The biodiversity and constituent ecosystems, are critically important to our well-being and economic situation, Yemen has a rich variety of both biodiversity and landscapes, reflecting the variety in geology and altitudes found within the country. As elsewhere in the world, biodiversity in Yemen has an important environmental role; ecosystems act to regulate current and water regimes, and influence climate. Biodiversity has an important role in maintaining atmospheric air quality and in ensuring a healthy ecological environment for humans. Elements of biodiversity also act to protect the soil from erosion. Humans have hunted, fished and gathered the plants and animals of Yemen since ancient times. Intensive use of natural resources continues today.