Recent trends of ecosystem services and human wellbeing in the Bangladesh delta

The report describes a preliminary assessment of the dynamical properties of the complex social-ecological system that defines the modern Bangladesh coastal zone. A range of historical data for ecosystem services and indicators of human wellbeing is used to describe the evolving trade-offs between ecosystem services and poverty and the evidence for past and future threshold changes. Since the 1980s, increasing GDP and per capita income mirror rising levels of food and inland fish production. As a result, the size of population below the poverty line has reduced by ~10% over the past 20 years. In contrast, non-food ecosystem services such as water availability, water quality and land stability have deteriorated. The extent to which the growing levels of food production and ecological deterioration are directly linked is difficult to judge, though conversion of rice fields to shrimp farms is almost certainly a factor in increasing soil and surface water salinity. An environmental Kuznets curve analysis suggests that the point at which growing economic wealth feeds back into effective environmental protection has not yet been reached for water resources. Trends in indicators of final ecosystem services and human wellbeing point to widespread non-stationary dynamics and slowly changing variables, declining resilience, and an increased probability of positive feedbacks driving systemic threshold changes/tipping points in the near future. Increasingly frequent cyclones and flood events increases the likelihood of threshold changes. The results will feed into simulation models and strategies that can define alternative and sustainable paths for land managemen

Palaeoclimate records from OIS 8.0-5.4 recorded in loess-palaeosol sequences on the Matmata Plateau, southern Tunisia, based on mineral magnetism and new luminescence dating

Mineral magnetic studies of loess–palaeosol sequences on the Matmata Plateau, southern Tunisia, coupled with a new chronology based on luminescence dating, confirm the presence of at least four phases of pedogenesis during the period 100–250 ka. Inter-site correlations between the reddened fersiallitic palaeosols confirms that, despite modern gullying processes, the records are regional and repeatable. The palaeosol magnetic signal is controlled by the formation of secondary ferrimagnetic minerals, which may be easily detected by magnetic susceptibility and frequency-dependent susceptibility measurements. Comparison of the magnetic record with global proxy climate records shows a correlation with loess–palaeosol sequences in China and the marine oxygen isotope (OI) record during stages 8.0–5.4. Preliminary attempts to infer palaeoprecipitation levels from modern analogues of soil magnetism-climate associations suggests that during the periods 100–120 ka and ~ 200 ka precipitation was >400 mm a?1, compared with modern precipitation <150 mm a?1