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Classifications of ecosystems
Major components of ecosystems
Life on the earth depends on solar energy
- Flow of energy from the sun through the
biosphere
- The cycling of crucial elements
Human is a component of ecosystems
Terrestrial (land): Rain forest, coniferous
forest, savanna, desert
Aquatic:- Marine : sea. oceans
- Fresh water : lakes, rivers
Transition from land to aquatic (Wet land): Swamp, mangrove
Natural ecosystems:
changes naturally without human interferences
Man-made ecosystems:
require human interferences to manage and to add an energy or matter for maintaining a balance ecosystems (city, village, crop land etc.)
Abiotic (non-living/physical and chemical factors): water, air, nutrient and solar energy
Biotic (living): plants, animals (including humans) , and microorganisms
Law of tolerance:
The existence, abundance, and distribution of a species in a
ecosystems are determined by whether the level of one or more
physical or chemical factors fall within the range tolerated by that species
Different from other organisms, human could enhance the range of their tolerance due to the ability to think, to develop technology and to modify the nature
Flow of energy from the sun through the biosphere
The cycling of crucial elements
Gravity, which keeps atmospheric gases from escaping into space and draws chemicals downward in the matter cycles
Biomass is the mass of all the organisms and organic material in an area.
There is more biomass at the trophic level of producers and fewer at the trophic level of tertiary consumers. (There are more plants on Earth than there are animals.)
Bio=life Mass=weight
Bio + Mass = Weight of living things within an ecosystem.
At least 27% of the earth’s total net primary productivity have been destroyed and altered by human activities
Nutrients are cycled continuously from the nonliving environment (air, water, soil, rock) to living organisms and then back again~biogeochemical cycles
Biogeochemical cycles include:
- 4 main types of nutrient cycle :1. Carbon cycle
2. Nitrogen cycle
3. Phosphorus cycle
4. Sulfur cycle
- Hydrologic (water) cycle
Carbon is the basic building block of molecules necessary for life (carbohydrate, fats, proteins, DNA and RNA)
How are human activities affecting the C cycle? CO2 + other gases Atmosphere green house effects global warming: - select fit organism, affect food production
and wildlife habitats
- raise the average sea level
Nitrogen is an essential nutrient for making proteins, DNA, and RNA
How are human activities affecting the N cycle?
Adding large amount of NO when burning any fuel:
N2 + O2 2NO
NO + O2 NO2
NO2 + H2O HNO3
HNO3 in rain or snow acid deposition (acid rain)
P is the limiting factor for plant growth and producers in many freshwater and lakes
How are human activities affecting the P cycle?
-Reducing the available phosphate in tropical forests by removing trees causes P and other soil nutrients are washed away by heavy rains, and the land become unproductive
-Adding excess phosphate to aquatic ecosystems causes explosive growth of cyanobacteria, algae, and aquatic plants. When these plants die and are decomposed they use up dissolved oxygen and finally disrupt aquatic ecosystems
S is stored underground in rocks and minerals, including SO4
2- salt
S enters the atmosphere from active volcanoes,
S is released by the breakdown of organic matter in swamps, bogs, and tidal flats by decomposers
How are human activities affecting the S cycle?
burning sulfur containing coal and fossil fuels release SO2 into atmosphere
In the atmosphere,
SO2 + O2SO3
SO3 + H2O H2SO4 fall to the earth as acid rain
Water Cycle: collects, purifies and distributes the earth’s fixed supply of water
The main processes in water cycle: evaporation, transpiration, condensation, precipitation, infiltration, percolation, runoff
Water cycle is powered by energy from the sun
How are human activities affecting the water cycle?
- withdrawing large quantities of fresh water in heavily
populated areas lead to depletion of underground water
supplies
- clearing vegetation from land for agriculture, mining, and
building construction lead to increase runoff, reduces
infiltration, increase the risk of flooding
Large-scale changes in the ecosystems (biosphere) threaten us as well as other species
How are human considering the earth ?
Gaia concept (Lovelock): Biosfer adalah suatu kesatuan yang mengatur diri sendiri (self-regulating) dan mampu mempertahankan kondisi Bumi dengan mengendalikan lingkungan kimiawi dan fisis. Hadi, Bumi adalah suatu super-ekosistem dimana banyak proses dan umpan balik saling berinteraksi untuk menjaga kondisi kimiawi dan fisis di Bumi. Dalam hal ini, makhluk hidup memiliki peran penting peran terpenting dalam menjaga keseimbangan (homeostatis).
The earth as a aerospace aircraft (Odum 1989) : Bumi dapat dianalogikan dengan suatu pesawat ruang angkasa yang sangat besar karena merupakan suatu benda/kesatuan yang ‘melayang’ di angkasa luar, dengan sistem pendukung kehidupannya sendiri (dalam bentuk udara, air, makanan, energi). Dengan adanya tekanan penduduk, pencemaran, dan pengelolaan yang buruk, maka sistem pendukung kehidupan ini menjadi terancam:ibarat berkurangnya persediaan oksigen bagi astronot dalam suatu pesawat ruang angkasa.