MBGnet - Descriptions and images of the biomes of the world, freshwater ecosystems, and marine ecosystems. From the Missouri Botanical Garden. The World's Biomes - Introduction to aquatic, desert, forest, grassland, and tundra biomes. School class project. WorldBiomes - Covering five of the major world biomes. Biodiversity and Mutualism in Ecosystems - Technical paper on the importance of biodiversity and mutualism (co-operation between different species) to ecosystem function and structural organization. Terrestrial Ecoregions of the World - Maps, descriptions, and index to 687 ecoregions across the globe. Javascript required. Images of the Dry Tropics - Photographs of plants, animals, and landscapes from dry tropical habitats in the Americas, Africa, Madagascar, and Asia. Dry tropical habitat types include tropical dry forest, tropical deciduous forest, thorn forest, spiny desert, savannah, cerrado, and caatinga. Ecosystems Classification and Mapping - The World Institute for Conservation and Environment, WICE, provides information, tools and resources. Comprehensive Protected Areas System Composition and Monitoring - IUCN task force report on methods for optimizing national protected areas systems that maximise species conservation through targeted selection based on broadly accepted ecological principles. The Principles of the Transboundary System of Nature Environment Protection: The Upper Bug - Project to protect the ecosystems of the Western Bug basin, on the boundary between Poland and Ukraine, by collaboration between the two countries.