Functional Gradient of Atlantic Forest - Brazil

This research site develops long-term ecological studies in experimental units located in Protected Areas along the altitudinal gradient of Atlantic Forest types: Low Altitude Ombrophilous Dense Forest (5 to 50 m above sea level), Submontana Ombrophilous Dense Forest (50 to 500 m above sea level), and Montane Ombrophilous Dense Forest (500 to 1.200 m above sea level). In each altitude, all trees with a DBH ≥ 5,0 cm that fall inside 4 independent 1 hectare permanent plots, divided into a grid of 10 x 10 meter parcels, are being considered. The site extends from 23°15' S a 23° 40 S to 44° 40’ a 45° 40’ W. within areas of the Nucleus Caraguatatuba, Cunha, Picinguaba and Santa Virginia from the Serra do Mar State Park/PESM. The database on composition and structure of the forest will allow a choice of species for more detailed studies on reproduction biology; seed anatomy and reserves; germination; photosynthesis and water use efficiency; nitrogen assimilation, transport and metabolism; plant populations structure and dynamics; techniques; genetic structure of plant populations using molecular markers; determination of forest age by DBH classes and using 14C; determination of annual average growth rates of key species; and phenology. Multivariate analyses has been used to check for functional groups, or groups of species that share a common behavior and ecology. The comparison of different groups along the altitudinal gradient will allow investigation of the effect of altitude in the functioning of these groups. Simultaneously, the inputs of nitrogen through precipitation, biological fixation, and soil mineralization and nitrification are being determined, along with key parameters of N losses through denitrification and export by streams, allowing a preliminary nitrogen mass balance along the altitudinal gradient. Water and carbon balance of the forest will be estimated along with the seasonal variation of this balance through use of micrometeorological towers and Eddy-covariance technique. The photosynthesis/respiration balance of the ecosystem will be used to determine the role of the forest as a sink or source of carbon to the atmosphere. Our final goal is to integrate the results of all activities listed above, scaling-up from individual trees, to families, to functional groups, and finally to phytophysiognomies, allowing us to investigate in detail the structure and the functioning of the forest.