• The ecosystem services include 
• provisioning services such as food and water;
• regulating services such as regulation of floods, drought, land degradation, and disease; 
• supporting services such as soil formation and nutrient cycling;
• and cultural services such as recreational, spiritual, religious and other non-material benefits.
  

Ecologists believe that the communities with more species tend to be more stable than those with less species.

Keystone species are those species which have significant and disproportionately large influence on the community structure and characteristic. It has often considered low abundance and biomass as compared to dominant species.

According to the mechanism of resource partitioning (supported by Mac Arthur), if two species compete for the same resource, they could avoid competition by choosing, for instance, different times for feeding or different foraging patterns. Two species evolve to become different too reduce competition, so that species can co-exist. 

The correct answer is 'all of the above'

Detritus is defined as dead and decaying organic matter that includes fallen leaves, dead plant parts and animals. It is the primary source of energy in the detritus food chain in which the microbes such as protozoans, bacteria and fungi help in the breaking down of the complex organic matter. They are called decomposers. Detritus food chain hence helps in soil replenishment by adding nutrients to the soil. They convert organic matter into carbon dioxide and nutrients. Thus the correct answer is option B.

Any ecosystem has two components -biotic or living organisms and abiotic or non-living component. 

• The carbon cycle is the series of processes by which carbon compounds are interconverted in the environment, involving the incorporation of carbon dioxide into living tissue by photosynthesis and its return to the atmosphere through respiration, the decay of dead organisms, and the burning of fossil fuels.
• Carbon is the main component of biological compounds as well as a major component of many minerals such as limestone.
  

The plants can fix carbon dioxide from the atmosphere which is taken in through stomata. The carbon dioxide is converted in the presence of light and chlorophyll pigments to synthesize carbon containing organic compounds such as sugar, fats and proteins. This creates the plant biomass which when eaten by other organisms recycles the carbon from on level to other. Finally the carbon enters the geosphere and then the atmosphere. The oxygen which is formed during photosynthesis is liberated in the atmosphere and used for cellular respiration. The oxygen is used to break down the molecules and release the carbon dioxide. The carbon gets recycled in the environment from plants to animals and then again enters the environment. 

Answer is option A i.e. "Low stability and high resilience"
Stability is the power of a system to be in their state against unfavorable factor. Resilience is the capability of regaining its original shape or position after being deformed. An ecosystem which can be easily damaged but can recover after sometime when it 's damaging effect stops will be having low stability and high resilience. Hence, it has low stability and high resilience.

During summer the land becomes dry and rainfall induces formation of grass and hence heavy rainfall during summer produces grasslands.

Plants take nitrogen from the soil by absorption through their roots as nitrate ions and ammonium ions.Nitrite is intermediate and gets converted to either forms by symbiotic or non-symbiotic bacteria present in plant roots and soil respectively.  Most nitrogen obtained by terrestrial animals can be traced back to the eating of plants at some stage of the food chain.

Salvia, Morus, Euphorbia are pollinated by insects (entomophily)

Carbonization (or carbonisation) is the term for the conversion of an organic substance into carbon or a  carbon containing residue through destructive distillation or pyrolysis (also occurs in nature). It is often used in organic chemistry with  reference to the generation of coal gas and coal tar from raw coal.

Phanerogamae are the sub-kingdom of kingdom Plantae. They include seed bearing and flowering plants. They are further grouped into angiosperms and gymnosperms. Gymnospermic plants are pollinated by wind that is anemophilous.

Cross pollination is the transfer of pollen from the anthers of a flower of one plant to the stigma of a flower of another  plant. It is a natural process.

It is wrong that the forest do not conserve soil. Actually forest prevent soil erosion by covering the soil by the canopy of the plants and reduces the impact of rain water and wind on the top layer of soil. The roots hold the soil and also prevent soil erosion.

The functional aspects of an ecosystem include the regulation of populations, flow of energy, biogeochemical cycles, and the flow of nutrients. It also includes ecological succession, food chain, ecological pyramid, food web. Populations are regulated in an ecosystem through these food chains.

Ecosystem is made up of living and nonliving things. Living things include plants and animals. Nonliving things includes air, water, land.  It is composed of organisms interacting within communities. The importance of ecosystem lies in both cycling of minerals and flow of energy. It does not alter normally because it is in a state of homeostasis. There is always balance of organisms in an ecosystem within themselves and with changing environment.

An ecosystem is made up of living and nonliving things. Living things include plants, animals. Nonliving things include air, water. It creates food chains and food web. A food chain is series of plants/animals which are interrelated in the form of organism being eaten as food by the other. plants are producers. The animals eating plants are called as primary consumers and animals eating primary consumers are called as secondary consumers. Decomposers are those which decomposes the waster organic matter. Food web is various interlinked food chains in a community.

Ecosystem is made up of living and nonliving things. Living things include plants and animals. Nonliving things includes air, water, land.  It is composed of organisms interacting within communities. The importance of ecosystem lies in both cycling of minerals and flow of energy. It contributes to the cycling of minerals and flow of energy.

Robert Constanza gave price tags to ecosystem services. According to him, soil formation accounts for 50% of the ecosystem service. It is the most important ecosystem service. The other ecosystem services include purify water and air, mitigate droughts and floods, nutrient cycling, habitat for wild life.

The benefits which we obtain from the regulation of ecosystem processes such as climate regulation, natural hazard regulation, water purification, and waste management, pollination or pest control are known as Ecosystem services. Agroecosystems, forest ecosystems, grassland ecosystems, and aquatic ecosystems are included under these ecosystems. These are also known as regulating services. Examples include Climate regulation, Waste treatment, and disease regulation. 

• Trees control atmospheric carbon dioxide concentration because they take up carbon dioxide and perform photosynthesis through which they release oxygen in the atmosphere. Hence, quality of air is maintained by ecosystems.
• The roots of plants held the soil particles tightly which prevent soil erosion.
• Plants filter out pollutants from water and air by trapping pollutants. They absorb pollutants from air and water in their tissues. 

The aquatic ecosystem is the interaction of biotic component and abiotic component in the water body. It serves important environmental services such as recycling of nutrients, water purification, attenuate floods, recharge groundwater and provides shelter to wildlife. Aquatic ecosystems are also used for human recreation, and are very important to the tourism industry, especially in coastal regions. 

Insect-pollinated flowers are large, have brightly coloured petals, often sweetly scented, usually contain nectar- to attract insects. Its pollen are often sticky or spiky - to stick to legs and body of  insects

Deep lakes at mid-latitudes have well-pronounced stratification which leads to the lakes experiencing wealthy internal waves dynamics. These lakes also possess seasonal water mixing during the spring and autumn transitional periods. This is due to the non-linear thermal expansion of water when its temperature reaches 4$^0$C and the density of water is maximum.  Further, with the increasing latitudes support the general cyclonic water circulation. Hence the large lakes along mid-latitudes show a large variety of these physical processes.

A Freshwater ecosystem is one of  the aquatic ecosystems of the earth and includes lakes, ponds, rivers, streams and wetlands. This ecosystem is essential as it not only provides human beings their drinking water, but these are also home to more than 40 percent of the world's fish species. The seasonal changes occur in the freshwater ecosystem with regards to temperature-density relationship and since it contains continuous running water so materials are recycled more quickly than in ocean ecosystems.

Robert Constanga et al have tried to put price tags on natures life support services. He gave price tags to the ecosystem services. Out of these services, 50% accounts for the soil formation. The ecosystem services he put price on includes purify water and air, mitigate droughts and floods, nutrient cycling, habitat for wild life.