Gully remediation effectiveness - Vegetation 2019 - 2020 (NESP TWQ 5.9, CSIRO)

This dataset contains Vegetation and Biomass monitoring data collected for the NESP TWQ Project 5.9, formally NESP TWQ 2.1.4, (Demonstration and evaluation of gully remediation on downstream water quality and agricultural production in GBR rangelands) and Landholders Driving Change (LDC) contracts LRP17-003 and LME17-009. Data is from control and treatment gully sites on commercial grazing properties in the Burdekin.

BOTANAL files describe the biomass, species composition and species attributes such as basal area and cover for hillslope areas above gully erosion sites.

PATCHKEY files describe the landscape condition (proportional) of vegetation patches for hillslope areas above gully erosion sites.

GULLY_VEG describes the biomass, species composition and species attributes such as percent cover for locations within the Gully.

Seven paired Control/Treatment gully sites on commercial grazing properties in the Burdekin being monitored as part of NESP Project 5.9 and NESP Project 2.1.4 (Demonstration and evaluation of gully remediation on downstream water quality and agricultural production in GBR rangelands) and Landholders Driving Change (LDC) contracts LRP17-003 and LME17-009. The key question being asked is "is there measureable improvement in the erosion and water quality leaving remediated gully sites compared to sites left untreated?" The monitoring approach uses a modified BACI (Before after control impact) design.

The aim of the vegetation monitoring in relation to this project is to track change in land condition and vegetation over time on hillslope areas above, and within gullies within control and treatment sites (treatments vary). Linking to changes in downstream water quality.

Methods:

Vegetation metrics were measured on the hillslope above and within each of the monitored gullies at the Pre-wet or end of the dry season ('EOD', October–November) and then again at the post-wet or end of the wet season ('EOW', April). Measurements were initiated in November 2016 at all sites except Mt Wickham which started in August 2018 and at Mt Pleasant and Glen Bowen that began in November 2019.

For BOTANAL and PATCHKEY, Landscape and vegetation condition transects were installed upslope of the uppermost head section on both the treated and control gullies at all sites. Transects were run along slope contours and varied in length and spacing for each site depending on gully-head catchment size. Four to five transects were used at each treatment and control location. Each transect has a fixed beginning and end to facilitate repeat measures. Length and spacing of transects varied between sites dependant on hillslope size. 6 to 8 x 1m quadrats were sampled along each transect at equal spacing giving 30 to 32 samples per site (this may vary due to some changes in study sites over time – eg. New fence placements or inaccessibility due to weather). See "Interactive map of this dataset" in the online resources for layouts at sites.

BOTANAL data was collected along each transect using a 1m² quadrat using the methods of Tothill et al., (1992), with placement of quadrats dependent on transect length at each site (30 quadrats were sampled for each treatment/control area). Metrics included the main pasture species and/or functional group composition and frequency, above-ground pasture biomass (DMY), total cover, litter cover, basal-area %, defoliation level and key soil surface condition metrics (Tongway and Hindley, 1995).

In addition landscape condition was calculated along each transect using PATCHKEY (Abbott and Corfield, 2012). The condition assessments were aggregated to reflect ABCD landscape condition as used across grazed landscapes in the GBR catchments (Aisthorp and Paton, 2004; Chilcott et al., 2005; Bartley et al., 2014). Cover and biomass estimates were calibrated against standard quadrats taken at each site using classified quadrat photographs. Biomass standards were oven dried to attain dry matter yield, removing vegetation water retention error between treatments. A real time kinematic (RTK) survey ran from upslope of the vegetation survey to the valley section for each gully system. Data was collected at 4 to 5 parallel fixed transects above gully locations (hillslope area) – length and spacing of transects varied between sites dependant on hillslope size. See "Interactive map of this dataset" in the online resources for transect locations at sites. PATCHKEY data was collected digitally using custom software on handheld android devices. Survey occurred each year before and after wet season. Biomass is calibrated against cut and dried samples and cover is calibrated against classified quadrat photos – per collector.

GULLY_VEGetation cover and biomass were also measured within each gully, on the gully walls and gully floor. Sampling was initiated at the end of the first wet season (April 2017) for all sites except Mt Wickham which started in August 2018 and at Mt Pleasant and Glen Bowen that began in November 2019. The sampling methodology was very similar to the hillslope survey. A minimum of three transects were measured across each gully, representative of the head, middle and valley sections. At each transect, % cover, biomass and dominant cover type was assessed using 0.25 m² (0.5 x 0.5m) quadrats. Three quadrats were assessed on each wall (six in total) and six quadrats assessed in the deepest part of the channel in the gully floor. Box plots of the % cover and biomass data at the end of each wet season for control and treatment sites were analysed using Sigmaplot Version 14. In most cases a t-test for means and non-parametric Mann-Whitney rank sum test were conducted to evaluate differences between treatment and control sites.

Limitations of the data:

This dataset contains Vegetation monitoring data collected at these gully sites for Pre-wet or end of the dry season ('EOD', October–November) for Hillslope only and then again post-wet of end of the wet season ('EOW', April) for Hillslope and Gully over four reporting periods 2016-2017, 2017-2018, 2018-2019 and 2019-2020. Measurements were initiated in November (EOD) 2016 at all sites except Mt Wickham which started in August (EOD) 2018 and at Mt Pleasant and Glen Bowen that began in November 2019.

Format:

This data collection consists of 4 zip files.

BOTANAL.zip contains eight CSVs containing pre-wet and post-wet survey data for all sites for dates between 2016 and 2020. In addition there is a species (SPP) decode CSV.

PATCHKEY.zip contains eight CSVs containing pre-wet and post-wet survey data for all sites for dates between 2016 and 2020.

GULLY_VEG.zip contains 4 XLSX files containing post-wet gully vegetation survey data for all sites for dates between 2016 and 2020. Post-Wet end of wet (EOW). Individual tabs for each site record the raw data as captured in the field. The "Stds" tab calculated the calibration from BIO code to actual biomass. The "all_for_stats" sheet (or "All End of Wet" in file "Gully_Veg_2017-2018.xlsx") is the intermediate sheet for collation of data in "Wall" and "Channel" sheets ready for analysis in stats package. "Summary" tab contains summary data for the report.

Veg_Spatial.zip consists of three shapefiles, Veg_transect_Locations.shp and Veg_Quadrat_locations.shp contain the transects and quadrat locations respectively in MGA94 Z55 coordinates for the BOTANAL and PATCHKEY surveys. Gully_Veg_locations.shp contains locations of the GULLY_VEG gully vegetation surveys in EPSG:4326 coordinates.

Data Dictionary:

Site Codes are as follows:
- MIN = Minnievale
- MV = Meadowvale
- MW = Mount Wickham
- SB = Strathbogie
- VP = Virginia Park
- MTP = Mount Pleasant
- GLB = Glen Bowen
<T/C> - Treatment/Control

Note:
Original Strathbogie control sites exhibited very high erosion rates and treatment was undertaken in Oct/Nov 2019 to stabilise. The treatment site "SBT" became the control site and the site ID was changed for "SBT (C)". Similarly, the control site "SBC" became the treatment site and the site ID was changed to "SBC / SBT2 (T)". Sites names were standardised for all data files except the GULLY_VEG.ZIP files. If you need more information, please contact Dr Rebecca Bartley.

BOTANAL CSV headers:
- ID: Unique identifier for sample
- USER: Collector name/initials
- SITE: Abbreviated site name - Meadowvale (MedV), Minnivale (MinV), Virginia Park (VP), Strathbogie (SB) and Mt Wickham (Mt W). Abbreviations are followed by a C for control site and T for treatment site – eg. MedVC, MedVT.
- TRAN: Transect number, numbered from nearest to gully head – see attached GIS layer "Sites_transect and quadrat.shp.zip"
- QUAD: Quadrat number per transect - see attached GIS layer "SIte_quadrat_locations.shp"
- DATE: Date and time
- SP1 to SP5: Species name abbreviated using first two letters of genus and first three of species name eg. Bothriochloa pertusa = boper. Species usually recorded in order of highest biomass represented. See "BOTANAL_Spp_decode.csv" for decode of species codes.
- SPP1 to SPP5: Species proportion (%) estimate by biomass of quadrat for each of species 1 to 5
- YIELD: Total biomass estimate for quadrat in kg/ha
- DEFOL: Estimated grazing defoliation of the pasture within a quadrat. Ordinal – 1=0-5%, 2=5-25%, 3=25-50%, 4=50-75% and 5=75-100%
- BASAL: Estimated basal area of Perennial tussock grasses. % of quad
- COVER: Foliage projected cover of pasture species, % of quad
- LITTER: Litter cover, % of quad
- BARE: Bare ground, % of quad (optional – usually the inverse of total cover )
- HARD: Soil hardness (scaled after Tongway et al 2004 – landscape functional analysis). Categorical – 1=Easily broken, 2=Moderately hard, 3=Very hard, 4=Sand, 5=Self mulching.
- DEPOS: Deposition from erosion processes, (scaled after Tongway et al 2004 – landscape functional analysis) Categorical – 1=Insignificant, 2=slight, 3=moderate, 4=extensive
- INCORP: Litter incorporation into soil surface. (scaled after Tongway et al 2004 – landscape functional analysis) Categorical – 1=nil, 2=low, 3= moderate, 4=high
- EROSION: (scaled after Tongway et al 2004 – landscape functional analysis) Categorical – 1=Insignificant, 2=slight, 3=moderate, 4=extensive.

PATCHKEY CSV Headers:
- ID: Unique identifier for sample
- DATE: Date and time
- RECORDER: Collector name/initials
- SITE: Abbreviated site name - Meadowvale (MedV), Minnivale (MinV), Virginia Park (VP), Strathbogie (SB) and Mt Wickham (Mt W). Abbreviations are followed by a C for control site and T for treatment site – eg. MedVC, MedV.
- TRAN: Transect number, numbered from nearest to gully head – see attached GIS layer "Sites_transect and quadrat.shp.zip"
- PATCH_NO: Number of the patch occurring along a transect – patches can be measured from either end of the transect.
- DOMINANT: Dominant vegetation functional group within a patch. 3P=Native decreaser perennial tussock grasses, INPG=Native increaser perennial tussock grasses, EXPGT=Exotic perennial tussock grasses, EXPGS=Exotic perennial stoloniferous grasses (eg. Indian couch), ANNG=Annual grasses and forbs, SHRUBS=Shrubs less than 2m, BARE=Bare earth.
- BASAL: Estimated basal area of Perennial tussock grasses. % of patch
- LITTER: Litter cover. % of patch
- YIELD: Total biomass estimate for patch in kg/ha
- BARE: Bare ground % of patch
- EROSION: Erosion severity (scaled after Tongway et al 2004 – landscape functional analysis ) Categorical – 1=Insignificant, 2=slight, 3=moderate, 4=extensive
- HARDNESS: Soil hardness (scaled after Tongway et al 2004 – landscape functional analysis). Categorical – 1=Easily broken, 2=Moderately hard, 3=Very hard, 4=Sand, 5=Self mulching.
- INCORPORATION: Litter incorporation into soil surface. (scaled after Tongway et al 2004 – landscape functional analysis) Categorical – 1=nil, 2=low, 3= moderate, 4=high
- PATCH_TYPE: Patch type condition classification auto-calculated in software from the above inputs
- PATCH_EST: Patch type condition estimated by user – overrides calculated value if required
- PATCH_LENGTH: Measured patch length along transect

Gully_Veg XLSX spreadsheets:
Spreadsheets contain tabs for each gully site with fields as follows:
- Date: date of measurement
- Quad: quadrat measured (not always numbered)
- Loc: location on gully –cross sections from RTK. Numbers are in order from 1 nearest incrementing by 1 downstream
- Pos: walls (left bank (lb), right bank (rb)) or channel
- BIO: biomass code from 0 to 5 – this is a surveyor-specific estimate which is calibrated to actual biomass using standards
- Cov: estimate of percent cover
- Sp: species composition. Please, contact Dr Rebecca Bartley for information regarding species codes.
- COMMENT: any comments relating to the quadrat or measurement
- Biomass (kg/ha): biomass calculated using standards
- Surveyor: surveyor number (different standards calibration required for different surveyors)

Each Gully_veg spreadsheet also contains additional tabs for calibration or summarising the survey data.
- stds: contains calibration data for biomass estimation from Biomass codes.
- Summary: summary statistics by site and location
- All for Stats: an intermediate sheet used for deriving summary statistics
- Channel: an intermediate sheet used for deriving summary statistics
- Walls: an intermediate sheet used for deriving summary statistics
- Instructions: Instructions for user

Gull_Veg_locations FIELDNAMES:
- Gully: Gully site code
- Survey: "gully" for linear gully geometry or "alluvial Gully" for alluvial gully geometry
- Location: Survey location for corss-referencing with Gully_Veg.XLSX sheets
- POINT_X: Easting (m) in MGA94 UTM coordinates
- POINT_Y: Northing (m) in MGA94 UTM coordinates

Veg_transect_Locations.shp FIELDNAMES:
- TRANSECT: transect number
- SITE: site code

Veg_Quatrat_Locations.shp FIELDNAMES:
- TRANSECT: transect number
- QUADRAT: quadrat number
- SITE: site code
- POINT_X: Easting (m) in MGA94 UTM coordinates
- POINT_Y: Northing (m) in MGA94 UTM coordinates

References:

Bartley, R., Hawdon, A., Henderson, A., Abbott, B., Wilkinson, S., Goodwin, N. and Ahwang, K. (2020). Quantifying the effectiveness of gully rehabilitation on off-site water quality: results from demonstration sites in the Burdekin catchment (2019/20 wet season). Report to the National Environmental Science Programme. Reef and Rainforest Research Centre Limited, Cairns (138 pp.).

Baker, B., Hawdon, A. and Bartley, R., 2016. Gully remediation sites: water quality monitoring procedures, CSIRO Land and Water, Australia.

Abbott BN and Corfield JP (2012) PATCHKEY – A patch based land condition framework for rangeland assessment and monitoring, BACKGROUND INFORMATION AND USERS GUIDE. CSIRO, Australia.

Tothill, J. C., et al. (1978). 1, BOTANAL - a comprehensive sampling and computing procedure for estimating pasture yield and composition. 1. Field sampling., CSIRO Division of Tropical Crops and Pastures.

Tongway, D. J. and N. L. Hindley (2004). Landscape Function Analysis Manual: Procedures for Monitoring and Assessing Landscapes with Special Reference to Minesites and Rangelands. Ver. 3. 1. Canberra, CSIRO

Data Location:

This dataset is filed in the eAtlas enduring data repository at: data\custodian\2019-2022-NESP-TWQ-5\5.9_Gully-remediation-effectiveness-vegetation