Changes in habitat can disturb populations

• Changes in the interactions among the living and nonliving components of an ecosystem cause change in the system.
• Factors (natural and human-caused) can positively and negatively affect the cycles of matter and the life processes of living things within an ecosystem.
• Humans are a natural part of the ecosystem.
• Humans use the ecosystem to meet their basic needs, such as to obtain food .

Disruptions in ecosystems can change species competition

• Human input can disturb the balance of populations in a habitat.
• These disturbances may lead to a decrease or increase in a population's size.
• Since populations in an ecosystem are interdependent, these disturbances can have a ripple effect throughout the larger ecosystem.

Variations in biotic and abiotic factors can change ecosystems

• The interaction of humans with the dynamic ecosystem may lead to changes in climate, water supply, air quality, energy production, ocean acidification, and waste management .

You should be able to:
• describe ways that human interaction has altered habitats positively and negatively.
• describe the relationship between human food harvest and habitat stability.
• debate the pros and cons of human land use vs. ecosystem stability.
• compare population disturbances that affect competition among species and species survival.
• use evidence to describe the impact of human activity on the biotic and abiotic factors within an ecosystem.