Combined effects of co‐occurring global climate changes on ecosystem responses are generally poorly understood. Here, we present results from a 2‐year field experiment in a Carex fen ecosystem on the southernmost tip of South America, where we examined the effects of solar ultraviolet B (UVB, 280–315 nm) and warming on above‐ and belowground plant production, C : N ratios, decomposition rates and earthworm population sizes. So...

As a result of stratospheric ozone depletion, more solar ultraviolet‐B radiation (UV‐B, 280–315 nm) is reaching the Earth's surface. Enhanced levels of UV‐B may, in turn, alter ecosystem processes such as decomposition. Solar UV‐B radiation could affect decomposition both indirectly, by changes in the chemical composition of leaves during growth, or directly by photochemical breakdown of litter and through changes in decompose...

Tierra del Fuego, Argentina (55°S), receives increased solar ultraviolet‐B radiation (UV‐B) as a result of Antarctic stratospheric ozone depletion. We conducted a field study to examine direct and indirect effects of solar UV‐B radiation on decomposition of Gunnera magellanica , a native perennial herb, and on the native community of decomposer organisms. In general, indirect effects of UV‐B mostly occur due to changes in the...

Stratospheric ozone depletion caused by the release of chlorofluorocarbons is most pronounced at high latitudes, especially in the Southern Hemisphere (including the so‐called ‘ozone hole’). The consequent increase in solar ultraviolet‐B radiation (UV‐B, 280–315 nm) reaching the earth's surface may cause a variety of alterations in terrestrial ecosystems. Most effects might be expected to occur above‐ground since sunlight does...

Summary A study was made of the effects of solar ultraviolet‐B radiation (UV‐B) on the growth of the dominant plant species of a shrub‐dominated ecosystem in Tierra del Fuego. This part of southern Argentina can be under the direct influence of the Antarctic ‘ozone hole’ during the austral spring and lingering ozone‐depleted air during the summer. The plant community is dominated by an evergreen shrub ( Chiliotrichum diffusum...

Stratospheric ozone depletion occurs over Tierra del Fuego, southern Argentina and Chile, in the austral spring and summer due to the precession of the Antarctic ‘ozone hole’ and the general erosion of the ozone layer. Plots receiving either near‐ambient or reduced UV‐B radiation were established using different louvered plastic film filters over Sphagnum bog and Carex fen ecosystems in October 1996. In the Sphagnum bog system...

Solar ultraviolet‐B (UV‐B) radiation penetrates plant canopies to a different degree than photosynthetically active radiation (PAR) because UV‐B is diffused to a greater degree by the atmosphere. We measured both global (total) and diffuse solar radiation in canopy gaps of a semideciduous tropical forest in Panama. Measurements were simultaneously made in the UV‐B and PAR wavebands. Compared to unobstructed measurements taken...