SBC LTER: Reef: Long-term experiment: Kelp removal: Cover of bottom substrate and sand depth

These data describe the percent cover of eight bottom substrate types within permanent plots of a long-term experiment designed to examine trajectories of change in the structure and productivity of kelp forest communities in response to changes in the frequency and severity of disturbance to giant kelp. The type of bottom substrate is recorded at 80 uniformly spaced points along permanent 40m x 2m transects. Percent cover of each substrate type on transect is estimated as the proportion of the 80 points contacted by the substrate type x 100. In cases where the substrate type is sand the depth of the sand is measured. The kelp disturbance experiment was initiated in 2008 at five reef sites along the mainland coast of the Santa Barbara Channel and included an annual kelp removal treatment designed to simulate increases in the frequency and severity of winter wave disturbance and a continual kelp removal treatment that allowed the effects of giant kelp on the community to be evaluated. The two tables in this data package include: 1) The percent cover of eight bottom substrate types; and 2) the sand depth of each sampling point (sand depth = 0 if substrate type is not sand)

本数据集记录了一项长期实验的永久样地（plot）内8种底质（bottom substrate）的盖度百分比（percent cover）。该实验旨在探究巨藻（giant kelp）扰动的频率与强度变化下，海带林群落结构与生产力的变化轨迹。
实验沿40米×2米的永久样带（transect），在80个均匀分布的采样点上记录底质类型。样带内每种底质的盖度百分比通过该类型底质覆盖的80个采样点的占比乘以100计算得出。若采样点的底质类型为沙质，则同步测量沙层厚度。
本巨藻扰动实验于2008年在圣巴巴拉海峡大陆沿岸的5个礁区启动，设置两类海带移除处理：一类为年度海带移除处理，用于模拟冬季波浪扰动频率与强度的增加；另一类为持续海带移除处理，用以评估巨藻对群落的调控效应。
本数据包包含两张数据表：1）8种底质类型的盖度百分比；2）各采样点的沙层厚度（若底质非沙质，则沙层厚度记为0）。