Ecology-plants

• physicochemical features of the environment
• may be altered by other organisms
• never consumed

• forms of energy, chemical compounds
• consumed

carbon dioxide + water + light --> sugar + oxygen

• amount of C fixed/ unit time
• varies depending on light and environment
• quality: wavelengths present
• intensity

• quality: light varies depending on environment which plants must make due
• intensity: more light increases photosynthetic rate (increases till CO2 is limited)

• upright and many layers allows for a lot of sun capture for sun plants
• single layer and very horizontal allows for maximum light capture for shade plants

need to conduct aerobic respiration, never limiting since they produce it (except for maybe roots)

• 400pm in atmosphere, not limited
• enters leaf thru stomates
• diffuses thru intercellular spaces in leaf then into photosynthesizing cells
• need for feeding

• potentially limiting resource
• water can evaporate out of leaf cells (thru stomata)

balence of CO2 entry and water loss thru stomata

• need to minimize water loss but maximize CO2 intake
• can survive drought conditions

ex. waxy cuticle, upright leaf, hairy leaves, stomata on underside, deep root systems, organs for water storage

being physiologically active during dry times

• live thru dry times as seeds rather than photosynthesizing individuals
• germination triggered when water is available
• becomes seed before drought begins

leaves lose a lot of water, so leaves are lost

light, O2, CO2, water, nutrients, space, food

most common limiting nutrient

• N2 is dominant, but still limiting since plants can only use ammonium (NH4) and nitrate (NO3)
• Nitrogen must be fixed
• abiotic: lightening
• *biological*: N-fixing bacteria (free living or symbiotic), uses enzymes

carnivorous plants found most often in low N areas since insects bodies have N

humans fixing N: fossil fuels, nitrogen fixing crops, fertilizer

• he nitrogen fixation reaction of nitrogen gas and hydrogen gas to make ammonia
• energy inputs required, fossil fuel consumption

• limiting resource
• from breaking down of rocks and soil and decomposition of particles from elsewhere
• exists as PO4
• plants associate with mycorrhizae (fungus) to increase access to P

• in water plants:
• P is limiting because it causes algal growth, makes insoluble compounds
• algae dies, bacteria and fungi break it down, use up O2 in water for respiration

• space: for growth, access resources, limiting on plant survival
• food: parasitic plants (using roots to tap into another plant for food)