ANALYSIS OF GROWTH AND GAS EXCHANGE OF PLANTS Lonchocarpus sericeus (Poir.) D.C. IN FLOODING FOR THE RECOVERY OF THE RIPARIAN FORESTS

Abstract

http://dx.doi.org/10.5902/1980509812349In order to select species for using in the restoration of riparian forests on the banks of the Sao FranciscoRiver, in the state of Sergipe, an experiment was conducted to evaluate the growth and gas exchange ofplants Lonchocarpus sericeus (Poir.) D.C., subject to flooding conditions in the nursery. The experimentwas conducted at Forest Nursery, Department of Forest Sciences, Federal University of Sergipe (UFS),the municipality of São Cristóvão, (11 º 01 'S latitude and 37 º 12' longitude W, altitude 20 m) , stateof Sergipe, Brazil, from October 2006 to January 2007 under ambient conditions. We used a completelyrandomized design (CRD), factorial (2x7), two treatments (control - T0, plants at field capacity and flooded- T1) and days after flooding (0, 15, 30, 45, 60, 75 and 90 days). To simulate the condition of flooding,the plants were placed in plastic pots of black color with a volume of 5 L and more substrate. Followingthese pots were attached to pots with a volume of 10 L, which was added water until it reaches a waterdepth of 5 cm above the top of the plants. The control plants kept in pots with a volume of 5 L substratemaintained at field capacity. In non-destructive variables were used four replicates per treatment evaluatedevery fifteen days, where each replicate consists of six plants, totaling 24. Destructive variables used were4 replicates per treatment, determined biweekly from 15 days after flooding, where each replicate consistsof a plant totaling 24 plants. Therefore, 48 plants were used per treatment. The non-destructive variableswere height, diameter and number of leaves. While the destructive variables analyzed were dry weight ofroots, dry weight of shoots and dry weight of root / shoot ratio. In addition, we carried out analysis of gasexchange on a monthly basis and evaluated twelve plants per treatment, with two sampling leaves, fullyexpanded, per plant. The biometric variables were subjected to analysis of variance and subsequently theaverage test (Tukey p <0.05), while the values of gas exchange were taken from the standard deviationsof the mean. Thus, we observe that the flooding caused a reduction in height and dry mass of root / shootratio, from 30 days after treatment application. In addition, flooded plants showed morphological changessuch as hypertrophy of adventitious roots and lenticels, characteristics of species tolerant to flooding. Thenet photosynthetic rate has been reduced by 48.20% compared to control after 60 days. However, despitereductions in growth variables and gas exchange species Lonchocarpus sericeus showed promise in therecovery of riparian vegetation, due to its morphological characteristics of species tolerant to flooding.

Keywords

• Raízes adventícias
• Lenticelas hipertrofiadas
• Taxa fotossintética líquida