Invasive species

My most recent interest is about the importance of invasive species and how these affect the concept of Gaia. If we consider that life actually created the earth as we know it today and we change that life we will also change Gaia, I call this invasion of the worlds ecosystems with plant and animals that are alien to the various ecosystems the 'Globalisation of fauna and flora'Many years ago I did research into how natural grassland became invaded with pioneer plants when the fertility status was changed by adding fertilizer.The pioneer plants were both broad leaved'weeds' and grasses.

This is how the grassland looked in pristine condition as it had evolved over millions of years with the dominant species (Plot 6) Themeda triandra









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After the application of heavy dressings of nitrogen fertilizer this is what it looked like.The weeds were seeds brought in by various means, probably by wind. The climax grassland is not easily invaded unless disturbed in some way or another. Mostly climax grasses disappear through selective over grazing, This has been brought about through intensive farming with cattle and sheep with the erection of fences and the complete absence of native grazers. In the above case the climax grasses actually died out leaving bare patches before the invading plants came in so they were not out competed.