Arborist test question

[xtremetrees]

If a tree adapts to a hot dry climate what charaistics does it exibit?
A: Develops smaller, thicker, leaves.
b: Develops thinner, broader leaves.
c. Grows thicker bark
d. Develops deeper tap root.

I answered A three times was I right?

 

[darkstar]

test bull???? question .... depends on the SPECIES OF tree IMO

 

[xtremetrees]

Do you mean different kinda trees react in different kinda ways when adapting?
Interesting I looked at a Quercus Negra (water oak) yesterday. It had growths of compartmentalized wood throuought the stem. I thought this abnormality was normal with this species.

 

[Ekka]

Our inland and northern eucalyptus are good examples of getting thicker leaves which also hang vertically so they have minimum exposure to the sun. They also tend to have thick bark, helps with sunburn and moisture retention.

Tap roots are somewhat of a myth though, roots need air. I have to argue about tap roots because when the big dozers clear land and the eucs get pulled over, seldom is there a tap root. But do remember the soil type, if its sandy they may well have deeper roots than in a compacted clay.

 

[underwor]

I would say that you were right extremetree. Less surface area to transpire, per unit of mass of leaf. Also usually silver or light green scales or hairs to slow wind over surface and reflect heat.

I would give you an A.

 

[Kneejerk Bombas]

I agree A is the best answer.
I think of succulents which are drought tolerant and tend to have small, thick leaves.
Thick bark is more of a protective thing, like against fire. Not so much in dry, hot conditions.
The root system develops as a result of species and soil, but I might expect a tree in hot dry conditions to have deeper roots. I don't know.
That's what they want anyway, is just the best answer, not the correct answer. In other words, the least wrong answer.
Back when i took the test there were a few weird questions that just didn't belong on the test. They were questions that had choices that were all wrong or ambiguous.

 

[Gypo Logger]

I would also have to agree with A.
If we look at the most successful trees, ie. Cedars and Pines which by the way are some of the longest lived species and even prehistoric in some cases, we will note a needle leaf that is thick and has a small surface area.
It's a climate/adaptability thing.
John

 

[darkstar]

a b and d are all correct answers [[[[sure answer a is best ]]]]but come on .... take for example a willow ... they will develop just about any root system to reach a water source and they have thin leaves ... in drought the leaves do not get thicker ... i could go on and on ... the pine tree will often grow a very deep tap root in a dry area where as in wet areas the same pine will hardy have any tap roots at all ... mike is so right that what they want the least wrong answer ... i do not like that format at all

 

[Sylvatica]

An example of an adaptation where leaves, due to extreme drought and solar conditions, have modified themselves out of the photosynthesis and evapotranspiration business entirely is the stem succulents (cacti). The stem has become the primary photosynthetic and water storage tissue of the plant, the "leaves" have become protective spines.

 

[treeseer]

what they want the least wrong answer ... i do not like that format at all

dark I agree it can be tough making those decisions. Which format do you think would be better?

 

[xtremetrees]

Sylvatica,
I like reading your post very much. Tree are not much different from humans at all in that in xtreme cold a persons blood will leave the extrimities and go to the trunk. I find it very interesting that the laws that make up the universe are consistent with us.

 

[R Schra]

If a tree adapts to a hot dry climate what charaistics does it exibit?
A: Develops smaller, thicker, leaves.
b: Develops thinner, broader leaves.
c. Grows thicker bark
d. Develops deeper tap root.

I answered A three times was I right?

I dont like the way this question is build. For me the frase If a tree adapts is a asumption and so are the proposed answers. We all know from history and research the way how specific trees did adapt to certain circumstances. Just by asuming that a tree will follow a 'path' to adapt to climatechange or specific climate is not a really sientific aproach to me. Its not that planting a palmtree on the northpole will make it adapt to that climate nor will an artic spar adapt to a desert environment. I have a hard time thinking what this question makes clear in an exam?

For me its more then only climate that stimulates 'life' to adapt. Its all together in that specific environment that makes a tree seek to ways to survive. A strugle for water, against heat, wildlife, fires, storms, humans, bugs, diseases and so on. all do take part in changing a species to survive. And it takes more then a human lifetime to notice differences in adapting, we just see species die and changes in habitats.

 

[treeseer]

And it takes more then a human lifetime to notice differences in adapting, .

Schra, I don't see where the question refers specifically to a specimen, and not the species. Besides, we do :Eye: individual trees adapt their leaf morphology; witness broader leaves in the shade, for instance. I agree that c and d can also be right.

What makes a the best choice is, that is the most universal adaptation. It happens more often in more conditions with more trees than c or d. If anyone has suggestions to improve these exams, there are committees that are ready to get your input and involvement. Seriously, I've attached questions to every cert test I took and I know for a fact that they got consideration, and sometimes action.

"I find it very interesting that the laws that make up the universe are consistent with us." I also find it interesting, and very comforting in a way. :angel:

"roots need air" They do need oxygen, but feeder roots need a lot due to their surface area, while sinker roots need much less. that's why they can go several feet down.

 

[R Schra]

Schra, I don't see where the question refers specifically to a specimen, and not the species. Besides, we do :Eye: individual trees adapt their leaf morphology; witness broader leaves in the shade, for instance. I agree that c and d can also be right.

It does not refer to a specimen or species. the question as beeing an asumption bothers me. As for that morphology, thats already in the trees genetics. At this time i am not aware that trees are following the climate changes in adapting to those changes. They simple die, disappear and will move/migrate to better climate zones. (not that fast but they will do)

What makes a the best choice is, that is the most universal adaptation. It happens more often in more conditions with more trees than c or d.

i agree, to pass a exam just fill in the best 'logic, answer. No problem with that.

If anyone has suggestions to improve these exams, there are committees that are ready to get your input and involvement. Seriously, I've attached questions to every cert test I took and I know for a fact that they got consideration, and sometimes action.

Lol, did i do give feedback on examens questions i have had. most times they didnt bother to take notice.

"I find it very interesting that the laws that make up the universe are consistent with us." I also find it interesting, and very comforting in a way. :angel:

ummm, example please so i get the intention ment with that statement? (poor exuse, i am a foreigner)

"roots need air" They do need oxygen, but feeder roots need a lot due to their surface area, while sinker roots need much less. that's why they can go several feet down.

mmm, how much of the trees needed water is put up by just roots effectifly? I think most capacity (x100 of the trees own capacity) is provided by micorizha. in soils with deep water levels and just natural resources like rain and the presence of good open soil i think that the combined root/mycorizha will make the tree penetrate deep with a 'taproot'. The mycorizha also penetrate much smaller 'holes' as a root and might 'guide' a root to the neccesary water and/or organic material. I dont think that surface- or tap- roots have different need for oxygen.

 

[Gypo Logger]

What is more important than the way the question is asked, is the thought that it provokes.
In other words it gives us all a chance to be,"professors".
Obviously the main function of any vegetated matter is photosynthesis which incidently includes the making of ozygen by taking in carbondiozide.
However, upon a much more closer examination, trees, shrubs and grasses, as a secondary function, not only mantain water levels but also hold the soil together against erosion.
This erosion control is usually established by so called "inferior species", such as Willows, Birches, Poplars and Spruces, which so happen to be the most hardiest bit of greenery that I have ever witnessed, even though short lived in some cases.

See there, now didn't I sound like a bleedin University proffessor? And I came up with that all on my own.
John

 

[Gypo Logger]

Ya see.... even TreeCo noticed I'm not as dumb as I look!
In fact, I think I sound so darn smart and inteligent that I bet Tom Dunlop might even lower himself to talk to me.

John

 

[Gypo Logger]

Dan, I am glad you made that distinction, because I was thinking about adaptation and aclimization while I was in the Yukon.
We have all heard about how well some species can be naturalized when moved from one clime to another, whether it is deliberate or by accident.
The White Poplars and Cottonwoods in the Yukon/Alaska obviously live under very harsh conditions which makes me wonder how a specimen from up there would do down here.
John

 

[Gypo Logger]

After pondering my own question, I guess it would be the same as asking how well an Eskimo would do in Florida, or how well a Zulu warrior would enjoy the Arctic Circle.
It's an evolved adaptability thing, which lends some credence to Treeseers tree/people analogy. So the bottom line is: are we a feature or a fixture?
John

 

[Sylvatica]

Tree are not much different from humans at all in that in xtreme cold a persons blood will leave the extrimities and go to the trunk.

There is a theory that some northern Europeans have a genetic adaptation to blame for diabetes. Their ancestors modified their blood sugar - increasing it may have been a survival response to cold and frostbite. The sugar in the cells lowered the freezing point. This type of evolutionary change, like sickle cell anemia, is a response to environment/pathogen.

how well an Eskimo would do in Florida, or how well a Zulu warrior would enjoy the Arctic Circle.

The biggest difference between the plants and the animal kingdom is that the animals are mobile. The plant, once germinated, can not move. If the condition to which it is adapted changes drastically or no longer exists, it is very unlikely that organism can adapt on the spot. If the animals (and humans) find the location unsurvivable, it attempts to relocate. If a contingent from the Zulu tribe moved to an arctic climate, they would be significantly physically different in 30,000 years.

A zone 2 plant, even if it could relocate itself, is not adapted to zone 11. An interesting characteristic in a few plants is broad adaptability, one which can survive from zone 3 to zone 9, and from a wetland site with total groundwater inundation for a month as well as a well drained mesic site: Acer rubrum.

In very general terms, humans and plants share the capability to adapt and evolve. Anthropologists know that a pair of humans can migrate to a new land, richer and more productive in survival assets than where they came from, and their offspring will suddenly jump in size - in just one generation! Their kids will ultimately be much larger than any of their ancestors from the region which they had previously adapted to, where larger people would have been genetically de-selected since the assets to support them did not exist there.

 

[darkstar]

tree co ... yes [[[a is the obvious most correct answer for test sake and test sake only ... where is your creativity ... ie ... thinking outside the box ..... tree seer ,,,, i like questions where it yes or no ... or better yet ask a question and give the student 1000 words to answer ? then be judged by several pros ....
tree co .... einstien would have failed this question seriously .... he would have had to many answers ..... get my drift .... so as i said at the start this question is nothing but fodder ...