Wikipedia:Reference desk/Archives/Science/2018 September 20

= September 20 =

Particles, wood heating & diesel
Hello! The dieselgate has brought to light a fraud involving toxic emissions from diesel vehicles. In the case of fine particles, total pollution includes emissions from industry, transport, individual heating &c. How is each contribution calculated? If transport-related emissions have long been undervalued due to car manufacturers' fakes, what is the adjustment factor and have we not, for example, exaggerated the impact of wood heating? Thanks for your help, --methodood (talk) 10:34, 20 September 2018 (UTC)
 * Dieselgate redirects to Volkswagen emissions scandal. Is that what you're referring to? Also, where have you been for the last eight years. :) ←Baseball Bugs What's up, Doc? carrots→ 13:02, 20 September 2018 (UTC)
 * Hi Bugs! Can you give me the detail of the contributions of each pollutant before and after the revelation of the scandal, how it is calculated (and if the prorata didn't evolve, why ?) Thank you.--methodood (talk) 18:31, 20 September 2018 (UTC)
 * Dieselgate is only about NOx emissions. Fine particle emissions were not involved. Ruslik_ Zero 20:22, 20 September 2018 (UTC)


 * These numbers are all estimated (numerically projected) based on a few samples. If you manipulate some samples you of course also manipulate the whole picture and change the relation of all picture elements among each other. That does not mean you change every element and its own impact! --Kharon (talk) 22:54, 20 September 2018 (UTC)

Plants question.
If you bring a plant from the cold arctic, like coniferous trees, and bring it to the tropics, equatorial regions, will it be happy, or worse? Cuz I imagine the other way around is more painful, bringing a tropical plant to the cold arctic. So when you bring a arctic plant to the warm regions, with more sunlight, what would be the answer? If things like different soils play a role, then what about if you bring the same soil and so the only changing variables are temperature and latitude? Thanks. 12.239.13.143 (talk) 21:21, 20 September 2018 (UTC).


 * Depends. I don't have an answer to your actual question, but will note that the equator is not all happiness and sunshine from every plant's perspective. Heat and high humidity are downright stressful for some of them. Someguy1221 (talk) 21:48, 20 September 2018 (UTC)


 * Not all but many plants are specialized on specific environments and according conditions. Arctic plants for example tend to have a very slow metabolism that probably cant "deal" with the energy volume of sunlight in warmer regions, just like you cant put a Seacow into the Rapids and expect it to survive and reproduce there. --Kharon (talk) 23:14, 20 September 2018 (UTC)


 * Do yo mind providing any source to your claim that "Arctic plants for example tend to have a very slow metabolism"? Is that something you can cite or just imagined to be the case?
 * Indeed, arctic plants very fast development, high rates of metabolism concentrated in a short period of time, when there's sun available.
 * In contrast, in season-less tropical climates, plants can compensate for low rates of metabolism by having long durations of activity. There's plenty of sun for that.
 * In any of both cases, the evolutionary adaptation is the lowest temperature at which new cells can be generated.Doroletho (talk) 01:50, 21 September 2018 (UTC)


 * According to this source "the vegetation of the taiga is vulnerable because of its low rate of metabolism and biological activity due to cold temperatures". Mikenorton (talk) 09:16, 21 September 2018 (UTC)


 * But there's a question of chicken versus the egg: does their metabolism appear to be slow because of the reduced sunshine for much of the year or is it really slow? It's a question of lack of resources versus internal mechanisms. Anecdotally, northern plants are certainly capable of rapid growth when conditions are ripe (broadly similar to a desert bloom) and the stunted "trees" around the treeline also grow bigger and faster further south. Whether they're genetically tuned to grow differently is really the crux of the question. Matt Deres (talk) 15:10, 21 September 2018 (UTC)


 * Sunshine seems less important than temperature because you find the very same strategy and adaption for example in Greenland sharks who are even apex predators aka Carnivores in their environment, thus hardly dependent on allot of sunlight, have a even extremely slow metabolism and obviously no interest to leave their very cold environment. --Kharon (talk) 17:11, 21 September 2018 (UTC)


 * Wait a minute you're comparing plants to animals here?? Plants need sunlight to photosynthesize, animals do not. 67.175.224.138 (talk) 05:57, 22 September 2018 (UTC).


 * Hence: asking for real sources rather than "I imagine that" is the way to go. --Doroletho (talk) 13:01, 22 September 2018 (UTC)

Okay I asked 2 plant professors this question. 1st 1 said for coniferous trees, yes it can as it is strong enough to live in both environments. But not all Arctic plants. Basically his ultimate answer was "depends on the plant." A 2nd 1 predicted that if you move a plant from the Arctic to the tropics, it will have problems where it loses a lot of water. But I ask what if it were moist, rainfall environment, so he goes on with other factors like being exposed to different kinds of bacteria and fungi. So it seems to me, that placing a plant from a wet environment to a dry environment is a bigger issue - so now my 2nd question is - what happens if you bring a desert plant like cacti into a moist, rainfall environment? I'll later ask around about metabolism. 207.140.218.10 (talk) 17:40, 21 September 2018 (UTC).


 * Many (but not all) cacti will suffer root rot if they are in a wet environment. I wouldn't even try to grow a cactus where I live with a hundred inches of rain a year.  Even Mediterranean plants tend to rot here, but conifers grow well.  Here is a Quora answer about cacti.   Dbfirs  19:39, 21 September 2018 (UTC)
 * You could probably grow them indoors as long as you don't overwater. --47.146.63.87 (talk) 06:50, 23 September 2018 (UTC)
 * Well, yes, I do grow small ones indoors where they seem to thrive on neglect most of the time.  Db<i style="color: #4fc;">f</i><i style="color: #6f6;">i</i><i style="color: #4e4;">r</i><i style="color: #4a4">s</i>  10:20, 23 September 2018 (UTC)
 * Here in So Cal we tore out our lawn and replaced it with xeriscaping, which cut the water bill by about 60%. With a drip irrigation system you don't even have to think about the plants. Should be mandatory around here if you ask me. --47.146.63.87 (talk) 22:15, 23 September 2018 (UTC)

Not about conifers, but here's some comments from the University of Florida (http://gardeningsolutions.ifas.ufl.edu/plants/edibles/fruits/chill-hours.html) regarding deciduous fruit trees - "In order to bloom in spring, deciduous fruit trees like peaches, plums, and nectarines all must go through the plant equivalent of a long winter's nap. They need a dormancy period with a certain number of chilling hours, when the temperature drops below 45 degrees Fahrenheit. The exact number of chilling hours depends on the fruit tree variety, but it can be anywhere from a hundred to more than a thousand....." So, your peach tree might survive in the tropics, but may not set fruit. HiLo48 (talk) 22:47, 22 September 2018 (UTC)

207.140.218.10 already hit the points I would have emphasized; there's simply too many varieties of flora within the meaning of "arctic plant" to give a very straightforward answer. In generally, shrubs, grasses, bryophtes, and flowering plants from the arctic region tend to be highly adapted to the local ecology and do not adapt well to local conditions in the tropics. The afore-mentioned fungi, bacteria and other pathogens, heat, humidity, soil conditions, difference in light and difference in seasonal variability of all of those factors conspire for an inhospitable environment for many species. However, hardier vascular plants, including most conifers, tend to do quite well. Conifers as a clade, you must remember, are not restricted to the arctic (though a small handful of species are adapted to the arctic circle) but rather extend across nearly the entirety of inhabited terrestrial latitudes, generally thriving in most. As a consequence, and because of their high value as timber resources, and as useful species for arresting soil erosion (particularly after previous deforestation following fire or over-harvesting), conifers (softwood pines in particular) have been imported into many of the few regions on earth where they do not occur naturally, including numerous tropical islands.

Additional reading you may find interesting, regarding the distribution of conifers:, , ), and regarding the success of the clade in tropical climates, one of the better studied ecological test cases is Hawai'i, to which story these sources pertain: , , , ; I was actually going to tell a long navel-gazing story about how I became aware of the ecological history of pines in Hawai'i and the interesting contrasts they create when the intermingle with the species of the native arboreal and bamboo forests and scrublands, but the sources are probably more useful to your purposes. <b style="color: #19a0fd;">S</b><b style="color: #66c0fd">n</b><b style="color: #99d5fe;">o</b><b style="color: #b2dffe;">w</b> <b style="color: #d4143a">let's rap</b> 06:16, 26 September 2018 (UTC)