Unit 9: Biodiversity Decline // Visuals

Animation(s)

Changes in forest biomass: Plots within 100 meters of a rain forest edge lost up to 36% of their biomass of old growth tree species within the first 10-17 years of fragmentation. View animation
Encroaching edges: Vines start to smother trees near the forest edge and kill them. View animation
Fish per hook: In a period of 25 to 30 years in the entire global ocean, the catch was depleted from 10 fish per hundred hooks to one fish per hundred hooks. View animation
Fishing reserves: Sites designated as marine reserves had the greatest levels in total fish biomass compared to sites that had been historically overfished. View animation
Forest fragments: Destruction or habitat loss has broken large rainforests up into many smaller habitat fragments. View animation
Shifting baseline syndrome: The baseline created by fisheries biologists 30 years ago was 10 percent of the baseline of fisheries biologists from the generation before. View animation
The rise of slime: Overfishing completely changes an ecosystem from one that is healthy and diverse to one that is only attractive to bacteria and jellyfish. View animation

Photograph(s)

Buried machinery in barn lot. Dallas, South Dakota, 1936: The Dust Bowl stimulated interest in conservation tillage methods, which leave crop residues in place to reduce soil erosion and prevent topsoil loss. View image
Colonization by zebra mussels, Great Lakes: Zebra mussels can survive in many aquatic environments and breed prolifically. Originally found in Russia, they have spread throughout the Great Lakes and the Mississippi, Ohio, Tennessee, and Hudson river basins. View image
Color variation in the Oldfield mouse (Peromyscus polionotus): The Oldfield mouse lives in dry soils in the southeastern United States. Its color varies greatly and correlates with soil and leaf litter. View image
Habitat fragmentation and species mobility: Development in rural areas has made traffic a growing threat to bears and other species in the United States. View image
Landsat image of invasive salt cedar, 2002: Invasive salt cedar along the Forgotten River segment of the Rio Grande in Hudspeth County, Texas and Chihuahua State, Mexico. Yellow areas indicate high probability of salt cedar infestation. View image
Suburban development in Douglas County, Colorado: Located between Colorado’s two largest cities, Denver and Colorado Springs, Douglas County has been among the fastest-growing counties in the United States in recent years. View image
Tomato frog (Dyscophus antongilii). Listed on CITES Appendix 1 (threatened with extinction): Tomato frogs, which are found only along the northern coast of Madagascar, are endangered by habitat destruction and over-collecting for sale as pets. View image

Graphic(s)

Arctic marine food web: The communities that form the base of Arctic marine food chains are uniquely adapted to conditions under the ice, including wide fluctuations in light, temperature, and salinity levels, and constant change in the extent and thickness of ice cover. View image
Atlantic piping plover recovery trends: Piping plovers nest and feed on outer beaches along the Atlantic coast. Coastal development, human disturbance, and harassment from pets are major threats to plovers. View image
Biodiversity hotspots: Biodiversity hotspots cover a small fraction of Earth’s surface but are home to large numbers of living species. View image
Earth's five mass extinctions: Earth has experienced five major mass extinctions in the past half-billion years. Although it is not reflected on this graph, scientists think a sixth mass extinction may be under way. View image
Passenger pigeons, from John James Audubon’s Birds of America: In 1813, naturalist John James Audubon called passenger pigeons “wonderfully abundant.” A century later the species was extinct. View image
Roles played by soil organisms: Soil is one of the most diverse habitats on earth. Many tiny organisms play important roles in maintaining soil quality. View image
Terrestrial habitat transformation: Between 40 to 80 percent of many habitat types may be converted for human use by 2050. The projected gain in temperate forest lands is due to reforestation on land formerly cleared for farms. View image
Three domains of life: Although Earth’s most complex life forms are Eukarya, the microbial world contains much of our planet’s biodiversity. View image
Time table of the evolution of complex life forms on Earth: Complex life forms appeared on Earth relatively late in geologic time, but diversified rapidly. View image
Watercolor painting of Ivory-billed Woodpeckers by John James Audubon: Reported sightings of Ivory-billed Woodpeckers over the past several years have raised hopes that habitat conservation measures could still preserve the species. View image
Western Hemisphere locations for the Christmas Bird Count: The annual Audubon Christmas Bird Count started in 1900 as an alternative to traditional Christmas Day hunting contests. Today more than 50,000 volunteers take part yearly. View image

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