Chapter 1: Form and process in
world food and ecosystems
Goal: Explain how biotic, abiotic and anthropogenic processes influence patterns in
ecosystems and food production systems in the past, present and future.
95% of mammal biomass is livestock.
70% of freshwater use for agriculture.
The shift is recent (big difference between 1900 and now), influences both forests and
grasslands, around 50% of habitable land is now used for agriculture, 77% of this is for
grazing or production of animal feed.
Dietary land use vs beef consumption it takes around 100 times as much land to produce a
kg of beef vs plant based.
Socioeconomic trends and earth system trends have a relation. Higher world population leads
to more CO2 emissions.
Keynotes: Turbulent epoch, humans are causing the world to change fast. Food production is
a large reason for that. This has consequences on biotic life and environmental quality.
Decisions in the world food and ecosystem management need to balance needs and
consequences.
Complex decisions require suitable description of the form/process.
Challenge of description
Finding an adequate level of complexity to analytically approach the problem.
Example: impact of urbanization on cropland and natural land?
Urbanization will drive changes in African food system and biodiversity through dietary
shifts rather than through urban expansion.
The focus in geography has shifted to processes and contexts/networks.
Environment has dimensions characterized by their descriptions (form) and mechanisms by
which it changes (process).
Biophysical dimensions of the environment:
- Atmosphere/climate
,Solar irradiation is the source surplus at equator and deficit at poles heat transfers in the
form of atmospheric and oceanic motion.
Influence of the earth’s rotation (Coriolis effect) and physical and chemical processes.
Koppen climate classification:
Level 1: 5 climate groups (tropical, dry, temperate, continental, polar).
Level 2 is the precipitation, and the third level is based on temperature.
Soil - Geology/Hydrology/Morphology
Results of lithology (interactions between parent material), climate, topography and
organisms.
Quantities like texture, water holding, CEC, acidity, organic carbon content.
Qualities like structure and colour. Most commonly classified using the WRB.
Human – Materials/Energy/Food
Key processes: GHG emissions, pollution, fertilization, eutrophication, irrigation, tillage.
Key concepts: CO2 ppm, carbon footprint, PM2.5, BC.
The processes within a sphere can be described at levels ranging from physical mechanisms
(convection) to abstractions (land conversion).
Simplification is needed and is based on the goal of the analysis, the scale and the available
datasets.
Biomes
Global scale zones with characteristic life forms. Larger level of abstraction, describe the
interface between climate-living communities.
Tropical rainforests: high and constant mean annual temperature and consistent high
precipitation, evergreen leaf.
Temperature forests: Moist but temperate, seasonality in vegetation.
Desert: Extreme temperatures and very low precipitation, competition for water and low and
open vegetation).
Tundra: Low temperatures, summer precipitation, low plants/mosses.
Taiga: boreal forests, only few months with T above 10 degrees.
Grassland: mean annual precipitation lower than 500mm, no trees.
Savanna: Open grassland with sparse trees, dry season.
, Biomes of the world:
Biomes incorporate now a lot of processes like human impact and removal of biomes
influences climate. Not just where vegetation forms occur.
Classification comes down to a trade-off: minimize homogeneity within a unit while
maximizing the heterogeneity between units of different classes. Simplify without losing
essential nuance.
Chapter 2 (&4) Biodiversity and
ecosystems.
Plants adapt to their biome. Leaf morphology, root investments, leaves (evergreen, all
year, or deciduous), nutrient availability, soil development, photosynthesis and growth
rates, growth form vegetation (trees, shrubs or grasses).
Forest canopy height.
Depends on moisture and temperature. Trees in one biome and shrubs and grasses in another.
Tropical biomes like rainforests are characterized by tall and dense canopies, well over 30m
sometimes.
High trees in the tropics and low trees in the Netherlands. This is because in the tropics there
are more hours of sunlight, no seasons, and higher temperature.
Temperate regions experience distinct seasons with variations in temperature and
precipitation.
Different leaf traits.
Optimize light capture. Minimize drought stress. Stomata must open from time to time for
photosynthesis.
Large thin leaves low light, high moisture. Suited for environments where light
availability is limited, like in dense forests. The large surface maximizes light capture, the
thin leaves facilitate gas exchange.
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