Choi 1 Wendy Choi Mr. Cook IB Biology (Period 3) 19 Sept 2008 Biology Syllabus 5.2.2 – 5.2.6, G.3.1 – G.5.6
5.2.2 Analyze the changes in concentration of atmospheric carbon dioxide using historical records. Gregg Marland & Tom Boden Environmental Sciences Division Oak Ridge National Laboratory
Obviously from these graphs, the level of atmospheric carbon dioxide concentration has increased significantly throughout the years. An exponential growth in CO2 concentration is especially visible during the 18th and 19th century, when the major countries around the world underwent industrial revolutions. Tracing back further:
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It is obvious that other than human causes, natural causes such as the ice age cycles also cause a significant change in atmospheric concentration of carbon dioxide. Overall, however, the dramatic rise in the level of concentration of carbon dioxide is caused by human interference with nature through chemical pollutants and technological reasons.
5.2.3 Explain the relationship between rises in concentrations for atmospheric carbon dioxide, methane and oxides of nitrogen and the enhanced greenhouse effect.
According to a recent research “U.S. Anthropogenic Greenhouse Gas Emissions by Gas, 2006 (Million Metric Tons of Carbon Dioxide Equivalent),” it is obvious that the rise in concentration of CO2, Methane, and nitrogen oxides contributes to the greenhouse effect, or the warming of Earth’s surface when earth’s atmosphere traps heat from the sun. Due to the fact that infrared radiation and heat are long wave radiations, they do not pass through greenhouse gases such as carbon dioxide, methane and oxides of nitrogen.
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5.2.4 Outline the precautionary principle.
"When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically. In this context the proponent of an activity, rather than the public, should bear the burden of proof. The process of applying the precautionary principle must be open, informed and democratic and must include potentially affected parties. It must also involve an examination of the full range of alternatives, including no action." - Wingspread Statement on the Precautionary Principle, Jan. 1998
5.2.5 Evaluate the precautionary principle as a justification for strong action in response to threats posed by the enhanced greenhouse effect. According to the precautionary principle, it will be too late to stop environmental threats if we wait for the effect to prevail before we take action to stop potential threats. Thus, the proponent of environmental harm should prove their actions as safe for the environment instead of the public trying to find evidence to prove the harmful effects that’s already been done to the environment. Thus, the precautionary principle justifies strong actions in response to threats. 5.2.6 Outline the consequences of a global temperature rise on arctic ecosystems.
Choi 4 Global warming greatly impacts our ecosystems. In fact, even a .6°C change in temperatyre is globally observable; at a 1°C change, world oceans and Arctic ecosystems are damaged; at 1.5°C Greenland and Ice Sheet melting begins; whereas a 2°C change in temperature signifies a decreased agricultural yield, water stress, famine, sea level rises, the spread of malaria, collapse of Arctic systems and extinctions. Thus, a stable global temperature is the key to maintaining Arctic systems. (Schnellnhuber 93)
G.3.1 Calculate the Simpson diversity index for two local communities. Simpson's Diversity Index (D) is a measure of diversity to quantify the biodiversity of a habitat. It takes into account the number of species present, as well as the abundance of each species, with focus in two main areas: richness and evenness. To estimate an infinite population, one uses equation #1; to estimate a finite population, one uses equation #2!
1.
D=
(n / N)2
2.
n = the total number of organisms of a particular species N = the total number of organisms of all species Thus, 0 represents infinite diversity and 1, no diversity. That is, the bigger the value of D, the lower the diversity. This is neither intuitive nor logical, so to get over this problem, D is often subtracted from 1 to give: Simpson's Index of Diversity 1 - D The value of this index also ranges between 0 and almost 1, but now, the greater the value, the greater the sample diversity. This makes more sense. In this case, the index represents the probability that two individuals randomly selected from a sample will belong to different species.
Simpson's Reciprocal Index 1 / D The value of this index starts with 1 as the lowest possible figure. This figure would represent a community containing only one species. The higher the value, the greater the diversity. The maximum value is the number of species (or other category being used) in the sample. For example if there are five species in the sample, then the maximum value is 5.
Thus, Simpson’s index for a single quadrat sample of ground vegetation at woodland would be:
Choi 5 Species Woodrush Holly (seedlings) Bramble Yorkshire Fog Sedge Total (N)
Number (n) 2 8 1 1 3 15
n(n-1)
n(n-1) 2 56 0 0 6 . .
64
So D= 64/ (15)(14), or 64/210 = 0.3 Simpson’s index of diversity = 1-.3 = .7 Simpson’s Reciprocal index = 1/D or 1/.3 = 3.3 Cited from online document "Simpson's Diversity Index"
A second example is the diversity of wildflowers in the Mongolian grasslands: Numbers of individuals Flower Species Daisy Dandelion Buttercup Total
Species Daisy Dandelion Buttercup Total (N) Sum of n(n-1)
Sample 1 300 335 365 1000
Number (n) (300+20)/2 = 160 (335+49)/2 = 384 (365+931)/2 = 648 1192
So D = 591768/ 1192(1191) = approx .4168 Simpson’s index of diversity = 1-.4168 = approx .5831
Sample 2 20 49 931 1000
n(n-1) 25440 147072 419256 591768
Choi 6 Simpson’s Reciprocal index = 1/.4168 = approx 2.399 Cited from article ""Biodiversity"
G.3.2 Analyze the biodiversity of two local communities using the Simpson diversity Index.
Woodland Vegetation:
Woodland D= 0.3 Grassland D= .4168
the bigger the value of D, the lower the diversity; therefore, grassland has a lower diversity than woodland
Simpson’s index of diversity = .7 For grassland = .5831
P (random selected individual would be of diff species); therefore, woodland > diverse than grassland
Simpson’s Reciprocal index = 3.3 For grassland = 2.399
higher = greater diversity; therefore woodland, again, is more diverse than grassland
G.3.3 Discuss the reasons for the conservation of biodiversity using rainforests as an example. Conservation of biodiversity is important because it is vital to the existence of all ecosystems. For example, in a rainforest (and in all other ecosystems), primary producers are the food sources of secondary consumers, who may be eaten by tertiary consumers. Thus, the plants that use chlorophyll and sunlight to create food for their own growth and animals through the process of photosynthesis such as mushrooms, moss, grasses, and wild flowers are consumed by mostly small animals like voles, chipmunks, squirrels, seed eating birds, salmon, slugs, snails, and deers etc.; whereas decaying materials such as dead leaves, logs, needles, and twigs serves as the food source of the detritivores. These primary consumers are then eaten by secondary consumers, for example: frogs eat mosquitoes, some birds eat insects, weasels eats rodents and smaller animals, and raccoons generally eat fruit, berries, grain, eggs, poultry, vegetables, nuts, and insects…etc. Thus, any part of those missing is devastating to the environment because they are all interdependent on each other in the cycles of their ecological food web.
G.3.4 List three examples of introduction of alien species that have had significant impact on ecosystems. In the Hawaiian Islands, the parasitic large, dark green leaves with maroon undersides to trees from mid-elevation forests of Central and South America was introduced in the 1970s’ as an ornamental. Soon, it spreads aggressively with its high capacity and speedy mass-seedling, which outcompeted many native species there such as some pine and pineapple trees. (Gagne, Lloyd, Medeiros, and Anderson 7)
Choi 7 “The establishment of the alien tree Myrica faya in the near-native ecosystems of the Hawaiian Islands seriously threatens the integrity and survival of these ecosystems and the endemic plant populations and communities within them,” and the open-canopied forests of the seasonal submontane zone of Hawaii Volcanoes National Park (HAVO) on the flank of Kilauea, have been aggressively incaded by Myrica faya over the past 20 years (Lipp 9). Moreover, seasonally dry zone of shrubs and grasslands dominated by the alien grasses Melinus Minutiflora and Schizachrium condesnatum, which are also in favor of M. faya growth with large seed inputs. In these cases, each alien species seem to have assisted the other kind in invading an ecosystem (Lipp 10).
G.3.5 Discuss the impacts of alien species on ecosystems. Invasive species modify all the major ecosystem processes in a way that would suit themselves the best. Alteration in litter dynamics is the first and foremost impact observed in the ecosystem, which an invader invades. Gradually other ecosystem processes depending on litter dynamics viz. soil biota, nutrient dynamics and biogeochemical cycles are also modified. Later, geomorphology and hydrology of the area are also changed as invasion proceeds. During the course of establishment these invasive species also interfere with native species recruitment either by allelopathic suppression or by competing with seedlings for resources. The invasive species are also known to alter fire regimes. G.3.6 Outline one example of biological control of invasive species. One example of biological control is the ladybird Delphastus, which feeds on up to 150 whitefly eggs or larvae of whitefly a day. Adult whiteflies give birth to their youngs on grasshouse plants where they feed upon sucking the sap. Consequently, the young whiteflies excrete a sticky “honeydew” upon which sooty molds develop and reduce the amount of light available to the leaves of the tree or bush that they inhabit. Thus, the ladybird Delphastus and the tiny parasitic wasp Encarsia are used to control the whitefly populations.
G.3.7 Define biomagnifications. In ecology, biomagnification, or bioaccumulation, is the progressive concentration of pesticides with increasing trophic level.
G.3.8 Explain the cause and consequences of biomagnifications, using a named example. Biomagnification– the progressive concentration of pesticides with increasing trophic level– is caused by the a pesticide’s persistence (how long it remains in an environment) and its specificity (how selective it targets a pest). Due to a broad specificity and a pesticide’s resistance to biological breakdown, pesticides cannot be metabolized or excreted and are
Choi 8 accumulated by storage in fatty tissues. Thus, the higher order consumers may ingest harmful or lethal quantities of a chemical because they eat a large number of low order consumers. One named example would be predatory birds consuming mammals that have eaten plants with pesticide or other preys that have eaten contaminated plants.
G.3.9 Outline the effects of ultraviolet radiation on living tissues and biological productivity. Ultraviolet radiation can cause health problems such as severe sunburns, increased rates of skin cancers, and more cataracts of the eye (in both human and other animals); an increase in UV-B radiation is likely to cause immune system suppression in animals, lower crop yields, a decline in productivity of forests and surface dwelling plankton, more smog, and changes the in global climate. (Source of information: Biozone 2008)
G.3.10 Outline the effect of chlorofluorocarbons (CFCs) on the ozone layer. CFCs are chemically constructed as CCl3F, or one carbon molecule, 3 chlorine molecules, and one fluorine molecule. When UV lights strikes a CFC molecule, a chemical reaction occurs and a chlorine atom is released. This chlorine then reacts with the ozone layer— which is composed of ozones (O3)— taking an oxygen away and forming a chlorine oxide molecule (Cl-O), which then reacts with ozone again, forming 2 oxygen(O2) molecules.
G.3.11 State that ozone in the atmosphere absorbs UV radiation. “Stratospheric Oxygen and Ozone molecules absorb 97-99% of the sun's high freguency Ultraviolet light, light with wavelengths between 150 and 300nm. Ultraviolet-B(UV-B) is a section of the UV spectrum, with wavelengths between 270 and 320nm.” (“NASA: Ultraviolet Radiation”)
G.4.1 Explain the use of biotic indices & indicator species in monitoring environmental change. Biotic index is a scale from 1 to 10 in for showing the quality of an environment by indicating the types of organisms present in it, which corresponds to the six water quality classes. It is often used to assess the quality of water in rivers, such as providing a simple measure of stream pollution and its effects on the biology of the stream. They are indicator species when used as a guide to the level of a particular abiotic factor, defining a trait or characteristic of the environment. For example, the presence of certain invertebrate groups in freshwater can be awarded a score that indicates the quality of the water. G.4.2 Outline the factors that contributed to the extinction of one named animal species. The passenger pigeon (Ectopistes migratorius) also known as the wild pigeon was a species of pigeon that was once the most common bird in North America and has gone into extinction for many reasons. Some of the most commonly known reasons are commercial exploitation of
Choi 9 pigeon meat on a massive scale through excessive trap shooting and even the use of pigeon meat as an agricultural fertilizer. Other reasons include its loss of habitat from deforestation and slaughtering.
G.4.3 Outline the biogeographical features of nature reserves that promote the conservation of diversity. Nature reserves may be designated by government institutions in some countries or by private landowners. The different types of nature reserves, e.g. wildlife, scenic and scientific reserves, and National Parks, all have varying levels of protection depending upon country and local laws. Some biogeographical features of nature reserves include: 1) Large reserve > small reserve 2) Single, undivided reserves > number of small reserves (but research has shown that many islands are more diverse than single areas, which may be explained by greater isolation between areas which allows for trophic equivalency) 3) If divided, reserves should be spaced equally from another, not linearly 4) If reserves are linear, connect with corridors (migration between reserves is vital to maintain the genetic health of populations, but some argue that little data exists to show that corridors are used by target species) 5) If reserve = small/ isolated, it should be circular, not linear G.4.4 Discuss the role of active management techniques in conservation. Active management techniques in conservations include captive breeding and relocation, or “captured and bred animals under protected conditions”; habitat protection and restoration, or “whole ecosystem conservation…through pest and weed control programs, revegetataion, and reintroduction of threatened species”; zoos and gene banks, or “botanical gardens raise endangered plant species…preserving the genetic diversity of species”; and cites, or “international agreement between governments which aims to ensure that international trade in species of wild animals and plants does not threaten their survival,” which does not guarantee safety from illegal trade. (Allan 383)
G.4.5 Discuss the advantage of in situ conservation of endangered species (terrestrial and aquatic reserves). In-situ conservation measures are usually "on-site conservations," the process of protection within a species’ natural habitat through either protecting or cleaning up the habitat itself, or by defending the species from unwanted predators. These include habitat protection and restoration, or “whole ecosystem conservation…through pest and weed control programs, revegetataion, and
Choi 10 reintroduction of threatened species,” which are methods widely used in terrestrial and aquatic reserves (383). G.4.6 Outline the use of ex-situ conservation measures, including captive breeding of animals, botanic gardens and seed banks. Ex-situ conservation measures are "off-site conservations" to protect an endangered species of plant or animal through the removal of part of the population from a threatened habitat and relocating it, which may be a wild area or within the care of humans. As mentioned before in G.4.4, these techniques include captive breeding and relocation, or “captured and bred animals under protected conditions”; zoos and gene banks, or “botanical gardens raise endangered plant species…preserving the genetic diversity of species” (383).
G.5.4 Describe the methods used to estimate the size of commercial fish stocks. Stocks of commercially fished species must be managed carefully to ensure that the catch (take) does not undermine the long term sustainability of the fishery. This requires close attention to stock indicators, such as catch per unit of fishing effort, stock recruitment rates, population age structure, and spawning biomass. (391)
G.5.5 Outline the concept of maximum sustainable yield in the conservation of fish stocks. The concept of MSY is based on a largest yield that can be taken from a species' stock over an indefinite period of time. Assuming the population is of logistic growth, the MSY should be exactly half the carrying capacity of a species, when population growth is highest.
G.5.6 Discuss the international measures that would promote the conservation of fish. With over exploitation of wild fishes and overfishing, the Total Allowable Catch (TAC, catch that can be legally taken from stock) has been set at approximately half that set for the year 2000. Further regulations, such as increasing net mesh size and reducing the volume of fish discarded, are planned, and will further restrict the effort of fishing fleets until the stock recovers, if possible. The International Council for the Exploration of the Sea (ICES) has recommended a recovery plan that will ensure recovery of spawning fish stock to a level of over 150 000 tons. Reductions in TAC alone are insufficient to stop the declines (391).
Choi 11 Citations
Allan, Richard. Biozone Biology 1 2008 Student Workbook. 7th ed. Hamilton, New Zealand: BIOZONE International Ltd., 2008. "Biodiversity." Rochester Area Colleges Center for Excellence in Math and Science 2007. 2007. Rochester Area Colleges Center for Excellence in Math and Science . 24 Sep 2008 . "Carbon Dioxide Emissions Booming, Shifting East, Researchers Report." Science Daily. 24 Sep 2008. Oak Ridge National Laboratory. 27 Sep 2008 . "Climate Chage Primer." The Climate Change Resource Center. 14 Jul 2008. US Forest Service - Climate Change Resource Center. 22 Sep 2008 . Joachim Schnellnhuber, Hans, Wolfgang P. Cramer, Great Britain Dept. for Environment, Food & Rural Affairs, Nebojsa Nakicenovic, Tom Wigley. Avoiding Dangerous Climate Change. New York: Cambridge University Press, 2006. Gagne, Betsy, Lloyd L.Loope, Arthur C. Medeiros, and Stephen J. Anderson. “Miconia calvescens: A Threat to Native Forests of the Hawaiian Islands.” Impact of Alien Species on Island Ecosystems-Abstracts. 22 Sep 2008 Lipp, Cindy. “Ecophysiological Factors Influencing Myricafaya Invasion ofHawaii Volcanoes National Park” Impact of Alien Species on Island Ecosystems-Abstracts. 22 Sep 2008 "Precautionary Principle." Science and Environmental Health Network. 24 Sep 2008. Science and Environmental Health Network. 24 Sep 2008 . "Simpson's Diversity Index." Offwell Woodland & Wildlife Trust. 2004. Offwell Woodland & Wildlife Trust. 24 Sep 2008 .
