Untitled Flashcards Set

1/17/25:

Acclimatization- a short term response of an individual to the environment

Halophyte- a plant that is adapted to salty environments, and they simply discrete salt in bulbs. Some like mangroves require salty environments.

Xerophytes- Plants that live in arid environments that like dry environments and are adapted for water retention. 

Hydrophytes- Plants that are adapted to living in water, such as lotus/lily pads. 

Plant metabolism is based on sunlight and various minerals 

Soil components: organic matter, minerals, air, water bacteria, rocks, silt, clay.

Soil originates from weathering of the environment, the breaking down of rock by wind, water, or temperature. Additionally, chemical weathering plays a role in breaking down particles into soil

Types of soil:

Igneous- weather slowly due to volcanic activity

Sedimentary- weather more easily, from glaciers, water, wind, and general weathering.

Metamorphic- weather slowly, and are created through the process of pressure and heat.

The differences between them is how the rock and minerals is broken down and what the underlying layers are. The material affects how quickly the rock is weathered.

Temperature can also affect how rocks weather, for instance, temp affects the expansion and contraction of rocks. As well as the freezing of water in splits in the rock. 

Small pieces of rock broken up and redeposited in various ways:

Glaciers

Loess (wind deposit)

Alluvial (river/stream deposits)

Lake/marine deposits

1/22/25:

Sand-small particles, held together by other materials

Silt- microscopic particles

Clay- hard to see even with a microscope

Loam is by far the most nutrient rich and most versatile soil for use by plants. 

Soil structure- arrangement of soil particles into aggregates( groups of particles)

Between these aggregates are pores, containing air or water.

The pore size depends on the soil type, and can easily be destroyed upon collection/compression.

Too much water in the pores means there is not enough oxygen available for the roots. 

If the pore size is large, then the water will drain away rapidly, leaving not enough left in the soil for the plants to absorb. Generally this includes sand.

Clay soils hold more water due to having smaller aggregates, and smaller pores, so they hold onto more water against the action of gravity. Colloid is particles in suspension that are too large to dissolve as solute. 

Field capacity- amount of water soil can hold against gravity.

Hygroscopic water- bound to soil particles, unavailable to plants

Gravitational water- drains out of soil

Capillary water- water held in pores of soil, most common water source for plants. 

Plants differ in their tolerance to acidic or alkaline soils, if they are not tolerant to the soil pH, it can kill the roots and kill off the mycorrhizae bacteria. Tolerance is usually due to the availability of other minerals. With the soil being too alkaline, there is copper, iron, and manganese being unavailable. With the soil being too acidic, nitrogen is unavailable (inhibits nitrogen fixing bacteria). 

Soil Horizons:

O=Organic Material

A=top soil

E=lower topsoil, leaching materials and organic matter

B= subsoil/clay (minerals and metal salts)

C=parent material (weathering rock)

R=Bedrock (unweathered rock)

1/27/25:

Exam 1 will be over soil, and water, possibly temp. It will be next week, check syllabus. May or may not be on wednesday 

Nutrients:

Essential elements are those that: 

• Are necessary for normal plant development and life

• Have no effective substitute

• Are used within the plant (vs outside)

Carbon, hydrogen, and oxygen are major building blocks of plants but are not always considered essential elements for plants since they are essential for all living things.

Macronutrients: nutrients that are required in large amounts for the plant to sustain itself.

Some examples of macronutrients are: nitrogen, potassium, calcium, magnesium, phosphorus, sulfur. 

Macronutrients:

Nitrogen:

 necessary for normal plant growth and reproduction. It is necessary for proteins- for cell walls, singaling, etc.

Some plants can alter the amount of nitrogen in their leaves to deter herbivores, since herbivores tend to prefer nitrogen rich leaves, the trade off for this is decrease growth and photosynthesis in the plant. 

Nitrogen also plays an essential role in photosynthesis. 

Rubisco contains a lot of nitrogen, and is the enzyme that grabs carbon dioxide from the air during sugar production. It is an incredibly important enzyme in plants, but not all plants use rubisco, there are other enzymes that can do the same job. 

Atmospheric nitrogen cannot be used by plants, so they must get their nitrogen from the soil. The way they are able to do so is through conversion of nitrogen from ammonium by soil microorganisms which are either free-living or endosymbiotic. 

Symbiotic nitrogen fixation involves a specific type of bacteria that associates with a particular plant species. These endosymbiotic have nitrogenase, and convert N2 to NH3.

Rhizobium and Fabaceae (beans), bacteria provide NH3, and the plant provides sugar, thus it is an endosymbiotic relationship. 

Anabaena and Azolla (specific fern)

Cyanobacterium anabaena provides nitrogen in freshwater systems like rice paddies. The aquatic fern azolla provides sugar, and the cyanobacterium provides nitrogen despite being an external system, meaning not on root nodules.

The rate of photosynthesis, and the symbiotic nitrogen fixation, are tied together.

Higher the nitrogen fixing rate, the higher the rate of photosynthesis, the opposite is also true.

Limits photosynthesis.

Phosphorus: 

Availability of phosphorus in soil can be as limiting as nitrogen, and is necessary for nucleic acids, proteins, and the creation of ATP and NADP+

Phosphorus is often not available in the soil - bound to soil particles.

Much of the phosphorus in an ecosystem is in the organic material, both living and decomposing, and is released by microorganisms.

Micronutrients: 

Trace elements, required in small amounts. Some examples being chlorine, iron, manganese, boron, zinc, copper, nickel, molybdenum. 

Iron:

Iron is necessary for photosynthesis since it is part of chlorophyll synthesis. It is a component of cytochromes (electron transport chain)

 Beneficial Elements: either essential only for some plant species, or not essential, but growth-stimulating. Only trace amounts are necessary. Some examples are sodium, cobalt, and silicon. 

Sodium:

Helps with osmotic balance, so it is utilized by some desert species, as well as salt marsh species, and halophytes. Essentially includes plants that live in salty environments often or constantly.

Cobalt: 

Needed by plants that have nitrogen fixing bacteria, not for the plant itself but for the bacteria. Associated with vitamin B12.

Silicon:

Utilized for components of plants that are used for herbivore defense, as well as structural components. An example being horsetail stems. 

Outlier Plants:

Carnivorous Plants: they are adapted to nutrient poor soil, and supplement themselves with prey. Get minerals from trapping insects, and use it to perform photosynthesis. Carnivorous plants evolved independently in different families. Some examples being sundew, pitcher plants, butterwort, and venus fly traps. 

Nutrient Deficiencies:

Deficiencies of essential elements lead to various symptoms.

An example is Chlorosis: where leaves lack chlorophyll, turn yellow, and become brittle.

Necrosis: death of tissue patches, often leaf tips and margins or between veins. 

Accumulation of anthocyanins (blue or red pigment), makes the leaves turn dark purple, and is due to phosphorus deficiencies. 

Excessive nutrients can also be a problem, although some plants have defenses against this such as salt glands that they secrete salt the plant cannot use.

Mobility:

Immobile elements= not able to move once incorporated into tissue. This means they cannot be moved into younger/growing tissue in the plant. It must be acquired from the soil, and if used up, will become deficient. Examples of minerals being boron, calcium, iron.

Mobile Elements= able to be moved once incorporated into tissue. So the plant can move nutrients from older to younger/growing tissue. If the soil is depleted, they can salvage nutrients from other areas of the plant. Some examples of elements being chlorine, magnesium, nitrogen, phosphorus, potassium, and sulfur. 

1/29/25:

Exam 1 will be on Wednesday possibly. Likely will be having lab stuff in the classroom.

Plants originally came from green algae before they split into plants, green algae is the closest sister taxonomic group. Plants are technically land plants (not algae), and even more technically called embryophytes. 

The types of adaptations that are necessary for plants to survive on land:

Roots

Different types of fertilization

They additionally had to adapt structurally to land

Vascular tissue

The waxy coating that protects the plant (special dermal tissue)

Stomata (pores for gas exchange)

Dermal tissue:

Epidermis- protective, one-cell thick layer that covers all plant organs. They have stomata, hairs, and glands. Prevents the plant from drying out.

Cuticle- the waxy coating on the epidermal cells. It helps slow water loss, resist bacteria, and is made of cutin, a fatty substance.

Vascular tissue: vascular tissue is not necessary for plants but is necessary for plants to grow large. The vascular tissue transports food, water, and minerals throughout the plant. Xylem is used for water transport and Phloem is used for food/sugar transport and is pressure based although still using water.

Roots:

Serve functions such as anchoring the plant, storing food and water, and roots can be used for water and mineral absorption. 

Reproductive structures:

There are multicellular reproductive structures that vary between plants. Some examples being gametangia, sporangia, embryos, and spores/seeds. 

Gametangia- structures that produce gametes and protect gametes from drying out. In mosses and ferns, water is required for fertilization, but water is less important in gymnosperm and angiosperm fertilization.

Sporangia- structures that produce spores and keeps spores from drying out. A spore itself is a haploid reproductive cell that develops into an adult without fusion with another cell. 

Embryos- land plants protect embryos within maternal tissue, and keep the embryonic plant from drying out. 

Spores- plant spores have thick walls to keep them from drying out

11/31/25:

Monday of the 10th of February is when the test is. 

Seeds- have thick walls that coat the seed for protection and it also keeps them from drying out.

Stomata- the pores on the surface of leaves and is usually on the bottom of the leaves. The stomata regulates gas exchange. The actual cells of the stomata is the guard cells, and they control the opening and closing of stomata using a water-based system that also uses potassium ions. Stomata not only keep water in, but they also regulate water movement into and through plants without costing energy. The way they do this is through transpiration via the sun.

Water moves into and through a plant due to differences in water potential. Pure water value is 0. Water moves from higher water potential to lower potential. 

Osmotic or Solute potential: usually a negative number unless it is pure water. Any solutes added makes it more negative.

Pressure Potential: It can be anything number range wise. The water in an area that restricts volume and exerts pressure on walls is called turgor pressure, meaning a positive number. Water in an open system is a negative pressure potential.

Water movement in soil:

Water moves downward in soil due to gravity.

Water can also move upward in the soil due to cohesion, capillary action, and transpiration by plants.

Capillary action- small spaces between soil particles and pull from xylem. 

Hydraulic Lift: water is pulled up from deeper places by the plant with the deepest roots. This water is then pulled up and dispersed to the roots of the plant and it’s neighbors at night. 

Hydraulic redistribution is similar to hydraulic lift just without any specific direction.

Transpiration- loss of water from a plant via water vapor, and is responsible for more than 90 percent of plant water loss, and it is via the stomata. Pro: responsible for pulling column of water through xylem. Con: too much water loss will cause guard cells to close stomata, shutting off photosynthesis.

Strategy- set of coordinated adaptive traits to compensate for water availability.

Strategies:

Mesophytes: live in moderately moist soil, only infrequent and short lived droughts for them. Any longer droughts will kill the plants. Examples being crops, forest trees, ornamental plants.

Hygrophytes: Permanently moist soil

Hydrophytes: aquatic plants

Xerophytes: live in dry soils, and either have frequent or extended droughts.

Drought escapers are short-lived: 

They live in dry environments but only grow during short rainy seasons, so they germinate, reproduce, and grow during the rainy season and die upon the season's end.

Drought deciduous: species that live in areas with prolonged dry season. During the dry season they lose their leaves and grow them back in rainy seasons. Through this method they minimize water loss by not having leaves. This isn’t necessarily for deserts only.

Some drought avoiders remain dormant when it is dry and may die back above ground, while the below ground parts remain alive. They have high growth and photosynthesis rates when active. I.e, grasses.

Other drought avoiders only grow in the areas of a habitat with the most water, for instance low areas where rain collects. 

2/3/25:

Drought tolerance-

Drought tolerant species live in very dry environments, also known as xerophytes. They still need water to survive but they have reduced leaves to reduce water loss as well as having water storage methods to survive. Additionally they have specialized versions of photosynthesis to allow plants to keep their stomata closed as much as possible to reduce water loss. They utilize C4 or CAM instead of the normal C3 method. Both C4 and CAm use different methods for fixing CO2. C4 (location), CAM (time, i.e at night). 

Flood tolerance-

Too much water can also be a problem if there is not enough oxygen for the roots the plant dies. Long term flooding can cause soil compaction, leaving less space for oxygen in the soil as well as making it difficult for roots to grow through. 

Flood tolerant plants: Have pneumatophores, which are spongy roots that extend above the surface of the water, increasing gas exchange. Additionally they provide further structure for the plant during flooding. 

Additionally, timing is a factor when it comes to plant development. Both germination and early in the growing season are important time periods for a plant to have the correct amount of water. So some species are adapted to the seasons of rainfall.

Areas can have the same amount of rainfall but different vegetation types, often due to the timing differences. Other factors could be soil type, slope, or temperature. Generally though it is reliant on the timing of the rainfall to determine the type of vegetation.

The final factor is the types of precipitation: the difference in the form of precipitation can affect the plants differently and species adapt to compensate.  Fog, hail, sleet, snow, rain, dew, and frost are all examples of precipitation. 

Rain=most common ecologically and most common precipitation. It is affected by many factors, such as topography, proximity to the ocean, temperature, and mountains.

Glaze-

2/5/25:

Exam on Monday the 10th. No class on Friday :D 

There is a bonus quiz on Blackboard. 

Notes:

Temperature: often ranked second after water for impact on plant distribution. Some argue it is #1. 

Importance of temperature: Water loss is a major concern for both extremes in temperature. With extremely high temperatures dehydration and damages down to the cellular level, essentially heat exhaustion. 

Temperature affects most plant activities: 

• Germination

• Photosynthesis

• Respiration

• Growth

• Flowering

• Fruit ripening

Most of these processes are signaled to start by temperatures. 

Thermal tolerance- range of temperatures a plant can tolerate without damage. 

• Activity Limit=range plant can function normally. 

• Lethal limit=range plant can remain alive.

Temperature Stress- low or high temps that cause injury

• Frost injury

• Heat Injury

Temps too cold:

• Metabolism slows down

• Membrane less elastic

• Ice crystals form in cells

Temps too High: 

• Proteins denatured

• Membranes damaged

Energy Balance:

Plant temperature is determined by energy balance, energy inputs + energy loss (+energy storage)

Energy Balance=Radiant heat- sensible heat- latent heat = 0 

Usually also involves metabolic heat and heat storage, but this does not really apply to plant leaves. 

Energy Transfer:

Radiation= energy from the sun

There are different types of wavelengths: Shorter- higher energy, longer- lower energy. Also brings light

Applies to fire as well. 

Conduction= direct transfer of heat from warmer to colder objects, important in soil. 

Convection=transfer of energy by fluid (air or water). It is faster than conduction. Cold wind leads to heat loss and warm wind leads to heat gain. 

Sensible heat is a combination of conduction and convection.

Some animals avoid excessive heat loss due to convection with fur or feathers, but although plants have little hairs, it cannot avoid excessive heat with these hairs.

Boundary layer= layer of still fluid around a leaf, resistant to heat transfer. The thicker the layer the less heat transfer.

Wind speed + size/shape of leaf

Higher wind removes the layer of leaves. Larger round more whole leaves have larger layers. 

Transpiration also causes energy transfer. In a process called latent heat exchange, which means all the heat lost during evaporation from the surface of the plant. 

Temperature Control:

Plants need to maintain their leaves within a range of temperatures to balance the radiant energy from the sun and the heat loss rate.

Leaf anatomy plays a role in this. Larger leaves with higher boundary layers are often warmer or cooler than air temp. Smaller or dissected leaves usually are closer to air temp. 

So what happens when a plant with large leaves is in bright sun, little wind, and dry soil? There is high radiant energy input, little or no convective loss, temp higher than surrounding air. 

End Result: more than likely the plant will still not open the stomata, and will take heat damage rather than lose water. 

Change necessary for life: add even a slight breeze and adequate water the plant will be fine. 

Same scenario with a small leaf? 

Still high radiant energy, smaller boundary layer so more convective loss. The leaves will tend to stay closer to the air temperature. 

Controlling transpiration rate is key to controlling leaf temperature. 

For instance modified leaves of cacti are adapted for minimizing transpiration and heat absorption

Dissected leaves - decreased boundary layer and is more adapted to the specific range of temperature in the region.

Some plants can somewhat control the level of radiant heat:
This is done by the steep angle of leaves= less exposure to sun

Leaf hairs or super shiny wax= reflective 

Grasses and relatives can roll their  leaves into cylinders, which minimizes the boundary layer and radiant heat input. While also minimizing water loss. 

Bulliform cells= cells on either side of the main vein that partly collapse, causing the leaf to roll.

Importance of temp:

Extreme temperatures affect global distribution of species, and climate change is altering these boundaries.

Plants can adapt in various ways, becoming increasingly cold or heat tolerant. Such as changes in morphology, metabolism, and on a cellular level. 

Temperature is not affecting plants alone though because water, soil, light etc. is involved as well.