Soil water-holding capacity and monodominance in Southern Amazon tropical forests

Background and aims: We explored the hypothesis that low soil water-holding capacity is the main factor driving the monodominance of Brosimum rubescens in a monodominant forest in Southern Amazonia. Tropical monodominant forests are rare ecosystems with low diversity and high dominance of a single tree species. The causes of this atypical condition are still poorly understood. Some studies have shown a relationship between monodominance and waterlogging or soil attributes, while others have concluded that edaphic factors have little or no explanatory value, but none has accounted for soil-moisture variation other than waterlogging. This study is the first to explicitly explore how low soil water-holding capacity influences the monodominance of tropical forests. Methods: We conducted in situ measurements of vertical soil moisture using electrical resistance collected over 1 year at 0–5; 35–40 and 75–80 cm depths in a B. rubescens monodominant forest and in an adjacent mixed-species forest in the Amazon-Cerrado transition zone, Brazil. Minimum leaf water potential (Ψmin) of the seven most common species, including B. rubescens, and soil water-holding capacity for both forests were determined. Results: The vertical soil moisture decay pattern was similar in both forests for all depths. However, the slightly higher water availability in the monodominant forest and Ψmin similarity between B. rubescens and nearby mixed forest species indicate that low water-availability does not cause the monodominance. Conclusions: We reject the hypothesis that monodominance of B. rubescens is primarily determined by low soil water-holding capacity, reinforcing the idea that monodominance in tropical forests is not determined by a single factor

Maintaining the strategic edge: the defence of Australia in 2015

The recent and continuing changes in Southeast Asia - the economic calamity in 1997-98, the overthrow of President Soeharto's New Order and the tenuous establishment of democracy, and the horrific circumstances of East Timor's independence - have disturbed Australia's security situation more seriously than anything since the 1960s, when Australia was at war (albeit covertly) with Indonesia in Borneo and had a task force in Vietnam. The rate of technological change is also unprecedented, especially in the area of information technology (IT) and its manifold applications, promising a revolution in military affairs (RMA), some aspects of which are very attractive for Australian defence planning. At the same time, the Australian Defence Force (ADF) faces the imminent prospect of 'block obsolescence' - when major platforms such as the F/A-18 Hornet multi-role fighter aircraft, the F-111 strike fighters, the P-3C Orion long-range maritime patrol aircraft, and all of the navy's surface combatants, will need to be replaced (or their tasks foregone). Addressing these issues will require the development of a sound appreciation of Australia's security environment, and of clear and coherent strategic guidance for defence force planning. The purpose of this volume is to assist and inform these processes

Actions:The return of urban guerrillas

In this opening chapter of the first part of this book, I analyse the current threat of terrorism as regards the safety and security of our cities and our open societies. The themes of vulnerability of these open societies, and the criticality of certain parts of urban infrastructures the existence and smooth functioning of which we tend to take for granted form the backdrop to the discussion of the growing threat to our cities, moving from assassination-style attacks of, for example, the German Red Army Faction and the bombing attacks of the IRA against the City of London to mass-casualty attacks targeting our Western way of life and our ‘sinful’ cities as such by actors associated with Al Qaeda and ISIS/Daesh on the one hand and attacks by way of weaponizing ‘mundane objects’ such as cars, vans, trucks or simple knifes for that matter. My main argument here is that our growing urban sprawls now provide terrorists with an ‘urban jungle’ Marighella could only dream of when he wrote his Minimanual of the Urban Guerrilla in the late 1960s.</p

T1 difficulty affects the AB: Manipulating T1 word frequency and T1 orthographic neighbor frequency

Colored target words were presented with distractor nonwords in a rapid serial visual presentation (RSVP) task. In Experiment 1, the attentional blink (AB) effect on T2 accuracy was larger when T1 was a difficult (low-frequency) word than when it was a high-frequency word. In Experiment 2 the effect of T1 frequency on the AB was replicated in a between-participants design, and the frequency of T1's one-letter different neighbors (e.g., case, bare, for care) interacted with T1 frequency in its effects on T2 accuracy. Experiment 3 confirmed the effect of T1 frequency over 6\ua0T1-T2 lags. The effects of T1 characteristics were sensitively assessed in the AB and were more consistent with resource depletion theories than control-process accounts