Percent light penetration: Seedling Addition Experimant in Field D

The purpose of this experiment is to determine the extent to which species not normally present in a small plot are able to survive and potentially reproduce if added to the plot as seedlings. In the area of Field D in which this experiment is to be done, the average 4 x 4 meter area contains approximately 30 species of vascular plants. Into replicate 4 x 4 meter areas we will either add no species or we will add the seedlings of 50 native prairie species. These were grown by Prairie Restoration, Inc. and were planted on May 27-28, 1993.

In adding the seedlings of a variety of species to these plots we will, for all cases, add three seedlings per species into a given plot. These will be fairly uniformally spaced throughout each plot. Thus, the average distance between seedlings will be approximately 28cm apart.

本实验旨在探究：若将正常情况下不存在于该小型样地内的物种幼苗引入样地，其在该样地中的存活及潜在繁殖能力可达何种程度。本实验将在野外D区开展，该区域内平均每4×4米样地约分布有30种维管植物（vascular plants）。我们将对重复设置的4×4米样地施加两种处理：不引入任何物种，或引入50种本土草原物种（native prairie species）的幼苗。这些幼苗由Prairie Restoration, Inc.培育，并于1993年5月27日至28日完成种植。
在向上述样地添加各物种种苗时，我们将统一为每个样地内的单个物种栽种3株幼苗，并确保其在样地内分布相对均匀，由此使得幼苗间的平均间距约为28厘米。