<Tr> <Td> Extreme desert and ice </Td> <Td> 24.0 </Td> <Td> </Td> <Td> 0.07 </Td> <Td> 0.02 </Td> <Td> 0.5 </Td> </Tr> <Tr> <Td> Cultivated land </Td> <Td> 14.0 </Td> <Td> 650 </Td> <Td> 9.1 </Td> <Td> 1.0 </Td> <Td> 14 </Td> </Tr> <Tr> <Td> Swamp and wetland </Td> <Td> 2.0 </Td> <Td> 2,000 </Td> <Td> 4.0 </Td> <Td> 12.3 </Td> <Td> 30 </Td> </Tr> <Tr> <Td> Lakes and streams </Td> <Td> 2.0 </Td> <Td> 250 </Td> <Td> 0.5 </Td> <Td> 0.02 </Td> <Td> 0.05 </Td> </Tr>

The lowest rates of primary production take place