Plant nutrition

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Photosynthesis
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How plants make their own food – requires sunlight -requires water & nutrients
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Autotrophic
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able to make their own food and eat it (most plants can)
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Problems: Nutrients – Heat (ericaceous -Fungas -Symboitic -orchids -myccorhizae
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• Some habitats are nutrient-poor – Bogs are one of them • In a true bog nutrients only come from rain fall • HEATH (Ericaceous) plants are commonly found in bogs • If plants are living in a nutrient poor area they will ‘get by with a little help from their friends’ – Heath plants have fungal partners • Fungus helps plants get nutrition through their roots – MYCORHIZAE inside of roots are called Endomycorrhizae – they are inside of the root travelling through the root networking fungal threads pulling in nutrients • Symbiotic- plants get nutrient, fungus gets home • Orchids also have Endomycorrhizae associations • Myccorhizae allow plants to grow in bogs as well – Black Spruce have myco that starts on the outside wrapping around forming a sheet around the roots called Ectomychorrizzae
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Mycos
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1. increase uptake of nutrients such as N and P – they bring the nutrients into the plant 2. Prevent uptake of toxic compounds – if there are bad chemicals the fungus acts as a barrier to it
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Myco: alders – fix nitrogen – adheasive traps
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• Alders have a different solution for N – Alders have Root Nodules – nodules are full of bacteria inside of their roots that convert the nitrogen from a form the plants can’t use to a form that they can use – this is called FIX NITROGEN • Some plants eat animals to absorb their nutrients – Carnivorous plants – eating insects primiarly (insectivourous) – Sundews • Outer hairs have an adhesive liquid that makes insects get stuck and the more the insect tries to escape the more stuck it gets – and when the leaf folds over the inner hairs release enzymes of digestion that dissolve the insect to it’s basic parts that are absorbed by the leaf pad of the plant – ADHESIVE TRAPS
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myco: pitcher-plants – pitfall traps
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• Pitcher-plants are also ‘carnivourous’ they have modified leaves • Downward pointing hairs direct the insect to a slippery death slide • It attracts the insects by leaving drops on the leaves that ants typically like • As leaves change they change their strategy and ants leave the odour of death that draws in scavangers (flies) Brood Site Conception to get insects to lay eggs – PITFALL TRAPS
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Myco: Bladderworts (aquatic plantss) -suction
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• Their underwater leaves are SUCTION TRAPS • Little hairs are trip wires and when a small animal in the water hits the hairs the hair makes the trip lid go up and the vacuum inside sucks the insect in and the trap door closes where it is dissolved down by enzymes
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Shade (lack of sunlight- which is needed for photosynthesis) – Large size -natures toilet paper
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• Adaptation for shady habitat would be big leaves – a large surface area for capturing sunlight and manufacturing food – bigger the leaf the bigger the sun trap (Round Leaved Orchid) • Round Leaved Orchids are also parallel (flat) on the ground and therefore they get more sunlight – the more flat they are to the ground the more sunlight they can catch • Thin leaves put less tissue into making leaves so this saves energy and makes less material – sunlight hits the photoactive cells more quickly and therefore a faster response to sunlight – also suppresses competition because other leaves cannot grow close • Hobblebush plants have huge leaves that are soft and large are often called ‘Nature’s Toilet Paper’ • Chlorophyll B is more sensitive than Chlorophyll A – B collects more luck and is found more in shade plants
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Some shade plants increase their leaf surface area by having many leaves
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• Bunchberry leaf surface area is increased by having lots of leaves • Leaves are attached to a shared rhizome (rhizome is a stem that lies flat on the ground rather than vertically) • Clonal growth or colonial – grows as one big massive plant with many leaves
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Another way to beat the shade is to grow away from it – phototropism
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• Plants that change their direction of growth are called PHOTOTROPISM – if it goes toward the light it is called positive phototropism
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Antoher way to beat the shade is to climb atop the competition
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• Wild cucumbers grow atop other plants • They have an adaptation that wraps around plants pulling them higher and higher – Tendrils are Thigmotropic – when a tendril touches a plant it curls around it
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Trilliums have another solution for beating the shade
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• Trilliums grow in the Spring before the leaves in the trees open – end of April to early May • Many species of SPRING EPHERMERALS (grow in the spring) grow in deciduous forests
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No solution is perfect
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• At mercy of climate – if it turns cold below zero you risk the dangers of that • Frosts can also have a negative effect – really cold temperatures don’t allow insects to fly so pollination will not occur
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Another solution is to lose the need for sunlight entirely
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• Some plants like Coralroots have no leaves – Saprophyte’s live on decaying plant matter (like a Turkey Vulture in the animal world) – they are more thieves as opposed to scavengers • They have an adaptation for stealing food that is on their roots – their roots have fungal partners that steal the photosynethis carbon products (carbon products come from living plants) • This means they have a mychorizae • Coral roots are Heterotrophs but because they use a fungal partner they are a special kind of heterotroph called Mycoheterotrophs
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Indian Pipe flower
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• Indian Pipe is a wildflower that also doesn’t need sunlight because it has Mychorizal associations • Indian pipe gets nutrients from living plants – it lives like a parasite
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Shade dwelling orchids
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photosynthesize AND steal carbon from other plants through mycorrhizae – MIXOTROPHS given that these plants partly make their own food but also steal foods
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Canerroot has NO leaves and NO mychorrhizae
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• They steal directly from another plants roots – they steal directly – OBLIGATE PARASITE • Its roots form haustoria (structures that arise on the roots of the other plant that are direct outgrowths of the canceroot touching other roots) in the roots of other plants which is finds by tracking their strigolactones • HOLOPARASITE
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Witch brooms
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• Abnormal growths where the branches grow stunted and the needles do not fall off and grow dense are called Witch’s Brooms which are caused by Holoparasitic WildFlowers – their seeds fly through the air and rain makes a seed slide down a needle penetrating cells and stealing food from the cells causing a weird growth – Dwarf Mistletoe is the wildflower’s name
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Lots of Sunlight
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• Smaller leaves – smaller surface area • Avoids dehydration or sun burn • Buttercups have tiny leaves • Leaves grow on 45 degree angles to absorb less sunlight (like in Buttercups) • Sand dunes are particularly hot – plants here often have leaves that are higly dissected • The leaves are cut into smaller pieces – they are dissected to allow for a smaller surface area Plants are very much like animals except that many plants can make their own food

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