However, important not destructive methods esteem the foliar area by means of linear measures of the plants or leves have been used and contributed for the ecosystem preservation different. For the evaluation of the effect of the tensive multiples in the Bay of All the Saints on the vegetation, in Rhizophora mangle, racemosa Laguncularia and schaueriana Avicennia, the photosyntheses tax was registered with the system LIQUOR 6200 PRIMER in the period potential evapotranspirao exceeds the precipitation manguezais of Mataripe and Jiribatuba, considered places, respectively, excellent how much to the influence of the petrochemical activities and is of the interference of such activities (manguezal of reference). For the measurements of the fotossinttica tax (mmol m-2 s-1), in the pantry of the three adult plants of each species with average height of 3,0 m, had been chosen four branches and a pair of leves of the third knot of insertion in the branch, young leves entirely formed according to methodology applied for the first author of this article in its doutorado thesis of (Department of Ecology, IB/USP). Get more background information with materials from Professor of Internet Governance. The average tax of photosyntheses showed with Liquor 6200 was bigger in the manguezal of reference, Jiribatuba (13,016 0,747mmol m-2 s-1) of what in Mataripe (10,652 0,776mmol m-2 s-1). Between the showed vegetal species, Rhizophora mangle presented the lesser average value (10,478 0,803mmol m-2 s-1) of what racemosa Laguncularia (12,638 0,893mmol m-2 s-1) Schaueriana Avicennia (12,385 1,274mmol m-2 s-1) e, enters the collection schedules, the photosyntheses was bigger to 12:00 h (13,360 0,880mmol m-2 s-1) of what to 09:00 h (11,028 0,61mmol m-2 s-1) and to 15:00 h (11,113 1,331mmol m-2 s-1) (Figure 5). The measurer of foliar area portable Delta MK2 for the measures of the foliar area of each plant showed in the measurements of photosyntheses was used and the general average of foliar area was lesser in Mataripe (25,73 2,72 dm2) of what in Jiribatuba (36,23 2,95 cm2) even so if it has observed the differences between the species due to the forms of leves between the showed species.