Natural Resources and Environmental Sustainability
Natural Resources and Their Importance
Natural resources are living things or materials that humans use to meet their needs. These resources can be either renewable or nonrenewable.
Water Resources
Water is an essential resource, indispensable for life. Fishing activities are prominent in the Atlantic ports with freezer trawlers and deep-sea fishing, yielding seafood. Artisanal fisheries are common in the Mediterranean area. Andalucía is the second-largest fishing region in Spain, after Galicia.
Forest Resources
Forests are an important resource, providing wood, cork, fruit, leaves, herbs, and serving as suitable locations for tourism and sports.
Livestock
Due to weather conditions, grasses are not abundant, limiting cattle ranching. Sheep and goat farming are more prevalent.
Depletion of Resources
Nonrenewable resources are depleted within a few years, including oil, natural gas, and coal. Other resources are renewable.
Environmental Pollution
Air Pollution
The combustion of coal and hydrocarbon gases releases CO2 into the air, accumulating in the atmosphere and increasing the greenhouse effect.
Water Pollution
Water is contaminated by industrial and urban waste, fertilizers, and agricultural pesticides. The sea also suffers from pollution caused by oil spills from damaged oil tankers.
Soil Pollution
Air pollutants can enter the soil, for example, through rain.
Climate Change
Global warming is due to the enhanced greenhouse effect and ozone depletion in the atmosphere. These factors contribute to climate change, characterized by a general increase in average temperature on Earth.
Waste Management
Domestic Waste
Domestic waste includes commercial and construction debris. Agriculture, livestock, and forestry activities generate animal feces and plastic from greenhouses. Mine tailings produce traces of minerals and rocks with no economic value.
Industrial Waste
Industrial waste varies depending on the industry. Chemical industries produce hazardous waste, while nuclear power plants and hospitals generate radioactive waste.
Alteration of Food Chains
Causes such as forest clearing, fires, pollution, and fragmentation of ecosystems by urban buildings and communication routes lead to a loss of biodiversity and damage to the ecological balance.
Possible Solutions: Environmental Policy
Gradually implementing environmental policies will promote waste recycling, wastewater purification, reforestation, rural land management, building land regulations, fishing moratoriums, and the creation of protected areas.
Waste Recycling
Some waste is disposed of in landfills, while others are transformed or buried in concrete drums (e.g., radioactive waste). The main recyclable materials include:
- Paper and paperboard, which are easy to recycle.
- Glass, which is also easy to recycle into new glass.
- Plastic, which poses a major problem due to its abundance.
- Aluminum, which is abundant but expensive to manufacture.
- Iron and copper, which are traditionally recycled.
- Organic materials, which can be composted to create organic manure.
Sustainable Development
Sustainability means:
- All peoples on Earth have the right to develop technologically and economically.
- Natural resources should be exploited at a rate not exceeding their renewal rate.
- Polluting waste must never exceed the environment’s capacity to remove it naturally.
- Ecosystems should be preserved for future generations.
Biotic Factors in Ecosystems
Biotic factors are the different types of relationships that develop among living things in an ecosystem.
Levels of Organization
- Individuals: All beings capable of performing the vital functions of nutrition, relationships, and reproduction (e.g., an olive tree).
- Species: A group of individuals with similar physical characteristics that can interbreed and have fertile offspring.
- Hybrid: An individual whose parents are of different species.
- Population: A group of individuals of the same species that occupy a given area over a certain period of time.
Relationships Between Living Things
Intraspecific Relationships
- Competition: Individuals of the same population compete for resources like food.
- Family Association: Groups of individuals of the same family.
- Gregarious Association: Large groups of individuals not necessarily related to each other.
- Colonial Association: A large number of individuals from the same ancestor living together continuously due to lack of mobility.
- State Association: A large number of individuals organized in castes, each with a specific mission or job.
Interspecific Relationships
The most common and important interspecific relationship is based on food.
- Interspecific Competition: Individuals of different species compete for the same food.
- Predation: One individual, the predator, feeds on another living organism, the prey, which it hunts and kills.
- Parasitism: One organism, the parasite, feeds off the body of another, the host.
- Mutualism: Individuals of both species benefit mutually. When neither individual can live separately, the relationship is called symbiosis.
- Commensalism: One individual provides food or shelter to another without being benefited or harmed.
Trophic Organization of Ecosystems
Food is essential for life. Organisms in an ecosystem are categorized based on their role in the food web:
- Producers: Organisms that produce organic matter from inorganic matter through photosynthesis. They are autotrophs, including plants, algae, and some bacteria.
- Consumers: Organisms that obtain organic matter from other living organisms. They are heterotrophs, including animals and some fungi. There are primary consumers (herbivores), secondary consumers, and tertiary consumers (carnivores).
- Decomposers: Heterotrophic organisms that feed on the remains of dead organisms and their waste products, mainly bacteria and fungi.
Photosynthesis
The production of organic matter from inorganic matter can only be performed by plants, using a green pigment called chlorophyll. Chlorophyll is found in chloroplasts within leaves and green stems, giving them their color. Photosynthesis requires energy, which plants, algae, and bacteria obtain from sunlight.
In photosynthesis, carbon dioxide, water, and light energy are used to produce glucose and oxygen. The reaction can be written as:
CO2 + H2O + Energy → Glucose + O2
CO2 is absorbed from the air through stomata in the leaves. H2O is taken up from the soil by the roots. Energy is absorbed from sunlight by leaves and green surfaces. Glucose, a type of sugar, is formed and stores energy. It remains in the plant and serves as food. Oxygen (O2) is released into the air through stomata in the leaves and is used for respiration by most living beings, including plants themselves.
Photosynthesis is a fundamental process for life on our planet.
Food Chains and Food Webs
A food chain is a linear sequence of organisms in which each organism is eaten by the next. For example:
Carrot → Rabbit → Fox
A food web is a more complex network of interconnected food chains. For example:
Fruit → Mouse or Bird → Snake or Eagle
Ecological Pyramids
Ecological pyramids represent the relationships between trophic levels in an ecosystem:
- Numbers Pyramid: Represents the number of individuals at each trophic level.
- Biomass Pyramid: Represents the amount of organic matter at each level.
- Energy Pyramid: Represents the energy available at each level.
Cycle of Matter and Energy Flow
In an ecosystem, matter cycles through different organisms, following this general pattern:
Inorganic Matter → Producers → Consumers → Decomposers → Inorganic Matter
Technology and the Environment
The environment encompasses both the natural environment (ecosystems) and the social environment (humans and their activities). Humans interact with the natural environment to obtain resources and fulfill their needs. Technology can both impact and be used to address environmental challenges.