There are several sources of information you can use to find the mean annual temperature and precipitation values for your site. The following are a few suggestions:

• You can find all 3 basic NPP model inputs (temperature, precipitation and biome) from a gridded database of worldwide locations available on the GLOBE Carbon Cycle web site. You enter your latitude and longitude. There is also information there about how to find the latitude and longitude of your town on the internet. Or you can use a GPS to get your latitude and longitude. The worldwide data base is located at globecarboncycle.unh.edu/GlobalBiomassModel.shtml (or from the GLOBE Carbon Cycle home page globecarboncycle.unh.edu , you can navigate to the Activities tab and then to Modeling and then on to the Global Biomass Model page).
• From a nearby weather station you can get 30 year average annual temperature in degrees C and total annual rainfall in millimeters. Sometimes this information is given in inches of preciptation and degrees Fahrenheit. You can convert by these formulas:
  C = (5/9)*(F-32)
  mm = 25.4*inches
• Temperature and precipitation and other climate variables can be accessed through the web sites of several climate data networks. A few examples are:
  U.S. National Climate Data Center www.ncdc.noaa.gov
  World Meteorological Organization www.wmo.org
  United Nations Food and Agricultural Organization www.fao.org
  In addition to climate data, these sites contain a great deal of other interesting information about the world we live in.
• From a long-term weather record of your own data if your site has had a weather station operating for 10 years or more.

You will also need to find a reasonable turnover rate for your location. The turnover rate is the rate at which living plant material dies and becomes plant litter (dead leaves, wood, roots, etc. which later become incorporated into soils). This is usually determined as the ratio of the amount of dead plant litter produced in a given year to the total amount of plant biomass present (the standing stock or pool size of plant biomass). In some cases, plants only live for one year or less (plants known as annuals). For these plants, their entire biomass dies each year, so the turnover rate is 1. In other words, 100% of their total biomass turns over each year. For plants that live more than a year - called perennials, the turnover rate will usually be some number between 0 and 1. For example, for many grasses, the above-ground portion of the plants die each year, but the roots can persist from one year to the next. Hence, the turnover rate for grasslands might be closer to 0.5, meaning that 50% of total biomass dies each year. For much larger and longer-lived plants like trees (some of which can live for hundreds or even thousands of years!), plant litter produced each year [twigs and branches that die and fall to the ground] is often a small fraction of the total biomass. The turnover rate in forests can be as low as 0.02 (2 % of standing live biomass dies each year). Finally, in many cases, the amount of dead plant litter produced each year is approximately equal to the amount of new plant biomass that is grown. This often occurs when an ecosystem has matured and is no longer accumulating biomass, such as in an old-growth forest. In these cases, the turnover rate can be estimated using the growth rate divided into the total biomass because this will yield the same number as the death rate divided into the total biomass In order to complete this exercise, youÕll need to know the turnover rate for the your own site. There are several ways you can find this information:

You may have your own data if your school has been measuring biomass and litterfall on a nearby plot.
• You may be able to find something about a turnover rate from a local researcher for the type of vegetation you have.
• Within the model there is a table provide which gives average turnover rates for the major world biomes (note that these are only averages and may differ somewhat from the true value at your site).
If you do not know your biome, you have a few options:
• Use the latitude, longitude lookup from above.
• Check out the descriptions put out by the World Wildlife Fund: http://www.panda.org/about_wwf/where_we_are/ecoregions/ecoregion_list/index.cfm
• See the protocols for determining your biome given in the GLOBE Seasons and Biomes project: http://www.globe.gov/fsl/html/templ.cgi?biome_desc&lang=en&nav=1

Worksheet A - Basic Exploration with the model
With these runs, you will look at the output graphs and tables and read off values for different variables and, based on your understanding of the input, and output flows and the stock - biomass, try to explain the values for the Biomass, the litter, and the NPP when there is no climate change setting for TempIncr nor DeltaPrecip.