In this experiment, we observed and analyzed the disease called Sudden Oak Death ( SOD ) . Sudden Oak Death is a soundless efficient slayer of trees in coastal California. It is distributing out fast killing legion species of Oak and Tanoak in California, particularly in Sonoma County. The chief species that is most effected by SOD is Umbellularia californica, ( ) . Harmonizing to California Oak Mortality Task force ( COMTF ) , this disease was “ foremost reported killing trees in Santa Cruz and Marin states in mid-1990s ” . Now it is distributing out in “ 14 cardinal and northern coastal counties in California: Humboldt, Mendocino, Lake, Sonoma, Napa, Solano, Marin, Contra Costa, Alameda, San Francisco, San Mateo, Santa Clara, Santa Cruz, and Monterey ” ( COMTF ) . Among these county Sonoma County is confronting tonss of job sing SOD. Many oak trees are deceasing and tonss of trees has already died. Harmonizing to US forest aerial study, the map allotment of SOD shows presently “ 7.5 % of the land in Sonoma Country ( 75,000 estates ) has been affected by SOD mortality in merely past three old ages ” ( ) . Due to this Sonoma Country has been a major country for new SOD infestations and mortality. Sonoma County has “ twice every bit many estates affected by SOD mortality than any other county in California ” ( ) . Since, Sonoma County has higher rate of SOD mortality, it has been a large menace to Sonoma Country. Its menace can hold major impact in environment, ecosystem and economic sciences. The immense figure of dead and deceasing trees can effects the occupants of county in assorted ways. The dead trees can fall in the roadways, house, power line etc. This can do many jeopardies including hurts, decease or belongings amendss. Death trees can go through disease to other trees and infect them. Oak and tanoak tree are the beginning of acorns, which are the nutrient for different wild home grounds. When big sum of oak and tanoak trees are dead, there will be a loss of nutrient for those home grounds. Trees are the beginning for dirt strength and stableness, so when there are tonss of dead tree dirt will lose it strength. As a consequence, good dirt could pass over out from the land. Fire functionaries says the dead trees are the chief cause for wildfire and increasing dead trees in Sonoma county put the county at a high hazard for inordinate fire behaviour ( ) . This full possible jeopardy could do a batch for this county economically and environmentally. To halt the spread of disease many research workers are making researching sing the pathogen that cause Sudden Oak Death. Even though research worker are non to the full able to understand how the pathogens spread out. Therefore, it is necessary to analyze on this job to work out the unreciprocated inquiries.

Correspondingly, our chief ground of the experiment was besides to analyse how those diseases spread in a tree, so we can be able to reply the unreciprocated inquiry. To get down the experiment we should foremost cognize the pathogen that causes SOD. Sudden Oak Death is cause by works pathogens Phytophthora ramorum ( California Oak Mortality Task Force ) . Phytophthora ramorum is a microscopic being. This species are H2O cast so it requires warm and wet conditions to bring forth. California coastal woods are evergreen, dodo and moist, which are the perfect clime for Phytophthora ramorum. Predator P.ramorum is largely impacting the ‘California bay laurel ‘ . In a host tree, it develops hyphae, which grow through bark and leaf tissue. It is produce sexually and asexually. Asexual generative constructions called spore case and chlamydospores. Sporangia release zoospores, which have two scourge that propel them through H2O. Chlamydospores are strong constructions that protect the pathogen during hostile conditions, such as heat and drouth ( ) . For sexual reproduction Phytophthora ramorum needs different coupling type ( A1 and A2 ) . In California, type A2 coupling is found and sexual reproduction has non been studied much outside the research lab ( oak decease ) . As nonsexual reproduction is more studied and known, so we should larn it for farther survey. Sporangia can distribute through air and infect works tissue by direct contact. Zoospores have flagella so it can swim through H2O. Rainwater or sprinkling H2O can distribute the Zoospores to other works. They besides stay feasible in dirt and infect works tissue. Chlamydospores can populate in hostile status so it can digest for sometime without any host. This spores spread through non merely weave, rainwater, works stuff, but besides human activity. In moisture season, human moisture places can reassign the septic spores to other works. When spores are spread on other trees foliages and bole it causes works to a fatal infection. In this manner pathogen spread over a broad country doing a serious infections on trees that leads to a sudden decease. With all these cognition, we are making our ain hypothesis for our experiment. First, we created a sensible inquiry ; Are sun leaves more susceptible to infection than shadiness foliages? Harmonizing to the inquiry, our hypothesis was that Sun foliages are more susceptible based on old category experiment. To prove/falsify our hypothesis we create an experiment infecting 10 Sun foliages and 10 shadiness foliages from each tree. After infecting, we let it to develop the infection and subsequently analyse it comparing frequence and magnitude of infection. This gave us the informations and the consequence for our experiment.

Methods and meterials

To prove our hypothesis we set up an experiment in three parts. In first portion, we collect the foliages, in 2nd portion, we infect the foliages, and in 3rd portion, we analyze the septic foliages. We collect our foliages in California laurel modesty. Pepperwood modesty is located at southland of the northern coastal scope. It lied between Sonoma and Napa County. It is stretch toward North of Calistoga to east and Santa Rosa to west. Across the Papperwood modesty there is a bird’s-eye position of Papperwood modesty covers 3000 estates zone of attention-getting landscape and comfortable biodiversity ( ) . It varies in lift from 240 to 1,560 pess, which create an ecological diverseness ( ) . Papperwood modesty is an intermediate clime zone where mean temperature is about 60. Due to its ecological diverseness and intermediate clime there are broad diverse of home ground. Papperwood modesty preserve mixed evergreen forest, unrecorded oak tree, tan oak-redwood wood, grassland, and chaparral ( ) . There are assorted species of birds, reptilians and amphibious vehicles, and mammals in California laurel modesty. Before we collect our foliages, we took a brief tree description such as species name, figure of short pantss, perimeter bole, and the tallness. To roll up our informations and foliages, teacher provided us a needed instrument such as measuring tape, cutter, and wrapper bag to maintain leave. Our group tree has six short pantss with different perimeter. Below is the mensural perimeter.

Number of Trunk








Average tallness of our tree was 20 pess. To mensurate the tallness we merely use one of our friend highs and compare it with the tree to come close tallness of the tree. After we took a tree description, we cut the 10 Sun foliages and 10 shadiness foliages for the experiment. The procedure to cut the foliages was rather diverting. The tip leaves of the subdivision were a new foliages but for the experiment, we need last season foliages. Last season leaves has good develop metamorphosis so it would be best for pathogen to respond. To divide the new foliages from old we feel the bud like surface in the subdivision. Beyond the bud surface was the foliages we need for the experiment. From Sun and shade side of the tree we cut the subdivisions that had good foliages on it, and kept inside the negligee bag. After cutting foliages, we observed the surrounding and marked the topographic point for farther way. Around our foliages, there were many grasses named Festuca California. In forepart of our tree, there was besides dead fallen tree and oak sprout. All this information will assist us to follow our tree for following visit. The gathered foliages were brought to the lab. In the lab, we observed the foliages size, raggedness and smoothness. Size of the foliages were same for both Sun and shadiness foliages. Sun foliages were small thicker, curved and unsmooth, where shadiness foliages were thinner, flatter and clutter. After observation we choose 12 good Sun foliages and 12 good shadiness foliages. For both Sun and shadiness ; 10 foliages were labeled 1 through 10 and other two were label C1 and C2 with tape and marker. Labeled foliages were cleaned with intoxicant and cotton balls. After cleansing by intoxicants, all the foliages were cleaned with deionized H2O. Meanwhile when foliages were drying we set up two boxes in the tabular array for leave to lie on. In each box, we labeled our group figure, day of the month and either Sun or shadiness. In both box we put a half inch of unfertile vermiculite. This helps to absorb the humid environment inside the box. After completing the box apparatus, we put dry foliages level in the box confronting lower side up: 1 through 10 foliages lie in a row across the box, and C1 and C2 lie on the side of the other 10 foliages. After seting foliages in the box, we infected our foliages with micropipet. In 1 through 10 foliages we infected it with p.ramorum zoospores and for control we put dirt and H2O. After infecting foliages for both Sun and shadiness, we put box palpebra on tightly and kept it in appropriate topographic point.


Shade foliages

Sun foliages

I ) Our Group Data for SOD experiment

Tree 4













Average magnitude





II ) Summary informations for category SOD experiment









Tree 1







Tree 2







Tree 3







Tree 4







Tree 5







Tree 6







Tree 7









Table ( I ) is our group informations for SOD experiment. The average magnitude of Sun and shadiness gives the p-value for our informations. Table ( II ) concludes all category mean informations of both Sun and shadiness. Calculating the norm of each group mean magnitude gives average informations for whole category. The deliberate category mean provides a new p-value. In the drumhead informations for category tree 4 represents our group average magnitude.


Harmonizing to our group consequence, the p-value is high. Our group p-value is 0.4836. There is 48 % chance that the difference in magnitude between Sun and shadiness is due to random events. Higher the p-value Tells there is no grounds that our hypothesis is true. This means that there is no significance difference between the average magnitude of infection on Sun and shadiness foliages. Our informations concludes that both Sun and shadiness foliages were infects in equal magnitude. Therefore, it falsify our hypothesis that Sun leaves infect more than shadiness foliages. Now comparing to others informations, our average value is lower, because our foliages have less magnitude of infection. This is likely due to an experimental mistake. While we were infecting the foliages, some beads of zoospores might steal out of the foliages or some beads may steal while traveling the box. This could hold been due to swerve foliages. Harmonizing to my personal observation, there were some curve foliages and we were holding difficult clip puting the zoospores at the right topographic point. Due to this, we could likely acquire less infection in magnitude. Other ground could be due to improper sum of vermiculite, which could consequence in the environment of pathogens. If there is more vermiculite than there might non be plenty humid that pathogen demands to turn, or if there is less vermiculite than there might be more humid, that pathogen can non turn plenty. Comparing our category group and other category group, our group has less magnitude of infection. This is likely due to the temperature and the environment. The twenty-four hours we went to roll up foliages was dazed and the twenty-four hours other category went to roll up foliages was cheery. In cheery twenty-four hours, tree foliages will acquire more energy from sunlight through photosynthesis than in a dazed twenty-four hours. Due to greater energy, their foliages metamorphosis rate might hold been higher than our foliages. Therefore, when foliages were infected, pathogens might hold better environment to cultivate in the foliages that were metabolically active. However, looking all categories ‘ informations the average magnitude is still high. Therefore, this lab experiment falsify that the Sun leaves does non infected more than shadow one. Harmonizing to the consequence, the magnitude infection was comparatively same without any significance.

The experiment conclude that the hypothesis we created were non good plenty to cognize the manner pathogen infects in trees. Our whole experiment was non good plenty because the ground might be that the Sun visible radiation does non ever come in the same way. The foliages of the tree are non necessary to confront the Sun every clip and the shadiness foliages are non ever be in shade systematically. In a twenty-four hours period, at a different clip, sunshine will equally administer. Therefore, every side of foliages will hold similar sum of visible radiation. As a consequence, they will hold similar metabolic rate. Therefore, this might do that we get the similar magnitude of infection on both Sun and shadiness.

Our group did non roll up more good foliages so while fixing leaves we did non hold more pick, so we have to utilize curve foliages. While pipeting it was difficult to set beads of zoospores in the foliages due curve, as a consequence some of the beads were stealing. Particularly me, while pipeting I was non keeping the pipet straight vertically so some of beads were excessively little due to air bubble inside the pipet. All this mistake can better in following experiment, so we possibly will acquire good consequence.

For following experiment a different thoughts should be usage for a good consequence. After looking this experiment, the consequence turns out hapless for our group. There was non much infection in foliages. I think this is due to miss of moister environment for pathogens. Based on research, Phytophthora ramorum loves wet and damp environment. Therefore, for following experiment we could do moister environment for pathogen, so it can infect leaves out more expeditiously. To do a humid status we can set less vermiculite in our boxes so it can non absorb humidness. In add-on, we can set some H2O in vermiculite to give a moister environment. As I mentioned above that the shadiness leaves besides gets similar sum of visible radiation as Sun foliages. Therefore, for our following experiment we can travel to our tree and cover the shade leaves with black plastic for while so the visible radiation can non go through through it. After roll uping the foliages, we can set shade foliages in black plastic and Sun foliages in regular plastic black. This creates that shadiness foliages will non acquire plenty light to do energy and will be metabolically slow. Therefore, making such environment we can foretell that Sun leaves will be more septic than shadiness foliages.

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