Tuesday, August 24, 2010

How do plants survive in the desert?


C4 cycle.
WINDOW PLANT

HONEY MESQUITE


YELLOW DAISY FOUND IN THE DESERT


These 'Desert plants' have lots of special features to help them survive in the desert. One example is that:
-They have very long roots to reach far below in the ground to obtain as much water as possible.-> Mesquite has roots as long as 50m. Mesquite belongs to the Legume family- restores nitrogen to the soil. There are 3 common species of mesquite: Honey Mesquite, Screwbean Mesquite and Velvet Mesquite.
-Tough outer coats and painful thorns to prevent animals of the desert from trying to eat the plant for its water supply.
-Pebble plants grow partially underground to avoid the heat-> they are neat little plants that are mistaken for pebbles and are usually white or yellow.
-Window plants grow entirely underground-> window plant have a long cigar shape poking into the ground with only a small green part "leaf" to absorb sunlight.
-Mosses and lichens soak up dew.
-Trees with shrivelled, brown and dead looking most of the time then suddenly turns green when there is rain are called RESSURECTION TREES -> flower of a Jericho is a dry ball that can live for years and opens when damp.
-Daisies are found in most deserts-> Yellow desert daisies are cushion plants that grow to 5-20cm. They flower from May to June. These daisies maximize the energy gained from the process of photosynthesis. (C4 cycle) The C4 cycle, another, efficient pathway used by plants living in areas with low levels of carbon dioxide, to convert carbon dioxide into a form usable by the plants during photosynthesis.
-Cacti and Ice plants store water. -> Ice plants are now considered as invasive species. They are strong and reproduce quickly, easily growing into a thick ground cover that wipes out other plant life and depletes soil nutrients. The only way to control ice plant is to uproot it physically. These Ice plants are pinkish-purple in colour and have long and thin petals.
-Saguaro Cactus: These cacti are large in size and have an expandable stem that helps them to store water. During rainy season, water is absorbed by a large network of roots which is then stored in the expandable stems. This cacti has a long lifespan and grows very fast.
-Old Man Cactus: It has fine, white hair on its stems. The silvery, white hair on the stems of the cacti reflect the sun, thus preventing excess loss of water.
-Tumbleweed: Young plants are bright green in color and grow close to the soil surface. As the plant grows it develops ridged branches with thin needle like spikes. After maturity the tumbleweed becomes a dull green with transparent flowers and tiny leaves.
- Barrel Cactus: These cacti are shaped like a barrel and grow up to a height of about 1 meter. The cacti has many long, yellowish spines that store water during the rains. When the climate is hot and dry, these spines shrink in size as an adaptive technique.
www.buzzle.com
www.wikipedia.org
www.australiandesert.com
Reference book: 1000 plants