Growing altitude

[Paph_LdyMacBeth]

Something I`ve run into often, but seldom thought deeply about is growing altitude of orchids. Whenever I research a particular species of any orchid you always come across this information. While I understand what it means I don`t fully understand how to use this information in my culture.

Internet research has yielded poor explanations.
Is this important, and how do I interpret it?

Cheers

 

[Ross]

One general truth for climates is the higher the altitude, the cooler the temps, especially at night.

 

[NYEric]

Yep, the lower the altitude the warmer the plant grows, at least for tropical new world plants.

 

[Shiva]

Which explains why you have snow capped mountains in the tropics. The higher you go, the thinner the air. Less air means less retention of heat at night especially. At high altitude, you may go from summer to winter and back to summer again in a space of a few hours during daylight. All it takes is a few clouds to change season. Definitely not where I would want to live.

 

[Kavanaru]

but you need to be carefull, not to directly compare with same altitude in temperate climates... 1000 m above sea level in the tropics is still (generall) a bit warm (you could hardly have a Cymbidium re-blooming or a cold growing Masdevallia doing well) while in Switzerland you almost always have snow!

A general thumb rule, is one Celsius Degree less per 100 m that you go up the mountains in the tropics... Of course you have some other factor afecting this, and you can have at the same latitude, cool weather and warm weather at 1000 m...

but the general rules is as mentionned: the higher the cooler...

 

[Shiva]

There are significant differences between altitude and latitudes.
In the tropics, the sun shines 12 hours a day all year long. Plants and orchids have adapted to different altitudes because the light, temperature, humidity and rainfall are generally constant, only varying in degrees or percentage with altitude all the way to the snow line.

As you go up or down in latidudes North or South, the day length vary tremendously and the rotation of the Earth gives rise to the coriolis effect that transfers some of the heat of the tropics North or South. The coriolis effect is what gives hurricanes their typical shape.

As these storms come into the landmasses, they break apart and continue northward and eastward with the rotation of the Earth. In winter, plants shut down with the diminishing light and without enough sunshine, temperatures go down. In this case, sunshine, temperature, humidity and type of precipitations vary enormously. Again, plants had to adapt to this situation but in different ways than those in the tropics.

I hope I didn't bore you with this post. :snore:

Michel

 

[Ray]

I summarized it like this in an article on "interpreting cultural data":

Good references will tell you geographically where the plant originates, and at what altitude it can typically be found. The "where" part can give you some idea of the typical temperatures and humidity levels, as well as possible seasonality, but the "altitude" part may lend information about changing those conditions and adding day-night variations to the mix.

Let's start with seasonality. Species native to equatorial regions may be exposed to pretty much the same temperatures and humidity levels all year. Both will tend to be higher than those seen in more temperate regions, but local conditions can still vary. A plant growing farther from the equator, on the other hand, will see seasonal variation (and likely lower levels) of both, and changes in light levels as well. We are aware that light intensity decreases as one moves from summer to winter, but plants growing in deciduous forests may actually see an increase in light in the winter.

Then there is diurnal range - that phalaenopsis species growing close to sea level near the equator will likely see similar daily highs and lows year round. whereas a Mexican laelia growing at high elevation might see highs in the 80°s and lows in the upper 30°s!

 

[mormodes]

Something I`ve run into often, but seldom thought deeply about is growing altitude of orchids. Whenever I research a particular species of any orchid you always come across this information. While I understand what it means I don`t fully understand how to use this information in my culture.

Internet research has yielded poor explanations.
Is this important, and how do I interpret it?

Cheers

A good example of this is Paph druryi. For some reason I always thought this hailed from the 'foothills' of the Himalayas on the border of India and Bangladesh. I knew it was higher elevations but couldn't get a handle on just what that meant. Then I googled it, found it was from a *completely* different area of India and was able to chase down images of the national park area and mountain its endemic to. Its still found at high altitude, but lower latitude. So now I'm trying to figure out this region's temps, how its affected by the monsoon season, whether druryi likes a rest and when that rest would occur, and its season day length variations. I love this species but it barely clings to life in my collection.

So you're not alone in figuring interpretation of data.

 

[Rick]

In many of the places where our orchids are collected, they are many (often hundreds of miles) from a long term temp gauge (weather station), which are generally in lowland locations (where airplanes can land). So the elevation is helpful for correction factor to the nearest lowland (typically) weather station data.

Although the day length is fairly constant near the equator, the patterns of rainfall, prevalent wind direction, and cloud cover are not constant year round. So even at the equator there are wet/dry seasons, and light/dark (cloudy) seasons. That's why you hear about monsoon and typhoon seasons in the tropics. The seasonality gets magnified with elevation at a given latitude.

 

[Shiva]

Rick:

I used the word constant as general conditions from year to year and not for the whole year. For instance, if the sky is clouded for four months in summer, it will be the same for the same four months every year. So it goes for all other changes in weather patterns, humidity, temperature and so on from one year to the next. I like to be as brief as possible in my posts.
So, if I have been too brief in that matter, thank you for pointing that out.

 

[Shiva]

Curious! The post I was referring to has disappeared.

Oops! My mistake. Everything OK. I had a break down in my Internet connection and when I rebooted the system, I thought something had gone screwy.

 

[mormodes]

In many of the places where our orchids are collected, they are many (often hundreds of miles) from a long term temp gauge (weather station), which are generally in lowland locations (where airplanes can land). So the elevation is helpful for correction factor to the nearest lowland (typically) weather station data.

Although the day length is fairly constant near the equator, the patterns of rainfall, prevalent wind direction, and cloud cover are not constant year round. So even at the equator there are wet/dry seasons, and light/dark (cloudy) seasons. That's why you hear about monsoon and typhoon seasons in the tropics. The seasonality gets magnified with elevation at a given latitude.

In addition to the weather station information Google maps and Google earth allows you to zoom in on the region. If you are lucky some kind soul has posted their vacation images of the region. I was looking up C violacea and the Google Earth images really brought home the conventional wisdom that these grow over streams. It does help those of us who need a visual in order to learn. And luckily people post images of their vacations here or elsewhere on line so we can see plants in their habitat. (I still really like the slideshow of Paph bellatulum in the wild.)

Anyway, now I appreciate why species growers use different colored tags for the microclimates, *G*. I'm just too lazy to do that. But I'd probably be a better grower if I went through the exercise.

 

[Paph_LdyMacBeth]

There are really so many factors that are important to growing our plants well! Thanks everyone for helping me get a grasp on this. Fortunately, I was in the right direction with my thinking on this, but consulting people who know better than I is always helpful.