Global-change drivers of ecosystem functioning modulated by natural variability and saturating responses

Abstract. In order to detect shifts in community structure and function associated with global change, the natural background fluctuation in these traits must be known. In a 6 yr study we characterized the composition of young benthic communities at 7 sites along the 300 km coast of the Kiel and Lübeck bights in the German Baltic Sea and we quantified their interannual variability of taxonomic and functional composition. Along the salinity gradient from NW to SE, the relative abundance of primary producers decreased while that of heterotrophs increased. Along the same gradient, annual productivity tended to increase. Taxonomic and functional richness were higher in Kiel Bight as compared to Lübeck Bight. With increasing species richness functional group richness showed saturation indicating an increasing functional redundancy in species rich communities. While taxonomic fluctuations between years were substantial, functionality of the communities seem preserved in most cases. Environmental conditions potentially driving these fluctuations are winter temperatures and current regimes. We tentatively define a confidence range of natural variability in taxonomic and functional composition a departure from which might help identifying an ongoing regime shift driven by global change. In addition, we propose to use RELATE, a statistical procedure in the PRIMER (Plymouth Routines in Multivariate Ecological Research) package to distinguish directional shifts in time ("signal") from natural temporal fluctuations ("noise").

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Impacts of Global Change on Composition of Arctic Communities: Implications for Ecosystem Functioning

Global Change and Arctic Terrestrial Ecosystems - Ecological Studies ◽

10.1007/978-1-4612-2240-8_12 ◽

1997 ◽

pp. 221-228 ◽

Cited By ~ 6

Author(s):

F. Stuart Chapin ◽

Sarah E. Hobbie ◽

Gaius R. Shaver

Keyword(s):

Global Change ◽

Ecosystem Functioning ◽

Arctic Communities

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Non-linear response of Mediterranean ecosystem to interaction of drought and plant invasion

10.5194/egusphere-egu21-1518 ◽

2021 ◽

Author(s):

Simon Haberstroh ◽

Maria C. Caldeira ◽

Raquel Lobo-do-Vale ◽

Joana I. Martins ◽

Julia Moemken ◽

...

Keyword(s):

Global Change ◽

Ecosystem Functioning ◽

Linear Response ◽

Plant Invasion ◽

Terrestrial Ecosystems ◽

Cork Oak ◽

Mediterranean Ecosystem ◽

Tree Transpiration ◽

Non Linear ◽

The Impact

The impact of interacting global change stressors on terrestrial ecosystems is hard to predict due to non-linear, amplifying, neutral or even buffering interaction effects. We investigated the effects of drought and plant invasion on Mediterranean cork oak (Quercus suber L.) ecosystem functioning and recovery with a combined rain exclusion (30-45 % reduction) and shrub (Cistus ladanifer L.) invasion experiment. As key parameter, we determined tree, shrub and ecosystem transpiration in four treatments: 1) cork oak control stands, 2) cork oaks with rain exclusion, 3) cork oaks invaded by shrubs and 4) cork oaks with rain exclusion and shrub invasion. Rain exclusion and plant invasion led to moderate, but neutral reductions of tree transpiration of 18 % (compared to control) during the mild summer drought in 2018. In 2019, the rain exclusion simulated the second driest year since 1950 for Southwestern (SW) Iberia. The interaction effect of drought and plant invasion was strongly amplifying, reducing tree transpiration by 47 %. Legacy effects on shrubs under the rain exclusion treatment led to a non-linear response during recovery from the severe drought in 2019. Invaded trees showed a delayed transpiration recovery (-51 % vs. control) due to strong competition with shrubs, while invaded trees with rain exclusion recovered to 75 % of the control. This buffering interaction response was caused by a weaker competition from drought-stressed shrubs. Given the projected increase in the frequency, intensity and duration of drought, an increasing non-linear impact on Mediterranean cork oak ecosystems is expected. Our results demonstrate that abiotic stressors modulate biotic interactions thereby impacting ecosystem functioning in a highly dynamic manner. Further efforts are thus needed to model and manage the impact of interacting global change stressors on terrestrial ecosystems.

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Biodiversity and ecosystem functioning in terrestrial habitats of Antarctica

Antarctic Science ◽

10.1017/s0954102005002944 ◽

2005 ◽

Vol 17 (4) ◽

pp. 523-531 ◽

Cited By ~ 35

Author(s):

DIANA H. WALL

Keyword(s):

Global Change ◽

Ecosystem Functioning ◽

Ecosystem Processes ◽

Global Changes ◽

Biodiversity And Ecosystem Functioning ◽

Soil Ecosystems ◽

Terrestrial Habitats ◽

Terrestrial Biodiversity ◽

The Impact ◽

Continental Interior

Are we failing to acknowledge the impact of global changes (e.g. UVB, invasive species, climate, land use, atmosphere) on the terrestrial biodiversity and ecosystem processes of Antarctica? Antarctica is considered a pristine environment and has low terrestrial species diversity and trophic complexity, and yet while scientifically possible, we still do not know the number of species, where they are, or how their influence on ecosystem processes (e.g. nutrient cycling, carbon flux, decomposition, feedbacks to climate, hydrology) will be affected by multiple global changes. Increased recognition of human dependence on services provided by biodiversity and ecosystem functioning combined with documented impacts of global change already occurring on Antarctic soil ecosystems, increases the urgency to expand investigations regionally in Antarctica. We cannot measure the effects of global change or sustainably manage Antarctica's future if we underestimate the contribution of soil communities. Evidence indicates habitats of rocky moraines, soils and cyroconite holes of glaciers in the continental interior may host not only microbes, but also a complexity of algae and invertebrates. Scientists of many disciplines, together, need to assess the benefits humans derive from Antarctic terrestrial biodiversity and ecosystem processes, how these will be affected by global change, and link their findings to the rest of the world.

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Marine archaea and archaeal viruses under global change

F1000Research ◽

10.12688/f1000research.11404.1 ◽

2017 ◽

Vol 6 ◽

pp. 1241 ◽

Cited By ~ 7

Author(s):

Roberto Danovaro ◽

Eugenio Rastelli ◽

Cinzia Corinaldesi ◽

Michael Tangherlini ◽

Antonio Dell'Anno

Keyword(s):

Global Change ◽

Food Web ◽

Ecosystem Functioning ◽

Biogeochemical Cycles ◽

Structure And Function ◽

Food Web Structure ◽

Web Structure ◽

Archaeal Viruses ◽

And Function ◽

Marine Archaea

Global change is altering oceanic temperature, salinity, pH, and oxygen concentration, directly and indirectly influencing marine microbial food web structure and function. As microbes represent >90% of the ocean’s biomass and are major drivers of biogeochemical cycles, understanding their responses to such changes is fundamental for predicting the consequences of global change on ecosystem functioning. Recent findings indicate that marine archaea and archaeal viruses are active and relevant components of marine microbial assemblages, far more abundant and diverse than was previously thought. Further research is urgently needed to better understand the impacts of global change on virus–archaea dynamics and how archaea and their viruses can interactively influence the ocean’s feedbacks on global change.

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For flux’s sake: General considerations for energy-flux calculations in ecological communities

10.22541/au.161407278.80952854/v1 ◽

2021 ◽

Author(s):

Malte Jochum ◽

Andrew Barnes ◽

Ulrich Brose ◽

Benoit Gauzens ◽

Marie Sünnemann ◽

...

Keyword(s):

Global Change ◽

Food Web ◽

Energy Flux ◽

Ecosystem Functioning ◽

Theoretical Background ◽

Ecological Communities ◽

Ecological Research ◽

Trophic Networks ◽

Community Data ◽

Food Web Theory

Global change alters ecological communities with consequences for ecosystem processes. Such processes and functions are a central aspect of ecological research and vital to understanding and mitigating the consequences of global change, but also those of other drivers of change in organism communities. In this context, the concept of energy flux through trophic networks integrates food-web theory and biodiversity-ecosystem functioning theory and connects biodiversity to multitrophic ecosystem functioning. As such, the energy flux approach is a strikingly effective tool to answer central questions in ecology and global-change research. This might seem straight forward, given that the theoretical background and software to efficiently calculate energy flux are readily available. However, the implementation of such calculations is not always straight forward, especially for those who are new to the topic and not familiar with concepts central to this line of research, such as food-web theory or metabolic theory. To facilitate wider use of energy flux in ecological research, we thus provide a guide to adopting energy-flux calculations for people new to the method, struggling with its implementation, or simply looking for background reading, important resources, and standard solutions to the problems everyone faces when starting to quantify energy fluxes for their community data. First, we introduce energy flux and its use in community and ecosystem ecology. Then, we provide a comprehensive explanation of the single steps towards calculating energy flux for community data. Finally, we discuss remaining challenges and exciting research frontiers for future energy-flux research.

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