The effect of the high CO2 on leaf anatomy and other leaf features in three Atlant...
| Grant number: | 07/59708-1 |
| Support type: | Regular Research Grants |
| Duration: | May 01, 2008 - April 30, 2010 |
| Field of knowledge: | Biological Sciences - Botany |
| Principal Investigator: | Marcos Silveira Buckeridge |
| Grantee: | Marcos Silveira Buckeridge |
| Home Institution: | Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil |
Abstract
Alterations in temperature and in the pluvial regime related to the emission of gases that cause the greenhouse effect represent a new threat to global biodiversity. Legumes are one of the most important families in the domain of the Atlantic and tropical forests, both for the number of species and individually in the structure of Atlantic forest. Studying five species of legumes, our group observed that the pattern of physiological performance of each species is related to the position occupied by the plant in the process of ecological succession. This data indicates that the successional process could be influenced by the management of the water absorbed by each species. Since the end of the decade of the 1980s, studies have shown that plants respond to the increase in concentrations of CO2 in the atmosphere with a reduction in the number of stomata. Analyses of increase or decease in the number of stomata in a leaf are carried out by calculating the stomata index or density, and the results are taken by the literature as an indication that the plants have been responding to these alterations. This knowledge is widely disseminated throughout the scientific community, but to-date very little is known about the responses of the species of tropical ecosystems to growing increases in this gas. In the present proposal we will use an intraphyletic approach, which seeks to conduct studies in greater depth into the physiological (photosynthetic and morphological) and anatomical responses of the species of legumes of different successional groups: Sesbania virgata (pioneer), Schyzolobium parayba (initial secondary) and Hymenaea courbaril (late secondary) to climatic changes, through the study of the combined effects of raised CO2 and temperature. For this purpose, the plants will be cultivated in conditions and concentrations of CO2 and temperature expected in the second half of the XXI century. Measurements will be taken of the allocation and accumulation of biomass, of photosynthetic behavior, measurements of C/N relationship, analyses of structural and non-structural sugars and analyses of stomata index. With the results obtained it is intended to examine in greater depth and improve the precision of models of behavior of different species of legumes, so as to predict with greater precision the responses to climate changes occurring on the planet. (AU)