Beyond sticks and stones: Integrating physical and ecological conditions into watershed restoration assessments using a food web modeling approach

Influence of riparian thinning on trophic pathways supporting stream food webs in forested watersheds

“…Part of this variation in responses could be due to conditions unique to the context of the study watersheds such as low nutrient concentrations that potentially limited primary production (Ambrose et al, 2004; McIntyre et al, 2018; Warren et al, 2017) or the importance of terrestrial invertebrate subsidies supporting top predators (Li et al, 2016; Nakano & Murakami, 2001; Romero et al, 2005). Given that stream networks exhibit extensive spatial heterogeneity within and among systems, it is not surprising to see different responses among locations (Whitney et al, 2020). Future research could synthesize findings of recent studies to further explore the environmental drivers leading to context dependency and variation in food web responses.…”

“…Management goals that focus on the productivity of target species such as salmonid fishes can be misleading (Bellmore et al, 2017; Whitney et al, 2020), as target species are part of complex ecological networks that require an understanding of species interactions and the trophic processes supporting them (Bascompte, 2010; Naman et al, 2022). Additionally, inherent spatial and temporal variation in environmental conditions and food web structure across stream networks can lead to context dependency in biological responses (Power & Dietrich, 2002; Whitney et al, 2020). As a result, a food web perspective that explicitly considers the trophic dynamics and structure of ecological networks provides a more holistic understanding of stream ecosystems and can more effectively address the underlying mechanisms driving whether riparian thinning enhances aquatic productivity in forested streams (Bascompte, 2010; Bellmore et al, 2017; Benjamin et al, 2022; Naiman et al, 2012; Naman et al, 2022).…”

“…Uncertainty in the outcomes of riparian forest management for aquatic systems can be partially attributed to the complexity of stream–riparian systems (Baxter et al, 2005; Gregory et al, 1991; Naiman et al, 2010; Nakano & Murakami, 2001): Responses depend on and can be mediated by the food web dynamics that link streams and riparian forests (Bascompte, 2010; Power & Dietrich, 2002; Whitney et al, 2020; Wootton, 2012). Management goals that focus on the productivity of target species such as salmonid fishes can be misleading (Bellmore et al, 2017; Whitney et al, 2020), as target species are part of complex ecological networks that require an understanding of species interactions and the trophic processes supporting them (Bascompte, 2010; Naman et al, 2022). Additionally, inherent spatial and temporal variation in environmental conditions and food web structure across stream networks can lead to context dependency in biological responses (Power & Dietrich, 2002; Whitney et al, 2020).…”

Food web perspectives and methods for riverine fish conservation

“…Food web simulation models can be used to explore how river ecosystems might respond to a variety of management actions, from direct manipulations of the food web (e.g., salmon carcass addition), to alterations of the physical template upon which food webs emerge (Box 3). For example, Bellmore et al (2017) and Whitney et al (2020), used a food web model to illustrate how the structure of river food webs, specifically the presence of invasive species, can mediate responses to restoration across a river network. A strength of these models is their ability to generate testable hypotheses, which in turn can support decision making and management experiments within an adaptive management context.…”

“…Interested readers should therefore consult the references highlighted in each section for further details. In addition to these key articles, user friendly software for tackling these analyses is increasingly available; for instance, there are free open‐source programs and packages to implement bioenergetics analysis (Deslauriers et al, 2017; Naman et al, 2020), ecological community description (Hudson et al, 2013; Permado, 2015), diet composition using stable isotopes (Stock et al, 2018), and whole food web simulations (Whitney et al, 2020). We encourage interested readers to investigate these tools and their documentation, which are rapidly increasing the accessibility of food web approaches.…”