Abstract
Atmospheric CO2 concentration has increased by 25% over the preindustrial level. A parallel increase in C concentration and decreases in N concentration and δ13C of plants grown throughout this century have been observed in plant specimens stored in herbaria. We tested our previous results in a study of 12 more species collected in the western Mediterranean throughout this century (1920-1931), 1945-1955, and 1985-1990) and tree rings of Quercus pubescens from the same area. These changes were accompanied by apparent increases in condensed tannin concentration. A decreasing trend in δ15N both in herbarium material and tree rings was also found, indicating that ecosystems might cope with higher plant N demand by decreasing N losses and increasing N fixation and mineralization. These results may contribute to a better understanding of the effects of global change on carbon and nitrogen cycling.
Original language | English |
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Pages (from-to) | 69-73 |
Journal | Oecologia |
Volume | 109 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1 Dec 1996 |
Keywords
- Atmospheric CO concentration 2
- Herbarium specimens
- Nitrogen
- δ C 13
- δ N 15