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Inputs/Outputs Inputs Hourly Environmental Weather File Outputs
Hourly Environmental Weather File ECOPHYS reads in weather from a file each day. Contained in this file are measurements of
Two site conditions are needed to run ECOPHYS - Soil Reflectance and Latitude. Both are needed for light interception.
Bud-Break Date - Currently ECOPHYS has a user-inputted bud-break date entered for each year of growth. Further investigation of a dynamic bud break date based on temperature or soil temperature will be studied more in the future. Bud-Set Date - This is a fixed date which determines when the main terminal and any other branches that are still growing will set their buds. Each branch on the tree is capable of setting it's buds earlier in the growing season if it's stressed. Leaf Senescence Start Date - The date when leaves on the simulated tree will begin to drop at the end of the growing season. Leaf Senescence Rate - This is the rate at which the leaves will fall off of the tree at the end of the growing season. Determination of when a leaf drops is based it's LPI, not on how many leaves are on the branch. Initation Rate - The number of hours before a new leaf will emerge on branches that have not set their buds yet. This is currently a fixed number, but we are investgating a more dynamic approach. Leaf Death Threshold ( τL ) - A measure of leaf starvation. If a leaf is not producing enough photosynthate above this level, it will die based on the scaling factor. (Roskoski's Thesis) Leaf Death Scaling Factor( δL ) - A scaling factor affeting the likelihood that a starving leaf will die. (Roskoski's Thesis) Bud Set Threshold ( τb ) - A measure of branch starvation. If a branch is not producing enough photosynthate above this level, it will set it's buds and stop growing in length based on a scaling factor. It will then focus it's extra photosynthate on maintenance. (Roskoski's Thesis) Bud Set Scaling Factor( δb ) - A scaling factor affeting the likelihood that a starving branch will set it's buds. (Roskoski's Thesis) Branch Death Threshold ( τB ) - A measure of branch starvation. If a branch is not producing enough photosynthate above this level, and it has already set it's buds, it will then die based on the scaling factor. (Roskoski's Thesis) Branch Death Scaling Factor( δB ) - A scaling factor affeting the likelihood that a starving branch will die. (Roskoski's Thesis) Internode Specific Gravity - The specific gravity of an internode is a comparison of its density to that of water. (Roskoski's Thesis) Ratio of Leaf Width to Leaf Length Growth Respiration Ratio - The Growth Respiration Ratio is a ratio of the amount of photosynthate used for respiration when new plant material is being synthesized.. Maintenance Respiration Rate - Maintenance Respiration is that which is used to keep existing tissue alive, functioning, and healthy. The rate is based on the internode's cambium layer. Initial Expanding Leaf Zone Specific Leaf Area (SLA) - The SLA in the beginning of the growing season Final Expanding Leaf Zone Specific Leaf Area (SLA) - The SLA at the end of the growing season Photosynthate to Biomass Factor - This factor is used to convert photosynthate into biomass. Overwinter Storage to the Top Internode - The percentage of overwinter storage allocated to the end internode of each branch before distribution of storage in the beginning of a growing season. The remaining storage is then distributed to the rest of the new shoots based on the internode's previous year's leaf productivity. ECOPHYS has a daily output file which includes Leaf Count, Leaf Area, Stem Height, Trunk Diameter, Leaf Dry Weight, Stem Dry Weight, Dry Weight Sum, Photosynthate to Roots, Root Length, and Dead Leaf Mass.
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