Page 309 - Environment: The Science Behind the Stories

Causes Consequences

Degradation of
Overharvesting ecosystem function
Pollution
Loss of ecosystem
Habitat alteration services

Biodiversity Loss of
Growth loss food sources
in per capita
consumption
Loss of tourism
Human population and recreation
growth
Economic loss
Invasive species Loss of
sources of
Globalization medicines Health impacts
More Social disruption
Global
greenhouse gas climate change Loss of aesthetic
emissions and spiritual ties
with nature

Figure 11.16 The loss of biodiversity stems from a variety Solutions
of causes and results in many consequences for ecological
systems and human well-being. Arrows in this concept map As you progress through this chapter, try to identify as many
lead from causes to consequences. Items grouped within outlines solutions to biodiversity loss as you can. What could you
do not necessarily share any special relationship; the outlined personally do to help address this issue? Consider how each
action or solution might affect items in the concept map above.
shapes are merely to streamline the figure.

consumption. As researchers gain a solid scientific under- • Detoxifies and decomposes wastes
standing of the causes of biodiversity loss, we are also grap- • Stabilizes Earth’s climate
pling with its consequences (Figure 11.16) as our actions erode • Moderates floods, droughts, and temperature extremes
the many benefits that biodiversity brings us.
• Cycles nutrients and renews soil fertility
• Pollinates plants, including many crops
Benefits of Biodiversity • Controls pests and diseases
• Maintains genetic resources for crop varieties, livestock
Biodiversity loss matters from an ethical perspective, because breeds, and medicines
many people feel that organisms have an intrinsic right to • Provides cultural and aesthetic benefits
exist. However, losing biodiversity is also a problem for • Gives us the means to adapt to change
human society because of the many tangible, pragmatic ways
that biodiversity benefits people and supports our society. In these ways, organisms and ecosystems support
vital processes that people cannot replicate or would need
Biodiversity provides ecosystem services to pay for if nature did not provide them. The annual eco-
nomic value of just 17 of the world’s ecosystem services has
Contrary to popular opinion, some things in life can indeed be been estimated at over $48 trillion per year (p. 170)—more
free—as long as we protect the ecological systems that provide than the gross domestic product of all national economies
them. Intact forests provide clean air and water, and they buffer combined.
hydrologic systems against flooding and drought. Native crop
varieties provide insurance against disease and drought. Wild-
life can attract tourism and boost economies. Intact ecosystems
provide these and other valuable processes, known as ecosys- Biodiversity helps maintain ecosystem
tem services (pp. 21, 134–135), for all of us, free of charge. function
Maintaining these ecosystem services is one clear benefit
of protecting biodiversity. According to UNEP, biodiversity: Ecological research demonstrates that biodiversity tends to
enhance the stability of communities and ecosystems. Research
308 • Provides food, fuel, fiber, and shelter has also found that biodiversity tends to increase the resil-
• Purifies air and water ience (p. 103) of ecological systems—their ability to weather

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