Ecological Restoration 

Over the past 50 years, humans have changed ecosystems more rapidly and extensively than in any comparable period of time in human history, largely to meet rapidly growing demands for food, fresh water, timber, fiber and fuel. This has resulted in a substantial and largely irreversible loss in the diversity of life on Earth.

Millennium Ecosystem Assessment. 16 July, 2009. http://www.maweb.org/en/Index.aspx

This photo was taken in McLean County, Illinois at a prarieland restoration project supported by the ParkLands Foundation.

Creative Commons Flickr. 16 July 2009. http://www.flickr.com/photos/lindenbaum/331396105/

Ecological restoration is an intentional activity that initiates or accelerates the recovery of an ecosystem with respect to its health, integrity and sustainability. Frequently, the ecosystem that requires restoration has been degraded, damaged, transformed or entirely destroyed as the direct or indirect result of human activities. In some cases, these impacts to ecosystems have been caused or aggravated by natural agencies such as wildfire, floods, storms, or volcanic eruption, to the point at which the ecosystem cannot recover its predisturbance state or its historic developmental trajectory. -Society for Ecological Restoration

Ecological restoration is the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed. -The Society for Ecolological Restoration International, Science and Policy Working Group, 2002

Ecological restoration is the process of returning polluted or otherwise disturbed ecosystems to a close approximation of their condition prior to contamination. Restoration is a broad term that encompasses a number of interrelated activities, including the reconstruction of antecedent physical conditions, chemical adjustment of the soil and water, and biological manipulation which includes the reintroduction of native flora and fauna. -United States Environmental Protection Agency

There are many Library of Congress subject headings which you may want to use to look for books and journals in the online catalog. You can divide many of these subject headings further by geography and/or a more specific subject (e.g. Restoration ecology--Illinois or Grassland resoration--Case Studies).

Applied ecology     
Biocultural restoration    
Dynamic ecosystems    
Ecological genetics    
Ecological response    
Ecosystem dynamics    
Ecosystem management    
Ecosystem recovery    
Ecosystem repair [and healing]    
Ecosystem services
Environmental restoration
Landscape management
Reforestation
Rehabilitation ecology
Restoration constraints
Restoration ecology
Restoration failure
Restoration success