in the system. We show that it does no...