species imbalance

https://doi.org/10.1351/goldbook.15050
Change in the species numbers or diversity in an ecosystem, or in their interactions, which results in change in ecological character and its functions and attributes.
Source:
PAC, 2009, 81, 829. (Glossary of terms used in ecotoxicology (IUPAC Recommendations 2009)) on page 948 [Terms] [Paper]