Current and future impacts of ultraviolet radiation on the terrestrial carbon balance

Abstract

One of the most documented effects of human activity on our environment is the reduction of stratospheric ozone resulting in an increase of biologically harmful ultraviolet (UV) radiation. In a less predictable manner, UV radiation incident at the surface of the earth is expected to be further modified in the future as a result of altered cloud condition, atmospheric aerosol concentration, and snow cover. Although UV radiation comprises only a small fraction of the total solar radiation that is incident at the earth's surface, it has the greatest energy per unit wavelength and, thus, the greatest potential to damage the biosphere. Recent investigations have highlighted numerous ways that UV radiation could potentially affect a variety of ecological processes, including nutrient cycling and the terrestrial carbon cycle. The objectives of the following literature review are to summarize and synthesize the available information relevant to the effects of UV radiation and other climate change factors on the terrestrial carbon balance in an effort to highlight current gaps in knowledge and future research directions for UV radiation research.

Mind the gap: non‐biological processes contributing to soil CO2 efflux

“…Many studies reporting soil CO 2 efflux rates in several biomes, including temperate, boreal, tropical, Arctic and deserts have been published. This intense research has prompted excellent review summarizing methods (Kuzyakov, ; Subke et al ., ; Bruggemann et al ., ), processes (Smith et al ., ; Kuzyakov & Gavrichkova, ; Kim et al ., ), estimates for different biomes (Bond‐Lamberty & Thomson, ) and current challenges (Vargas et al ., ). Apart from evidencing great progress as well as limited understanding of the biological processes involved in soil respiration (Vargas et al ., ), non‐biological processes contributing to soil CO 2 efflux have not been considered in any of these synthesis papers.…”

Direct and Indirect Effects of UV-B Exposure on Litter Decomposition: A Meta-Analysis

“…Recent research has highlighted numerous ways which UV-B could influence ecological processes, including plant litter decomposition and nutrient release [2,3]. Litter decomposition plays a key role in terrestrial carbon (C) and nitrogen (N) cycling [4,5].…”

Above‐ and below‐ground responses of Calamagrostis purpurea to UV‐B radiation and elevated CO2 under phosphorus limitation

“…Depletion in stratospheric ozone and climate change factors may also affect levels of UV radiation reaching the ground surface (McKenzie et al 2011). The effects of UV‐B radiation on plant physiology are widely reported, and include damage to DNA and proteins (Qaderi and Reid 2005, Newsham and Robinson 2009), due to the high absorption affinity of these macromolecules within the UV‐B wavelength range, which in turn can lead to photosynthetic inhibition (Smith et al 2009). Negative effects of elevated UV‐B radiation on leaf area, shoot production, fine root production and root exudation have also been found (Tevini and Teramura 1989, Rinnan et al 2006, Yang et al 2008).…”

“…Prediction of future UV‐B levels is difficult due to uncertainties about cloud cover and stratospheric ozone levels. The impacts of global warming on these factors are also unclear, as is the effect of remaining ozone‐depleting compounds (Smith et al 2009, McKenzie et al 2011). Any changes in UV‐B radiation will occur alongside other atmospheric trends such as increased atmospheric CO 2 , so it is important to consider interactions between these factors, particularly as CO 2 may modify UV‐B effects (Smith et al 2009).…”