Notes of a Queens College Naturalist

Field Biology on Long Island

Spring Flowers in Central Park and Climate Change in New York

Filed under: Uncategorized — jakim88 at 8:12 am on Sunday, February 23, 2014

Central Park today welcomes the first crocuses emerging from the melting snow and the deep green water-loving buttercups (Ranunculus ficaria) cover the entire ground by patches of mud and melt-water streams in the North Wood. Indian straw-berries have made their appearance and the spring onions are ready for salad, amongst many more species. Spring flowers get a head start on growth in the cavities between the moist earth and snow-blanket above so that they may photosynthesize on the first day of sun-light. The temperature is 55 degrees and sunny and these flowers have taken a gamble to appear green and succulent on this first big show-day with expected freezing snows coming next week.

                                                                                                                            1061 (4)

 Tiny red blossoms of a witch hazel (Hamamelis x intermedia) in the North Woods, photograph taken by Ken Chaya on 2/23/14.

The groundhogs and flowers are part of an entire ecosystem’s effort in the detection and signaling of coming spring. Little is known about how plants and animals anticipate spring. Some of the most important forecasts of spring come from organisms that live in total darkness and constant climatic conditions: plants and animals that live in the subnivian zone, a layer of cavities and space between the moist warm earth below and the blanket of snow above. Winter World, by Bernt Heindrich, includes a great story of the organisms that live in this subnivian zone as well as other adaptations that animals have to winters in the Maine woods. Many organisms have internal clocks that signal when to engage in a certain activity. A famous example is a species of bamboo that occurs globally and flowers synchronously once every several hundred years. A species of Cicada, famous to New York, spends seventeen years developing underground and then emerges synchronously to mate, lay eggs and die within a few days.

The study of periodic plant and animal life cycle events and the relationship between these events and seasonality is called phenology. Some information is known about how climate change is influencing the seasonal activities of plants and animals. In New York, our growing season, the period of time where most plant growth occurs, has extended over a week. Henry David Thoreau took painstaking efforts to document the flowering dates of dozens of different plants by Walden Pond in the 1850s. Scientists have found that the same species at Walden are now blossoming between two days and two weeks earlier than they were in Thoreau’s time and that those plants that exhibit the most plasticity are surviving the best.

The impact of climate change on global biodiversity is a major crisis, and it is valuable to examine this problem on local, regional, and global levels. Young people and students across New York City, as well as myself, are getting involved in phenology as a citizen science effort to track the dates when particular species of trees first bud, when species of flowers first bloom and when monarch butterflies first arrive on their migration. These studies have important implications regarding how our climate is changing and how our flora and fauna are adapting to climate change. You may wish to learn more about phenology and if you are a teacher or a student, you may wish to get involved in citizen science here: http://www.globe.gov/web/scrc/overview

Amidst the spring flowers, I walked the North Woods with the New York Mycological Society on a search for the buried gems of this year and years past. As a group of naturalists, children and students, we found twenty species including many edibles, medicinals, and several unknowns. This is part of an ongoing effort to inventory the fungi of Central Park.

                       Gary Lincoff, mycology expedition leader, holds mushrooms found on the first day of spring, 2/22/14.

 

An Island for Beavers in a Sea of Man

Filed under: Uncategorized — jakim88 at 4:31 am on Monday, December 10, 2012

Walking by a marsh in Port Washington this spring, I found a log which tapered to a sharp tip with convex tooth markings, surrounded by aromatic wood clippings on the ground. “Beavers: Wetlands and Wildlife,” a non-for-profit organization that studies beavers, confirmed that the photograph of the evidence showed that this was indeed the work of a beaver (see the picture below, taken in August 2012, several months after the chewing was fresh).  This chew is the herald of a heroic odyssey and amazing recovery of the beaver (Castor canadensis).

            Beavers are quite adaptable and each spring the two-year-olds set off on a quest for territory. Beavers may travel over tens of miles to find good habitat. They prefer to travel waterways, probably for safety as well as speed, but may venture across land too.

            The closest known breeding beaver population is in Westchester, across the Long Island Sound. The beaver that made its way here to Port Washington probably swam from main-land New York, over seven miles away. What is more amazing, based on evidence from my Biodiversity Assessment of Port Washington, is that after making its way to the Port Washington Peninsula, the beaver climbed up hills, crossed a major road, and found a large fresh-water wetland complex where I observed the clippings. There are very few potential beaver habitats like this one because over 90% of the peninsula is developed.

            300 million beavers once inhabited a greater portion of North America. Called a “keystone species,” they transformed much of the East and Mid-West into a gigantic wetland habitat complex, a unique ecosystem that provided abundant food for a diversity of animals and for Native Americans (From Water, by Alice Outwater, 1997). The habitat was lost in the 18th century due to trapping, fur trading, and deforestation. The great demand for beaver furs in Europe helped to establish an economic base for the building of Manhattan. By the end of the 18th century, beavers were extirpated from most of North America to the remote reaches of Canada. Since then, beavers have made a comeback and have settled in wetlands throughout the rural areas of the north-east.

            The habitation of beavers in the vicinity of New York City is new, occurring within the last five years. In 2007, beavers were found for the first time in New York City, in the Bronx River, by the Bronx Zoo. In 2007, beavers were found in East Hampton, probably after their having crossed the Long Island Sound from Connecticut.              

            Is there only one beaver thus far in this habitat or are there more? Is there population viable for breeding? Can the habitat support beavers over successive populations? Are there any steps that we can take to protect, support, or enhance the habitat for these creatures?

            As a direct result of our shared history with beavers, many of them have become nocturnal and live in remote, protected places outside of human reach.  The beaver evidence I found was at the edge of one of the most remote and inaccessible places in the region. I have written a grant to the Explorer’s Club to fund expeditions to discover more about the beavers of Port Washington.

Biodiversity Assessment of the Port Washington Peninsula, New York

Filed under: Uncategorized — jakim88 at 9:06 am on Wednesday, November 21, 2012

High Resolution Habitat Map of the Port Washington Peninsula

High Resolution Wetland Habitat Map of the Port Washington Peninsula

True Color Aerial Photograph of the Port Washington Peninsula (2010)

Infrared Aerial Photograph of the Port Washington Peninsula (2004)

General Study Area Location on Long Island

I am conducting a biodiversity assessment of the Port Washington peninsula, to learn more about the area’s flora and fauna, to help protect them, and to develop opportunities for environmental education. Some of my most exciting moments have been enjoyed here after crawling underneath remote forests of thorny and poisonous plants to places where no person has visited in decades, and finding habitats such as vernal pools, gushing artesian springs, and beaver!

The habitat map that I have developed above is the first step of my
Biodiversity Assessment of the Port Washington Peninsula— a necessary step in identifying the communities of flora and fauna so that we may learn more
about them. The map also serves as a field guide for study of flora
and fauna in the forests, swamps, streams, marshes, meadows, lakes,
vernal pools, beaches, waste places, and private backyards. Encompassing fifty square kilometers, countless habitats, and hundreds of unclocked
man-hours, the habitat map is a master-piece. Copies of the map will
be made available at the local public library and science museums.

I have been conducting this work in my capacity as an
environmental analyst and field biologist with PW Green, a
non-profit organization based in Port Washington that shares a mission
consistent with this biodiversity assessment: to protect biodiversity
and provide environmental education for Port Washington and
surrounding areas. For those of you who don’t know where Port
Washington is, it is the second peninsula east of Little Neck, about
12 miles east of Flushing, Queens.

I will be presenting this biodiversity assessment as the key-note
speaker at PW Green’s annual meeting on November 27th (Tuesday at
7:30P.M. in the Hagedorn room of the Port Washington Library). In the summer of 2013 I anticipate to publish a Natural History of Port Washington.

The model for this biodiversity assessment was the habitat scheme
developed by New York State’s Department of Environmental Conservation
in concert with Hudsonia Ltd.’s Biodiversity Resources Center.
Hudsonia Ltd. is a non-profit dedicated to protecting biodiversity in
the Hudson Valley. I learned to conduct biodiversity assessments from
Hudsonia Ltd. and published a paper in 2008 on Habitat Mapping and
Remote Sensing for Rare, Endangered, and Sensitive Species in the
Hudson Valley, NY in the Journal of the Middle States Division of
American Geographers.

Using Quantum Geographic Information Systems software, the detailed
habitat map of the study area was manually “heads-up digitized,” a
process by which different habitats are overlaid on top of a
combination of aerial infrared and true color photographs, soil maps,
geology maps, and elevation contours of the study area. Historic and
recent imagery was obtained from Google Earth and used as a
reference.

My mapping includes small habitats such as wet meadows, intermittent
woodland pools, and intermittent streams. An effort is being made to
map small habitats in highly developed areas that serve as oases of
biodiversity for the surrounding community. I have become familiar
with the study area by making frequent visits with maps in hand, using
binoculars to see inaccessible habitats, and taking pictures to
document them. During the field verification phase of the biodiversity
assessment, I visited dozens of habitats of less than one acre to
greater than 250 acres in size and conducted biodiversity analysis.

Biological diversity, or biodiversity, refers to the varieties of
life forms or the web of life. It encompasses ecosystems, communities,
individual species, and the genetic variations of individual
organisms. The importance of biodiversity in the environment has come
to be widely accepted over the last three decades. Biodiversity has
been recognized as an indicator of ecosystem health, a reservoir for
agricultural variety, a source of medicines, a supporter of watershed
quality, a mediator against human disease and disease vectors, and an
aesthetic and recreational resource.

This biodiversity assessment takes a systematic and broad approach to
understanding the relationship of humans with flora and fauna within
the study area; it has many components including research, networking,
outreach and collaboration, mapping of habitats by use of aerial
photographs and other resources, and field-study of flora, fauna,
habitats, hydrology, and human interconnections.

The mosaic of a well-classified habitat map is the best tool for
describing, understanding, and predicting patterns of biodiversity.
Many questions also arise from a habitat map. A look at a habitat map
shows the distribution of habitats, their interconnections,
divisiveness and fragmentation, geography, geometry, relative rarity,
proximity to human development or disturbance, and trends that may
help predict what habitats will look like in the future.

Habitat mapping in a biodiversity assessment is followed by field
work. During field work the habitat map is ground-truthed (where
habitats that are difficult to identify remotely are visited on the
ground for verification). Many different subject matters are studied
in the field. These include understanding how geology and hydrology
affect different habitats; identifying of typical, unusual, or rare
flora and fauna; noting the diversity and prevalence of native,
non-native and invasive species; ascertaining rare species based on
knowledge of their preferred habitat types; and identifying threats to
particular habitats. Many questions arise in the field and some
habitats need to be revisited during different seasons to get a fuller
sense of their biodiversity.

In phase two of this project, the biodiversity assessment will be followed
by recommendations on environmental protection, the preparation and
presentation of pertinent reports, and recommendations for future
studies. This biodiversity assessment report should be published in
the summer of 2013.

Biodiversity assessment is a tool to help people take initiatives
that will protect the environment. Recommendations from the
biodiversity assessment are geared towards all sectors of the public,
including homeowners, businesses, environmental organizations, and the
government. A biodiversity assessment also serves as a resource for
those interested in exploring nature, discovering new places, and
learning about the geology, flora, and fauna of an area.

The study area encompasses the Port Washington peninsula north of the
Long Island Expressway and also parts of Manhasset and Roslyn,
skirting along the mouths of the Manhasset and Hempstead Harbor Bays.
The inter-municipal study area was chosen for its high degree of
biodiversity, for the great local appreciation of biodiversity and
desire for its protection, for its many diverse, under-studied, and
unknown habitats, and for geographical continuity.

 

Eyes on the Ground, Heart in the Air

Filed under: Uncategorized — jakim88 at 8:24 pm on Sunday, May 6, 2012

Who notices the wonder five feet below one’s eyes?

Golden Saxifrage (Chrysosplenium americanum), a field indicator of springs (where groundwater emerges to the surface).

“He who hopes for spring with upturned eye never sees so small a thing as Draba. He who despairs of spring with downcast eye steps on it, unknowing. He who searches for spring with his knees in the mud finds it, in abundance.” -Aldo Leopold in a Sand County Almanac (1949)

The field biologist’s dilemma:

Relax your eyes and observe the birds: soar like a hawk.

Focus your eyes and observe the ground: get mired in a quagmire.

 

 

Caterpillars on a Black Cherry Sapling

Filed under: Uncategorized — jakim88 at 11:23 pm on Wednesday, May 2, 2012

Walking through the forests of Sands Point Preserve on April 21st, I spied a silken tent pitched upon a black cherry tree sapling (Prunus serotina). The sapling stood three feet tall with a vine full of caterpillars wrapping around. Half of the leaves were eaten.

As I stopped to sketch the hairy black caterpillars with their many blue eyes and what appeared to be one head on each end against the brilliant woven silver star backdrop, I found myself crawling. I knew that some caterpillars are dangerous to the touch, and that some are not; but these caterpillars looked harmless.

I then wondered if this was one of the species of tent-caterpillar that is known to demolish hardwood forests. Conservation biologists urge “early detection, fast response.” In other words, destroy the colony before it has a chance to spread. Concerned, I called my guru in botany, Jason Rosenberg of New Paltz, and he gave me the common sense advice, “just observe them and see what you can learn from them.” Meanwhile dozens of caterpillars were trailing back and forth across the forest floor, and all over me. I kept observing as dozens of caterpillars were following linear trails, probably looking for more fresh leaves, laying down a trail of pheremones.

Doing some research, I found that there are six species of tent caterpillars in North America. This caterpillar happened to be the eastern tent caterpillar (Malacosoma americanum), and not its dangerous stinging and forest-devouring cousin, the gyspy moth (Lymantria dispar), which causes almost a billion dollars in annual damages to the U.S. Nor was it the forest tent caterpillar (Malacosoma disstria), which usually don’t kill the trees they feed upon, unless the trees are already weakened by drought.

Eastern tent caterpillars do little damage to forests; they specialize on trees of the genus Prunus, of the rose family, and these trees are found mostly in plantings of suburban and agricultural areas, with the exception of black cherry trees. Trees of the genus Prunus concentrate cyanide in their leaves as a defense, and the eastern tent caterpillars have evolved to eat the trees and detoxify by spitting out the ingested cyanide in a concentrated juice form.

Today I returned to the tent site. It was a rainy day and the caterpillars were taking a siesta on the underside of their tent. The entire black cherry sapling had been defoliated and as I looked very close, I was able to observe minute new buds where the leaves once were, marking a second spring for the black cherry.

The Inner Ant and Outer Human

Filed under: Uncategorized — jakim88 at 9:44 pm on Thursday, April 12, 2012

That love of nature is an innate human quality, is the subject of E.O. Wilson’s 1984 book, Biophilia. According to Wilson, ants (and their close relatives, bees, wasps, and termites) and humans are the only truly altruistic animals on earth. A colony of these ants is made up entirely of sisters. Because the sisters all share the same genes and do not reproduce, it is adaptive for them to work together for the health of the colony, to the death, forming the perfect society imagined in Plato’s Republic.

Ants experience the world by senses of taste and smell that are thousands of times stronger than that of humans. Humans mainly experience the world by the senses of sight and hearing, from vantage points thousands of times higher than ants. Humans have relatively poor senses of smell and taste, though these senses form the strongest memories we have. Perhaps minimal senses of smell and taste were evolutionary trade-offs; as humans evolved to eat a greater variety of foods, smell and taste were reduced to improve the palatability of otherwise offensive foods. This is similar to the case of owls, which have evolved to eat skunks; owls don’t have a sense of smell. Or perhaps as humans developed an identification system using formal names, our antecdent method of identification using senses of smell and taste fell into the background. But evidenced by our heightened memories of smells and tastes, these senses are still important.

Primitive humans used to determine the edibility of plants through an ordered series of tests: the smell test, the lick test, the bite test, the eating of a morsel test, where more and more was eaten, until the safety of the plant was determined. Then there are also children who bypass this series of tests and determine right away whether a certain plant is edible or poisonous. As a youngster, I found that the enchanting red berries of the sweet mucilaginous yew (Taxus baccata) (the poisonous seeds of which I would spit out) and the flavorless wild false strawberries (Potentilla indica), were fun to eat. Plants with pungent acrid odors are often poisonous and are naturally avoided. Some deceiving plants, like the arrow arum (Peltandra), have been dubbed “memory plants” by those unfortunate enough to chomp them. My uncle (and mentor in nature-study) once fed his family poisonous mushrooms; thankfully the family is still alive. Few plants are potent enough to kill a human upon the swallowing of a small morsel; the Destroying Angel Mushroom (Amanita) is one. Curiously, people have acquired the knowledge to use many poisonous plants and mushrooms medicinally.

I am a connoisseur of plant smells. As I walk through the forest, I pick up samples, crush them, smell them, and store them in my pockets for perfume, car decorations, future use, identification, or good luck. I can rarely be found without a plant on me. Even those plants that I have smelled many times, I like to smell again to see how they change with the seasons or how one individual’s odor varies from another. Most importantly in our modern age, plant smells are just beautiful; they are a complement to our audio-visually dominated lifestyle. Me and my nose are cross-pollinaters of flowers. As the bees die off, we will all have to stop to smell, if only to help the flowers.

The other day as I was walking through Central Park by the reservoir, I smelled a lilac bush (Syringa) from 30 meters away! As I approached it I observed two young woman admiring the smell as well and it occurred to me that having botanical knowledge is a good way to meet girls, but I will save that for a future blog.

The Fastidious Fox of Sands Point

Filed under: Uncategorized — jakim88 at 9:46 pm on Wednesday, March 21, 2012

Following fox trails of depressed vegetation, I found myself in a curling labyrinth spanning all different directions I knew not where. In his classib book Walden, Henry Thoreau once wrote about the trail of a fox: ” Now I am curious to know what had determined its graceful curvatures, its greater or lesser spaces and distinctness, and how they were coincident with the fluctuations of some mind, why they lead me two steps to the right, and then tree to the left. The frozen pond was his journal, and last night’s snow made a tabula rasa for him. The swiftest step leaves a lasting trace.”

The linear trail of a fox, putting one step in front of the other.

I heard from local field biologists that there were foxes denning in polyvinyl chloride (PVC) pipes next to the Guggenhiem castle in the Sands Point Preserve. I did not find their home, but came upon something more interesting.

There were a dozen cinder blocks line up, each with two holes. The fox had scat fastidiously in each. Clam shells, fur and bones, bittersweet berries, and other seeds illuminate the fox’s diet. Perhaps the motive is cultural.Thoreau wrote, “Sometimes I heard the foxes as they ranged over the snow-crust, in moonlight  illuminate the fox’s diet. Perhaps the motive is cultural. Thoreau wrote, “Sometimes I heard the foxes as they ranged over the snow-crust, in moonlight nights, in search of a partridge or other game, barking raggedly and demoniacally like forest dogs, as if laboring with some anxiety, or seeking expression, struggling for light and to be dogs outright and run freely in the streets; for if we take the ages into our account, may there not be a civilization going on among brutes as well as men?” Who knows, maybe the scat in the cinder blocks and the fastidiousness with which it was deposited is a sign of the foxes’ civilization.

Phenology of Flowers

Filed under: Uncategorized — jakim88 at 10:06 pm on Monday, February 27, 2012

On Wednesday February 22nd I sighted my first turtle of the year come out of hibernation, it was 57 degrees at Sands Point Preserve Lake and a red-eared slider came out on a log.

That turtle inspired me to write down my observations of the unfolding spring, day by day and petal by petal. Phenology is the study of the dates of periodic plant and animal life cycle events and how these are influenced by seasonal and interannual variations in climate. The first dates of the blooming of particular flower species shift with the weather and thus may bloom on one calendar day this year and a different calendar day the next year. But the order of the first blooms of the different flower species stays true. I remember every year over the last three years I have observed the cuckoo-flower and the corn-speedwell as the first to bloom (here I do not include those flowers that can be found blooming all year-round including such flowers as periwinkle and chickweed in winter).

As I record the dates upon which flowers first bloom I have two goals. One is to get to know the flowers by their calendar. The second is to start a long-term phenological record of blooming flowers over the years to come.  The table below includes the Common Names of the species I have observed flowering, their Latin Name, Family Name, what part of the globe they are Native to, and the date observed. Most of these plants I have observed at Queens College.

Of the dozen flowering species that I have observed this year, not one is native to our area (except maybe the dandelion.) Additionally, even though I frequent nature sanctuaries every day, every single flowering species I have observed so far this year was found in a developed area. These startling statistics are due to a variety of reasons, it may be partly because the microclimates around buildings and waste places are warmer, and partly because non-native plants are best adapted to these places (I discuss this is in the post below entitled: http://naturedave.qwriting.qc.cuny.edu/2011/09/28/regional-wild-plants-on-queens-college-campus-and-nearby-nature-preserves/)

I have been seriously studying taxonomic botany (the study of the names of plants) since the summer of 2006. Recently I have felt that the study of the names of plants is missing something without an understanding of why the plants received their names, and the history of our cultural relationships to these plants.

To celebrate the first bloom of each flower that I encounter, I will record the first names given to each of these blooms by the different cultures of mankind. The following link displays the phenologies and etymologies of all the flowering species I have observed thus far this year. Flower Phenology and Etymology Data Sheet. This list will be kept updated and by the end of the year it should include hundreds of species.

 

 

An Introduction to Sands Point Preserve and its Changing Ecosystems

Filed under: Uncategorized — jakim88 at 9:49 pm on Thursday, February 16, 2012

As a child growing up, I often visited the ice lake at Sands Point Preserve on the north shore of Long Island. The visible beauty of the lake was as a window into the wonderful mystery of the ever-invisible spirits lurking in shrouded fog. The Great Blue Heron and Green Heron lived in this mystery. These large, colorful, reclusive birds with crooked necks stand under vegetative cover, motionless, on one leg, in wait of any unlucky fish that falls under their lance. To stalk a heron, one requires similar patience: one must stand low under cover and motionless in wait of the sunlight to pierce the heron through the bush.

Sands Point Preserve is a 216 acre preserve in Port Washington with a great lawn, forests, honeysuckle dominated shrub-forests, a sea shore, sand cliffs, and a lake. The lake of almost an acre was built at the turn of the last century to provide water for cattle and to harvest ice in winter. The elliptically shaped lake is circled by trails on every side.

Last year, a dense layer of vegetation was cut down and now almost the entire east side and much of the north side of the lake are exposed to human traffic. In the place of this cutting, a pioneering crop of invasive species formed monocultures, especially the sprawling vine mile-a-minute (Persicaria perfoliata). I became concerned about these invasive species, and two other local ecologists, Herb Mills and Seth Erlich, voiced similar concerns.

I have developed a scientific study to see whatever birds may visit the lake, particularly Great Blue and Green Herons. Starting January 14th, 2012, I have walked around the lake almost every day, frequently twice a day, to observe and record the birds I hear or see.

Beginning this study provided sustenance for a new chapter of nature discovery in my life. Returning to a place every day and making observations on the flora, fauna, and aquatic ecosystem raises many questions. There is an ever-flowing fire hydrant, but where does the water come from and where does it go? (Later this spring I am going to study the chemistry of the water that flows out of this hydrant and into the lake.) Who walked on the lake last night? What do the birds eat and of what sing? What flowers bloom today? Where do the fox footprints lead? Who cut down the trees? Questions recycle anew on a daily basis.

On my visits to the lake I have observed something unexpected. Sitting at this newly cut meadow on a cold cloudy January day, I see an aggregate of birds fill the sky above in the form of a turbulent stream of White-Throated Sparrows, Cedar Waxwings, Goldfinches and Cardinals. The newly cut meadow on the southeast side of the lake has the highest diversity, abundance, and frequency of bird visitors. Now I am uncertain whether this change was for good or for bad.

To get academic credit for a study to determine if herons no longer visit the lake, I consulted my adviser Dr. Chabora, a specialist in ecology. He advised me that my study, to determine if herons no longer visit the lake, is called a null hypothesis, and that it has no water to wade in, because I have no baseline study of past heron activity on the lake. Dr. Chabora said that “one could just as well say that there are no barracudas in the lake.” He then suggested that I proceed reading the greatest classics in the literature of natural history and to read them “for their beauty”: White’s 1789 Natural History of Selbourne, Thoreau’s 1854 Walden, and Aldo Leopold’s 1949 A Sand County Almanac. Next week we decided that I should write an inspired Natural History of Sands Point Preserve in the same vein.

In addition to this work on the Natural History of Sands Point Preserve, I am continuing a baseline study of the birds that visit the lake and surrounding habitats every day. My goal is to guide future management of the lake, if I can find the voice to optimally balance human and wildlife needs. Attached hereis my record of observations regarding species seen and associated data on their locations, habits, dates, times, weather conditions and lake conditions: Record of Observed Birds, Sands Point Preserve.

Today I found out why the trees around the lake have been cut. The ecosystem of the lake is in the process of being turned inside out. My future blog will take this new direction. All in the next installment.
Thank you for reading,

David Jakim

Colors of December

Filed under: Uncategorized — jakim88 at 11:46 pm on Thursday, December 8, 2011

 

Plants Picked on December 1st, Central Park (Click to enlarge)

New England has the most beautiful fall colors in the world. Autumnal changes in leaf color are brought on by the decay of the dominant pigment chlorophyll, which allows other hidden colors in the leaf to come out. The different pigments have interesting medicinal and chemical properties.

            Oaks have brown tannins, used in tanning leathers. Red anthocyanins are one of the healthy components of red wine; blue anthocyanins of blueberries; carotenes of carrots; betacyanins of beets.

              Senescence is the process by which cell components and membranes die. Abscission is the process by which leaves fall. The exact cause of chlorophyll breakdown is not known, and nobody really knows what brings on senescence or abscission either; one hypothesis is that they are brought on  by hormones. Other factors may include gradual reduction in day length, lowering temperatures, light intensities, or lack of water. In my next post, I will discuss my interview with a climatologist about changing weather patterns and the potential effects on plant internal clock cycles.

 

 

 

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