IB ESS HL 2.4 Climate and Biomes Questions

temperatures over $24^{\circ} \mathrm{C}$;
rainfall between 1000 and $3000 \mathrm{~mm}($ eg $1501-2000 \mathrm{~mm})$ / rainfall below 2000/3000 mm;

$27^{\circ} \mathrm{C} /$ from -4 to $(+) 23^{\circ} \mathrm{C}$;

Tropical rainforest has:
a. High species/habitat/niche diversity / high biodiversity / hotspots / many endemic species;
b. High primary productivity / high photosynthetic rate / serve as major carbon sinks / produce a lot of oxygen;
c. High nutrient turnover / high decomposition rate;
d. High rates of insolation;
e. High mean temperatures;
f. Abundant precipitation / high humidity;
g. Nutrient-poor/acidic soils;
h. Thin topsoil layer / rich in organic matter / very deep overall / red colored (rich in iron);
i. Dominated by tall straight trees;
j. Complex/highly branched food webs;
k. Stratified ecosystem / tree buttresses in ground level, dense broad-leaved canopy, emergent trees;
l. Found around the Equator / between Tropics of Cancer & Capricorn;
m. Low/no seasonality/annual fluctuation in climate (precipitation and temperature);

a. High amounts of sunlight energy are absorbed by the oceans at the equator/tropics;
b. The ocean has an interconnected current, or circulation;
c. Ocean currents distribute that heat/move warm water/humidity/precipitation from the equator/tropics to the poles;
d. Ocean currents transport cold water from the poles back to the equator/tropics;
e. Currents are driven by wind/tides/Earth's rotation/solar energy/water density differences;
f. Regions at higher latitudes therefore have warmer climates than they would be without ocean circulation;
g. Example of warm current from equator toward poles such as Angola or Gulf stream / example of a cold current from poles to equator such as Humbolt;
h. Example of the prediction that the loss of the Greenland ice sheet affecting the Gulf stream resulting in a colder Europe;

The sub-headings below are for guidance only. Credit should be given for the Marking points whether the student identifies them under these titles or not.

Global Warming element:
climate change/biomes shift;
Distribution:
biomes move towards higher latitudes / altitudes;
Credit a detailed example
Diversity:
if the shift is too rapid some species will not be able to survive, decreasing diversity;
if the species are on islands or mountains they may run out of space to migrate to;
keystone species/critical to ecosystem, whole ecosystems may be lost/damaged;
changes to the precipitation/temperature/humidity may make an area more or less conducive to the existing ecosystems;
For example, desert areas may receive more rainfall so allowing a more diverse ecosystem;
For example, Sub-Saharan areas receive less rainfall leading to desertification / (southward) expansion of Sahara desert increased fires in tropical rain forests (due to higher temperatures or increased aridity) would lead to loss of species / reduce niches;
altered rainfall patterns might reduce habitat diversity;

Global Warming element:
melting ice caps/permafrost;
Distribution:
exposed areas after melting in high latitudes and/or altitudes;
Diversity:
the newly exposed areas might support new tundra ecosystems, potentially increasing diversity;
if ecosystems space in the tundra is reduced then diversity decreases;
flooding of coastal area ecosystems will reduce ecosystem diversity;
positive feedback loops might occur with the release of methane/clathrates accelerating further global warming/ climate change, stressing ecosystems even more;

Global Warming element:

Changes to the oceans/aquatic areas (higher water temperatures/change in El Nino frequency and intensity);

Distribution:
areas closer to the surface/shallow depth ecosystems are more exposed to the changes;
Diversity:
higher temperatures are likely to bleach/destroy some coral ecosystems; ...and accelerate ocean acidification, damaging plankton/base of marine ecosystems;
ocean circulation may alter allowing some areas to become more diverse;
a possible change of deep sea currents may benefit some areas that would receive more nutrients, thus increase species diversity;
a possible northward movement of Gulf Stream may benefit Iceland and Greenland (ameliorate temperature);

Global Warming element: thermal expansion of sea/ sea level rise;
Distribution of biomes:
increased erosion of coast/ alteration of continental shelf landscape may alter the extent of littoral/shallow coastal zone;
flooding of coastal ecosystem may destroy them, e.g., mangroves; ...but at the same time create new littoral/tidal ecosystems;
Diversity:
reduce intertidal habitat diversity as some species won't tolerate the shift of tide lines (low \& high);
creation of new tidal fronts may bring more nutrients thus increase aquatic species diversity;

Marking guidance:

a. Zermatt is wettest in the summer months of May, June, July and August / peak precipitation in Zermatt is in May / total precipitation per year in Zermatt is $590 \mathrm{~mm} /$ maximum precipitation in Zermatt is 70 mm ;
b. Montana is wet all year / peak precipitation in Montana is in December / total precipitation per year in Montana is $830 \mathrm{~mm} /$ maximum precipitation in Montana is about 99 mm ;
c. Montana is wetter than/has more precipitation (than Zermatt) / Zermatt has less precipitation (than Montana);
d. Temperatures range from approximately $-1 /-2^{\circ} \mathrm{C}$ to $16 / 17^{\circ} \mathrm{C}$ in Montana / highest mean monthly temperature is $16^{\circ} \mathrm{C}$ in Montana;
e. Temperatures range from approximately $-3 /-4^{\circ} \mathrm{C}$ to $14^{\circ} \mathrm{C}$ in Zermatt / highest mean monthly temperature is $14^{\circ} \mathrm{C}$ in Zermatt;
f. Temperatures are colder in Zermatt (than in Montana) / Montana is warmer (than Zermatt);