Plant Biogeography Flashcards
Define biome.
A major regional area with recognisable growth forms; specific climate, vegetation, and animal life.
What are some of the major biomes that exist?
Arctic tundra, taiga and boreal forest, temperate mixed and coniferous forests, grasslands, rainforests, deciduous tropical forests and savannahs, deserts, temperate deciduous forests, and Mediterranean scrub communities.
Define ecoregion.
A major ecosystem defined by distinctive geography and receiving uniform solar radiation and moisture.
Define habitat.
The array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a specific species.
What methods do plants use to disperse their seeds?
Animals, air, water, and themselves (exploding seed pods).
What methods do plants use to adapt to water deficiency?
Improved water uptake (more/longer roots), increased water conducting capacity (more xylem or denser leaf venation), reducing transport distance (shorter internodes), reduction of transpiration (stomata, C4 or CAM photosynthesis), and water storage.
What methods do plants use to adapt to water excess?
Hydrophyte leaves; leaves with large air spaces, little xylem in vascular bundle, a thin epidermis, and stomates on the upper surface.
What methods do plants use to adapt to oligotrophic (nutrient deficiency with oxygen abundance) conditions?
Better mineral redistribution (incorporation in to extra, new organs), increased root growth or specialisation (for better absorption), excretion of chelating agents (for better mobilization of minerals), and becoming epiphytic or carnivorous.
What methods do plants use to adapt to excess nutrients?
Become calciotrophic (store calcium in soluble forms), or calciophobic (immobilise calcium as calcium oxalate crystals or bound to pectin).
What methods do plants use to adapt to metal-rich substrates?
Become metallophytic (store metals in plant tissues)
What methods do plants use to adapt to saline habitats?
Become halophytic (efficiently compartmentalize the salts or pump them back out).
What methods do plants use to adapt to shade?
Leaf shape (presence of sun and shade leaves), leaf anatomy (sun leaves are thicker with abundant chloroplasts, well developed vascular tissue; shade leaves thinner with few chloroplasts, poorly developed vascular tissue), chloroplast movement.
What methods do plants use to adapt to frost/colder conditions?
Winter dormancy, thick cuticle, epidermis and hypodermis, endodermis with Casparian strips, resin canals for protection, winter chlorophyll storage and carotenoid accumulation.
