Biodiversity Flashcards
Genetic Biodiversity
Variety of alleles/genes in a population, relates to a population’s ability to adapt, high genetic diversity is tied to species resilience
Species Biodiversity
Variety of life in a given area, the most noticeable, measurable
Ecosystem Biodiversity
Variety of habitats, communities, and ecological processes within a given area
Influences on Species Biodiversity
Type of habitat, location of habitat, disturbance
Dynamic Equilibrium Model
Disturbance can increase species diversity by removing a dominant species of competition, or it can lower diversity through harming life
Species Evenness
How evenly species are distributed across their ecosystems // higher species evenness results from species having similar relative abundances
Species Richness
Total number of species in a community (S)
Pleustic
Air/water interface, e.g. man-of-war that lives on the surface
Pelagic
Water column, e.g. whales, squids
Benthic
Bottom surface of waters, e.g. clams and oysters (zoobenthos) and e.g. sea grass (phytobenthos)
Vertical Location Classifications
Categorize species based on location in water column, can change over lifetime, is not exclusive
Nekton
Swimming
Plankton
Drifting
Motility Classifications
Whether swimming (nekton) or depending on currents (plankton)
Micro to Meso to Macro to Mega Plankton
less than 0.2 cm, between 0.2 and 2 cm, between 2 and 20 cm, over 20 cm (e.g. man-of-war is megaplankton)
Phyto and Zoo Plankton
autotrophs and heterotrophs
Holo and Mero Plankton
holo, entire lives as plankton; mero, part of lives as plankton (usually in larvae stage)
Single-Celled Organisms
Autotrophs and Decomposers, play very important roles in ecosystems // Include all three domains, bacteria, archaea, and eukaryotes (plant, fungi, protists) // Can survive extremes // Very diverse group
Bacteria
Prokaryotes, ubiquitous and very numerous // Autotrophic, primary producers, most notably cyanobacteria like blue-green algae and also chemolithotrophic bacteria (that use chemicals from hydrothermal vents) // Heterotrophic bacteria like decomposers
Archaea
“Tiny and tough” // Often live at the extremes, extremeophiles, tend to be acidic- alkanitic- and salinity- tolerant // Prokaryotes // Found in almost every habitat
Protists
Eukaryotes // Classified similar to the “higher kingdoms,” animal-like or plant-like // Salt and fresh water, plankton (zoo- ciliates, amoeba, foraminiferans) (phyto- euglena) // Autotrophic or heterotrophic // Diatoms
Aquatic Fungi
Heterotrophic eukaryotes that are unicellular or filament-like, decomposers (especially of plant matter), less common than in terrestrial habitats
Diatoms
Protists (eukaryotes) that produce 20% of atmospheric oxygen, most common form of algae and phytoplankton, around 20% of atmospheric oxygen, have silica shells, and are unicellular but form colonies
Aquatic Plants
Micro- and Macro- phytes // Can be emerged (mangrove trees), submerged (kelp, moss, sea grass), or floating (water lilies) // Provide cover and food for animals, and are primary producers // Can be mosses (non-vascular that reproduce by spores), angiosperms (flowering plants, often only emerged or floating; yet sea grass is a true submerged angiosperm), or algae (seaweeds like kelp, and algae you can only see in mass colonies)
Aquatic Animals
Multicellular, eukaryotic, all move by means of muscles, high degree of cell-specialization, heterotrophic, between 35-40 phyla, tons of diversity with nekton, zooplankton, and zoobenthos // Often defined by vertebrate or invertebrate
Invertebrates
Most are obligate aquatic animals (like crabs), or semi-aquatic (like mosquitos for part of their life cycle), variety of locomotion (walk, swim, float, sessile [e.g. sea anemone]), include sponges, cnidarians, mollusks, arthropods (insects and crustaceans), echinoderms, and tunicates
Sponges
Porifera, benthic, freshwater and marine, nektonic larvae, sessile adults // one of the first to branch off on the cladograms from the beginning of life, no true organs or tissue
Cnidarians
Radially symmetrical, have cells that sting (cnidocytes), freshwater and marine // includes anemones (benthic, sessile as adults), jellyfish (found throughout water column, pelagic or pleustic), corals (benthic, sessile as adults), sinophores
Mollusks
Have a head-foot complex (bilaterally symmetrical) and a mantle (soft part of body to protect) that usually secretes a calcium carbonate shell // second largest phylum of invertebrates both living and in fossil record, largest marine phylum in diversity
Arthropods
Segmented bodies with jointed appendages, usually compound eyes, external cuticle of chitin, exoskeleton // all engage in sexual reproduction, all undergo metamorphosis and molting // freshwater and marine, the largest phylum of invertebrates, semi-aquatic or fully aquatic
Echinoderms
Bilateral or radial symmetry, benthic as adults, only marine, have an endoskeleton, can reproduce asexually or sexually, can regrow limbs/extremities
Tunicates
Benthic as adults, marine only, sexual reproduction and through budding, doral nerve cord as larvae
Vertebrates
May be obligate aquatic animals or semi-aquatic, variety of locomotion (walk, swim, float, fly), in rivers lakes, and oceans, can be mammals, amphibians, birds, reptiles, or fish
Fish
Skeletal, and gill-bearing, over 34,000 species known, most diverse aquatic vertebrate taxon, can be jawless, cartilaginous, or fin // cartilaginous fish (sharks, skates, and rays) and bony fish (which use a rigid skeleton for muscular attachment and contraction)
Jawless
Lack paired fins, no jaw, e.g. lampreys
Cartilaginous
Sharks, scapes, and rays, Scaleless, made of cartilage rather than bone
Fin Fish
Ray-finned (most common) or Lobe-finned (most are extinct)
Amphibians
Only in freshwater systems, most start lives as obligate aquatic organisms complete with gills before metamorphosing into adult form with lungs for air // Includes frogs (90% of amphibian diversity) and salamanders
Reptiles
A lot of extinct marine species, in freshwater or marine systems, semi-aquatic or obligate aquatic animals, do not have larval aquatic stage, often lay eggs on land (yet sea snakes can give birth to live young in water), shed skin throughout year
Birds
Freshwater and marine systems, some more aquatic or terrestrial, depends a lot on species // Include seabirds (feed at sea), shorebirds, waders (cool adaptations like long legs, necks, and beaks to keep feathers dry; herons, egrets, flamingos), waterfowl (duck, geese, swan, magpie, webbed feet, sexually antagonistic evolution, had waterfowl at time of dinosaurs)
Mammals
Freshwater and marine systems, often presence of hair or fur and live young that they nurse, take up 10% of marine primary production // marine mammals, hippopotami, rodents, shrews, otters and minks, platypus
Relative Abundance
How much of a specific species contributes to the total number of species in a community
Simpson’s Diversity Index
One way to measure species diversity, measures diversity through probability, the probability that two individuals from a random sample will belong to the same species
Traits
Specific characteristics of an individual, can affect the ability of a species to thrive in a habitat // Can be biological (morphology, physiology, life history) or ecological (habitat preference) // K (like humans) and r (like mice) species exist in suites
Adaptation
How an organism becomes best suited to its habitat, can take multiple generations // can be physiological, morphological, or behavioral
Aquatic Biodiversity
Much higher in the variety of phyla and classes
Biodiversity Levels
Point, habitat, or regional
Functional Diversity
Defined by the number of functional groups, such as deposit feeders, scavengers, pioneer encrusting suspension feeders
Redundancy Hypothesis
An increasing number of species increases ecosystem functionality proportionally less as the number of species approaches a point where further additions have no net effect
Ecosystem Functionality
This is unlikely to be affected by the loss of one or two species in species-rich systems
Species-Poor Systems
Expected to be the most vulnerable to external forcing factors, where the loss of one or two species would have a greater proportionate effect on ecosystem functioning
Scale Effects
The spatial and temporal scales at which biodiversity is sampled greatly affect the results
Relative Abundance
How much of a specific species contributes to the total number of species in a community
What does Simpson’s Diversity Index consider?
Both species richness and relative abundance to measure species diversity
