ENV234H1 Lecture Notes - Lecture 12: Chlorophyll, Phenology, Cladocera
Document Summary
Lecture 12 terrestrial biomes: what structures biological communities. Acidification of temperate soils: ph in 1880"s was much higher than it is now. Recall ph is a log scale: so a drop of 2 units is a large amount. But still more leaching at the surface. Recall if there are a lot of h+ ions, al can be pulled off and be toxic to plants/animals. So drop in ph = more al in solution. From 2 coloured maps: blue = calcareous, red = acidification, from 1980 to 2000 much less calcareous in grasslands. Variations between different types of grasslands (plot) Average decrease of 0. 6 ph in all grasslands (very large amount due to logarithmic scale) Red spruce: 1970 -1980s, large amounts of canopy mortality, mostly in high altitudes (cold temperatures, lack of calcium prevents them from being as frost resistant. Sugar maples: lack of calcium has also affected, liming sugar maple forest to raise ph of soil.
