All changes are made in blue
This is legit. Pretty awesome. I think you should add more pictures though. Also make
sure to format it properly (Garamond ect.)
Phenology is the study of the timing of natural events in the biological world (“What is
Phenology”). These events include everything from what time flowers bloom during the year to
the timing of whale migrations. Organisms often align themselves with phenological events in
order to interact with one another through predation or symbiosis. Ecosystems are heavily reliant
on events working time in order to function smoothly.
There are three major abiotic factors that affect phenology. The first is precipitation, or
the amount of rain that an area receives. Plants rely on water to further their life cycles, while
some insects use pools of water to breed and lay eggs. Precipitation rates often vary throughout
the year, signaling changes in organisms which are rainfall-dependent.
The second abiotic factor is the amount of sunlight an area receives. In the northern
hemisphere, spring and summer occur when the Earth is farthest from the sun but receives more
radiation due to the tilt of the Earth’s axis. During this time, days are longer and nights shorter.
Fall and winter occur when the Earth is closest to the sun, but receives less radiation because the
Earth is tilting away from the sun. Nights grow longer during this period and the days shorter.
This is reversed in the southern hemisphere. Plants and other organisms that photosynthesize
need sunlight to complete their metabolic cycles. When days grow shorter and the amount of
light increases, plants will revert to anaerobic respiration and often go into a dormant stage. For
example, trees will lose their leaves during fall and winter. When the amount of light increases,
the plants will grow leaves to capture the light for photosynthesis again.
The final abiotic factor that affects phenology is the temperature of an area. Organisms
often have temperature-specific gene and behavioral responses which are triggered by an
increase or decrease in temperature. For example, dogwood trees begin to bloom once the area
reaches a certain temperature which corresponds with spring in most areas, and many animals
begin to lose winter molts after temperatures increase and snow would no longer be present.
Temperature also dictates the length of time an organism may survive in a certain area.
Mosquitoes and many other insects begin to breed as the temperatures grow warmer and them
die off or hibernate as cooler temperatures approach, creating a natural cycle of life and death.
Check This Video: http://www.youtube.com/watch?v=RNs3XpRmRfI for more on how
phenology is defined and how it works.
Of the three factors, temperature and precipitation are the two which are most affected by
climate change. Human actions which cause an increase in greenhouse gases not only result in a
warmer overall temperature, but more specifically affects the established climate in certain areas
with dramatically different results. Locations that have historically been arid could become more
inhospitable, perhaps becoming colder and receiving less rainfall. Areas that are warm and wet
could become warmer and receive more violent storms. This change in precipitation and
temperature could affect the phenological cycles of some organisms and not others, throwing off
the delicate timing that the organisms have established over thousands of years. Additionally,
humans change the environment through urbanization and deforestation. In urban areas,
temperatures can deviate from unaltered landscape due to changes in albedo and result in some
species receiving warmer or cooler temperatures than on average. Once again, phenological
cycles that depend on temperature would be altered by this urbanization effort.
Climate change’s impact on phenology is indirect. Overall, the changing climate affects
the three factors that affect phenology directly. Climate is the composite or generally prevailing
weather conditions of a region, such as temperature, air pressure, humidity, precipitation,
sunshine, cloudiness, and winds, throughout the year, averaged over a series of years. As these
factors are changing the phenology in different environments changes as well. For example, take
a flower that blossoms when the temperature is between 50 and 65 degrees Fahrenheit. If the
temperature in a specific town begins to grow warmer earlier over a few years, the blooming date
of the species will move forward in response. This could be potentially harmful for animals or
insects that are dependent on this species.
Case Study: Edith’s checkerspot butterfly (Adapted from Hannah 9)
The Edith’s checkerspot butterfly of the Nymphalidae family lives in the northwestern
United States, particularly along the Sierra Mountains. These butterflies fed primarily upon the
nectar of the blue-eyed Mary, whose blossoms while the larvae pupated and the adults emerged,
around March to June (“Butterflies and Moths”). However, warmer temperatures have caused the
blue-eyed Mary to bloom earlier than the adults emerged. The checkerspot has recently begun to
feed upon the English plantain more frequently as a result, or have moved to higher elevations
where the blooming of the Mary matched the butterfly’s normal flight time. The blue-eyed Mary
now lacks a primary pollinator, which the English plantain has gained, and is now less capable of
reproducing.
As climate change alters the timing of phenological events, organisms that rely on one
another can no longer depend on their relationships to occurs at the same time. As with the case
of the Edith’s checkerspot and the blue-eyed Mary, organisms that have a symbiotic relationship
might find one partner arriving too early or too late, which could result in starvation or other
undesirable effects among one or both of the partners. Conversely, other less-desirable organisms
might benefit from the change in phenological events which could cause considerable damage.
As the weather grows warmer and wetter in some parts of the world, insects are breeding and
developing at a more aggressive rate, and staying around for longer than before. When this
occurs with disease vectors, such as the mosquito, the rate of deadly infections could increase
exponentially (USA NPN).
Lab:
A potential lab that could be performed to show the effects of a changing climate is to
change the different amounts of sunlight and water that plants are receiving. This will effectively
demonstrate the responses plants can have to a climate that is constantly changing. To perform
this lab you will need: 4 cosmos flowers, 2 heat lamps and access to water.
1. Place the first flower under a heat lamp. For this flower you will maintain the same
amount of heat, representing an increase in temperature. You must also provide the
cosmo with 300 mL of water each day to represent normal water amounts.
2. Place the second flower in sunlight and give the flower 300 mL of water a day. This is
your control plant.
3. Place the third flower under a heat lamp. This plant will recieve 600 mL of water daily.
The increase in water as well as the extra heat represents a climate where an increase in
heat and water has happened.
4. Place the fourth flower into sunlight and give the plant 600 mL of water a day. This plant
represents an environment where no change has taken place in the temperature, but the
amount of water has increased dramatically.
5. Observe the plants daily. Record any observations about the plants including, which plant
blooms first, which plant blooms last, and which factor has the greatest impact on the
change in timing patterns for the plant.
To further study the effect of climate change on phenology satellite data is a very useful
tool. Satellites have an ability that humans themselves do not have, to scope out changes in
phenology in large areas over large amounts of time. This allows satellites to map the overall
effect of climate change on phenology with ease. As an example below is included photos taken
from space of the Southeast United States.
This is data from 2001.
This is data from 2012.
In these satellite images the maximum NDVI is represented. NDVI stands for the
normalized difference vegetation index, which is a graphical indication to analyze whether an
area contains live green vegetation. When viewing these images make sure to ask yourself things
like how have the max NDVI months changed for the Southeastern USA between 2001 and
2012. What are some factors that could account for this change? What consequences could this
change create? Keep in mind that climate change can have both negative and positive effects in
different areas.
In addition to ecological damage, changes in phenological events could also cause
financial damage. Insects that develop more quickly and remain for longer periods of time could
cause more damage to crops and affect the size of harvests. This could be even more devastating
if helpful creatures, such as pollinators and natural pest control species, are not available to tend
to the crops because of the changing climate. Additionally, several festivals around the world
depend on phenological events. The cherry blossoms in Washington D.C. bring many tourists in
from around the world, who are now often disappointed to find that the time for the blossoming
already passed (USA NPN).
Glossary
Phenology-the study of the timing of natural events in the biological world
Abiotic-non-living and not from living organism
Climate-composite or generally prevailing weather conditions of a region, such as temperature,
air pressure, humidity, precipitation, sunshine, cloudiness, and winds, throughout the year,
averaged over a series of years
Symbiosis-a relationship between two different organisms that benefits at least one of the
organisms
Vector- an organism that carries a disease
Normalized Difference Vegetation Index-a graphical indication to analyze whether an area
contains live green vegetation
Works Cited
"Butterflies and Moths of North America | Collecting and Sharing Data about Lepidoptera."
Butterflies and Moths of North America | Collecting and Sharing Data about Lepidoptera. Web.
Hannah, Lee Jay. Climate Change Biology. Burlington, MA: Academic, 2011. Print.
"What Is Phenology? - National Wildlife Federation." What Is Phenology? - National Wildlife
Federation. Web.
"USA NPN National Phenology Network." Why Phenology? Web. 19 May 2014.
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