Search

Ocean–atmosphere climatic interactions, such as those resulting from El Niño Southern Oscillation (ENSO) are known to influence sea level, sea surface temperature, air temperature, and rainfall in the western Pacific region, through to the north-west Australian Ningaloo coast. Mangroves are ecologically important refuges for biodiversity and a rich store of blue carbon. Locations such as the study site (Mangrove Bay, a World Heritage Site within Ningaloo Marine Park and Cape Range National Park) are at the aridity range-limit which means trees are small in stature, forests small in area, and are potentially susceptible to climate variability such as ENSO that brings lower sea level and higher temperature. Here we explore the relationship between mangrove dieback, and canopy condition with climatic variables and the Southern Oscillation Index (SOI)—a measure of ENSO intensity, through remote sensing classification of Landsat satellite missions across a 29 year period at a north-west Australian site. We find that the SOI, and seasonal mean minimum temperature are strongly correlated to mangrove green canopy (as indicator of live canopy) area. This understanding of climate variations and mangrove temporal heterogeneity (patterns of abundance and condition) highlights the sensitivity and dynamics of this mangrove forest and recommends further research in other arid and semi-arid tropical regions at mangrove range-limits to ascertain the extent of this relationship.

Mangroves are integral to ecosystem services provided by the coastal zone, in particular carbon (C) sequestration and storage. Allometric relationships linking mangrove height to estimated biomass and C stocks have been developed from field sampling, while various forms of remote sensing has been used to map vegetation height and biomass. Here we combine both these approaches to investigate spatial patterns in living biomass of mangrove forests in a small area of mangrove in north-west Australia. This study used LiDAR data and Landsat 8 OLI (Operational Land Imager) with allometric equations to derive mangrove height, biomass, and C stock estimates. We estimated the study site, Mangrove Bay, a semi-arid site in north-western Australia, contained 70 Mg ha−1 biomass and 45 Mg C ha−1 organic C, with total stocks of 2417 Mg biomass and 778 Mg organic C. Using spatial statistics to identify the scale of clustering of mangrove pixels, we found that living biomass and C stock declined with increasing distance from hydrological features (creek entrance: 0–150 m; y = −0.00041x + 0.9613, R2 = 0.96; 150–770 m; y = −0.0008x + 1.6808, R2 = 0.73; lagoon: y = −0.0041x + 3.7943, R2 = 0.78). Our results illustrate a set pattern of living C distribution within the mangrove forest, and then highlight the role hydrologic features play in determining C stock distribution in the arid zone.

Este artículo contiene 9 páginas., “Blue carbon” ecosystems, which include tidal marshes, mangrove forests, and seagrass meadows, have large stocks of organic carbon (Corg) in their soils. These carbon stocks are vulnerable to decomposition and – if degraded – can be released to the atmosphere in the form of CO2. We present a framework to help assess the relative risk of CO2 emissions from degraded soils, thereby supporting inclusion of soil Corg into blue carbon projects and establishing a means to prioritize management for their carbon values. Assessing the risk of CO2 emissions after various kinds of disturbances can be accomplished through knowledge of both the size of the soil Corg stock at a site and the likelihood that the soil Corg will decompose to CO2., Support was provided by the CSIRO Coastal Carbon Biogeochemistry Cluster. We also acknowledge the support of The Oceans Institute of the University of Western Australia, the Global Change Institute of The University of Queensland, and the Australian Research Council (awards DE130101084 and LP160100242).

Ecological (poleward) regime shifts are a predicted response to climate change and have been well documented in terrestrial and more recently ocean species. Coastal zones are amongst the most susceptible ecosystems to the impacts of climate change, yet studies particularly focused on mangroves are lacking. Recent studies have highlighted the critical ecosystem services mangroves provide, yet there is a lack of data on temporal global population response. This study tests the notion that mangroves are migrating poleward at their biogeographical limits across the globe in line with climate change. A coupled systematic approach utilising literature and land surface and air temperature data was used to determine and validate the global poleward extent of the mangrove population. Our findings indicate that whilst temperature (land and air) have both increased across the analysed time periods, the data we located showed that mangroves were not consistently extending their latitudinal range across the globe. Mangroves, unlike other marine and terrestrial taxa, do not appear to be experiencing a poleward range expansion despite warming occurring at the present distributional limits. Understanding failure for mangroves to realise the global expansion facilitated by climate warming may require a focus on local constraints, including local anthropogenic pressures and impacts, oceanographic, hydrological, and topographical conditions.

A disproportionate focus of research to date has focussed on public transport (PT) opportunities available within the residential neighbourhood, despite the need to focus on origin and destination PT infrastructure. Furthermore, there are recommended maximum access distances of 400 m for lower quality PT services (e.g., bus) and 800 m for higher quality PT services (e.g., rail). This study investigates associations between commuting behaviours and distance to bus and rail stops from residence and workplace, and the PT access thresholds and densities in a sample of 238 employed adults drawn from the RESIDE study in Perth, Australia. Self-reported usual workplace travel mode was compared with objectively derived home to work commute distance, and distance to the nearest rail and bus stops from residence and workplace. Overall, 207 (87.0%) participants usually commuted to work by private motor vehicle (PMV), and 31 (13.0%) participants commuted by PT modes. Those who travelled to work using PT modes had longer commute distances, but had bus and rail stops located closer to their workplace compared with respondents who commuted using PMV modes. Compared with those only having proximate residential PT access, respondents who only had proximate workplace PT access (adjusted OR=11.57), or had both proximate residence and workplace PT access (adjusted OR=16.51) were substantially more likely to commute to work using PT modes. These findings highlight the importance of proximate PT infrastructure both near home and workplaces. People seemed willing to travel beyond the recommended bus and rail thresholds to access PT, provided it took them close to their workplace.

Este artículo contiene 10 páginas, 7 figuras, 1 tabla., Boating activities are one of the causes that threaten seagrass meadows and the ecosystem services they provide. Mechanical destruction of seagrass habitats may also trigger the erosion of sedimentary organic carbon (Corg) stocks, which may contribute to increasing atmospheric CO2. This study presents the first estimates of loss of Corg stocks in seagrass meadows due to mooring activities in Rottnest Island, Western Australia. Sediment cores were sampled from seagrass meadows and from bare but previously vegetated sediments underneath moorings. The Corg stores have been compromised by the mooring deployment from 1930s onwards, which involved both the erosion of existing sedimentary Corg stores and the lack of further accumulation of Corg. On average, undisturbed meadows had accumulated ~6.4 Kg Corg m−2 in the upper 50 cm-thick deposits at a rate of 34 g Corg m−2 yr−1. The comparison of Corg stores between meadows and mooring scars allows us to estimate a loss of 4.8 kg Corg m−2 in the 50 cmthick deposits accumulated over ca. 200 yr as a result of mooring deployments. These results provide key data for the implementation of Corg storage credit offset policies to avoid the conversion of seagrass ecosystems and contribute to their preservation., This work was supported by the ECU Faculty Research Grant Scheme and the CSIRO Flagship Marine & Coastal Carbon Biogeochemical Cluster (Coastal Carbon Cluster). RR was funded by the Australia Award Scholarship. PM was supported in part by a Gledden Visiting Fellowship awarded by the The University of Western Australia and the Generalitat de Catalunya (MERS 2014 SGR – 1356. AAO was supported by a PhD grant of Obra Social “la Caixa”. GAK was partly funded by an ARC Linkage grant (LP130100155).

Introduction: The built environment is increasingly recognised as being associated with health outcomes. Relationships between the built environment and health differ among age groups, especially between children and adults, but also between younger, mid-age and older adults. Yet few address differences across life stage groups within a single population study. Moreover, existing research mostly focuses on physical activity behaviours, with few studying objective clinical and mental health outcomes. The Life Course Built Environment and Health ( LCBEH ) project explores the impact of the built environment on self-reported and objectively measured health outcomes in a random sample of people across the life course. Methods and analysis: This cross-sectional data linkage study involves 15 954 children ( 0–15 years ), young adults ( 16–24 years ), adults ( 25–64 years ) and older adults ( 65+years ) from the Perth metropolitan region who completed the Health and Wellbeing Surveillance System survey administered by the Department of Health of Western Australia from 2003 to 2009. Survey data were linked to Western Australia's ( WA ) Hospital Morbidity Database System ( hospital admission ) and Mental Health Information System ( mental health system outpatient ) data. Participants’ residential address was geocoded and features of their ‘neighbourhood’ were measured using Geographic Information Systems software. Associations between the built environment and self-reported and clinical health outcomes will be explored across varying geographic scales and life stages. Ethics and dissemination: The University of Western Australia's Human Research Ethics Committee and the Department of Health of Western Australia approved the study protocol ( #2010/1 ). Findings will be published in peer-reviewed journals and presented at local, national and international conferences, thus contributing to the evidence base informing the design of healthy neighbourhoods for all residents.

Background Variations in ‘slope’ (how steep or flat the ground is) may be good for health. As walking up hills is a physiologically vigorous physical activity and can contribute to weight control, greater neighbourhood slopes may provide a protective barrier to weight gain, and help prevent Type 2 diabetes onset. We explored whether living in ‘hilly’ neighbourhoods was associated with diabetes prevalence among the Australian adult population. Methods Participants (≥25 years; n = 11,406) who completed the Western Australian Health and Wellbeing Surveillance System Survey (2003–2009) were asked whether or not they had medically-diagnosed diabetes. Geographic Information Systems (GIS) software was used to calculate a neighbourhood mean slope score, and other built environment measures at 1600 m around each participant’s home. Logistic regression models were used to predict the odds of self-reported diabetes after progressive adjustment for individual measures (i.e., age, sex), socioeconomic status (i.e., education, income), built environment, destinations, nutrition, and amount of walking. Results After full adjustment, the odds of self-reported diabetes was 0.72 (95% CI 0.55-0.95) and 0.52 (95% CI 0.39-0.69) for adults living in neighbourhoods with moderate and higher levels of slope, respectively, compared with adults living in neighbourhoods with the lowest levels of slope. The odds of having diabetes was 13% lower (odds ratio 0.87; 95% CI 0.80-0.94) for each increase of one percent in mean slope. Conclusions Living in a hilly neighbourhood may be protective of diabetes onset or this finding is spurious. Nevertheless, the results are promising and have implications for future research and the practice of flattening land in new housing developments.