Fern Understory as an Ecological Filter at Harvard Forest 1993-1995

This project is was an investigation of the role of the fern understory as an ecological filter that influences the organization of the tree seedling bank in New England deciduous forests. The data files summarize a series of field experiments conducted from 1993 to 1995 evaluating the response of seed germination and seedling growth and survival to experimental understory manipulation. These field studies involved three experimental manipulations of the fern understory: 1) removal of ferns 2) ferns tied back (to remove above-ground shading) 3) ferns left intact (control). These manipulations were established in 180 - 1m2 plots spanning six field sites and 2 different fern species (3 understory manipulations x 2 understory fern species x 6 sites x 5 replicates/site = 180 experimental plots).

本项目旨在探究蕨类下层植被作为生态过滤因子，对新英格兰落叶林内树木幼苗库群落组织模式的调控作用。本研究的数据文件汇总了1993年至1995年间开展的一系列野外实验结果，用以评估种子萌发、幼苗生长与存活状况对下层植被人工调控的响应情况。该野外研究包含三类蕨类下层植被人工调控处理：1）移除蕨类植物；2）将蕨类植株绑缚固定（以消除地上遮荫效应）；3）保留蕨类原状（对照组）。此类调控实验共设置于覆盖6个野外样点、2种下层蕨类物种的180个1平方米样地中，实验设计为：3种下层植被调控方式 × 2种下层蕨类物种 × 6个野外样点 × 每个样点5次重复，总计180个实验样地。