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 m2
quadrats positioned uniformly along the 40 m transect, while
larger species were counted within four contiguous 20
m2 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野外实验永久样地内，与礁生境共生的常见大型无脊椎动物（macro invertebrates）和大型藻类（macroalgae）的丰度。该长期实验旨在探究巨藻（giant kelp）扰动的频率与强度变化下，海藻林群落结构与生产力的动态变化轨迹。研究人员依托潜水员在每个样地的40米样带（transect）沿线，记录了约50个分类单元的个体数量。沿该样带均匀布设的6个1平方米永久样方（quadrat）中，统计小型大型藻类和大型无脊椎动物的个体数；而每个40米×2米样带的4个相邻20平方米亚区，则用于计数大型物种的个体数。在样方尺度的记录项中，还包含针对各物种专门开发的平均个体大小相关指标估算值，用于该物种的生物量估算。本实验于2008年在圣巴巴拉海峡（Santa Barbara Channel）大陆沿岸的5个礁体位点启动，设置两类处理措施：其一为年度巨藻移除处理，用以模拟冬季波浪扰动频率与强度的提升；其二为持续巨藻移除处理，用于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。后续所有样地的数据采集持续至2023年春季，以记录实验性巨藻移除停止后，礁体鱼类群落的恢复动态轨迹。