Burial and turbulent transport by bioturbation: a 27‐year experiment in southeast Australia

In order to assess the net effect and relative importance of geomorphic processes at two natural woodland sites in southeast Australia, 100 small tiles were placed on the soil surface in 1979 and their movement was monitored over the course of nearly three decades. Rates of tile burial and other tile displacement were considerable but also markedly random, being largely inconsistent with expected patterns of displacement by orthodox creep and rainwash processes. This included substantial upslope displacement and burial depths that ranged from zero to 5 cm. We suggest that such turbulent transport in the topsoil has mostly been caused by the direct and indirect transfer of soil and clasts by animals and plants (i.e. bioturbation). In addition to direct evidence of biota interacting with tiles, the effectiveness of bioturbation at our sites has been well established and the overall tile burial rate of 0·25 to 0·4 mm yr^?1 is comparable to rates of surface mounding. Patterns of tile movement are generally consistent with soils‐geomorphic theory regarding the biomantle and bioturbation‐driven stonelayer formation, and provide further evidence that soil transfer and slope movement, in many situations, are markedly random and complex processes. Copyright © 2010 John Wiley & Sons, Ltd.     

Vulnerability of Himalayan transhumant communities to climate change

Climate change vulnerability depends on who you are, where you are and what you do. The indigenous communities who primarily depend on natural resources for subsistence livelihoods are among the first and most affected by climate change. Climate models have predicted pronounced warming in high altitude regions of the Himalayas. The transhumant communities of the Himalayas follow traditional lifestyles based on seasonal livestock rearing and subsistence agriculture. There is however, no information on how vulnerable transhumant communities are to climate change, and how vulnerability of transhumant herders differs across the mountainous areas of Nepal. Based on semi-structured interviews with transhumant herders and using the IPCC climate change vulnerability framework, this study assessed and compared the vulnerability of transhumant communities from three districts representing Eastern, Central and Western mountainous region of Nepal. The results showed that the livelihood vulnerability and the climate change vulnerability differ across sites; both of them having lowest index values in the Central region. The vulnerability dimensions viz. exposure, sensitivity and adaptive capacity are largely influenced by diversity in livelihood strategies, income sources and crops, and access to food, water and health facilities. The findings will inform the design of policies and programmes to reduce vulnerability and enhance adaptive capacity of indigenous communities in general and the transhumant communities of the Himalayas in particular.     

页岩储层成岩作用及其对储层脆性的影响 ——以渝西地区五峰组—龙马溪组深层页岩为例

页岩粒度细小、岩石致密、微观非均质性显著,在成岩作用改造下发育形成页岩气储层,成岩作用的研究可以为优质页岩储层发育机理提供依据.以渝西地区綦江观音桥剖面、南川泉浅1井、南川三泉剖面、大足Z-203井等代表性剖面、钻孔为例,通过X射线衍射、氩离子抛光—场发射扫描电镜、能谱、岩石薄片/光片显微观察、有机地球化学测试、力学特...     

Synergistic effects of diuron and sedimentation on photosynthesis and survival of crustose coralline algae

Effects of short-term exposure to sedimentation and diuron, separately and in combination, on the photophysiology and survival of crustose coralline algae (CCA) were examined in controlled time-course experiments, using pulse-amplitude modulation (PAM) chlorophyll fluorometry. These experiments indicated that the effects of sediments and diuron, when applied in isolation, were often reversible, with recovery time dependent upon sediment type and diuron concentration. Exposure to fine (<63 microm grain size), nutrient-rich estuarine sediments reduced effective quantum yields (Delta F/F(m')) of photosystem II in CCA species more than exposure to the same amount of fine (<63 microm grain size) calcareous sediments. Significant inhibition of photosynthesis (Delta F/F(m')) was also observed at diuron concentrations > or =2.9 microg L(-1). Fine estuarine sediments in combination with 0.79 microg L(-1) dissolved diuron, caused yields (Delta F/F(m')) to drop by 60% compared with controls after 24 h. The combined exposure to sediments and diuron also retarded recovery, thus Delta F/F(m') values were still only 60% of the controls after 9 days recovery in clean seawater. Mortality of CCA was observed in some fragments treated with combinations of sediment and diuron. Our results suggest that sediment deposition and exposure to diuron can negatively affect the photosynthetic activity of CCA, with sedimentation stress being significantly enhanced by the presence of trace concentrations of diuron.     

Measuring Spatial Variations in Sports Talent Development: the approach,methods and measures of ‘Talent Tracker’

Knowing where sports talent is produced is fundamental to identifying spatial factors in talent production and to assist with talent identification. This research develops spatial analysis methods—the ‘Talent Tracker’—to harness geographical information systems and identify regions that are over- and under-producing sports talent. The approach focuses on the professional Australian Football League (AFL), using data sourced from the AFL itself and other sources, to identify differences in regional ‘talent yield’ based on junior participation. Data from AFL draft records, informants and secondary sources identified the place of junior talent development for the 1290 players who were drafted and played at least one game of senior AFL football in the period 1997–2010. AFL national census data identified junior participation for 94 specified regions for the period 2002–09. AFL talent was assigned to these regions by using ArcGIS procedures, and the datasets synthesised to produce tables and maps of talent yield by participation for each of the 94 AFL regions. The results demonstrate the power of contemporary spatial analysis to open up new research methods for studies into sports talent production and identification. Clear spatial patterns emerge in talent yield at both the national and metropolitan scales. The results provide numerous avenues for further research to explore determining factors for the spatial patterns identified.