Ecology Notes (Med 2) PDF

Chapter 4 I É - There are three models for explaining environmental pyramids Pyramid of energy....

Chapter 4 I É - There are three models for explaining environmental pyramids Pyramid of energy. Pyramid of biomass. Pyramid of numbers Expresses the flow of energy It expresses the amount of concerned with the total in food webs (it cannot be inverted. living matter (Can be number of each trophic (in nature) Perfect for representing. inverted in nature. gradient or level (which the ecological pyramids. can be inverted in nature) rise If y g High ‫ إلى‬low ‫من‬ ( losing energy )  Primary Productivity ➡ producer and plant ( The issue of productivity is mainly related to products that use photosynthesis to provide and store energy ) Secondary productivity ➡ consumer and decompres Net primary Productivity ➡ NPP = GPP -R Community energy budget ➡ NEP = GPP - ( Rp + Ra + Rd ) 53 Net Primary Production ➡ NEP = GPP- Rp The most productive ecosystems ➡ systems with high temperatures and plenty of water the most productive of the ecosystems ➡ The Tropical Rain Forests The least productive ecosystems ➡ those limited by heat energy and water like the deserts and the polar tundra. Productivity is measured by either carbon consumption and oxygen production 1- Oxygen production ➡ This method is often used to measure the productivity of aquatic ecosystems 2- CO2 consumption ➡ This method is often used to measure the productivity of terrestrial ecosystems Chlorophyll content ➡ It is the newest and most important method of calculating productivity in ecological societies Chapter 5 Biogeochemical cycles of particular interest in ecology are: 1- Nitrogen cycle 2- Oxygen cycle 3- Carbon cycle 4- Phosphorus cycle 5- - Sulfur cycle 6- Water cycle Some of them are fast and are represented by the cycle of elements, most of which are in the gaseous state ➡ carbon-nitrogen- water cycle). are slow and are represented by the cycle of elements, the majority of which are in the sedimentary state➡ (the phosphorous-sulfur cycle). Some of the cycles of quick-complete-rotation elements (gas) ➡ 1- Water cycle. 2- carbon cycle 3- nitrogen cycles. 4- oxygen cycle Biogeochemical cycles ⬇ Step 1: Evaporation Step 2: Condensation Step 3: Precipitation  carbon cycle ➡ Carbon is the main component of biological compounds as well as a major component of many minerals such as limestone. the amount of carbon in this system does not change oxygen cycle ➡ is oxygen in the air at a rate of 21% + dissolved in water + upper layers of the atmosphere in the form of ozone. nitrogen cycle ➡ ( Nitrogen xation) The conversion of nitrogen gas (N2) into nitrates and nitrites through atmospheric, industrial Nitrogen xation 2 Types ⬇ 1- Bio xation ➡ By nitrogen- xing bacteria and algae 2- Physiacal xation ➡ lightning The nitrogen cycle ➡ begins with green plants. ( All cycle start with plant ) Nitri cation ➡ The conversion of ammonium to nitrate + ( oxidation). + ( Aerobic) Denitri cation➡ is the reduction of nitrates back into nitrogen gas (N2). + ( reduction). + (Anaerobic) 1  Chapter 6 Importance of Phosphorus 1- hcluded in the composition of living matter are protoplasm, cell membranes, DNA-RNA genetic material, and energy carriers such as ATP. 2- An essential element in all living organisms and organic synthesis 3- The main function of phosphorus ➡ the formation of bones and teeth Phosphorus ➡ It is a slow-moving sedimentary cycle +. large part of it is stored in the rocks The importance of sulfur 1- It is used to activate some enzymes 2- An essential component of many proteins 3- In reactions to remove toxic substances in the body The presence of sulfur in nature -S - H2S. - SO4^-2 Sulfur sources ➡ Volcanoes. + Atmospheric erosion of some sulfur-containing rocks