3 characteristics used to delineate a wetland

• Wetland hydrology• Hydrophytic vegetation• Hydric soils

Wetland Hydrology

• Waterlogged ground– Saturation within 12 inches of surface

• Water marks on trees or grasses• Visible mud or dry mud cracks

Hydrophytic Vegetation• Adapted to anaerobic soils• Buttressed trunks• Shallow root system• Floating leaves• Specialized tissue (aerenchyma) that is spongy and

transports air from the leaves and stems to the roots

Hydric Soil

• Excessive moisture• Rotten egg odor (hydrogen sulfide_• A predominance of decomposed organic

matter• Gleyed coloring below surface or major color

of soil is dark and dull

Coral Reef Threats Nitrogen and phosphorus addition can fertilize algae and result in algal blooms. Because algae can potentially grow so much faster than coral, they can out-compete corals. Creation of unwanted algae covers the coral and does not allow the zooxanthellae to perform photosynthesis. Or an algal bloom above can lessen sunlight penetration – resulting in the zooxanthellae not receiving enough sunlight

Human activities on land such as the clearing of forests, road building, and other development can lead to increased rates of sedimentation. High sediment load can reduce light penetration and reduce the photosynthetic activity of zooxanthellae. The problem of sedimentation of coral reefs has been increased by the removal of mangrove and seagrass communities that naturally filter out sediments.

Coral Reef ThreatsIntroduction of invasive species such as the lionfish, can alter trophic interactions and cause unexpected indirect effects on the environment. For example, in areas where predators have been removed increases in population size of their prey have resulted in unintended effect on the environment. An increase in herbivorous fishes in the coral reef can overeat the macroalgae of the coral and thus indirectly decreasing the biodiversity of the coral reef.

Lionfish prey on herbivorous fishes that consume macroalgae and help protect corals from algal overgrowth.

As the ocean absorbs carbon dioxide, a greenhouse gas, from the atmosphere, it becomes more acidic and makes it difficult for polyps to create their skeletons. The calcification rates of corals and other reef organisms has already begun to decrease, leading to fears that reef building will not keep pace with climate change. With increased CO2 in the water, coral may form weaker skeletons, making them more vulnerable to storm damage, careless tourists, and destructive fishing practices.

Soils of terrestrial biomes

https://php.radford.edu/~swoodwar/biomes/