Feeding Humanity Flashcards
(33 cards)
pop growth
has started to decline, most prominent in Asia and Africa, decreases are mostly in developed nations
population pyramid
describes the age distribution of a pop across diff years
stages of the population pyramid
- high birth and death rate, short life expectancy
- high birth rate, declining death rate, slightly longer expectancy, higher proportion of middle-aged ppl
- declining birth rate, low death rate, long expectancy, increasing proportion of older ppl
- low birth and death rate, longer expectant, higher dependency ratio
4 significant periods of societal change that altered relationship with the env and led to rapid pop growth
- Paleolithic Period: humans learned to control fire, developed stone tools, promoted longer lifespans, capacity of tribes to hold ppl extended
- Agricultural Revolution: after the last ice age, groups of ppl congregated around water sources, formed communities that eventually became cities, transitioned from nomadic hunter-gatherer societies into settled agricultural communities, led to intensification of relationships between ppl and land
- Industrial Revolution: rural-to-urban transition, heavy reliance on fossil fuels and natural resource extraction, fueled more ag growth, better machinery, higher production, and more food to support a growing pop
- Medical-technological Revolution: increases in global communications, pharmaceuticals, manufacturing, sanitation, and ag
soil
living system, vital nexus in biogeochemical cycling of N, P, and C, involved in physical, chemical, and biological processes (like decomposition and respiration), has many organisms that interact, facilitates nutrient release, storage, and uptake
layers/horizons of the soil
- Organic - top layer with the most organic matter
- Surface
- Subsoil
- Substratum
- Bedrock - the lowest layer, mostly inorganic matter
pedogenesis
slow and complex process of soil formation, begins with sediments and are often layered, can be easily interrupted, reversed, or nullified by changing inputs or catastrophes, soil is composed of mineral matter, organic matter, soil air, and soil water, developed by weathered parent material, organisms, optimal temp and moisture regimes, low rates of erosion or deposition
soil classification
associated with bioclimatic conditions in which they form, key classification properties include colour, texture, pH, and structure
desert soils
thin organic layers, top layer tends to be rocky
grassland soils
thicker organic layers, contains salt layers
tropical rainforest soils
low organic matter, prone to decay
deciduous forest soils
thick layers, podzols, slightly acidic, humus layer, porous
coniferous forest soils
acidic, low in minerals, nutrients, organic matter, and invertebrates, podzols, humus
agriculture
domestification of flora and fauna, intensified thru the expansion of uses of soil and surfaces
traditional agriculture
largely biologically-powered (human and animal muscle power), subsistence ag (done by families and communities to feed themselves), labour intensive, low input costs
industrial agriculture
focuses on market commodities for profit, mechanized, commercialized, largely based on annual plants grown in monocultures (lack of biodiversity degrades the soil which requires fertilizers), high-cost inputs to boost yields
green revolutions
involve a package of inputs and techniques (requires high energy and results in significant GHG emissions, large increases in synthetic fertilizers, and biocide inputs), allows the development of higher-yielding crop varieties thru hybridization (leads to significant yields but loss of biodiversity of crops), led to the creation of genetically modified organisms (GMOs, which may be unsafe and damage the env), involves irrigation (ag is the largest consumptive water user, requires large-scale water diversions)
undernourishment
consuming little calories, mainly found in developing countries
malnutrition
inadequate (amount and types of) calories, vitamins, and minerals
overnutrition
consuming too many cals a day, mainly found in developed countries
food systems
involves privatizing, processing, promoting, profiting, vertical integration, patenting, and monopolization; results in the loss of family farms, reduction of local community self-reliance, and an increase in contribution of food to ecological footprints
livestock revolution
global shift towards intensive livestock operations (like feedlots and factory farms), involves high energy use and other inputs like water, grain feed, antibiotics, and fossil fuels, shift has driven growth in meat production and consumption, ethical concerns surrounding manure management, pollution, impacts of production inputs, and antibiotics/animal abuse
impacts of overgrazing
- compacts soil and damages structure
- decreases water infiltration and aeration
- removes native grass
- exposes bare topsoil
- wind and water erosion
- invasive species can outcompete natives in the altered env
- decreases grass growth and survival
impacts of agriculture on the soil
- compaction
- wind and water erosion
- desertification (transition from a productive landscape into a desert-like landscape)
- salinization
- waterlogging
- chemical contamination
- organic matter loss
- nutrient depletion
- reduced soil biodiversity
