Hildrew, A., and Giller, P. (2023). The Biology and Ecology of Streams and Rivers. Oxford University Press: Oxford. ISBN: 978-0198516101 (Hardcover) 466 p. € 124.50

Abstract

In their book “The Biology and Ecology of Streams and Rivers,” Alan Hildrew and Paul Giller, two renowned senior professors and stream ecologists, summarize the current knowledge on lotic ecosystems from an ecologists' perspective. From the preface, the authors' sincere passion for running water systems is obvious. They write from an engaged and motivated perspective, while still retaining scientific rigor and objectivity. Thanks to the two authors' extensive experience in the field spanning multiple decades of running water research, the overview given throughout the textbook is comprehensive. Younger audiences may prefer a less extensive background on the historical development of some fields and ideas, but in the end, the current state of the field always emerges, even from some of the science history detours that the authors may take. As the authors are both ecologists, the focus of this book is very much on the organisms within lotic ecosystems, and the physico-chemical characteristics are presented more as a background setting to the book's main players: the living components, in particular, animal life in streams and rivers.

In the initial two chapters, Hildrew and Giller introduce streams and rivers as ecological systems and explain how the physico-chemical habitat conditions set the scene (the “habitat templet”) for the organisms and their interactions. In the third chapter, they give an overview of the diversity of organismic life in streams and rivers, illustrated with some information boxes with details on specific organisms. As a result, this chapter appears a bit too long for a mere overview, but too short for a comprehensive coverage. It is quite obvious that the authors' focus is mostly on animals, which are covered in much more detail than microbial life, such as bacteria, algae, and aquatic fungi, even though the crucial role of these microbial organisms in the functioning of running water systems is well acknowledged. Reflecting the bias in the current literature, the overview of stream and river biota is almost exclusively focused on European (and some North American) taxa.

Chapters 4–7 focus on organisms' adaptations to running water habitats and the consequences of these adaptations for ecological interactions within stream and river populations, communities, and food webs. These chapters are written exceptionally well, and it is obvious that the authors' main expertise and passion lie in these fields. Chapter 4 discusses the physiological ecology of running water organisms and the traits related to their adaptations, while chapters 5 and 6 apply general concepts from population and community ecology to the specific habitats and organisms found in streams and rivers, and chapter 7 deals with species interactions with an almost exclusive focus on trophic interactions and food webs.

Chapters 8 and 9 then change perspective from the organisms to the energy and nutrient cycles and processes in streams and rivers. In most similar textbooks, these chapters on the turnover of matter and energy would have preceded those with a focus on organisms. Nevertheless, they give a brief, but thorough and up-to-date overview of this field. This is particularly helpful for readers who are new to the field to understand the importance of quantifying ecosystem functions related to metabolism, nutrient, and carbon/energy cycles. In addition to considering processes within lotic ecosystems, also their interaction with the surrounding landscape and global matter cycles are addressed.

The final (10th) chapter then sets out “new horizons” in the ecology of streams and rivers. Here, the authors summarize the current pressures and problems on global running water systems—from the prevalent freshwater biodiversity crisis, to invasive species, emerging contaminants, and global change processes. While none of these issues can obviously be dealt with exhaustively, this chapter gives a concise yet full overview of the issues that stream and river ecosystems and scientists interested in these ecosystems' health have to deal with. The chapter is nicely complemented with a section on the ecological assessment of running waters and the new developments (e.g., DNA-based assessment methods) that may shape the future evaluation of the status and health of streams and rivers.

This book is certainly a useful resource for aquatic ecologists in general and stream and river researchers in particular. It gives an excellent overview of relevant ideas and concepts of modern running water ecology. For direct use in undergraduate teaching, the book would benefit from highlighting important keywords and definitions, as is done in other books via boldface printing of key terms or insert boxes explaining specific concepts. The insert boxes present in Hildrew's and Giller's book are written by a range of guest authors. While all of them give in-depth information on specific topics, they vary greatly in their writing styles and level of complexity. Some of the boxes appear as rather anecdotical excursions on particular organisms, while others give great insight into relevant concepts. Nevertheless, almost all of them are worth a read. The major weakness of this book is the extremely variable and sometimes quite poor quality of the figures and illustrations. Rather than designing new figures with consistent formatting, Hildrew and Giller largely rely on figures adapted from primary literature sources. This makes their look somewhat inconsistent, both graphically and didactically. Furthermore, a lot of photographs are used where drawings may have been clearer in conveying the message.

So, for whom is this the right book? It is definitely a great resource for graduate students and scientists working on the ecology of streams and rivers, and probably also for practitioners involved in the management of lotic systems. It would benefit from a clearer didactical structure and, in particular, better figures if used as a textbook for undergraduate teaching, though. But this book's appeal goes wide beyond the stream and river ecology communities. Also, for terrestrial ecologists, lake limnologists, or oceanographers who want to have an in-depth overview of running water systems, this book is a fantastic resource and sure to find a broad readership.