< RETURN TO CONTENTS < SEARCH 3.1. Why is the question important? 3.2. What resources are available? 3.2a National assessments 3.2b Vegetation clearance 3.2c Weeds and diseases 3.2d Altered fire and glazing regimes 3.2e Altered hydrology 3.2f Urbanisation 3.2g Climate change 3.2h Social and institutional pressures 3.2i Interacting threats 3.3. Where to from here? 3.3a Vegetation clearance 3.3b Weeds and diseases 3.3c Altered fire and grazing regimes 3.3d Altered hydrology 3.3e Urbanisation 3.3f Climate change 3.3g Social and institutional pressures 3.3h Interacting threats 3.2i Interacting threats The threats to native vegetation in this chapter have generally been dealt with as separate issues. This reflects how research is often undertaken, and the way people like to receive information. It is critical to recognise however that, at any site, typically a number of threatening processes may be operating together, with compounded or complex interactive effects. For example, the importance of the interaction between fire and other types of disturbance has been identified in a recent book chapter 288. The author concludes that fire, grazing and climatic variability can interact in a variety of ways to determine the state of vegetation in any given area, and grazing can also determine the post-fire regeneration success. This can lead to ecosystems reaching alternative states, depending on the history of disturbance and occurrence of climatic events. Interactions between grazing impacts on arthropods and levels of weed invasion in remnant woodlands have also been demonstrated 289. Interactions such as these are likely to be widespread, and demonstrate the importance of not considering threats in isolation.