From 1 - 10 / 14
  • Categories    

    1. Restoration of degraded landscapes has become increasingly important for conservation of species and their habitats owing to habitat destruction and rapid environmental change. An increasing focus for restoration activity are old-fields as agricultural land abandonment has expanded in the developed world. Studies examining outcomes of ecological restoration predominantly focus on vegetation structure and plant diversity, and sometimes vertebrate fauna. Fewer studies have systematically investigated effects of restoration efforts on soil chemical and biophysical condition or ground-dwelling invertebrates and there is limited synthesis of these data. 2. This dataset comprised data for a global meta-analysis of published studies to assess the effects on soil properties and invertebrates of restoring land that was previously used for agriculture. Studies were included if the site had been either cropped or grazed, restoration was either active (planting) or passive (abandonment, fencing) and if adequate data on soil chemical or physical properties or invertebrate assemblages were reported for restored, control (cropped/grazed) or reference sites. 3. The dataset includes 42 studies, published between 1994 and 2019 that met the inclusion criteria, covering 16 countries across all continents. More studies assessed passive restoration approaches than active planting, and native species were more commonly planted than exotic species.

  • Categories    

    In 1963, the Glen Canyon Dam, in Hite Utah was completed, creating the Lake Powell reservoir along the Colorado River. The water levels of Lake Powell peaked in 1983 and have declined since, releasing over-pressure on the underlying sediment. This release in over-pressure created mud volcanoes, structures along the shoreline made of cavities that allow fluid and gases to rise to the surface and escape. Green house gases including methane are released from these structures, and to better understand how development of natural wetlands can result in unintended increased levels of greenhouse gas emissions, we asked 1) how much of each gas is generated or and whether the amount of each gas is changing through time and 2) how are these gases forming in the subsurface? We first measured the amounts of carbon dioxide (CO2), methane (CH4), and air (N) in volcano gas samples collected in 2014, 2015, and 2016. We found that from 2014 through 2016, methane levels from these volcanoes fluctuated significantly. In 2016, we looked at the amounts of carbon and hydrogen isotopes in the methane, which told us the gas is generated from microorganisms feeding on organic matter and is released during water-level fluctuations. We looked at mud volcanoes only located along the Lake Powell marina delta in Hite, Utah. The data spans geological structures restricted to one marina delta.

  • Categories    

    <br>Hermitage Research Station (28&deg; 12’ S, 152&deg; 06’ E) situated near Warwick, is the site of a 33 year study of carbon cycling, storage and emissions in a southern Queensland winter cereal system. Mean annual temperature at the site is 17.5&deg;C and mean annual rainfall is 685&nbsp;mm. The soil is a Vertosol containing 65% clay, 24% silt, and 11% sand. Treatments at the trial included stubble burnt (SB), stubble retained (SR), conventional tillage (CT), no tillage (NT), nitrogen fertiliser added (NF) and no nitrogen fertiliser added (N0). It has provided guidance to farmers on optimising nitrogen use efficiency through fine tuning rates to meet crop need, e.g. delivering nitrogen when it is needed by the crop possibly using split applications and coated fertilisers with slower nutrient release profiles. Sourcing nitrogen from pulse crop and pasture was also studied as an option for meeting nitrogen needs with lower emissions and reduced cost.</br>

  • Categories    

    The record contains information on litterfall data collected from the dry sclerophyll forest, Samford Peri-Urban Site, South East Queensland from between 2011-2013. Data on plant litter weight, leaf carbon and nitrogen content are provided.

  • Categories    

    The record contains information on leaf chemistry studied on co-occurring tropical mountaintop restricted tree species from various mountaintop sites in Far North Queensland in 2019. Data on leaf stable carbon and nitrogen isotope concentrations, and elemental chemistry such as carbon, nitrogen, phosphorous, calcium, magnesium, potassium, sodium, copper, boron, sulfur, zinc and manganese are provided.

  • Categories    

    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.

  • Categories  

    The dataset accompanies the paper by Zemunik et al. (2016), which used the Jurien Bay dune chronosequence to investigate the changes in the plant community diversity and turnover in response to long-term soil development. The Jurien Bay chronosequence is located in the Southwest Australian biodiversity hotspot, in an area with an extremely rich regional flora. The dataset consists of both flora and soil data that allows all analyses presented in the paper (Zemunik et al. 2016) to be independently investigated. The dataset is an update to that previously supplied for a prior study (Zemunik et al. 2015; DOI 10.4227/05/551A3DDE8BAF8). The study used a randomised stratified design, stratifying the dune system of the chronosequence into six stages, the first three spanning the Holocene (to ~6.5 ka) and oldest spanning soil development from the Early to Middle Pleistocene (to ~2 Ma). Floristic surveys were conducted in 60 permanent 10 m × 10 m plots (10 plots in each of six chronosequence stages). Each plot was surveyed at least once between August 2011 and March 2012, and September 2012. To estimate canopy cover and number of individuals for each plant species within the 10 m × 10 m plots, seven randomly-located 2 m × 2 m subplots were surveyed within each plot. Within each subplot, all vascular plant species were identified, the corresponding number of individuals was counted and the vertically projected vegetation canopy cover was estimated. Surface (0-20 cm) soil from each of the 420 subplots was collected, air dried and analysed at the Smithsonian Tropical Research Institute in Panama, for a range of chemical and physical properties: total and resin soil phosphorus; total nitrogen and dissolved organic nitrogen; soil total and organic carbon; exchangeable calcium (Ca), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn) and sodium (Na); Mehlich-III extractable iron, magnesium, copper (Cu) and zinc (Zn); and pH (measured in H20 and CaCl2). Nutrient-acquisition strategies were determined from the literature, where known, and from mycorrhizal analyses of root samples from species with poorly known strategies. Most of the currently known nutrient-acqusition strategies were found in the species of the chronosequence. Previous studies in the Jurien Bay chronosequence have established that its soil development conforms to models of long-term soil development first presented by Walker and Syers (1976); the youngest soils are N-limiting and the oldest are P-limiting (Laliberté et al. 2012). However, filtering of the regional flora by high soil pH on the youngest soils has the strongest effect on local plant species diversity (Laliberté et al. 2014). The update involved modification to species names due to taxonomic changes and the inclusion of additional soil analyses, not present in Zemunik et al. (2015). The additional soil variables (additional to DOI 10.4227/05/551A3DDE8BAF8) were exchangeable Ca, K, Al, Mg, Mn and Na, measured for all 420 subplots; and Cu, Fe, Mn and Zn, extracted in Mehlich III solution, for each of the 60 plots. References Laliberté, E., Turner, B.L., Costes, T., Pearse, S.J., Wyrwoll, K.H., Zemunik, G. & Lambers, H. (2012) Experimental assessment of nutrient limitation along a 2-million-year dune chronosequence in the south-western Australia biodiversity hotspot. Journal of Ecology, 100, 631-642. Walker, T.W. & Syers, J.K. (1976) The fate of phosphorus during pedogenesis. Geoderma, 15, 1-19. Zemunik, G., Turner, B.L., Lambers, H. & Laliberté, E. (2015) Diversity of plant nutrient-acquisition strategies increases during long-term ecosystem development. Nature Plants 1, Article number: 15050, 1-4. Zemunik, G., Turner, B.L., Lambers, H. & Laliberté, E. (2016) Increasing plant species diversity and extreme species turnover accompany declining soil fertility along a long-term chronosequence in a biodiversity hotspot. Journal of Ecology.

  • Categories    

    This dataset contains leaf functional trait measurements describing leaf structure, chemistry and metabolism collected from the Warra Tall Eucalypt site, in summer 2012 and winter 2013.

  • Categories    

    This dataset contains leaf functional trait measurements describing leaf structure, chemistry and metabolism collected from the Calperum Mallee site, in 2013.

  • Categories    

    This dataset contains leaf functional trait measurements describing leaf structure, chemistry and metabolism collected from the Cumberland Plain site in 2014.