Soils: 2_Soil Ecology and Soil Health

Question 1

What are agroecosystems?

Answer 1

Ecosystems that are managed to produce agricultural products.

Question 2

What is the apoplastic pathway?

Answer 2

In plants, the movement of water and solutes through the cell walls and intercellular spaces, outside of the cell membranes.

Question 3

What are aquaporins?

Answer 3

Water-specific protein channels embedded in cell membranes that facilitate the transport of water.

Question 4

What is air seeding?

Answer 4

The process by which air is pulled from an embolized conduit into a functional, water-filled conduit across a pit membrane when tension in the water column exceeds a critical threshold, leading to embolism formation.

Question 5

What is biochar?

Answer 5

A carbon-negative soil amendment produced from the pyrolysis of biomass, shown to improve soil health and fertility.

Question 6

What is cavitation?

Answer 6

The breaking of the continuous water column in xylem conduits due to excessive tension.

Question 7

What is the cohesion-tension (C-T) mechanism?

Answer 7

The primary mechanism driving water movement in plants, relying on the cohesive forces between water molecules and the tension generated by transpiration.

Question 8

What are contaminated sites?

Answer 8

Areas of land where the soil and/or groundwater contain hazardous substances at concentrations above regulatory limits, posing risks to human health and the environment.

Question 9

What are ecosystem services?

Answer 9

The benefits that humans receive from ecosystems, such as clean air and water, pollination, and climate regulation.

Question 10

What is embolism?

Answer 10

A gas bubble that forms in a xylem conduit after cavitation, blocking the flow of water.

Question 11

What is the endodermis?

Answer 11

A layer of cells in the plant root that surrounds the vascular tissue (xylem and phloem) and regulates the movement of substances into the stele.

Question 12

What are fossorial animals?

Answer 12

Animals that are adapted for digging and living underground.

Question 13

What is guttation?

Answer 13

The exudation of water droplets from the margins of leaves, often seen in the morning when transpiration rates are low and root pressure is high.

Question 14

What is hydrotropism?

Answer 14

The growth of plant roots towards water.

Question 15

What are mycorrhizal fungi?

Answer 15

Fungi that form symbiotic relationships with plant roots, enhancing nutrient and water uptake for the plant while the fungi receive carbohydrates.

Question 16

What is nutrient cycling?

Answer 16

The natural processes by which nutrients are exchanged between living organisms and the environment.

Question 17

What is osmosis?

Answer 17

The diffusion of water across a semipermeable membrane from an area of high water potential to an area of low water potential.

Question 18

What are parenchyma cells?

Answer 18

Living, metabolically active cells found in xylem tissue that are important for storage, conduit maintenance, and radial transport.

Question 19

What are persistent organic pollutants (POPs)?

Answer 19

Organic compounds that are resistant to environmental degradation and can accumulate in the food chain.

Question 20

What is a petiole?

Answer 20

The stalk that attaches a leaf to a stem.

Question 21

What are pit membranes?

Answer 21

Modified primary cell walls and middle lamellae found within pits in xylem conduits, allowing water passage while limiting the spread of air bubbles and pathogens.

Question 22

What are pits?

Answer 22

Cavities in the thick secondary cell walls of xylem conduits that allow for water movement between adjacent conduits.

Question 23

What is programmed cell death?

Answer 23

An ordered process of self-destruction in cells, such as the formation of xylem conduits.

Question 24

What are provisioning soil ecosystem services?

Answer 24

Benefits from soil that provide tangible resources, such as food, fiber, and timber.

Question 25

What are regulating soil ecosystem services?

Answer 25

Benefits from soil that regulate environmental processes, such as water filtration, climate regulation, and flood control.

Question 26

What are resource recovery pathways?

Answer 26

Methods to extract valuable resources, such as critical minerals, from contaminated materials like industrial waste.

Question 27

What is root pressure?

Answer 27

Positive pressure generated in the roots that can push water up the xylem, especially when transpiration is low.

Question 28

What is soil carbon sequestration?

Answer 28

The process by which carbon dioxide (CO2) is removed from the atmosphere and stored in the soil, primarily in the form of soil organic matter.

Question 29

What is soil degradation?

Answer 29

The decline in soil quality and health due to various factors, including erosion, loss of organic matter, salinization, and pollution.

Question 30

What is soil organic matter (SOM)?

Answer 30

The organic component of soil, consisting of decomposing plant and animal residues, microorganisms, and their by-products.

Question 31

What is soil pollution?

Answer 31

The contamination of soil with harmful substances, such as heavy metals, pesticides, and organic pollutants.

Question 32

What is the soil plant atmosphere continuum (SPAC)?

Answer 32

The continuous pathway for water movement from the soil, through the plant, and into the atmosphere.

Question 33

What are stomata?

Answer 33

Small pores on the surface of plant leaves, typically on the underside, that regulate gas exchange (CO2 uptake and water vapor release).

Question 34

What is suberin?

Answer 34

A waxy, waterproof substance found in plant cell walls, such as in the Casparian strip of the endodermis, that blocks the apoplastic pathway.

Question 35

What are supporting soil ecosystem services?

Answer 35

Fundamental services provided by soil that are essential for other ecosystem services, such as providing habitat for biodiversity and physical support for plants.

Question 36

What is the Sustainable Canadian Agricultural Partnership (Sustainable CAP)?

Answer 36

A five-year funding agreement between the federal, provincial, and territorial governments in Canada for cost-shared agricultural initiatives, including those related to soil health.

Question 37

What are tracheids?

Answer 37

Smaller conducting elements in xylem tissue that taper at each end.

Question 38

What is transpiration?

Answer 38

The process by which water vapor is released from plants into the atmosphere, primarily through stomata.

Question 39

What are tyloses?

Answer 39

Outgrowths from living plant cells that can block xylem conduits in response to wounding or pathogen invasion.

Question 40

What are vascular plants?

Answer 40

Plants that have specialized tissues (xylem and phloem) for transporting water, nutrients, and sugars throughout the plant.

Question 41

What are vessels?

Answer 41

Larger conducting elements in xylem tissue made up of vessel elements stacked end-to-end, forming continuous open tubes.

Question 42

What is water potential?

Answer 42

The potential energy of water per unit volume, which determines the direction of water movement.

Question 43

What is xylem?

Answer 43

The vascular tissue in plants responsible for transporting water and dissolved nutrients from the roots to the rest of the plant.