Maple Reproduction and Sap Flow at Harvard Forest since 2011

Seed production assures the persistence of tree populations and forest cover over the long-term, and so has long interested plant demographers and foresters. Many forest tree species produce seeds synchronously and at irregular intervals across large areas, a phenomenon known as masting. Initiated in spring 2011, this study addresses the mechanisms of mast seeding in sugar maple (Acer saccharum), and its impact on pollinators, seed consumers, and forest carbon dynamics at the Harvard Forest. We monitor seed production (via counts of seeds on trees), flower production, and resource status (via sap collection) on 20 trees. Pollinator dynamics and seed predation (by weevils) are also monitored. In 2015, we added sap and seed monitoring of red maple (Acer rubrum) trees to explore the hypothesis that this non-masting species would have muted dynamics compared to its masting congener.种子生产是树木种群与森林覆盖长期存续的保障，长期以来备受植物种群统计学家与森林学家的关注。多数森林树种会在广阔区域内同步结种，且间隔周期无规律可循，这一现象被称为同步结实（masting）。本研究于2011年春季启动，旨在探究糖槭（Acer saccharum）的同步结实机制，及其在哈佛森林内对传粉者、种子取食者与森林碳动态的影响。研究团队对20株样树的种子生产（通过统计树上的种子数目）、开花量以及资源状态（通过采集树液）进行监测，同时还对传粉者动态与象甲引发的种子捕食情况开展监测。2015年，我们新增了红枫（Acer rubrum）的树液与种子监测项目，以验证如下假说：相较于其同属的同步结实物种，该非同步结实物种的种群动态会更为平缓。