Write your abstract here.
Scientists Find that All Plants Live and Die According A Precise Scale.
In a
striking revelation,
scientists have discovered that all plants
live and die by a precise and simple rule. Scientists have found for
the first time that plants can self-regulate their populations to
maintain stability and optimize their lives, and that the lengths of
their lives are precisely related to their mass. Even more incredible,
a single scaling power for lifespan holds true across the entire
spectrum of plants, from minute single-celled phototrophs to the
massively majestic redwoods. Scientists previously understood that animals’ lifespans are somewhat
scaled to the species’ body size, with elephants living much longer
than mice. Plant biologists have predicted a similar connection in
plants, but a full study had never been conducted until recently.Researchers Núria Marbà, Carlos Duarte and Susana Agustí at the
Mediterranan Institute for Advanced Studies—a joint institute between
the CSIC (Spanish Council for Scientific Research) and the University
of the Balearic Islands in Esporles, Spain examined more than 1,000
reports of plant birth and mortality rates across a wide spectrum of
species, discovering that the connection holds with extreme precision.The researchers found that both
population mortality rates and
population birth rates of all plant species scale as the –1/4 power of
plant mass. In other words, the smaller a plant, the higher its
mortality and birth rates, meaning the shorter its lifespan. Hence,
plant lifespan scales as almost exactly the 1/4 power of plant mass. “The functioning of biological systems depends to a large extent on
their metabolism, i.e., on how they process energy and materials, such
as light, water, and nutrients,” Marbà explained to PhysOrg.com. “Small
plants require fewer resources per unit of time than large ones, and,
therefore, they are able to turn over the individuals of their
populations faster than large plants. As plant size increases, more
resources and time are needed to produce a fully grown individual, and
thus their lifespan increases, resulting in small plants having shorter
life spans than larger ones.” One very interesting aspect of these relationships is that mortality
and birth rates is nearly identical within a species, keeping the
population stable. Nature has clever reasons for this perfect cycle,
which include stabilizing carbon cycling, optimizing plant life
histories, and stabilizing the ecosystems the plants inhabit. The
scientists suggest that, to achieve this balance, plant mortality rates
have evolved to match the birth rates. Although they have found the delicate balance between mortality and
birth rates, the actual mechanisms governing plant life and death are
still unknown. Controls probably include an assortment of metabolic
processes interacting at all levels, from molecular on up, which would
include respiration, reproduction, cellular damage, and structural
imbalances. Plants retain their reproductive capacity throughout their
lives, unlike animals. Therefore, evolution might put greater selective
pressure on plants’ lifespans. Similar studies are bring planned to
continue the effort to unlock the many mysteries of the green kingdom. Galaxy Reported October 24th, 2007.