Ecology Notes PDF

# The Biosphere and Distribution of Life on Earth - **Biosphere:** thin outer layer of the earth. - **Lithosphere:** rocky part of the earth's surface. - **Hydrosphere:** water part on the earth's surface. - **Atmosphere:** gaseous component of the earth's surface. ## Biome - A biome is a specifi...

# The Biosphere and Distribution of Life on Earth - **Biosphere:** thin outer layer of the earth. - **Lithosphere:** rocky part of the earth's surface. - **Hydrosphere:** water part on the earth's surface. - **Atmosphere:** gaseous component of the earth's surface. ## Biome - A biome is a specific geographic area notable for the species living there. - A biome can be made up of many ecosystems. ## Major Terrestrial Biomes - Deciduous forests - Coniferous forest - Tropical rainforest - Grassland - Tundra - Desert ## Major Aquatic Biome - Desert - Fresh waters - Marine waters - Estuary and Mangroves ## How Animals are Distributed - Animals have become distributed in two ways: - **Dispersal:** population moves from one place to another. - **Vicariance:** separation of populations due to environmental and climate changes. # Levels of Ecological Organization - **Ecosystem** - **Community** - Population - Organism # Ecology - The study of the relationship between organisms (plant and animals) in relation with their environment. - **Environment** is a term often used to refer to the immediate surroundings of an organism. # Ecosystem Component - The abiotic component of an ecosystem is characterized by its physical parameters and it is established the basic nature of the ecosystem. ## Abiotic Components - Inorganic and organic compounds (i.e, water, nitrogen, and carbon cycles, carbohydrates, lipids, and proteins) - Temperature - Light - Moisture - Altitude ## Biogeochemical Cycles - Matter moves between ecosystems, biotic & abiotic environments, and organisms. - Unlike energy, biogeochemical cycling involves biological, geologic and chemical interactions. - **Five major cycles:** - Carbon - Nitrogen - Phosphorus - Sulfur - Water (hydrologic) ## The Water Cycle - Collects, purifies and distributes water supply. - The cycle includes: - Volcanic steam - Ice and snow - Infiltration - Precipitation - Snowmelt runoff - Streamflow - Seepage - Spring - Groundwater discharge - Water in the atmosphere - Sublimation - Desublimation - Evapotranspiration - Fog drip - Surface runoff - Dew - Condensation - Evaporation - Flora and fauna - Plant uptake - Freshwater - Groundwater storage - Vents and volcanoes - Oceans ## The Carbon Cycle: - Carbon is the basic constituents of organic compounds (carbohydrates, fats, proteins, and nucleic acids) and required by living organism for respiration, assimilation and photosynthesis. - The cycle includes: - Carbon dioxide in the atmosphere - Weathering of terrestrial rocks - Respiration - Fossil carbon - Soil carbon - Human emissions - Terrestrial photosynthesis - Leaching/Runoff - Oceans - Ocean sediments - Air sea gas exchange - Respiration - Marine photosynthesis - Microbial respiration and decomposition - Uplifting. ## The Nitrogen Cycle: - Nitrogen accounts for almost 78% of the atmosphere and is an essential constituent of living materials (particularly proteins and nucleic acids). - The cycle includes: - Nitrous oxide from fossil fuels falls as nitric acid in rainwater. - Runoff from nitrates in farming enters water. - Lighting creates soil nitrates. - The air is 78% nitrogen gas. - Nitrogen compounds eventually break down into gas and return to the air. - Animals eat plants. - Plants obtain nitrate ions from soil and water bacteria. - Bacteria in soil and water "fix" nitrogen from the air. - Decomposer bacteria break down animal and plant matter into nitrogen compounds. # Biotic Components - The living part of our ecosystem includes the cabbage, pepper, roly polys, spider, crickets, worms and bacteria. # Producers - Producers are autotrophs such as algae and green plants, which use energy from the sun for photosynthesis. # Consumers - Also known as heterotrophs, consumers get their energy directly or indirectly on producers. - Major classes of consumers are: - Herbivores - Carnivores - Omnivores - Detritivores ## Herbivores: - Herbivores are primarily consumers or plant eaters. - Examples include: - Panda - Rabbit - Deer - Grasshopper ## Carnivores: - Carnivores the secondary consumers, which feed directly on animals. - Examples include: - Bull Shark - Nile Crocodile - Gila Monster - Piranha ## Omnivores: - Omnivores are the tertiary level of consumers that feeds on herbivores and carnivores. - Examples include: - Pig - Raccoon - Human - Chimpanzee - Dog - Rat - Civet - Badger - Brown Bear - Monkey - Warthog - Coati - Skunk - Squirrel ## Detritivores: - Detritivores eat dead plants and animals (also called decomposers). - Examples include: - Worms - Beetles - Bacteria - Fungi # Energy - Energy flows into the ecosystem as sunlight and almost all life depends on the conversion of energy into organic compounds by the fixation of carbon dioxide in green plants. # Production, Food Chain, Food Web, and Trophic Level: - **Production** is the energy accumulated by the plants in photosynthesis. It is a prerequisite of energy input into the ecosystem. - **Primary productivity** is the rate of energy storage per unit of time by plants. - **Gross productivity** (total rate of energy storage) could not be entirely available for growth because plants also use energy for reproduction. - **Biomass** (standing crop) is the accumulation of biomass, expressed as the weight of dry organic matter per unit area. It is possible to have a low biomass production as it is rapidly grazed by consumers. ## Food Chain: - A food chain describes the way the energy flows through the ecosystem. - Plants are eaten by consumers, which are then consumed by another consumers and so on. ## Food Web: - Food webs show the interconnected relationships among various food chains in the ecosystem. ## Trophic Level: - A trophic level is a step in the food chain. - It means the organism's feeding level of food in the food chain. - Higher trophic levels receive less energy due to energy transfer. # Community - Community is the most tangible concept in the ecosystem. - It comprises the biotic portion of the ecosystem with a population of interbreeding organisms belonging to the same species. - Example: oyster community. # Ecological Dominance - Community is typically dominated by a single group of species that greatly influence the nature of the environment. - Dominant organism or species can occupy the space that might otherwise be occupied by other species. # Ecological Niche - Niche is the animal's place in the biotic environment. It includes the interaction, relationship and food needs. -Any sets of condition under which animal population exist. # Population - Population is a group of organisms belonging to the same species that share a particular place or space. - It bears a number of attributes unique to the group. # Species Interaction: - 1.**Competition:** When two or more species in the same ecosystem use the same niche, which can lead to diversification. - 2.**Predator-prey relationship:** In which individuals of a predator population kill and eat individual's of a prey population. - 3.**Parasite-host relationship:** Both parasites and predators feed at the expense of their host-prey. Parasites, which are usually smaller than their host, live for a good stage of their life cycle. - 4.**Commensalism:** Is sometimes symbiotic, in which one type of organism (commensal) enjoys some benefit from the relationship but does not harm the host. - 5.**Mutualism:** An interaction in which both species benefit. - 6.**Protocooperation:** Is a mutually beneficial interaction not physiologically important to the survival of the partners . # Population Growth - Unrestricted growth of organism can happen only in the environment when there is an abundance of resources and no competition. - When food and space. are not limiting and the growth is exponential, the limit to the environment is approached. - This limit, the maximum density the environment can support, is called the carrying capacity of the environment. - When population reached the carrying capacity of the environment, they may remain or fluctuate above and below the limit. ## Density Dependent: - Density-dependent population control factors include: - Overcrowding - Food and space limitations - Disease - Predation and stress. ## Density Independent: - Density-Independent factors include: - Extreme weather - Abrupt environmental change - Hazard of varying severity to the population. # Land - Land has managed to support life of part of the earth's inhabitants. - Plants receive nutrients and water from soil. - Animals feed on products of the land. - Humans are dependent on land for food and natural resources. **Our role is to maintain the balance of nature.** ## Types of Land ### A. Agricultural Land: - 10.3M hectares of land - agricultural production, 45% lowlands, 33% uplands. - Rate of land use conversion- 2300 hectares per year. - Soil degradation. - 5.2M hectare - 17% of the country is severely eroded, 8.5M hectares (28.3%) moderately eroded and 8.8M hectares (29.4) slightly eroded. - Mindanao has the biggest share of erosion at 2.4M hectares. ### B. Forest Land: - 15.8 million hectares are forest land: Dipterocarp, Mossy, Sub marginal, Pine, Mangrove. - Forest depletion is estimated to be 200,000 hectares per year. - 27.5 M hectares of virgin forest (16th century). - Causes of forest destruction: Forest fires, illegal logging, land use of conversion, kaingin, human settlements. - Forest destruction contributed to: Massive erosion and siltation, reduced groundwater, saltwater intrusion. ### C. Urban Land: - Filipino population is still predominantly rural based but urban population is increasing from 37%, 44%, to 48.5 % in 1990. - Population density of Manila is 51,044 person/sq.km. - National average is 288 person/sq.km. - Density resulted in environmental problems such as: Congestion, dilapidates, housing structure, poor sanitation.