Abstract
Australian rangelands ecosystems cover 81% of the continent but are understudied and continental-scale research has been limited in part by a lack of precise data that are standardised between jurisdictions. We present a new dataset from AusPlots Rangelands that enables integrative rangelands analysis due to its geographic scope and standardised methodology. The method provides data on vegetation and soils, enabling comparison of a suite of metrics including fractional vegetation cover, basal area, and species richness, diversity, and composition. Cover estimates are robust and repeatable, allowing comparisons among environments and detection of modest change. The 442 field plots presented here span a rainfall gradient of 129–1437 mm Mean annual precipitation with varying seasonality. Vegetation measurements include vouchered vascular plant species, growth form, basal area, height, cover and substrate type from 1010 point intercepts as well as systematically recorded absences, which are useful for predictive modelling and validation of remote sensing applications. Leaf and soil samples are sampled for downstream chemical and genomic analysis. We overview the sampling of vegetation parameters and environments, applying the data to the question of how species abundance distributions (SADs) vary over climatic gradients, a key question for the influence of environmental change on ecosystem processes. We found linear relationships between SAD shape and rainfall within grassland and shrubland communities, indicating more uneven abundance in deserts and suggesting relative abundance may shift as a consequence of climate change, resulting in altered diversity and ecosystem function. The standardised data of AusPlots enables such analyses at large spatial scales, and the testing of predictions through time with longitudinal sampling. In future, the AusPlots field program will be directed towards improving coverage of space, under-represented environments, vegetation types and fauna and, increasingly, re-sampling of established plots. Providing up-to-date data access methods to enhance re-use is also a priority.
Highlights
We demonstrate an application of the data to an important ecological question: Do plant species relative abundance patterns vary in a predictable way over continental-scale edaphic and climatic gradients? This is a key question for community assembly and predictive modelling applications because abundant species characterise communities and ecosystem function [14,15]
Field plots spanned a major continental gradient in Mean annual precipitation (MAP) of 129–1437 mm and Precipitation Seasonality ranging from the aseasonal interior deserts to the strongly seasonal tropical north and somewhat seasonal Mediterranean-climate south, with
We present the first collated dataset sampled by the AusPlots program, giving an overview of the breadth of sampling in terms of space, environments and vegetation
Summary
Rangelands make up 81% of the Australian landmass according to an accepted spatial definition encompassing inland and northern Australia, and consist of a variety of vegetation types in which the predominant land-use is extensive, low-intensity livestock grazing [1]. Many rangelands ecosystems are fragile and susceptible to large-scale change from both natural and anthropocentric events as well as species declines [4,5]. Despite their vast spatial extent and heterogeneity, Australia rangeland ecosystems as a whole remain relatively poorly studied [3], by no means without exceptions at local and regional scales [4,6]. For example, have been investigated somewhat more intensively than deserts [3,7,8] Baseline information on these systems is essential to determine their current condition, while ongoing surveillance monitoring can track changes occurring in these environments and inform management decisions in these areas [5]. Continental-scale ecological research across the Australian rangelands has been limited in part by a lack of data sources that are standardised between both repeated measurements (precision problem) and data collection efforts undertaken in different government jurisdictions (compatibility problem) in a spatially consistent manner
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call