Biogeography Flashcards
What defines a species?
A group of individuals that has the potential to produce fertile offspring and cannot reproduce with other groups
Genetic diversity?
Variation in individuals genetics between and within populations
Higher potential to survive long term as they have higher resilience
Ecosystem/ecological diversity?
the variety of ecosystems within the biosphere
Variety in flora and fauna
Species diversity?
the variety of species in a given area.
Why is biodiversity so important?
Different reasons. Insures carbon storage
as well as water resource and pollination for food production can be provided
Tropical biomes
Tropical forests = warm and humid all year around, equal temperature and a lot of energy and water. Nutrients cannot enter deeply in soil. Soil fertility stays in top layer. Big animals are high up in the trees competing for sunlight for photosynthesis.
Hot deserts = Extremely dry climate. No vegetation usually occurs.
Savannah = Warmer climate, close to tropical rainforest but has dry season. Growing of trees is therefore limited by amount of water falling. One large transition zone from rainforest to desert
Temperate biomes
Mediterranean, evergreen, grassland
Cold biomes - higher latitudes
Tundra = competition for nutrients. Many bulbs - a way to survive as it grows underground. Short growing season above ground. Short succession stages mostly mosses and no trees can grow
Taiga = cool climate and little precipitation.
Podzolic soils.
Coniferous forests
Epiphytes
Plants that grow on another plant.
Example is pineapple. Often in rainforest. Cannot capture roots in the soil themselves.
Coral reefs biome
Covering small areas but accounting for over 1/4 of the oceans total species biodiversity.
Can help us reveal the past climatic history.
Estuaries
Transition zones where the freshwater of the river meets the salt water of the ocean (examples include: mud flats and mangrove forests)
Succession
The sequential change in species over time following a disturbance event.
Disturbance: forest fire or volcanic eruption
Example: Taiga - Final succession stage is coniferous trees as its too cold for further development of forest
Primary succession
Starts in an area that has a complete lack of life (perhaps because of a volcano erupting)
Lacks competition
Secondary succession
Takes place after less dramatic disturbances (forest fires for instance, deforestation or construction activities). Soil existed before and can therefore progress faster than soil in primary succession
Habitat corridors
Can help to deal with fragmentation in nature. To connect patches of an ecosystem. To help species migrate. Examples could be tunnels under big highways to join two habits together.
Island biogeography theory
Islands tend to be less biodiverse because of water or other features blocking access to mainland for species to migrate.
However niches develop for special species that become endemic (only existing at a certain spot)
Larger islands = greater richness in species than smaller islands as larger islands probably have more resources and different habits.
Ecosystem services
The direct and indirect contribution of ecosystems to human-well being
4 categorises of Ecosystem services
Provisioning, cultural, regulating and supporting
Regulating ecosystem services
Indirect services of ecosystems. The benefits of having a regulating water system, climate system and erosion system
Example: presence of trees allows the impact of heavy rainfall on the soil to be moderated by a barrier (leaves or branches) to allow a longer period for soil water replenishment.
Cultural ecosystem services
The non-material benefits. The aesthetic, knowledge, social and spiritual (ethical too).
Difficult to put a price on.
What we leave for the future (the lost biodiversity).
Supporting ecosystem services
Indirect services.
The soil formation, photosynthesis, water cycle
Provisioning
The direct supply from ecosystems. The products. The food, the fuel, fibre and pharmaceuticals.
What essential functions does soil perform?
Reservoir for water (aquafiers etc), medium for plant growth and food, filters the air and the water, recycles dead plants/animals, storing huge amounts of carbon
Climatic variables affecting plants - light
Leaves capture light via photons (green pigments -chlorophylls) which leads to carbon being absorbed and converted into glucose which is needed for future growth
Climatic variables affecting plants - water
Supply of water needed for growth. Drought can be dealt with by shedding the green leaves for instance.
The turgor needs water to keep leaves up
Climatic variables affecting plants - temperature
Reactions involved in photosynthesis require warmth. Best between 10 and 30 degrees.
Climatic variables affecting plants - carbon dioxide concentration
Increase in co2 leads to increase in photosynthesis.
Which environmental factors determine plant growth?
Sun radiation, soil moisture, climate but also human interference
Vegetational change
Noted differences in different vegetation land due to warmer temperatures. Vegetation is moving upwards - shift in northern tree line
Phenology
The study of the timing of natural phenomena related to the climate such as time of flowering and seed formation
Vegetation studies with pollen change
Analyse pollen to show a shift from shrubs to trees as a result of climate becoming warmer
Modelling plants response to climatic variables
- link individual species to biomes
(deciduous broadleaf forests for instance)
= PFT
To understand how much carbon dioxide is up taken by plants - more clouds are formed and less carbon released to space
Biogeography
global scale -
Why are some animal and plants placed on certain areas on earth?
Study of geographical distribution of animals, life, plants and vegetation.
covers adaption and change over time
Abiotic vs biotic
Abiotic - soil, water etc
Biotic - competition among organisms or diseases
Tolerance limit
a range of what a specie can tolerate in their natural environment
Limiting factors
Plants can only grow if the minimum limit is reached in the environment and there is a maximum limit of how much an organism can grow
Ecosystems and ecotype
Ecotope: all the plants and animals living within the ecosystem (biotic environment)
biotope: the physical (abiotic environment)
ecology: the study of ecosystems
Savannah ecosystem
Drier environment but if more drought would occur it would lead to less moisture in the soil, leading to loss in grass and less food for ungulates and they will migrate to find grass (grazing)
Niche
Specific habitat for a specific specie
Heath field stage of succession
Bushes
Unstable succession
Competition between species
Between and within habitats. They have to adapt to disturbance to survive.
Movements and migration
movement back and forth on regular basis most often in between summer and winter
Biomes
Zones that have certain characteristics that shape and form life and composition of plants and animals. Based on vegetation but related to soil and climate with large regional difference
vegetation
System of more or less spontaneously growing plants
Hotspot theory
In some areas you can find a larger biodiversity - different around the world. Some species might only live there and therefore essential to protect.
Terraced crop growing
Sustainable way to farm to avoid soil erosion with “steps” in slopes.
What are ecosystem services?
Different definitions. “A wide range of conditions and processes through which natural ecosystems and the species that are a part of them, help sustain and fulfill human life”
or
“Contributions of ecosystems structure and function in combination with other inputs to human well-being”
Food as a part of provisioning services
Animal: Dairy, eggs, meat
Plant: Seeds, fruits
Other: bacteria and seaweed
Feeding as part of provisioning services
Animal: fish, bone meal
Plant: Corn, soybeans, oat
Other: seaweed
Fiber as part of provisioning
Animal: Collagen, feather, fur, silk, wool
Plant: Cotton, Bamboo, Hemp, Jute
Other: Seaweed
Fuel as part of provisioning
Animal: Dung, fat, biomass
Plant: Biomass, Oil, fossil fuels
Other: Microalgae
Pharmaceuticals as part of provisioning
Animal: Gallstones, Venom, Urine, insulin
Plant: Expectorant, Diaphoretic, Febrifuge, Astringent
Other: Microalgae, seaweed, microorganisms
Others things part of provisioning
Animal: Shellac, Beeswax, Tallow
Plant: Resin, wax, dyes, soups
Other: biopesticides, seaweed, dendrology
Regulating + supporting services
Purification of water and air
Reducing drought and floods
detoxification of wastes (decomposition)
Pollination of crops (dispersal of seeds)
Cycling of nutrients
Maintaining biodiversity
Protects shore from erosion
Protects from harmful UV rays
Partial stabilisation of the climate
moderation of weather extremes and their impacts
What problems are ecosystem (+ services) facing?
Ecosystems are often undervalued (especially the regulating and supporting services) as we dont see them directly
Disruptions of the ecosystems are caused by humans are impossible to reverse on a human relevant time scale
So a continued lack of awareness will dramatically alter earths remaining natural ecosystems within a few decades
Provisioning services: fishing for food
2016 - 7.6 billion people
average 20 kg of fish per person
= 152 million tones of fish in a year
90% of worlds largest fish stocks are fully exploited or overexploited
Provisioning services: Medicine
Brazil earns millions of dollars a year on medicine found in the Amazon but now grown in greenhouses which could lead to lost gen variability
Regulating + supporting services: Atmosphere
Helps to alter the concentration of greenhouse gases in the atmosphere which leads to cooling.
A positive feedback loop of cooling (lower sea levels, more eroded land, fertile waters with phytoplankton that helps deal with carbon leading to more cooling)
Deforestation could dramatically reduce total precipitation
Regulating + supporting services: Floods/droughts
Water is dispersed to plants, aquifers and streams by soil
The plants help protect the soil from erosion
If we strip the forest and plants we get more mud and less ability for soil to absorb the water leading to more erosion, less nutrients to grow crops and disrupts water quality and can increase severity of flooding
Solution? Wetlands! Slowing down water flow and minimising pressure + allowing for deposition and less sediment to fill up water streams
Regulating + supporting services: Soil
Soils provide recycling of nutrients, provides plants with physical support, retains + deliver nutrients to plants, plays a role in decomposition of organic matter and regulates carbon/nitrogen/sulphur cycle
Hydroponic systems
A way to save space when dealing with soil as a provision for physical support. Very expensive method
Regulating + supporting services: Pollination
Flowering plants require animal pollination as over 100.000 animals acts as pollinators
They require complex ecosystems to stay alive
Diseases, decline in diversity and invasive species threatens pollinators
Regulating + supporting services: Pest control
Huge issue for agriculture. 99% of all potential pests are controlled naturally via ecosystems.
Can lead to decline in sperm count and lead to resistance for future use
