Tree and Soils relationship status: its complicated
Shelby Finks
11/27/2018
NRES 301 – Tree Biology
What is so important about soil? Or the surfaces trees grow from? As you can see from the Figures below trees grow in some peculiar surfaces. Surfaces like; buildings, water, small pots, and even on a ledge of a cliff! How is this possible? Why would a tree pick that surface to live? According the Soil Management for Urban Trees, trees need soil for uptake of water and minerals and for physical support. In addition, soil is essential for the trees health and every day functions (1). So how are the trees below able to thrive with no or little soil? To answer these questions we will look at Soil and its properties, and roots system.
11/27/2018
NRES 301 – Tree Biology
What is so important about soil? Or the surfaces trees grow from? As you can see from the Figures below trees grow in some peculiar surfaces. Surfaces like; buildings, water, small pots, and even on a ledge of a cliff! How is this possible? Why would a tree pick that surface to live? According the Soil Management for Urban Trees, trees need soil for uptake of water and minerals and for physical support. In addition, soil is essential for the trees health and every day functions (1). So how are the trees below able to thrive with no or little soil? To answer these questions we will look at Soil and its properties, and roots system.
Figure 1. Bonsai tree. Bonsai trees need little soil to survive. (2)
Figure 2. Mangrove forest in Loxahatchee, Florida. (3)
Figure 3. Tree growing off a cliff. (4)
Figure 4. Giant tree growing from the Ta Prohm temple's wall. (5)
Soil
When one thinks of soil, one would think of a big bag of “dirt” to use in a home garden or the dirt found in a bare crop field. However, soil can take on many shapes and forms that can enhance plant growth. That is why some trees (see images above) can live in strange surfaces. These surfaces include soil that have a particular; physical properties, microbes, and minerals that can enhance tree growth (1).
When it comes to soil, texture, is the different sizes of soil particles (1). Sizes of particles can affect the soils structure, profile, consistence and compactions (1). Clay, silt, sand, and gravel are different types of soil texture that trees can grow from (1).Figure 3 is a great example of a soil that has the texture of gravel. Gravel is found in most natural environments and have small soil particles and can hold some water and nutrients (1). How much nutrients gravel soil can hold depends on its’s type of soil structure (1). Soil structure is different from soil texture. Soil structure is how soil forms after weathering and other biological forces (1). Under these forces soil can expand, contract, dry, freeze and thaw (1). Understanding the soil structure and texture can tell us how well trees will drain or hold water and nutrients for growth (1). Many arborist and scientist look at these characteristics of soil to help identify the capabilities of growth of the tree (1).
One thing to remember that soil is not just “dirt” (1). Soil is made up of minerals, organic compounds, and living biological elements (1). Soil that are classified as, healthy, should have a community or organisms that create a food web (1).For example, earthworms are decomposers, that help trees growth by breaking down any decay or feces so, the tree can take up the nutrients by the roots and atmosphere (1). The flow of energy matter is cycled through the trees, microorganisms, bacteria, and decomposers (1). Even though some surfaces do not seem like it can support healthy soil, like the examples above, remember that soil can take many forms with supportive minerals, organic compounds and living biological elements.
Minerals nutrients are small but have a big impact on tree growth (6). There are two types of mineral nutrients; Macronutrient and micronutrient (6). The macronutrients for a tree are nutrients that are essential for growth, and include; nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur (6). Micronutrients are only needed at small amounts and include; iron, manganese, zinc, copper, boron, molybdenum, chlorine, and nickel (6). If a tree does not have enough macronutrients in the soil it can affect the growth and physiological processes (6). For example if a tree has a deficiency in nitrogen the tree will grow slowly and have leaf abscission (6).
Roots
The soil holds all the nutrients and minerals the tree needs to grow (6). The tree root system allows the tree to extract the nutrients out from the soil and send it to various parts of the tree (6). Roots not only absorb the minerals and nutrients it also anchors the tree into place, storage of food, and help form certain growth hormones (6). But why would a tree choose a surface where the roots would have a hard time anchoring in and provide nutrients?
Often trees find a surface that is most suitable at that time however, biological disturbances occur or any injuries occur and can change the texture and structure soil. Trees roots adapt to this disturbances or injuries and create a different kind of roots (6). They are called adventitious roots (6). They develop from the main stem, branch or other tissues and bend down towards the soil (6). Adventitious roots can create stilts (6). Which means these roots develop outside of the soil and create a system that helps obtain nutrients from the soil (6). The mangrove tree is a great example of having adventitious stilt roots (6; 3). Most of trees that have this advantage are found in swamps, fresh water, and rain forest (6). This kind root adaptation is a great way for trees to ensure a long life and healthy growth.
Mycorrhizas is an another way trees can ensure a long life and healthy growth (6). Mycorrhizas is a type of fungus that assist the tree absorb more nutrients and water (6). Not only do they help bring in more nutrients but they can act as a protector against water stress (drought, flooding), toxic metals, and some diseases (6). In return the tree provides mycorrhiza with food (6). This relationship is called symbiotic; where two species work together for mutual benefits (6). It has been found that trees can grow without mycorrhizas but, trees grow better with them (6).
Trees seem to defy everything that we know that would make it healthy and grow successfully in its environment. Trees can grow on buildings, rocks, water and in small areas. As we look at these surfaces one would think, there’s no way! Is that is possible? After everything we have been taught, since elementary school, trees need soil to survive. However, the truth is, those strange surfaces have soil that is suitable for growth. Keeping in mind, that specific species of trees, flourish better in environments that are more suited for that tree; a mangrove tree would not be seen in the desert. In addition trees overtime can adapt to their environment and create systems to ensure growth. These trees might have a difficult time with growth or may eventually die. On contrary, if tree has soil that provides great texture, structure, nutrients, with roots that are adaptive, the tree will grow. Yet, what does this all mean? Why is this important for us to know? It is important for arborist to understand the systems so urban cities can have trees that will thrive off of little or no soil (1). With this knowledge arborist are able to engineer artificial soil called Amsterdam soil (1). Amsterdam soil is made of a mixture of materials and some volcanic ash (1). Amsterdam soil creates soil that is able to expand for roots underneath pavements in the city (1). This will help city trees improve their growth and enable trees grow in difficult sites, just like the trees in the figures above (1). Without tree biology we would be unable to have cities with no trees! No one would have that favorite childhood tree in your own backyard! With this in mind I will end this with a quote from Albert Einstein;
“It is, in fact, nothing short of a miracle that the modern methods of instruction have not yet entirely strangled the holy curiosity of inquiry; for this delicate little plant, aside from stimulation, stands mainly in need of freedom; without this it goes to wrack and ruin without fail. It is a very grave mistake to think that the enjoyment of seeing and searching can be promoted by means of coercion and a sense of duty (7)”
When one thinks of soil, one would think of a big bag of “dirt” to use in a home garden or the dirt found in a bare crop field. However, soil can take on many shapes and forms that can enhance plant growth. That is why some trees (see images above) can live in strange surfaces. These surfaces include soil that have a particular; physical properties, microbes, and minerals that can enhance tree growth (1).
When it comes to soil, texture, is the different sizes of soil particles (1). Sizes of particles can affect the soils structure, profile, consistence and compactions (1). Clay, silt, sand, and gravel are different types of soil texture that trees can grow from (1).Figure 3 is a great example of a soil that has the texture of gravel. Gravel is found in most natural environments and have small soil particles and can hold some water and nutrients (1). How much nutrients gravel soil can hold depends on its’s type of soil structure (1). Soil structure is different from soil texture. Soil structure is how soil forms after weathering and other biological forces (1). Under these forces soil can expand, contract, dry, freeze and thaw (1). Understanding the soil structure and texture can tell us how well trees will drain or hold water and nutrients for growth (1). Many arborist and scientist look at these characteristics of soil to help identify the capabilities of growth of the tree (1).
One thing to remember that soil is not just “dirt” (1). Soil is made up of minerals, organic compounds, and living biological elements (1). Soil that are classified as, healthy, should have a community or organisms that create a food web (1).For example, earthworms are decomposers, that help trees growth by breaking down any decay or feces so, the tree can take up the nutrients by the roots and atmosphere (1). The flow of energy matter is cycled through the trees, microorganisms, bacteria, and decomposers (1). Even though some surfaces do not seem like it can support healthy soil, like the examples above, remember that soil can take many forms with supportive minerals, organic compounds and living biological elements.
Minerals nutrients are small but have a big impact on tree growth (6). There are two types of mineral nutrients; Macronutrient and micronutrient (6). The macronutrients for a tree are nutrients that are essential for growth, and include; nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur (6). Micronutrients are only needed at small amounts and include; iron, manganese, zinc, copper, boron, molybdenum, chlorine, and nickel (6). If a tree does not have enough macronutrients in the soil it can affect the growth and physiological processes (6). For example if a tree has a deficiency in nitrogen the tree will grow slowly and have leaf abscission (6).
Roots
The soil holds all the nutrients and minerals the tree needs to grow (6). The tree root system allows the tree to extract the nutrients out from the soil and send it to various parts of the tree (6). Roots not only absorb the minerals and nutrients it also anchors the tree into place, storage of food, and help form certain growth hormones (6). But why would a tree choose a surface where the roots would have a hard time anchoring in and provide nutrients?
Often trees find a surface that is most suitable at that time however, biological disturbances occur or any injuries occur and can change the texture and structure soil. Trees roots adapt to this disturbances or injuries and create a different kind of roots (6). They are called adventitious roots (6). They develop from the main stem, branch or other tissues and bend down towards the soil (6). Adventitious roots can create stilts (6). Which means these roots develop outside of the soil and create a system that helps obtain nutrients from the soil (6). The mangrove tree is a great example of having adventitious stilt roots (6; 3). Most of trees that have this advantage are found in swamps, fresh water, and rain forest (6). This kind root adaptation is a great way for trees to ensure a long life and healthy growth.
Mycorrhizas is an another way trees can ensure a long life and healthy growth (6). Mycorrhizas is a type of fungus that assist the tree absorb more nutrients and water (6). Not only do they help bring in more nutrients but they can act as a protector against water stress (drought, flooding), toxic metals, and some diseases (6). In return the tree provides mycorrhiza with food (6). This relationship is called symbiotic; where two species work together for mutual benefits (6). It has been found that trees can grow without mycorrhizas but, trees grow better with them (6).
Trees seem to defy everything that we know that would make it healthy and grow successfully in its environment. Trees can grow on buildings, rocks, water and in small areas. As we look at these surfaces one would think, there’s no way! Is that is possible? After everything we have been taught, since elementary school, trees need soil to survive. However, the truth is, those strange surfaces have soil that is suitable for growth. Keeping in mind, that specific species of trees, flourish better in environments that are more suited for that tree; a mangrove tree would not be seen in the desert. In addition trees overtime can adapt to their environment and create systems to ensure growth. These trees might have a difficult time with growth or may eventually die. On contrary, if tree has soil that provides great texture, structure, nutrients, with roots that are adaptive, the tree will grow. Yet, what does this all mean? Why is this important for us to know? It is important for arborist to understand the systems so urban cities can have trees that will thrive off of little or no soil (1). With this knowledge arborist are able to engineer artificial soil called Amsterdam soil (1). Amsterdam soil is made of a mixture of materials and some volcanic ash (1). Amsterdam soil creates soil that is able to expand for roots underneath pavements in the city (1). This will help city trees improve their growth and enable trees grow in difficult sites, just like the trees in the figures above (1). Without tree biology we would be unable to have cities with no trees! No one would have that favorite childhood tree in your own backyard! With this in mind I will end this with a quote from Albert Einstein;
“It is, in fact, nothing short of a miracle that the modern methods of instruction have not yet entirely strangled the holy curiosity of inquiry; for this delicate little plant, aside from stimulation, stands mainly in need of freedom; without this it goes to wrack and ruin without fail. It is a very grave mistake to think that the enjoyment of seeing and searching can be promoted by means of coercion and a sense of duty (7)”
Works Cited
1. Arboriculture, International Society of. Soil Management for Ubran Trees.
2. wagners greenhouses and garnden center. [Online] [Cited: 11 27, 2018.] https://www.wagnergreenhouses.com/garden-center/plant-selection/bonsai-trees/.
3. Service, National Ocean. What is a "mangrove" forest? [Online] [Cited: 11 27, 2018.] https://oceanservice.noaa.gov/facts/mangroves.html.
4. Redit . [Online] [Cited: 11 27, 2018.] https://www.reddit.com/r/interestingasfuck/comments/71frrb/tree_growing_on_the_side_of_a_cliff/.
5. Photo: “The giant Spung tree roots embraced the Ta Prohm temple's wall.”. [Online] [Cited: 11 27, 2018.] https://www.tripadvisor.ie/LocationPhotoDirectLink-g297390-d2181240-i43456000-Cambodian_Trails_Private_Guided_Angkor_Tour-Siem_Reap_Siem_Reap_Province.html.
6. Pallardy, Stephen G. Physiology of Woody Plants. s.l. : Academic Press Publication, 2008.
7. Einstein, Albert. Great Educational Quotes. [Online] [Cited: 11 27, 2018.] https://learningrevolution.com/page/great-educational-quotes.
8. Urban, James. Up by Roots Healthy Soils and Tress in the Built Environment. International Society of Arboriculture, 2008. s.l. : International Society of Arboriculture, 2008.
9. Dr Gary W. Watson, Dr. Dan Neely. The landscape Below the ground. s.l. : The International Society of Arboriculture, 1993.
