Travel Reference
In-Depth Information
species in such an ecosystem loses its niche, its demise will drag other spe-
cialists down with it.
Some of these species will probably remain unknown to science, and will
perish before we even have a chance to meet them. The bamboo lemurs of
the Ranomafana Forest have a unique large intestine, its inner surface stud-
ded with bulges. Bacteria inhabit these bulges, but we know little about them,
just as we know little about the crowds of bacteria that inhabit the crops of
hoatzins. Do these bacteria help the lemurs extract the nourishment from
the woody pulp of the bamboos without exposing them to the dangers of
cyanide poisoning?
We may never know. The fl ickering fi res that lick away at the outskirts of
the fragile Ranomafana forest may soon blaze through the park and sweep
away the lemurs and the many other species that depend on them. Then this
magical world, built by speciation upon speciation, will be no more. 4
Why some ecosystems are so rich in energy,
ecological niches, and species
All of our planet's living systems ultimately depend on the sun. It is true that
some unusual deep-sea ecosystems are powered by energy-rich molecules
such as hydrogen sulfi de that are released by the Earth's volcanic activity and
that are used by specialized microbes, but most of the creatures that inhabit
these black oceanic depths are descended from organisms that once basked
in the sun far above.
Why are some ecosystems so rich, and how can they generate and sup-
port so many species? To understand this, we must look at the fl ow of energy
in dif erent ecosystems.
Although the sun is the ultimate source of energy, it is utilized in dif er-
ent ways in dif erent ecosystems. Much of the intense sunlight that bathes the
clear waters of tropical oceans is wasted. The few tiny animals and plants that
fl oat there are limited, not by energy, but by a shortage of mineral nutrients.
The water is beautiful, blue, and crystal clear, but it is in ef ect a desert. Nitro-
gen, calcium, phosphorus, and iron, all essential to life, are in short supply.
 
Search WWH ::




Custom Search