Here's something for you guys, when you are out and about admiring the beautiful autumn hues, and wondering what brings about the leaves to change their colour.
It has been hypothesized, shorter days and chillier nights cause the leaves to change colour. The yellow colour appears when chlorophyll (responsible of the green colour) breaks down in aging leaves. The orange colour appears if newly produced red pigments aren't dominant yet, and the pigment is blended with the revealed yellow. Leaves eventually turn red, so they can repel egg laying bugs or guard nutrients from sun damage so the tree can retrieve them for future use.
It has been hypothesized, shorter days and chillier nights cause the leaves to change colour. The yellow colour appears when chlorophyll (responsible of the green colour) breaks down in aging leaves. The orange colour appears if newly produced red pigments aren't dominant yet, and the pigment is blended with the revealed yellow. Leaves eventually turn red, so they can repel egg laying bugs or guard nutrients from sun damage so the tree can retrieve them for future use.
Moreover, climate change hasn't been too kind on foliage, as autumn is getting warmer and drier. Drought causes leaves to turn brown and drop off early. Whereas, cloudy days slow down the creation of red pigment, resulting in more yellow leaves.I just looked out the window at my cherry tree, majority of the leaves are still green, and a small number have turned yellow. Whereas, mulberry, pear, apple and peach trees are still very green. (Yes, I live in a farmhouse :D). The cherry tree gets more sunlight compared to the rest of them so maybe that's why its leaves are turning yellow first. Plus the cherry tree is the first to blossom too. Hmm, maybe I should have paid more attention in Ecology.
Sorry for boring you guys with these facts, which you probably already knew from before.
Source: October's National Geographic
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4 comments:
That's all right; they weren't boring. It's a good refresher of things I learned (or didn't learn) in Biology. (I love biology, but my teacher was pretty lackluster.) Climate change definitely seems to have an effect on fall foliage. I feel like the colors aren't as vibrant as they were just a few years ago. :(
I agree. But I am still awestruck by the beauty. It just makes me want to go bike riding or something. Too bad autumn also brings stinkin' cold germs, along with the beautiful hues.
Thanks for your comment :). I like human biology, never liked ecology or botany. I found it very disturbing when my profs or teachers talked about plants as if they had anthropomorphic traits.
I miss reading National Geographic, at some point in late 2006 I found I didn't have the time to read them all and they were piling up so I had to stop my subscription =(
Josh, I know what you mean. I haven't renewed my subscription either. I struggle to find time to read them cover to cover. Too much to read in too little time :(.
Thanks for your comment :).
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