Advances, Challenges, and Gaps in Understanding Landscape Influences on Freshwater Systems
Dana M. Infante, Lizhu Wang, Robert M. Hughes, Kai Chen, and Bianca de Freitas Terra
Freshwater ecosystems are threatened globally, and conserving them and the organisms they support is challenged in part by the need to account for their connections to the landscape (Sala et al. 2000; Dudgeon et al. 2007; Abell et al. 2017). Natural landscape factors such as geology, topography, and climate determine the ecological potential for a given freshwater ecosystem. Anthropogenic pressures occurring near to and distant from freshwater ecosystems modify habitat and ultimately influence organisms in those systems. Hence, landscape analyses provide frameworks for understanding interactions between landscape characteristics and freshwater conditions, knowledge of how freshwaters may be limited by pressures, and a means for mitigating stressors and conserving freshwaters.
The purpose of this chapter is to describe advances in understanding how landscape influences affect freshwaters and the organisms they support that have occurred since 2006. It is not intended to be a complete review of advances in landscape-aquatic ecology since that time. Instead, we draw from the 19 chapters included in this book as well as other literature to describe progress made in four key areas first mentioned in Wang et al. (2006). These include (1) identifying meaningful spatial units for aquatic systems, (2) determining how humans modify aquatic systems, (3) measuring and understanding how factors occurring at different spatial extents influence aquatic systems, and (4) gathering landscape and aquatic data. This chapter also summarizes remaining challenges and gaps for effectively understanding linkages between landscapes and freshwaters. Finally, we summarize a set of policy recommendations originating from the preceding chapters of this volume.