A sandy symphony

Abstract

The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license. More information can be found on the University of Groningen website: https://www.rug.nl/library/open-access/self-archiving-pure/taverneamendment.made (infra)structure (Feagin et al., 2005;. Furthermore, extreme climatic events, such as drought, storms or heat waves, could affect species interactions and subsequently ecosystem structure.To halt or reverse losses of ecosystems, and their vital functions, there is increasing interest in restoration of these ecosystems (Silliman et al., 2015;Temmink et al., 2020;van der Heide et al., 2021). There are some common restoration practices that happen in many vegetated coastal ecosystems, for example, increasing soil stability and sediment capture by creating structures such as brushwood check dams, and/or planting of ecosystem engineering vegetation (Bakker et al., 2002;Bridges et al., 2018;Ministerie V&W, 2000). While other practices are system specific, such as sand suppletion on sandy shores that are in an erosive state (Ministerie V&W, 2000). Classically, planting of vegetation is done in competition limiting arrays. However, in physically stressful environments neighbors can ameliorate physical stress, increasing survival success (Bertness & Hacker, 1994;Bruno et al., 2003). Over the last decades, inclusion of facilitation in restoration by clumped planting or mimicking larger plant patches gained interest Temmink et al., 2020). However, the success of these novel facilitationpromoting designs is context dependent (Fischman et al., 2019;Woods et al., 2023). The study system -Coastal dunesCoastal dunes occur along sandy shores, which make up about one-third of the world's coastline . They provide many services such as flood protection, drinking water and recreation (Martínez et al., 2007;. At locations with a positive sand budget and a dominant onshore wind direction, dune areas can expand and develop . This thesis focusses on the emergence and early development of the dunes, from beach to embryonic dunes, which depends on establishment and growth of dune grasses. Early dune development -Beach to foredunesGenerally, different developmental stages of dunes can be found on a cross-shore gradient from beach to dunes, corresponding to the biogeomorphic succession and primary succession gradient (Figure 1.1 & 1.3). Closest to the shore are bare beach areas that are frequently overwashed (i.e., the physical phase in biogeomorphic succession, Figure 1.1). From the sea, sediment ends up on the beach through currents and waves (Fredsoe & Deigaard, 1992;Swift, 1976). If the sediment dries