#guy-barter #royal-horticultural-society
Plants are unlike animals in that they age unevenly. An animal ages uniformly - a tiger's tail is as old as its ears and its liver - but the growing tips of tree shoots and roots can remain young and active, often for centuries, when the main part of the tree is in decline. Trees are also able to compartmentalise damage, an asset that can enable them to survive some serious mishaps, including accidents and the ravages of pests and diseases. #ageing #trees
Many airborne seeds are tiny; orchid seeds are microscopic, hardly bigger than a speck of dust. 1,000 willow seeds weigh just 0.05g. For comparison, 1,000 rice seeds weigh 27g.
The root/shoot balance is the mutual dependence between the roots (which are necessary to supply the shoots with water and nutrients) and the shoots (which feed the roots with sugar made by the process of photosynthesis in the plant's leaves). There must be healthy roots to feed the shoots, and vice versa. And if the shoots are pruned back, the roots will carry on feeding new growth to compensate. The tips of branches in which a plant's cell dividion and growth happen are called the apices. One of their jobs is to send inhibiting hormones back down the branch to stop lower buds from shooting, so that growth in concentrated at the ends of the branches - in technical speak, they 'dominate' these lower branches. But when you prune a shrub, and cut the branch tips, the hormones are no longer sent back down to the lower buds. Thus, the inhibition is lifted, and there will be a sudden flush of several shoots.
Lawns are artificial communities, maintained by mowing and feeding to give the lawn grass - short and often 'creeping' in habit - an edge. As a lawn matures, however, weed grasses such as the atmospherically named Yorkshire fog, Holcus lanatus, will creep in and, if control stops, will literally make hay, and quickly dominate. Given more time, as months changed to years, tree seedlings would grow. Birds would excrete pips and squirrels would bury acrosn and nuts, while airborne seeds such as sycamore, Acer psuedoplanatus, and ash, Fraxinus, would soon arrive. Soon there would be the makings of a forest - the natural state of most British land. Within a decard or two, the short lived trees such as birch, Betula, and willow, Salix, would themselves give way to ash and oak, Quercus. Given long enough, the landscape would be completely wild, ready for the return of beavers. #rewilding
Unlike animals, plants are static, so they cannot seek out a mate, but they need help to reproduce - and this is the secret behind their diversity. The various solutions that they find also make them extraordinarily important to other systems, both micro and macro: their role goes far beyond their own survival.
The vast majority of flowers are hermaphrodite, having both male and female organs - the botanical term for this is 'perfect'. The male elements of a flower are the stamens and the pollen on them, while the female parts are the carpels, each of which holds an ovary at its base. The gametes, or sex cells of the plant, reside in the pollen grains and ovaries respectively.
Ever pollinator has its preferred range in the colour spectrum. Flowers that have evolved to be pollinated by bees tend towards the blue-to-violet range (particularly those that also gleam in ultraviolet light, invisible to us). Birds, though, favour red and orange flowers, while butterflies have slightly more adventurous tastes, going for oranges and yellows, as well as reds and pinks. And bat and moths, uninfluenced by colour, have their own nocturnal favourites, invariably white, but always powerfully scented. #colour
Bees can see ultraviolet light and a range of blues, yellows, greens and violets, but they cannot see red.
It's hard for us to look at a flower garden and see the battle for survival taking place. To plants, though, how well they have adapted to reproduce is a matter of life and death. And all their weapons are minutely graded and measured, whether they consist of colour, structure - or scent. #survival
How a flower smells comes from both the number of scent molecules it contains and the proportions they are arranged in. Not only that, but the scnet is mutable - a flower can change both its strength and its quality at different times and for different reasons.
Essentially, a fruit has seeds and a vegetable does not. Certain anomalies, such as seedless grapes, immeditely undermine the simplicity of this explanation, so it is more accurate to say that fruits arise from the ovaries of a plant, while all other parts of the plant - flower buds, stalks, leaves and roots - count as vegetables.
Which wildflowers rank best for nectar? In tests, a number perform well, but white clover is always near the top of the chart. It produces nectar steadily throughout the day, and appeals to a wide variety of pollinators. A UK study from 2007 found that just three plant species (white clover, heather, and marsh thistle) produced almost half of nectar available to pollinators countrywide.
Worms take in organic matter, such as leaves, through their mouths and digest them in the 'gut' that runs from one end of their segmented body to the other. Like all animals, worms must breathe, which they do through their skin (this must always be moist). They have a circulatory system that contains blood, which is supplemented by another system that moves fluids around their body. They have a central nervous system that controls muscles in each segment, and each segment has bristles to grip the soil, and secretes mucus to ease the worm's passage. Just because they have no brain does not mean they are not sophisticated. Worms are amazingly mobile in the soil, not only do they make tunnels but they are also capable of seeking and handling food and making a hasty escape from predators. #intelligence
Soil plays a crucial part in its own right, but it is also home to a number of environmental heroes, including microbes (not for nothing is soil known as 'the poor man's rainforest'); earthworms, which areate and enrich the soil, and fungi, which are the accomplished biochemists that transform unrotted organic matter into plant foods and humus. #soil
The parent of all soil is rock, and it takes an extraordinarily long time to form - anything from 500 to 1000 years to crush and degrade the rock sofficiently to make just an inch of soil.
One teaspoon of healthy, fetile soil contains a billion bacteria as well as tens of thousands of funghi, algae and other microscopic organisms.
Soil tends to be seen, mistakenly, as an endlessly renewable resource. But the soils used currently in agriculture were made under natural ecosystems over very long periods. When soil is 'domesticated' in agricultural use, the wild plants and animals that played their part in building it up are replaced by simplified agrilcutural systems that degrade the soil rather than contribute to it.
While thunder isn't really beneficial at all, the lightning that usually goes with it can offer an indirect plus for plants. The electric charge it brings has the side effect of freeing up nitrogen from the atmosphere and offering it as a quick dose of fertilizer to the rain-saturated ground. #nature
A sudden and unexpected late frost can be devastating to plants. Without a period of increasingly cold temperatures in which to prepare for freezing, it can be fatal. Hardening, the process by which plants ready themselves for tough times, can happen only when temperatures drop gradually, and it is reversible in spring whn the harsh weather is past. More worryingly, though, it can also be reversed if there is a mild spell in winter - and if this is followed by a hard frost, the resulting lack of rdefenses can severely damage or kill the plant.
Hardy plants have two tactics in their repertoire to help them with very cold temperatures. The first is the hardening process, and the second is a process known as supercooling.
The hardening process involves an increasing in dissolved sugars and other organic molecules inside the hardening plant's cells. These help lower the point at which the cells might freeze and prevent ice crystals - which might puncture the cell walls - from forming. The process works like the antifreeze you put in a car, and can stave off ive down to about -2ºC. This is a relatively slight protection, so it seems likeliest that the role of the 'anti-freezing' chemicals is also to regulate the rate and location of subsequent freezing in the plant, which will then work in conjuction with supercooling.
Plants 'supercool' when the temperature on several successive days goes down to 5ºC. This prompts many hardy plants and trees to prepare for deep cold. Once prepared, their cell sontents can go down to temperatures as low as -40ºC without freezing solid. This is due to the fact that there are no small particles or bubbles within the plant's cold sap to act as nuclei for ice crystals, which need nuclei to form. If a hardening period does not take place, supercooling will not happen either.
Even these tactics are not enough in very cold arctic and apline regions. Birch, Betula, and willow, Salix, trees in these extreme situations have another process they can call on: they can remove water from their cells and plate it between cell walls, where it freezes harmlessly.
Vegetables often store most of their winter food reserves in the form of starch; in cold weather, this breaks down to produce sugars: hence the improved flavour of the crop.
The average British garden has between six and ten species of bee as visitors in a typical summer. These are usually a mix of honeybees, which live in hives; bumblebees, which group together in small colonies, and solitary bees, which, as their name suggests, live alone.
It may not be good for listing human spirits but environmentally at least, prolonged drizzle is the right kind of rain. #rain