Station 15: Douglas Fir Stand
Did you notice a change in the vegetation upon arriving at this station? This is typical of a Douglas-fir forest stand. Obviously, there has been a change in environmental factors that favors Douglas-fir. What major factor is different? This site is more moist and the soil is deeper so it can hold more water. Also, its exposure is not as directly south as the areas you were just in. There is less sunlight and wind here, so there is less evaporation. Also, since Douglas-firs have become established and they grow in a more dense stand than ponderosa pine, the area is more shaded. This makes it cooler, further reducing the amount of sunlight and slowing evaporation. What can you tell about plant succession on this site and what is the site’s probable climax plant species? There are both ponderosa pine and Douglas-fir here. However, notice that the larger, older trees are pines and the younger, more abundant trees are Douglas-fir. Do you see any pine seedlings? Probably not, since ponderosa pine do not reproduce well in shaded areas. Notice that the shade also limits the amount of understory vegetation. Douglas-fir is the climax tree species here.