(finished) Botany - Ecology/Cycles

Why is plant diversity important?

• Can support wide variety of pollinators and beneficial wildlife, herbivores, and insects

• Different root structures/nutritional needs=better soil health/erosion prevention

• For human global food supply, pharmaceuticals, and tourism

• One threat won’t wipe out the whole area

Plant competition

When neighboring plants vie for limited resources e.g. light, water, nutrients, germination sites, pollinators, or growth space.
e.g. allelopathy *where plants release allelochemicals” to inhibit the growth, germination, or reproduction of neighboring plants) or faster growth (takes space/resources)

Plant biochemistry

The scientific study of chemical processes and molecular compounds that occur inside plants.

Botany

Plant

Definitions?

Botany: The scientific study of plants

Plant: Any multicellular, eukaryotic, usually photosynthetic life-form in the kingdom Plantae

Plants in: Carbon cycle

Photosynthesis (see general flashcards; takes in CO2) and cellular respiration (equation exact opposite of photosynthesis: C6H12O6 (aka glucose) + 6O2 → 6CO2 + 6H2O. Used to turn glucose into energy (ATP) in mitochondria, with CO2 byproduct.)

• Transfers C via food web eating

• Decomposition of plants return C into soil or the atmosphere

Plants in: Water cycle

• Absorbs groundwater and returns it as vapor via transpiration

• Uses water for photosynthesis

• Prevents runoff (less soil erosion)

• Allows better infiltration of water back to aquifers by breaking up soil via roots

Plants in: Phosphorus cycle

Plants take up inorganic phosphate from the soil, and may then be eaten.
Once inside the plant or animal, the phosphate is incorporated into organic molecules e.g. DNA. During decomp, the organic phosphate is returned to the soil, and bacteria/fungi make it available to plants/inorganic again via mineralization.

Plants in: Nitrogen cycle

• Legumes have nodules that hold nitrogen-fixing bacteria (that turn atmospheric N2 into usable NH3); Nitrogen fixation

• When plants are decomposed by bacteria/fungi, ammonia (NH3) and ammonium (NH4+) is released, which plants can use; ammonification

Plants in: Sulfur cycle

• Plants take in SO4 in the soil that entered via rain, rock erosion, etc

  • When they decompose, release H2 4TH (hydrogen sulfide) gas.

Roles of plant in environmental management (5)

• Carbon sequestration

• Temperature control via shade and transpiration

• Soil erosion control

• Runoff control and filtration

• Flood reduction via better aquifer recharging

Ecological succession

Pioneer stage: Hardy pioneer species e.g. lichen or grasses grow in the nutrient-poor conditions. By breaking down rocks/contributing organic matter, makes soil.

Intermediate stage: Seral community forms. Larger plants e.g. shrubs, small trees, and herbaceous plants grow/contribute more shade/organic matter, improving soil. Attracts animals (nutrients cycling, seed dispersal)

Climax stage: Self-sustaining ecosystem with diverse flora/fauna; large trees e.g. hickories, oaks

Secondary ecological succession

Primary succession, except it happened after a disturbance e.g. natural disaster or human activity set it back some steps.

Pioneer stage: Pioneer species prevent erosion of existing soil/stabilize and contribute to it.