The coastal dunes show a great deal of variety in form, related to their sedimentation, their climatic setting (past and present), and ecological factors influencing their associated variations (Bird 1990). They are well known from many world coastlines (e.g. Bird, 1969; Hesp, 1984; 1987; Carter & Wilson, 1990; Arens, 1994; Nordstrom, 2000), and are well developed on sandy barriers where accumulation has or still occurs. Coastal dune ridges are structures built up by sand blowing along or across the beach.

Morphodynamic interactions in dunes are not well understood because the chaotic relief of many coastal dunes defies simple description (Carter, et al., 1990). The most important factors in dune development are aeolian processes, dune vegetation cover and winds. Dune plants stop sand being blown by wind from the beach. Plants break the wind speed causing sand accumulation and building up dunes (Bird, 1969; Hesp, 1987; Carter & Wilson, 1990; Arens, 1994; and others). Material deposition on beach covered by grasses can be 5-times greater than on foredune (Carter & Wilson, 1990). Investigation results say that 50 to 70% of sand is stopped by Ammophila sp. (e.g. Hesp, 1984; Arens, 1994).

Big storm surges destroying coast and dune ridges environment also have a considerable influence on their dynamics. Along many coast dunes threaten by storm surges are retreating. On many coast dunes are completely destroyed. We must understand that dunes are natural dykes preventing human infrastructure against floods. Investigations on natural processes as: dune morphodynamics and plant succession can give us knowledge to proper protection and dune management. These investigations are best to drive on natural, changeable on short distance coasts where we can observe different coastal processes and factors. Dune coast changes can be observed from relief profiles and vegetation transects across dunes. Plants are the indicators of ecological processes and soil processes also give information about dune stabilisation. Sediment is an indicator of aeolian and wave dynamics, direction of processes and budget of sand (on beach and dune). Wind is main factor of wave conditions and aeolian processes, so is deciding about sand budget, sediment dynamics and surface shaping. Waves can carry sand along coast and can shape beach and dunes during storm surges. Human is a new factor that play main role in dune and plant dynamics, but also influence on sediment dynamics on shore and off shore.

Contemporary dunes can also be destroyed by human activity. Settlement, tourism and development of economy may have negative impact (Carter, 1980; Pye, 1990; Isermann & Krisch, 1995; Piotrowska & Gos, 1995; Olsauskas, 1996). Nordstrom (2000) also mentioned overgrazing, deforestation, dune stabilisation, navigation improvements, water regulations, coast protection, tourism growth. Overgrazing and deforestation of coastal areas may lead to dune mobilisation (Nordstrom, 2000). On the other hand dune stabilisation by vegetation planting may cause the spreading alien species (Piotrowska & Stasiak, 1982). An increase of tourism and settlement causes activities of coast protection by sea walls, groins, dykes, nourishment, vegetation planting etc. Yet, dune management and seaside tourism development are other factors underlying the fact that dune morphology is changing (e.g. Carter, 1980; Pye, 1990; Nordstrom, 2000).

Heavy storms and human activity play a significant role in present day Polish coastal dunes' development. Polish well-urbanised coastal inland areas are endangered by an increasing sea level and increasing storm surges (Rotnicki & Borówka, 1990). Most of the Polish coastal habitats including dunes are also threatened by human activities (Piotrowska, 1995; Herbich & Warzocha, 1999).