In recent years, with growing understanding about the importance of conservation and strong efforts from government and environmentalists to promote conservation, increasing attention has been given to conserving Taiwan’s mangrove plants. In order to increase public awareness and education about the mangrove plants of Taiwan, Chunghwa Post is issuing a set of four stamps based on the four mangrove plant species found in Taiwan: Kandelia obovata, Rhizophora stylosa, Avicennia marina and Lumnitzera racemosa. In the background of each stamp is an example of the plant species in a stand. In the forefront of each stamp are the fruits or the viviparous propagules of the plant. And the flowers are shown in close-up on a solid blue background in a circular frame. The designs were planned by Yang Yuen-po, a professor of biological sciences at National Sun Yat-sen University, and Dr. Hsu Chiu-jung. Mangrove forests refer to evergreen shrubs or trees that grow in estuaries or coastal swamps where the water is salty or where salt water meets fresh water. Flooded by daily tides, these plants spend a lot of time immersed in water. Hence, mangrove forests are also called tidal forests. To withstand the high salinity and low oxygen of their growing environment, as well as to anchor themselves in the mud flats and to withstand the force of the tides and river currents, these plants have developed unique physical adaptations, including prop roots, pneumatophores and viviparous propagules. Mangrove plants are important parts of estuary ecosystems, providing habitat for many kinds of animals.Six kinds of mangrove plants have been found in Taiwan. The cold hardy Kandelia obovata is the only species found in northern Taiwan; the remaining mangrove plants are all found in middle and southern Taiwan. As a result of modern encroachments— namely land developments, fish farms, the building of embankments and lifestyles changes among local residents—the total area of mangrove forests in Taiwan has decreased drastically. After the development of Kaohsiung Harbor, Bruguiera gymnorrhiza and Ceriops tagal became extinct while Rhizophora stylosa and Lumnitzera racemosa are endangered.