Flashcards Terrestrial Ecosystem Ecology

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• Why is the ecosystem concept so important for managing Earth's resources? Since it addresses the interactions which link the biotic system with the physical system, and people are a part and depend on these.
• What is that target of research for ecosystem ecology? Links between organisms and their physical environment.
• Why is it important to study the flow of energy and materials in an ecosystem? Because it provides a framework for understanding the diversity of form and functioning of Earth's physical and biological processes.
• Why do tropical forests have large trees but only a thin layer of dead leaves compared to tundras? Since tropical forests have less fertile soil than tundras.
• What's the aim of ecosystem analyses? Understanding the factors that regulate the poosl and fluxes of materials and energy through ecosystems.
• Give examples of fluxes Absorption of minerals by plants, fall of autumn leaves, decomposition of dead organic matter
• When is an ecosystem at steady-state? When the balance between inputs and outputs to the system shows no trend with time.
• What is succession? The directional change in ecosystem structure and functioning that follows disturbance.
• Which are the essential abiotic components of terrestrial ecosystems? Water, the atmosphere and soil
• What are the major components in a ecosystem model? Plants, animals and decomposers.
• What are the state factors that govern ecosystem structure and functioning? Climate, parent material, topography, potential biota and time.
• Which factor determines most strongly the ecosystem processes and structure, on broad geographic scales? Climate
• How does stabilizing feedbacks work? By one component having opposite effect on another.
• How does amplifying feedbacks work? By two components having positive effect on one another.
• Name three novel chemicals introduced by humans. CFCs, DDT and PCBs.
• What is resilience? The capacity of social-ecological systems ot maintain similar structures, functionings and ffed-backs despite disturbance.
• How is that biodiveristy can confer resilience? Since a larger number of species is likely to sustain ecosystem processes over a broader range of conditions.
• What are the three main ecosystem services that society benefits from? Provisioning, regulating and cultural services
• Give examples of provisioning services? Ecosystem goods eg. food, fiber and water.
• Give examples of regulating services? Regulaton of climate, water quantity and quality, disease, wild fire spread and pollination
• Give examples of cultural services? Recreational, aesthetic and spiritual benefits.
• Which two factors govern the rates of many biological & chemical reactions that control critical ecosystem processes? Temperature & water availability
• What radiatively active gases absorb 90 % of outgoing longwave radiation? Water vapour, carbon dioxide, methane, nitrogen oxides & industrial products eg CFCs.
• What is an aerosol? Small solid or liquid particles suspended in air.
• What determines the reflectvity (albedo)? Aerosols together with clouds, gases and snow/ice.
• How does vegetation influence climate? By its effects on the surface energy budget.
• How does overgrazing contribute to cooling and reduced capacity for a area to recover? Since it increases albedo, reduces energy absorption and the transfer of energy to the atmosphere.
• Why does deserts have such high surface temperatures? Because of their dry smooth area and the limited suppy of moisture.
• What has primarily driven millenial-scale climatic change? Changes in the distribution of solar input & changes in atmospheric composition.
• What variations in Earth's orbit influence the amount of solar radiation received a different places & periods? Eccentricity, tilt and precession.
• What is the definition of eccentricity? The degree of ellipticity of Earth's orbit around the sun.
• What the definition of tilt? The angle between Earth's axis of rotation relative to the plane of its orbit around the sun.
• What is the definition of precession? A wobbling in Earth's axis of rotation with respect to stars, determining when different locations are closest to the sun.
• Name a proof of anthropogenic climate change? Earth's climate btween 1950-2000 have been warmer than any 50-year interval during the last 500 years or more.
• How does the atmosphere influence radiation? It transmits 50% of incoming shortwave but absorbs 90% of outgoing longwave.
• How does convection work? Cool material sinks, sinking material heats up, hot material rises, energy released to cooler region etc.
• Explain the rock cycle. Soil/rock-->sediments-->sedimentary rocks-->metemorphic rocks-->magma-->igneous rocks-->soil/rock
• When is the availbility of phosphorus for plants highest in geologic substrates? Early in the newly exposed substrate.
• Give the characteristics of the layers of soil above the bedrock. Top: Organic(decomposed)-->Mineral+humus-->Leaching-->Metals(accumulation)-->Parent material.
• What factors determine the soil profile? Decomposers, humidity and temperature.
• What do we know of soil pH globally? Generally low; acidic.
• What human activities increases soil erosion? Cultivation, redirection of waterflow, deforestation.
• What human activities decreases soil erosion? Construction of big urban constructions, growing of crops in big terraces.
• Explain how river discharge and elevational gradient influence patterns of river channel morphology. (Erosional zone); Predominance of erosion in streams with steep gradients/high discharge. (Depositional zone); predominance of deposition in streams with shallow gradients/low discharge.
• What factors does soil chemistry depend on? Mineral components, water, pH and surface area.

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