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)

本数据集记录了长期固定样地内8种海底底质类型的盖度百分比。该长期实验旨在探究巨藻林群落结构与生产力的变化轨迹，以响应巨藻所受干扰的频率与强度变化。研究沿固定的40m×2m样带，在80个均匀布设的采样点上记录海底底质类型。样带上每种底质类型的盖度百分比，通过该底质类型覆盖的采样点数量占总采样点数（80个）的比例乘以100计算得到。若底质类型为沙质，则同步测量沙层厚度。本巨藻干扰实验于2008年在圣巴巴拉海峡大陆沿岸的5个礁区站点启动，实验设置两类巨藻移除处理：其一为年度巨藻移除处理，用于模拟冬季波浪干扰的频率与强度提升；其二为持续巨藻移除处理，用以评估巨藻对群落的生态效应。本数据包内含两张数据表：1）8种海底底质类型的盖度百分比；2）各采样点的沙层厚度（若非沙质底质，则沙层厚度记为0）