ammonium in soil
Type of resources
Contact for the resource
Great Western Woodlands, Changes in Plant Diversity Indices, Composition and Cover in Eucalyptus salubris Woodlands Across Time Since Fire Chronosequence, 2012
The data set contains information on plant diversity indices, species composition, vegetation cover and edaphic properties from the <i>Eucalyptus salubris</i> woodlands, Great Western Woodlands site. The data represents changes in plant diversity due to disturbance with time since fire in a chronosequence.
We investigated recovery of soil chemical properties after restoration in semi-arid Western Australia, hypothesising that elevated nutrient concentrations would gradually decline post planting, but available phosphorus (P) concentrations would remain higher than reference conditions. We used a space-for-time substitution approach, comparing 10 planted old field plots with matched fallow cropland and reference woodlands. Sampling on planted old fields and reference woodland plots was stratified into open patches and under tree canopy to account for consistent differences between these areas. Soil samples to 10 cm depth were collected at 20 points across 30 plots. Ten samples were randomly collected and combined from locations beneath trees and a further 10 samples collected in gaps and combined, resulting in one soil sample for beneath tree canopy and another one for gap areas. Sampling occurred in autumn 2017 to capture potentially high concentrations of soil nitrate following the seasonal die-back of exotic annual plants typical of this Mediterranean-climate region. Samples were stored at 4 °C in plastic zip-lock bags until delivery to the CSBP Limited (Bibra Lake, WA) laboratories. Chemical parameters measured were plant available P (Colwell), plant available N (nitrate and ammonium), total N, plant available potassium (Colwell) and plant available sulphur (KCl 40). Lastly, electrical conductivity, pH (H2O, CaCl2), and soil texture were quantified as differences among plots could affect nutrient availability and soil chemistry. Soil available nutrients were also measured using Plant Root Simulator (PRS)TM resin probes (Western Ag Innovations, 2010, https://www.westernag.ca/inn). Probes contain anion or cation exchange membranes within a plastic stake. The membranes act as a sink for collecting nutrients and continuously absorb ions during deployment. Four anion and cation probes were placed vertically in the top 15 cm of soil at each stratification. Probes were left in the ground for three months during the growing season, from August to November 2017. This period was deemed suitable for semi-arid regions to achieve sufficient nutrient uptake but not too long to saturate probes. After removal, probes were cleaned with deionized water and sent to Western Ag Innovations (Canada) for analysis. All soil chemical analyses were conducted under laboratory conditions using standard test procedures. PRS probe nutrients are reported as micrograms/10cm2/time.
The TREND (PSRF)- Terrestrial Ecosystems project initiated a landscape-scale monitoring transect along the Adelaide Geosyncline region in southern Australia, initially spanning approximately 550 km. The aim was to examine spatial drivers of species composition and to isolate the influence of climate on whole vegetation community composition and therefore inform on-going monitoring of the impact of climate change. Specific questions were: 1. What are the most important spatial drivers of species and phylogenetic composition along landscape-scale environmental gradients? 2. Can the answer to Question 1. inform selection of suitable spatial analogues for climate change? 3. How can a framework for assessing spatial drivers be used to monitor and interpret shifts in species composition due to climate change? The dataset consists of site and species records (see attachments) for plots established along the Adelaide Geosyncline for the TREND project. Data consist of vascular plant species composition (presence-abundance/absence) within 900m<sup>2</sup> plots plus site data, including aspect and soil properties. Data have been used to analyze changes in composition with geographic and environmental differences and as a baseline for monitoring.
Dataset for abiotic and biotic responses to woody debris additions in restored old fields in a MBACI experiment
Experimental sites were established in the northern wheat-growing district of western Australia (Lat -29.66°, Long 116.18°) in August 2017, and monitored through to November 2019. We selected five planted old field sites with similar soil types and vegetation composition. Old fields were planted with York gum (Eucalyptus loxophleba Benth.) and dominant shrubs as understorey. At the time of sampling in 2017, vegetation age ranged from 8–13 years and distance from remnant measured 279 m (± 162 m). We established two control and two treatment plots, each measuring 5 m x 5 m, in the interrows of five planted old field sites. Both treatments were randomly assigned to plots within each site. Between August and early November 2017, we measured a total of 30 response variables at each of the control and treatment plots. Response variables included soil physical and chemical properties (bulk density, penetration resistance, soil moisture, nitrogen and carbon pools), microbial biomass, decomposition rate of roiboos and green tea as per the standardized Tea Bag Index (TBI) protocol, herbaceous vegetation cover and richness, and ant abundance and richness, as well as abundance and richness of ant functional groups.