Why Do Trees Grow Better in Certain Locations?

The type of vegetation that grows in an area is dependent on the precipitation, temperature, and soil type that is found in that location. Puerto Rico’s temperature does not vary much (60-90F) due to the sea breezes it encounters. In San Juan, there is a lot of precipitation (68 inches annually) and, therefore, a lot of fast growing trees. Furthermore, hurricanes are a lot more frequent here than in California or Maine. In terms of soils, San Juan has very acidic soils. The acidity is both due to the leaching that occurs as a result of heavy rainfall as well as fertilizing practices by humans (Miller et al. 2009).

Sugar Maples (Acer saccharum) are deciduous, broadleaf trees that do well in the eastern United States due to the alignment of proper temperature and moisture levels needed for growth. To germinate, a samara needs specific conditions of cold temperatures (1-5°) and very moist conditions for an extended amount of time in order to advance through its dormancy (Dumbroff et al. 1978). One way to look at how well certain seeds may suit a geographical transportation is through provenance studies. A team of researchers performed one of these studies and found that seeds native to the northern part of the east coast tend to do better when placed in other parts of the east coast compared to seeds native to other parts of the east coast (McCarragher et al. 2011). However, climate change studies have shown that sugar maples are expected to become extinct as temperatures continue to rise due to the sugar maple being a cold-adapted species as well as the possibility of a restriction in carbon assimilation rates of the seedlings (Peltier et al. 2015). Though sugar maples are equipped to survive in shaded environments, they are known for having a sensitivity for climate and soil changes. Sugar maples usually grow in soils in the 5.5-7.3 pH levels but show more variation in the northern part of the United States (Social Indicators 1990).

Redwoods from California, an evergreen, coniferous tree, needs other requirements. Redwood seeds are able to germinate quickly as long as moist soil and humid air are present (Noss 1999). They are able to do so even with a high surface temperature and poor soil composition. Due to this versatility, Redwoods can grow in many locations, however, they are only able to grow to remarkable heights in the northwestern United States due to the fog (Burgess et al. 2004). Being a coniferous tree, Redwoods are able to take in small amounts of water consistently in the presence of fog which is important due to the difficulty in transporting water throughout such tall trees. Moisture is important to Redwoods and therefore either need a lot of rainfall and grow shorter or a lot of mist and fog if they are able to grow tall.

References
Burgess, S. S. O., and T. E. Dawson. “The Contribution of Fog to the Water Relations of Sequoia Sempervirens (D. Don): Foliar Uptake and Prevention of Dehydration.” Plant, Cell & Environment 27, no. 8 (August 1, 2004): 1023–34. https://doi.org/10.1111/j.1365-3040.2004.01207.x.

Dumbroff, E. B., and D. P. Webb. “Physiological Characteristics of Sugar Maple and Implications for Successful Planting.” The Forestry Chronicle 54, no. 2 (April 1978): 92–95. https://doi.org/10.5558/tfc54092-2.

McCarragher, Shannon R., David Goldblum, and Lesley S. Rigg. “Geographic Variation of Germination, Growth, and Mortality in Sugar Maple (Acer Saccharum): Common Garden and Reciprocal Dispersal Experiments.” Physical Geography 32, no. 1 (January 1, 2011): 1–21. https://doi.org/10.2747/0272-3646.32.1.1.

Miller, G., and A.E. Lugo. “Guide to the Ecological Systems of Puerto Rico.” San Juan, PR: U.S. Department of Agriculture, Forest Service, International Institute of Tropical Forestry, 2009. https://doi.org/10.2737/IITF-GTR-35.

Noss, Reed F. The Redwood Forest: History, Ecology, and Conservation of the Coast Redwoods. Island Press, 1999.

Nowacki, Gregory J., and Marc D. Abrams. “Is Climate an Important Driver of Post-European Vegetation Change in the Eastern United States?” Global Change Biology 21, no. 1 (January 2015): 314–34. https://doi.org/10.1111/gcb.12663.

Peltier, D. M. P., and I. Ibanez. “Patterns and Variability in Seedling Carbon Assimilation: Implications for Tree Recruitment under Climate Change.” Tree Physiology 35, no. 1 (January 1, 2015): 71–85. https://doi.org/10.1093/treephys/tpu103.

Social Indicators. Department of Commerce, Bureau of the Census, Center for Demographic Studies., 1990.