**3.6 Effect of climate change on plant: Pollinator interactions**

For the health of natural habitats, plant-pollinator interactions are important, and most of the human diet is dependent on pollination by insects. By altering the phenology, morphology, and distribution of plants and insects, components of Global Environmental Change (GEC), including higher temperatures, increased CO2 levels, and modified patterns of precipitation, can directly impact the interactions between plants and pollinators. Another important way where GEC factors can influence plant-pollinator interactions is the modification of phytochemicals (nectar and volatile chemistry) necessary for pollinator attraction (**Table 1**). Floral biogenic volatile organic compounds (BVOCs), that have a major function in attraction of the pollinators and plant-pollinator mutualisms, can be transformed by the components of global climate change. Most of the effects of temperature on floral BVOCs have been shown, with a consistent positive influence on global warming BVOC emissions. BVOCs are actively carried by a protein through the plasma membrane and expelled from the *Petunia hybrida* flowers [38], where the temperature and protein behaviour is always positively associated.

However, anthropogenic airborne pollutants such as ozone and diesel exhaust can destroy floral VOCs once released and increase the foraging times of pollinator. For instance, Farré-Armengol et al. [39] found that appropriate ozone levels in compound-specific ways degraded *Brassica nigra* floral BVOCs, altering the ratio of bouquet compounds that strongly inhibited the attraction of the generalist bumble bee pollinator*, Bombus terrestris*. It is apparent that airborne contaminants have major adverse effects often in unpredictable ways on the pollinator attraction towards flowers (eg. by changing BVOC ratios).
