The environment of plants: the biotopes; aquatic environments; soils; reactions of plants to biotopes; the biotic environment. Photosynthesis and plant production: photosynthesis with two photosystems; major factors of the biotope acting on photosynthesis; inputs of fluorimetry; respiration of higher plants and its relationship to photosynthesis; overall productivity on the ecosystem scale. Hydro-mineral equilibrium: plants and water; mineral supply; results - diversity of policies for water management depending on species and habitats. Ecophysiology of development: external factors and hormones in regulation of development; development after germination; senescence and recycling phase; seasonal andmulti-annual variations of development. Plants under stress: definition; what happens during stress?; the effects of stress and its management; stress in practice; stress caused by other living things.