The root herbivore history of the soil affects the productivity of a grassland plant community and determines plant response to new root herbivore attack.

Insect root herbivores can alter plant community structure by affecting the competitive ability of single plants. However, their effects can be modified by the soil environment. Root herbivory itself may induce changes in the soil biota community, and it has recently been shown that these changes can affect plant growth in a subsequent season or plant generation.

Rapid and accurate analyses of silicon and phosphorus in plants using a portable X-ray fluorescence spectrometer.

The elemental analysis of plant material is a frequently employed tool across biological disciplines, yet accurate, convenient and economical methods for the determination of some important elements are currently lacking. For instance, digestion-based techniques are often hazardous and time-consuming and, particularly in the case of silicon (Si), can suffer from low accuracy due to incomplete solubilization and potential volatilization, whilst other methods may require large, expensive and specialised equipment. Here, we present a rapid, safe and accurate procedure for the simultaneous, nonconsumptive analysis of Si and phosphorus (P) in as little as 0.

Delayed induced silica defences in grasses and their potential for destabilising herbivore population dynamics.

Some grass species mount a defensive response to grazing by increasing their rate of uptake of silica from the soil and depositing it as abrasive granules in their leaves. Increased plant silica levels reduce food quality for herbivores that feed on these grasses. Here we provide empirical evidence that a principal food species of an herbivorous rodent exhibits a delayed defensive response to grazing by increasing silica concentrations, and present theoretical modelling that predicts that such a response alone could lead to the population cycles observed in some herbivore populations.

Interactive effects of plant-available soil silicon and herbivory on competition between two grass species.

Background And Aims: The herbivore defence system of true grasses (Poaceae) is predominantly based on silicon that is taken up from the soil and deposited in the leaves in the form of abrasive phytoliths. Silicon uptake mechanisms can be both passive and active, with the latter suggesting that there is an energetic cost to silicon uptake. This study assessed the effects of plant-available soil silicon and herbivory on the competitive interactions between the grasses Poa annua, a species that has previously been reported to accumulate only small amounts of silicon, and Lolium perenne, a high silicon accumulator.