SBC LTER: Reef: Long-term experiment: Kelp removal: Invertebrate and algal density

These data describe the abundance of common reef associated
species of macro invertebrates and macroalgae 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 number of individuals of
approximately 50 taxa were recorded by divers along 40 m transects
within each plot. Small species of macroalgae and macinvertebrates
were counted within six permanent 1 m 2 quadrats positioned uniformly along the 40 m transect, while
larger species were counted within four contiguous 20
m 2 sub-sections of each 40 m x 2 m
transect. Also included at the quadrat scale are estimates of an
average size-related measurement of each species, which was
developed specifically for each species for the purpose of
estimating its biomass. The 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
last experimental removals of giant kelp occurred in winter 2016
or winter 2017, depending on the site. Data collection continued
in all plots until spring 2023 to document the recovery trajectory
of the reef fish community following the cessation of experimental
kelp removal.

本数据集记录了长期定位实验永久样地内常见礁栖大型无脊椎动物（macroinvertebrates）与大型藻类（macroalgae）的丰度。该实验旨在探究巨藻（giant kelp）干扰的频率与强度变化对海带林（kelp forest）群落结构及生产力的影响轨迹。研究人员通过潜水员在每个样地的40米样带（transect）上记录了约50个分类单元的个体数量：小型大型藻类与大型无脊椎动物的个体数在沿该样带均匀布设的6个永久1平方米样方（quadrat）中统计得到，而大型物种则在每个40米×2米样带的4个连续20平方米子区域内完成计数。样方尺度的统计数据还包含针对各物种专门开发的平均体型相关测量值，用于估算该物种的生物量（biomass）。本实验于2008年在圣巴巴拉海峡（Santa Barbara Channel）大陆沿岸的5个礁区站点启动，设置了两种海带移除处理方案：其一为年度海带移除处理，用于模拟冬季波浪干扰的频率与强度升高；其二为持续海带移除处理，用以评估巨藻对群落的影响效应。各站点的最后一次实验性巨藻移除分别于2016年冬季或2017年冬季完成。所有样地的数据采集持续至2023年春季，以记录实验性海带移除停止后礁区鱼类群落的恢复轨迹。