Mathematical modelers hardly have sound knowledge of biological systems
they intend to explore. Therefore, it is essential to introduce key concepts; e.g.,
populations, species, communities, etc. It presents a description of how diversity of
species is organized in different taxonomic classes. All relevant phenomena which play
important role in spatial systems are discussed. Allee effect is a phenomenon which
governs the rate of growth of a population at low population densities. At higher
population densities, growth of a population is limited by its carrying capacity. Habitat
fragmentation and Allee effect are two key factors which determine the population
growth and community structure. The chapter identifies challenges for a mathematical
modeler in the present day scenario and indicates how these challenges could be
handled in future. It also describes how the eBook is organized.
Keywords: Populations, Communities, Species, Diversity, Speciation, Allee
effect, Habitat fragmentation, drivers, passengers, Keystone species, competitors,
Population growth, Malthusian model, Verhulst model, Predator–Prey systems,
Homogeneous environment, Non–spatial models, Differential equations,
Heterogeneous environment, Climate change.
