Development models are used to quantify the dynamics and rate of initial development, the seedling phase duration, and global warming impacts on forest species. Such models relate the physiological age of the plant, through air temperature functions, to its morphological appearance, given by the cumulative leaf number on the main stem. Despite their potential, studies on initial development dynamics are still scarce, especially for native forest species. Thus, this study calibrated and evaluated the performance of two development models—Phyllochron and Wang and Engel—in estimating the cumulative leaf number and seedling phase duration of two Brazilian native forest species—Cybistax antisyphilitica (Mart.) Mart. (Bignoniaceae) and Platycyamus regnellii Benth. (Fabaceae). Cumulative leaf number and seedling phase duration data from outdoor experiments carried out during the 2017 and 2018 growing seasons with 12 sowing dates in Itajubá, Minas Gerais, Brazil, were used. These experiments provided a rich dataset for calibrating and evaluating the Phyllochron and Wang and Engel development models. Both development models were capable of predicting cumulative leaf number with low and acceptable errors for both species and produced less accurate estimates for seedling phase duration. For C. antisyphilitica, both models were remarkably similar in estimating cumulative leaf number and seedling phase duration, with a root-mean-square error of 3.3 leaves and 25 days, respectively. For P. regnellii, the Wang and Engel model was slightly better than the Phyllochron, with an error of fewer than 2.06 leaves and 13.1 days. Using the coefficients calibrated in this study and, preferably, the Wang and Engel model, it is possible to project the development of both forest species under climate change scenarios.

中文翻译：

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对两种巴西本土森林树种的初始发育动态进行建模

发育模型用于量化初始发育的动态和速率、幼苗期持续时间以及全球变暖对森林物种的影响。这些模型通过气温函数将植物的生理年龄与其形态外观联系起来，该形态外观由主茎上的累积叶片数给出。尽管具有潜力，但对初始发育动态的研究仍然很少，特别是对于本地森林物种。因此，本研究校准并评估了两种发育模型（Phyllochron、Wang 和 Engel）在估计两种巴西本土森林物种（Cybistax antisyphilitica (Mart.) Mart）的累积叶数和幼苗期持续时间方面的表现。（紫葳科）和 Platycyamus regnellii Benth。（豆科）。使用的累积叶数和苗期持续时间数据来自于 2017 年和 2018 年生长季在巴西米纳斯吉拉斯州伊塔茹巴进行的 12 个播种日期的户外实验。这些实验为校准和评估 Phyllochron 以及 Wang 和 Engel 发育模型提供了丰富的数据集。两种发育模型都能够以较低且可接受的误差来预测两个物种的累积叶数，并且对苗期持续时间的估计不太准确。对于抗梅毒衣原体，两个模型在估计累积叶数和苗期持续时间方面非常相似，均方根误差分别为 3.3 个叶和 25 天。对于 P. regnellii，Wang 和 Engel 模型略优于 Phyllochron，误差小于 2.06 叶和 13.1 天。