For many centuries primitive mankind existed in this region in a state of ecological equilibrium. It was not until the last few decades of this century that Pakistan experienced profound and accelerated ecological changes resulting from greatly increased human population, industrialization, massive deforestation, salinity and water-logging combined with progressive desertification, decline of living resources.
The industrial wastes and affluent, air and noise pollution, population explosion, rural population explosion, rural population\'s migration to urban slums, sanitation etc. have all contributed to degradation of quality of life. There is still time to affect reversal in this devastation, so that our future generations can lead prosperous and productive lives.
The most efficient way of the protection of natural heritage is the designation of Protected Areas (PAs). World Conservation Union (IUCN) have designated 10 categories of PA5 which include Scientific Reserve/strict Nature Reserve, National Park, Natural Monument/Natural Land-mark, managed Nature Reserve, Wildlife sanctuary, Protected Landscapes, Resource Re-serve, Natural Biotic Area/Anthropological Reserve, Multiple use Management Area/Managed Resource Area, Biosphere Reserve and World Heritage Site.
Designation of the National Parks (NPs) is the most common way of conserving the natural heritage. NPs are defined as the designated areas to protect natural and scenic areas of national and international significance for scientific, educational and recreational use. This is an area of land which is set aside primarily or exclusively for the conservation of wild animals and plants and their habitats in which human occupancy and the use of the biological resources is legally limited. The first NP - Yellowstone, in the United States was established in 1872. Since yellow stone\'s establishment most governments have recognised the value of PAs to their people, to date there are more than 5000 PA5 in the world covering nearly four million sq. km. established by 124 countries. Government of Pakistan recognizes the importance of the NPs and other PA5 and have so far designated 15 NPs, 86 wildlife Sanctuaries and 85 Game Reserves.
To mark the occasion Pakistan Post is issuing a stamp of Rs. 6/- denomination on April 20, 1995.