| Autor: |
Edith B. Allen, Patrick J. Temple, Andrzej Bytnerowicz, Michael J. Arbaugh, Abby G. Sirulnik, Leela E. Rao |
| Jazyk: |
angličtina |
| Rok vydání: |
2007 |
| Předmět: |
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| Zdroj: |
The Scientific World Journal, Vol 7, Pp 247-263 (2007) |
| Druh dokumentu: |
article |
| ISSN: |
1537-744X |
| DOI: |
10.1100/tsw.2007.72 |
| Popis: |
The forests of the San Bernardino Mountains have been subject to ozone and nitrogen (N) deposition for some 60 years. Much work has been done to assess the impacts of these pollutants on trees, but little is known about how the diverse understory flora has fared. Understory vegetation has declined in diversity in response to elevated N in the eastern U.S. and Europe. Six sites along an ozone and N deposition gradient that had been part of a long-term study on response of plants to air pollution beginning in 1973 were resampled in 2003. Historic ozone data and leaf injury scores confirmed the gradient. Present-day ozone levels were almost half of these, and recent atmospheric N pollution concentrations confirmed the continued air pollution gradient. Both total and extractable soil N were higher in sites on the western end of the gradient closer to the urban source of pollution, pH was lower, and soil carbon (C) and litter were higher. The gradient also had decreasing precipitation and increasing elevation from west to east. However, the dominant tree species were the same across the gradient. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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