Aquatic macroinvertebrates community alteration in headwater streams caused by land use changes in the semideciduous forest of the east-central region of São Paulo state

Author(s)

Fernanda Gaudio Augusto

• Document type: Doctoral Thesis
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Centro de Energia Nuclear na Agricultura (CENA/STB)
• Defense date: 2020-03-19

Examining board members

Luiz Antonio Martinelli; Ricardo Hideo Taniwaki

• Advisor: Luiz Antonio Martinelli; Marcos Callisto de Faria Pereira

Abstract

Land use changes leave streams unprotected and modify nutrient and flows sources between aquatic and terrestrial environments. The streams restoration, through the recovery of riparian forests, has been used to restored the structure and function of the ecosystem according to its original characteristics. The lack of restored areas monitoring generate a gap about the recovery of these environments. Aquatic macroinvertebrates are widely used organisms for monitoring river quality, based on the sensibility of some taxa regarding the environmental changes. The objective of this project was to evaluate the changes of aquatic macroinvertebrates community in streams with different land uses and land cover: agricultural, sugarcane and pastures, and restored forests between 4 and 100 years of restoration. The physicochemical parameters of the water were measured and the areas were characterized. Samples were collected in August 2017, in 13 streams. The macroinvertebrates were sampled by surber sample. These were separated and identified in morphotypes, quantified and classified into functional feeding groups. In addition, composition metrics and ecological indices were calculated for the macroinvertebrate community. The isotopic methodology was used to evaluate the influence of the stream microbasin on the macroinvertebrate diet. Thus, 13C and 15N values of macroinvertebrates and potential allochthonous or autochthonous food sources were measured. The influence of time restoration on the macroinvertebrates community and isotopic signature was evaluated by regression analysis. The ecological indexes were better (higher richness and diversity indices and lower abundance) in the pasture than sugarcane areas and the longer the time restoration. The C4 plants contribution to the MPSG was 60% in agricultural areas and 25% in forest areas. The C4 plants contribution to the macroinvertebrates was less than 15%. The C3 plants was the main components to the macroinvertebrates diets in 8 streams (2 sugarcane, 3 pasture and 3 restored streams). For the other streams, the main component was MPSG (1 forested and 2 sugarcane areas), autochthonous material (1 forested stream), or a mixture between C3 and MPSG (1 forested stream). The recovery of riparian forests is essential for the rehabilitation and maintenance of water bodies. Therefore, it is important the monitoring and study of these areas in order to better understanding the restoration process and its influence on aquatic environments. (AU)

• FAPESP's process: 16/07266-4 - Changes in the community of aquatic macroinvertebrates in headwater streams caused by changes in cover and land use of the semideciduous forest of the east-central region of São Paulo State
• Grantee: Fernanda Gaudio Augusto
• Support Opportunities: Scholarships in Brazil - Doctorate