Ecosystem and Biodiversity

Ecosystem and Biodiversity

The ecosystem processes are controlled by diversity  and types of the plant, animal and microbial species living within a community. Biodiversity boosts ecosystem productivity where each species, no matter how small, has an important role to play. For example, a large number of plant species means a greater variety of crops; greater species  diversity ensures  sustainability for all life forms; more sustainability means healthy ecosystem; a healthy ecosystem can withstand and reover from disasters.

           “ At least 40% of the world’s economy and 80% of the needs of the poor are derived from biologcial 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.” The convention about Life on Earth.

   Human modifications to the living community and collective biodiversity of the arth can alter an ecosystem. The change in ecosystem will change the ecological functions. A healthy biodiversity provides a number of natural sevices for everyone that are vital to the well –being of human societies.

Eocsystem Services

(i)                  Soil  formation and prevention of soil erosion

(ii)                Nutrient recycling and storage

(iii)               Protection and conservation of water resources

(iv)              Pollutants breakdown and absorption

(v)                Climate stability

(vi)              Maintenance of ecosystems

(vii)             It provides biological resources, such as

·         Food

·         Medicinal resources and drugs

·         Wood products

·         Breeding stocks, population reservoirs

·         Diversity in genes

     (Viii)       It has social benefits

Biodiversity and Human Health

Biodiversity and Human Health

 Ecosystem provides the life support systems for all life; in additon to that, it purifies air and fresh water, binds and detoxifies poisonous substance, breaks down wates and recycles intrients on land and in the oceans, pollinates the crops  and natural vegetation, makes soil fertile and stores carbon.

·         Biodiversity supports food security, dietary health and livelihood sustainability: Ecosystem provides the fountation of crop development and food security and promotes resistance  and resilience to environmental stresses including pest and diseases of crops and livestock. Diets based on a diversity of food species promote health and can help to protect against diseas by addressing the problem of micronutrients and vitamin deficiencies. Loss of agricultural biodiveristy can therefore threaten health, livelihood sustainability an dour future  security of food and nutriton.

·         Biodiveristy provides important resources for medical research: Study of wildlife  anatomy, physiology and biochemistry can lead to important developments in human medicines. Examples of species of interest to medical science include hears ( for insights into osteoporosis, cardio-vascular disorder, renal disease and diabetes), sharks (osmoregulation and immunlogy) and crabs (ophthamology and molecular cell biology).

·         Biodiversity provides important resources for traditonal and modern medicine:  Modern drugs from wild species include Inter alla pain killer (Zinconitide from cone snail toxin), cardiac drugs (Lanoxin from digitalis plants) and treatment for diabetes (Exanitide from lizards).

Biodiversity and Economics

Biodiversity and Economics

In July 2010; the first Global Biodiversity symposium in London explored the role of biodiversity in business opportunities and risks. Industry  is broadly interested in the judicious use of natural resources with operational profitability, without adversely affecting biodiversity. Biodiversity is fundamental to economics. The G8 nations, together with 5 major emerging economies ( China, India, South Africa, Brazil and Mexico ) use almost three –quarters of earth’s bio-capacity. An estimated 40% of world is dependent on biological products or processes.

Biodiversity and Agriculture

About 80% of human’s food supply comes from just 20 kinds of plants; humans use at least 40,000 species for food, shelter and clothing. Crop diversity aids recovery when the dominant cultivar is attacked by a disease or predator. In the past, Irish Potato blight of 1846 was due to plantation of two potato varieties 6,273 varieties were screened for resistance to rice grassy stunt virus; only one resistant indian variety was selected and crossed with  other varieties. Monoculture was a contributing factor to several agricultural disasters. Bees provide enormous benefits for humankind and agriculture. It is the primary species that fertilizers food producing plants. The interdependence between bees, human and agriculture  is very crucial as summarized by researcher.

Threats to Biodiversity

Threats  to Biodiversity

Habitat destruction    The tropical rain forest destruction is mainly due to habitat destruction. The causative factors responsible for habitat destruction are :

·          Overpopulation: it is a condition where an organism number exceeds the carrying capacity of its habitat. This term is used for human population. Overpopulation is the ratio of population to available sustainable resources.

·         Deforestation: It is the removal of a forest and the land is used for other purposes. It leads to multiple environmental problems at atmospheric, hydrological  and soil level which ultimately affect the biodiversity. It causes extinction of many species.

BIODIVERSITY

BIODIVERSITY

Biodiversity referes to the variety and abundance of living  organisms living in a particular region. It has a magnitude that is beyond any limit. The exact number of species present at a global level is still ambiguous. The number may vary from 10 to 100 million,  and is a product of 4 billion years  evolution. The term biological diversity was used first by wildlife scientist and conservationist  Ramond F. Dasmann is the year 1968. He wrote a book “ A Diffferent kind of Country”  advocating conservation. The term biological diversity was contracted to biodiversity; it was  coined by W.G. Rosen in 1985. Biodiversity is not easy to quantify precisely but various ecological indicators, such as, number of species in a given area ae used  to quantify different aspects of biodiversity. It is important for organism interactions and each plays a role in the web of life. Biodiversity is very crucial  for human survival. Although it is late, people now value biodiversity for many reason:

·         Human depends on other species for food, fiber and medicine.

·         Species are necessary for the functioning of ecosystems and the many benefits and services those ecosystems provide to humanity.

Atoms combine to form molecules

Atoms combine to form molecules

 The characteristics of molecules and their organization in a cell up to speciation are discussed in the biology section. This chapter includes interaction at population and the levels above it.

Population Ecology

Population is a group of organisms of the same species that live in the same area at the same time. Certain principles govern the growth and sustainability of populations over time. Ecological interactions start within and between populations.

     Each population has its own gene pool and range of traits. It also has a characteristic size, density, and distribution pattern and age structure. Environmental conditions and species interaction influence these characteristics. Population size is generally an out -come of births, deaths, immigration and emigration. As long as the per capita birth rate remains even slightly above per capita death rate, a population can grow exponentially. Resources is short supply put limits on the growth of population. The maximum number of individuals of a population that can be sustained indefinitely be the resources in a given environment is referred as carrying capacity.

Biosphere

Biosphere

The biosphere includes the earth’s water, the lower atmosphere and the uppermost portions of its crust in which organisms live. Energy flows one way through the biosphere and materials move through  it on a grand  scale to influence ecosystems everywhere. The distribution  of species through the biosphere is an outcome of the earth’s history, topography, climate and  interactions among species. The average weather conditions., including temperature, humidity, wild velocity, cloud cover and rainfall over time tells the climate. Climate variation  due to differences in  the amount of solar radiation reaching equatorial and polar regions, the earth’s daily rotation and annual oceans and the sun, the distribution of continents and oceans and the elevation of land masses. Interacting climate factor produce the prevailing winds and ocean currents, which shape global weather patterns. The weather affects soil composition and water availability, which affects the growth and distribution of primary producers in the ecosystems.

Aquatic Biomes

Aquatic Biomes   Water provinces cover more than 72 per cent of the earth’s surface. They include standing fresh water (such as lakes), running fresh water  (such as streams), as well as the ocean and seas around the world. 

All aquatic ecosystems show gradients in light penetration, water temperature, salinity and dissolved gases. These factors vary daily and seasonally. Thus the primary productivity also varies in the aquatic ecosystems. Estuaries , internal zones,  rocky and sandy shores, tropical reefs and regions of the open ocean are major marine ecosystems. 

Estuaries are the areas where freshwater streams or rivers merge with the ocean. The mixing of water  creates a unique ecosystem . Microflora like algae, and macroflora such as seaweeds, marsh grasses and mangrove trees ( only in the tropics) can be found here. 

Biomes

Biomes

Some parts of the art have more or less the same kind of abiotic and biotic factors spread over a large are, creating a typical ecosystem over that area. Such major ecosystems are termed as biomes.

               An ecologist recognises a number of large ecological units  called biomes, which are based on the growth forms of the dominant vegetation. The distribution of terrestrial biomes is determined primarily by temperature and precipitation, but is also influenced by soil fertility and fire. Each biome is more or less isolated by oceans, mountain ranges or desert barriers. This geographical isolation tends  to restrict gene flow between these biomes. As a result, each biome maintains a characteristic species of living organisms.

Terrestrial biomes   Seven categories of the earth’s major biomes arranged by distance from equator are listed below.

1.       Tropical rain /evergreen forest  occur near equator, receive an enormous amount of rain year round, temperature ranges between 25° C  - 29° C  year round  and are characterized by the growth of tall tress and lush vegetation. Animal  diversity is highest in trophical forests.

2. Savanna ( hot deserts) alo lie near the equator but experience lesser rain than tropical rain forests and sometimes have prolonged dry spells. Savannas are characterised by open grasslands with scattered tress and shrubs.

3. Deserts (Cold Desert ) are extremely dry biomes; hot deserts are hot yearn round, whereas cold deserts are hot only in the summer. Deserts are great biological interest due to the extreme behavioral , morphological  and physiological adaptations of plants and animals that live there.

4. Temperate grasslands receive less rainfall than savannas but more than  deserts; the soil in temperate grassland is rich, so they are well suited to agriculture. Large grazers and burrowing mammals are native to temperate grasslands.

Ecological pyramids

 Ecological pyramids :  An important feature of energy flow is that most of the energy going from one trophic level to the next, in a food chain and food we, dissipated into the environment as a result of the second law of thermodynamics. Ecological pyramids oft tern graphically represent the relative energy values of each trophic  level. There are three  main types pyramids – a pyramid of numbers, a pyramid of biomass and pyramid of energy.

 Ecosystem productivity:  The gross primary productivity (GPP) of an ecosytem is the rate at which energy is captured during photosynthesis in a given period of time. In  addition, a plant respires to provide energy for its won use; this acts as a drain on photosynthesis. Energy in plant tissues after celluar respiration has occurred is net primary productivity (NPP). Both GPP and NPP are expressed as energy per unit area per unit time. Humans consume (32%) far more of earth’s resources than any other of  animal species. If we want our planet to operate sustainable, we must share terrestrial photosynthetic product with other organisms.

Ecosystems

Ecosystems

A community and its physical environment is called its Ecosystem. An ecosystem is a biological  environment consisting of all the organism living in a particular area, as well as all the non- living (abiotic), physical components of the environment with which the organisms interact, such as air, soil, water and sunlight.

      Ecosystem is an open system with inputs, internal transfers and outputs of energy and nutrients.  Sunlight is the initial energy source for nearly all ecosystems. The different types of ecosytems are

(i)                  Natural ecosystem

(a)    Terrestrial ecosystem

(b)   Aquatic ecosystem

(c)    Lentic (lake, pond or swamp)

(d)   Lotic (river, stream or spring)

(ii)                 Artificial Ecosystems

The species that live and interact in an area constitute an ecological community.

Parasitism, Mutualism, Commensalism, Predation Predator-Prey interactions

Parasitism: Interactions in which one organsism is harmed, but the other benefits.  A parasite may weaken its host; it rarely kills it host. More than 100 parasites live in or on the human species. When it causes a disease and sometimes the death of host, it is known as pathogen. Crown gall diease, caused by a bacterium, occurs in many plants.

·         Mutualism: Interactions in which both participants are benefited. The interdependent association between nitrogen fixing bacteria of the genus rhizobium and legume, is an example. Another example is the association between reef building coral animals and microscopic alage. The symbiotic alga is called Zooxan- thellae. Mycorrhizae is such an association between fungi and roots of 80% plants.

·         Commensalism: Interactions in which one participant benefits but the other is unaffected , e.g; relationship between two insects; silverfish and army ants, relationship between a tropical tree and many epiphytes, smaller plants such as mosses, orchids  and ferms that live attahed to the bark of the tree’s branches. The  epiphytes anchor itself to the tree to obtain adequate light and watr not for obtaining nutrients rom the tree.

Predation Predator-Prey interactions

THE HIERARCHICAL STRUCTURE OF ECOLOGICAL SYSTEM

Landscape Ecology

Landscape ecology is a sub discipline of ecology that studies ecological processes that operate over large areas. A landscape ecologist examines the connections among ecosystem found in a particular region.

THE HIERARCHICAL STRUCTURE OF ECOLOGICAL SYSTEM

The different levels of biological organization include:

Universe

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Galaxies

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Solar Systems

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Earth

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Biosphere

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Biomes

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Ecosystems

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Communities

                                                    ↑                                          Ecology

Populations

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Species

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Organism

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Cell

ENVIRONMENTAL ECOLOGY, BIODIVERSITY AND CLIMATE CHANGE

ENVIRONMENTAL  ECOLOGY, BIODIVERSITY AND CLIMATE CHANGE

BIODIVERSITY:THE BIOLOGICAL PERSPECTIVE

 INTRODUCTION

 The biosphere is a global ecosystem. It includes the entire portion of the earth inhabited by life. In a boarder sense., biospheres are any closed, self- regulating systems. The term “ biosphere” was coined by geologist Eduard Suess in 1875. He defined biosphere as the place on earth’s surface where life dwells.

    The biosphere’s ecological context came from 1920, preceding the 1935 introduction of the term “ecosystems” by sir Arthur Tansley. Valdimir  I. Vernadsky defined ecology as the science of the biosphere. It is an interdisciplinary concept for integrating astronomy, geophysics, meteorology, biogeography, evolution, geology, geochemistry, hydrology and all life and earth sciences . the biosphere is a core concept with biology and ecology. Ecology provides a scientific context for evaluation environmental issues. To address environmental  issues. To address environmental problems, we need to understand the interaction of organisms and their environments. The science of ecology provides that understanding. It is important to communicate the scientific complexity of environmental issues.

Ecology

Ecology is the scientific study of the rich and varied interactions between organisms and their abiotic environment. In ecological studies, the environment encompasses both abiotic (  such as water, mineral nutrients, light , temperature) and biotic factors (living organism). Interactions between organisms and their environment is a two way process in which organisms influence and are influenced by their environment.  There are many reasons to care about ecology. Our lives are enriched by the fascinating interactions between the organisms. Watching a butterfly visiting a flower and bringing about pollination is worth seeing. Beyond simple curiosity, information from ecological sciences is needed to solve many practical problems. An understanding of ecology allows us to grow food, control pests and diseases and deal with natural disasters such as flood, drought and earthquake.

BRANCHES OF ECOLOGY

1. Ecology and Evolution