Fotelli Mariangela N, Rennenberg Heinz, Holst Thomas, Mayer Helmut, Geßler Arthur
Chair of Tree Physiology, Institute of Forest Botany and Tree Physiology, Albert Ludwig University of Freiburg, Georges-Köhler-Allee, Gebäude 053/054, 79110 Freiburg, Germany.
Meteorological Institute, Albert Ludwig University of Freiburg, Werderring 10, 79085 Freiburg, Germany.
New Phytol. 2003 Jul;159(1):229-244. doi: 10.1046/j.1469-8137.2003.00782.x.
• Here, the effects were assessed of local climate and canopy thinning on the carbon isotope composition (δ C) signatures of different plant groups in the understorey of a beech (Fagus sylvatica) forest in southern Germany. The relationship between δ C and environmental parameters, within different time integrals, was also studied. • δ C was analysed in different tissues of beech regeneration, and herbaceous and woody understorey vegetation, in thinned and untreated control stands differing in aspect and, hence, local climate, on three dates during the growing season. • Generally, tissues were C-depleted on the north-east, compared with the south-west aspect. Thinning had variable effects on δ C, depending on plant group and sampling date. δ C in beech leaves and roots in control stands was mostly influenced by mean soil water potential in 4- and 8-wk integrals before sampling, respectively, and in leaves, additionally, by mean radiation in a 4-wk time integral. Shoot water potential and transpiration influenced foliar δ C of beech whereas δ C in the beech wood was modulated by soil temperature integrated over a 4-wk period before sampling. Above-ground tissues of woody and herbaceous plants were C-enriched in mid-summer; their δ C was poorly related to environmental factors. • δ C of various tissues of beech regeneration appears to be indicative of recent environmental conditions within the forest understorey and, consequently, this easy-to-determine physiological parameter could be used widely to assess effects of silvicultural treatments.
• 在此，评估了德国南部山毛榉（欧洲山毛榉）林下层不同植物组的局部气候和树冠疏伐对碳同位素组成（δC）特征的影响。还研究了不同时间积分内δC与环境参数之间的关系。
• 在生长季节的三个日期，对位于不同坡向（因此局部气候不同）的疏伐林分和未处理对照林分中的山毛榉更新、草本和木本下层植被的不同组织进行了δC分析。
• 一般来说，与西南坡相比，东北坡的组织碳含量较低。疏伐对δC的影响因植物组和采样日期而异。对照林分中山毛榉叶片和根系的δC分别主要受采样前4周和8周积分期内的平均土壤水势影响，而叶片中的δC还额外受4周时间积分期内的平均辐射影响。嫩梢水势和蒸腾作用影响山毛榉叶片的δC，而山毛榉木材中的δC则受采样前4周期间土壤温度积分的调节。木本和草本植物的地上组织在仲夏时碳含量较高；它们的δC与环境因素的相关性较差。
• 山毛榉更新的各种组织的δC似乎表明了森林下层近期的环境状况，因此，这个易于测定的生理参数可广泛用于评估造林处理的效果。
