Biotechnical Faculty, Agronomy Department, University of Ljubljana, Ljubljana, Slovenia.
Int J Biometeorol. 2012 Jul;56(4):681-94. doi: 10.1007/s00484-011-0469-7. Epub 2011 Jul 23.
Knowledge of plant-weather relationships can improve crop management, resulting in higher quality and more stable crop yields. The annual timing of spring phenophases in mid-latitudes is largely a response to temperature, and reflects the thermal conditions of previous months. The effect of air temperature on the variability of hazelnut (Corylus avellana L.) phenophases (leafing, flowering) was investigated. Meteorological and phenological data for five cultivars were analysed over the periods 1969-1979 (P1) and 1994-2007 (P2) in Maribor, Slovenia. Phenological data series were correlated strongly to the temperature of the preceding months (R(2): 0.64-0.98) and better correlated to daily maximum and mean temperatures than to daily minimum temperatures. About 75% of phenophases displayed a tendency towards earlier appearance and a shorter flowering duration during P2, which could be explained by the significant temperature changes (+0.3°C/decade) from December to April between 1969 and 2007. An increase in air temperature of 1°C caused an acceleration in leafing by 2.5-3.9 days, with flowering showing higher sensitivity since a 1°C increase promoted male flowering by 7.0-8.8 days and female flowering by 6.3-8.9 days. The average rate of phenological change per degree of warming (days earlier per +1°C) did not differ significantly between P1 and P2. An estimation of chilling accumulation under field conditions during 1993-2009, between 1 November and 28 February, showed that all four of these months contributed approximately similar amounts of accumulated chilling units. The growing degree days (GDD) to flowering were calculated by an estimated base temperature of 2°C and 1 January as a starting date, given the most accurate calculations. In general, thermal requirements were greater in P2 than in P1, although this difference was not significant. Longer-time series data extended to other agricultural and wild plants would be helpful in tracking possible future changes in phenological responses to local climate.
对植物-气象关系的了解可以改善作物管理，从而提高作物的质量和产量稳定性。中纬度地区春季物候期的年度时间安排在很大程度上是对温度的反应，反映了前几个月的热条件。本研究调查了空气温度对榛树（Corylus avellana L.）物候期（展叶、开花）变异性的影响。在斯洛文尼亚马里博尔，分析了五个品种在 1969-1979 年（P1）和 1994-2007 年（P2）期间的气象和物候数据。物候数据系列与前几个月的温度密切相关（R2：0.64-0.98），与日最高温和日平均温度的相关性优于与日最低温度的相关性。在 P2 期间，约 75%的物候期表现出更早出现和开花持续时间更短的趋势，这可以用 1969 年至 2007 年 12 月至 4 月期间的温度变化（+0.3°C/十年）来解释。空气温度升高 1°C 会导致展叶加速 2.5-3.9 天，开花期的敏感性更高，因为温度升高 1°C 会使雄花提前 7.0-8.8 天，雌花提前 6.3-8.9 天。每升温 1°C 的物候变化率（每 +1°C 提前的天数）在 P1 和 P2 之间没有显著差异。根据最准确的计算，在 1993 年至 2009 年 11 月 1 日至 2 月 28 日期间，对田间条件下的冷积累进行了估算，结果表明这四个月的积累冷量大致相同。以估计的基础温度 2°C 和 1 月 1 日为起始日期，计算了开花的生长度日（GDD）。一般来说，P2 时期的热需求大于 P1 时期，尽管这种差异并不显著。延长时间序列数据并扩展到其他农业和野生植物，将有助于跟踪未来植物物候对当地气候的反应可能发生的变化。
