Aquatic biodiversity in forests: a weak link in ecosystem services resilience

Abstract

The diversity of aquatic ecosystems is being quickly reduced on many continents, warranting a closer examination of the consequences for ecological integrity and ecosystem services. Here we describe intermediate and final ecosystem services derived from aquatic biodiversity in forests. We include a summary of the factors framing the assembly of aquatic biodiversity in forests in natural systems and how they change with a variety of natural disturbances and human-derived stressors. We consider forested aquatic ecosystems as a multi-state portfolio, with diverse assemblages and life-history strategies occurring at local scales as a consequence of a mosaic of habitat conditions and past disturbances and stressors. Maintaining this multi-state portfolio of assemblages requires a broad perspective of ecosystem structure, various functions, services, and management implications relative to contemporary stressors. Because aquatic biodiversity provides multiple ecosystem services to forests, activities that compromise aquatic ecosystems and biodiversity could be an issue for maintaining forest ecosystem integrity. We illustrate these concepts with examples of aquatic biodiversity and ecosystem services in forests of northwestern North America, also known as Northeast Pacific Rim. Encouraging management planning at broad as well as local spatial scales to recognize multi-state ecosystem Communicated by Eckehard Brockerhoff, Hervé Jactel and Ian Thompson. This is part of the special issue on 'Forest biodiversity and ecosystem services'.& Brooke E. Penaluna bepenaluna@fs.fed.us management goals has promise for maintaining valuable ecosystem services. Ultimately, integration of information from socio-ecological ecosystems will be needed to maintain ecosystem services derived directly and indirectly from forest aquatic biota.

Forest biodiversity, ecosystem functioning and the provision of ecosystem services

“…Under such circumstances, even plantations of exotic trees can provide important habitats for forest species, although attention needs to be given to management options that enhance the value for forest specialists and species of conservation concern (O'Callaghan et al 2017). The maintenance of ecosystem services provided by aquatic biota in managed forests in north-western North America is examined by Penaluna et al (2017). They highlight the complex nature of relationships between aquatic biodiversity and numerous ecosystem services and the need for better quantification and understanding of process interactions.…”

Using Natural Disturbance and Portfolio Concepts to Guide Aquatic–Riparian Ecosystem Management

“…Human actions interrupt migratory life histories of aquatic organisms through road crossings and other barriers (Dunham et al 2003;Rieman et al 2003); alter sediment production and transport regimes (Istanbulluoglu et al 2004;Goode et al 2012;Maturana et al 2014); change flow, bed scour, and temperature regimes (Marks et al 1998;Lessard and Hayes 2003;Tonina et al 2008); and alter wood loading and channel morphology (Montgomery et al 1995;Wood-Smith and Buffington 1996;Benda et al 2003;May and Gresswell 2003). Because natural disturbance initiates much of the ecosystem dynamism in aquatic-riparian ecosystems (Figure 2), emulating and (to the extent possible) allowing natural disturbance processes in management practices may lead to long-term productivity and resilience of ecosystem services (Koellner and Schmitz 2006;Penaluna et al 2016). For example, chronic supplies of fine sediment from forest roads can have a greater and longer-lasting impact on salmonid spawning habitats than an equal volume of material introduced as a sediment pulse by a naturally occurring debris flow or landslide (Maturana et al 2014).…”

“…In places where emulating natural disturbances is no longer possible (e.g., due to development), managers may have to use active restoration to return key system structures and functions to a desired level so that future natural disturbances and human actions may operate without undesired consequences (Rieman et al 2010;Penaluna et al 2016). Natural disturbances that are neither too infrequent nor too recurrent maximize species diversity (intermediate disturbance hypothesis ;Connell 1978).…”

“…The traditional management approach to meeting these responsibilities has been to create and maintain a standard set of conditions across a landscape, often targeted toward a subset of selected organisms. Emerging views of aquatic-riparian ecosystems describe them as having a range of processes and attributes that are inherently complex, nonlinear, and dynamic (Reeves et al 1995;Wallington et al 2005;Penaluna et al 2016). However, a static ecosystem perspective does not capture the dynamic nature of natural systems that is necessary to support long-term habitat complexity and species diversity (Montgomery 1999;White and Jentsch 2001;Bisson et al 2003;Hiers et al 2016).…”

“…However, a static ecosystem perspective does not capture the dynamic nature of natural systems that is necessary to support long-term habitat complexity and species diversity (Montgomery 1999;White and Jentsch 2001;Bisson et al 2003;Hiers et al 2016). Emerging views of aquatic-riparian ecosystems describe them as having a range of processes and attributes that are inherently complex, nonlinear, and dynamic (Reeves et al 1995;Wallington et al 2005;Penaluna et al 2016). In particular, habitat conditions that are currently deemed unfavorable could become high-quality habitat in the future because natural processes promote habitat change over space and time.…”