615

ID:

The selection of sustainable tree species to be planted in disturbed or degraded areas determines the success or failure of reforestation projects. In general, the selection process is made by trial-and-error method, which takes time and can be unsuccess. Functional traits (morphological, physiological or phenological) affect the performance of trees and have been shown useful to screen sustainable species for restoration projects. However, this approach remains an important gap on the efforts of reforestation using Amazonia Forest species. In addition to the importance of using a large taxonomic diversity of species, the concept of multifunctionality (interspecific variation in the values of functional traits) is relevant to improve the resilience to environmental changes and productivity of plantations. The plant traits related to acquisition, processing, and conservation of resources can be considered ‘economic’ from a resource analysis perspective. At a leaf level, the resource economics traits are represented by the leaf economics spectrum. The leaf economics spectrum is related to the resource use by plants in a fast-slow continuum: species with a potential for quick returns (i.e., nutrient acquisition associated with fast growth and less durable structures) and species with a slow potential rate of return (i.e., nutrient conservation that results in a slow growth). Specifically, leaf traits representing resource use efficiency as photosynthetic use efficiency of the carbon (net photosynthesis/dark respiration ratio), nitrogen and phosphorus (net photosynthesis/nutrient concentration) explained the interspecific variation on the growth rates of Amazonian trees planted in disturbed areas. Species with high resource use efficiency had high growth rates. Chlorophyll a fluorescence parameter obtained from JIP-test congregate fast and non-invasive measurements and indicate the light use efficiency by species. We have found that Amazonian tree species with high nutrient use efficiency also exhibit efficient mechanisms to light trapping and processing. Thus, the best performance of Amazonian species growing in disturbed or degraded areas seems to be more related to species strategies in optimizing the site resources use for carbon assimilation. The design of plantations using species with different resource use strategies (low and high resource demand) is one of the most challenging factors in mixed-species plantations for protection and productive purposes. Therefore, understanding the resource use efficiency of species can help to identify those that can achieve greater establishment and that are more suitable for the composition of successful functional designs. These findings are important to improve reforestation efforts using native tree species to the Amazonia.

Keywords:

species selection
leaf functional traits
resource use efficiency
Amazonian tree species

Zilza Guimarães

Presentation within symposium:

S-32 Plant ecophysiology in a changing world: applications for forest management and restoration ecology

Using leaf functional traits as an approach to species screening in restoration projects in the Amazonia

-Review-