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Spatial and temporal changes in South African solar ultraviolet-B exposure: Implications for threatened taxa

Musil, C F; Rutherford, M C; Powrie, L W; Björn, Lars Olof LU and McDonald, D J (1999) In Ambio 28(5). p.450-456
Abstract
Spatial and temporal changes in South African solar UV-B (280-315 nm) exposure were modeled and mapped at 2.5 km2 resolution using ozone, relative humidity, cloud amount and elevation data. Computations indicated large natural gradients in UV-B exposure ranging from a 34.2% change over 14o of latitude to a 44.2% change over 16o of longitude. Modelling of future scenarios in annual UV-B exposure indicated small increases ranging from 2.5% in the year 2003 (best-case ozone depletion scenario) to 8.1% in the year 2051 (worst-case ozone-depletion scenario). Notable were substantial increases in intra-annual variability in UV-B radiation with ozone depletion. Exposure exhibits a 12% increase during late autumn (May) in the year 2003 and a 35%... (More)
Spatial and temporal changes in South African solar UV-B (280-315 nm) exposure were modeled and mapped at 2.5 km2 resolution using ozone, relative humidity, cloud amount and elevation data. Computations indicated large natural gradients in UV-B exposure ranging from a 34.2% change over 14o of latitude to a 44.2% change over 16o of longitude. Modelling of future scenarios in annual UV-B exposure indicated small increases ranging from 2.5% in the year 2003 (best-case ozone depletion scenario) to 8.1% in the year 2051 (worst-case ozone-depletion scenario). Notable were substantial increases in intra-annual variability in UV-B radiation with ozone depletion. Exposure exhibits a 12% increase during late autumn (May) in the year 2003 and a 35% increase during this season in the year 2051. Taxonomic, life form and functional attributes were analyzed in 2146 threatened (rare, endangered, vulnerable) species representing 468 genera and 103 families, and their distributions compared with modeled spatial and temporal UV-B distribution patterns. The high fractions of evergreen and succulent life forms and geophytes, present among threatened taxa, indicate a high degree of physiological resilience to increased solar UV-B stress, though some life forms, e.g. trees, appear relatively less resistant. Conceivable reductions in per capita reproductive output and overall plant fitness were indicated in some plant functional types, e.g. herbaceous annuals, which may lead to altered patterns of species coexistence, floristic composition and diversity. (Less)
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publication status
published
subject
in
Ambio
volume
28
issue
5
pages
450 - 456
publisher
Springer
external identifiers
  • scopus:0032876217
ISSN
0044-7447
language
English
LU publication?
yes
id
8d7b4a1a-20b5-4a7c-8ccd-97f067c20bd0 (old id 134414)
date added to LUP
2007-07-30 13:22:07
date last changed
2017-01-01 07:13:13
@article{8d7b4a1a-20b5-4a7c-8ccd-97f067c20bd0,
  abstract     = {Spatial and temporal changes in South African solar UV-B (280-315 nm) exposure were modeled and mapped at 2.5 km2 resolution using ozone, relative humidity, cloud amount and elevation data. Computations indicated large natural gradients in UV-B exposure ranging from a 34.2% change over 14o of latitude to a 44.2% change over 16o of longitude. Modelling of future scenarios in annual UV-B exposure indicated small increases ranging from 2.5% in the year 2003 (best-case ozone depletion scenario) to 8.1% in the year 2051 (worst-case ozone-depletion scenario). Notable were substantial increases in intra-annual variability in UV-B radiation with ozone depletion. Exposure exhibits a 12% increase during late autumn (May) in the year 2003 and a 35% increase during this season in the year 2051. Taxonomic, life form and functional attributes were analyzed in 2146 threatened (rare, endangered, vulnerable) species representing 468 genera and 103 families, and their distributions compared with modeled spatial and temporal UV-B distribution patterns. The high fractions of evergreen and succulent life forms and geophytes, present among threatened taxa, indicate a high degree of physiological resilience to increased solar UV-B stress, though some life forms, e.g. trees, appear relatively less resistant. Conceivable reductions in per capita reproductive output and overall plant fitness were indicated in some plant functional types, e.g. herbaceous annuals, which may lead to altered patterns of species coexistence, floristic composition and diversity.},
  author       = {Musil, C F and Rutherford, M C and Powrie, L W and Björn, Lars Olof and McDonald, D J},
  issn         = {0044-7447},
  language     = {eng},
  number       = {5},
  pages        = {450--456},
  publisher    = {Springer},
  series       = {Ambio},
  title        = {Spatial and temporal changes in South African solar ultraviolet-B exposure: Implications for threatened taxa},
  volume       = {28},
  year         = {1999},
}