Ecological Processes Handbook, Luca Palmeri, Alberto Barausse, Sven Erik Jørgensen. CRC Press, 2014.

Overview of the different ecological processes acting in ecosystems. For each process, a clear, detailed but not too lengthy definition is provided along with some practical examples, the main mathematical models which have been used to describe the process, and a description of the key interconnections with other ecological processes.

Encyclopedia of Ecology & Environmental Management, editor-in-chief, Peter Calow. Blackwell Science,1998.

One-volume guide to ecology, with 3,000 definitions covering the entire spectrum of pure and applied ecological research, and over 250 substantive entries on major topics;

Environmental Microbiology: Methods and Protocols, edited by Ian T. Paulsen, Andrew J. Holmes. Humana Press, 2014.

Presents molecular mechanisms for investigating microbial communities and their biological activities. The first section looks at methods involved in sampling environmental microorganisms, the second profiles different methods for investigating the diversity and composition of microbial communities, the third focuses on techniques for analyzing biological activities in situ, and the final section examines high throughput 'omics' approaches for the characterization of environmental microbial communities.

Encyclopedia of Theoretical Ecology edited by Alan Hastings, Louis J. Gross. Berkeley : University of California Press, 2012 .

This major reference is an overview of the current state of theoretical ecology through a series of topical entries centered on both ecological and statistical themes. Coverage ranges across scales, from the physiological, to populations, landscapes, and ecosystems.

Introduction to the Modelling of Marine Ecosystems, by W. Fennel and T. Neumann. Elsevier, 2004.

Comprehensive introduction to the development of models of marine ecosystems.

Oxford Handbook of Environmental Ethics, edited by Stephen M. Gardiner and Allen Thompson. Oxford University Press, 2015.

Forty-five essays written by leading experts that range over a broad variety of issues, concepts, and perspectives related to environmental ethics.