Plant ecology is a branch of ecology, which is concerned with the study of the abundance and distribution of plants, the effect of environmental factors and the interactions between plants and other organisms. The plant kingdom ranges in complexity from the single-celled algae to large canopy forming trees. Plant communities are distributed into biomes depending on the dominant plant species present. Some of the important vegetation types are tundra, terrestrial wetlands, temperate grasslands, tropical forests, tropical savannas, etc. The predominant biological interactions occurring in plant communities are competition for resources, mutualism and herbivory. Depending on the level of organization, plant ecology can be divided into plant ecophysiology, community ecology, ecosystem ecology and biosphere ecology, among others. This book studies, analyzes and upholds the pillars of plant ecology and its utmost significance in modern times. It includes some of the vital pieces of work being conducted across the world, on the ecology and diversity of plants. The extensive content herein provides the readers with a thorough understanding of the subject.