EEMB/ES 171Problem Set #1Due: October 28, 2019 1. You are studying the effects of climate change on community ecology of ecosystems in central California. You collect the data in Table 1 for a site in the Sierra Foothills. The vegetation is dominated by chaparral and coastal sage. The rains start in the late fall and normally end by the end of April.Table 1. Climate data.SeasonAverageTemp. (° C)Rainfall(mm/season)K forcalculating PETFall 25 125 1.3Winter 5 425 1.0Spring 20 260 1.25Summer 35 60 1.4Use the following equation to calculate PET: PET (mm/season) = 3* (15 + (TEMP)K)K is a constant that depends on the season and is in the tableabove. Note: this is not the real formula. I came up with it as asimple equation that predicts plausible numbers. The realequations are complex and depend on latitude. Assume that the ecosystem can store a total of 100 mm of water in the soil. That means that the first rain that falls will go to satisfying PET. The next 100 mm will be stored in the soil and will be available for plant use in the following season and will be included in AET for that season. Any rainfall beyond that in a season will run off in stream flow. A. Calculate the water balance for each season. Start with a “water year” that begins with the fall. Assume no water is stored in the soil at the end of the summer. Provide estimates of PET, AET, and stream flow. Also calculate the total annual budget by summing up your seasonal estimates.Rain PET AET Soil Storage Stream Flow Fall 125 241.98 125 0 0Winter 425 60 425 100 365Spring 260 (+ 100) 171.88 260 100 88.12Summer 60 (+ 100) 480.32 60 0 0Fall PET: 3 * (15 + (25)^1.3)Winter PET: 3 * (15 + (5)^1.0)Spring PET: 3 * (15 + (20)^1.25)Summer PET: 3 * (15 + (35)^1.4)Winter Stream Flow: 425 – 60 – 100 Spring Soil Storage (Capped at 100mm): 260 – 171.88 + 100 Annual Rain: 870Annual PET: 954.18Annual AET: 870Annual Soil Storage: 200Annual Stream Flow: 453.12B. Describe the moisture conditions for plant growth in each season: Do you expect plants to be actively growing? Merely surviving? Why?In the fall, the plants will be merely surviving due to how there is a water deficit, AET < PET. This shortage of water means the plants will be under drought stress. In the winter the plants will be actively growing due to how the AET satisfies the PET and there is moisture stored in the soil. However, it is important to consider how the extreme stream flow could cause erosion events to occur which would prevent the plants from growing to their prime. In the spring the plants will beactively growing due to how AET satisfies PET and there is still water stored in the soil. The concern of water stress isn’t as severe in the spring due to how the stream flow is not excessive. In the summer the plants will be merely surviving due to how the AET does not satisfy the PET and therefore they will be under drought stress. C. Using the biome figure above, what type of biome do you think this would be described as? How sensitive do you think it would be to climate change?Average Annual Temperature: (25 + 5 + 20 + 35)/4 = 21.25 degrees CelsiusAverage Annual Rainfall: (125 + 425 + 260 + 60)/4 = 217.5 mm = 21.75cmBased on the chart above and the values calculated, the biome studied is most likely a desert. Due to how the average annual temperature is located towards the center of the desert section, it is notsensitive to changes in temperature. The average annual rainfall is also located centrally in the desert section meaning it is also not sensitive to shifts in precipitation. However, due to how the section is so narrow, the ecosystem is more vulnerable to changes in precipitation than other biomes which is due to how deserts are often dry and underdeveloped making it so they cannot take up large amounts of water. D. You are also studying productivity. So, you model annual net primary productivity (NPP) in this ecosystem. The equation for the global relationship between NPP and AET for each season is:NPP (g•m-2y-1 aboveground) = 1765 * Log (AET+25) - 3400What would you predict annual NPP to be? Fall NPP: 1765 * Log (125 + 25) – 3400 = 440.80Winter NPP: 1765 * Log (425 + 25) – 3400 = 1282.92Spring NPP: 1765 * Log (260 + 25) – 3400 = 932.80Summer NPP: 1765 * Log (60 + 25) – 3400 = 5.42Annual NPP: 2661.94E. Now assume that you actually go out and measure NPP. You get a value of 1200 g•m-2y-1 aboveground. In case you didn’t get the correct answer from part D, this is below the estimated value. Give three reasons why the actual could be lower than the predicted. Your reasons should be based in the biological/ecological controls on productivity, not in something like “the model is wrong”. Then describe, briefly, how you might determine which explanation(s) is correct?Reason 1: The limiting resource is not water but another mineral or component of growth. For example, if the plants are getting more nitrogen than what is a normal amount, we could measure the nitrogen levels over a span of time and then add a large supply across the environment and monitor if significant increases in growth follow. This would give an indication of whether there is a different limiting resource. Reason 2: There could be an invasive species that disrupts the functioning of the system. The invasive species could out-compete native species for resources such as light. If this invasive species was removed from areas compared to a “control” area of the same ecosystem, the differences in NPP could be due to the invasive species. Reason 3: There could climate changes which lead to a varying degree of precipitation. These shifts in climate can be due to temperature changes as a result of global warming. If the temperature was to rise, there could be more evapotranspiration, leading to a higher PET and lower AET. If there is lessprecipitation, then the PET cannot be satisfied and ultimately lower NPP. This can be studied by looking at historical temperature and precipitation data and comparing it to corresponding changes in NPP. G. Now calculate soil respiration for each season and for the year as a whole. The model for soil respiration is:Soil respiration = (M + 5) * e(0.075*T)M = the average amount of moisture stored in the soil over the season (M at beginning + M at the end)/2), not just the moisture at the end.T = air temperature for the seasonNote that the temperature term is an exponential equation (e to the power 0.075 *T). Fall soil respiration: (0