Definition of tropical

[Zeeth]

What do you guys think the definition of tropical is? Mean temps above 64 for each month in the year, or by looking at vegetation? It is certainly easier to do so by vegetation, like saying if coconuts and other tropicals will be full term in an area. Temperature readings from the internet are often skewed, as many times what you are reading for one city is often from a station in another, often colder, city. I would bet that certain areas of costal St. Pete, Anna Maria Island, and some of the other islands in the area do indeed have mean temps above 64 for the entire year, but since stations are usually based on the mainland the readings are skewed. A good example of this is that the station for Longboat Key is likely based in east Sarasota, as the temperature readings are colder than Brandon's, but there are coconut palms a plenty, and some long term Pritchardia pacifica in the warmer spots. What is your opinion on which method is best to say whether your area is tropical or subtropical?

[spockvr6]

What is your opinion on which method is best to say whether your area is tropical or subtropical?

If its 23 degrees latitude or less, its tropical!

[Zeeth]

What is your opinion on which method is best to say whether your area is tropical or subtropical?

If its 23 degrees latitude or less, its tropical!

Well, being within the tropic of cancer and capricorn certainly helps, but those 2 lines are only the boundaries of where the sun is directly overhead at noon during some time in the year. Some cities, such as Hong Kong, are within this boundary, but have recorded freezing temperatures, where cities, like Key West, that are not in this boundary, have not. Therefore I don't think a straight line all across the globe is sufficient to say what the climate will be like, nor does it determine that you are not a certain climate, even if you fit all the other standards.

[spockvr6]

What is your opinion on which method is best to say whether your area is tropical or subtropical?

If its 23 degrees latitude or less, its tropical!

Well, being within the tropic of cancer and capricorn certainly helps, but those 2 lines are only the boundaries of where the sun is directly overhead at noon during some time in the year. Some cities, such as Hong Kong, are within this boundary, but have recorded freezing temperatures, where cities, like Key West, that are not in this boundary, have not. Therefore I don't think a straight line all across the globe is sufficient to say what the climate will be like, nor does it determine that you are not a certain climate, even if you fit all the other standards.

Yeah.....we have discussed this on the board before and there is never a solid answer. We just go in circles all day So, this is why I posted what I did There are so many ways in which to define tropical. I take the approach of looking at the globe and looking at where the lines fall rather than use a temperature measurement, as this makes the situation very hard to define and the lines dont fall so neatly as they do if we just look at the map Basically......does tropical mean climate or does it mean within the geographical tropics? The first one is easy to define the second is alot harder.

[bubba]

Tropical=one hand clapping, grasshopper

[amazondk]

Zeeth,

I have to agree with Larry. I believe you have to define tropical as within lines on the globe. And, that temperature has nothing to do with the fact that a given location is tropical or not. Quito, Ecuador is on the equator at about 9,000 feet above sea level. It gets relatively cold there. But, it just as much in the tropics as Manaus where I live. Vegeatation is something different from latitude. Now if you define things by average temperatures it would be hard to find somewhere more tropical than where I live.

Average temperatures, Manaus, Amazonas, Brazil

Quito, Ecuador.

[siafu]

What do you guys think the definition of tropical is? Mean temps above 64 for each month in the year, or by looking at vegetation?

From Wikipedia, the free encyclopedia

A tropical climate is a kind of climate typical in the tropics. Köppen's widely-recognized scheme of climate classification defines it as a non-arid climate in which all twelve months have mean temperatures above 18 °C (64 °F).

[amazondk]

I still consider all climate zones in the tropics to be tropical. That means that mountains with snow are tropical mountains with snow. Of course the climate and vegetation changes with altitude. What Zeeth asked is what is considered tropical. The island of Hawaii is a great example of many climate zones in the tropics. If the temperature gets under 20 C here people go into thermal shock and die.

dk

[Palm Guy]

In addition to all months averaging above 64 F, another factor to consider is that the temperature difference during the day (ie day time highs and lows) must be greater than the seasonal temperature difference (ie average daily high temperature at summer's peak vs average daily low temperature at winter's peak)

Bermuda averages above 64F all year round but I wouldn't consider it tropical as winter temperatures are quite distinct from summer. Its definitely subtropical.

[Zeeth]

Alright good, getting some discussion going on here!

So basically "tropical climate" is a word that is used to describe a warm climate, which says that the temperature relates to generally what is seen for climates within the tropics. Therefore, tropical climate can have many definitions, the mean low of above 64F for all months being one of them, vegetation being another one, but no matter what, if it's a zone 12 at 24 degrees latitude, it still isn't within the tropics, where a zone 7 at 22 degrees latitude that is inland and at a super high altitude with yearly snow is still tropical. This is odd, when you look at how the 2 lines for the tropics were drawn, being a place that the sun is directly overhead at least once yearly. These lines move with the tilting of the earth. The tilt in the earth's axis changes (very minimally, but it changes nonetheless) so these lines may move at times.

[amazondk]

Keith,

There are various definitions of tropical. But, from a strictly geographical perspecitve it has to do with latitude not altitude. And, that does not have anything to do with climate. Now if you are talking about climate than it is a different subject and has to do with temperature and even percipation possibly.

And, the only constant in life is change. Especially when talking about climate. Here on the equator one thing I can verify is that it is never cold at my altitude of 90 feet above sea level.

dk

[Zeeth]

Keith,

There are various definitions of tropical. But, from a strictly geographical perspecitve it has to do with latitude not altitude. And, that does not have anything to do with climate. Now if you are talking about climate than it is a different subject and has to do with temperature and even percipation possibly.

And, the only constant in life is change. Especially when talking about climate.

dk

I did mean climate wise, but there are definitely 2 completely different ways to talk about tropics. I tend to think that it's better to talk about it climate wise.

[amazondk]

Keith,

I think there is a difference between those of us who live in the tropics and those who do not. Whether ones view is better than the other or not is simply a matter of definition. Climate is one thing, latitude is another. At the snow line in the Andes is not the same as in the Rocky Mountains. One is in the tropics and the other is not. And, there is a big difference.

dk

[Paul The Palm Doctor!]

I don't care about the classification of my piece of land either here in So. Fla. or in Panama (on the western Caribbean Coast near Costa Rica.) I just know what plants I wish to grow, and I pretty much can tell where they'll be successful. My ULTRA-tropical Artocarpus altilis thrives in Panama, and just hangs on here (and hasn't yet fruited) in South Florida. Breadfruit is a USDA Zone 12 plant to be sure. My Cyrtostachys renda doesn't do well in So Fla. either. It is a Zone 11 palm. Both of those plants grow like weeds in Panama, of course, without any attention.

I live at 26 degtees North latitude in southern Florida (and the nights are cooling to the lower 60's now on average, while Panama has no appreciable temperature change any month (at 9.2 degrees North latitude.) It's tropical in the Changuinola, Bocas del Toro area, without question. Extreme South Florida is "about the best we can do" on the mainland of the U.S. in growth of tender vegetation...BUT every so often, a major arctic pool of air will nail us but good; then the weather result is anything BUT semi-tropical. It looks like crap everywhere you look, but then you get a string of 60 days of 84+ F, max. and 63+ F. minimums, and BAM, you're quickly back into beautiful foliage and flowering, again. Easy as that!!

Stats and rules of classification are excellent guidelines for planning & planting a landscapebut plants cannot read. Marginal plants will die, at times, if pushed too far out of their "comfort Zones." You will never really know in what particular winter freeze carnage will occur, but realise that it WILL OCCUR! (Besides, I love planting over again , as long as the $$$ holds out!)

Paul, The Dr.

[epicure3]

My definition of tropical would be a climate where there is a 0% chance of 32F all 365 days.

[Zeeth]

My definition of tropical would be a climate where there is a 0% chance of 32F all 365 days.

That would be good by some standards. Key West fits this definition.

[Paul The Palm Doctor!]

My definition of tropical would be a climate where there is a 0% chance of 32F all 365 days.

Oh, boy, Epi!

I don't know if all tropical plants would fare too well at anywhere near 0 degrees C. I think that "de facto tropical" would mean a place that the temperatures never dip below 50 F. or (10 C.)

Plants that aren't subjected to under 50 F. look tropically healthy, and aren't yellowed or leaf spotted by any cold. The plants know what's tropical & will live rebustly and multiply freely.

Again, these are only definitions that are convenient for OUR classification. Dr. Paul

[aussiearoids]

The tropics is a place you can sling a hammock between two clumps of Lipstick palms , and relax in the shade of an enormous fruiting breadfruit sipping a mangosteen margarita from your own tree.

[Paul The Palm Doctor!]

That works for me, Michael! None of those particular trees would thrive in anything less than a "true tropical" temperature environment!

Paul

[amazondk]

My definition of tropical would be a climate where there is a 0% chance of 32F all 365 days.

Where I live there is a nearly zero percent chance of the temperature going below 70 F all 365 days of the year. And, if it does it may reach 68 F.

Maybe it is because Homo Sapiens evolved in the tropics there is always an subconcious urge to be somewhere warm and lush. During the last glacial maximum when Florida was a barren sand dune covered desert with frequent cold western Amazonia was still basically the same as it is today.

So, I do not plan on moving during the next ice age.

dk

[Paul The Palm Doctor!]

I can understand why, Don! If I don't tell you by week's end for some reason, I'll wish you now a "Happy 2010!" Let's hope that there is just a bit more serenity worldwide, than there has been in 2009!

Paul

PS: Don, could you put a post or two over in my www.thewisegardener.com project? You are so interesting that the readers there "soak up" your posts like a sponge!

[siafu]

My definition of tropical would be a climate where there is a 0% chance of 32F all 365 days.

Does your fridge qualify then?

There are many relatively cool places that do not have tropical climates and never experience below freezing conditions.

The Azores Islands and Lord Howe Island come to mind, for instance.

First and foremost, a tropical climate needs to be hot.

[Paul The Palm Doctor!]

My definition of tropical would be a climate where there is a 0% chance of 32F all 365 days.

Does your fridge qualify then?

There are many relatively cool places that do not have tropical climates and never experience below freezing conditions.

The Azores Islands and Lord Howe Island come to mind, for instance.

First and foremost, a tropical climate needs to be hot.

I would think that would be most important.

Paul

[PalmGuyWC]

I've always heard that a tropical climate is where Coconuts grow.

Dick

[Zeeth]

I've always heard that a tropical climate is where Coconuts grow.

Dick

That's usually what I use for measure... There are some places that don't get cold enough to damage them, but there isn't enough heat, which would make it not tropical though. How about not just grow, but grow and fruit properly enough for natural regeneration, and aren't damaged by the cold yearly. This excludes places where they may grow for a while, but in freezes like in '89 they die. If this method is used, West bradenton Bradenton, parts of St. Pete, Anna Maria island etc. are included in this definition of "tropical", which makes sense, because the level where coconuts are able to survive is also followed by a number of very tropical looking plants, such as the Banyan ficuses.

[amazondk]

This is my definition of Tropical.

A lazy Saturday afternoon watching the boats go by at my place on the Negro River. The only non tropical place around is the cooler where the beer is stored.

[Zeeth]

This is my definition of Tropical.

A lazy Saturday afternoon watching the boats go by at my place on the Negro River. The only non tropical place around is the cooler where the beer is stored.

Don, what is your all time lowest temperature? I'm sure that since you are about 3 degrees away from the equator that the differences between seasons aren't any more different than daily differences.

[Palm Guy]

I've always heard that a tropical climate is where Coconuts grow.

Dick

That's usually what I use for measure... There are some places that don't get cold enough to damage them, but there isn't enough heat, which would make it not tropical though. How about not just grow, but grow and fruit properly enough for natural regeneration, and aren't damaged by the cold yearly. This excludes places where they may grow for a while, but in freezes like in '89 they die. If this method is used, West bradenton Bradenton, parts of St. Pete, Anna Maria island etc. are included in this definition of "tropical", which makes sense, because the level where coconuts are able to survive is also followed by a number of very tropical looking plants, such as the Banyan ficuses.

Well coconuts are probably one of the better indicators however, there are so many factors which determine their fruit set other than temperature. For example, Coconuts can be grown in the Dominican Rep however, not on every locale of the country. There are desert/dry islands which are home to Pseudophoenix ekmanii where temperatures would be sufficient but I'm assuming rainfall/humidity would not. Also, you have to factor in soil depth, water table etc and even then it may just come down to genetics.

For example, here in Bermuda, Adonidia, Dictyosperma, Hyophorbe, Pritchardia, Veitchia all set viable seed and look good here because of one factor, their generally resistant to potassium deficiency which is very common on shallow alkaline soils (the average depth of soil here is probably between 4-8'' then you hit pure limestone). They do slow down in winter somewhat, but it has no affect on fruit set and all of them will establish freely if planted in wooded areas. Phoenix Dacytlifera, the 'edible date palm' grows and is even consdidered a weed here (like any other phoenix palms) however, the dates do not mature properly, possibly due to potassium deficiency or some other factor. Remember potassium is critical for palm health and fruit set and even in the tropics a coconut can die or not set seed properly!

The coconut can self sow in Bermuda and has done so quite often which is contrary to what most think, but it occurs mainly on beaches where the soil/sand is deeper and more easily penetrable for coco's roots . You do not see them growing wildly because its a small country where most people remove the fallen coconuts so it cannot establish natural colonies. The fruit may not always be as large as you would find in the tropics however, even that varies from tree to tree. I've seen normal sized coconuts and some pretty pathetic looking ones off the trees here. Typically, younger trees set better fruits. I think its mainly because the larger, older trees have difficulty pulling up nutrients to the crown.

See pictures below. Notice that the smaller cocos tend to have larger fuller crowns versus taller cocos. A crown that is 'shrinking' is typical of potassium deficiency. Also, see pic of a small tree carrying quite a bit of fruit. That tree is the smallest of the lot.

The ones about 300 ft away are looking much better perhaps to better soil, so its not necessarily due to temperatures alone.

Cyrtostachys would be a good 'tropical' indicator temperature wise however, it would need to be in high rainfall areas to grow naturally, it would basically croak if you rogue planted one in Pseudophoenix territory without additional irrigation. That's why I do not think plants alone can be an indicator for a tropical climate, there are soo many other factors. Remember there is Tropical monsoonal, Tropical Wet/dry, Tropical Savanah, Cool Tropics etc, each with its own set of plants to match!

[amazondk]

Keith,

The all time low temperature that I could manage to find was 63 F. But, I have never seen it that cold in the 10 years I have lived here. Nor in the 20 years I have been coming here a lot. It does get frequently over 100 F in the dry season some years. The rainy season is when the temperatures are the lowest at daytime running from 88 to 93 F.

dk

[Zeeth]

Keith,

The all time low temperature that I could manage to find was 63 F. But, I have never seen it that cold in the 10 years I have lived here. Nor in the 20 years I have been coming here a lot. It does get frequently over 100 F in the dry season some years. The rainy season is when the temperatures are the lowest at daytime running from 88 to 93 F.

dk

Wow, that's pretty interesting. I thought that there was no marked dry/wet season within 5 degrees of the equator though maybe it's because you are more inland?

[amazondk]

Keith,

I believe that marked seasons as to precipitation are quite common around the world in the equatorial tropics. I have posted climate data in other threads which shows this. Our dry season normally runs from July through October. This year it was drier than normal and the rains started later. This was an impact of the El Niño that set in during the second half of the year. The first half of the year was wetter than normal due to the La Niña that was in effect. Due to the rainy season being in our summer months this period is known as winter here even though it technically is not. Summer here is any period with little rain. The main impact of being 5 degrees from the equator is that there are no hurricanes. Of course I am a long way from the ocean so they would never get here anyway.

dk

[Zeeth]

Keith,

I believe that marked seasons as to precipitation are quite common around the world in the equatorial tropics. I have posted climate data in other threads which shows this. Our dry season normally runs from July through October. This year it was drier than normal and the rains started later. This was an impact of the El Niño that set in during the second half of the year. The first half of the year was wetter than normal due to the La Niña that was in effect. Due to the rainy season being in our summer months this period is known as winter here even though it technically is not. Summer here is any period with little rain. The main impact of being 5 degrees from the equator is that there are no hurricanes. Of course I am a long way from the ocean so they would never get here anyway.

dk

Hmm, quite interesting. Is the climate any different closer to the ocean? Here, proximity to the ocean is key. A few miles inland can mean the difference in an entire USDA zone.

[spockvr6]

Yeah.....we have discussed this on the board before and there is never a solid answer. We just go in circles all day

See? Told ya! LOL

[Zeeth]

Yeah.....we have discussed this on the board before and there is never a solid answer. We just go in circles all day

See? Told ya! LOL

As long as no one is being rude and it's all in good fun then that's a good thing!

[SunnyFl]

Yeah.....we have discussed this on the board before and there is never a solid answer. We just go in circles all day

See? Told ya! LOL

I'll tell ya where tropical is NOT. That would be HERE.

brrrrr.

[amazondk]

Well life moves in cycles and circles anyway.

Keith,

Yes at least in Brazil the rainfall at my latitude in Amazonia is more evenly spread throughout the year than here over by the coast near the delta of the Amazon. I am about 1,500 miles from the ocean by the way. All the weather in Brazil is affected by Amazonia. I guess you could equate it sort to the impact the Gulf of Mexico has the weather in the USA to a large degree. Although Amazonia is roughly 60 per cent of the land mass of the country. And, Brazil is larger than the continental USA.

dk

[Zeeth]

Well life moves in cycles and circles anyway.

Keith,

Yes at least in Brazil the rainfall at my latitude in Amazonia is more evenly spread throughout the year than here. I am about 1,500 miles from the ocean by the way. All the weather in Brazil is affected by Amazonia. I guess you could equate it sort to the impact the Gulf of Mexico has the weather in the USA to a large degree. Although Amazonia is roughly 60 per cent of the land mass of the country. And, Brazil is larget than the continental USA.

dk

That's very interesting, thanks for the info!

[bgl]

Looking at "tropical" strictly from a climate point of view (as opposed to the geographical definition), the question is really very simple: can someone, over an extended period of time, grow just about any trooical palm (or plant, if you want to be really inclusive)? If the answer is 'yes', then the climate in that location is obviously tropical. Average temperatures mean nothing if a freeze can happen - even if only very rarely.

[spockvr6]

Keith,

There are various definitions of tropical. But, from a strictly geographical perspecitve it has to do with latitude not altitude. And, that does not have anything to do with climate. Now if you are talking about climate than it is a different subject and has to do with temperature and even percipation possibly.

And, the only constant in life is change. Especially when talking about climate.

dk

I did mean climate wise, but there are definitely 2 completely different ways to talk about tropics. I tend to think that it's better to talk about it climate wise.

To look at it that way, I would think a very simple way to think of someplace as being "tropical", in the traditionally thought of sense of what "tropical" means to the average Joe----

Could one plan a trip there, with intents of spending time at the beach, without regard to looking at a calendar?

[spockvr6]

Yeah.....we have discussed this on the board before and there is never a solid answer. We just go in circles all day

See? Told ya! LOL

I'll tell ya where tropical is NOT. That would be HERE.

brrrrr.

Aint that the truth! What a nasty couple of days weve had. Not terribly cold at night, but the thermometer hardly moves up during the day.