Biodiversity And Conservation Flashcards
What is the latitudinal gradient in biodiversity?
Species diversity decreases as we move away from the equator towards the poles.
Where do most species tend to be found?
Tropics (latitudinal range of 23.5°N to 23.5°S) harbour more species than temperate or polar areas.
How many species of birds are found in Colombia?
Colombia has nearly 1,400 species of birds.
How many species of birds are found in New York?
New York has 105 species of birds.
How many species of birds are found in Greenland?
Greenland has only 56 species of birds.
How many species of birds are found in India?
India has more than 1,200 species of birds.
How does the species diversity of tropical forests compare to temperate forests?
A tropical forest can have up to 10 times as many species of vascular plants as a temperate forest of equal area.
What is the biodiversity of the Amazonian rain forest?
The Amazonian rain forest is home to more than 40,000 species of plants, 3,000 of fishes, 1,300 of birds, 427 of mammals, 427 of amphibians, 378 of reptiles, and over 125,000 invertebrates.
What do scientists estimate about insect species in rain forests?
Scientists estimate that there might be at least two million insect species waiting to be discovered and named.
What hypothesis explains the greater biological diversity in tropics?
Speciation is generally a function of time; tropical latitudes have remained relatively undisturbed for millions of years.
What promotes greater species diversity in tropical environments?
Tropical environments are less seasonal, more constant, and predictable, which promotes niche specialization.
This leads to greater species diversity.
What is the relationship between species richness and area?
Species richness increases with increasing explored area, but only up to a limit. This relationship is a rectangular hyperbola.
The equation is log S = log C + Z log A.
What do the variables S, A, Z, and C represent in the species-area relationship equation?
S = Species richness, A = Area, Z = slope of the line (regression coefficient), C = Y-intercept.
What is the typical range of Z values for species-area relationships?
The value of Z typically lies in the range of 0.1 to 0.2 for various taxonomic groups.
This holds true across different regions and taxa.
What happens to the slope of the species-area relationship for very large areas?
For very large areas, the slope of the line is much steeper, with Z values ranging from 0.6 to 1.2.
What does a steeper slope in the species-area relationship indicate?
A steeper slope indicates a greater increase in species richness with area, as seen in frugivorous birds and mammals in tropical forests, where the slope is 1.15.
Does the number of species in a community matter for ecosystem functioning?
Ecologists have not been able to provide a definitive answer, but communities with more species tend to be more stable than those with fewer species.
What is the traditional belief about species-rich communities?
For many decades, it was believed that communities with more species are generally more stable.
What does the data show about extinctions across taxa?
Extinctions across taxa are not random; some groups, like amphibians, appear to be more vulnerable to extinction.
How many species worldwide are facing the threat of extinction?
More than 15,500 species worldwide are facing the threat of extinction.
What percentage of bird species face extinction?
12 percent of all bird species face the threat of extinction.
What percentage of mammal species face extinction?
23 percent of all mammal species face the threat of extinction.
What percentage of amphibian species face extinction?
32 percent of all amphibian species face the threat of extinction.
What percentage of gymnosperm species face extinction?
31 percent of all gymnosperm species face the threat of extinction.
How many episodes of mass extinction have occurred in the history of life on Earth?
There have been five episodes of mass extinction in the history of life on Earth.
How does the current extinction rate compare to pre-human times?
Current species extinction rates are estimated to be 100 to 1,000 times faster than in pre-human times.
What might happen if current extinction trends continue?
Nearly half of all species on Earth might be wiped out within the next 100 years.
What are the general consequences of loss of biodiversity?
Loss of biodiversity may lead to a decline in plant production, lowered resistance to environmental perturbations, and increased variability in ecosystem processes.
What are the four major causes of biodiversity loss?
The four major causes are habitat loss and fragmentation, overexploitation, pollution, and invasive species.
What is the most important cause driving species to extinction?
Habitat loss and fragmentation is the most important cause driving species to extinction.
What has happened to tropical rain forests in terms of area covered?
Tropical rain forests have decreased from covering more than 14 percent of the Earth’s land surface to no more than 6 percent.
What is the Amazon rain forest often referred to as?
The Amazon rain forest is referred to as the ‘lungs of the planet.’
What is a dramatic consequence of habitat fragmentation?
Habitat fragmentation affects mammals and birds requiring large territories and migratory animals, leading to population declines.
What happens when ‘need’ turns to ‘greed’ in terms of resource use?
When ‘need’ turns to ‘greed,’ it leads to overexploitation of natural resources.
What is over-exploitation of natural resources?
The excessive use of natural resources leading to species extinctions.
Which two species extinctions in the last 500 years were due to overexploitation by humans?
- Steller’s sea cow
- Passenger pigeon
What is the current status of many marine fish populations?
They are over harvested, endangering commercially important species.
What happens when alien species are introduced into an ecosystem?
Some become invasive, causing decline or extinction of indigenous species.
What was the impact of the Nile perch introduction in Lake Victoria?
It led to the extinction of more than 200 species of cichlid fish.
Name three invasive weed species that threaten native species.
- Carrot grass (Parthenium)
- Lantana
- Water hyacinth (Eicchornia)
What is the threat posed by the African catfish Clarias gariepinus?
It threatens indigenous catfishes in rivers.
What is co-extinction?
The extinction of a species that leads to the extinction of associated species.
Give an example of co-extinction involving fish.
Extinction of a host fish species results in the extinction of its unique parasites.
What are the three categories of reasons for conserving biodiversity?
- Narrowly utilitarian
- Broadly utilitarian
- Ethical
What are some direct economic benefits humans derive from nature?
- Food (cereals, pulses, fruits)
- Firewood
- Fibre
- Construction material
- Industrial products (tannins, lubricants, dyes, resins, perfumes)
What percentage of drugs sold worldwide are derived from plants?
More than 25 percent.
How many species of plants contribute to traditional medicines used by native peoples?
25,000 species.
What is bioprospecting?
Exploring molecular, genetic, and species-level diversity for economically important products.
What is the broadly utilitarian argument for conserving biodiversity?
Biodiversity plays a major role in ecosystem services provided by nature.
6
dwindling Amazon forest is estimated to produce
through
photosymthesis
20 per cent of the total oxygen in the earth’s atmosphere.
Can we put an economic value on this service by nature? You can get
some idea by finding out how much your neighborhood hospital spernds
on a cylinder of oxygen. Pollination (without which plants cannot give
us fruits or seeds) is another service
ecosystems provide through
pollinators layer - bees
bumblebees
costs of accomplishing pollination without help from natural
pollinators? There are other intangible benefits - that we derive from
nature-the aesthetic pleasures of walking through thick woods
watching
spring flowers in full bloom or waking up to a bulbul’s song in the
morning. Can we put a price tag on such things?
The ethical argument for conserving biodiversity relates to what we
cwe to millions of plant. animal and microbe species with whom we share
this planet. Philosophically or spiritually
we need to realise that every
species has an intrinsic value
even if it may not be of cuTent or any
economic value to us. We have a moral duty to care for their well-being
and pass on our biological legacy in good order to future generations.
I5.2.2 How do we conserve Biodiversity?
When we conserve and protect the whole ecosystem
its biodiversity at all
levels is protected - we save the entire forest to save the tiger. This approach
is called in situ (on site) conservation. However
when there are situations
where an animal or plant is endangered or threatened (organisms facing
a very high risk.of extinction in the wild in the near future) and needs
Lurgent measures to save it from extinction
ex situ (off site) conservation.
is the desirable approach.
In situ conservation- Faced with the conflict between development and
conservation
many nations find it unrealistic and economically not feasible
to conserve all their biological wealth. Invariably
the number of species
waiting to be saved fromn extinction far exceeds the conservation resources
available. On a global basis
this problem has beern addressed by eminent
conservationists. They identified for maximum protection certain
“biodiversity hotspots’ regions with very high levels of species richness
and high degree of endemism (that is, species confined to that region
and not found anywhere else). Initially 25 biodiversity hotspots were
identified but subsequently nine more have been added to the list.
bringing the«total number of biodiversity hotspots in the world to 34.
These hotspots are also regions of accelerated habitat loss. Three of
these hotspots - Western Ghats and Sri Lanka, Indo-Burma and
Himalaya - cover our country’s exceptionally high biodiversity regions.
Although all the biodiversity hotspots put together cover less than
2 per cent of the earth’s land area. the number of species they collectively
What is the impact of strict protection on biodiversity hotspots?
Strict protection of biodiversity hotspots could reduce ongoing mass extinctions by almost 30 percent.
How many biosphere reserves, national parks, and wildlife sanctuaries does India have?
India has 14 biosphere reserves, 90 national parks, and 448 wildlife sanctuaries.
What cultural traditions in India emphasize nature protection?
India has a history of religious and cultural traditions that emphasize the protection of nature, including sacred groves.
Where can sacred groves be found in India?
Sacred groves are found in Khasi and Jaintia Hills in Meghalaya, Aravalli Hills of Rajasthan, Western Ghats of Karnataka and Maharashtra, and Sarguja, Chanda, and Bastar areas of Madhya Pradesh.
What is ex situ conservation?
Ex situ conservation involves taking threatened animals and plants out of their natural habitat to protect them in special settings.
What facilities serve the purpose of ex situ conservation?
Zoological parks, botanical gardens, and wildlife safari parks serve the purpose of ex situ conservation.
What advancements have been made in ex situ conservation?
Advancements include preserving gametes using cryopreservation, fertilizing eggs in vitro, and propagating plants using tissue culture methods.
What is the significance of the Convention on Biological Diversity?
The Convention on Biological Diversity, held in 1992, called upon nations to take measures for biodiversity conservation and sustainable utilization.
What commitment was made at the World Summit on Sustainable Development in 2002?
At the 2002 World Summit, 190 countries pledged to achieve a significant reduction in the rate of biodiversity loss by 2010.
