plant survival
“
MANY PLANTS
COULD BE SAVED
through long-term conservation, and
hydroponics is a method that could be
useful for cultivation of plants.”
Matt Johnson is program manager
of Arizona’s world-renowned Boyce
Thompson Arboretum, which has
the mission to “create one of the
largest living repositories of arid land
germplasm in the world.” There are 3,200
desert plants to be found in this 320-acre
living classroom. Species taken from
the Earth’s many and varied deserts
and arid lands are displayed alongside
native Sonoran Desert vegetation.
“There are many kinds of plants
that can be grown hydroponically,
though most can be grown just
as well using more conventional
means,” says Johnson. “So, I don’t
know that hydroponics offers any
particular advantages for the purpose
of conserving rare plants. For some
species, it might be a practical
methodology, but unless there are
reasons the plants can’t be grown more
conventionally, you can accomplish
the same thing conventionally using
proper horticultural techniques or in a
greenhouse but without hydroponics.
And growing in sterile soil in a
container is also more cost effective.”
Johnson calls habitat preservation
the “ultimate goal” in this situation
and cites habitat loss as the single
biggest threat, closely followed by
climate change, slash-and-burn
agriculture, and even plant collectors
who have driven some species to the
brink of extinction.
“The ultimate goal of an ex-situ
conservation effort should be to
eventually return a plant to its native
habitat or, at least, to the wild in an
area where reintroduction can be
attempted. Even then, assuming an
area for a reintroduction would become
available, a major concern is that
cultivated plants are unintentionally
selected for traits that are adaptive
to horticulture and these same traits
may not necessarily be as adaptive to
survival in the wild.”
62
grow cycle
Given the choice between optimism
and pessimism, Johnson admits to
being somewhat pessimistic. “We’re
going to lose a lot of things, and even
putting current political climate aside,
altering the trajectory our society is
on—changing our ways—can’t be done
quickly enough to head off a lot more
problems that will come back and bite
us in the tail.”
One expert calls hydroponic
cultivation “a long shot,” while another
says it’s doable, but “seed-banking
and cryo-preservation should be used
to preserve as much genetic diversity
as possible.”
Even Dr. Merle Jensen, a pioneer
in soilless growing and a strong
proponent of plant growth and
reproduction in hydroponic liquid
culture versus solid media growing,
waffles a bit. “Hydroponics or
soilless growing in water or perlite or
vermiculite is one method that can be
used in the saving of plant species,
but it’s not a save-all solution,” he
says. “Historically, plant species have
come and gone and the technology
we have today to control all aspects of
growing crops or plants—in the ground
or above it—under the watchful eye of
horticulturists or scientists, could help
save some of those species.”