This morning as I pedaled across campus in barely above freezing temperatures with a strong wind in my face I was reminded of late autumn in Chicago. Except the sun was shining. As nothing else has appeared, here's a brief bucket on the weather.
The Daily Bucket is a regular feature of the Backyard Science group. It is a place to note any observations you have made of the world around you. Rain, sun, wind...insects, birds, flowers...meteorites, rocks...seasonal changes...all are worthy additions to the bucket. Please let us know what is going on around you in a comment. Include, as close as is comfortable for you, where you are located. Each note is a record that we can refer to in the future as we try to understand the patterns that are quietly unwinding around us.
Here on the Daily Bucket we are charged with the study of phenology - which is the science of seasonal occurrences. When are flowers blooming, birds arriving and leaving, leaves appearing in the spring, and so on.
Indirectly we are also looking at this over the broad geographic scale of North America as we all live in different places with different climates. As I just finished lecturing about this it is convenient (and appropriate on this chilly day) to discuss variation in climate and habitat both generally and more specifically right here in Florida.
Below is a map of the average rainfall in florida for the period 1961-1990. Sorry about the weird pixillation - it isn't present on the original image and it happened both times I uploaded it. As it doesn't obscure any part of the map I stopped messing with it. It shows that average precipitation is highest in the panhandle and in southeastern Florida with the driest areas in the central peninsula and in patches in the central peninsular Gulf coast and central to northern Atlantic coast. Other maps from different time periods show a similar pattern.
Unfortunately I wasn't able to find a nice summary temperature map so I had to make do with the map below which shows average minimum temperature. In a minute you will see that, while this is very handy for gardeners, it isn't the best indication of the organisms that you will find living in the wild.
Below is a fairly famous diagram showing the Holdridge Life Zones. In 1967 Holdridge published this scheme of habitats based on temperature and precipitation. It is kind of confusing. Basically you go from hot at the bottom to cold at the top and the right hand side of the triangle is precipitation. The combination of those two things determines the humidity province at the bottom. The humidity plus temperature then determines the Potential Evapotranspiration rate on the left side of the triangle. The PET is basically a measure of the degree to which water is limiting in that environment.
Below is a somewhat less complicated way of depicting the same thing. Showing the crude climate space for each biome. This is a lot easier to read than Holdridge but it shares the problem of oversimplification. Note that the chaparral biome completely overlaps several other biomes. The reason for this is that annual precipitation and temperature do not capture all of the complexities of the climate. In particular they have left out seasonality - or the distribution of temperature and moisture over the year. Chaparral is a biome marked by a particular seasonality in rainfall - with almost all the rain falling in the winter and extremely dry summers.
Below is the average monthly rainfall for the Florida panhandle where I live. Rainfall is high, over 60 inches a year in Tallahassee. There is some seasonality with the middle part of the fall and spring being dry but both summer and winter are fairly wet.
In contrast below are the seasonal rainfall patterns for far southern Florida (immediately below) and the southern half of central Florida (up to about Tampa). Both show a much more seasonal pattern of rainfall with wet summers and fairly dry winters.
I don't have temperature graphs but the temperature seasonality would show the opposite pattern. July temperatures would be fairly similar throughout the state but January temperatures would vary markedly as shown on the second map at the top.
So southern Florida can be described as a seasonal tropical environment with relatively modest variation in temperature but with a distinct wet and dry season while north Florida has an essentially (warm) temperate pattern with fairly moist summers and winters but a much larger seasonal variation in temperature. Not surprisingly the habitats of north Florida resemble those of the rest of the southeastern United States while (some of) those of far southern Florida resemble habitats in the Caribbean.
Of course this is still a crude description of the relationship of climate to habitat as it doesn't take into account things like soil type, local topography, and other factors such as the flow of water to produce the everglades.
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