Land vs. lake productivity. Lake thermal structure is determined by several factors. Lake surface area relative to upstream catchment size and lake perimeter‐to‐surface‐area ratio were also important, with smaller upstream catchments yielding higher production, and high shoreline complexity correlated with lower productivity as measured by limnetic PR. Lakes receive the vast majority of their heat at the surface from solar heating. Jeppe Kolding, Paul A.M. van Zwieten, Relative lake level fluctuations and their influence on productivity and resilience in tropical lakes and reservoirs, Fisheries Research, 10.1016/j.fishres.2011.11.008, 115-116, (99-109), (2012). The index also has a strong log-linear relationship with the fish productivity. Because lake productivity was measured solely by water column chlorophyll a in this study, this weak causality is expected. The thermal structure of lakes helps determine productivity and nutrient cycling. 163–186 q 2001 by the ecological society of america trophic cascades, nutrients, and lake productivity: whole-lake experiments stephen r. carpenter,1,6 jonathan j. cole,2 james r. hodgson,3 james f. k itchell,1 michael l. pace,2 darren bade,1 kathryn l. cottingham,4 timothy e. essington,1 jeffrey n. houser,1 and daniel e. schindler5 Is it good or bad when, e.g., land gets flooded to create a reservoir? 163 ecological monographs, 71(2), 2001, pp. But as the annual relative yield from the highly diverse flood-regulation, then both external and internal impacts of and variable African lakes practically is constant around three ton changed or regulated water level dynamics on the aquatic biology per fisher per year (Fig. A broader definition of lake productivity, that is, incorporating factors operating outside of water column (e.g., riparian meadows and mudflats), would result in a closer relationship and higher model performance. 7.12. Fish production in these lakes is generally high, e.g. Mean summertime plankton respiration (R) and photosynthesis (P) in surface waters of lakes as a function of chlorophyll concentration, an index of overall lake productivity (del Georgio & Peters, 1994). Fig. It should be noted that in the more ecologically mature Lakes Malawi and Victoria, fish productivity is less than 50 kg ha-1. relative to the atmosphere. 3.2 Lakes … ... (the relative depth of t he lake has a . About 280 000 cu.km of water exists on earth in the form of lakes. Relative lake level fluctuations and their influence on productivity and resilience in tropical lakes and reservoirs. Do lakes have lower or higher primary and secondary productivity per unit area compared with land? PDF | Lakes occupy about 1.8 % of the earth’s surface. ... continuum of productivity. Lake Kyoga (389 kg ha-1, Lake George 156 kg ha-1 and Lake Mweru Wantipa 100 kg ha-1). 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