ECOLOGY Prof. Dr. Ir. Nastiti Siswi Indrasti

Introduction  Ecology (Greek, oikos, meaning house; logy, the study of)  the study of the relationship between organisms and their environment  An ecosystem is a group of plants or animal, together with part of the physical environmental with they interact. An ecosystem is defined to be nearly self-contained, so that the matter which flows into and out of it is small compared to the quantities that are internally recycled in a continuous exchange of the essentials of life  Biota are all the living elements of an ecosystem or a given area

Estimates of Primary Production  An autotroph is an organism that obtains its cell carbon from an inorganic source (CO 2, HCO 3 ) and its energy from the sun (actually, a photoautotroph as distinct from a chemoautotroph, which gets its energy from the oxidation of inorganic chemical compounds)  A heterotroph is an organism that obtains both its cell carbon and its energy from organic matter  A chemotroph is an organism that obtain its energy from the oxidation of simple inorganic compounds, such as FeS and H2S, and its cell carbon from inorganic and/or organis matter. Chemotrops are relatively insignificant in the energy relations of an ecosystems, but play a significant role in the movement of mineral nutrient in the ecosystem

Estimates of Primary Production  The food chain is an idealized pattern of flow of energy in a natural ecosystem. In the classical food chain, plants are eaten only by primary consumers, primary consumers are eaten only by secondary consumers, and so on.  The food web is the actual pattern of food consumption in a natural ecosystem. A given organism may obtain nourishment from many different trophic levels, thus giving rise to a complex, interwoven series of energy transfer  Productivity is the rate of fixation of energy into tissue. Primary productivity is energy fixation by plants; secondary productivity is at higher trophic levels

Food Chain

Food Web

Estimates of Primary Production  Trophic levels are levels of nourishment. A plant that obtains its energy directly from the sun occupies the first trophic level (autotroph). An organism that consumes the tissue of an autrotroph occupies the second trophic level (herbivore), and an organism which eats the organism that had eaten autrotrophs occupies the third trophic level (carnivore)  Tranpiration is the controlled evaporation of water vapor from the surface of leaf tissues

Transfer of Energy

Transfer Energy

Carbon Cycle

Nitrogen Cycle

Phosphorus Cycle

Elements of Limnology  Limnology is the study of the phisycal, chemical and biological characteristic of river and lakes (i.e. fresh water)  A benthic organism is a plant or animal that lives at or near the bottom of a lake, river, stream or ocean  The epilimnion is the upper layer of water in a lake  The euphotic zone is that surface volume of water in the ocean or a deep lake that receives sufficient light to support photosynthesis  The hypolimnion is the lower layer of water in a lake or pond, which will remain at a constant temperature during the summer months

Elements of Limnology  Plankton are any small free-floating organism living in a body of water; phytoplankton refers to the plant species (algae), and zooplankton to the animal species (crustacean, rotifers, protozoa) feeding on other forms of plankton  The metalimnion is the middle layer of water in a lake, where the thermocline occurs (temperature and oxygen content fall off rapidly with depth)

Light in Lake PhytoplanktonZooplankton

Communities of Freshwater lakes

Eutrophication  Eutropication is the natural process of nutrient enrichment that occurs, over time, in a body of lake. The resulting biological growth, mainly algae, in the epilimnion dies and settles to the hypolimnion, where it decays and depletes the oxygen from the water

Eutrophication

Control of eutrophication  Reduced the inflow of nutrients  Quantitative survey: nitrogen, phosphorus sources, limn logical studies  Alternative disposal on land, diversion around the lake  Nutrients from the waste water prior to discharge to surface waters

Political Ecology  Scientific study is not enough; social, economic and political issues must be considered.  Political ecology is the study of the relationship between society and nature  Political ecology holds that radical changes in human social habits and practices are required in order to counter environmental degradation and achieve sustainable development  Political ecology Implies an interest in cause-effect relationship, study of the different interest groups involved in using the environment, of their economy, habits and livelihoods