Master Thesis Online
From the species perspective: the contribution of a fine scale microtopography analysis for the conservation of alpine bryophytes
Theunissen, Kelly 
Promotor(s) :
Vanderpoorten, Alain
;
Collart, Flavien
Date of defense : 3-Sep-2024/6-Sep-2024 • Permalink : http://hdl.handle.net/2268.2/21045
Details
| Title : | From the species perspective: the contribution of a fine scale microtopography analysis for the conservation of alpine bryophytes |
| Translated title : | [fr] Du point de vue des espèces : contribution d’une analyse microtopographique à fine résolution pour la conservation des bryophytes alpines |
| Author : | Theunissen, Kelly
|
| Date of defense : | 3-Sep-2024/6-Sep-2024 |
| Advisor(s) : | Vanderpoorten, Alain
Collart, Flavien |
| Committee's member(s) : | Monty, Arnaud
Dufrêne, Marc
|
| Language : | English |
| Number of pages : | 66 |
| Keywords : | [en] bryophytes [en] SDM [en] microclimate [en] fine-resolution [en] Alps [en] models [en] microtopography [en] conservation [en] fine-scale [en] microvariables [en] species distribution models [en] in-situ measurements [en] microrefugia [fr] bryophytes [fr] SDM [fr] microclimat [fr] microtopographie [fr] fine résolution [fr] Alpes [fr] modèles [fr] conservation [fr] fine échelle [fr] microvariables [fr] modèle de distribution d'espèces [fr] mesures in-situ [fr] microrefuge |
| Discipline(s) : | Life sciences > Environmental sciences & ecology |
| Target public : | Researchers Professionals of domain Student General public |
| Institution(s) : | Université de Liège, Liège, Belgique |
| Degree: | Master en biologie des organismes et écologie, à finalité spécialisée en biologie de la conservation : biodiversité et gestion |
| Faculty: | Master thesis of the Faculté des Sciences |
Abstract
[en] Ecosystems and their biodiversity are under pressure from many threats. One way to predict
their impact on species is to use Species Distribution Models (SDM). However, most SDMs use
macroclimatic variables measured by weather stations 2 m above the ground and macro-scale
variables with a spatial resolution of 1 km, far larger than the area occupied by species.
Especially in the mountains, due to the complex topography, and for small species sensitive
to microclimatic variations, a large difference exists between the measured temperature and
that experienced by the species at their scale, which could lead to erroneous predictions in
SDMs.
This Master Thesis aims to i) compare the accuracy of the distribution of alpine
bryophytes sampled on two summits in Valais (Switzerland), between 3 SDMs based on
microtopographic variables: the first model using only 1 cm resolution variables, the second
using 2 m resolution variables and the last using both variables at 1 cm and 2 m resolution, ii)
predict, for the snow-free period, thanks to microtopographic variables at 1 cm or 2 m
resolution, the offset in mean temperature and relative humidity between those measured by
ERA-5 (spatial resolution of 31 km) and those measured by 71 loggers placed on the two
summits from September 2023 to June 2024.
The results show that i) the best model is the one using only microtopographic
variables at 2m resolution (AUC = 0.7 and TSS = 0.37), ii) the relative humidity offset, and
especially the temperature offset, are well predicted by microtopographic variables at 1 cm
resolution (R²=0.23 and R²=0.43, respectively, for the fixed effects).
Although this study could be extended in time and space, it supports the idea
that fine-scale variables can be used in SDMs, which is useful for identifying microrefugia in
mountains and thus could contrast the ability of alpine bryophyte to survive under climate
change.
File(s)
Document(s)
Theunissen_Kelly_memoire_BOE_aout2024.pdf
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