This compendium is the first systematic study of the broad spectrum of documents stored in the State Archives of Lower Saxony pertaining to matters of the environment. Based on selected parts thereof, the authors present the most important files and maps from over 160 environmental fields in Lower Saxony. The volume is conceived as a thematic guidebook and offers a quick perspective of the types and volume of archival materials available from the 18th to the 20th century concerning in the main matters of environmental interest in Lower Saxony. With this volume the reader is put in the position to retrieve pertinent information about the respective environmental research, to recognize research gaps and to continue or suggest further studies.