Ecosystem – Structure and Function, Productivity andDecomposition
Very Short Answer Type Questions
Question. What does ‘R’ represent in the given equation for productivity in an ecosystem ?
GPP — R = NPP.
Answer : ‘R’ represents the loss of biomass due to respiration.
Question. All primary productivity is not available to herbivore. Give one reason.
Answer : All primary productivity is not available to a herbivore because a considerable amount of it is utilized by the plants itself in respiration.
Question. Write the equation that helps in deriving the net primary productivity of an ecosystem.
Answer : NPP = GPP – R
where, NPP : Net Primary Productivity.
GPP : Gross Primary Productivity.
R = Respiratory losses.
Question. What is secondary productivity?
Answer : Secondary productivity refers to the rate of formation of new organic matter by the consumers specially by the herbivores or primary consumers.
Question. How is ‘stratification’ represented in a forest ecosystem ?
Answer : Stratification is the formation of different layers (strata where vegetation is dense such as tropical rain forest). It represents vertical distribution of species at different levels.
There may be many strata such as long trees, medium trees, short tress, shrubs, herbs and ground flora etc. Trees occupy vertical strata, shrubs the second layer and herbs / grasses occupy the bottom layers.
Question. Why are green algae not likely to be found in the deepest strata of the ocean ?
Why are green plants not found beyond certain depth in ocean?
Answer : Green algae are not found beyond a certain depth in ocean because only about 1 percent of sunlight penetrates at this depth which is not sufficient for the plants to photosynthesize and thus grow and survive.
Question. Write a difference between net primary productivity and gross productivity.
Answer : Gross productivity – Rate of production of organic matter during photosynthesis.
Net primary productivity – Available biomass for the consumption of heterotrophs.
GPP – R = NPP.
Question. Why is an earthworm called detrivore ?
Answer : Earth worms are called detrivores because they break down the detritus i.e. the dead plant and animal remains including faecal matter into smaller particles.
Short Answer Type Questions – l
Question. Write about ‘humification’ and the ‘mineralisation’ occurring during the process of decomposition.
Answer : Humification leads to break down of complex organic matter and accumulation of humus in the form of a dark amorphous substance in soil.
Mineralisation is a process in which humus is degraded by microbes to release inorganic nutrients.
Question. Explain primary productivity and the factors that influence it.
Answer : Primary productivity is the amount of biomass produced per unit area over a time period by green plants during photosynthesis. The factors that influence it are the plant species of the area, their photosynthetic activity, availability of nutrients, solar radiations, precipitation, soil types and the various environmental factors.
Question. How does the dead organic matter get decomposed in nature ? Explain.
Answer : In nature, the dead organic matter gets decomposed by the micro-organisms like bacteria and fungi. These microorganisms called decomposers break down the complex organic matter into simpler inorganic substances like CO2, water and nutrients.
Question. What does secondary productivity in an ecosystem indicate ? List any two factors by which productivity is limited in an aquatic ecosystem.
Answer : Secondary productivity indicates the organic matter synthesized by the consumers specially by the primary consumers or herbivores. The two factors by which the productivity is limited in an aquatic ecosystem are light and nutrient supply.
Question. How are productivity, gross productivity, net primary productivity and secondary productivity interrelated ?
Answer : NPP = GPP – R Productivity is the rate of production of biomass at any trophic level at any given interval of time.
Gross productivity : It is the rate of production of organic matter by green plants per unit time per unit area. On the other hand we can say that it is the total amount of productivity.
Net Primary Productivity : It is the difference between gross primary productivity and the loss due to respiration.
Secondary Productivity : It is rate of production or formation of new organic matter by consumers especially the consumers of the first order or herbivores.
Short Answer Type Questions – ll
Question. Describe how oxygen and chemical composition of detritus control decomposition ?
Answer : Decomposition of detritus is an oxygen requiring process i.e. it takes place under aerobic condition in the presence of oxygen. Chemical composition of detritus affects decomposition. Detritus which is rich in nitrogen and water soluble substances decomposes rapidly whereas the detritus having chitin and lignin decomposes at a very slow rate.
Question. Why is earthworm considered a farmer’s friend?
Explain humification and mineralisation occurring in decomposition cycle.
Answer : Earthworms are called farmer’s friends because they bring about the fragmentation of detritus and loosening of soil.
Humification is the process of formation of humus from detritus. Mineralization is the process of release of inorganic substances as both non-mineral and minerals from organic matter.
Question. (i) What is primary productivity ? Why does it vary in different types of ecosystems ?
(ii) State the relation between gross and net primary productivity.
Answer : (i) Primary productivity : Production of biomass / produced energy per unit area in a certain time period (per year) by plants during photosynthesis. It depends upon – plant species inhabiting a particular area, environmental factors, availability of nutrients, photosynthetic capacity of plants.
(ii) GPP – R = NPP
NPP = Net Primary Productivity
GPP = Gross Primary Productivity
R = Respiration Losses
Long Answer Type Questions
Question. Describe the process of decomposition of detritus under the following headings: Fragmentation; leaching; catabolism; humification and mineralisation.
Explain the different steps involved in the process of decomposition of detritus.
Answer : The process of breaking down complex organic matter into inorganic substances like—CO2, water and nutrient is called decomposition. The raw materials for decomposition is called detritus.
They are dead remains of plants and animals.
Steps of decomposition :
Fragmentation : Breakdown of detritus into smaller particles e.g. earthworm.
Leaching : Water soluble inorganic nutrients go down into the soil horizon and get precipitated as unavailable salts.
Catabolism : Bacterial and fungal enzymes degrade detritus into simpler inorganic substances.
Humification : It leads to the accumulation of a dark coloured amorphous substance called humus that is highly resistant to microbial action and undergoes decomposition at an extremely slow rate.
Mineralisation : The humus is further degraded by some microbes and release inorganic substances by this process.
Question. Citing lake as an example of a simple aquatic ecosystem, interpret how various functions of this ecosystem are carried out. Make a food chain that is functional in this ecosystem.
Answer : The components of lake ecosystem (viz : abiotic components, biotic components, consumers of various order and decomposers) function as an unit for various function of ecosystem as follows—
(i) Productivity—conversion of inorganic into organic material with the help of solar energy by the autotrophs.
(ii) Energy flow—unidirectional movement of energy towards higher trophic level
(and its dissipation and loss as heat to the environment).
(iii) Decomposition—fragmentation, leaching, catabolism, humification, mineralization by bacteria, fungi and flagellates (abundant at the bottom of lake).
(iv) Nutrient cycling—decomposition of dead matter to release the nutrients back to be reused by the autotrophs.
Food chain in aquatic ecosystem (lake):
Phytoplanktons ⇒ Zooplanktons ⇒ Small
fish ⇒ Big fish.
Question. Taking a small pond as an example of an ecosystem, list the four components of this ecosystem. How do these components function as a unit in a small pond ?
Answer : Four components of small pond ecosystem are: Abiotic components – air, water, soil, light, temperature, other climatic conditions.
Biotic components – producers-phytoplanktons, some algae, floating and submerged plants.
Consumers of various order – Zooplanktons
Decomposers – Fungi, bacteria and other flagellates.
(any four-1 mark; any two-1/2 mark; atleast one biotic and abiotic components should be mentioned) Components work as a unit for the following functions :
Productivity : Conversion of inorganic into organic material through photosynthesis with the help of solar energy and consumption of autotrophs by heterotrophs i.e. secondary productivity.
Decomposition : Decomposition and mineralisation of the dead matter.
Nutrient Cycling : To release the nutrients / elements back for use by autotrophs.
Energy Flow : Unidirectional flow of energy and its subsequent dissipation as one moves towards higher trophic levels.
Question. (i) Explain primary productivity and the factors that influence it.
(ii) Describe how oxygen and chemical composition of detritus control decomposition.
Answer : (i) Primary productivity : Amount of biomass / organic matter produced per unit area over a time period by the plant during photosynthesis.
Factors : availability of nutrients / quality of light available / availability of water / temperature of the given place / type of plant species of the area / photosynthetic capacity of the plants.
(ii) Oxygen increases rate of decomposition. Decomposition is an oxygen consuming process. It takes place under aerobic conditions i.e. in presence of oxygen.
Chemical decomposition is slow when chitin and lignin are present and fast when cellulose and water soluble substances are present.
Question. (i) Taking an example of a small pond, explain how the four components of an ecosystem function as a unit.
(ii) Name the type of food chain that exists in a pond.
Answer : (i) Productivity : Conversion of inorganic substances into organic material with the help of radiant energy / sunlight by the autotrophs / producers (phytoplankton, algae, floating, submerged plants).
Decomposition : Decomposers (fungi, bacteria, flagellates) breakdown dead decayed organic matter into simpler compounds.
Energy flow : Unidirectional movement of energy towards higher trophic levels (producer to consumer) and its dissipation and loss as heat to the environment.
Nutrient cycle : Mineralisation of dead matter to release them back for reuse of autotrophs.
(ii) Grazing food chain / detritus food chain.
Energy Flow and Ecological Succession
Very Short Answer Type Questions
Question. What is detritus food chain made up of ? How do they meet their energy and nutritional requirements ?
Answer : Detritus food chain is made up of decomposer organisms, which are mainly the microorganisms like bacteria and fungi. They meet their energy and nutritional requirements by degrading dead organic matter or detritus.
Question. Define Standing Crop.
Answer : Each trophic level has a certain mass of living material at a particular time called as the standing crop.
Question. ‘It is possible that a species may occupy more than one trophic level in the same ecosystem at the same time.’ Explain with the help of one example.
Answer : Yes, it is possible because the trophic level of a species represents the functional role of the organism in energy flow, which is determined by the food it takes. For example, sparrow is an omnivore. When it eats seeds, fruits or any other plant product, it occupies the primary trophic level. whereas, when it eats worms and any other insects, t occupies the secondary trophic level. Thus, it occupies more than one trophic level in the same ecosystem.
Question. ‘Man is a primary as well as the secondary consumer’. Justify this statement.
Answer : The man is a primary consumer when he eats plants or their products and is a secondary consumer when he eats animals. Man is in fact omnivore because he eats both plants as well as animals.
Question. What is the starting point of a detritus food chain.
Answer : Detritus food chain (DFC) start from detritus or dead and decaying organic matter i.e. dead plants and animals waste and animal faeces. Detrivores and decomposers feed over it.
Question. State what does ‘standing crop’ of a trophic level represent.
Answer : It is the total amount of living matter or organic matter present in an ecosystem in a unit area and unit time. It is measured as the mass of living organisms i.e. biomass or their number in unit area.
The biomass of a species is expressed in terms of dry or fresh weight.
Question. Mr. Galgotia eats curd/yoghurt. In this case, which trophic level will he occupy ?
Answer : He would occupy third trophic level in this case.
Identify the type of the given ecological pyramid and give one example each of pyramid of number and pyramid of biomass in such cases.
Answer : Inverted pyramid
Inverted pyramid of biomass in a lake –
Phytoplankton → Zooplankton → Fishes.
Inverted pyramid of number – tree → insects → Birds.
Question. Write the basis on which an organism occupies a space in its community/natural surroundings.
Answer : Feeding relationship with other organisms.
Short Answer Type Questions – l
Question. Why is it difficult to get rid of ‘water hyacinth’ from a water body ? Name one abiotic component and one biotic component of the ecosystem that get affected by its spread in the water body.
Answer : Water hyacinth have caused havoc by their excessive growth. They grow abundantly in eutrophic water bodies and lead to an imbalance in the ecosystem dynamics of the water body.
Abiotic component : Water hyacinth impacts water flow and blocks oxygen.
Biotic component : This plant blocks sunlight from reaching native aquatic plants and poses threats to them.
Question. List the features that make a stable biological community.
Answer : Following features make the biological community stable :
(i) The community is an equilibrium with the biotic and abiotic factors.
(ii) In a community there is a large number of small and larger sized organisms.
(iii) The organisms in a stable community have longer life span.
Question. Why is the pyramid of energy always upright? Explain.
It is stated that the pyramid of energy is always upright. Justify.
Answer : The pyramid of energy is always upright because there is a gradual decrease in the energy contents in successive trophic levels from producers to consumers of various order. According to Lindeman’s 10% law, only 10% of the total energy is available to the next higher trophic level.
Question. Why are herbivores considered similar to predators in ecological context ? Explain.
Answer : The herbivores are considered like predators in ecological context because they feed on plants for their enery and nutritionl requirements just as the predators feed on their prey for their food requirement.
Question. State the difference between the first trophic levels of detritus food chain and grazing food chain.
Answer : In detritus food chain, the detrivores and decomposers constitute the first trophic level whereas in grazing food chain the producers i.e. the autotrophic green and photosynthetic plants constitute the first trophic level.
Short Answer Type Questions – ll
Question. In a botanical garden of a city there is a huge banyan tree growing on which hundreds of birds and thousands of insects live. Draw the pyramids of numbers and also biomass represented by this community. Comment giving reasons on the two different pyramids drawn.
Answer : Pyramid of Numbers – Inverted, number is increasing as one moves from producers to secondary consumers.
(Shape, labeling, reason)
Pyramids of Biomass – upright – a huge tree with maximum biomass supports several birds with lesser biomass and insects with even lesser biomass.
(Shape, labeling, reason)
Question. Differentiate between primary and secondary succession. Provide one example of each.
Question. What is ecological succession ? Where and why would the rate of succession be faster in newly created pond or a forest destroyed by a forest fire?
Answer : Gradual / predictable change in the species composition of given area. Rate of succession would be faster in a forest destroyed by a forest fire. Such disturbances create new conditions that encourage some species and discourage or eliminate other species / since after a forest fire some soil is already present, so, succession is faster than primary succession.
Question. “In a food-chain, a trophic level represents a functional level, not a species.” Explain.
Answer : Position of a species in any trophic level is determined by the function performed by that mode of nutrition of species in a particular food chain / A given species may occupy more than one trophic level in the same ecosystem (in different food chains) at the given time. If the function of the mode of nutrition of species changes its position shall change in the trophic levels, same species can be at primary consumer level in one food chain and at secondary consumer level in another food chain in the same ecosystem at the given time.
Similar value points explained with the help of a suitable example.
Question. How does a detritivore differ from a decomposer ?
Explain each with an example.
Question. Explain successions of plants in xerophytic habitat until it reaches climax community.
Answer : Lichens on bare rock, secrete acids to dissolve rock (weathering of soil), Bryophytes to hold soil, water, grass, small plants/shrubs, tree-forest (Climax community).
Question. Construct labelled grazing and detritus food chains with minimum three trophic levels each.
Answer : Grazing food chain :
Autotrophs → Herbivores → Primary carnivores → secondary carnivores.
Detritus food chain :
Decay and → decomposer → soil animal
excretory organism which consume
materials other soil
from the organisms.
grazing food chain.
Question. Match the column A with any two of the two column B.
Question. Name the pioneer species on a bare rock. How do they help in establishing the next type of vegetation ? Mention the type of climax community that will ultimately get established.
Answer : The pioneer species on a bare rock are usually lichen, mosses and annual grass stage and bluegreen algae. In primary succession on rocks, lichens are able to secrete acids to dissolve rocks, helping in weathering and soil formation. It paves way to some very small plants like bryophytes, which are able to take hold in the small amount of soil. They are with time, succeeded by bigger plants.
Several hard and light demanding trees grow in the area occupied by shrubs. Slowly environment becomes more moist and shadier so that plants of climax community can spread in this area. The type of climax community that will ultimately get established are shrubs and trees.
Long Answer Type Questions
Question. (i) Colonization of a rocky terrain is a natural process. Mention the group of organisms which invade this area first. Give an example.
(ii) Over the years, it has been observed that some of the lakes are disappearing due to urbanization. In absence of human interference, depict by making a flow chart, how do the successional series progress from hydric to mesic condition.
(iii) Identify the climax community of hydrarch and xerarch succession.
Answer : (i) Pioneer species, lichen
Submerged plant stage
Submerged free floating plant stage
Reed swamp stage
Question. (i) Construct a pyramid of numbers considering a big banyan tree supporting a population of insects, small birds and their predators.
(ii) Differentiate, giving reason, between the pyramid of biomass of the above situation and the pyramid of numbers that you have drawn.
This is a spindle-shaped Pyramid.
In the above pyramid, the population of insects is more than the tree, therefore, the size of pyramid increases, but the number of small birds is lesser than the insects. The pyramid size becomes narrow.
Further, big birds are lesser than small birds. So the size of pyramid becomes narrower.
(ii) Actually, the pyramids of numbers do not give a true picture of the food chain, as they are not very functional. They do not indicate the relative effect of the geometric food chain and size. Here, the size of the pyramid becomes variable.
The pyramid of biomass of the given situation will be :
The pyramid of biomass in this ecosystem is upright because the biomass decreases at each trophic level.
Question. Explain how xerarch succession progresses from xeric to mesic condition and forms a stable climax community. You may use a flow chart.
Answer : Xerarch succession : Xerarch succession takes place in dry areas and the series progress from xeric to mesic condition.
In primary succession on rocks, the pioneer species
i.e. lichens secrete acids to dissolve rock, helping
in weathering and soil formation. These later pave way to some very small plants like bryophytes which are able to take hold in the small amount of soil. They are with time, succeeded by bigger plants and after several more stages ultimately a stable climax forest community is formed.
The climax community remains stable as long as the environment remains unchanged. With time the xerophytic habitat gets converted into a mesophytic one.
The stages in xerarch succession are as follows :
Lichens (Pioneer community)
Bryophytes (mosses) (Serial communities)
Trees (Climax community)
In secondary succession, the species that invade depends on the condition of the soil, availability of water, the environment and also on the seeds or other propagules present. Since soil is already there, the rate of succession is much faster and hence, climax is also reached more quickly. Primary succession is a slow process, taking about thousands of years for the climax to be reached. Another important fact is to understand that all succession, whether taking place in water or on land, proceed to a similar climax community, the mesic.
Question. (i) Draw an ideal pyramid of energy upto four trophic levels where 10,000 J are available from sunlight to the primary producer. Indicate the amount of end product available at each trophic level.
(ii) Why is pyramid of energy always upright? Explain.
(iii) Mention the limitations of an ecological pyramid.
Answer : (i) (a) Please note: In fig. 14.4 the energy from sunlight mentioned is 1000,000 J. However, in question it is 10,000 J. Hence, there will be change in the energy transferred at different tropic levels. Energy Levels will start from100,
10 and 1
(b) Figure 14.4 shows an ideal pyramid of energy.
Observe that primary producers convert only 1% of the energy in the sunlight available to them into NPP.
(ii) Pyramid of energy is always upright, can never be inverted, because when energy flows from a particular trophic level to the next tropic level, some energy is always lost as heat at each step. Each bar in the energy pyramid indicates the amount of energy present at each trophic level in a given time or annually per unit area.
(iii) There are certain limitations of ecological pyramids such as :
(a) It does not take into account the same species belonging to two or more trophic levels.
(b) It assumes a simple food chain, something that almost never exists in nature.
(c) It does not accommodate a food web.
(d) Moreover, saprophytes are not given any place in ecological pyramids even though they play a vital role in the ecosystem.
Question. (i) Comment on the pattern in which all communities undergo a change in composition and structure with changing environmental conditions.
(ii) Explain ‘Climax community‘ and ‘sere‘.
(iii) Differentiate between primary and secondary succession with examples.
Answer : (i) Orderly and sequential changes, parallel with changes in physical environment
(ii) Climax community – changes finally, lead to a community that is in equilibrium with environment.
Sere – the entire sequence of communities that successively change in a given area.
(iii) Primary succession
(i) Occurs in newly cooled lava / bare rock / newly created pond.
(ii) Slow process. Secondary succession
(i) Occurs in abandoned / destroyed forest.
(ii) Fast process.
Question. (a) What is a trophic level in a ecosystem ? What is ‘standing crop’ with reference to it ?
(b) Explain the role of the ‘first trophic level’ in an ecosystem.
(c) How is the detritus food chain connected with the grazing food chain in a natural ecosystem ?
Answer : (a) Specific place of an organism in a food chain, mass of living material (biomass) at each trophic level at a particular time.
(b) First trophic level has producers / autotrophs, which trap solar energy / to produce food
(c) Organisms of the Detritus food chain (DFC) are the prey to the Grazing food chain (GFC) organism, the dead remains of GFC are decomposed into simple inorganic materials which are absorbed by DFC organisms.
Nutrient Cycling and Ecosystem Services
Very Short Answer Type Questions
Question. Explain the functions of reservoirs in a nutrient cycle. List two types of nutrient cycles in nature.
Answer : The two types of nutrient cycles are gaseous and sedimentary. Atmosphere is the reservoir for gaseous cycle and lithosphere is the reservoir of sedimentary cycle respectively. The reservoir is required to meet the deficiency of nutrients due to the imbalance in rate of influx and efflux.
Question. Name the two type of nutrient cycles existing in nature. Where are their reservoirs present ? State the functions of the reservoirs.
Answer : The nutrients are never lost from an ecosystem but are recycled time to time and again indefinitely.
Nutrient cycles are of two types :
(i) Gaseous cycles : The reservoir for gaseous cycles exists in the atmosphere e.g. carbon cycle, nitrogen cycle.
(ii) Sedimentary cycles : The reservoir for sedimentary cycles exists in the earth’s crust e.g phosphorus cycle, sulphur cycle.
The function of the reservoir is to meet with the deficit, which occurs due to imbalance in the rate of influx and efflux.
Question. Global carbon is fixed in the biosphere through photosynthesis. Explain any two ways by which carbon is returned to the atmosphere.
Answer : The carbon is returned to the atmosphere through respiration by all living beings and burning fossil fuel. Considerable amount of carbon returns to the atmosphere as CO2 through respiratory activities of the producers and consumers. Decomposers also contribute substantially to CO2 pool by their processing of waste materials and dead organic matter of land or oceans.
Burning of wood, forest fire and combustion of organic matter, fossil fuel, volcanic activity are additional sources for releasing CO2 in the atmosphere.
Rapid deforestation and massive burning of fossil fuel for energy and transport have significantly increased the rate of release of carbon dioxide into the atmosphere.
Short Answer Type Questions – l
(i) (a) Name the biogeochemical (nutrient) cycle shown above.
(b) Name an activity of the living organisms not depicted in the cycle by which this nutrient is returned to the atmosphere.
(ii) How would the flow of the nutrient in the cycle be affected due to large scale deforestation ? Explain giving reasons.
(iii) Describe the effect of an increased level of this nutrient in the atmosphere on our environment.
Answer : (i) (a) Carbon cycle in biosphere.
(b) Volcanic activity and mining, microbial decomposition of organic matter.
(ii) Clearing of vast areas covered by forest, by man, is called deforestation. It is the main cause of soil erosion in India. Due to large scale deforestation, the flow of carbon in the environment will be disturbed because the evironment will be disturbed because carbon for photosynthesis. This would lead to accumulation of carbon in the atmosphere.
(iii) Increase in the level of carbon in atmosphere will result in greenhouse effect. This will lead to heating of earth’s surface and finally to global warming. Rise in temperature, results in odd climatic changes, which are harmful for the environment.
Question. (i) Healthy ecosystems are the base of wide range of (ecosystem) services. Justify.
(ii) Explain the difference and the similarities between hydrarch and xerarch successions of plants
Answer : (i) Healthy ecosystems are the base for a wide range of economic, environmental and aesthetic goods and services. The products of ecosystem processes are named as ecosystem services. For examples, healthy forest ecosystem purifies air and water, minimize droughts and floods, cycle nutrients, generates fertile soils, provides wildlife habitat, maintains biodiversity, pollinate crops, provide storage site for carbon and also provide aesthetic, cultural and spiritual values. Though value of such services of biodiversity is difficult to determine, it seems reasonable to think that biodiversity should carry a healthy price tag.
(ii) Based on the nature of the habitat – whether it is water (or very wet areas) or it is on very dry areas – succession of plants is called hydrarch or xerarch, respectively.
Differences : Hydrarch succession takes place in wetter areas and the successional series progress from hydric to mesic conditions. As against this, xerarch succession takes place in dry areas and the series progress from xeric to mesic conditions.
Similarity : Both hydrarch and xerarch successions lead to medium water conditions (mesic), neither too dry (xeric) nor too wet (hydric).
Long Answer Type Questions
Question. Discuss the role of healthy ecosystem services as a pre-requisite for a wide range of economic, environmental and aesthetic goods and services.
Describe the advantages of keeping the ecosystems healthy.
Answer : The various advantages of keeping the ecosystem healthy are as follows :
(i) Healthy ecosystem is the base for a wide range of economic, environmental and aesthetic goods and services.
(ii) The products of ecosystem processes are named as ecosystem services, as they are of great help to the organisms living within an ecosystem.
(iii) Healthy forest ecosystem purify air and water.
(iv) It also mitigates droughts, floods and cycle nutrients.
(v) Healthy ecosystem generates fertile soil and provides wildlife habitat.
(vi) Maintenance of biodiversity is also an important aspect of healthy ecosystem.
(vii) It also provides aesthetic, cultural and spiritual values.