• Reasons for the reduction of soil organic carbon:
• There may be natural factors such as floods, earthquakes and volcanoes.

• The human induced factors are:

• Urban expansion Over grazing Excessive tillage
• Land degradation due to inappropriate agriculture practices
• Frequent cropping
• Unscientific crop rotation
• Improper agriculture practices
• Poor irrigation and water management

• A seral stage is an intermediate stage found in ecological succession in an ecosystem advancing towards its climax community.
• In many cases more than one seral stage evolves until climax conditions are attained.

• As Earth’s climate warms, the permafrost is thawing.
• That means the ice inside the permafrost melts, leaving behind water and soil.
• Thawing permafrost can have dramatic impacts on our planet and the things living on it.
• For example: Many northern villages are built on permafrost.
• When permafrost is frozen, it’s harder than concrete.
• However, thawing permafrost can destroy houses, roads and other infrastructure.
• When permafrost is frozen, plant material in the soil—called organic carbon—can’t decompose, or rot away.
• As permafrost thaws, microbes begin decomposing this material.
• This process releases greenhouse gases like carbon dioxide and methane to the atmosphere.
• When permafrost thaws, so do ancient bacteria and viruses in the ice and soil.
• These newly-unfrozen microbes could make humans and animals very sick.
• Scientists have discovered microbes more than 400,000 years old in thawed permafrost.

• Eutrophication is when a body of water becomes overly enriched with minerals and nutrients which induce excessive growth of algae.
• This process may result in oxygen depletion of the water body.
• One example is an “algal bloom” or great increase of phytoplankton in a water body as a response to increased levels of nutrients.
• Eutrophication is often induced by the discharge of nitrate or phosphate-containing detergents, fertilizers, or sewage into an aquatic system.

• The Wild Life Protection Act, 1972 is an Act of the Parliament of India enacted for protection of plants and animal species.
• The Act established schedules of protected plant and animal species.
• It has six schedules which give varying degrees of protection.
• Schedule I and part II of Schedule II provide absolute protection – offences under these are prescribed the highest penalties.
• Species listed in Schedule III and Schedule IV are also protected, but the penalties are much lower.
• Schedule V includes the animals which may be hunted à They are known as Vermins.
• Schedule VI is exclusive for Plants.
• The specified endemic plants in Schedule VI are prohibited from cultivation and planting.

• Mangrove environment is highly dynamic and harsh and mangrove species are variously adapted to cope with these environmental conditions.

• Breathing roots: Underground tissue of any plant requires oxygen for respiration and in mangrove environment, oxygen in soil is very limited or nil.
• This necessitates mangrove root system to take up oxygen from the atmosphere.
• For this purpose, mangrove species have specialized above ground roots called breathing roots or pneumatophores.
• These roots have numerous pores through which oxygen enters into the underground tissues.
• In some plants buttress roots function as breathing roots and also provide mechanical support to the tree.

• Silt roots: In some mangrove species, roots diverge from stems and branches and penetrate the soil some distance away from the main stem as in the case of banyan trees.
• Because of their appearance and because they provide the main physical support to these they are called as stilt roots.
• These roots also have many pores through which atmospheric oxygen enters into the roots.

• Vivipary: Saline water, unconsolidated saline soil with little or no oxygen is not a conducive environment for seeds to germinate and establish.
• To overcome this, mangrove species have unique way of reproduction, which is generally known as vivipary.
• In this method of reproduction, seeds germinate and develop into seedlings while the seeds are still attached to the parent tree.
• These seedlings are normally called as propagules and they photosynthesize while still attached to the mother tree.
• The parent tree supplies water and necessary nutrients.
• They are buoyant and float in the water for some time before rooting themselves on suitable soil.

• Increasing anthropogenic activities along with natural stresses have led to massive degradation of one of India’s World Heritage Site — the Sunderbans. Nutrient depletion especially phosphorus and nitrogen was found to be directly connected with the decline in forest cover.

There was a change in the species distribution — salt-sensitive ones such as Heriteira fomes, Xylocarpus species and Phoenix paludosa were not able to cope up with the increase in the salinity and declined while the tolerant varieties thrived.

• The 1995 Basel Ban Amendment, a global waste dumping prohibition, has become an international law after Croatia ratified it on September 6, 2019.
• Croatia became the 97th country to ratify the ban, which was adopted by the parties to the Basel Convention in 1995, to protect human health and the environment against the adverse effects of hazardous wastes, according to Basel Action Network (BAN).
• BAN is a Unites States-based charity organisation and is one among the organisations and countries, which created the Basel Ban Amendment — hailed as a landmark agreement for global environmental justice.
• The Ban Amendment prohibits all export of hazardous wastes, including electronic wastes and obsolete ships from 29 wealthiest countries of the Organization of Economic Cooperation and Development (OECD) to non-OECD countries.

• “Although often harmful and destructive to humans, naturally occurring wildfires play an integral role in nature.
• They return nutrients to the soil by burning dead or decaying matter.
• They also act as a disinfectant, removing disease-ridden plants and harmful insects from a forest ecosystem.
• And by burning through thick canopies and brushy undergrowth, wildfires allow sunlight to reach the forest floor, enabling a new generation of seedlings to grow.”

• An ice sheet is a mass of glacial land ice extending more than 50,000 square kilometers (20,000 square miles).
• The two ice sheets on Earth today cover most of Greenland and Antarctica.
• During the last ice age, ice sheets also covered much of North America and Scandinavia.
• Ice sheets contain enormous quantities of frozen water.
• Together, the Greenland and Antarctic Ice Sheets contain more than 99 percent of the freshwater ice on Earth.
• Ice sheets form in areas where snow that falls in winter does not melt entirely over the summer.
• Over thousands of years, the layers of snow pile up into thick masses of ice, growing thicker and denser as the weight of new snow and ice layers compresses the older layers.
• Ice sheets are constantly in motion, slowly flowing downhill under their own weight.
• The Greenland and Antarctic ice sheets also influence weather and climate.
• The mass of ice in the Greenland Ice Sheet has begun to decline.