Saturday STEM Challenge: Designing Alien Plants
In honor of National Wildflower Week, this week’s Distance Learning offerings are focusing on the plant world.
Plants come in all shapes and sizes, from tiny blades of grass to giant redwoods and desert cactuses to ocean kelps. In the same way that animals evolve to thrive in their habitats, plants adapt to the environments that they grow in. The plants you see growing in New Hampshire are different than what you would see in Alaska or Costa Rica or Australia, because each of these places has a different biome.
Biomes are a way we categorize different parts of the world, and we define biomes by the plants and animals we see living there, as well as by other observable factors, like weather, climate, and soil type. Since there are so many different things to observe in the environment, there isn’t one unanimously agreed on breakdown of biomes. However, below we list one commonly accepted separation of the world into nine biomes. For each biome, notice the characteristics of the different plants that grow there.
Desert
Image credit: Pexels.com; Pascal Claivaz
Deserts are defined by their minimal rainfall throughout the year. Deserts can be hot, like the Sahara in Africa, or cold, like Antarctica. Because this environment is so dry, plants that live here need to be good at storing and finding water. Hot desert plants often have shallow and wide root system to absorb as much water as they can and thick leaves and trunks with waxy coatings to store water and keep it from evaporating. Cactuses are often found in hot deserts, as well as shrubby bushes and trees like desert sage, Joshua trees, and creosote bushes. Some plants do grow in cold deserts, like algae and grasses, and they usually grow in the spring and summer.
Saguaro Cactuses
Image credit: britannica.com
Joshua trees
Image credit: National Park service/Larry McAfee
Creosote Bush
Image credit: Nature's Images/Science Source
Antarctic iceberg with brown algae
Image credit: antarctic.gov.au; Kerry Steinberner
Tundra
Image Credit: Thoughtco.com; Paul Oomen / Getty Images
Tundra is flat and cold with a thick layer of ice (called permafrost) below a thin layer of soil. Because the layer of soil is so shallow, plants with deep root systems, like trees, can’t grow in this biome. Plants like lichens, moss, and small shrubs adapt to the tundra by growing close to the ground and each other to protect themselves from chilly winds and are able to photosynthesize (i.e., get energy from sunlight) with low levels of light. Some examples of plants you could see in the tundra are caribou moss, pasque flower, tufted saxifrage, and arctic willow.
Caribous Moss, also known as reindeer moss or reindeer lichen
Image credit: discoveryyukon.com
Pasque Flower
Image credit: Gardenia.net
Tufted Saxifrage
Image credit: conserve-energy-future.com
Arctic Willow
Image credit: Grida.no; Peter Prokosch
Taiga (Boreal Forest)
Image credit: conserve-energy-future.com
Taiga forests are also known as boreal or conifer forests, as they are mostly inhabited by conifer trees, like pine trees and other evergreens. The taiga biome has long cold winters, and so the plants that grow here have adapted to that. Conifers have needle-like leaves that loose less water and shed snow easier than broad, flat leaves, and they are green throughout the year so they can photosynthesize even in the dead of winter. Often, taiga biomes were carved out by glaciers, leaving behind rocky ground and thin, acidic soil. Because of this, there is the least biodiversity of plants in this biome. Lichens and mosses and the occasional deciduous tree (one that loses its leaves), like oak or birch, can grow in taiga forests, but mostly you’ll see tree species like pine, hemlock, spruce, and fir.
Eastern White Pine
Image credit: arborday.org
Canadian Hemlock
Image Credit: Pahls.com
Norway spruce
Image credit: Arborday.org
Fraser Fir
Image credit: Wikipedia.com
Temperate Deciduous Forest
Image Credit: AskaBiologist.asu.edu
The temperate deciduous forest is probably the most familiar biome, since it’s the one we live in! Temperate forests have four distinct seasons and receive a moderate amount of rainfall. Because of this, there is a number of plants that call this biome home. There are mosses and lichens, grasses and flowers, and trees, both deciduous and coniferous alike, although the deciduous trees usually outnumber the conifers. Deciduous trees, like maple, oak, and beech, adapt to the changing seasons with a cycle of growing their leaves in the spring and summer to store up water and energy, and losing them in the fall and winter to minimize loss of those resources. Most plants in the temperate deciduous forest follow a similar pattern of cold weather die off and hibernation and warm weather growth and propagation (plant reproduction). The different plants you can see in a temperate forest can be seen in any New England woodland, and a few examples of plants you can see in New Hampshire forests are the ostrich fern, red maple tree, white pine, and the great white trillium.
Ostrich Fern
image credit: gardeningknowhow.com; ryan somma
Red Maple Tree
image credit: chiefrivernursery.com
Eastern White Pine
Image credit: Arborday.org
great white trillium
Image credit: U.S. Forest service; Hugh & Carol Nourse
Tropical Rainforest
Image Credit: unsplash.com
Tropical rainforests are warm and rainy all year long—yearly rainfall ranges from 80-400 inches. Rainforests are thick with trees, so to reach the sunlight, trees need to grow really tall quickly. Because of this speedy height, they often develop prop roots, which are roots that are sticking out of the soil to provide support. Trees in the rainforest don’t need to worry about staying warm or holding on to water since it’s so hot and rainy, so they have thin bark and broad leaves to drip off excess water.
Since rainforest trees are so tall, other plants in this biome have learned to adapt by needing less sunlight or using the tall trees to their advantage. One type of plant that often grows in rainforests is an epiphyte. Epiphytes grow on other plants, like on tree branches and trunks to be closer to the sun. Orchids and mosses are two example of epiphytes. Another common type of plants in the rainforest is vines. Vines have their roots in the forest floor, but grow up trees, using their strong trunks and branches as support, to get more sunlight. Since the canopy of the trees acts like an umbrella blocking out light, only about 2% of the total sunlight hits the forest floor. The plants that grow here, like mosses and ferns, have adapted to needing less light, but there isn’t too much plant growth here—most of the life is insects and fungi that get their nutrients from decaying matter. Here are a few examples of plants that live in the tropical rainforest: orchids, Venus flytraps, cacao trees, and kapok trees.
Orchid (Gastrorchis humblotii)—Since there isn’t much wind in the rainforest, plants are dependent on animals for pollination. With so many other plants around, plants try to be bigger and brighter than their neighbors to attract the attention of insects and birds.
Image Credit: skyrail.com.au; Tim Hackwood
Venus FlyTrap—Since tropical rainforests have so much plant life, it can be a battle for nutrient-rich space. To have their own space, some plants adapt to living soil that lacks nutrients by turning carnivorous, catching and digesting insects and other small animals.
Image credit: U.S. Fish and wildlife service; Jennifer Koches, USFWS
CaCao Tree
Image Credit: WXPR.org
Kapok Tree
Image Credit: Rainforest-Alliance.org; Mohsin Kazmi
Grasslands
The grasslands get their name from the abundance of grasses in this biome. Weather can be extreme in the grasslands, with cold winters with lots of snow and hot summers with fires and high winds. Due to these weather patterns, trees can’t grow in this biome—most of the precipitation is in the form of snow, so there’s not enough water for trees, and fires and wind would knock trees down. Without trees, the grasslands, also called prairie or plains, are instead filled with grasses and flowers that are pliable, so they don’t break in the wind, and have deep root systems, so they can easily grow back after stems and leaves are burned away in fires or frozen in winter. There are many species of grasses and flowers that grow in the plains, including wild oats, purple needlegrass, goldenrod, and clovers.
Wild Oats
Image Credit: agric.wa.gov.au
Purple NeedleGrass
Image Credit: UC DAvis Arboretum and Public Garden
GoldenRod
Image Credit: MinnesotaWildflowers.info
Clovers
Image credit: Old Farmers Almanac
Savanna
Savannas are similar to grasslands, with the main difference being climate—think the African savanna versus the great plains of the American west. Savannas are warm throughout the year and experience a rainy season and a dry season. The rainy season provides enough water for some trees to grow in the grassy plains, but lightning in the dry season can cause fires that keep the tree population low. The trees that can be found in the savanna, like the acacia tree or baobabs, store water to get through the dry season. Like in prairies, grasses dominate the savanna because they have deep root systems that allow the plants to grow back quickly after fires.
Rhodes Grass
Image Credit: tropicalforages.info
Acacia Tree
Image Credit: Britannica.com; EcoView/Fotolia
Lemon Grass
Image Credit: garden.lovetoknow.com
Baobab Tree
Image Credit: Askabiologist.asu.edu
Freshwater
Fresh water includes rivers, lakes, streams, and ponds. Plants that live in moving water need different adaptations than those that live in still water. In quick moving rivers and streams, plants develop roots that hold onto the solid river bottom, rather than roots that collect nutrients, and flexible stems that move with the water’s current. Other plants strongly stick to surfaces, like mosses that cling to rocks. In still water, plants don’t need to worry about being washed away, so they develop the ability to float on water, like lily pads with broad, flat leaves. Cattails, which grow on the edges of bodies of fresh water, have narrow, strap-like leaves, which easily move through water with little resistance. Other plants you could see in freshwater include algae, duckweed, and watermilfoil.
American White Water Lily—Notice that only one side of the lily’s leaves are green. The bottom of the leaf doesn’t face the sun, so no need for energy-developing chlorophyll!
Image credit: carolinanature.com
Cattails
Image Credit: britannica.com
DuckWeed
Image Credit: Gardenpool.org
Eurasian Watermilfoil—This is actually an invasive species in the U.S. If you find milfoil while boating or going for a swim, you should let a local lake association or your state’s department of natural resources know.
Image Credit: Wisconsin Department of Natural Resources
Marine or Saltwater
Rye Beach, New Hampshire
Image Credit: Katie Marinoff
Saltwater is the biggest biome in the world! Over 70% of the Earth’s surface is covered with saltwater, and over 1 million species of plants and animals have been discovered in the oceans, with scientists estimating as many as 9 million species we have yet to find. The plants that grow in the ocean, which are mostly algaes, are also some of the most important plants. Through photosynthesis, plants take in carbon dioxide and release oxygen, so all these marine plants and algaes help us breathe everyday. The group of plants that produce an estimated 50-85% of the world’s oxygen happens to be the smallest plants: phytoplankton. Beyond providing a majority of the Earth’s oxygen, phytoplankton, a type of algae, serve as the base of many foodchains, feeding the smallest fish to giant whales.
To adapt to a life in the ocean, marine plants attach themselves to rocks so they don’t get washed away or pulled to the depths of the sea where light can’t reach. They also have thick, leathery leaves that can withstand strong currents and won’t get dried out in the sun when they get washed to the shore.
Giant Kelp Forest—Giant kelp is the largest form of algae
Image Credit: National Park Service/Kelly Moore
Bladder Wrack—Notice that this seaweed has small pockets of air (hence the name Bladder wrack) which helps it float towards the surface near sunlight.
Image credit: Wikipedia; W. carter
Various Types of Phytoplankton
Image Credit: phys.org; Gabriel Yvon-Durocher
Irish Moss
Image Credit: Wikipedia
Now that we know about Earth’s biomes, we can get to our STEM Challenge! This week, we’re challenging you to flex your creativity.
You saw all the ways plants adapt to different biomes on Earth, so now imagine we’re travelling to a distant planet. What’s the planet called? What kind of environment does it have? What’s the weather like?
Now imagine we’ve landed on this planet and we’ve found a plant. How has this plant adapted to it’s habitat? How does it get it’s nutrients? How does it propagate? How does it stay safe in the planet’s weather? Create a model of your plant using any materials you have around your home—paper, fabric, recycled cans and bottles, tin foil, paint, glue, glitter, and anything else your adult gives you permission to use.
Here’s our example:
The planet Arydna is a hot and dry desert planet. Arydna was once lush and green with rivers flowing all around it, but as the dying star it’s orbiting grew to a red giant, it boiled away most of the water, leaving a rocky surface with deep ravines carved by the water that once flowed. Wind storms often blow dust around the planet, and Aryndna experiences very little rainfall, about 3 inches per year.
The life on Arydna is mostly insects and small reptiles, as well as a few cactus-like plants, including what explorers call “Devil’s Barrel.” Devil’s Barrel grows on the walls of Arydna’s ravines, protecting itself from the planets intense dust storms. It gets it’s name from its round, fleshy shape that it uses to store water from Arydna’s few rainstorm and its sticky flowers that it uses to catch and digest insects. The body of the plant clings to the rocky walls with strong, thin roots that find their way through small cracks. The flowers grow out of the ravine on long tendrils, which are pliable in the wind, waiting for bugs that are attracted to it’s sweet smell. The Devil’s Barrel propagates by growing a wide system of roots and growing new shoots from it’s root system. Here’s a model of a Devil’s Button plant:
The plant grows vertically on rocky walls
The root system
the flower petals close around insects for the plant to digest for nutrients
