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Biodiversity

Nov 01, 2019

Biodiversity - Definition

  • The number and variety of plants, animals and other organisms that exist in an ecosystem is known as biodiversity
  • It is a measure of the variety of organisms present in different ecosystems
  • The richness of biodiversity depends on the climatic conditions and area of the region
  • Biodiversity is the result of 3.5 billion years of evolution

Types of biodiversity

  • There are 3 types of biodiversity
  • GENETIC diversity: genetic variability or diversity within a species
  • SPECIES diversity:diversity between different species
  • Ecosystem diversity:diversity betweem different region

Genetic Diversity

Genetic diversity is the amount of variation in genetic material (DNA) within a species or within a population. The magnitude of variation in genes of a species increases with increase in size and environmental parameters of the habitat.
Genetic diversity has the following importance:
(i) It helps in speciation or evolution of new species;
(ii) It is useful in adaptation to changes in environmental conditions;
(iii) It is important for agricultural productivity and development

Species Diversity

  • It describes the variety in the number and abundance of the species within a region
  • To accurately determine species diversity, both the species richness, which is the number of different species, and the relative abundance, which is the number of individuals within each species, must be considered
  • The species richness depends largely on climatic conditions. 
  • When a species is confined entirely to a particular area, it is termed as endemic species

Ecosystem Diversity

  • It describes the assemblage and Interaction of spices living together and the physical environment of a given area
  • It relates varieties of habitats, biotic communities ecological processes in biosphere. It also tells about the diversity within the ecosystem. 
  • For example, the landscapes like grass lands, deserts, mountains etc. show ecosystem diversity
  • The ecosystem diversity is due to diversity of niches, trophic levels and ecological processes like nutrient cycling, food webs, energy flow, role of dominant species and various related biotic interactions.
  • Such type of diversity can generate more productive and stable ecosystems or communities capable of tolerating various types of stresses e.g. drought, flood etc.

Biodiversity : Distribution

  • Biodiversity is not evenly distributed, rather it varies greatly across the globe as well as within regions
  • Among other factors, the diversity of all living things (biota) depends on temperature, precipitation, altitude, soils, geography and the presence of other species. 
  • Diversity consistently measures higher in the tropics and lower in polar regions generally
  • Rain forests that have had wet climates for a long time, have particularly high biodiversity
  • Terrestrial biodiversity is thought to be up to 25 times greater than ocean biodiversity

Biodiversity Hotspots

  • A biodiversity hotspot is a region with a high level of endemic species that has experienced great habitat loss
  • While hotspots are spread all over the world, the majority are forest areas and most are located in the tropics
  • Colombia is characterized by high biodiversity, with the highest rate of species by area unit worldwide
  • It has the largest number of endemics (species that are not found naturally anywhere else) of any country
  • About 10% of the species of the Earth can be found in Colombia

Hotspots

  • 34 biodiversity hotspots have been identified. They once covered 15.7 percent of the Earth's land surface
  • 86 % of the hotspots' habitat has already been destroyed
  • The intact remnants of the hotspots now cover only 2.3 % of the Earth's land surface.

Loss of Biodiversity

  • The main cause of the loss of biodiversity can be attributed to the influence of human beings on the world's ecosystem
  • Escalating human population is a major cause of biodiversity loss
  • Most of the biodiversity loss has happened post Industrial Revolution through human activities 

Species Loss Rate

  • The planet has lost 52% of its biodiversity since 1970 according to a 2014 study by the World Wildlife Fund
  • The Living Planet Report 2014 claims that "the number of mammals, birds, reptiles, amphibians and fish across the globe is, on average, about half the size it was 40 years ago“
  • Of that number, 39% accounts for the terrestrial wildlife gone, 39% for the marine wildlife gone and 76% for the freshwater wildlife gone
  • Biodiversity took the biggest hit in Latin America 

Causes of Biodiversity Loss

  • Alteration and loss of the habitats: the transformation of the natural areas determines not only the loss of the vegetable species, but also a decrease in the animal species associated to them.
  • Introduction of exotic species and genetically modified organisms: species originating from a particular area, introduced into new natural environments can lead to different forms of imbalance in the ecological equilibrium. Refer to, “Introduction of exotic species and genetically modified organisms”.
  • Pollution: human activity influences the natural environment producing negative, direct or indirect, effects that alter the flow of energy, the chemical and physical constitution of the environment and abundance of the species;

Causes of Biodiversity Loss

  • Climate change: for example, heating of the Earth’s surface affects biodiversity because it endangers all the species that adapted to the cold due to the latitude (the Polar species) or the altitude (mountain species).
  • Overexploitation of resources: when the activities connected with capturing and harvesting (hunting, fishing, farming) a renewable natural resource in a particular area is excessively intense, the resource itself may become exhausted, as for example, is the case of sardines, herrings, cod, tuna and many other species that man captures without leaving enough time for the organisms to reproduce.

Loss of Biodiversity

  • Habitat loss and degradation
  • Habitat loss and degradation create the biggest single source of pressure on biodiversity worldwide
  • For terrestrial ecosystems, habitat loss is largely accounted for by conversion of wild lands to agriculture, which now accounts for some 30% of land globally
  • In some areas, it has recently been partly driven by the demand for biofuels

Climate Change

  • Climate change is already having an impact on biodiversity, and is projected to become a progressively more significant threat in the coming decades
  • Loss of Arctic sea ice threatens biodiversity across an entire biome and beyond
  • The related pressure of ocean acidification, resulting from higher concentrations of carbon dioxide in the atmosphere, is also already being observed

Importance of Biodiversity

At least 40 per cent of the world’s economy and 80 per cent of the needs of the poor are derived from biological resources. In addition, the richer the diversity of life, the greater the opportunity for medical discoveries, economic development, and adaptive responses to such new challenges as climate change.

Biosphere Reserves

  • Biosphere reserves are areas comprising terrestrial, marine and coastal ecosystems. Each reserve promotes solutions reconciling the conservation of biodiversity with its sustainable use.
  • Biosphere reserves are nominated by national governments and remain under the sovereign jurisdiction of the states where they are located. Their status is internationally recognized.
  • There are 669 biosphere reserves in 120  countries, including 16 transboundary sites. They are distributed as follows:
  • 70 in 28 countries in Africa
  • 30 in 11 countries in the Arab States
  • 142 in 24 countries in Asia and the Pacific
  • 302 in 36 countries in Europe and North America
  • 125 in 21 countries in Latin America and the Caribbean.

Zones in a Biosphere Reserve

A biosphere reserve is divided into three zones: Core, buffer and manipulation.
(i) Core Zone:
In core or natural zone human activity is not allowed. This area is legally protected and undisturbed ecosystem.
(ii) Buffer zone:
The immediate surrounding area of core zone is buffer zone. Here limited human activities live like research, education and research strategy is permitted.
(iii) Manipulation zone:
Manipulation or transition zone is the outermost or peripheral area of biosphere reserve. With the cooperation of reserve management and local people several human activities like settlements, cropping, recreation, and forestry are carried out without disturbing the environment. Buffer zone has different parts like forestry, agriculture, tourism and restoration regions. 

Zones of Biosphere Reserve

Difference between Biospheres, National Parks, Wild Life Sanctuaries
Biosphere Reserves are the biggest entity among the three
The level of restriction in the increasing order is Biosphere Reserves, Wildlife Sanctuaries and National Parks
The Indian government has established 18 Biosphere Reserves, over 441 Wild Life sanctuaries and 102 national parks

Importance of Biosphere

1. Conservation:
Biosphere reserves conserve genetic resources, species, ecosystems and landscapes without uprooting inhabitants. Rather the traditional life style and traditional resources of the local people are maintained.
2. Development:
Sustainable economic, cultural, social and ecological developments are ensured.
3. Restoration:
Biosphere reserve helps to rebuild any damage caused to ecosystems and habitats.
4. Education and Research:
Biosphere reserve provides a lot of scientific information for specific scientific studies and research. Exchange of information on restoration, conservation and development of biosphere can be made at national and international levels.

India – Biosphere Reserves

  • The Indian government has established 18 Biosphere Reserves in India
  • They protect larger areas of natural habitat (than a National Park or Animal Sanctuary), and often include one or more National Parks, along with buffer zones that are open to some economic uses
  • Protection is granted not only to the flora and fauna of the protected region, but also to the human communities who inhabit these regions, and their ways of life. 

Biopiracy

  • The practice of commercially exploiting naturally occurring biochemical or genetic material, especially by obtaining patents that restrict its future use, while failing to pay fair compensation to the community from which it originates
  • Bioprospecting : The search for biological resources & accompanying indigenous knowledge for the purpose of commercial exploitation
  • A process of appropriation and commercialization of natural products ranging from plants and animals
  • Bioprospecting is legal but may promote biopiracy

Biopiracy

  • Biopiracy operates through unfair application of patents to genetic resources and traditional knowledge
  • Biopiracy is the theft or usurpation of genetic materials especially plants and other biological materials by the patent process 
  • example: use of indigenous knowledge of medicinal plants for patenting by medical companies without recognizing the fact that the knowledge is not new, or invented by the patenter
  • Biopiracy deprives the indigenous community to the rights to commercial exploitation of the technology that they themselves had developed

Columbian Exchange

  • The Columbian Exchange was the widespread transfer of plants, animals, culture, human populations, technology, and ideas between the Americas  (NEW World)  and the Old World in the 15th and 16th centuries, related to European colonization and trade after Christopher Columbus’s 1492 voyage
  • The contact between the two areas circulated a wide variety of new crops and livestock, which supported increases in population in both hemispheres, although diseases initially caused precipitous declines in the numbers of indigenous peoples of the Americas
  • Traders returned to Europe with maize, potatoes, and tomatoes, which became very important crops in Europe by the 18th century
  • The term was first used in 1972 by American historian Alfred W. Crosby in his environmental history book The Columbian Exchange. 

Biodiversity Conservation

  • Biodiversity conservation is about saving life on Earth in all its forms and keeping natural ecosystems functioning and healthy
  • Conservation is of two kinds :  In-situ conservation and  Ex-situ conservation
  • In-situ conservation, the conservation of species in their natural habitats, is considered the most appropriate way of conserving biodiversity.
  • Conserving the areas where populations of species exist naturally is an underlying condition for the conservation of biodiversity. That's why protected areas form a central element of any national strategy to conserve biodiversity
  • A protected area is a geographically defined area that is designated or regulated and managed to achieve specific conservation objectives. It may be set aside for the protection of biological diversity, and of natural and associated cultural resources and is managed through legal or other effective means. 
  • This includes national parks and nature reserves, sustainable use reserves (biospheres), wilderness areas and heritage sites

Ex-Situ Conservation

  • Ex-situ conservation is the preservation of components of biological diversity outside their natural habitats.  This involves conservation of genetic resources, as well as wild and cultivated or species, and draws on a diverse body of techniques and facilities.  Some of these include:
  • Gene banks, e.g. seed banks, sperm and ova banks, field banks;
  • In vitro plant tissue and microbial culture collections;
  • Captive breeding of animals and artificial propagation of plants, with possible reintroduction into the wild; and
  • Collecting living organisms for zoos, aquaria, and botanic gardens for research and public awareness.
  • Ex-situ conservation measures can be complementary to in-situ methods as they provide  an "insurance policy" against extinction
  • These measures also have a valuable role to play in recovery programs for endangered species

Convention on Biological Diversity(CBD)- 1993

The Convention on Biological Diversity (CBD), known informally as the Biodiversity Convention, is a multilateral treaty
The Convention has three main goals:
conservation of biological diversity (or biodiversity);
sustainable use of its components; and
fair and equitable sharing of benefits arising from genetic resources
In other words, its objective is to develop national strategies for the conservation and sustainable use of biological diversity. It is often seen as the key document regarding sustainable development
The Convention was opened for signature at the Earth Summit in Rio de Janeiro on 5 June 1992 and entered into force on 29 December 1993
It secured rights to control access to genetic resources for the countries in which those resources are located
One objective of the CBD is to enable lesser-developed countries to better benefit from their resources and traditional knowledge

Article Posted in: Academics
Tags: Education

Roshan Rawat

With more than 3 years of experience in tutoring students belonging to Competitive Exam and train students for the campus recruitment test in the engineering colleges. I try to cater to them all as per their requirements. My focus is particularly based on problem-based learning. I’m also associated with LearnPick for the last 6 years. I will teach whatever the students want to learn but I will teach them in a very simple way.  I’m also associated with LearnPick for the last 2 years.

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