Below ground AudioMoth testing

KEY DETAILS

Principal Investigator: Jonny Timperley
Date; 21 March 2024
Version; 0.1.0
Programme; Rangelands Biodiversity Project (RBP)
Study Site; Lewa-Lolldaiga-Borana-Ngare Ndare (LLBN)
Key partners; University of Liverpool Contact email; jht45@liverpool.ac.uk

1. PREAMBLE

Natural State’s objectives and activities are detailed by a set of accepted Standard Operating Procedures (SOPs). These documents describe the steps involved in all Natural State projects, from data collection to data processing and storage. Each SOP documents key project details and provides methodological details specific to the project. The objectives and background of the project, features of the study area, and details on survey and sampling design may be found in the project Design Document (DD) which is available in the Related Documents section below.

1.1 SOP PURPOSE

To provide a clear step by step guide to the methods implemented in the project, therefore allowing for consistency in data collection and repeatability of all steps involved in a project’s data collection, processing and storage. This is crucial to Natural State’s mission of facilitating nature restoration at scale by using the latest technology and methods to revolutionise impact monitoring for carbon, biodiversity and human well-being.

1.2 SOP SCOPE

This document details how this project will be implemented. All methodological steps are explained, and the principal team members overseeing the project are listed in case further clarification is required. It also further directs readers to where they can find additional information relevant to the project. This document is intended to be printed out and taken to the field for reference sake.

2. GLOSSARY

Experiment: This refers to whether the AudioMoth was deployed for the first experiment (4 day deployment) or the secont experiment (17 day deployment).
Site: This refers to the location where the deployment took place (either clay dominated soil at Kona Safi or sand dominated soil at Mawingu).
Sampling Point: This refers to the sampling replacate within the site, and can be 1, 2 or 3. Sampling point 1 is due north of the centroid (0 degrees), sampling point 2 is south west of the centroid (225 degrees) and sampling point 3 is south east of the centroid (135 degrees).

3. PROJECT OVERVIEW

3.1 PROJECT AIMS

The Below Ground AudioMoth Testing project aims to:

Assess whether different AudioMoth directions affect the to quality of soil audio recordings.
Assess whether different AudioMoth coverings affect the quality of soil audio recordings.
Assess whether the clay and sand content of soil affects the quality of soil audio recordings.
Assess whether the disturbance associated with digging holes to deploy AudioMoths underground affects belowground invertebrate vocal rates.

3.2 PROJECT BACKGROUND

Natural State is conducting these below ground AudioMoth tests prior to Jonny Timperley’s first visit to Natural State, scheduled for June 2024. These tests will help Jonny to decide how he will deploy AudioMoths below ground when he begin his data collection.

3.3 STUDY AREA

This study will take place in the LLBN landscape, ant 2 different sites. One site needs to be dominated by soil with a high clay content, and we have chosen this to be the area around Kona Safi. The other site needs to be dominated by soil with a sand content, and we have chosen this to be the area around Mawingu.

3.4 PROJECT TIMELINE

This project needs to occur in March 2024, before the rains come.

4. SAMPLING PREPERATION

The equipment mentioned in the list below needs to be gathered, checked and packed before sampling begins. If any sensors need to be configured prior to commencing sampling this will be documented below the equipment list.

4.1 EQUIPMENT LIST

24 AudioMoths with hard cases that have clips (pre-programmed at office)
24 micro SD cards that are compatible with AudioMoths
72 fully charged eneloop batteries
Handheld GPS with charged batteries
50m measuring tape
Cellphone with compass
2 large rebars
6 small rebars
Soil auger
Small shovel
Box of sand
1m X 1m quadrat
6 ziploc bags
Permanent marker
Paper and pencil for recording veg cover
Ball of string (quite a lot, 40cm per AudioMoth)
Pink spray paint

4.2 DEVICE CONFIGURATION

AudioMoths need to be programmed in the office before leaving for the field. All 24 AudioMoths need to be programmed with the same settings, which are as follows:

Experiment 1 (4 day deployment):

Setting	Selection
Recording Periods	00:00 – 24:00 UTC
Sample Rate (kHz)	48 kHz
Gain	High
Sleep Duration (s)	30
Recording duration (s)	3570
Band filter	None
Trigger type	None

Experiment 2 (17 day deployment):

Setting	Selection
Recording Periods	04:00 – 13:00 UTC
Sample Rate (kHz)	48 kHz
Gain	High
Sleep Duration (s)	30
Recording duration (s)	3570
Band filter	None
Trigger type	None

Each AudioMoth must then be labelled with a piece of masking tape stuck onto the device inside the case detailing the treatment it will be given. Each of the 24 Audiomoths will have a different label. Label abreviations are as follows:

S for Sand and C for Clay (representative of whether the AM was deployed in sand or clay dominated soil)
N for Natural and S for Sand (representative of whether the hole was filled with naturally occuring soil or sand from the box)
Front for facing forewards/sideways and Down for facing downwards
Sampling location (either 1, 2 or 3)

The 24 labels are as follows:

S N Front 1
S N Front 2
S N Front 3
S N Down 1
S N Down 2
S N Down 3
S S Front 1
S S Front 2
S S Front 3
S S Down 1
S S Down 2
S S Down 3
C N Front 1
C N Front 2
C N Front 3
C N Down 1
C N Down 2
C N Down 3
C S Front 1
C S Front 2
C S Front 3
C S Down 1
C S Down 2
C S Down 3

It is a good idea to keep Clay and Sand AudioMoths in seperate containers as they will be deployed at different locations (Kona Safi for Clay and Mawingu for Sand).

5. SAMPLING PROCEDURES

Each experiment consists of 24 AudioMoths deployed in the field, 12 at the clay soil site (Kona Safi) and 12 at the sandy soil site (Mawingu). The experiment will be run twice, the first time with AudioMoths deployed for 4 days and the second with Audiomoths deployed for 17 days. Experiment 1 and 2 can occur close to each other, but not at exactly the same locations as the disruption caused by digging may affect belowground invertebrate activity and vocalizations. Site 2 should therefore be at least 50m away from site 1.

In each site we would like to have 3 separate sampling points as shown below. The sampling points will be positioned in a triangular fashion, each approximately 10m from the plot centre at bearings 0°, 135°, and 225°. Each sampling point will have four AudioMoths positioned in a square-shaped formation, with each AudioMoth positioned 50cm from each other. These will be inserted by diggin a hole with a soil auger and placing the AudioMoth 20cm below the ground. Please use a green plastic waterproof casing with a black clip for each AudioMoth.

At each of the three sampling points, the four AudioMoths will each have a different treatment. Please randomly position each of the different treatments. These treatments are:

1) AudioMoth with the sensor faced sideways, and the natural soil (which you have just dug out of the ground) placed back on top and around the recorder in a condensed manner (i.e. so there are no air pockets). 2) AudioMoth with the sensor faced downwards, and the natural soil placed back on top and around the recorder in a condensed manner. 3) AudioMoth with the sensor faced sideways, with sand placed on top and around of the recorder so there are no air gaps/pockets. 4) AudioMoth with the sensor faced downwards, with sand placed on top and around of the recorder

The GPS coordinates of the centroid of each site need to be recorded as well as percent vegetation cover and soil moisture content at each sampling point. To measure percent vegetation cover place a 1m X 1m quadrat over each sampling point and estimate percent live vegetation cover, not including dead leaf litter. To measure soil moisture content collect some soil from bottom of 1 20cm deep hole per sampling site and put into a ziploc bag (not a khaki bag as moisture will evaprate from that as you travel). Make sure to seal the ziploc bag. This soil will be processed back at the lab, as described delow.

5.1 BELOW GROUND AUDIOMOTH DEPLOYMENT

Arrive at the desired site (Kona Safi or Mawingu) and select a site centroid. This should be at least 100m away from the road to avoid vehicle noise interferance.
Hammer a large rebar into the centroid of the site and paint the top pink.
Record the GPS coordinates of the centroid.
Use the 50m measuring tape to measure 10m directly north of the centroid (0 degrees on compass). Hammer a small rebar into this point and paint it pink. This is sampling point 1.
Use the 50m measuring tape to measure 10m south west of the centroid (225 degrees on compass). Hammer a small rebar into this point and paint it pink. This is sampling point 2.
Use the 50m measuring tape to measure 10m south east of the centroid (135 degrees on compass). Hammer a small rebar into this point and paint it pink. This is sampling point 3.
Place the 1m X 1m quadrat over each of the 3 sampling points and estimate vegetation cover.
Open all 12 AudioMoths that will be deployed at this site and select the 4 labelled with a 1, meaning they will be deployed at sampling point 1.
Use the soil auger to dig 4 20cm deep holes which are all 50cm apart at sampling point 1, as shown in the figure above.
Take a soil sample from the bottom of one hole and place in a ziploc bag labelled with site and sampling point.
Select an AudioMoth for deployment, note which treatment it has been assigned and remember this.
Switch on the AudioMoth by moving the toggle to “custom” and close the case.
Tie a 40cm long piece of string around the outside of the device ensuring that there is a long tail of string attached to the device.
Place the device in a hole making sure to face it either forwards or downwards according to it’s label, and ensure that the hole is filled with natural soil or sand as indicated by its label. If the device is labelled front point the speaker hole forwards/sideways (parallel to the grounf). If the device is labelled down point the speaker hole downwards into the ground. Do not point the speaker hole up as it will leak water into the device. If the device is labelled sand not natural, place a handful of sand in the hole first, then place the AudioMoth in the hole, then cover with sand until you can no longer see the AudioMoth. Then fill the rest of the hole with natural soil. If the device is labelled natural then fill the hole with only natural soil from the area. When filling the hole with sand/soil make sure that you keep the tail of string sticking out the top to ensure that you can find the AudioMoth again.
Step on top of the hole to compact the soil.
Paint the tail of string pink and paint a pink circle around the hole where the AudioMoth has been burried to ensue that you can find it again.
Repeat with the other 3 AudioMoths for sampling point 1.
Repeat as above for sampling points 2 and 3.
Repeat as above for the second site.

5.2 BELOW GROUND AUDIOMOTH RETRIEVAL

After the correct number of days have passed, navigate to the centroid of the site.
Locate sampling point 1.
Locate the pink string attached to an AudioMoth.
Dig up the AudioMoth.
Open the AudioMoth case and move the toggle to the off position. It is very important that the masking tape stuck on to the device remains in place as this is the only way of identifying the treatment that the device was subject to.
Close the AudioMoth case.
Repeat with the other 3 AudioMoths for sampling point 1.
Repeat as above for sampling points 2 and 3.
Repeat as above for the second site.

6. POST PROCESSING

This section details all steps that need to be followed after returning to the office from the field to ensure that samples are properly processed and stored and that data is uploaded and saved to the correct location.

6.1 SAMPLE PROCESSING AND STORAGE

Upon return from the field take the soil sample bags to the lab (there shoudl be 6 per experiment, 3 from the clay site and 3 from the sand site).
Obtain 6 khaki bags and label them with site (clay or sand) and sampling point (1,2,3).
Weigh one of the khaki bags. Record this weight.
Open the first ziploc bag and transfer a handful of soil into a khaki bag (approximately 50g, but this number does not matter).
Weigh the khaki bag containing the soil and record this weight by writing it onto the khaki bag. This is the wet weight. This measurement will include the weight of the khaki bag.
Fold the top of the bag over and staple it closed.
Repeat as above for the remaining 5 samples.
Arrange with Catherine or Glancy to put the soil samples in an oven at 105 degrees for 24 hours.
Whoever takes the samples out of the oven must weigh each one immediately and record the weight onto the khaki bag. This is the dry weight. This measurement will include the weight of the khaki bag.

6.2 DATA ENTRY AND UPLOADS

Ensure that the percent vegetation cover data collected in the field and the wet and dry soil weights collected in the lab are recorded in the “below_ground_audiomoth_tests” spreadsheet. This spreadsheet is stored in Teams > Field Division > Field Data > RBP > LLBN > Device Testing.
Download the data from each AudioMoth into a separate folder.
Each folder should be named with the AudioMoth number (as written on the device) followed by a space followed by the label from the masking tape written out in full. For example if the first folder came from AudioMoth 20 and had label “S N Front 1” the first folder would be named “20 Sand Natural Front 1”.
Continue as above for all 24 AudioMoths for the experiment.
Upload audio data to Azure Sotrage Explorer.

7.1 DESIGN DOCUMENT

[In Progress]

7.2 OTHER RELEVANT SOPS

None

7.3 DATA ELEMENTS

Survey Design

Manual

Data Collection

Manual: “below_ground_audiomoth_tests” spreadsheet stored in Teams > Field Division > Field Data > RBP > LLBN > Device Testing.

8. REVISION AND VERSION HISTORY AND DESCRIPTION

==XXX==

9. SIGNATURES OF CONFIRMATION

Principal Investigator: ______________ Date: ___________

Director of Impact Insights: ____________ Date: ___________

10. APPENDICES

None currently available