Bucher Solveig Franziska, König Patrizia, Menzel Annette, Migliavacca Mirco, Ewald Jörg, Römermann Christine
Department of Plant Biodiversity Institute of Ecology and Evolution Friedrich Schiller University Jena Jena Germany.
German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig Leipzig Germany.
Ecol Evol. 2017 Dec 20;8(2):1147-1158. doi: 10.1002/ece3.3720. eCollection 2018 Jan.
Phenological responses to changing temperatures are known as "fingerprints of climate change," yet these reactions are highly species specific. To assess whether different plant characteristics are related to these species-specific responses in flowering phenology, we observed the first flowering day (FFD) of ten herbaceous species along two elevational gradients, representing temperature gradients. On the same populations, we measured traits being associated with (1) plant performance (specific leaf area), (2) leaf biochemistry (leaf C, N, P, K, and Mg content), and (3) water-use efficiency (stomatal pore area index and stable carbon isotopes concentration). We found that as elevation increased, FFD was delayed for all species with a highly species-specific rate. Populations at higher elevations needed less temperature accumulation to start flowering than populations of the same species at lower elevations. Surprisingly, traits explained a higher proportion of variance in the phenological data than elevation. Earlier flowering was associated with higher water-use efficiency, higher leaf C, and lower leaf P content. In addition to that, the intensity of shifts in FFD was related to leaf N and K. These results propose that traits have a high potential in explaining phenological variations, which even surpassed the effect of temperature changes in our study. Therefore, they have a high potential to be included in future analyses studying the effects of climate change and will help to improve predictions of vegetation changes.
物候对温度变化的响应被称为“气候变化的指纹”，然而这些反应具有高度的物种特异性。为了评估不同的植物特征是否与开花物候中这些物种特异性反应相关，我们沿着代表温度梯度的两个海拔梯度观察了十种草本植物的初花日（FFD）。在相同的种群上，我们测量了与以下方面相关的性状：（1）植物性能（比叶面积），（2）叶片生物化学（叶片碳、氮、磷、钾和镁含量），以及（3）水分利用效率（气孔面积指数和稳定碳同位素浓度）。我们发现，随着海拔升高，所有物种的初花日都以高度物种特异性的速率延迟。与低海拔的同物种种群相比，高海拔种群开始开花所需的温度积累更少。令人惊讶的是，性状在物候数据中解释的方差比例高于海拔。较早开花与较高的水分利用效率、较高的叶片碳含量和较低的叶片磷含量相关。除此之外，初花日变化的强度与叶片氮和钾有关。这些结果表明，性状在解释物候变化方面具有很大潜力，在我们的研究中甚至超过了温度变化的影响。因此，它们很有可能被纳入未来研究气候变化影响的分析中，并将有助于改进对植被变化的预测。
