McLucas_B_lab6_dendroclimatology_lab_report
docx
keyboard_arrow_up
School
Appalachian State University *
*We aren’t endorsed by this school
Course
1011
Subject
Geography
Date
Feb 20, 2024
Type
docx
Pages
6
Uploaded by brandonlee4me4
GHY 1011 – Global Climate Change
Dendroclimatology
Part I (use this file Lab6_dendroclimatology_lab_report.docx to compose your lab report. Before submitting the report via the submission portal for Lab 6, rename the file using our standard convention, McLucas_B_lab6_dendroclimatology_lab_report.docx )
1.
Where does alpine larch grow? (1 point)
Larch trees have a 250-year lifespan. The interior Pacific Northwest (Montana, Idaho, Oregon, and Washington) of the United States and British Columbia, Canada, is home to both western larch (Larix occidentalis) and subalpine larch (Larix lyalli). Since they have needles instead of leaves and produce their seeds in cones, they are conifer trees, like pines. 2.
Alpine larch is a conifer (i.e., it has needles for leaves) with a unique characteristic. What is it? (1 point Wladimir Köppen, a German-Russian climatologist, classified a region's climate as humid continental in 1900. With warm to hot and often humid summers and arctic, occasionally very cold winters, it is distinguished by four distinct seasons and notable seasonal temperature variations. Although precipitation is usually distributed throughout the year, there may be multiple dry seasons.
3.
What is the oldest alpine larch to be found to date? (1 point)
1538 is the oldest. 4. The Köppen
climate type at the study site is Dsb. Describe that climate type, using online resources such as Wikipedia https://en.wikipedia.org/wiki/Humid_continental_climate
(3 points)
This climate is defined by the following temperature ranges: at least four months with mean temperatures at or above 10 °C (50 °F) and the coldest month's mean temperature having to be below 0 °C (32.0 °F) or −3 °C (26.6 °F) depending on the isotherm [/2]. The area in question also can't be completely dry or semi-
arid. Hemi boreal climates are another name for the colder Dfb, Dwb, and Dsb subtypes.
5.
What climatic elements does the PDSI include? (2 points) PDSI is computed using soil's local Available Water Content (AWC), temperature, and precipitation data. Each of the fundamental terms of the water balance equation, such as evapotranspiration, runoff, soil recharge, and moisture loss from the surface layer, can be found from the inputs.
6.
What does it tell us about conditions in a particular area? (2 points)
It tells us that it gets really cold around 10C, 0C and -3C
7.
What is one limitation of the PDSI that might be pertinent to Montana? (1 point) Disadvantages of the PDSI are that it is slow to detect quick-onset droughts, and does not reflect snowpack, an important component of water supply in the western United States. 8.
Describe (~50-100 words) how PDSI and tree growth trend alongside one another during the instrumental record period (1895-2015) in this area of Montana. ( 2points)
Eastern Washington of the Columbia Plateau (WA8) and northern Montana of the northern Glaciated Plains Palmer Drought Severity Index (PDSI) between 1895 and 2015 (MT3). A score of 3.0 or lower indicated a severe drought. 9.
Examine Column “C” in the “correlation matrix” tab on the spreadsheet and discuss (~50-100 words) the statistical evidence supporting what you described in your answer for question 8. (4 points)
10.
Scroll to the intersection of row 48 (June-August temperature) and column AE (June-August precipitation) in the “correlation matrix” tab. What is the r-value of this this correlation? (1 point)
JJA_Temp
Pearson Correlation
.435
.303
0.115
.282
0.117
.214
.624
.625 .644
11.
The strength and direction (negative) of the r-value between JJA temperature and JJA precipitation should suggest something to you about the relationship you discovered between the PDSI and alpine larch tree growth. What is it? (discuss - ~50-100 words) (4 points) the relationship between the PDSI and the alpine larch tree growth is a strong relationship with the precipitation and the temperature.
Part II
12. What is the strongest (best) relationship for growth vs. temperature, for growth vs. precipitation, for growth vs. PDSI? Write these down along with the associated r-value and p-value. Remember that
r-values that are closest to +1 and -1 are strongest. Provide your answers in a list. (3 points)
The strongest relationship for growth vs. temperature is -0.40, with an r-value of -0.40 and a p-value of 0.004.
The strongest relationship for growth vs. precipitation is 0.23, with an r-value of 0.23 and a p-value of 0.008.
The strongest relationship for growth vs. PDSI is 0.21, with an r-value of 0.21 and a p-value of 0.012.
13.Among all climate variables considered, what are the top 5 strongest (best) relationships? Write these down along with the associated r-value and p-value. (5 points)
1961 p value 62.3 r value 4.81 1945 p value 58.4 r value 2.32
1940 p value 60.73 r value 5.39 1931 p value 60.13 r value 1.1 1933 p value 59.6 r value 2.93
14. Based on your answer to Question 13, discuss (~50-100 words) what aspects of climate are important for growth of this tree species (4 points). What’s most important for the growth of these tree species is a very abundant source of water with a good amount of mouths with a lot of precipitation.
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help
15. The “regression” tab in the spreadsheet shows the results of the regression analysis between JJA_temp and annual radial growth of alpine larch. The results provide us with the numbers to construct
our mathematical model that takes the generic form: climate = a + (b * tree growth). The yellow highlighted number for the constant is “a” in the formula, and the value from growth is “b”). Write out the full mathematical form of the model (be sure to replace the generic “climate” with the descriptive name of the climate variable). (2 points)
Another way you could right it would be c = a+(b*d)
16. What were the 5 warmest summers between 1538 and 2015, based on the reconstructed climate record? List those years and the associated growth values. (*note – you can use the sort feature in Excel
to make this task easy, as described in the narrated instructions) (5 points)
1. 1998- Growth: 3.305, Predicted X-Value: 6.1757
2. 1997- Growth: 2.9, Predicted X-Value: 5.1231
3. 1702-Growth: 2.536, Predicted X-Value: 4.1771
4. 1885-Growth: 2.502, Predicted X-Value: 4.0887
5. 1965- Growth: 2.441, Predicted X-Value: 3.9301
17. What were the five coldest years between 1538 and 2015 based on the reconstructed climate record? List those years and the associated growth values. (5 points)
1. 1632- Growth: .037, Predicted X-Value: -2.31784
2. 1657- Growth: .037, Predicted X-Value: -2.31784
3. 1788- Growth: .037, Predicted X-Value: -2.31784
4. 1794- Growth: .037, Predicted X-Value: -2.31784
5. 1931- Growth: .037, Predicted X-Value: -2.31784
18.
In Excel, create a line graph showing the temporal pattern of JJA (mean of June-August) temperatures
over the 478 year period. Include a copy of this graph in your report. (5 points)
19. Examine the graph and discuss the temporal patterns or trends that you see. (~50-100 words) (4 points) the patterns that I start to notice is the p values and the r values fluxgates once the year moves up the temperatures seem to stay at a higher steady pace around the high 50s, low 60s in the 1920s.
Part III 20.
Discuss (~100 words) how Dr. Knapp used dendroclimatology and PDSI values to examine the climatic conditions during the Corps of Discovery expedition. (5 points) 21.
Were Lewis and Clark lucky or unlucky with regard to the climate along the expedition route from 1804-1806? Discuss (~50-100 words) (5 points) Yes they were pretty lucky during the spring and summer months the rain was really high and in the fall and winter months the winters were long and cold so it depended on the month but also depended on their luck.
22.
What would severe drought have meant for the success of the expedition? Discuss (~50-100 words) (3 points) It wouldn’t of been good for the success of the expedition because these people in the expedition need water and so does the plants so that they can do their research there is a severe drought it could ruin some chances at good data but I think it would be okay because of these times of drought they could test a tree and see how long it can hold water for in a serious drought.
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help