Global biodiversity gradients are generally expected to reflect greater species replacement closer to the equator. However, empirical validation of global biodiversity gradients largely relies on vertebrates, plants, and other less diverse taxa. Here we assess the temporal and spatial dynamics of global arthropod biodiversity dynamics using a beta-diversity framework.
View Article and Find Full Text PDFDeadwood is a large global carbon store with its store size partially determined by biotic decay. Microbial wood decay rates are known to respond to changing temperature and precipitation. Termites are also important decomposers in the tropics but are less well studied.
View Article and Find Full Text PDFIn 2020, the Australian and New Zealand flux research and monitoring network, OzFlux, celebrated its 20 anniversary by reflecting on the lessons learned through two decades of ecosystem studies on global change biology. OzFlux is a network not only for ecosystem researchers, but also for those 'next users' of the knowledge, information and data that such networks provide. Here, we focus on eight lessons across topics of climate change and variability, disturbance and resilience, drought and heat stress and synergies with remote sensing and modelling.
View Article and Find Full Text PDFTasmania experienced a protracted warm spell in November 2017. Temperatures were lower than those usually characterising heatwaves. Nonetheless the warm spell represented an extreme anomaly based on the historical local climate.
View Article and Find Full Text PDFThe amount of carbon stored in deadwood is equivalent to about 8 per cent of the global forest carbon stocks. The decomposition of deadwood is largely governed by climate with decomposer groups-such as microorganisms and insects-contributing to variations in the decomposition rates. At the global scale, the contribution of insects to the decomposition of deadwood and carbon release remains poorly understood.
View Article and Find Full Text PDFGross primary productivity (GPP) of wooded ecosystems (forests and savannas) is central to the global carbon cycle, comprising 67%-75% of total global terrestrial GPP. Climate change may alter this flux by increasing the frequency of temperatures beyond the thermal optimum of GPP (T ). We examined the relationship between GPP and air temperature (Ta) in 17 wooded ecosystems dominated by a single plant functional type (broadleaf evergreen trees) occurring over a broad climatic gradient encompassing five ecoregions across Australia ranging from tropical in the north to Mediterranean and temperate in the south.
View Article and Find Full Text PDFGlobally, forests are facing an increasing risk of mass tree mortality events associated with extreme droughts and higher temperatures. Hydraulic dysfunction is considered a key mechanism of drought-triggered dieback. By leveraging the climate breadth of the Australian landscape and a national network of research sites (Terrestrial Ecosystem Research Network), we conducted a continental-scale study of physiological and hydraulic traits of 33 native tree species from contrasting environments to disentangle the complexities of plant response to drought across communities.
View Article and Find Full Text PDFThe ratio of leaf intercellular to ambient CO (χ) is modulated by stomatal conductance (g ). These quantities link carbon (C) assimilation with transpiration, and along with photosynthetic capacities (V and J ) are required to model terrestrial C uptake. We use optimization criteria based on the growth environment to generate predicted values of photosynthetic and water-use efficiency traits and test these against a unique dataset.
View Article and Find Full Text PDFTimber harvest can adversely affect forest biota. Recent research and application suggest that retention of mature forest elements (retention forestry), including unharvested patches (or aggregates) within larger harvested units, can benefit biodiversity compared to clearcutting. However, it is unclear whether these benefits can be generalized among the diverse taxa and biomes in which retention forestry is practiced.
View Article and Find Full Text PDFFungal diversity of Australian eucalypt forests remains underexplored. We investigated the ectomycorrhizal (EcM) fungal community characteristics of declining temperate eucalypt forests in Tasmania. Within this context, we explored the diversity of EcM fungi of two forest types in the northern highlands in the east and west of the island.
View Article and Find Full Text PDFEcosystem monitoring networks aim to collect data on physical, chemical and biological systems and their interactions that shape the biosphere. Here we introduce the Australian SuperSite Network that, along with complementary facilities of Australia's Terrestrial Ecosystem Research Network (TERN), delivers field infrastructure and diverse, ecosystem-related datasets for use by researchers, educators and policy makers. The SuperSite Network uses infrastructure replicated across research sites in different biomes, to allow comparisons across ecosystems and improve scalability of findings to regional, continental and global scales.
View Article and Find Full Text PDFIn increasingly fragmented landscapes, it is important to understand how mature forest affects adjacent secondary forest (forest influence). Forest influence on ecological succession of beetle communities is largely unknown. We investigated succession and forest influence using 235 m long transects across boundaries between mature and secondary forest at 15 sites, sampling a chronosequence of three forest age classes (5-10, 23- 29, and 42-46 years since clear-cutting) in tall eucalypt forest in Tasmania, Australia.
View Article and Find Full Text PDFDisturbance associated with severe wildfires (WF) and WF simulating harvest operations can potentially alter soil methane (CH4 ) oxidation in well-aerated forest soils due to the effect on soil properties linked to diffusivity, methanotrophic activity or changes in methanotrophic bacterial community structure. However, changes in soil CH4 flux related to such disturbances are still rarely studied even though WF frequency is predicted to increase as a consequence of global climate change. We measured in-situ soil-atmosphere CH4 exchange along a wet sclerophyll eucalypt forest regeneration chronosequence in Tasmania, Australia, where the time since the last severe fire or harvesting disturbance ranged from 9 to >200 years.
View Article and Find Full Text PDFThe world has made enormous progress in improving child survival since 1990, reducing the under-five mortality rate by nearly half from 90 to 46 deaths per 1,000 live births in 2013. Currently, the global under-five mortality rate is falling faster than at any other time over the past two decades. Yet, progress is insufficient to meet the Millennium Development Goal 4 (MDG 4) which calls for reducing the under-five mortality rate by two-thirds between 1990 and 2015.
View Article and Find Full Text PDFInt J Environ Res Public Health
August 2014
International monitoring of drinking water and sanitation shapes awareness of countries' needs and informs policy, implementation and research efforts to extend and improve services. The Millennium Development Goals established global targets for drinking water and sanitation access; progress towards these targets, facilitated by international monitoring, has contributed to reducing the global disease burden and increasing quality of life. The experiences of the MDG period generated important lessons about the strengths and limitations of current approaches to defining and monitoring access to drinking water and sanitation.
View Article and Find Full Text PDFA recent UNICEF report Committing to Child Survival: A Promise Renewed Progress Report 2013 presents a comprehensive analysis of levels and trends in child mortality and progress towards MDG 4. The global under-five mortality rate has been cut nearly in half (47%) since 1990. However, during this same period, 216 million children are estimated to have died before their fifth birthday.
View Article and Find Full Text PDFConsiderable progress has been made in reducing maternal, newborn, and child mortality worldwide, but many more deaths could be prevented if effective interventions were available to all who could benefit from them. Timely, high-quality measurements of intervention coverage--the proportion of a population in need of a health intervention that actually receives it--are essential to support sound decisions about progress and investments in women's and children's health. The PLOS Medicine "Measuring Coverage in MNCH" Collection of research studies and reviews presents systematic assessments of the validity of health intervention coverage measurement based on household surveys, the primary method for estimating population-level intervention coverage in low- and middle-income countries.
View Article and Find Full Text PDFThe possible drivers and implications of an observed latitudinal cline in disease resistance of a host tree were examined. Mycosphaerella leaf disease (MLD) damage, caused by Teratosphaeria species, was assessed in five Eucalyptus globulus (Tasmanian blue gum) common garden trials containing open-pollinated progeny from 13 native-forest populations. Significant population and family within population variation in MLD resistance was detected, which was relatively stable across different combinations of trial sites, ages, seasons and epidemics.
View Article and Find Full Text PDFBackground: Infant and young child feeding is critical for child health and survival. Proportion of infants 0-5 months who are fed exclusively with breast milk is a common indicator used for monitoring and evaluating infant and young child feeding in a given country and region. Despite progress made since 1990, a previous review in 2006 of global and regional trends found improvement to be modest.
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