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When the rate of harvest exceeds
the rate of replenishment through
either reproduction or human
activities such as tree planting,
the harvest is not sustainable,
and without regulation could result
in the extinction or extirpation
of species.
A study of the IUCN’s Red List
in 2016 showed that 72 per cent
of species listed as threatened or
near-threatened are harvested at
a rate that means their numbers
cannot be balanced by natural
reproduction or regrowth. Some
62 per cent of species are at risk
from agricultural activity alone,
such as livestock farming, tree
felling, and the production of
crops for food, fuel, fibres, and
animal fodder.Protecting biodiversity
In reality, the five HIPPO threats
identified by Wilson are interrelated,
and there is generally no single
reason why any particular species
is endangered. Agricultural
development, for example, can
not only destroy a habitat, but can
also releases greenhouse gases into
the atmosphere, contributing to airThe building of railways across the
US was accompanied by hunters hired
to decimate the buffalo population that
had sustained Native American tribes.
By the end of the 19th century, only a
small number of wild buffalo survived.pollution and climate change. More
than 80 per cent of the species on
the IUCN’s Red List are affected by
more than one of the five major
biodiversity threats.
Biodiversity maintains the
health of the ecosystems of the
planet. Ecosystems are a delicate
balance of living creatures, both
plant and animal, as well as the
soil, air, and water in which they
live. Healthy ecosystems provide
resources that sustain human and
all other life, improve resilienceagainst natural disasters and
human-made shocks, including
climate change, and provide
recreational, medicinal, and
biological resources.
Although the threats to
biodiversity from human activity
are serious, ways to protect it
are being developed. Foremost
is a “sustainable” approach to
harvesting and agriculture that
allows species—such as fish, trees,
or crops—to be maintained at a
stable level and even increased
over time. Official protected status
for areas of land, water, and ice
can help sustain threatened
species, while national and
international agreements and
negotiations can mitigate the
impact of both legal and illegal
trade, such as poaching. Public
education also helps people to
better understand their potential
impacts on biodiversity and how
to protect it for future generations. ■Anthropogenic biomes
The biosphere—all the areas of
Earth and its atmosphere that
contain living things—consists
of biomes, which are large
ecosystems based on a specific
environment, such as desert or
tropical rainforest. The impact
of human actions on biodiversity
and the consequent reshaping
of much of the planet have led
ecologists to reassess biomes
and suggest that a designation
of anthropogenic (manmade)
biomes is now necessary.
Anthropogenic biomes aregrouped into six main
categories: dense settlements;
villages; croplands; rangeland;
forested; and wildlands.
Unlike other biomes, which
can range across continents,
anthropogenic biomes are a
mosaic of pockets over Earth’s
surface. According to ecologists,
more than 75 per cent of Earth’s
ice-free land has been affected
by at least some form of human
activity, particularly in dense
settlements (urban areas), which
account for over half the world’s
population, and villages (dense
agricultural settlements).THE ORDERING OF THE NATURAL WORLD
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