Estudos multidisciplinares em arranjos agroflorestais biodiversos na Região Sudoeste de Mato Grosso do Sul

Abstract

The biodiverse agroforestry systems (AFSs) have great potential for food production, income generating and restoration of degraded areas, depending on the types of arrangements and composition of plant species present in these agroecosystems. In this context, It has been developed a study with the objective of generating information to serve as a technical reference to guide the implementation and conduct of new biodiverse agroforestry systems in the Southwest region of Mato Grosso do Sul. The study was conducted during the period from March to August 2015, in the municipality of Bonito, involving five biodiverse AFSs, aged between ten and fifteen years, formed by different arrangements and densities of arboreal and shrubby species. The results obtained led to three chapters of this dissertation. The first chapter deals with the "floristic composition of biodiverse agroforestry systems as an alternative for the recovery of degraded areas." To this end, it was evaluated the floristic composition of five AFSs, and the floristic similarity of these systems was compared with three reference areas with native vegetation, located in the study area, which were studied by other authors. In each agroforestry system there have been marked 50 plots of 10 x 10 m, distributed at random, and in each plot all individuals of floristic species taller than 1.50 m were sampled. It was found the presence of 1496 individuals belonging to 139 species and these to 46 botanical families, highlighting in AFSs 4 and 3 the floristic composition with greater number of individuals and botanical families, and besides a greater abundance of native arboreal species, highlighting the zoochorous as to the dispersion syndrome. These AFSs also have more species among the successional classes: primary, early secondary and late secondary. These systems show high similarity to each other when compared with the native vegetation areas 1 and 3, and the dissimilarity in relation to other areas. Thus, AFs S 4 and 3 stand out because they have floristic composition that contribute to environmental restoration, highlighting as an important alternative for the recovery of degraded areas. As to the second chapter it is about the "Potential for multiple use of arboreal and shrubby species in biodiverse agroforestry systemsand carbon stock estimates in the aerial part of plants using different allometric equations in the calculations." All arboreal and shrubby individuals with over 1.50 m height were measured the circumference at breast height as well as plant height to estimate the carbon stock. To calculate the carbon stock different allometric equations were used. The shrubby and arboreal species present in AFSs studied were classified and identified in ten potential forms of uses, using literature searches for it. The AFSs 4 and 3 stood out as the forms of uses, such as medical, food and wood, attractiveness to fauna, ornamental, apiculture and handicrafts. From the use of allometric equations, it was found average carbon storage of 58, 626 t C ha-1 in the five biodiverse AFSs evaluated, and the AFSs 4 and 3 showed higher average of accumulated carbon in the aerial part of plants. Using the allometric equations 2, 5, 6 and 7, it was reached similar results as to the stock of carbon in the aerial part of the plants in AFSs with similar levels of adequacy. In chapter 3 we discuss about the economic valuation of some environmental services provided by AFS, identified according to the perception of farmers. The study was conducted from interviews with farmers responsible for systems, using a semistructured script with open and closed questions, the results were evaluated and analyzed according to the Likert scale of 0 to 10, based on the average. Another evaluation carried out, was the average level of importance, including sustainability indicators, assigned from consultations to nine experts from 14 different regions of Brazil, getting the information by completing a questionnaire. The weighting factor of intangible variables was calculated the average of the degree of importance of each environmental service and indicators listed by the experts through a script. It was used an adaptation of the environmental services valuation method as simplified alternative to economic quantification, by Reference Estimated Value for Environmental Benefits (REVB), from quantified variables, such as the stock of carbon in aerial part of shrubby and arboreal species of AFSs. As for the intangible variables it was evaluated the provision of services, regulating services, cultural services and support services and staff. The results show that the five AFsS would be able to receive a total amount of R $ 4,157.70 year-1 and on average R $ 841.54 year-1by fixing service and carbon storage, highlighting the AFS 4, which would be able to receive R$ 1674.46 year-1 by fixing service and carbon storage. The sum of intangible variables by quantifiable variables of the five AFSs generated average REVB equal to R$ 280,298.37 year-1, which corresponds to R$ 23,358.19 month-1. The greatest value of REVB was assigned to AFS 4 with R$ 669,784.00. These values can be understood as amounts to be paid to farmers to encourage them to keep biodiverse AFSs, providing environmental services to society. The results of studies of floristic composition, multiple use potential of the shrubby and arboreal species, the estimate of carbon stock and economic valuation of environmental services provided by biodiverse AFSs , show that these systems are strategic alternatives for recovery of degraded areas.