Option+G

Page 330 1.19 580kJm –2 yr –1 //(units required)// 1 2. autotrophs lose 55 % of their gross products to heat compared with the heterotrophs which lose 96.3 % (96) of their food energy / 41 % more of hetertrophs; 1 //Numerical comparison required// 3. animals use a lot of energy to move maintenance of body temperature / other valid reasons 1 Page 331 succession question 1.  a)  increasing   b)  stable/decreasing 2. a) increasing because of greater leaf area index b) ambiguous because decrease in number of species but decrease in dominance by single species (normally as succession proceeds diversity increases because greater productivity means longer food chains and more niches); c) improved soil structure because more detritus favouring soil-based food chains increasing aeration/ detritus prevents run-off with accompanying erosion of top-soil; d) more detritus decreases compaction by rainfall/less run-off/ more infiltration/ shade affects micro-climate decreasing evaporation/ greater storage of water in tissues/ increases in net transpiration; Page 338 the data is variable/correlation may not be direct; population did not have sufficient time to recover from near extinction in those years; cumulative effects of cold temperatures and overfishing; One point for discussion might be that the fishing industry might have noted the correlation between warm water events (El Nino) and higher populations. This might have lost its power as a predictive tool when the population fell below a critical level.
 * 1) 1949 and 1955
 * 2) 1949 and 1934
 * 3) the higher the temperature, the higher the year class;
 * 1) preceded by relatively cold years in 1954 and 1953;