WHITE,VEINED MARBLE FROM ROMAN AMMAIA (PORTUGAL): PROVENANCE AND USE

A multimethod approach using petrography and strontium (Sr) isotopic analysis was applied to determine the geological source of 17 marble artefacts from the Roman town of Ammaia (Portugal). All samples are calcitic, with dolomite, quartz and muscovite as accessory minerals. The marbles are characteristically medium‐grained with a maximum grain size (MGS) between 0.98 mm and 1.82 mm, have a heteroblastic texture, and have curved to embayed calcite grain boundaries. ⁸⁷Sr/⁸⁶Sr values of marble leachates range from 0.708488 to 0.708639. Comparison with Hispanic and Mediterranean marbles suggests the Estremoz Anticline as the most likely source for the Ammaia marble, especially for architectural marble. This hypothesis is supported by the geographical proximity of the Estremoz marble district and the long and expensive overland transport required for other marbles to reach Ammaia.     

Regional Planning in Queensland's Rangelands: Challenges and Prospects for Biodiversity Conservation

In Australia, the Commonwealth and State governments are increasingly devolving natural resource management (NRM) responsibilities to regional bodies. This move has led to the development of regional NRM plans. Native vegetation and biodiversity conservation, along with soil, pasture and water resources, are key components of the regional NRM plans in Queensland's extensive rangelands. This paper outlines and applies a set of criteria for evaluating the native vegetation and biodiversity content of accredited regional NRM plans for Queensland's rangelands. The evaluation showed considerable variation in the comprehensiveness of the information and knowledge base and management action targets among plans, including the poor articulation of impacts of excessive grazing pressure on biodiversity. The NRM plans lacked effective integration of natural resource, native vegetation and biodiversity conservation targets and actions. Several regions had too many biodiversity targets, many of which were poorly integrated. This is symptomatic of a limited understanding of rangelands as ecological systems and the lack of an integrated planning framework. We conclude regional NRM planning is not a ‘silver bullet’ for biodiversity conservation in the rangelands, but rather, it is the beginning of a long road to address complex, multi‐scale problems at a regional level.     

COMPUTER VISION‐BASED ORTHOPHOTO MAPPING OF COMPLEX ARCHAEOLOGICAL SITES: THE ANCIENT QUARRY OF PITARANHA (PORTUGAL–SPAIN)

Ancient quarries are intriguing archaeological sites, but their detailed recording is complex. This paper presents a cost‐effective approach to mapping of the Roman quarry site of Pitaranha (Portugal–Spain). First, aerial photographs were acquired using a radio‐controlled digital reflex camera attached to a Helikite, which allowed the acquisition of the necessary low‐altitude aerial footage in the very unstable wind conditions above the quarry. Using computer vision algorithms, the resulting set of photographs was semi‐automatically transformed into a Digital Surface Model (DSM) and a corresponding orthophotograph. Besides focusing on the acquisition and processing method, this paper evaluates the accuracy of the generated products. The orthophotograph proved to be satisfactorily accurate for 1:200 hard‐copy mapping.     

Deal or no deal: the outlook for agricultural land investment in Africa

Recent sharp increases in food prices have prompted some food-importing countries to promote the acquisition of farmland abroad as a strategy to secure food supplies at affordable prices. Businesses are recognizing new opportunities for strong returns from agricultural investment, including agri-food, biofuels and other agricultural commodities. Dubbed 'land grabs' in the press, large-scale land acquisitions have kindled much international debate, in which strong positions are taken on the impacts of such investments on the environment, rights, sovereignty, livelihoods, development and conflict at local, national and international levels. This article provides an analysis of this complex and shifting situation, focusing on Africa and drawing on quantitative inventories of land acquisitions in four countries and on a small sample of land deals. The article lays out key trends and drivers, and discusses the main features of international land deals before analysing the main risks and opportunities involved, focusing on implications for local, national and global food security. The article concludes by outlining practical steps to make the renewed momentum in agricultural investment work for development, and avoid the pitfalls of exacerbated political tensions.