Canopy Trimming Experiment (CTE) plant seedling measurements

Seedlings were measured before and after treatments to determine how alterations in canopy openness and detritus affect seedling densities and life histories (growth, mortality, recruitment). It was predicted that plots experiencing canopy openness with detritus removed would have the quickest increase in seedlings (recruitment and growth), especially of early successional (light demanding) species, such as Cecropia. Seedlings in plots that received no canopy manipulation but had detritus deposited is predicted to have near-total mortality initially (low light and high physical inhibition due to detritus). Treatment plots experiencing both canopy manipulation and addition of detritus would initially experience near-total mortality, with some light demanding seedlings establishing and growing through detritus with time.

本研究对各处理实施前后的幼苗开展测定，以明确林冠开度(canopy openness)与枯落物(detritus)的变化对幼苗密度及生活史（生长、存活、更新）的影响。研究预测，经林冠开度调控且移除枯落物的样地，幼苗更新与生长的增长速度最快，其中喜光型早期演替物种（如号角树属(Cecropia)）的表现尤为突出。未开展林冠调控但添加枯落物的样地中的幼苗，初始死亡率接近百分之百，这是由于光照不足且枯落物带来了较强的物理抑制效应。同时实施林冠调控与枯落物添加的处理样地，初始阶段幼苗死亡率同样接近百分之百，但随着时间推移，会有部分喜光幼苗成功定植并穿透枯落物完成生长。