Sunday, March 17, 2013

Vegetation communities as a guide to scenery

Many parts of the United States have relatively uniform communities of natural vegetation which extend for miles. Even some mountainous areas exhibit consistent vegetation over a wide region. But as in so many other ways, California is different. In numerous parts of the state, distinct vegetation communities thrive in close proximity, often due in large part to microclimates, which in turn can be a dominant influence in Mediterranean climates like California’s. Understanding these considerations is of obvious importance in creating realistic layout scenery.
     As with other posts I have written, I recognize that the specifics of what I discuss here applies to my layout and few others. What I hope to demonstrate is an approach to learning about and applying knowledge of landscapes.
     An epiphany moment for my understanding of this topic, as a native Californian and one who has lived in the state for many years, was reading Elna Bakker’s book, An Island Called California, 2nd Edition (University of California Press, 1984). She describes with knowledgeable enthusiasm the many variations in vegetation communities (and the ecological consequences of them) which can be found in California. I had been seeing much of this landscape for years without understanding what I saw, and again and again, I would read a section of the book exclaiming to myself, “yes, of course, I’ve seen exactly that.”
     I will just give a couple of examples that apply to my layout. The most familiar California landscape probably is the oak woodland, meaning grasslands with scattered oak trees, usually valley oaks (quercus lobata, the largest of America’s oaks) but sometimes live oaks (such as the coastal live oak, quercus agrifolia). The area I model contains some areas of oak woodland, such this example near Santa Maria.


In hilly areas, the oaks (and some accompanying chaparral) tend to concentrate near stream beds and lower areas where water availability is greater. This results in a distinctive landscape also, with drier slopes mostly grassland.


Most of the importance of knowing how these communities look is for my layout backdrops, which attempt to reproduce these kinds of appearance.
     Near the ocean, outside the immediate beach area, many parts of California exhibit “coastal sage,” a community which often looks like brushy chaparral but comprises smaller plants, and different ones. Here is an example of this landscape, near the area I model. You can see the ocean in the left background, and the SP main line in the middle distance.


In this case, the vegetation is summer brown (photo taken in September), but the same area would be a dark green in spring when rainfall has been occurring.
     I have attempted to model this community on my layout, at the end of the peninsula above the beach scene. It’s shown in one of my posts about layout fascia, available at: http://modelingthesp.blogspot.com/2013/02/layout-fascia-my-approach.html .
     California’s wild grasses have a seasonal progression which often confuses people from other places. The grasses have to sprout new growth whenever rain starts, so the hillsides and fields start to green up in late November or early December, which is a typical time for the rainy season to start. Then rains will arrive irregularly through about the end of March or mid-April, and grasses remain green throughout that time and of course increase gradually in height. Then once rain is no longer arriving, the grasses go dormant and begin to turn straw color (often called “golden” by the romantically inclined), and by late summer, more of a pale brown color. Both the second and third photos in this post show that late-season brownish color.
     But in amongst most grassy areas are annual weeds of other kinds, some of which can remain green all summer. So although entire hillsides of uniformly colored grass certainly exist, local areas may be more mixed. This photo of a bank just north of the depot in San Luis Obispo, taken in August 1981, shows what I mean.


The grass here is not exceptionally high (nor is it on most hillsides), so despite the understandable enthusiasm of some modelers of midwestern and other seasonal grasses, to use very tall electrostatic grass in natural areas, that is really not very typical of California.
     This discussion of California seasonal grass, like that on vegetation communities, obviously only applies for modelers recreating that specific vegetation community. But I expanded on it to illustrate that one needs to understand what is going on in the landscapes you model.
Tony Thompson

1 comment:

  1. I had an interesting question about this post, via e-mail, asking how a person might find information about vegetation communities in other areas, and if there are other books like Elna Bakker's book. I can't answer the second part, but I suspect that if you Google, for example, "vegetation communities western Kentucky," you will get leads toward answers.
    Tony Thompson

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