DOI: 10.5061/dryad.587bb57
title: Data from: Technical note: rapid image-based field methods improve the quantification of termite mound structures and greenhouse-gas fluxes

description: Termite mounds (TMs) mediate biogeochemical processes with global
 relevance, such as turnover of the important greenhouse gas methane (CH4).
 However, the complex internal and external morphology of TMs impede an
 accurate quantitative description. Here we present two novel field
 methods, photogrammetry (PG) and cross-section image analysis, to quantify
 TM external and internal mound structure of 29 TMs of three termite
 species. Photogrammetry was used to measure epigeal volume (VE), surface
 area (AE) and mound basal area (AB) by reconstructing 3D models from
 digital photographs, and compared against a water-displacement method and
 the conventional approach of approximating TMs by simple geometric shapes.
 To describe TM internal structure, we introduce TM macro- and
 micro-porosity (θM and θµ), the volume fractions of macroscopic chambers,
 and microscopic pores in the wall material, respectively. Macro-porosity
 was estimated using image analysis of single TM cross-sections, and
 compared against full x-ray tomography (CT) scans of 17 TMs. For these TMs
 we present complete pore fractions to assess species-specific differences
 in internal structure. The PG method yielded VE nearly identical to a
 water-displacement method, while approximation of TMs by simple geometric
 shapes led to errors of 4–200 %. Likewise, using PG substantially improved
 the accuracy of CH4 emission estimates by 10–50 %. Comprehensive CT
 scanning revealed that investigated TMs have species-specific ranges of θM
 and θµ, but similar total porosity. Image analysis of single TM
 cross-sections produced good estimates of θM for species with thick walls
 and evenly distributed chambers. The new image-based methods allow rapid
 and accurate quantitative characterisation of TMs to answer ecological,
 physiological and biogeochemical questions. The PG method should be
 applied when measuring greenhouse-gas emissions from TMs to avoid large
 errors from inadequate shape approximations.
description: Termite mound surface
 mesh models3-D surface mesh models
 of termite mounds generated by photogrammetry using SfM algorithms with
 the software Agisoft Photoscan Standard.PG_models.zipTermite-mound cross-section imagesRGB and binary images of termite mound cross sections to determine full (closed) and chambers (holes) cross-section area for estimating mound macro-porositycross-sections.zipCT scans binary imagesCT-scan binary images of termite mounds to determine full (closed) volume and volume fractions of chambers (holes) and wall material (solid) with a supplied Matlab scriptCT_binary.zipDICOM images termite mound Mn1Raw DICOM image files of CT-scanned termite mound Mn1NauerPA_201806_termite-mound_Mn1-2016_CT-scan_raw.zipDICOM images termite mound Mn2Raw DICOM image files of CT-scanned termite mound Mn2NauerPA_201806_termite-mound_Mn2-2016_CT-scan_raw.zipDICOM images termite mound Mn4Raw DICOM image files of CT-scanned termite mound Mn4NauerPA_201806_termite-mound_Mn4-2016_CT-scan_raw.zipDICOM images termite mound Mn6Raw DICOM image files of CT-scanned termite mound Mn6NauerPA_201806_termite-mound_Mn6-2016_CT-scan_raw.zipDICOM images termite mound Mn8Raw DICOM image files of CT-scanned termite mound Mn8NauerPA_201806_termite-mound_Mn8-2016_CT-scan_raw.zipDICOM images termite mound Mn9Raw DICOM image files of CT-scanned termite mound Mn9NauerPA_201806_termite-mound_Mn9-2016_CT-scan_raw.zipDICOM images termite mound Ms1Raw DICOM image files of CT-scanned termite mound Ms1NauerPA_201806_termite-mound_Ms1-2016_CT-scan_raw.zipREADMEmetadataMetadata on termite mounds and physical properties analysisData and scripts for image/data analysisData and R script on termite mound physical parameters; Matlab script and ImageJ/Fiji macros used for image analysis of termite mound CT scans and cross sections.data_scripts.zipMs1DICOM images termite mound Ms3Raw DICOM image files of CT-scanned termite mound Ms3NauerPA_201806_termite-mound_Ms3-2016_CT-scan_raw.zipDICOM images termite mound Ms5Raw DICOM image files of CT-scanned termite mound Ms5NauerPA_201806_termite-mound_Ms5-2016_CT-scan_raw.zipDICOM images termite mound Ms6Raw DICOM image files of CT-scanned termite mound Ms6NauerPA_201806_termite-mound_Ms6-2016_CT-scan_raw.zipDICOM images termite mound Ms7Raw DICOM image files of CT-scanned termite mound Ms7NauerPA_201806_termite-mound_Ms7-2016_CT-scan_raw.zipDICOM images termite mound Tp1Raw DICOM image files of CT-scanned termite mound Tp1NauerPA_201806_termite-mound_Tp1-2016_CT-scan_raw.zipDICOM images termite mound Tp2Raw DICOM image files of CT-scanned termite mound Tp2NauerPA_201806_termite-mound_Tp2-2016_CT-scan_raw.zipDICOM images termite mound Tp3Raw DICOM image files of CT-scanned termite mound Tp3NauerPA_201806_termite-mound_Tp3-2016_CT-scan_raw.zipDICOM images termite mound Tp4Raw DICOM image files of CT-scanned termite mound Tp4NauerPA_201806_termite-mound_Tp4-2016_CT-scan_raw.zipDICOM images termite mound Tp5Raw DICOM image files of CT-scanned termite mound Tp5NauerPA_201806_termite-mound_Tp5-2016_CT-scan_raw.zipDICOM images termite mound Tp6Raw DICOM image files of CT-scanned termite mound Tp6NauerPA_201806_termite-mound_Tp6-2016_CT-scan_raw.zip