White House. Washington, D.C. White House, formerly known as the Executive Mansion (1810â1902), the official office and residence of the president of the United States at 1600 Pennsylvania Avenue N.W. in Washington, D.C. The White House and its landscaped grounds occupy 18 acres (7.2 hectares).
Quick Answer. Ecological balance is a theory stipulating that natural conditions, including numbers of various animal and plant species, remain stable on their own through variations over time.
An example of succession. Open water such as a lake or pond eventually becomes climax woodland. Hold your mouse pointer over each image for more information or for a full explanation click here. Ecological succession is the gradual process by which ecosystems change and develop over time. Nothing remains the same and habitats are constantly changing. There are two main types of succession, primary and secondary.