Tumajer Jan, Scharnweber Tobias, Smiljanic Marko, Wilmking Martin
Institute of Botany and Landscape Ecology, University of Greifswald, Soldmannstraβe 15, 17487, Greifswald, Germany.
Department of Physical Geography and Geoecology, Faculty of Science, Charles University, Albertov 6, 12843, Prague, Czech Republic.
New Phytol. 2022 Mar;233(6):2429-2441. doi: 10.1111/nph.17952. Epub 2022 Jan 22.
Understanding the effects of temperature and moisture on radial growth is vital for assessing the impacts of climate change on carbon and water cycles. However, studies observing growth at sub-daily temporal scales remain scarce. We analysed sub-daily growth dynamics and its climatic drivers recorded by point dendrometers for 35 trees of three temperate broadleaved species during the years 2015-2020. We isolated irreversible growth driven by cambial activity from the dendrometer records. Next, we compared the intra-annual growth patterns among species and delimited their climatic optima. The growth of all species peaked at air temperatures between 12 and 16°C and vapour pressure deficit (VPD) below 0.1 kPa. Acer pseudoplatanus and Fagus sylvatica, both diffuse-porous, sustained growth under suboptimal VPD. Ring-porous Quercus robur experienced a steep decline of growth rates with reduced air humidity. This resulted in multiple irregular growth peaks of Q. robur during the year. By contrast, the growth patterns of the diffuse-porous species were always right-skewed unimodal with a peak in June between day of the year 150-170. Intra-annual growth patterns are shaped more by VPD than temperature. The different sensitivity of radial growth to VPD is responsible for unimodal growth patterns in both diffuse-porous species and multimodal growth pattern in Q. robur.
了解温度和湿度对径向生长的影响对于评估气候变化对碳和水循环的影响至关重要。然而，在亚日时间尺度上观测生长的研究仍然很少。我们分析了2015年至2020年期间35棵三种温带阔叶树种的点式测树仪记录的亚日生长动态及其气候驱动因素。我们从测树仪记录中分离出由形成层活动驱动的不可逆生长。接下来，我们比较了不同物种的年内生长模式，并划定了它们的气候适宜范围。所有物种的生长在气温12至16°C且水汽压亏缺（VPD）低于0.1 kPa时达到峰值。两种散孔材的假挪威槭和欧洲山毛榉在次优VPD条件下仍能持续生长。环孔材的欧洲栎随着空气湿度降低，生长速率急剧下降。这导致欧洲栎在一年内出现多个不规则生长峰值。相比之下，散孔材物种的生长模式总是右偏单峰型，在一年中的第150 - 170天之间的6月达到峰值。年内生长模式更多地受VPD而非温度的影响。径向生长对VPD的不同敏感性导致了散孔材物种的单峰生长模式和欧洲栎的多峰生长模式。
