Dynamics of vegetated landscapes since the end of the Little Ice Age: Analysis of plant colonization in proglacial areas.

• Main Author: Moreau, Myrtille
• Other Authors: Laboratoire de Géographie Physique et Environnementale (GEOLAB), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Université Clermont Auvergne (UCA)-Institut Sciences de l'Homme et de la Société (IR SHS UNILIM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), Université Blaise Pascal - Clermont-Ferrand II, Marie-Françoise André([e-mail])
• Format: Thesis
• Language: French
• Published: HAL CCSD 2005
• Subjects: proglacial area; plant colonization; GIS; DEM; vegetation sampling; Spitsbergen; marge proglaciaire; colonisation végétale; stratégies d'échantillonnage; SIG; MNT; Spitsberg; geo; envir; Arctic; Svalbard; Arctique*
• Online Access: https://tel.archives-ouvertes.fr/tel-00011178/file/Moreau_these.pdf; https://tel.archives-ouvertes.fr/tel-00011178

As a result of global climatic changes that followed the Little Ice Age, most Arctic glaciers are retreating and more areas are becoming available for plant colonization. Such a process can be observed on Svalbard in the frontal areas of five glaciers, located on the north western coastline and in the central part of the island. To determine the relationship between retreating glacial fronts and plant colonization processes, systematic releves are normally utilized. The resulting data usually indicate that time since glacial retreat is the primarily determining of vegetation evolution in terms of physiognomy and floristic composition. Although the floristic sequence is the same from the early pioneer stages to later mature ones, we found that this process is neither homogeneous nor explicitly time dependent. For example, environmental position, such as changes in micro-topographic relief, may also be an important factor in determining variation in the colonization process and can interfere with the normal time dependent colonization process. Within one proglacial area we observed floristic variation between different micro-topographic environments utilizing releves and a digital elevation model with a 2 m spatial resolution. This allowed us to examine floristic changes along both temporal (time from glacial retreat) and spatial (micro-topographic relief) scales. Using a probabilistic model, we were able to map the temporal and spatial effects on plant colonization in these glacial forelands and produce new landscape nomenclature to describe them. Sous l'effet du réchauffement climatique postérieur au Petit Âge Glaciaire, la fonte des glaciers arctiques a libéré de nouveaux espaces conquis ensuite par la végétation. Le phénomène est bien marqué au Spitsberg où la présente étude est conduite. Celle-ci concerne les marges de cinq glaciers, localisées sur la façade nord occidentale et dans le centre de l'île. Une première analyse a été conduite par relevés floristiques systématiques permettant de mettre en ...