values per unit area in the Sabine Basin. In contrast to 

 the total agricultural value, the crop value per hectare 

 of cropland in 1974 varied much less [from about 

 $ :50/ha ($101 /a) in Sabine Basin to $445/ha ($ 1 80/a) 

 in Vemiilion Basin] . 



Since the early 1900s, the total area of cropland 

 on the Louisiana coast has been declining slowly (fig. 

 3-5), although the production per hectare for rice has 

 increased in a spectacular manner (Fielder and Guy 

 1975). In the Chenicr Plain, agricultural habitat has 

 increased 4% since 1952 (table 3.10), This small 

 increase generally reflects a substantial (9 to 45%) 

 increase in the eastern part of the Chenier Plain with 

 a net loss in Sabine and East Bay basins. 



Agricultural Activities that Affect the Environ- 

 ment. Loss of natural habitats to agriculture : Agri- 

 cultural activities take place in areas that were for- 

 merly wetland, ridge, or upland forest. Over 80% 



(7,285 ha) (1,800 a) of the increased agricultural area 

 since 1952 has resulted from draining natural and im- 

 pounded wetlands. Another 1.500 ha (3,707 a) have 

 been "reclaimed" from natural ridges and forested 

 land. As figure 3-5 shows, most of the land currently 

 in agriculture was being fanned many years before 

 1952. These old sites developed first on the fertile 

 prairies of the Chenier Plain and later on cleared 

 upland forests of the region. The normal sequence is 

 to use high, well-drained grasslands first, then to clear 

 upland forests, and finally to drain wetlands. At the 

 same time, urban expansion takes over agricultural 

 land, as shown for the Sabine Basin in table 3.11. 

 Between 1952 and 1974 there was no reversal of this 

 process in the Chenier Plain. That is, no agricultural 

 land reverted to natural wetlands or uplands, although 

 in the Sabine Basin, 204 ha (504 a) of pasture were 

 converted to open water habitat. , 



Table 3.10. Areal changes in agriculture habitats from 1952 through 1974. 



^Increase (+) or decrease (-) from 1952 area. 

 ''For East Bay from 1954 to 1974. 



Table 3.11. Hectares of natural habitat converted to agriculture, and agricultural habitat converted to 

 urban use in the Chenier Plain from 1952 to 1974. 



T"he totals do not agree with the total habitat changes in table 3.10 because some 

 minor conversions are not shown. 



Broken line indicates that habitat does not exist in the basin. 



35 



