Presented by Group 5

Jigar Desai (13) Purav Nanavati (38)Parthik Gosar (17) Ankita Rathi (42)Parth Joshi (23) Komal Shah (52)Jeba Arulraj (37) Saloni Zanzari (62)

Some basic definitions…..

Ecology is the scientific study of the relationships that living organisms have with each other and with their abiotic environment.

Ecosystems are composed of dynamically interacting parts including organisms, the communities they make up, and the non-living components of their environment.

Ecosystem processes, such as primary production, pedogenesis, nutrient cycling, and various niche construction activities, regulate the flux of energy and matter through an environment. These processes are sustained by the biodiversity within them.

Levels of organization of matter

Sub-atomic particles

Atoms

Mole-cules Proto-plasm

Cells

Tissues

Organs

Organ System

Organism

Populations

Commu-nities

Ecosystem

1. Abiotic components are such physical and chemical factors of an ecosystem as light, temperature, atmosphere gases(nitrogen, oxygen, carbon dioxide are the most important), water, wind, soil. These specific abiotic factors represent the geological, geographical, hydrological and climatological features of a particular ecosystem.

What are the components of an ecosystem?

Water, which is at the same time an essential

element to life and a milieu

Air, which provides oxygen, nitrogen, and carbon

dioxide to living species and allows the

dissemination of pollen and spores

Soil, at the same time source of nutriment and physical support. The salinity, nitrogen and phosphorus content, ability to retain water,

and density are all influential.

Temperature, which should not exceed

certain extremes, even if tolerance to heat is significant for some

species

Light, which provides energy to the ecosystem through photosynthesis

Natural disasters can also be considered

abiotic. According to the intermediate disturbance hypothesis, a moderate amount of disturbance

does good to increase the biodiversity

What are the components of an ecosystem?

What are the components of an ecosystem?

2. Biotic Components  The living organisms are the biotic components of an ecosystem. In ecosystems, living things are classified after the way they get their food. 

Biotic Components include the following -- 

Photoautotrophs are photosynthesizers such as algae and green plants that produce most of the organic nutrients for the biosphere. 

Autotrophs produce their own organic nutrients for themselves and other members of the community; therefore, they are called the producers. There are basically two kinds of autotrophs, "chemoautotrophs and photoautogrophs.

Chemoautotrophs are bacteria that obtain energy by oxidizing inorganic compounds such as ammonia, nitrites, and sulfides , and they use this energy to synthesize carbohydrates. . 

Heterotrophs, as consumers that are unable to produce, are constantly looking for source of organic nutrients from elsewhere.

What are the components of an ecosystem?

Detritivores - organisms that rely on detritus, the decomposing particles of organic matter, for food. Earthworms and some beetles, termites, and maggots are all terrestrial detritivores. 

Nonphotosynthetic bacteria and fungi, including mushrooms, are decomposers that carry out decomposition, the breakdown of dead organic matter, including animal waste. Decomposers perform a very valuable service by releasing inorganic substances that are taken up by plants once more 

What are the components of an ecosystem?

Flow of energy in an ecosystem is one way process. The sequence of organism through which the energy flows, is known as food chain.

What is Food Chain?

Tropic levels in a food chain

Producers

Consumers (i) Primary consumers (ii) Secondary consumers (iii) Tertiary consumers (iv) Quaternary consumers

Decomposers

Types of Food Chain

(i) Grazing Food Chain•The consumers utilizing plants as their food , constitute grazing food chain.

• This food chain begins from green plants and the primary consumer is herbivore.

• Most of the ecosystem in nature follows this type of food chain.Ex: grass => grasshopper => frogs => snakes=>falcon

(ii) Detritus food chain•This type of food chain starts from dead organic matter of decaying animals and plant bodies to the micro-organisms and then to detritus feeding organism and to otherpredators.

•The food chain depends mainly on the influx of organic matter produced in another system.

•The organism of the food chain includes algae, bacteria,fungi, protozoa, insects, nematodes etc.

Types of Food Chain

•The knowledge of food chain helps in understanding the feeding relationship as well as the interaction between organism and ecosystem.

•It also help in understanding the mechanism of energy flow and circulation of matter in ecosystem.

•It also helps to understand the movement of toxic substance and the problem associated with biological magnification in the ecosystem.

Significance of Food Chain 

FOOD WEBS

What is food web?Food web can be defined as, "a network of food chains which are interconnected at various tropic levels, so as to form a number of feeding connections amongst different organisms of a biotic community".It is also known as consumer-resource system.

•A node represents an individual species, or a group of related species or different stages of a single species.

• A link connects two nodes. Arrows represent links, and always go from prey to predator.

• The lowest tropic level are called basal species.

• The highest tropic level are called top predators.

•Movement of nutrients is cyclic but of energy is unidirectional and non-cyclic.

Important facts

Types of food web representation

•These food webs simply indicate a feeding relationship.

TOPOLOGICAL WEBS

•Bio-energetic webs, or flow webs, include information on the strength of the feeding interaction.

FLOW WEBS

•In interaction the arrows show how one group influences another.

INTERACTION WEB

• Soil food web• Aquatic food web• Food web in forest• Food web of grassland• Food web in terrestrial and aquatic ecosystem

Different food webs

Aquatic food web

Food web in forest

Grassland Food Web

Food web in terrestrial and aquatic ecosystem

•Food webs distinguish levels of producers and consumers by identifying and defining the importance of animal relationships and food sources, beginning with primary producers such as plants, insects and herbivores.

•Food webs are important tools in understanding that plants are the foundation of all ecosystems and food chains, sustaining life by providing nourishment and oxygen needed for survival and reproduction.

•The food web provide stability to the ecosystem.

Significance of Food Web

What causes ecosystem to change?? (Natural causes)

Cyclones &Hurricane

Volcano eruptions

Floods and famines

Natural forest fires

Oil spills

Pollution

Artificial fires

What causes ecosystem to change?? (man-made causes)

Examples of ecosystem changeThe extirpation of wolves in Yellowstone National Park led to over-browsing of aspen and willows by elk, and restoration of wolves has allowed the vegetation to recover.

The reduction of lions and leopards in parts of Africa has led to population outbreaks and changes in behavior of olive baboons, increasing their contact with people and causing higher rates of intestinal parasites in both people and baboons.

A rinderpest epidemic decimated the populations of wildebeest and other ungulates in the Serengeti, resulting in more woody vegetation and increased extent and frequency of wildfires prior to rinderpest eradication in the 1960s.

Dramatic changes in coastal ecosystems have followed the collapse and recovery of sea otter populations; sea otters maintain coastal kelp forests by controlling populations of kelp-grazing sea urchins.

The decimation of sharks in an estuarine ecosystem caused an outbreak of cow-nosed rays and the collapse of shellfish populations.

Natural Disasters and Environmental Change

Natural Disasters and Environmental Change

Ecosystems are constantly changing. The plants and animals living in an ecosystem change the ecosystem just by going about

their daily lives. Over time, even bigger changes can happen.

Ecological Succession

The gradual process of change in an ecosystem is called ecological succession.

There are two types of ecological succession.

Natural Disasters and Environmental Change

Primary succession is succession that happens where an ecosystem was not present before. Another example is an ecosystem that develops in a very rocky area or on

a sand dune.

Secondary succession is another type of ecological succession. Secondary succession occurs where an

ecosystem has previously existed. For example, secondary succession occurs when a lake

ecosystem gradually fills in and grows into a forest.

Secondary succession also happens in ecosystems that have been disrupted by humans or by natural disasters. Land development can cause secondary succession. So

can natural disasters such as earthquakes, volcanoes, and fires.

Natural Disasters and Ecosystems

• One example of a natural disaster and how it changed the surrounding environment is the eruption of Mt. St. Helen's in Washington.

• http://youtu.be/Y8vOaQUSGZU

• http://youtu.be/4RsMyVavT2Q

Fires and Ecological Succession

There are some types of ecosystems that stay healthy because of fires. In some parts of the country, wild fires are allowed to burn because they allow room for certain types of plants and trees to grow.

In fact, there are some types of trees that will not release their seeds unless they are exposed to very high temperatures.

In fact, there are some types of trees that will not release their seeds unless they are exposed to very high temperatures.

A fire allows some trees to be cleared in order for others to grow. This in turn provides food for organisms that need it.

Ecosystem stability

Resistance and resilience: the relationship between stability and sustainability

• Ecosystem stability is an important corollary of sustainability. Over time, the structure and function of a healthy ecosystem should remain relatively stable, even in the face of disturbance. If a stress or disturbance does alter the ecosystem is should be able to bounce back quickly

• Resistance - the ability of the ecosystem to continue to function without change when stressed by disturbance

• Resilience - the ability of the ecosystem to recover after disturbance.

Factors affecting stability:Disturbance frequency and intensity (how often and what kind of tillage)

Species diversity (intercropping or rotations), interactions (competition for water and nutrients from weed species), and life history strategies (do the species grow fast and produce many seeds or slow with few seeds)

Tropic complexity (how many functions are represented), redundancy (how many populations perform each function), food web structure (how do all of these groups interact)

Rate of nutrient or energy flux (how fast are nutrients and energy moving in and out of the system or input:output efficiency)

Conclusion

The ecosystem change can either recover from a disturbance or not. It’s easier to recover from a natural disturbances than man made disturbances

A concept related to ecosystem stability is the Intermediate Disturbance Hypothesis, which states that the highest levels of diversity are supported at intermediate levels of disturbance (frequency or intensity)

Ecosystems experiencing intermediate levels of disturbance, will have the highest diversity, the greatest redundancy, and, therefore, the greatest stability

In other words, stability can apply to the number of species in an area or the number of functions performed.