Monday, 22 October 2007

Plants are Amazing- Series One

Nearly everyday now we learn something new about the ways we can save water and energy around the home to reduce our impact on the environment, and ultimately help minimise our effects on climate change. So every now and then it’s nice to sit back and appreciate the amazing things that nature has to offer and some of the cool ways our environment deals with the harsh Australian climate. In particular, many Australian plants have special adaptations that help them survive periods of drought, extreme summer temperatures, fire, or highly saline soils.

Within the Western Sydney region plants have to contend with low, highly variable rainfall, high summer temperatures, relatively frequent wildfire events, and infertile soils. These plants have adapted to these conditions be evolving a suit of structural, biochemical or growth response adaptations.

One way that plants have adapted to this is with special root system modifications. Root adaptations include the development of water storing roots in plants such as Mallees. Structural and biochemical changes in these plants allow the roots to store supplies of water harvested after big rain events, so that these plants can survive better during long drought periods. Other plants have modified root systems called tubers where stores of nutrients are held, allowing the above ground part of these plants to die off during drought times and then regrow after rain.


Some other species (for example Hakeas and Grevilleas) have root modifications (called proteoid roots) that allow them to extract phosphorous from our low fertility soils. Many legumes (wattles, pea family plants) have evolved a relationship with nitrogen-fixing bacteria that amass in nodules along their roots and make atmospheric nitrogen available to plants after the host plants has died.

Each fortnight, as part of the ‘Plants are Amazing’ series, another adaptation will be revealed, so stay tuned in the coming weeks for more cool adaptations our plants have developed.
Image from: Australian Plants Society Tasmania

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