Do photoprotective pigments and antioxidants in needles of Pinus sylvestris relate to high N or water availability at field plots in a dry year?

Horn

2005

S. 107-116

3 Abb., 19 Lit. Ang.

Artikel aus einer ZeitschriftUnselbständiges Werk

200138858

Photoprotective pigments and antioxidants are widely used as stress markers in trees. We investigated these compounds in needles of mature Pinus sylvestris growing at three field plots (coded GR, KA, and LI) in Brandenburg, Germany, in a drought year (1999). The plots differ with respect to water availability and former exposure to high atmospheric N input. OR has lower water availability than KA and LI, and LI was exposed to very high atmospheric N input until 1990. Even 9 years later, LI needles still had higher needle N concentrations. Chlorophyll concentrations were lowest and carotenoid and tocopherol concentrations per mg chlorophyll were highest at GR, but similar between KA and LI. The epoxidation state of the xanthophylls was lower at OR and LI compared to KA. Ascorbate and glutathione concentrations and redox states were similar across the plots. We conclude that in this dry year needle photoprotective pigments and antioxidants were more related to low water availability (at GR) than to high N status (at LI).