Ocean warming and acidification modify top-down and bottom-up control in a tropical seagrass ecosystem

Abstract

Seagrass ecosystem is one of the most productive ecosystems in coastal waters providing numerous ecological functions and supporting a large biodiversity. However, various anthropogenic stressors including climate change are impacting these vulnerable habitats. Here, we investigated the independent and combined effects of ocean warming and ocean acidification on plant–herbivore interactions in a tropical seagrass community. Direct and indirect effects of high temperature and high pCO2 on the physiology of the tropical seagrass Thalassia hemprichii and sea urchin Tripneustes gratilla were evaluated. Productivity of seagrass was found to increase under high pCO2, while sea urchin physiology including feeding rate decreased particularly under high temperature. The present study indicated that future climate change will affect the bottom-up and top-down balance, which potentially can modify the ecosystem functions and services of tropical seagrass ecosystems.

Resilient consumers accelerate the plant decomposition in a naturally acidified seagrass ecosystem

“…Third, stressor‐driven shifts in plant productivity and physicochemical traits could modify the detritus input and decomposition rate to influence ecosystem nutrient dynamics (Cotrufo et al, 1998; Terrer et al, 2021). CO 2 enrichment and warming have shown to independently and interactively alter seagrass nutritional quality (e.g., C:N ratio) and chemical defenses (e.g., phenolic contents), but the reported effects have been variable and inconsistent, ranging from positive to negative (Arnold et al, 2012; Jiang et al, 2010; Jiménez‐Ramos et al, 2017; Listiawati & Kurihara, 2021; Martínez‐Crego et al, 2020; Scartazza et al, 2017). Likewise, the combined effects of elevated CO 2 and temperature on seagrass detrital production remain insufficiently understood.…”

“…rate to influence ecosystem nutrient dynamics(Cotrufo et al, 1998;Terrer et al, 2021). CO 2 enrichment and warming have shown to independently and interactively alter seagrass nutritional quality (e.g., C:N ratio) and chemical defenses (e.g., phenolic contents), but the reported effects have been variable and inconsistent, ranging from positive to negative(Arnold et al, 2012;Jiang et al, 2010;Jiménez-Ramos et al, 2017;Listiawati & Kurihara, 2021; …”

Emergent competition shapes the ecological properties of multi-trophic ecosystems

“…Historically, it was assumed that ecosystems could not simultaneously exhibit both top-down and bottom-up control [37,43,44]. However, recent evidence -such as the impact of overfishing on aquatic ecosystems -has overturned this view leading to a consensus that most ecosystems are impacted by both types of control and that their relative importance can shift over time [8,[45][46][47][48]. Building on these ideas, recent theoretical works suggest that ecosystems can shift between bottom-up and top-down control dominated regimes as one varies model parameters [9,[49][50][51].…”

Differential effects of ocean acidification and warming on biological functioning of a predator and prey species may alter future trophic interactions

“…Increasingly, their interaction (i.e. ocean acidification and warming (OAW)) has been shown to have wide-ranging consequences to the biological functioning of organisms including changes to physiology (Lemasson et al, 2018;Li et al, 2015), morphology (Knights et al, 2020), and behaviour (Manríquez et al, 2021) resulting in changes to population and community structure (Lemasson et al, 2018;Manríquez et al, 2021), inter-and intra-species interactions (Sadler et al, 2018), and the provision of ecosystem services (Listiawati and Kurihara, 2021).…”