Spatial and temporal variability in rocky shore assemblages at multiple scales can be driven by natural factors and anthropogenic disturbances, operating either separately to each other or in complex combinations. Using the shallow subtidal rocky habitat in Ilha Grande Bay (southeastern Brazil) as a model system, this study analyzed five natural and five anthropogenic variables as possible drivers of variability of cover in rocky shore assemblages, focusing on the following questions: (i) Which are the relevant horizontal scales of variation in assemblage structure?; (ii) Are patterns of horizontal variation consistent across a small depth range?; (iii) Are there significant relationships between spatial patterns of macroalgae and macroinvertebrates, and their potential natural and anthropogenic drivers? These issues were addressed through a hierarchical sampling strategy including five horizontal scales, namely quadrat (0.4–3 m), point (3–10 m), site (100–350 m), island (500–1000 m) and area (2000–6500 m), repeated at two depths (1–2 m and 3.5–4.5 m). The correlations of cover data of 21 groups of organisms and five natural and five anthropogenic variables were analyzed. Assemblages showed relevant variation among quadrats, points and sites, at both depths, while variation at the area scale was relevant only at 3.5–4.5 m depth, indicating that patterns of horizontal variation were not fully consistent between depths. Substrate rugosity, rocky shore extension, water movement, percentage of deforested land area and distance to urban center were the environmental variables that most explained spatial patterns of the assemblages. Our study highlights the potential role of such variables as drivers of variation in rocky subtidal assemblages at multiple spatial scales. For environmental protection programs, relevant scales of variation of target populations and assemblages need to be considered, to effectively capture their dynamics and underlying processes.

Natural and anthropogenic factors as possible drivers of variability in rocky shore assemblages at multiple spatial scales

Iacopo Bertocci
Secondo
;
2021-01-01

Abstract

Spatial and temporal variability in rocky shore assemblages at multiple scales can be driven by natural factors and anthropogenic disturbances, operating either separately to each other or in complex combinations. Using the shallow subtidal rocky habitat in Ilha Grande Bay (southeastern Brazil) as a model system, this study analyzed five natural and five anthropogenic variables as possible drivers of variability of cover in rocky shore assemblages, focusing on the following questions: (i) Which are the relevant horizontal scales of variation in assemblage structure?; (ii) Are patterns of horizontal variation consistent across a small depth range?; (iii) Are there significant relationships between spatial patterns of macroalgae and macroinvertebrates, and their potential natural and anthropogenic drivers? These issues were addressed through a hierarchical sampling strategy including five horizontal scales, namely quadrat (0.4–3 m), point (3–10 m), site (100–350 m), island (500–1000 m) and area (2000–6500 m), repeated at two depths (1–2 m and 3.5–4.5 m). The correlations of cover data of 21 groups of organisms and five natural and five anthropogenic variables were analyzed. Assemblages showed relevant variation among quadrats, points and sites, at both depths, while variation at the area scale was relevant only at 3.5–4.5 m depth, indicating that patterns of horizontal variation were not fully consistent between depths. Substrate rugosity, rocky shore extension, water movement, percentage of deforested land area and distance to urban center were the environmental variables that most explained spatial patterns of the assemblages. Our study highlights the potential role of such variables as drivers of variation in rocky subtidal assemblages at multiple spatial scales. For environmental protection programs, relevant scales of variation of target populations and assemblages need to be considered, to effectively capture their dynamics and underlying processes.
2021
Monclaro Carneiro, Ivan; Bertocci, Iacopo; Cesar de Paiva, Paulo; Teresa Menezes de Széchy, Maria
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/1109034
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 3
  • ???jsp.display-item.citation.isi??? 2
social impact