The theme of this year's observance of the 10th World Environment Day, declared by the United Nations, is 'Deserts and Desertification: Don't Desert Drylands!'

Acting President Barrister M Jamiruddin Sircar and Prime Minister Khaleda Zia issued messages calling for the people to wage a movement for preventing environmental pollution and protecting the environs.

Jamiruddin said, "Land, an important element of environment, has a great impact on our ecology, environs and lifecycles of animal and plant."

River erosion, climate change and increase in salinity in sea and river waters in the country puts cultivable land into desertification process, he said.

The acting president said desertification is hard to reverse, but it can be prevented through tree planting or using organic fertiliser on the deserted lands.

In a separate message, Khaleda Zia said Bangladesh is an agro-based country and livelihood of most countrymen depends on the crops cultivated on its land.

But, deforestation, lack of rainwater and navigability of the rivers and irrigation of cropland from the saline river waters turn Bangladesh's fertile lands into desert lands, she observed.

"We should be aware of the need for preservation of property and fertility of our cultivable land and prevention of desertification," said the PM.

The government and the greens have taken various programmes to observe the day.