The ancient ingenuity of water harvesting – Kỹ thuật thu nước mưa tài tình từ thời cổ đại


Valuing Ecosystem Services

James Salzman, Valuing Ecosystem Services, 24 Ecology L. Q. 887 (1997).

Beneath the Arizona desert sun on September 26, 1991, amid reporters
and flashing cameras, eight men and women entered a huge
glass-enclosed structure and sealed shut the outer door. Their 3.15
acre miniature world, called Biosphere II, was designed to re-create
the conditions of the earth (modestly named Biosphere I). Built at a
cost of over $200 million, Biosphere II boasted a self-sustaining environment
complete with rain forest, ocean, marsh, savanna, and desert
habitats. The eight “Bionauts” intended to remain inside for two
years. Within sixteen months, however, oxygen levels had plummeted
thirty-three percent, nitrous oxide levels had increased 160-fold, ants
and vines had overrun the vegetation, and nineteen of the twenty-five
vertebrate species and all the pollinators had gone extinct. Eden did
not last long.1

What went wrong? With a multi-million dollar budget, the designers
of Biosphere II had sought to re-create the level of basic services
that support life itself-services such as purification of air and
water, pest control, renewal of soil fertility, climate regulation, pollination of crops and vegetation, and waste detoxification and decomposition.
Together, these are known as “ecosystem services,” taken
for granted yet absolutely essential to our existence, as the inhabitants
of Biosphere II ruefully learned. 2 Created by the interactions of living
organisms with their environment, ecosystem services provide both
the conditions and processes that sustain human life. Despite their
obvious importance to our well-being, recognition of ecosystem services
and the roles they play rarely enters policy debates or public
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