DSST Environmental Science cheat sheet

Integrated foundations: DSST Environmental Science

• Define the boundary, time period and units of a budget.

• Distinguish energy flow from material cycling.

• Relate exposure and effects without claiming one universal toxicity threshold.

• Compare management outcomes and life-cycle tradeoffs with evidence.

• Energy flows one way and is lost as heat; matter cycles

• 10% rule limits food chain length and top-predator abundance

• NPP = GPP − respiration; highest in rainforests, wetlands, estuaries

• Know nitrogen fixation, nitrification, denitrification; phosphorus has no atmospheric phase

• Removing a keystone species triggers trophic cascades

• Three levels: genetic, species, ecosystem diversity

• Richness = number of species; evenness = relative abundance

• Allopatric speciation requires geographic isolation; sympatric does not

• Ecosystem services: provisioning, regulating, supporting, cultural

• Island biogeography: larger, closer islands hold more species

• Exponential (J) vs. logistic (S) growth; logistic levels at carrying capacity K

• Density-dependent factors scale with crowding; density-independent do not

• Survivorship curves: Type I, II, III

• Rule of 70: doubling time ≈ 70 / growth rate %

• Age-structure pyramids predict momentum and future growth

• Plate boundaries: divergent (ridges), convergent (trenches/volcanoes), transform (faults)

• Rock cycle links igneous, sedimentary, metamorphic rocks

• Soil horizons O-A-E-B-C-R; texture drives water and nutrient behavior

• Ozone sits in the stratosphere; weather occurs in the troposphere

• Coriolis effect and unequal heating drive winds and currents