Forest and Grassland Ecosystems

Forest Ecosystem Case Study

• Focuses on forest and grassland ecosystems, deforestation, and the impacts of mining and dam construction on the environment, forests, biodiversity, and tribal populations.
• An ecosystem encompasses all organisms in a specific area that interact with the physical environment.
• Energy flow within an ecosystem leads to well-defined trophic structures, biotic diversity, and material cycles, which involve the exchange of materials between living and non-living elements.

Forest Ecosystems

• Terrestrial ecosystems characterized by different types
• Depend on temperature and ground moisture for tree growth
• Include complex biotic communities, each with specific flora and fauna.
• Are extensive land areas with complex assemblages of microbial, fungal, plant, and animal populations.
• Are conditioned by ecological factors like high insolation, ample rainfall, high moisture, humidity, and optimum temperatures.
• Cover 20% of the Earth's land surface, which is about 30,000,000 sq. km.
• Are found in both tropical and temperate regions.
• Maintain a sound ecological equilibrium and have high humidity due to extensive transpiration.
• There is high and stable moisture content in the soil, and limited water loss below the canopy layer.
• Daytime is generally cooler and nighttime is warmer than surrounding areas.
• Summer temperatures are lower and winter temperatures are higher

Forest Ecosystem Components

• Forest ecosystems are natural habitats for plants and animals in woodland areas.
• They include all living (biotic) and non-living (abiotic) components interacting with each other.
• The biotic components are divided into producers, consumers, and decomposers.
• Abiotic components include inorganic and organic substances present in the soil and atmosphere, and trace elements in the soil.

Biotic Components/ Producers

• Formed mainly of trees exhibiting high species diversity.
• Tree species vary based on the type of forest formation.
• Include trees, shrubs, and ground vegetation.
• The main producers are flora, with other examples being Tectona grandis and Butea frondosa.
• In temperate deciduous forests, common producers include Acer, Betula, and picea species.

Biotic Components/ Consumers

• Include all animals, including mammals and others.
• Consumers rely on plants and other animals for food.
• Primary consumers only eat plants and are referred to as herbivores; ants, beetles, leaf hoppers, and spiders
• Secondary consumers eat herbivores and are referred to as carnivores
• Tertiary consumers obtain nutrition by eating primary and secondary consumers, such as lions and tigers.
• Omnivores eat both plants and animals.

Biotic Components/ Decomposers

• Are organisms that live off of ingesting dead organisms.
• Decomposers break down dead plants and animals, returning the nutrients to the soil.
• Include bacteria such as Bacillus and Clostridium, fungi such as Aspergillus, polyporus, and Trichoderma, actinomycetes, ants, termites, and earthworms.
• Decomposition occurs more rapidly in tropical and subtropical forests.

Forest Types

• Tropical rain forests are evergreen broadleaf forests near the equator.
• They have high temperatures, high humidity, uniform climates, and high species diversity.
• Tropical deciduous forests away from the equator have warm climates throughout the year with monsoon rains and leaf shedding during the dry season.
• Tropical scrub forests are in areas with long dry seasons and small deciduous trees.
• Temperate rain forests have adequate rainfall and are dominated by coniferous trees like pines and firs.
• Temperate deciduous forests have moderate temperatures, marked seasonality, long summers, cold but not severe winters with abundant rainfall, and include broadleaf trees like oaks, hickory, and poplars.
• Evergreen coniferous/Boreal forests are found south of the arctic tundra.
• They endure long, cold, dry winters and short, mild summers with needle-shaped leaves, waxy coatings, nutrient-poor soil, and low species diversity, including cedar pines, spruces, and firs.

Layers of Plants in Forest Ecosystems

• Emergent Layer: Tall trees (70-80 meters max) found only in tropical forests, which receive constant sunlight.
• Forest Canopy: Consists of closely spaced trees from 10-25 meters and up to 60 meters supporting monkeys, birds, insects, and reptiles.
• Understory: Refers to plants beneath the canopy that receive dim sunlight, with smaller trees typically 5-10 meters and shrub layers of 1-5 meters which are rare in tropical settings.
• Non-Woody Herbaceous Ground Cover: Rarely exceeds 10% of the forest area in tropical forests consisting plants and grasses.
• Moss, Cryptogam, and Shallow Soil Layer: Includes fallen logs, decomposing litter of leaves/twigs.

Forest Ecosystems

• One ton of carbon in wood or forest biomass recycles 3.67 tons of atmospheric carbon dioxide.
• Forests preserve water, soils, plants, and wildlife, and their destruction can aggravate droughts, soil erosion, increase pollution and pests.
• Tropical forests harbor at least half of Earth's species, and their loss significantly reduces biodiversity.
• Clearing and destructive logging are major global causes of species extinction worldwide.

Solutions for Forest Ecosystems

• Corporations can implement anti-deforestation policies that require suppliers and stakeholders to operate in environmentally-friendly ways, minimize paper use, and encourage recycling.
• Governments can reforest by replacing cut trees, support anti-deforestation organizations, and increase their sphere of influence.
• Individuals can recycle and use recycled products to reduce damage to forests.
• Estimate that India should have 33% of its land forested, while current forests cover about 12%.

Importance of Forests

• Forests consist of provision services (timber, medicine),
• Regulating services(air, CO2, erosion, habitat and natural hazard regulation.
• Cultural services ( aesthetic, educational and spiritual value).

Forest Exploitation

• Forests contribute to soil conservation by preventing soil erosion through plant root systems that reduce wind and rain velocity.
• They reduce atmospheric pollution by absorbing carbon dioxide and releasing oxygen via photosynthesis.
• Also control water flow, with thick humus layers acting like sponges to soak up rainwater which prevents runoff and flash floods.

Forest Depletion

• Forests are depleted due to overexploitation and deforestation, through factors like fuel wood consumption, industrial development, overgrazing, agricultural expansion, and developmental projects.
• Deforestation is the reckless or large-scale felling or cutting of trees for commercial and other purposes causing desertification, soil degradation, loss of vegetation and wildlife, changes in climate, environmental pollution, damage to ecosystems, and reduction in soil moisture.
• Large-scale forest depletion are caused by expansion of agriculture, urbanization, commercial exploitation, forest fires, mining, and forest diseases.
• Eroded soil, disrupted water cycles, biodiversity loss, heightened flood/drought risks, and contribute to climate change.

Control, Management and Conservation of Forests

• Preventing human settlement and agriculture in forests
• Enforcing controlled mining and grazing in forested areas
• Minimizing dam placement which contribute in rises in temperature, reduced precipitation, soil erosion, more frequent flooding, reduced soil productivity, and loss of biodiversity.
• Forest management promotes public/ political awareness of Joint Forest Management (JFM), social forestry, agroforestry, farm forestry, and biodiversity acts.
• Conservation involves wildlife parks and protected areas.
• JFM is a partnership between local communities and forest agencies for natural forest management.
• The Forest Department and a village Forest Protection Committee (FPC) engage in a JFM, where villagers protect forest resources from grazing, fire, and illegal harvesting in exchange for non-timber forest products and a portion of wood product sale proceeds.
• Social forestry involves managing, protecting, and afforestation of barren/deforested lands.
• Farm forestry involves growing trees or shrubs on farms to support agriculture and supplement farm revenue.
• Agroforestry interacts with agriculture and includes the agricultural use of trees.
• Forest conservation and management can take the form of regulated tree cutting, fire control, reforestation, development of national parks, botanical gardens, and seed banks.
• The Aravalli range, which spans about 692 km in North-West India, is rich in both biodiversity and mineral resources, including quartz, marble, and granite.
• Despite Supreme Court ruling in 1991 to end mining activities more than 400 formerly illegal mines continued in the area.
• Mineral extraction can create environmental hazards such as high radioactivity from uranium tailings, land subsidence from the underground burning of coalmines, hexavalent chromium contamination from chromite mining, and river pollution from iron ore mining.
• Mineral extraction can contribute to soil and groundwater contamination, surface water pollution, air pollution, and occupational health hazards.

Grassland Ecosystems

• A grassland ecosystem is the collection of plants, animals, and microorganisms in an environment where grasses are the primary type of vegetation.
• Grasslands occur naturally on all continents except Antarctica.
• Rainfall is average but erratic, and limited grazing improves net primary production while overgrazing leads to desertification.
• Three main types of grasslands exist: tropical grasslands, temperate grasslands, and polar grasslands.

Tropical Grasslands

• Located near the equator
• Border tropical rain forests, with high average temperatures and low/moderate rainfall.
• Cover Africa, large areas of Australia, South America, and India in semi-arid to semi-humid climate regions at subtropical and tropical latitudes.
• Savannas are present in Africa, marked by tall grass with scattered and stunted trees.
• Are home to zebras, giraffes, gazelles, antelopes, and lions.
• Deliberate burning releases significant amounts of CO₂, responsible for greenhouse gases.

Temperate Grasslands

• Have very cold winters and intense grazing.
• Summer fires prevent shrub or tree growth
• Include prairies in the US and Canada; pampas in South America and Argentina; velds in Africa; and steppes in Europe, Russia, and Asia.

Polar Grasslands (Arctic Tundra)

• Characterized by severe cold, strong and frigid winds with ice and snow.
• The climate is too harsh for tree growth
• Sunshine is almost constant in winter, with small annual plants and grass that grow in summer.
• Animals include arctic wolves, weasels, arctic foxes, and reindeer.
• Permafrost is a permanent thick layer of ice frozen under the soil supporting shallow lakes, bogs harboring mosquitoes, certain insects, and migratory birds.
• Other Grasslands: Desert Grasslands, Montane Grasslands and Flooded Grasslands.

Grassland Ecosystems

• Components: abiotic, biotic, producers, consumers and decomposers are similar to the forest ecosystem (see above)

Threats to Grassland Ecosystems

• Global warming can turn marginal grasslands into deserts by altering rainfall patterns.
• Conversion of land to row-crop agriculture reduces habitat for prairie wildlife.
• Expanding urban areas encroaches on grassland habitats.
• Drought-hardy and herbicide-tolerant crops like soybeans, wheat, and corn allow agricultural expansion into native grasslands.
• Single-crop farming can cause pest and disease easily spread leading to the use of toxic pesticides.

Grassland Conservation

• Requires educating people on soil protection and erosion prevention.
• Protecting and restoring wetlands is vital as they are parts of grassland ecology.
• Agriculture should rotate to prevent the sapping of nutrients.
• Dry season burning helps for fresh growth and to restore calcium.
• Planting trees as windbreaks.

Banni Grasslands Case Study

• Located on the southern edge of the Rann of Kutch's salt flat in Gujarat, India.
• Largest grassland in Asia, spanning 2617 sq. km.
• Declared a protected forest in 1955 under the Indian Forest Act, 1927.
• Has 40 grass species, 99 flowering plant species, native animals like the Indian wolf.
• Endure droughts every few years.
• A 1961 green revolution introduced the exotic species Proposis juliflora.
• Seeds were scattered to stop salinity intrusion and improve soil stability.
• The bushy trees propagate quickly, absorb water, do not allow native grasses to grow, and stop groundwater recharge, leading to grassland disappearance.
• Pastorial community relies on Banni grassland for grazing their cattle, but no proper roads or proper power in the Banni.

Banni Grassland Scenario

• Invasive species grew from 6% to 54% between 1979 and 2015 which greatly increased the problem of salinity, with an increase rate of 80 kms/year.
• The river that flows through the grassland is dammed by the government reducing the grassland salinity.

The Action for Protecting the Grasslands

• An NGO, SAHJEEVAN, and CFMCs are removing invasive species to regenerate the natural grasslands.
• They selected seeds from 8-9 varieties of grass species and restored about 20 hectares of grassland by mid-2022 using 26 CFMCs and scientist collaboration.
• Restoration efforts focus on invasive species removal, community engagement, research institution collaboration, grassland revival, and livelihood benefits.

Dams

• Benefits from dams include primary benefits like recreation (35%), stock/farm ponds (18%), flood control (15%), public water supply (12%), irrigation (11%) and hydroelectricity (2%). - Provide large quantities of high quality water for domestic and industrial use in both dry and arid regions. The Malampuzha Dam of India uses two canals to network servicing its reservoir of 42,090 Ha area.
• Excessive precipitation helps to reduce flood control and is effective for maintaining water level in rivers
• Renewable kind of electricity helps boost a country's overall socio-economic development.
• Navigation and waterway navigation and dams helps control levels of water. Ortona Lock and dam is the Okeechobee navigation system extends to the Gulf of Mexico. Hoover Dam major tourist attraction and over a million people visit annually
• Provide recreation for aquatic animals

Dams Problems

• Large quantity of forest and flora and fauna loss, water salinity, can be a factor for earthquakes, stagnation water retards plant growth, submergence of large areas of land, vector vectors and vector-borne diseases, population relocation

Mining

• Consist of: Prospecting, Exploration, Development, Exploitation, reclamination Mining is a hazardous career Araballi range: Sariska Tiger: Mining operations near Sariska Tiger has left many areas permanently infertile and illegal mining is still in progress. Mining and quarrying is creating problems like underground fires leading to landslides

Environmental Effects of Minerals

• Jaduguda and uranium and haria coal mines are very dangerous Kudremukh iron ore river pollution Pollution of ground water, air

Dam and Mineral Exploitation

• Timber extraction interrupts the normal forest nutrient cycle, promoting nitrification which reduces the nitrogen available to plants by approximately 50%.
• Habitat loss destroys animals and mining effects the ecosystem.
• Dam construction leads to downstream flooding after water spills, which leads to human death and causes plantlife an wildlife to be displaced.