Ambitious plans for the world's largest seed bank for wild plant species are now a reality with the recent opening of the Millenium Seed Bank (MSB) at Wakehurst Place in southern England under the direction of the world-famous Royal Botanic Gardens at Kew near London. With the infrastructure in place, one of the key goals for the coming years is to collect seed from a substantial proportion of ...

The plants, grown in the soils around a Fuel Holding Depot of the Nigerian National Petroleum Corporation, Ibadan, Oyo state, Nigeria have been investigated in this research in terms of their density and species composition so that the impact of contamination by petroleum products on soil seed banks could be determined. The study has used designated plots (25m by 25m) in a site, contaminated by...

Lindera melissifolia (Walter) Blume, or pondberry, is federally listed as an endangered shrub and grows in warm, humid lowland forests of seven states in the southeastern United States. e dioecious plants usually form clonal colonies as a result of rhizome sprouting. Although L. melissifolia can annually produce many bright red spicy scented drupes, information on reproduction of the species i...

Cheatgrass (Bromus tectorum L.) is a winter annual weed that presents a serious obstacle to rangeland restoration in the Intermountain West. The objective of this study was to evaluate factors regulating the size and persistence of cheatgrass carryover seed banks on semiarid sites in western Utah. We prevented current-year seed production in each of four habitats, then tallied emerging seedling...

The accumulation of seeds in the soil (the seedbank) can set the template for the early regeneration of habitats following disturbance. Seed dispersal is an important factor determining the pattern of seed rain, which affects the interactions those seeds experience. For this reason, seed dispersal should play an important role in structuring forest seedbanks, yet we know little about how that h...

Population dynamics tries to explain in a simple mechanistic way the variations of the size and structure of biological populations. In this dissertation we use mathematical modeling and analysis to study the various aspects of the dynamics of plant populations and their seed banks. In Chapter 2 we investigate the impact of structural model uncertainty by considering different nonlinear recruit...

Do bacterial taxa demonstrate clear endemism, like macroorganisms, or can one site's bacterial community recapture the total phylogenetic diversity of the world's oceans? Here we compare a deep bacterial community characterization from one site in the English Channel (L4-DeepSeq) with 356 datasets from the International Census of Marine Microbes (ICoMM) taken from around the globe (ranging from...

We present a mathematical framework that combines extinction-colonization dynamics with the dynamics of patch succession. We draw an analogy between the epidemiological categorization of individuals (infected, susceptible, latent and resistant) and the patch structure of a spatially heterogeneous landscape (occupied-suitable, empty-suitable, occupied-unsuitable and empty-unsuitable). This appro...