A network of time lapse cameras for monitoring forest plant phenology

气候变暖等环境变化可能对植物生命中年度事件的时间产生重大影响，例如叶子脱落或开花，这反过来又对植物适应性和与其他物种的相互作用产生重要影响。 例如，气候变暖通常会导致提早开花，但人们对所涉及的特定气候变量仍然知之甚少，而且气候变暖是否会导致种群（例如不同海拔的种群）之间的基因流动增加或减少（通过开花时间的日益趋同或趋异）的问题也是未知的。 在森林生态系统中，林下植物相对于树冠的叶片出现的相对时间可以对春季的高光期产生巨大影响，从而对碳增益产生巨大影响，但目前还不清楚林下植物与树冠的叶片出现对变暖的反应有多大程度的差异。 要回答这些问题，以及其他许多问题，需要简单但耗时的观察，不仅要在特定的生长季节内进行高频率的观察，而且要在许多年内在许多地块上进行观察。 这样的数据集是非常罕见的，即使是最著名的情况下，通常只包括第一个开花日期，而不是整个年度开花时间表。 2016年将标志着在魁北克省梅甘蒂克山国家公园沿着海拔梯度的12个长期监测地块中进行开花物候观测的第四年，其中植被从低海拔的温带落叶林过渡到高海拔的针叶林。 在这里，我建议在这些地点安装一个延时摄影机网络，以便：（1）增加观测频率，以便校准我们的统计方法，这些方法使用3-4天间隔收集的数据，（2）允许相对廉价的方法（3）对林下植被和林冠层的落叶时间进行长期观测。 迄今为止，我们的物候观测一直是劳动密集型的，因此只关注开花时间。 从这项研究中得到的数据将提供一种测试有关物候变化的原因和后果的关键问题的方法（见上文），并为多年来关于这一主题的更有针对性的实验和观察研究提供基础。

Environmental change such as climate warming can have a major impact on the timing of annual events in the life of a plant, such as leaf-out or flowering, which in turn have important consequences for plant fitness and interactions with other species. Climate warming, for example, often causes earlier flowering, but the particular climate variables involved remain poorly understood, and the question of whether warming might cause gene flow among populations (e.g. at different elevations) to increase or decrease (via increasingly convergent or divergent flowering times) is unknown. In forest ecosystems, the relative timing of leaf emergence in understory plants relative to the tree canopy can have a huge impact on the period of high light in spring, and therefore on carbon gain, but it is unclear to what degree leaf emergence in the understory vs. canopy respond differentially to warming. Answering these questions, and many others, requires simple but time-consuming observations, not only at a high frequency within a given growing season, but also over many years and in many plots. Such data sets are exceedingly rare, with even the best-known cases typically including only first flower dates rather than the entire yearly flowering schedule. 2016 will mark the fourth year of flowering phenology observations in a set of 12 long-term monitoring plots along an elevational gradient in Parc national du Mont Mégantic, Québec, where vegetation transitions from temperate deciduous forest at low elevation to coniferous boreal forest at high elevation. Here I propose to install a network of time-lapse cameras at these sites in order to: (1) increase the frequency of observations to allow calibration of our statistical methods, which use data collected on 3-4 day intervals, (2) permit a relatively inexpensive means (in terms of operational costs) of ensuring continual long-term data, and (3) launch long-term observations of the timing of leaf-out in the understory vs. the canopy. Our phenological observations to date have been labour-intensive, and have thus focused only on flowering time. The resulting data from this research will provide both a means of testing key questions concerning the causes and consequences of changes in phenology (see above), and provide the foundation for more focused experiments and observational studies on this topic over many years.