how do the trees cause rain?
488248
Water loss from leaves is called transpiration and is greatest when it is hot.\nWhen a mass of warm, moist air is cooled the water vapour will condense and clouds are seen. As cooling progresses the droplets coalesce and fall as rain.\nThis cycle is most obvious in rain forests.\nBoth transpiration and evaporation from the sea and lakes contribute to water vapour in the air, but over continental areas transpiration from trees is of greater importance. Deforestation in these areas leads to dessertification.
336031
When rain drops fall through the atmosphere CO2 becomes dissolved in the water. Dissolved CO2 makes water acidic.\nCO2 is a normal component of the Earth's atmosphere, thus the rain is considered naturally acidic.
1036321
The individual drops of rain usually form as pure drops of water.  As these drops fall, they encounter gases in the atmosphere which can be absorbed and react with the water.\n\nMost of the gases are oxides of nonmetal elements.  When they react with water, they form acids.  This is the source of "acid rain."\n\nFor example Nitrogen dioxide reacts with water to form nitric acid.
562921
High pressure is hot. If it hits a low pressure area, you get rain.
1152801
Leaves sense the change in moisture in the environment with the coming storm. The stomata (openings in the bottom of the leaves only to exchange carbon dioxide and oxygen, with some water vapor needed for photosynthesis within the leave) take advantage of the added water source available from the air by rolling over temporarily to take on some water. They go back to normal when the rain starts so that the openings are not exposed to the rain and drown the openings.... Also, some leaves have flat petioles, (leaf stems) that make them roll over in the wind. Have you ever seen a quaking ASPEN tree?  It shakes in the wind due to its flat stem structure of it's leaves....I can go on and on......hope this helps.....   :-)
714393
The water's in a vapor form which makes it much much lighter than if it were in liquid form, and there are air currents within clouds that keep the vapor circulating around and are able to hold the water up against gravity.  It's when water vapor starts forming droplets that it gets too heavy for clouds and we get rain, hail, etc.
328151
I would think because the forest canopy shelters the ground from rainfall/snowfall and therefore less erosion takes place down below. I actually just read something very interesting about this: In the Redwood Forest there are parts where the forest canopy actually is dense enough that it creates a whole new "ground" hundreds of feet above the ground. There are even more trees that are growing out of it, as well as plants and animals that are normally found on the actual forest floor!\n\nPS- I'm assuming you mean "watershed" as a ridge of high land dividing two areas that are drained by different river systems.
1183698
It helps with the environment in many different ways such as increasing the annual rainfalls, keeping the environment cool, and decreases the ratio of wind evaporation which saves the atmosphere from becoming dry. This provides immunity to inhabitants of such areas from chest and respiratory diseases. The tree helps in stabilizing canal banks and preventing soil erosions
585225
The chemistry is in the changes in the state of matter & water's properties such as cohesion & adhesion.\n\nWater is evaporated from the earth's surface, rises with warm air masses, cools & condenses on condensation nuclei w/in the upper atmosphere (property of adhesion). Clouds form & continue to build as long as there is updraft (warm rising moist air).\n\nBecause of water's property of cohesion, the tiny water droplets will begin sticking together. When they become too heavy to w/stand the pull of gravity, they will descend & fall as rain.
642859
The tree uses different systems or parts of the body for adaptation of a certain environment. \n\nFor example. The tree which grows in a desert condition will have less leaves and thick leaves (Adaptation to preserve water and minimize evaporation) Roots will be tug deep to find water. \n\nAir affects the trees if there is too much of wind blowing in that cases trees tend to be deep rooted and less broad to with stand the winds. (example coconut trees in sea side)
467833
In some countries, they spray the top of the clouds ("seed the clouds") with chemicals (AgI or AgCl).  This causes the small water droplets in the cloud to grow, and finally the drops are big and heavy enough to fall to the ground in the form of rain.\n\nThe reason for doing this could be that you really don't want rain in a certain area, and you think it is a better idea to make the potential rain clouds "release the rain" in another area, before they have moved with the wind to the area you want to protect.\n\nSo, the rain is not really artificial, but the cause of the rain is artificial.
343628
figure the bottom, the top gets fed more water as it flows down river by rain, the bottom gets its water from runoff - the effect of the rain up-stream.
510562
forest fire, usually started by lightning, is one especially during the dry seasons. on the rainy seasons, there is a threat of avalanche if the trees are not numerous enough to hold the massive downpour from eroding the soil on the steeper sides of the mountain. earth quakes may also cause avalanches in addition to massive downpours.
310693
All spring and summer there is a lot of water to keep the trees well watered.  They use their leaves to convert sunlight into energy, but this uses up a lot of their water, so they have to keep drinking a lot from their roots.  In the winter it is too cold outside for the trees to drink because the ground is frozen and so is all of the water.  Therefore the trees go into a kind of hibernation, just like bears do.  The shed their leaves because they don't have the resources to hold onto them all winter.  \n\nThe trees also move all of the energy that they have gathered all summer from the sun and the extra water they gathered into their roots.  They take all of the nutrients from their leaves, so they change color, and they move them to their roots.  This way the tree's food is safe all winter.  Then because the trees no longer have any use for their leaves (which used to gather energy from the sun), they let them go.  That leaves all of us with leaves to make into piles and play in!
920040
There are several ways that fires affect weather.\n\nFires send particles into the air.  These particles act as condensation nuclei, which are needed to form clouds and can lead to rain.\n\nThe smoke from a fire can also block sunlight, lowering temperatures slightly.\n\nIn the immediate area of a active fire, the energy released can create thunderstorms and lightning, which in turn can spark more fires.
577404
Deforestation. When Man gets rid of trees, the  soil can easily be eroded. Also, where there are many trees, as my grandmother used to say, they 'attract' the rain, ergo when deforestation takes place, water catchment areas cease to be that. It's a nasty cycle that just goes on and on until the land becomes completely arid.
1183383
The sky is beautiful, but clouds are just water vapors. How does a tree grow? Photosynthesis. Knowing how something occurs does make it less beautiful does it?