Plants need space for branches and stems for support of light-gathering, photosynthetic, and respiratory leaves; elaboration of woody tissue provides greater support for big plants. They also need space underground for roots for gas and chemical exchange with the substrate, and for nutrient and water gathering. Competition for space is intense among plants, at leaf and root level. Plant nutrition comes from a from combination of leaf photosynthesis and root gathering. Predator avoidance is by physical (spines, hairs, sticky resins) and/or chemical means (there is an almost infinite number of chemicals in plants that lower their palatability to animals) or even by rarity of the plant, its flowers or fruits. .
Reproduction is by flowers and fruits. As locomotion is lacking, reproduction depends on other features of the environment--wind, water, or animal pollination and seed dispersal. Animals are often important for dispersal of pollen and seeds. Reproductive structures vary widely: inflorescence type, flower sizes, shapes and colors; infructescence type, fruit sizes, shapes and colors; seed sizes and numbers. Most of these are clearly correlated with the mode of pollination/seed dispersal. .
ANIMAL ADAPTATIONS. Animal basic needs include homeostasis, space, refuge, food, predator avoidance, and reproduction. Homeostasis needs lead to occurrence only in restricted range of temperature, humidity, salinity, oxygen level, and other features that affect the animal's internal environment. There is great variation in tolerance to environmental extremes, maximal in endothermal birds and mammals. Land and water are two basic environments, and many animals move between them or secondarily into air for relatively brief periods. Locomotion is significant in animals (lacking in plants for most part) to allow these movements, also movement about home range and long-distance movements that may be for dispersal or may involve seasonal back-and-forth migration.
