Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

La mise en place de toitures vertes d’intérêt écologique constitue un des outils permettant de soutenir le réseau des infrastructures vertes. En effet, les conditions abiotiques des toitures vertes extensives s’assimilant à celles des pelouses calcicoles mésoxériques à xériques, les toitures pourraient supporter des habitats analogues à ces milieux.
Deux études ont été menées en parallèle dans le cadre de ce travail. L’objectif était de caractériser les effets de la profondeur et de la nature du substrat ainsi que des conditions microclimatiques sur les communautés végétales inspirées des pelouses calcicoles sur toiture verte extensive.
Pour ce faire, deux dispositifs expérimentaux ont été suivis.
Le premier, en bacs, simule la réponse des toitures végétales à deux modalités de nature de substrat et trois modalités de profondeur. Un cortège de 22 espèces, inspiré des associations majeures des pelouses calcicoles belges, y a été semé le 27 avril 2017.
Le second, sur toit, teste deux modalités de profondeur de substrat ainsi que les effets des conditions microclimatiques associées à l’intensité de l’ensoleillement sur la composition spécifique. Le semis des 29 espèces sélectionnées y a été réalisé le 5 octobre 2017.
La profondeur de substrat et l’intensité de l’ensoleillement influencent significativement les communautés végétales des toits. En effet, les parcelles plus profondes et moins exposées arborent des communautés végétales plus riches et à plus grande emprise spatiale. La nature de substrat n’influence pas significativement le développement des espèces.
Les conditions abiotiques des toitures sont suffisamment assimilables à celles des pelouses calcicoles pour permettre le bon développement de certaines de ses espèces caractéristiques. Les communautés végétales des toitures extensives présentent toutefois une richesse spécifique et un couvert végétal moindres en comparaison aux habitats naturels. De plus, les espèces spécialistes des milieux à régime hydrique pauvre ne constituent pas les espèces structurantes des toits. Ce sont au contraire, les espèces généralistes, mésoxérophiles et mésophiles qui caractérisent les associations des toitures. Ces résultats suggèrent que les mélanges pour toiture verte peuvent s’étendre dans une certaine mesure à d’autres habitats et espèces moins spécifiques. Green roofs of ecological interest are a tool to support the network of green infrastructures. Indeed, abiotic conditions of extensive green roofs approach those of meso-xeric to xeric calcareous grasslands. Consequently, such roofs could host analogous habitats to these environments. As part of this master’s thesis, two studies were conducted simultaneously. The objective was to characterize the effects of substrate nature, substrate depth, and microclimatic conditions on the plant communities, inspired by the calcareous grasslands, on extensive green roofs. To achieve this, two experimental setups were used.
First, containers were used to simulate the response of green roofs to substrate of two types of nature and three types of depth. A selection of 22 species, inspired by major associations of Belgian calcareous grasslands, was sown on April 27th 2017.
Secondly, effects of substrate of two types of depth, and microclimatic conditions, associated with the intensity of sunlight, were tested on actual roofs’ specific composition. Seeding of the 29 selected species was conducted on October 5th 2017.
The depth of the substrate and the sunlight intensity significantly influence roofs’ plant communities. Indeed, deeper and less exposed plots show richer plant communities with greater spatial reach. The nature of the substrate does not significantly influence the development of the selected species.
The abiotic conditions of the roofs are sufficiently similar to those of the calcareous grasslands to allow the good development of some of its characteristic species. Extensive roof plant communities, however, have a lower species richness and vegetation cover, when compared to natural habitats. In addition, species from water-scarce environments are not part of the roofs’ structural species. On the contrary, generalist, meso-xerophilious, and mesophilious species characterize the associations of roofs. These results suggest that green roofs’ composition may extend to other less specific habitats and species.

Toitures vertes extensives --- pelouses calcaires mésoxérophiles --- pelouses calcaires xérophiles --- nature du substrat --- profondeur de substrat --- conditions microclimatiques --- habitat analogue --- succès --- communautés végétales --- Extensive green roofs --- mesoxeric calcareous grasslands --- xeric calcareous grasslands --- substrate type --- substrate depth --- microclimatic conditions --- analogous habitat --- success --- plant communities --- Sciences du vivant > Sciences de l'environnement & écologie

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Droughts are one of the main extreme meteorological, and hydrological phenomena, which influence both the functioning of ecosystems, and many important sectors of human economic activity. Throughout the world, various direct changes in meteorological, and climatic conditions, such as: air temperature, humidity, and evapotranspiration can be observed. They have a significant influence upon the shaping of the phenomenon of drought. Land cover and land use can also be indirect factors influencing evapotranspiration, and, by the same token, the water balance in the water catchment area. They can also influence the course of the process of the drought. The observed climate change, manifested mainly by increases in temperature, in turn, influencing evapotranspiration, may cause intensification in terms of both the degree and frequency of droughts. Droughts related to changes in the hydrological regime, and to the decrease in water resources. Its results can be observed in various sectors, related, among others, to a demand for water for people, agriculture and the Industry. It can also prove problematic for water ecosystems. To reflect the aforementioned information, a reasonable drought risk management is indispensable in order to ease the water demand related problems in various sectors of human activity. This book presents original research on various drought indicators, modern measurement techniques used, among others, for monitoring and predicting droughts, drought indicator trends, the impact of insufficient precipitation on human activity in the context of climate change, and examples of modern solutions devised to prevent water shortages.

extensive green roofs --- climate change --- summer drought --- urban vegetation --- phytomass --- fertilizer --- biodiversity --- blue green infrastructure --- pan evaporation --- ANN --- WANN --- SVM-RF --- SVM-LF --- Pusa station --- drought --- SPI --- run theory --- Sen’s estimator --- Mann–Kendall --- Wadi Cheliff Basin --- water stress --- soil moisture --- atmospheric evaporative demand --- eddy covariance --- gross primary productivity --- meteorological drought --- agricultural drought --- atmospheric circulation --- elementary circulation mechanism (ECM) --- information entropy --- atmospheric blocking --- hydrological drought --- trends --- central Poland --- lotic systems --- refuge habitats --- fish --- risk management --- forecasting --- ARIMA --- Standardized Precipitation Evapotranspiration Index (SPEI) --- mitigation --- atmospheric drought --- forest drought --- Carpathian Mts. --- beech --- vertical climate zones --- Copernicus Sentinel-1 --- electrical resistivity tomography --- expansive clay --- InSAR --- shrink-swell risk --- SMOS surface soil moisture --- wavelet analysis --- precipitation --- precipitation deficit --- climatic water balance --- n/a --- Sen's estimator --- Mann-Kendall