Biology Now, 2e

(Ben Green) #1
The Dirt on Black-Market Plants ■ 297

Figure 16.12


The greatest threat to endangered
cacti is illegal trade
Like orchids and cycads, the main threat to
most species of cacti is illegal trade. Collectors
pay high prices to smugglers who are willing to
risk fines and prison time to meet the demand.

the illegal plant trade “a major conservation
challenge that has been almost completely
overlooked.”
“It’s hard to get people to care about plants,
and nobody can care if we don’t have data to show
it’s a problem,” says Phelps, who is now trying
to engage governments and experts to raise
awareness and initiate policies that will better
regulate plant trade. At the CITES conference
in September 2016, country delegates increased
protections for a large number of plant species,
including ponytail palms, which are in demand
as houseplants, and all rosewoods, whose wood
is used to manufacture fine musical instruments.
“All these plants are part of a larger ecosys-
tem,” says St. John. “They serve important
purposes in temperature regulation, in creating
oxygen, and more. We need to recognize that
plants are an integral part of a healthy ecosys-
tem and key to the diversity of life.”

absorb nutrients from the soil (see “Fungi Play


Wel l w it h O t her s” on page 287).


Despite that assistance, fungi and plants are


not always close friends. Fungi are the most


significant parasite of plants: they are responsi-


ble for two-thirds of all plant diseases, causing


more crop damage than bacteria, viruses, and


insect pests combined.


Like many plants (and animals and protists),


fungi can reproduce both asexually and sexu-


ally. Some species appear to multiply only


asexually, and most multicellular fungi can


reproduce asexually through fragmentation—


that is, by simply breaking off from the mother


colony. When fungi do reproduce sexually, they


do not have distinct male and female individ-


uals. Instead, a sexually reproducing myce-


lium belongs to one of two (or more!) mating


types. Each mating type can mate successfully


with only one of the other types. After mating,


a fruiting body is formed that may be large


enough to be readily observed.


Fungal fruiting bodies release offspring as


sexual spores. A spore is a reproductive struc-


ture that can survive for long periods of time in


a dormant state and will sprout under favorable


conditions to produce the body of the organ-


ism. Spores released from a fruiting body that


is raised up in the air are better able to catch a


ride on wind currents or to attract animals that


can carry them far and wide. Many fungi also


produce asexual spores.


Fighting for the Future


The illegal sale of plants and fungi could drive


species to extinction. In 2015, for example, the Inter-


national Union for Conservation of Nature (IUCN),


a global environmental authority, announced that


31 percent of cactus species—renowned for their


unique forms and beautiful flowers—are in danger


of extinction, and that the greatest threat to these


plants is illegal trade (Figure 16.12).


During his studies, Phelps observed traders


selling plants that are highly endangered in


the wild. He published results from his thesis


in 2015 in the journal Biological Conservation,


pleading with scientific and policy communities


for a greater focus on these plants and calling


ANNE ST. JOHN


Anne St. John is a biologist with the Division
of Management Authority for the U.S. Fish and
Wildlife Service.
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