FBS 31 Plant Physiology Lecture 1 PDF

FBS 31 PLANT PHYSIOLOGY Marilyn S. Combalicer, Ph.D. Forest Biological Sciences, CFNR, UPLB  INTRODUCTION Plant Physiology – study of processes that take place within a plant. Closely related fields: plant morphology (structure of plant...

FBS 31 PLANT PHYSIOLOGY Marilyn S. Combalicer, Ph.D. Forest Biological Sciences, CFNR, UPLB  INTRODUCTION Plant Physiology – study of processes that take place within a plant. Closely related fields: plant morphology (structure of plants) Plant ecology (interactions with the environment) Phytochemistry (biochemistry of plants) Cell biology, genetics, biophysics & molecular https://commons.wikimedia.org/wiki/File:Plant_physiology.png biology Plant physiologists – interested in the nutrition of plants, influence of the environment upon plant processes, the products of plant activities, and the https://en.wikipedia.org/wiki/Physiology sequence of events that results in growth and development of plants. ❑ Plants respond to a variety of environmental conditions ▪ Light (photoperiod) ▪ Temperature ▪ Gravity ▪ Nutrient and water availability ▪ Disease ❑ Activities of many plant species: ▪ Seed germination ▪ Growth (stems, roots, leaves, buds, etc.) ▪ Flowering ▪ Opening and closing of stomata ▪ Tropism, etc. ❑What plants do? ▪ Find water and nutrients and transport them to where they are needed within the plant ▪ Carry out photosynthesis and respiration ▪ Grow and reproduce ▪ Protect themselves from herbivores and pathogens, etc. https://en.wikipedia.org/wiki/Photosynthesis The Role of Plant Physiology in Forest -How the plants grow and how the benefits accruing from their presence can be maximized. -Common practices followed in forestry like leaf and branch pruning, timber stand improvement techniques, mulching, weeding, etc. have physiological basis.  The Role of Plant Physiology in Forest 2. Relation of Physiological Processes and Forest Growth Forest – defined as a community of plants dominated by trees. Forest growth – a result of physiological processes of the plant. Growth, Development and Reproduction Growth - a process of irreversible increase by cell division and enlargement, including synthesis of new cellular material and organization of sub cellular organelles. It is the process involving conversion of reserve materials into structural materials. Development - process of qualitative change in plants over time. It is phasic in nature (vegetative and reproductive) which is controlled by various environmental and genetic factors. Reproduction – is the production of new individual plants or offspring by sexual or asexual means. Processes of Plant Growth Plants carry out a number of processes that are essential to their survival: ❑Photosynthesis - the food and manufacturing process in green plants that combines carbon dioxide and water in the presence of light to make sugar and oxygen. ❑Respiration - the process through which plant leaves, stems and roots consume oxygen and give off carbon dioxide. ❑ Absorption - the process by which plant roots take in water and air. ❑ Transpiration - the process by which plants lose water from leaves and stems through evaporation. ❑ Translocation - the process by which food and nutrients are moved within a plant from one plant part to another. ❑ Reproduction - the plant process that increases plant numbers.