Biomes, Mutations, and Human-Environmental Interactions
Biomes of the World
b) The Taiga Coniferous Forest
Characteristics: Low annual average temperatures, but above 0°C. Precipitation usually falls as snow.
Location: Between 45° and 60° North latitude, covering large areas of Canada, the United States, Russia, Siberia, and Scandinavia. Also found in subalpine mountain regions.
Flora: Pine and fir forests. The evergreen canopy creates dense shade year-round, hindering the growth of herbs and shrubs.
Fauna: Squirrels, beavers, bobcats, wolves, deer, woodpeckers, and numerous insects, notably wood-eating beetle larvae.
c) Temperate Deciduous Forest
Characteristics: Temperate climate with warm summers and cold winters, and regular, abundant rainfall throughout the year.
Location: Extends from Siberia across central Europe to the northern Iberian Peninsula. Also found in Southeast Asia and the eastern United States. Human activity and intensive cultivation threaten this biome.
Flora: Deciduous trees such as beech, oak, and chestnut.
Fauna: Herbivores like squirrels, rabbits, deer, and mice, which are preyed upon by foxes, wolves, brown bears, wildcats, and snakes. Birds and insects are also abundant.
d) Mediterranean Woodland (Encinar)
Characteristics: This ecosystem thrives in specific conditions, making it globally rare but common in the Iberian Peninsula. Hot, dry summers and mild winters characterize this biome. Rainfall is scarce but torrential, concentrated in spring and autumn.
Location: Mediterranean basin, with small areas in California, Chile, South Africa, and Australia.
Flora: Strawberry trees, juniper, and Phoenician juniper in colder areas. Carob, palm, olive, and mastic trees, along with thyme, rockrose, heather, lavender, and rosemary bushes, are common in warmer areas.
Fauna: Imperial eagle, short-toed eagle, lynx, deer, roe deer, chameleon, rabbit, mouse, partridge, wild boar, numerous insects, small birds, and reptiles (lizards and snakes).
e) The Desert
Characteristics: Low precipitation and extreme temperatures, both hot and cold.
Location: Sahara Desert, northern Chile, western United States, central Australia, Tibet, etc.
Flora: Xerophytic plants adapted to water scarcity, such as cacti, succulents, and agave.
Fauna: Desert foxes, camels, rodents, scorpions, insects, and reptiles.
f) The Grassland (Pradera)
Characteristics: Irregular rainfall with distinct wet and dry seasons. Hot summers and cold or mild winters.
Location: Inland continental areas, including the African savanna, Argentinian pampas, Russian steppes, and central U.S. grasslands.
Flora: Tall grasses that flourish during the wet season and dry out during the dry season, interspersed with shrubs and trees.
Fauna: Large herds of herbivores like wildebeest, buffalo, horses, antelopes, gazelles, zebras, and kangaroos.
g) The Equatorial Rainforest
Characteristics: High temperatures and heavy, almost daily rainfall year-round. The richest and most diverse biome.
Location: Areas near the equator: Amazon Basin, equatorial Africa, and Southeast Asia.
Flora: Evergreen trees exceeding 45 meters in height, stratified due to light competition. Epiphytes and climbers are abundant. Herbaceous and shrub layers are limited due to low light penetration. Lush and diverse vegetation with thousands of tree species in relatively small areas.
Fauna: The most abundant and diverse on Earth, including reptiles and small to medium-sized monkeys.
h) The Tundra
Characteristics: Annual average temperatures below 0°C. Very low precipitation, mostly snow. Permafrost (permanently frozen subsoil) and mollisol (surface layer that freezes in winter and thaws in summer).
Location: Near the polar circles, above 60° latitude N and S, and high mountain peaks.
Flora: Mosses, lichens, grasses, sedges, and shrubs.
Fauna: Abundant flies and mosquitoes.
Genetic Mutations
Mutations are spontaneous, random changes in a cell’s genetic information. While mutations can occur in any cell, only those in gametes (eggs and sperm) are passed on to offspring.
- Gene Mutations: Changes in a gene’s nucleotide sequence, often during DNA replication. These changes can involve nucleotide substitutions, insertions, deletions, or relocation. A mutated gene often produces a non-functional protein, leading to genetic diseases.
- Chromosome Mutations: Changes in chromosome number or structure, often due to errors in chromosome separation. These mutations can be lethal or cause significant diseases.
Humanity’s Relationship with the Environment
Humans interact with their environment in three main ways:
- Resource Extraction: Utilizing matter and energy to meet physiological, socioeconomic, cultural, and other needs.
- Environmental Impacts: Alterations to the environment caused by human activities, either directly or through waste generation.
- Environmental Risks: Processes or events that can harm human health, safety, or property.
Depletion of Natural Resources
Resources are categorized based on their availability:
- Non-Renewable: Exist in fixed amounts, formed over long geological timescales. Examples include fertile soil, minerals, fossil fuels, and nuclear fuel.
- Renewable: Not depleted through use. Examples include solar, tidal, and wind energy.
- Potentially Renewable: Replenished by natural processes relatively quickly, but can be exhausted if overused. Examples include food (plants and animals), forest resources, freshwater, geothermal energy, hydropower, and biomass energy.
Non-renewable resources will eventually be depleted. Current consumption rates suggest many will only last for a few generations.