ENVR 3400 - ecology and ecosystems as foundational for health

ecology

“oikos” ; integrates info at multiple scales to help understand systems holistically; moral, ethical, and legal responsibilities must be considered

ecosystem

complex systems of organisms, environment, and interactions

scales of ecology

from…

molecules, cells, tissues/organs, organism, populations, communities, ecosystems, planet

bioaccumulation

persistent pollutants can bioaccumulate and biomagnify as they move up food webs

population ecology

study of dynamics of species’ populations and interactions, that change over time and space

• no constraints = populations grow exponentially (human AND non-human)

what factors constrain growth at a population’s carrying capacity?

competition, predation, parasitism, resource limits

carrying capacity

max population size of a species that the environment can sustainably support without degrading the habitat

conservation biology

seeks to halt extinction

• population decline = deaths > births = can lead to extinction if exacerbated

how do predators and parasites tend to regulate population growth

• make host less fit to reproduce rapidly

• number and viability of predators and parasites are regulated reciprocally

  • e.g. less predators = more prey because they are not being consumed a lot

community

assemblage of dependent species

• community ecologists: studies succession (temporal change), symbiosis, etc.

unique feature of community

most things living there have to grow TOGETHER (simultaneously)

what do ecosystem ecologists study

larger scales of energy, water, nutrient cycling (e.g. food webs)

many essential ecosystem functions (e.g. nutrient cycling) are performed by…

microbes and invertebrates

• more species = ecological richness = more ecosystem functions performed

microbial symbiosis on biota

relationship between microorganisms and larger living things (biota)

interactions in microbial symbiosis

mutualistic: both benefit

commensalistic: one benefits, one unaffected

parasitic: one benefits, one affected

how does wastewater treatment utilize microbes

microbes, alongside oxygen naturally feed and break down pollutants, converting them into water, CO2, and harmless byproducts

millennium ecosystem assessment

how ecosystem changes affect human wellbeing; it can support human wellbeing in 4 ways

4 ways ecosystem functions can support human health and wellbeing (MEA)

provisioning, regulating, cultural, supporting

examples of provisioning (MEA)

water, food, fiber, fuel, genes, etc.

examples of regulation (MEA)

climate, air and water quality, pollination, erosion, disease transmission

examples of cultural (MEA)

spiritual, religious, aesthetic, knowledge, recreation, ecotourism, etc.

examples of supporting (MEA)

photosynthesis, primary production, water cycling, nutrient cycling

what are some indirect drivers of change

demographic

economic (globalization, trade, market, etc.)

sociopolitical (governance)

science and tech

cultural and religious (e.g. beliefs, consumption choices)

what are some direct drivers of change

changes in local land use

species introduction or removal

tech adaptation and use

external inputs (e.g. fertilizer, pest control)

harvest and resource consumption

climate change

natural, physical, and biological drivers