Total nitrogen and pH are key variables for functional structure of zooplanktonic communities in an agropastoral landscape

Author(s)

dos Santos, Natan Guilherme ; dos Santos, Eduardo Fernando ; Morari, Pedro Henrique Ribeiro ; Chiarelli, Laura Jardim ; Castilho-Noll, Maria Stela Maioli

• Document type: Journal article
• Source: Science of The Total Environment; v. 891, p. 8-pg., 2023-05-31.

Abstract

Changes in land use are one of the main impacts on aquatic ecosystems. The conversion of natural areas into agropastoral, such as pasture or monocultures, can affect the limnological characteristics of the water that in turn in-fluence the structure of aquatic communities. But the impact is still unclear, particularly on zooplankton communities. The objective of this study was to evaluate the effect of water parameters from eight reservoirs inserted in an agropastoral landscape on the functional structure of zooplankton. The functional characterization of the zooplankton community was based on four traits: body size, feeding type, habitat type, and trophic group. Functional diversity in-dices (FRic FEve and FDiv) were estimated and modeled water parameters, using generalized additive mixed models (GAAM). The water parameters investigated were total nitrogen (TN) and total phosphorus (TP), dissolved oxygen (OD), temperature and pH. Moreover, we used RDA to analyze the influence of these environmental variables on the sharing of traits among the sample sites. FRic was high in the reservoirs with low TN concentration and low pH values. FEve was also high in low pH and high TP concentration. FDiv was high with unsharp increases of pH and high concentrations of TN and DO. Our analyses showed pH as a key variable for functional diversity, since it was re-lated to the variation in all indices. Data also pointed out changes in diversity functional with small pH changes. The big and medium size, raptorial-cop and filtration-clad functional traits were positively associated with high concentra-tions of TN and alkaline pH. The small size and filtration-rot were negatively associated with high concentrations of TN and alkaline pH. Density of filtration-rot was lower in pasture landscapes. In conclusion, our study indicated that pH and TN are key variables for the functional structure of zooplanktonic communities in an agropastoral landscape. (AU)

• FAPESP's process: 04/04820-3 - Fauna and flora from forest fragments in the northwest region of São Paulo State: the basis to biodiversity conservational studies
• Grantee: Orlando Necchi Junior
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants
• FAPESP's process: 19/24576-5 - Effect of predation by planktivorous fish and macroinvertebrates on zooplankton functional diversity in subtropical shallow lakes
• Grantee: Pedro Henrique Ribeiro Morari
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 20/06632-2 - Fauna of the Neotropical Thynninae: distribution and new morphological and molecular data for the taxonomy of the group
• Grantee: Eduardo Fernando dos Santos
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 22/05412-4 - Effects of eutrophication and different substrates on the taxonomic and functional diversity of zooplankton in an integrated multitrophic aquaculture system
• Grantee: Laura Jardim Chiarelli
• Support Opportunities: Scholarships in Brazil - Scientific Initiation