Ecosystem feedbacks and cascade processes: understanding their role in the responses of Arctic and alpine ecosystems to environmental change

By P. Wookey, Rien Aerts, R. Bardgett, F. Baptist, K. Bråthen, J. H. C. Cornelissen, L. Gough, I. Hartley, D. Hopkins, S. Lavorel and 1 more. 2009

393 citations recorded by the source corpus.

Global environmental change, related to climate change and the deposition of airborne N‐containing contaminants, has already resulted in shifts in plant community composition among plant functional types in Arctic and temperate alpine regions. In this paper, we review how key ecosystem processes will be altered by these transformations, the complex biological cascades and feedbacks that might result, and some of the potential broader consequences for the earth system. Firstly, we consider how patterns of growth and allocation, and nutrient uptake, will be altered by the shifts in plant dominance. The ways in which these changes may disproportionately affect the consumer communities, and rates of decomposition, are then discussed. We show that the occurrence of a broad spectrum of plant growth forms in these regions (from cryptogams to deciduous and evergreen dwarf shrubs, graminoids and forbs), together with hypothesized low functional redundancy, will mean that shifts in plant dominance result in a complex series of biotic cascades, couplings and feedbacks which are supplemental to the direct responses of ecosystem components to the primary global change drivers. The nature of these complex interactions is highlighted using the example of the climate‐driven increase in shrub cover in low‐Arctic tundra, and the contrasting transformations in plant functional composition in mid‐latitude alpine systems. Finally, the potential effects of the transformations on ecosystem properties and processes that link with the earth system are reviewed. We conclude that the effects of global change on these ecosystems, and potential climate‐change feedbacks, cannot be predicted from simple empirical relationships between processes and driving variables. Rather, the effects of changes in species distributions and dominances on key ecosystem processes and properties must also be considered, based upon best estimates of the trajectories of key transformations, their magnitude and rates of change.

Subfields: Atmospheric Science, Ecology

View Paper: https://www.semanticscholar.org/paper/77db3bd599ee6d8f7d59172011a999e0bc25637f

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Citations in the corpus

Soil nitrogen cycling rates in low arctic shrub tundra are enhanced by litter feedbacks (2010, background): “Therefore, our results do not support the idea that shrub litter quality and canopy shading in the growing season period restrict N cycling and plant growth thereby countering positive winter feedback processes (Chapin et al. 2005; Sturm et al. 2001a; Wookey et al. 2009).”
Satellite observations of high northern latitude vegetation productivity changes between 1982 and 2008: ecological variability and regional differences (2011, background): “Understanding these changes is important because they will feed back to climate directly through their effects on atmospheric CO2 concentrations, and also indirectly by altering terrestrial energy budgets and hydrologic cycles (Chapin et al 2008, Wookey et al 2009).”
The response of Arctic vegetation to the summer climate: relation between shrub cover, NDVI, surface albedo and temperature (2011, background): “Changes in temperature, precipitation and growing season length are likely to have great effects on future vegetation development in the Arctic, resulting in ecosystem feedbacks that may lead to further climatic changes (Wookey et al 2009).”
Increased plant productivity in Alaskan tundra as a result of experimental warming of soil and permafrost (2012, background): “Warming temperatures may also bring about phenological changes and shifts in the plant community (Wookey et al. 1993, 2009; Arft et al. 1999; Aerts et al. 2004; Aerts, Cornelissen & Dorrepaal 2006) that, combined with changes in ecosystem N, may further increase the potential for warming…”
Linkages of plant traits to soil properties and the functioning of temperate grassland (2010, background): “One of the most likely impacts of global change on ecosystems is a change in plant species distributions, and therefore in the structure of the plant community (Bardgett, Freeman & Ostle 2008; Cornwell et al. 2008; Wookey et al. 2009).”
Positive feedbacks amplify rates of woody encroachment in mesic tallgrass prairie (2011, background): “…of water and nutrients, which facilitates the establishment of other shrubs and creates a positive feedback loop (Schlesinger et al. 1990, Scheffer et al. 2001, Ravi et al. 2007, Wookey et al. 2009, D’Odorico et al. 2010; see Archer et al. 1988 for mechanisms related to seed dispersal).”
Environmental factors and traits that drive plant litter decomposition do not determine home‐field advantage effects (2015, background): “Finally, our findings imply that shifts in temperature and corresponding changes in plant community composition and plant trait spectra as expected to occur under future climate change (Cornelissen et al. 2007; Wookey et al. 2009) will have strong direct effects on decomposition processes in subarct”
Large herbivores limit CO2 uptake and suppress carbon cycle responses to warming in West Greenland (2011, background): “Arctic terrestrial ecosystems have undergone substan- tial structural and functional changes in recent decades, in response to directional shifts in abiotic (Chapin et al., 1995; Clein et al., 2000; Wookey et al., 2009) and biotic drivers (Post & Pedersen, 2008; Post et al., 2009).”
Direct and indirect effects of climate change on soil microbial and soil microbial‐plant interactions: What lies ahead? (2015, background): “Climatic change is altering species distribu- tions and simultaneously impacting interactions among organisms (Wookey et al. 2009, van der Putten 2012).”
Integrating plant–soil interactions into global carbon cycle models (2009, background): “However, the interactive effects (additive, synergistic or antagonistic) of different drivers could be very important under global change (Mikkelsen et al. 2008; Tylianakis et al. 2008;Wookey et al. 2009).”
Shrub expansion in tundra ecosystems: dynamics, impacts and research priorities (2011, background): “These increases in cover and height potentially restrict the growth of other plant species by limiting light availability [6, 7, 10, 11].”