FOREST CARBON SEQUESTRATION LAB: Write-up due THURSDAY 7 NOVEMBER

I. GET THE DATA: 
        - downloading an excel spreadsheet here, you can work directly in excel if you prefer
        - OR, if you want to work in google sheets,  download the excel file, then: 1) in your google drive click 'new' and 'upload', 2) choose the excel file to upload or drag the file to the upload window (depending on interface you find)  

II. ANALYSIS
    - We will review/talk about spreadsheet functions in lab.  Building on this, use the formulas provided in the spreadsheet to
        * Estimate total aboveground biomass of all trees for the two permanent forest study plots ('maple' and 'pine'; each is on a separate tab in the spreadsheet).
        * Convert these values into some sort of useful "biomass density" unit (kg/ha is a good one; estimates are in kg; plots are 500 square m; ha = 10,000 square m) for each plot. (NOTE that these are 'dry biomass' estimates -- organic matter without water).
        * Calculate CHANGES in biomass between measurement years, and convert to estimate of RATE of NET CHANGE IN aboveground biomass (this is a component of the ecosystem's net primary production, or NPP; we'll talk about this later). Put this in terms of a rate of change in biomass density (e.g. kg/ha/yr) for each plot for each of the study intervals between measurement dates and overall (for the full 15 years).  
        * To answer questions below, you will need to convert biomass or NPP values to values for CARBON contained (since biomass is not all carbon); dry biomass is about 40% carbon.

III WRITE-UP (what you will submit, along with 'worked' spreadsheet). FORMAT is up to you, but should be clearly structured and should include at least the following:
    - A narrative that summarizes the purpose of the analysis and gives a description of the results obtained (estimates of biomass densities and NPP, and how they've changed over time) in a reasonable format.  If you are feeling ambitious, you could describe results/trends for some particular species as well as overall.
    -You SHOULD INCORPORATE GRAPHS (or refer to graphs included in your spreadsheet).  You don't need to give lots of numbers in the narrative -- just summary numbers and descriptions of patterns -- but the quantitative results should be clear from graphs.  This should be a few paragraphs -- a page or two -- without graphs.
    - Following your narrative report you should give specific answers to the following questions:
        1. Are these forests CARBON SINKS (accumulating biomass and so extracting C from the atmosphere on average) or SOURCES (decreasing in biomass and so adding C to atmosphere)? 
        2. Assess MAGNITUDE of carbon sink or source: for ONE of the stands,
                a) estimate the total amount of C being taken from or added to the atmosphere for a an area of similar forest comparable in size to whole campus (approximately 450 acres; look up conversion from ha to acre on google; a hectare is larger than an acre; make sure your conversion goes in the right direction!), and
                b) the amount of gasoline that, when burnt, would yield a comparable amount of carbon.  A quick internet search should tell you how much C is added to the atmosphere for each gallon of gasoline burned (make sure it's C and not carbon dioxide mass), and calculate the 'gasoline equivalent' of the change in standing biomass per year (either per ha, or for an area the size of campus)?
        3. What are most interesting similarities and/or differences between the stands? Offer one hypothesis for why they might differ in observed trends (you may consider what you know or think likely about the history and nature of the two stands; remember that the pine stand is a planted forest -- a plantation -- that is around 50 years old, with some other species now growing among the pines; the maple stand is much older and 'naturally' regenerated, as we talked about in the field).
        4. Note that we are considering only LIVING, ABOVEGROUND biomass of TREES here.  What are some other potentially significant reservoirs of carbon in these forests that you'd want to look at if you wanted a really complete measurement of the carbon dynamics of these forests?  How might you undertake measuring the amount of carbon involved and how it is changing (don't need a lot of detail on this; a paragraph or so)?  

TURN IN YOUR SPREADSHEET AND DISCUSSION/ANSWERS DIGITALLY.  You can either email me the documents/spreadsheets OR share them as google docs/sheets.