In grazed habitats is a tradeoff between competition (decreases with the grazing intensity) and disturbance (increases). This may give tradeoffs between plant life stages. The seed production can be assumed to decrease at high disturbance intensities because of herbivory of reproductive organs, but also at high levels of competition (low grazing intensity) because of resource limitation. The es...

The pasture and animal productivity of established high producing pastures in the Waikato has been compared with newly sown pastures based on recently released herbage cultivars. The established pastures were a mixture of Nui perennial ryegrass, Paspalum dilatatum and Htiia white clover. The new cultivars tested were Ellett perennial ryegrass, Wana cocksfoot and Roa tall fescue, each sown with ...

The recent IPCC Fourth Assessment report concluded that Australia has significant vulnerability to the changes in temperature and rainfall projected under climate change (Hennessy et al. 2007). Agriculture and natural resources were two of the key sectors identified as likely to be affected strongly. Extensive grazing is by far the most widespread agricultural land use in Australia. Most of the...

In all animal models for chlamydial infection, there is strong evidence for immunity to reinfection; however, immunity is only complete (ie, preventing infection) in the short term. In the long term, animals are only partially immune (ie, they can be reinfected, but infections are usually abbreviated and less intense than the primary infection). This review will target the mechanisms responsibl...

Nutrient and grazing levels were manipulated in a 10 wk field experiment at 2 sites in a subtropical lagoon in Bermuda to evaluate their relative effects on the abundance and growth of the dominant seagrass and macroalgae. One site was eutrophic, the other mesotrophic to oligotrophc. Nutrients were added to the sediment-water interface using slow-release fertilizer, and the dominant herbivores ...