Aquatic vertebrate populations in streams throughout the HJ Andrews Experimental Forest, 2013 to 2019

This multi-year study quantifies the distribution and density of aquatic vertebrates throughout Lookout Creek stream network, including Mack, McRae and Upper Lookout Creeks. We are examining how predictable and consistent the densities and sizes of cutthroat trout and coastal giant salamanders are throughout the network and whether they fluctuate synchronously with vertebrates sizes and densities in Mack Creek that have been measured since 1987 (AS006). We are also examining biomass and condition of individuals across sites. Density and developmental stage of coastal tailed frog tadpoles are noted. We use electroshocking in discrete blocked reaches (depletion and mark-recapture methodologies) to collect individuals that are then weighed, measured and released. Site specific characteristics are measured at each sampling event, including wetted widths and water depths. Broader landscape metrics, including stream gradient and watershed area, were calculated for sites.本项多年期研究对卢考特溪（Lookout Creek）水系网络内水生脊椎动物的分布与种群密度开展量化分析，研究覆盖麦克溪（Mack Creek）、麦克雷溪（McRae Creek）及上卢考特溪（Upper Lookout Creek）。本研究旨在探明该水系网络内割喉鳟（cutthroat trout）与海岸巨螈（coastal giant salamander）的种群密度及个体体长的可预测性与一致性，并探究其变化是否与自1987年起持续监测的麦克溪（Mack Creek）脊椎动物种群密度及体长变化同步（数据集编号：AS006）。此外，本研究还对各采样点位的水生生物个体生物量与健康状况进行调查，同时记录了尾蟾（coastal tailed frog）蝌蚪的种群密度与发育阶段。本研究采用电激法（electroshocking）对划定的连续分段河段实施采样，结合移除法（depletion）与标记-重捕法（mark-recapture）收集个体样本，随后对样本进行称重、体长测量并原地放归。每次采样均会记录对应点位的生境特征，包括河道湿宽与水深。研究人员同时针对各采样点位计算了流域景观整体指标，涵盖河道坡度与流域面积。