A global database and ‘state of the field’ review of research into ecosystem engineering by land animals.

1. Ecosystem engineers have been widely studied for terrestrial systems, but global trends in research encompassing the range of taxa and functions have not previously been synthesised. 2. We synthesised contemporary understanding of engineer fauna in terrestrial habitats and assessed the methods used to document patterns and processes, asking: 1.Which species act as ecosystem engineers and with whom do they interact? 2. What are the impacts of ecosystem engineers in terrestrial habitats and how are they distributed? 3. What are the primary methods used to examine engineer effects and how have these developed over time? We considered the strengths, weaknesses and gaps in knowledge related to each of these questions, and suggested a conceptual framework to delineate ‘significant impacts’ of engineering interactions for all terrestrial animals. 3. We collected peer-reviewed publications examining ecosystem engineer impacts and created a database of engineer species to assess experimental ...