Second Reflection Journal

Earth systems are all interconnected. When looking at the big picture, every division is
not concrete, but easily permeable. This week, we looked into the Earths albedo and
feedbacks, how plants in different ecosystems grow and adapt differently, and even how plants
communicate through chemical signals. To demonstrate the idea that Earth systems are
interconnected, the DaisyWorld lab offers interesting information on how the reflectivity of plants
on a planet could determine and change climate. In the DaisyWorld lab, the model
demonstrated a planets natural feedbacks, or reactions that occur when a major climate
change takes place. When the planet got too warm, the number of white flowers would grow,
allowing for increased reflectivity and the cooling of the climate. When the planet got too cold,
more absorbent black flowers grew more plentifully, causing a warming. This balance can only
occur because albedos differ widely in the color spectrum, allowing for surfaces that can provide
significant feedbacks. In addition to the DaisyWorld lab, the documentary on plant
communication provided key information about how local ecosystems are interconnected.
Douglas fir trees are connected to other fir trees throughout the forest. Those trees are
connected to fungi roots. Fungi roots provide nutrients to the trees while trees provide sugars to
the fungi. When looking at this forest ecosystem as a whole, it is evident that the Douglas fir
trees and the fungi benefit from each other, and interesting that the fir trees can distribute the
nutrients to the smaller, younger trees to ensure proper growth. This key relationship shows
interconnectedness, and so does the information in the videos on plant communication. The
documentary and video show that plants can communicate with each other and with insects for
survival. The wild tobacco plant has many predators but releases nicotine to kill them off. This
doesnt always work, so the plant is able to send out a volatile chemical signal notifying the
predator of their grazer to come and eat. Plants interaction with one another and insects show
that different levels of an ecosystem are interconnected in new, more personally intelligent
ways.
Science, as always, requires testing questions and claims. This week, many questions
arose after situations involved trying an experiment that spurred a new, testable claim. The plant
documentary and video gave examples of many situations during which new questions could be
asked. Questions such as How do plants find the food theyre looking for?, Can a Dotter Vine
choose its victim? If so, how?, and Do stranger plants interact differently than sibling plants?
were asked. These questions required experiments, many of which required the observation of

how a plant communicated or reacted over a longer period of time. The first question was tested
by observation of a sped-up root searching for a nutrient soil patch. The second question
involved seeing which victim a Dotter Vine would select over several setups, and then
separating the chemical identification from the actual selected plant. The third question involved
observing how roots grow and how they grow with respect to each other, and then separating
the chemical identification, once again, from the sibling roots. In each of these situations, the
plants responded and reacted in clear, distinctive ways. And by separating each variable (like
taking away the chemical identification element) the correct catalyst for the interaction could
be properly identified. In contrast to this very observationally-dictated method of
experimentation, there are methods of experimentation in comparison. Ben Cook and his team
of scientists studied the archaeological records account of how, in Yucatan, in Mesoamerica
around 800 CE, forests were quickly being replaced by agricultural land. Cook compared this
trend with data precipitation sources such as stalagmites, which are changed by atmospheric
moisture. A clear correlation (but perhaps not causation) existed between increased farmland
and drought. Cook and his team concluded that precipitation declined by 10-20% when
deforestation was peaking. The evidence was there, but theories then had to be made. Cook
predicts that farmlands have higher albedos than forests, and that there is less absorbed energy
in the ecosystem for convection and precipitation when farmlands replace forests. This
experiment is just another example of how new climate questions arise, are tested, and bring
about even more questions for experimental consideration.
Climate change has many consequences, but there are natural feedbacks and reactions
that exist to reverse, accommodate, or continue changes. In the DaisyWorld lab, negative
feedbacks were observable. White or black flowers grew or shrunk in population size to alter the
albedo of the planet and stabilize the climate. However, these flowers, like many organisms on
Earth, cannot survive outside a certain temperature range. Similarly, many of the organisms
helping to stabilize climate may die because of climate changes too extreme for their tolerances.
Still, plants are learning and have evolved and adapted to accommodate special climate and
weather conditions. In the C3/C4 lab, it was demonstrated that plants have evolved and adapted
to function more efficiently in their specific ecosystems and seasonal weather behavior
conditions. For example, C3 plants are built to thrive in temperate or cool-seasons. They require
fewer enzymes to photosynthesize, and are therefore more efficient in normal light conditions.
Contrastly, C4 plants are not as common, and are found in very hot, dry climates. C4 plants
cycle carbon dioxide into four-carbon sugar compounds, and use the extreme sunlight to their

advantage. These two plant types, C3 and C4, have evolved to function best in their
environments. This could suggest future evolutionary possibilities allowing adjustment to climate
changes. However, current climate changes are occurring too quickly for any evolutionary
event.
Still, this is not to suggest that organisms will do their best with their surroundings for as long as
they can. The plant documentary and video revealed that plants have developed ways of
sensing that assist in ensuring they will grow to their best ability. They use senses such as
proprioception, coiling, and phototropism to make the most of their conditions and receive
enough light and nutrients. This is hopeful when considering future climate changes on
ecosystems. However, it is possible that future climate changes could cause these plants to be
tricked. Their photoperiodism, or the ability to determine which season it is, could be
compromised due to the increasing temperatures on Earth.