View
212
Download
0
Category
Preview:
Citation preview
Humans in the Biosphere
Chapter 6
A Changing Landscape
“Earth is an Island”All organisms- including humans -that live
on Earth share limited resources & depend of them for their survival.
Natural ecological processes sustain these resources (water, carbon, nitrogen cycles)
To protect these resources – we must understand how humans interact with the Earth
Humans and the BiosphereWe as humans depend on chemical cycles
(H20, C, N) to provide:a. breathable airb. drinkable waterc. fertile soild. storage & recycling of nutrients
We must understand how human activity affects these cycles
Human Activities that Affect the BiosphereHunting & gatheringAgricultureIndustryUrban development
Human activity has become the most important source of environmental change on the planet.
We do not fully understand how these activities affect our ecosystems
HumanActivities
that have changed the biosphere include
may have once caused often relies on the methods of thehave resulted in
which increased
Food supply Pesticide use Monocultureuse
Hunting andgathering Agriculture
Industrial growth
Urbandevelopment
Extinctions oflarge animals
Greenrevolution
High standardof living
Increasedpollution
Renewable ResourcesCan regenerate or can be replenished Not always unlimitedExample:
- Water can become limited by drought or overuse
Human activity can affect the quality of renewable resources such as:- land, forests, fisheries, air & freshwater
Nonrenewable ResourceCannot be replenished by natural processesWhen they are depleted –
they are gone foreverExample:
- coal- oil- natural gas (fossil fuels)
Sustainable DevelopmentWay of using natural resources without
depleting themProvides humans with what they need
without causing long term environmental harm
This can have a positive impact on the environment we create for ourselves & future generations
BiodiversityThe sum of the genetically based variety of all
organisms in the biosphereBasically, how all living things are so different!!!Greatest natural resourceThe many different species provides us with:
1. food2. industrial products 3. medicines (painkillers, antibiotics, heart, antidepressants & anticancer drugs)
When biodiversity is lost, potential sources of material with significant value to Earth & mankind may be lost with it
Types of DiversityEcosystem Diversity:
Variety of habitats, communities, and ecological processes in the living world
Examples:habitats ecological
processes1. deserts 1. water cycle2. mountains 2. carbon cycle3. rain forests 3. nitrogen
cycle4. oceans 4. phosphorus cycle
Types of DiversitySpecies Diversity
Refers to the # of different species in the biosphere
Scientists have identified & named about 1.5 million species
They estimate millions will still be discovered
Genetic DiversityRefers to the total of all the different forms of
genetic information carried by all organisms living on Earth today (DNA)
Threats to BiodiversityAltering habitatsHunting to extinctionIntroducing toxic compounds into food
websIntroducing foreign species to new
environments
Recommended