Do you want to create an amazing science fair project for your next exhibition? You are in the right place. Read the below given article to get a complete idea on biodiversity:- 1. Meaning of Biodiversity 2. Magnitude of Biodiversity 3. Gradients 4. Uses 5. Levels 6. Major Threats 7. Hot Spots.
Contents:
- Science Fair Project on the Meaning of Biodiversity
- Science Fair Project on the Magnitude of Biodiversity
- Science Fair Project on the Gradients of Biodiversity
- Science Fair Project on the Uses of Biodiversity
- Science Fair Project on the Levels of Biodiversity
- Science Fair Project on the Major Threats to Biodiversity
- Science Fair Project on the Hot Spots of Biodiversity
Science Fair Project # 1. Meaning of Biodiversity:
‘Biological diversity’ encompasses all species of plants, animals, and microorganisms and the ecosystems and ecological processes of which they are parts. It is an umbrella term for the degree of nature’s variety including both the number and frequency of ecosystems, species, or genes in a given assemblage. Thus, the term ‘biodiversity’ refers to the totality of ‘genes, species and ecosystems’ of a region.
It is usually considered at three different levels:
(i) Genetic diversity,
(ii) Species diversity and
(iii) Ecosystem diversity.
Genetic diversity is the sum total of genetic information, contained in the genes of individuals of plants, animals and microorganisms that inhabit the earth.
Species diversity refers to the variety of living organisms on earth and has been variously estimated to be between 5 and 50 million or more, though only about 1.4 million have actually been described.
Ecosystem diversity relates to the variety of habitats, biotic communities, and ecological processes in the biosphere, as well as the tremendous diversity within ecosystems in terms of habitat differences and the variety of ecological processes.
Biodiversity is defined as “the variability among living organisms from all sources, including terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are a part; this includes diversity within species, between species and of ecosystems.”
Conservation and sustainable use of biodiversity is fundamental to ecologically sustainable development. Biodiversity is part of our daily lives and livelihood, and constitutes resources upon which families, communities, nations and future generations depend.
Every country has the responsibility to conserve, restore and sustainably use the biological diversity within its jurisdiction. Biological diversity is fundamental to the fulfilment of human needs. An environment rich in biological diversity offers the broadest array of options for sustainable economic ability, for sustaining human welfare and for adapting to change.
Loss of biodiversity has serious economic and social costs for any country.
The experience of the past few decades has shown that as industrialisation and economic development in the classical sense takes place, patterns of consumption, production and needs, change, straining, altering and even destroying ecosystems.
India, a mega-biodiversity country, while following the path of development, has been sensitive to needs of conservation and hence is still rich in biological resources. Ethos of conservation and harmonious living with nature is very much ingrained in the lifestyles of India’s people.
Science Fair Project # 2. Magnitude of Biodiversity:
The foundation for assessing the importance of biodiversity is an inventory of how many species exist and which species exist where. At the global level the plants and vertebrates are relatively well known. Erwin (1982), for example, suggests as many as 30 million species in total, with most un-described species living in tropical forests.
The known and described number of species of all organisms on the earth is between 1.7 and 1.8 million which is fewer than 15 per cent of the actual number’. About 61 per cent of the known species are insects. Only 4650 species of mammals are known to biological science. A large number of plant species (2, 70,000) and vertebrates are known.
But the fact remains that basic knowledge of the organisms that make up most ecosystems, especially in the tropics is inadequate. Information about bacteria, viruses, protists and Archaea is only fragmentary.
For convenience, many assume that about 10 million species exist, though the final figure is likely to be 30-50 million.
Given these limitations, the following table 14.1, represents a summary of the current state of knowledge:
However, new species are being discovered faster than ever before due to the efforts of Global Biodiversity Information Facility and the Species, 2000. The approximate number of species is being mentioned in the (table 14.2).
The number of plant and animal species in different groups recorded in India are given in (table 14.3)
India has 47,000 species of flowering and non-flowering plants representing about 12 per cent of the recorded world’s flora. Out of 47,000 species of plants, 5,150 are endemic and 2532 species are found in the Himalayas and adjoining regions and 1,782 in the peninsular India. India is also rich in the number of endemic faunal species it possesses.
Science Fair Project # 3. Gradients of Biodiversity:
Biodiversity-varies with change in latitude or altitude. When one moves from high to low latitudes (i.e., from the poles to the equator), the biodiversity increases.
In the temperate region, the climate is severe having short growing period for plants. On the other hand, in tropical rain forest the conditions are favourable for growth of plants throughout the year. Favourable conditions are helpful for speciation, and large number of species develop and grow.
The mean number of species of vascular plants per 0.1 ha sample area in tropical rain forests varies from 118-236, while in temperate zones, this range is 21-48 species.
Such a correlation between diversity and latitude is also found for a variety of several other taxa, such as ants, birds, butterflies, moths, etc.
In the similar way, there is a decrease in species diversity from lower to higher altitudes on a mountain. Increase of 1000 metres in altitude results in a temperature drop of about 6.5° C. Such temperature drop and seasonal variability at higher altitudes are responsible for lowering the diversity.
The latitudinal and altitudinal gradients of species diversity are two master gradients. To some extent regional and taxa-related gradients also affect biodiversity. It is expected that prevalence of more complex and heterogeneous environment makes the flora and fauna more diverse and complex.
Science Fair Project # 4. Uses of Biodiversity:
Humans derive many direct and indirect benefits from biological diversity. All our food comes from wild species brought into domestication. Most of our medicines, pharmaceutical, fibres, rubber and timber come from biological resources.
The biodiversity also provides many ecological services free of charge that are responsible for maintaining ecosystems. Our water is supplied by one of nature’s most important processes, called the ‘hydrological cycle’. Forested watersheds provide clear, high-quality water for domestic or agricultural use, while healthy rivers provide water, transport and fish.
Source of Food and Improved Varieties:
Biodiversity has direct consumptive value in agriculture.
In modem agriculture, biodiversity is used as follows:
(i) As a source of new crops
(ii) As a source material for breeding improved varieties, and
(iii) As a source new biodegradable pesticides.
Approximately 80,000 edible plants have been used at one time or another in human history, of which only about 150 have even been cultivated on a large scale. Today a mere 10 to 20 species provide 80 to 90 per cent requirements of the world.
Over half of human nutrition is provided by the three major carbohydrate crops, i.e., rice, wheat and maize. Fats, oils, fibres, etc., are other uses for which many new species are to be investigated.
Continuous research, often drawing on wild species, is therefore essential to maintain the productivity of the plants that provide us food. The commercial, domesticated species are crossbred with their wild ancestors to improve their traits.
Genes of wild species are used to confer new properties, such as disease and pest resistance or increased yield in new domesticated varieties.
For example rice (Oryza sativa) grown in Asian countries is protected from the four major diseases by genes received from a wild rice Indian species, i.e., Oryza nivara.
In India, many rural communities, particularly the tribals obtain considerable part of their daily food from the wild plants. Some examples are: Ceropegia bubosa in Central India and Western Ghats; Codonopisis ovata in Himalayan region; Ardisia and Meliosma pinnata in the North-east; Cicer microphyllutn in Kashmir and Sesuvium in Coastal areas.
On the other hand, a variety of faunal species, such as insects, molluscs, spiders, wild herbivores are consumed by many tribal and non-tribal communities in India.
Drugs and Medicines:
At one time, nearly all medicines were derived from biological resources. Even today they remain vital and as much as 67 to 70 per cent of modern medicine are derived from natural products.
In India, almost 95 per cent of the prescriptions are plant-based in the traditional systems of Ayurveda, Unani and Sidha. Many indigenous medicines also utilise medicines and their parts or extracts as remedies for various diseases.
Examples of plant-derived substances developed into valuable drugs are: Morphine obtained from Papaver somniferum and used as an analgesic; Quinine obtained from Cinchona ledgeriana, used for treatment of Malaria, and Taxol, an anticancer drug obtained from the bark of yew tree (Taxas baccata, T.brevifolia).
Botanochemicals. Many plants are also used for the manufacture of hundreds of synthetic products, which are called ‘botanochemicals’.
Aesthetic and Cultural Benefits:
Biodiversity has also great aesthetic value. Diverse habitats and species have non- consumptive use-value. Examples of aesthetic benefits include ecotourism, bird watching, wildlife, pet keeping, gardening, recreation and scientific research.
Many plants, animals and their parts are used in rituals all over the country. In a majority of Indian villages and towns, plants like Ocimum sanctum (Tulsi), Ficus religiosa (Pipal), F. bengalensis (Bargad), etc., are considered sacred and worshipped by the people.
Flowers of Hibiscus, Datura and Euphorbia, leaves of Aegle marmelos (Bel), Eragrostis cynasuroides (Kusa grass), rice, til, chenopods sacred, odorous roots of Dolomiaea macrocephala (Dhup) are used in rituals.
Besides, sacred values are attached to entire ecosystems, for example, patches of forests were believed to be the abode of demigods and are used only for prayers and rituals. Many ‘sacred groves’ exist in different parts of our country.
Several birds, snakes and other animals are treated sacred and worshipped.
Ecosystem Services:
The indirect use-value of biodiversity includes ecosystem process of biological diversity, which provides valuable ecological services to the biosphere.
For example, the ecosystem’s ability to absorb pollution, maintain soil fertility and microclimates, recharge groundwater and other invaluable services. These services include maintenance of gaseous composition of the atmosphere, climate control by forests and oceanic systems, natural pest control, pollination of plants by insects and birds, formation and protection of soil, conservation and purification of water, and nutrient cycling, etc.
The above mentioned ecosystem services have been valued in the range of 16 to 54 trillion US dollars per year.
Science Fair Project # 5. Levels of Biodiversity:
1. Genetic Diversity:
Genetic diversity is the sum total of genetic information, contained in the genes of individuals of plants, animals, and microorganisms that inhabit the earth. Each species, stores an immense amount of genetic information.
For example, the number of genes is about 450-700 in Mycoplasma; 4000 in Escherichia coli; 13,000 in Drosophila melanogaster, 32,000-50,000 in Oryza saliva and 35,000 to 45,000 in Homo sapiens.
The Characteristics of Genetic Diversity are as follows:
Genetic diversity refers to the variation of genes within species. The differences could be in alleles, i.e., different variants of same genes; in entire genes, i.e., the traits that determine particular characteristics or in chromosomal structures.
The genetic diversity enables a population to adapt to its environment and to respond to natural selection. On the other hand, if a species has more genetic diversity, it can adapt better to the changed environmental conditions.
Lower diversity in a species leads to uniformity, for example, in large monocultures of genetically similar crop plants. This may be an advantage when increased crop production is considered, whereas this may be a problem when a pest or pathogen attacks the crop field, and the whole crop is threatened.
The amount of genetic variation is the basis of speciation, i.e., evolution of new species. It has a key role to play in the maintenance of diversity at species and community levels.
The total genetic diversity of a community will be greater if there are many species, as compared to an area with few species. Genetic diversity within a species often increases with environmental variability.
2. Species Diversity:
Species diversity refers to the variety of living organisms on earth and has been variously estimated to be between 5 and 50 million or more, though only about 1.4 million have actually been described.
Species are distinct units of diversity, and each unit plays a specific role in an ecosystem. Thus, loss of species has consequences for the whole ecosystem.
Species diversity refers to the variety of species within a region.
Species richness or the number of species per unit area, denotes the measure of species diversity. The number of species increases with the area of the site, that is greater the species richness, greater is the species diversity. On the other hand, number of individuals among the species may also vary, resulting into differences in evenness, or equitability and consequently in diversity.
Here the example of three sample areas may be quoted:
a. The sample area 1, consists of three species of birds. Two species are represented by one individual each, while the third species has four individuals.
b. The sample area 2, also consists of three species, here, each species is represented by two individuals. This sample area exhibits greater evenness, and there are equal chances for a species being represented in a sample. The sample area 2 is more diverse than sample area 1.
c. The sample area 3, depicts the presence of an insect, a mammal and a bird. This sample area is considered most diverse, as it comprises of taxonomically unrelated species.
This example shows, there are equal number of species in each sample area, i.e., samples 1, 2 and 3, but having varying number of individuals per species.
However, in nature, both the number and kind of species, as well as the number of individuals per species vary, which result in greater diversity.
3. Community and Ecosystem Diversity:
Ecosystem diversity is related to the variety of habitats, biotic communities, and ecological processes in the biosphere, as well as the tremendous diversity within ecosystems in terms of habitat differences and the variety of ecological processes.
Diversity at the level of community and ecosystem has been divided into three categories:
a. Alpha Diversity: (= within community diversity):
This refers to the diversity of organisms sharing the same community or habitat.
A combination of species richness and equitability or evenness is used to represent diversity within a community or habitat. Species frequently change when habitat or community changes.
b. Beta Diversity: (= between-community diversity):
This refers the rate of replacement of species along a gradient of habitats or communities. In beta diversity, there are differences in species composition of communities along environmental gradients, e.g., altitudinal gradient, moisture gradient, etc. Greater the dissimilarity between communities, higher is the beta diversity.
c. Gamma Diversity:
This refers to the diversity of the habitats over the total landscape or geographical area.
Characteristics of Ecosystem Diversity:
In ecosystem diversity there are a number of ecological niches, trophic levels and various ecological processes that sustain energy flow, food needs and the recycling of nutrients.
Ecosystem diversity has a focus on various biotic interactions and the role and function of keystone species.
However, the diverse communities are functionally more productive and stable, even under environmental stresses, such as dry or drought conditions.
Science Fair Project # 6. Major Threats to Biodiversity:
1. Habitat Loss and Fragmentation:
The destruction of habitats is the primary reason for the loss of biodiversity. This erosion of biodiversity is largely due to habitat loss caused by the expansion of various development projects, such as mines, dams, roads and canal construction.
When people cut down trees, fill a wetland, plough a grassland or bum a forest the natural habitat of a species is changed or destroyed. Such changes can kill or force out many plants, animals and microorganisms. These changes also disrupt complex interactions among the species.
Habitat loss leads to the fragmentation of continuous stretches of land and consequently fragments wildlife populations inhabiting them. These small populations are increasingly vulnerable to inbreeding depression, high infant mortality, susceptibility to environmental stochasticity and in the long run possibly to extinction.
Apart from the primary loss of habitats, there are many other problems contributing to the loss and endangered status of several plant and animal species. Habitat degradation can lead to declines in primary food species for wildlife.
Poaching is another threat as one of the primary reasons for extinction of species such as the tiger.
Population pressures, such as collection of fuel-wood and fodder, and grazing in forests by local communities also take their toll on the forests and consequently its biodiversity.
Other minor factors include fire, and natural calamities like droughts, diseases, cyclones and land-slides.
It is estimated that, after independence, the country has lost 4,696 million ha of forest land to non-forestry purposes.
2. Disturbance and Pollution:
Communities are affected by natural disturbances, such as fire, tree fall, landslides and defoliation by insects.
Anthropogenic disturbances differ from natural disturbances in intensity, rate and spatial extent. For example, man by using fire more frequently may change species richness of a community.
The new anthropogenic impacts may be large number of synthetic compounds, massive releases of radiations by nuclear projects, and spill-over of oil in sea. These impacts may lead to a change in the habitat quality.
Over exploitation of natural resources, such as fishing by boats, mechanical catching of other animal species, etc., are serious threats to wildlife. Disturbance in migratory routes of several fishes, due to construction of dams, etc., hence they are not able to reach their spawning grounds and face extinction.
Pollution is also responsible for reduction and elimination of populations of sensitive species. For example, pesticide linked decline of fish-eating birds and falcons.
Lead poisoning of water is also a cause of mortality of many species, such as ducks, swans and cranes, as they take in the spent shotgun pellets that fell into lakes and marshes. Eutrophication, i.e., nutrient enrichment of water bodies is also responsible for reduction of species diversity.
3. Introduction of Exotic Species:
New species that enter a geographical region are called exotic or alien species. The invasion of such species may cause disappearance of native species through changed biotic interactions. The invasion of exotic species is considered second one to habitat destruction as a major threat to extinction of species.
Exotic species have more effective impact in island ecosystems, which give shelter to the world’s threatened biological diversity.
Examples are as follows:
(i) An exotic species Lantana camara has invaded many forest lands in different parts of our country, and strongly competes with the native species.
(ii) On the other hand water hyacinth (Eichhornia crassipes), an exotic aquatic species, clogs rivers, lakes and village ponds in different parts of India and several other tropical countries, which threaten, the survival of several native aquatic species.
(iii) Nile perch, an exotic predatory fish has been introduced into Lake Victoria of South Africa, where this has threatened the entire ecosystem of the lake, and eliminated several native species of small fish, e.g., Cichild fish species.
(iv) Periplaneta americana (American cockroach) has threatened the existence of native cockroach, i.e., Blatta orientalis.
(v) Parthenium hysterophorus has threatened several native herbs and shrubs of this country.
(vi) Goats and rabbits introduced in the islands of Indian and Pacific oceans are destroying the habitats of several plants, birds and reptiles.
4. Extinction of Species:
Extinction has been a fact of life since life first emerged. The present few million species are the modem-day survivers of the estimated several billion species that have ever existed. All past extinctions have occurred by natural processes, but today humans are the main cause of extinction.
The rapid destruction of the world’s most diverse ecosystems, especially in the tropics, has led most experts to conclude that perhaps a quarter of the earth’s total biological diversity is at serious risk of extinction during the next 20-30 years. By many indications, the world is already experiencing extinction rates of greater scale and impact than at any previous time in the earth’s history.
More species than even before are threatened with extinction, with thousands, mostly insects, disappearing each year.
There are three main types of extinction processes:
a. Natural Extinction:
With the change in environmental conditions, some species become extinct, while others, which are more adapted to changed conditions, take their place. This type of extinction of species which took place in the geological past at a very slow rate, is called natural extinction.
b. Mass Extinction:
As we know, there have been several periods in the geological history of earth when large number of species disappeared because of catastrophes. This kind of extinction is called ‘mass extinction’. Such mass extinctions occurred in millions of years.
c. Anthropogenic Extinction:
All past extinctions occurred either by natural or mass extinctions, but today humans are the main cause of extinctions. Today an alarming number of species are disappearing from the surface of earth due to irresponsible human activities. This man- made extinction of species represents a very severe depletion of biodiversity, particularly because this occurs within a short period of time.
It has been estimated at World Conservation Monitoring Centre (WCMC), that 533 species of animals (mostly vertebrates) and 384 species of plants (mostly angiosperms) have become extinct since 1600 AD. More species have gone extinct from the islands than from the mainland or oceans. The current rate of extinction of species is 1000 to 10,000 times higher than the background rate of extinction.
Some interesting observations about the current rate extinction of species are as follows:
i. From ten high-diversity localities in tropical forests which cover about 300,000 sq. km, some 17,000 endemic plant species and 350,000 endemic animal species are threatened and could be lost in near future.
ii. The tropical forests alone are losing about 14,000 to 40,000 species per year, which comes about 2-5 species per hour.
iii. It is estimated that by the end of twenty first century, if the current rate continues, the earth will lose up to fifty per cent of the species.
5. Susceptibility to Extinction:
The characteristics of species that make them susceptible for extinction are as follows:
a. Large Body Size:
Many animals are large-sized, e.g., Bengal tiger, lion and elephant.
b. Small Population Size and Low Reproductive Rate:
This characteristic of species is responsible for susceptibility to extinction, e.g.. Blue whale and Giant panda.
c. Feeding at High Trophic Levels in the Food Chain:
This characteristic also makes the animals susceptible to extinction. The examples are; Bengal tiger and Bald eagle.
d. Fixed Migratory Routes and Habitat:
Such routes cannot be changed, if any interruption occurs that leads towards extinction. The examples are; Blue whale and Whooping crane.
e. Localised and Narrow Range of Distribution:
This characteristic also makes the species susceptible to extinction, e.g., woodland caribon and many island species.
Science Fair Project # 7. Hot Spots of Biodiversity:
Norman Myers developed the hot spots concept in 1988 to designate priority areas for in situ conservation.
Biodiversity hot spots are areas that are unusually rich in species, most of which are endemic, and are under a constant threat of being overexploited.
The main criteria for determining a hot spot are:
(i) Number of endemic species (i.e., the species confined to that area, and not found elsewhere).
(ii) Degree of threat, which is measured in terms of habitat loss. Among the 25 hot spots in the world, two are found in India.
These are two distinct areas:
(i) The Eastern Himalayas, and
(ii) The Western Ghats.
These hot spots extend into the neighbouring countries also. These areas are rich in angiosperms (flowering plants), also in reptiles, amphibians, swallow-tailed butterflies and some mammals. Most of the species are endemic.
Together these 25 sites of the world contain approximately 49,955 endemic plant species or 20 per cent of the worlds recorded plant species, in only 746,400 sq km or 0.5 per cent of the earth’s land surface.
i. Eastern Himalayas:
Phytogeographically, the Eastern Himalayas forms a distinct floral region and comprises Nepal, Bhutan, neighbouring states of east and north-east India, and a part of southwestern China.
The temperate forests are found at altitudes of 1780 to 3500 metres a.s.1. In the whole of Eastern Himalayas, there are an estimated 9000 plant species, with 3500, i.e., 39 per cent of them are endemic.
In India’s sector of the area, there occur 5800 plant species, approximately 2000, i.e., 36 per cent of them are endemic.
At least 55 flowering plants endemic to this area are recognised as rare, e.g., the pitcher plant (Nepenthes khasiana). The species of numerous primitive angiosperm families such as Magnoliaceae and Winteraceae, and primitive genera of plants, like Magnolia and Betula are found in Eastern Himalayas.
The area is also rich in wild relatives of plants of economic significance, such as rice, banana, citrus, ginger, chilli, jute and sugarcane. The region is regarded as the centre of origin and diversification of commercially important palms, like coconut, arecanut, palmyra palm, sugar palm and wild date-palm.
As regards faunal diversity, 63 per cent of the genera of land mammals in India are known from this area, e.g., golden langur from Assam Bhutan region, and Namdapha flying squirrel from Arunachal Pradesh, indicating the species richness in the region.
ii. The Western Ghats:
The Western Ghats region is considered as one of the most important biogeographic zones of India, as it is one of the-richest centres of endemic species. This region lies parallel to the western coast of Indian peninsula for almost 1600 km in Maharashtra, Karnataka, Tamil Nadu and Kerala.
The forest at low elevation (500 m a.s.1.) are mostly evergreen, while those found at 500 to 1500 metres a.s.1. are generally semi-evergreen forests.
Due to varied topography and micro-climate, some areas within the region are considered to be active zones of speciation.
The region has 490 arborescent taxa, of which 308 species are endemic. About 1500 endemic species of dicotyledonous plants are reported from the Western Ghats. 245 species of orchids (monocotyledons) belonging to 75 genera are found in this region, of which 112 species in ten genera are endemic to this region.
As regards the fauna, as many as 315 species of vertebrates belonging to 22 genera are endemic, which include 12 species of mammals, 13 species of birds, 89 species of reptiles, 87 species of amphibians and 104 species of fish.
Nearly 235 species of endemic flowering plants are considered endangered.
Rare Fauna of the Region Includes:
Lion Tailed Macaque, Nilgiri Langur, Nilgiri Tahr, Flying Squirrel, and Malabar Gray Hornbill.
In the Wester Ghats, the Agasthyamalai hills, the Silent Valley, and the new Amambalam Reserve, are the main centres of diversity.