Due to the great variety in terrain and climate the Mid-Hills and high Mountains contain the greatest diversity of ecosystems and species in Nepal. Most of the 300 endemic species are found in these regions. Although population pressures are not as great as in the lowlands, the damaging effects of increasing cultivation and grazing are profoundly affecting these areas. These are compounded by the global effects of climate change, with glacial retreat and changing patterns in water supply. Inventory and conservation efforts are more difficult in these regions due to their remoteness and difficult terrain. The Mid-Hills are poorly represented in the current protected area network (see below). Sagarmatha National Park has been designated as a natural World Heritage Site.