In situ Didymosphenia regrowth manipulation

Knowledge graph centered on In situ Didymosphenia regrowth manipulation with 25 nodes and 75 connections. Top connected: phenological mismatch, Bacteria, Daphnia, Didymosphenia geminata, invasive species impacts.

Method synopsis

Experimental removal of D. geminata cells and stalks from stream rocks to test regrowth capacity under natural conditions with different initial stalk densities.

Synthesized from method descriptions across 2 papers using this protocol.

Procedure from a recent peer-reviewed implementation

Steps below were extracted from the most recent peer-reviewed implementation of this protocol in the corpus — <i>Didymosphenia geminata</i> blooms are not exclusively driven by low phosphorus under experimental conditions (2020), Hydrobiologia. The protocol was originally introduced by Regrowth of Didymosphenia geminata after a removal event. (2012). Implementations in other papers (listed below) may differ.

1. Site selection for in situ experiment
   Identified reaches of three different streams (East River, Copper Creek, Washington Gulch) in the vicinity of Crested Butte, Colorado that were supporting D. geminata blooms.
   Quantities: 3 streams, 8 replicate blocks per streamDuration: Summer 2012 (July 7)Conditions: Streams supporting active D. geminata blooms
2. Rock selection and treatment setup
   Within each block, three similarly sized cobble rocks (110-220 mm diameter) were selected: two with initially high densities of stalked D. geminata (minimum 80% stalk cover, bloom rocks) and one with low density (maximum 20% stalk cover, non-bloom). One bloom rock from each block was gently scrubbed with a nylon brush to remove all D. geminata cells and stalks.
   Quantities: 3 rocks per block, 8 blocks per stream, 24 rocks total per stream across 3 streams = 72 rocks totalDuration: Single setup eventConditions: In stream conditions
   Equipment: nylon brush, cobble rocks 110-220 mm diameter
3. In situ growth monitoring
   Three rocks constituting a block were placed close together in the stream at similar depths and water velocities. Monitored twice weekly for percent cover and thickness of D. geminata for a period of 5 weeks. Standing crop index (SCI) calculated by multiplying percent cover by thickness (cm) of the mat.

Typical Equipment

• nylon brush
• SonTek FlowTracker
• Thermo Scientific GENESYS 10S UV-VIS Spectrophotometer

Output Measurements

• standing crop index
• percent cover
• stalk thickness
• cell division frequency

Papers Using This Protocol (2)

Species Studied With This Protocol