FAQ's about Vegetation

Systematics, or taxonomy, is the branch of biological sciences that deals with the identification, description, naming, and classification of the world's biota. Taxonomic information can be found through the National Biological Information Infrastructure (the NBII) at http://www.nbii.gov. Quoting their website, "The National Biological Information Infrastructure is a broad, collaborative program to provide increased access to data and information on the [world's] biological resources." From their homepage there is a link to the Systematics website, where you can find a number of excellent sources for the information about the scientific names of plants and animals, including the Integrated Taxonomic Information System, or ITIS. ITIS is a partnership of federal and international agencies, and other organizations, as well as, taxonomic specialists cooperating on the development of an online, scientifically credible list of biological names focusing on the biota of North America. The ITIS is also a participating member of Species 2000, an international project indexing the world's known species.

There are 15 essential elements to all animals and plants, these include: Hydrogen(H) Carbon (C) Nitrogen (N) Oxygen (O) Sodium (Na) Magnesium(Mg) Phosphorus(P) Sulfur(S) Chlorine (C) Potassium (K) Calcium (Ca) Manganese (Mn) Iron (Fe) Copper (Cu) Zinc (Zn), and Selenium (Se)

To view maps of volcanoes visit the USGS online store at http://store.usgs.gov/ and look under the heading Maps>Hazards.

Trace essential elements such as fluorine, copper, selenium, molybdenum, and others can be hazardous to living organisms if present at high levels. Nonessential heavy metals such as arsenic, lead, mercury, cadmium, chromium are usually toxic to organisms as much lower levels than trace essential elements. Depending on the association that these nonessential elements may form with natural geologic materials such as organic matter, other elements or minerals, and adsorbers (such as clays), these elements can range from being safe to being extremely toxic.

Because of growing public concern about the environmental contamination, it is becoming increasingly important to better understand both the natural and human processes that control the movement of elements at the Earth's surface. Elements can be quite mobile in water, and the majority of our environmental problems are ultimately associated with the contamination of surface and ground water.

When water comes into contact with rocks and soils, some of the minerals and organic substances dissolve and enter the natural waters. Forests and grasslands generally contribute only small amounts of these dissolved substances. However, it is possible for an area to contain unusually high concentrations of minerals, thereby depositing them to the waterways. For example, swamps and marshes often produce acidic and colored water. Other areas that contributed natural pollutants to water are those containing rocks with sulfide minerals, particularly pyrite.

Inorganic substance are cycled naturally through our environment at concentrations that usually do no adversely affect plants and animals. However, the combination of some natural processes with human activities can increase these substances to harmful or toxic levels. Therefore, toxic substances may have both natural and human sources.

Natural sources of toxic substance include rocks, volcanoes, sediments, and soils. Human activities that add toxic substances to the environment include smelting, manufacturing, refining, chemical processing, fertilizer application, irrigation, and waste disposal.

A large concentration of a substance commonly identifies a source of pollution but may not necessarily indicate a problem. In addition to the concentration, other characteristics of the substance must be considered. These characteristics include the amount of the substance released, the rate of release, its availability to organisms, and its residence time in a particular ecosystem. (From USGS Circular 1105.)

First of all, plants naturally grow in and around lakes. Maybe you're asking about a lake that is being choked off by too much algae. In many cases, humans are responsible. Actually, these lakes are being fed too much food for plants! There are certain chemicals we use that are nutrients (food) to plants. At our homes we fertilize our yards with nitrogen, potassium, and phosphorus. These chemicals wash off our lawns and eventually get into the water system, such as into creeks, rivers, and lakes. Once there, algae and plants have a feast on this "food". Things used to be worse for our water bodies. Phosphorus used to be an ingredient in our laundry detergent, but this has generally been phased out.

Wetland mapping information is available from the National Wetlands Inventory Center of the U.S. Fish & Wildlife Service, St. Petersburg, Florida.

Telephone: 727-570-5420

FAX: 727-570-5420

URL: http://www.fws.gov/nwi/

Digital wetland data are available through the Wetlands Mapper. Paper copies of wetland maps are available from various state sources.

Several of these trace elements are regulated by the EPA and are on their list of primary drinking water standards. These include arsenic, copper, and lead, as well as cadmium, chromium, mercury, and selenium. Iron is not a regulated contaminant because it is not known to cause health problems, but there is a secondary drinking water standard based on its tendency to stain laundry and plumbing fixtures. Manganese, copper (again), silver, and zinc are also included in the secondary standards. The primary and secondary standards are available on the EPA Web page Current Drinking Water Standards.

The above standards are national drinking water standards. Other water-quality standards are set by states to protect aquatic life. You can check with your state environmental or natural resources agency to see what aquatic life water-quality standards are in effect in your state. EPA is currently reviewing its recommendations for aquatic life criteria. The existing criteria are found at http://www.epa.gov/OST/standards/wqcriteria.html and more information on the current review of standards is available on Aquatic Life Water Quality Criteria.

The USGS National Analysis of Trace Elements also has current information on trace elements across the United States, including links to specific studies and current items in the news.

Chinese tallow has the ability to reach reproductive age in as little as 3 years and to remain productive for at least 60 years. It does not seem to have a preference for disturbed areas over undisturbed areas and can grow in a variety of places. It can also grow in both full sunlight and shade. It is more tolerant of salinity and flooding than quite a few other native species. It grows in subtropical to warm climates but is hardy and able to withstand a few degrees of frost. It is able to thrive in the United States and is resistant to native insects. In addition, it is somewhat resistant to fire.

Regulatory limits for safe levels of elements in water and foodstuffs are established by the U.S. Environmental Protection Agency and the U. S. Food and Drug Administration. However, there are generally no regulatory limits that scientists can refer to when dealing with plants, soils, rocks, and sediments. Therefore, to determine whether a plant, soil, rock, or sediment contains a "high or unusual" quantity of a specific element, it is necessary to determine what quantity is "normal or usual." These levels are referred to as background or baseline measurements, but they may be somewhat different.

A background measurement represents natural concentrations of an element in natural materials that exclude human influence. This measurement represents an idealized situation and is typically more difficult to measure than a baseline.

A baseline measurement represents concentrations measured at some point in time and is not generally a true background. Baseline concentrations are typically expressed as a range, not a single value. (From USGS Circular 1105.)

Brown Marsh is a term that Louisiana scientists have given to the rapid and unusual browning of Louisiana's intertidal smooth cordgrass (Spartina alterniflora) marshes. This browning began during the spring of 2000, long before it would normally occur in the fall.

Wetlands are transitional areas, sandwiched between permanently flooded deepwater environments and well-drained uplands. They include mangroves, marshes (salt, brackish, intermediate, and fresh), swamps, forested wetlands, bogs, wet prairies, prairie potholes, and vernal pools. They often contain more plants and animals and produce more organic material than either the adjacent water or land areas. Aquatic habitats include permanently flooded parts of estuaries and nearshore environments like seagrass beds, rivers, ponds, and lakes. Aquatic habitats are also critical to fish and wildlife as well as economically and recreationally valuable to humans.

Wetlands are among the most productive habitats on earth providing shelter and nursery areas for commercially and recreationally important animals like fish and shellfish, as well as wintering grounds for migrating birds. Coastal marshes are particularly valuable for preventing loss of life and property by moderating extreme floods and buffering the land from storms; they also form natural reservoirs and help maintain desirable water quality.

Aquatic habitats like those along the Gulf of Mexico are vital to seabirds, fish, and shellfish; economically the gulf alone contributes billions to the economy. Riverine deep water—like the Mississippi River and its many channels—is not only essential for navigation, industry, and recreation and therefore responsible for billions of dollars to the economy, but is also invaluable for natural resources. Songbirds and waterfowl use rivers as migratory guides, and rivers and lakes are both essential to countless species of fish, amphibians like frogs and salamanders, and reptiles like turtles, snakes, and alligators.

Wetlands have come under natural and human threats (from subsiding or sinking land to draining or filling for new development). Scientists estimate that the lower 48 United States have lost more than half of their wetlands since colonial times.

Coastal wetlands especially have been seriously threatened. For example, Louisiana alone has 40 percent of the coastal wetlands in the lower 48 States and is still losing from 25 to 35 square miles a year of wetlands to open water because of erosion and subsidence.

In addition to coastal wetlands, seagrasses in the estuaries along the coast of the Gulf of Mexico and worldwide have been depleted. Serious problems also include the tremendous loss of forested wetlands in the South; while they account for more than a third of all wetlands in the lower 48 States, they also account for two thirds of the annual loss of all wetlands in the continental United States. Wildlife, especially migratory birds like waterfowl and Neotropical birds have experienced population declines and distributional shifts, partly because of habitat alteration.

Rivers and other aquatic habitats have also undergone huge changes. They suffer impacts from various causes, ranging from dredging to both point and nonpoint source pollutants to contaminants. Estuaries have also seen enormous changes in water quality and structure from dredging, fringing urban development, industries, and shipping. All of these, in turn, change the ecological structure and functions of these habitats and their ability to support fish, shellfish, and wildlife.

Restoring these wetlands and improving aquatic habitats have become imperative to maintaining an ecological balance. To restore and manage these valuable wetlands and deepwater habitats, however, requires scientific research because much remains unknown about which restoration and management techniques work best and how restored ecosystems work compared to natural ones.

The coastal prairie, located along the coastal plain of southwestern Louisiana and southcentral Texas, is the southernmost tip of the tallgrass prairie ecosystem so prevalent in the Midwest. This region is distinctive from the Midwestern grasslands in the amount of rainfall: 142.24 cm (56 inches) annually compared to a mere 71 cm (28 inches) in the Midwest. Such an abundant amount of rainfall typically produces forests rather than grasslands; scientists believe that the coastal prairie developed because of the hard clay layer underneath the topsoil, which inhibited root formation of larger species such as forest trees. Before settlement, natural fires such as those set by lightning also contributed to keeping the growth of trees and shrubs in check while stimulating the growth of native grasses.

While scientists have not completed their investigations, they believe that extreme drought, high salinities, heat, evaporation, combined with extremely low Mississippi and Atchafalaya River discharges have stressed the shallow rooted Spartina alterniflora.

Water management in the Mississippi River delta has focused on preventing flood conditions during the last 100 years. The engineered flood plain of the Mississippi River in Louisiana limits the release of fresh water to wetland areas. The lack of freshwater flow may lead to a more severe response of coastal wetlands under drought conditions.

Yes, some regeneration of "moderately impacted" marsh has been observed.

There is great concern that the dead marsh areas could be seriously affected by major storm events. Local, state, and federal agencies are working together to determine what, if any, short-term measures can be implemented, and to put in place long-term remediation strategies. The Governor's Office has requested consideration of an emergency funding allocation through federal sources to provide for immediate assistance.

Coastal marshes provide essential habitat and nurseries for fish and habitat for migratory and nonmigratory birds, mammals, reptiles, and amphibians. Scientists cannot at this time predict the effects on specific populations, although any loss of these important intertidal marshes is sure to lead to a longterm decline in habitat.