Riparian controls on light availability, primary producers, invertebrates, fish and salamanders in streams in and near the Andrews Experimental Forest, 2014-2018

The goal of this data collection effort was to determine how the age, stage, and structure of the riparian forest relates to stream primary producers and stream biota. Data were collected on stream habitat, benthic algal, biota (fish, salamanders and macroinvertebrates), and riparian forest cover across a total of 9 streams: 7 streams in the HJ Andrews basin/Lookout Creek stream network; one stream in the westward adjacent Blue River basin, and one stream in the eastward adjacent Deer Creek river basin. In each stream there were 2 study reaches – one bordered by old-growth riparian forest and the other bordered by regenerated second-growth riparian forest on at least one bank (with a stand ages that generally ranged between 30 and 60 years). In each study reach (80 – 150 m), we collected the following data: pool habitat, wetted and bankfull widths, large wood abundance and volume, riparian forest canopy cover, benthic algae accrual on tiles, stream macroinvertebrate abundances (from 6 replicate surber samplers, which were pooled and then sub-sampled, identified and measured), age 1+ cutthroat trout (Oncorhynchus clarkii clarkii) abundance and biomass, age 0+ (young-of-year) trout abundance and biomass, coastal giant salamander (Dicamptodon tenebrosus) abundance and biomass. Fish and salamander abundances were calculated by either mark-recapture or multiple pass depletion methods.

本数据集采集工作的核心目标，在于明确河岸带森林（riparian forest）的年龄、演替阶段与结构，如何与溪流初级生产者及溪流生物群落产生关联。本次研究共覆盖9条溪流，采集了溪流生境、底栖藻类、溪流生物（鱼类、蝾螈及大型无脊椎动物）以及河岸带森林覆盖度相关数据：其中7条溪流隶属于HJ Andrews盆地/瞭望溪（Lookout Creek）水系网络；1条溪流位于西侧相邻的蓝河（Blue River）流域，剩余1条溪流位于东侧相邻的鹿溪（Deer Creek）流域。每条溪流均设置2处研究河段：一处以原生河岸带森林为岸界，另一处则至少有一侧岸界为更新形成的次生河岸带森林，其林分年龄普遍介于30至60年之间。每处研究河段（长度为80~150米）均采集以下数据：深潭生境状况、湿周宽度与满岸宽度、大型木质残体的丰度与体积、河岸带森林冠层覆盖率、陶片基质上的底栖藻类附着量、溪流大型无脊椎动物丰度（通过6组重复Surber采样器（Surber Sampler）采集样本，经混合、分样、鉴定与计量后统计）、1龄及以上割喉鳟（Oncorhynchus clarkii clarkii）的丰度与生物量、0龄（当年稚鱼，young-of-year）鳟鱼的丰度与生物量，以及海岸巨蝾螈（Dicamptodon tenebrosus）的丰度与生物量。鱼类及蝾螈的种群丰度通过标记重捕法或多次通过移除法进行估算。