Mixed tree–grass vegetation is important globally at ecotones between grasslands and forests. To address uncertainties vis-à-vis productivity and nitrogen (N) cycling in such systems we studied 20 mature oak savanna stands, ranging from 90% woody dominated to 80% herbaceous dominated, growing on comparable soils in a 32-yr-old fire frequency experiment in Minnesota, USA. Fire frequencies ranged...

in order to identification of allelopathic compounds and investigation of the effect of aerial part extract of orchard grass on germination and seedling growth of alfalfa an experiment conducted as completely randomized design with four replications at university of mohaghegh ardabili, iran. treatments were concentrations of orchard grass extracts including 0, 25, 50, 75, and 100%. radicle and ...

.........................................................................................................................................................................1 Roadside Drainage Design for Channel Stability ..........................................................................................................2 Allowable Velocity and Shear Stress.......................................

A llelopathy is defined by most scientists as the adverse effect of one plant species on another through production of phytotoxins (allelochemicals), although more expansive definitions have been formulated. Allelopathy is but one component of plant/plant interference, the other being competition for resources such as nutrients, light, and water. Allelopathy has been a recognized phenomenon for...

BACKGROUNDS AND AIMS Leaf functional traits have been used as a basis to categoize plants across a range of resource-use specialization, from those that conserve available resources to those that exploit them. However, the extent to which the leaf functional traits used to define the resource-use strategies are related to root traits and are good indicators of the ability of the roots to take u...

In semiarid or arid conditions, the change of root-zone soil moisture can be almost instantaneously reflected by vegetation through biophysical process. This study investigated feasibility of mapping root-zone soil moisture using MODIS-derived NDVI via statistic approach at three sites (New Mexico, Arizona, and Texas) selected from the Soil Climate Analysis Network (SCAN). These three sites rep...

1. We studied the differences in root strength of species with contrasting root structural types (the grass Paspalum dilatatum and the dicot Lotus glaber ), and their relationship with tolerance to simulated cattle trampling under flooding conditions. 2. Root strength was analysed through measurement of the pressure required to cause root collapse. The responses of aerenchyma and plant mass to ...

Aboveand belowground biomass of contrasting grass growth forms (Hilaria belangeri— shortgrass vs. Bouteloua curtipendula—mid-height grass) was quantified with respect to partial root barriers (at 35 cm soil depth) with artificial fissures. We hypothesized (a) growth would be greatest in the absence of a barrier; and (b) the shallow-rooted H. belangeri would be relatively less affected by barrie...