Flow-ecology modelling

Riparian plant networks under different flow regimes futures (Tonkin et. al, 2018)

River ecosystems are governed by patterns of temporal variation in river flows. Two major stressors threaten river flows and the integrity of river ecosystems globally. Dams continue to heavily modify river flow regimes (sequences of floods and drought), and climate change is pushing flow regimes beyond their historical envelope of variability. These alterations to river flows can severely affect freshwater ecosystems. We develop mechanistic models that link population dynamics directly with river flow regimes to understand both population and whole-community (e.g. fish, invertebrates, riparian plants) responses to global change. By explicitly modelling the biology underpinning the distribution of species, rather than correlating the presence of species with particular conditions, mechanistic, or process-based, models offer a greater capacity to forecast species responses to novel combinations of environmental conditions. These models not only enable us to understand and forecast the potential effects of hydro-climatic change on freshwater and riparian biodiversity, but also to inform managers of how to better allocate water to protect downstream biodiversity. For instance, we ask questions of the consequences of designer or environmental flows on entire ecosystems, including the tradeoffs associated with designing flows for a particular sector of the ecosystem. Our research to date emphasises the importance of maintaining aspects of the natural flow regime into a future world, but particularly important is the maintenance of floods to overcome the negative long-term consequences of flow modification on riverine ecosystems.

Avatar
Jonathan Tonkin
Senior Lecturer & Rutherford Discovery Fellow

Publications

Prepare river ecosystems for an uncertain future

As the climate warms, we can’t restore waterways to pristine condition, but models can predict potential changes, argue Jonathan D. …

Increasing drought favors nonnative fishes in a dryland river: Evidence from a multispecies demographic model

Understanding how novel biological assemblages are structured in relation to dynamic environmental regimes remains a central challenge …

Flow regime alteration degrades ecological networks in riparian ecosystems

Riverine ecosystems are governed by patterns of temporal variation in river flows. This dynamism will change due to climate change and …

High mortality and enhanced recovery: Modelling the countervailing effects of disturbance on population dynamics

Disturbances cause high mortality in populations while simultaneously enhancing population growth by improving habitats. These …

Linking river flow regimes to riparian plant guilds: A community-wide modeling approach

Modeling riparian plant dynamics along rivers is complicated by the fact that plants have different edaphic and hydrologic requirements …