Conservation terms that describe species

Keystone Species:

A keystone species plays a crucial role in the functions of a healthy ecosystem. Without them, the system would be drastically altered or even cease to exist. The contributions of a keystone species are large and doesn’t always match the species’ prevalence in the habitat.

If a keystone species disappears; a domino effect begins to happen and other species that rely on that keystone, would change. One example would be if a large predator is removed from a system where deer lived;  deer populations could explode. The ecosystem cannot support that many animals. Competition for food and other resources would result among the deer themselves; their populations would decline and overall fitness levels would lower in the herds.

You can read an article published on Huff Post that discusses this issue further by clicking this link.

Foundation Species

Foundation species have major role in maintaining or even creating a habitat that supports other species. A great example of this would be corals. Corals produce the reef structures that countless species live and depend on.

Umbrella Species

An umbrella species is very similar to a keystone species. Many umbrella species are migratory and their daily activities help shape and maintain a balance to the ecosystem. By protecting an umbrella species, you are automatically protecting a number of other species who rely on that particular species.

Indicator Species

An indicator species is very sensitive to environmental changes in its ecosystem. By monitoring these species, conservationist can get early warning signs of habitat changes. External influences from changes in air, water or climate present themselves to these indicator species first.

Reference: National Geographic

Image: http://en.wikipedia.org/wiki/African_elephant#/media/File:African_Bush_Elephant.jpg

Understanding infectious diseases

Understanding how infections and diseases spread can be very challenging. Here are some terms that can help. (Medecinenet.com)

Infection: The invasion and multiplication of microorganisms such as bacteria, viruses, and parasites that are not normally present within the body. An infection may cause no symptoms and be subclinical, or it may cause symptoms and be clinically apparent. An infection may remain localized, or it may spread through the blood or lymphatic vessels to become systemic (bodywide). Microorganisms that live naturally in the body are not considered infections. For example, bacteria that normally live within the mouth and intestine are not infections.

Pathogen: An agent of disease. For example, Bacillus anthracis is the pathogen that causes anthrax.

Host- 1. The organism from which a parasite obtains its nutrition and/or shelter.

         2. An organism or cell culture in which a virus can replicate itself.

Reservoir of infection: Any person, animal, plant, soil or substance in which an infectious agent normally lives and multiplies. The reservoir typically harbors the infectious agent without injury to itself and serves as a source from which other individuals can be infected. The infectious agent primarily depends on the reservoir for its survival. It is from the reservoir that the infectious substance is transmitted to a human or another susceptible host.

Zoonosis: An infection that is known in nature to infect both humans and lower vertebrate animals.

Many infectious agents have the ability to infect more than one host species, making it very difficult to track. 62% of all human pathogens are classified as zoonoses. The pathogens that infect livestock are 77% zoonotic. Fifty seven of the seventy animal diseases that are considered to be of greatest importance infect multiple hosts. These multi-host pathogens are hard to control and it is important to understand the term reservoir of infection. 

Often, emerging human or wildlife diseases are assumed to be maintained in a reservoir host; but are rarely defined. The control efforts are often directed toward “Suspected reservoir populations”.  Reservoirs that harbor Ebola are still unknown, making it difficult to eradicate the disease (Hayden, et. al, 2002).

If you are interested in this topic; you can read further by looking at this article:

Haydon, D., et. al., 2002. Identifying Reservoirs of Infection: A Conceptual and Practical Challenge. Emerging Infectious Disease. Vol 8(12). 1468-1473.

Students can also search on Searchwise to find similar articles.