The presence of permafrost in Poland north of the line indicating the maximum ice extent of the Vistulian (Weichselian) glaciation after retreat of the land-ice cap has been a subject of debate for a long time. Investigations in an area at the line of the maximum ice extent of the Pomeranian phase prove that permafrost existed, indeed, after the ice retreat. This conclusion is drawn on the basis of morphological data (the presence of oriented kettle holes), sedimentological data (the nature of the infilling of the kettle holes) and pedological data (permafrost-affected horizons in soil profiles). It appears that the permafrost mostly developed in the ice-free zone that appeared after the retreat of the land-ice cap, but it is likely that some relict permafrost that had originated earlier in front of advancing ice was also still present. The landscape of northern Poland owes its relief partly to the Late Glacial permafrost.

Geomorphology as a scientific discipline has underwent major developments since the mid 20th century. From its original descriptive nature aiming to understand landscape evolution, it developed towards a more process-based oriented discipline. To a large extent this evolution followed a quantitative approach whereby modelling becomes more and more important. A schism between applied or engineering geomorphology and system-based geomorphology aiming at understanding landscape change emerges in the 1950-1960's. Only at the end of the 20th century – early 21st century, integration of quantitative field-based approaches on longer term issues of landscape evolution with numerical modelling emerges. This is particularly true for the Holocene for which the importance of human impact on geomorphic processes and landforms became acknowledged. With respect to landscape evolution on much longer timescales, the development of tectonic geomorphology becomes apparent. In this paper, some evolution of ideas and trends within geomorphology with respect to understanding landscape dynamics are summarised and put into the career perspective of Jef Vandenberghe.

The state of river channels and their riparian zones in terms of geomorphology and vegetation has a significant effect on water and sediment transport in headwater catchments. High roughness in natural rivers due to vegetation and geomorphological attributes generate drag on flowing water. This drag will slow water discharge, which in turn influences the sediment dynamics of the flow. The impacts of changes in the management of rivers and their riparian zone (either by catchment managers or river restoration plans) impacts both up- as well as downstream reaches, and should be assessed holistically prior to the implementation of these plans.

To assess the river's current state as well as any possible changes in geomorphology and vegetation in and around the river, effective approaches to characterise the river are needed. In this paper, we present a practical approach for making detailed surveys of relevant river attributes. This methodology has the benefit of being both detailed – describing river depth, width, channel morphology, erosive features and vegetation types – but also being practical in terms of time management. This is accomplished by identifying and describing characteristic benchmark reaches (typical sites) in detail against which the remainder of the river course can be rated. Using this method, a large river stretch can be assessed in a relatively short period while still retrieving high quality data for the total river course. In this way, models with high data requirements for assessing the condition of a river course, can be parameterised without major investments on field surveys.

In a small headwater catchment (23 km2) in southwestern Poland, this field methodology was used to retrieve data to run an existing model (HEC-GeoRAS) which can assess the impact of changes in the riparian and channel vegetation and channel management on sedimentation processes and stream flow velocity. This model determines the impact of channel morphology and in-channel and riparian vegetation on stream flow and sediment transport. Using four return periods of flooding (2, 10, 20 and 100 years), two opposing channel management / morphology scenarios were run; a natural channel and a fully regulated channel. The modelling results show an increase in the effect of riparian vegetation / geomorphology with an increase in return period of the modeled peak discharge. More natural channel form and increased roughness reduces the stream flow velocity due to increasing drag from flow obstructions (vegetation and channel morphological features). The higher the flood water stage, the greater the drag due to vegetation on the floodplains of natural river reaches compared to channelised sections. Slower flow rates have an impact on sediment mobilisation and transport in the river.

Radiocarbon dating of peat has its intrinsic problems. This is often caused by mobile organic fractions. For the Weichselian Pleniglacial, another methodological problem arises: the limit of the 14C dating method. This is discussed in terms of bulk (i.e. non-selected material, generally dated conventionally) vs AMS (i.e. selected botanical remains) dates, contamination, background and calibration, guided by a series of peat samples from the Belgian/Dutch border.

Multi-disciplinarity and multi-proxy approaches are necessary to understand the processes in complex earth systems. However, unlimited and uncontrolled multi-proxy-correlations may be risky. A number of case studies illustrate the potential pitfalls when the processes that drive the individual proxies have no common causal significance or dating is not precise enough. Crossing thresholds at different levels and delay times may also be factors that hamper direct correlations of proxies. Multi-proxy analysis of the intrinsic relationships between proxies in a system is the primary task before any correlation should be made.

This paper sketches the historical common grounds of economics and earth sciences from their roots as scientific disciplines in the period of Enlightenment, and from a much earlier not necessarily scientifical commonality in the economic dependency of early societies on the prevalence of natural resources on the surface of the earth. It proceeds by stressing the commonality of the two disciplines in being empirical and positivistically mechanistic, without ignoring the major socio-cultural rift that occurs between their respective practitioners. The argument is put forward that societal problems, whether global or local, are often not straightforward and easily solved with the tools of a single discipline, and a plea is made for the combination of earth sciences and economics as candidates for a potent multi-disciplinary combination. Briefly, the BSc curriculum in Earth Sciences and Economics is justified and an accompanying research agenda is highlighted that starts from an empirical quantification of ecosystem services at the landscape scale of catchments.