Occurrence of annual growth rings in Rhizophora mangle in a region with low climate seasonality.

Brunna T Souza,Gustavo C.D Estrada,Mário L.G Soares,Cátia H Callado

doi:10.1590/0001-3765201620150009

Brunna T Souza, Gustavo C.D Estrada + Show 2 more

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https://doi.org/10.1590/0001-3765201620150009

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Abstract

The formation of annual growth rings has been confirmed for several mangrove species in the last decade, among which is the Rhizophora mangle. However, the record of annual rings for this species was made in a region with high hydric seasonality, a widely recognized induction factor of annual rings in tropical species. In this sense, the present study aimed to verify the occurrence of annual growth rings in R. mangle in the mangroves of Guaratiba (Rio de Janeiro, Southeastern Brazil), a region with low hydric seasonality. For this purpose, the crossdating technique was applied in ten trees collected with known age (seven years). The growth rings are characterized by alternating layers of low vessel density (earlywood) and high vessel density (latewood). Multiple regression analysis indicated that growth rings width variation is driven by precipitation, water surplus, water deficit and water storage. Crossdating analysis confirmed the existence of annual growth rings in the R. mangle in Guaratiba. This discovery in a region with low hydric seasonality increases the dendrocronological potential of this species and suggests the importance of biological factors (eg. phenological behavior) as complementary inductors for the formation of growth rings in this species.

Highlights

The occurrence of annual growth rings in a woody plant is of great relevance, because it allows the use of the species in dendrochronological studies and their application in studies of climatology (Hughes 2002, Schongart et al 2004), archeology (Kuniholm 2002, Towner 2002), and ecology (Fritts and Swetnam 1989, Rozendal and Zuidema 2011), In the last fifteen years, the ocurrence of annual growth rings has been confirmed in someAn Acad Bras Cienc (2016) 88 (1 Suppl.)BRUNNA T
The occurrence of annual growth rings in a woody plant is of great relevance, because it allows the use of the species in dendrochronological studies and their application in studies of climatology (Hughes 2002, Schongart et al 2004), archeology (Kuniholm 2002, Towner 2002), and ecology (Fritts and Swetnam 1989, Rozendal and Zuidema 2011), Correspondence to: Gustavo Calderucio Duque Estrada E-mail: gustavo.estrada@uerj.br among others
The growth rings are composed by a sequence of a darker and thicker layer, characterized by low density vessels, followed by a clear and narrower layer, where the vessel density is higher (Fig. 2)

Summary

Introduction

The occurrence of annual growth rings in a woody plant is of great relevance, because it allows the use of the species in dendrochronological studies and their application in studies of climatology (Hughes 2002, Schongart et al 2004), archeology (Kuniholm 2002, Towner 2002), and ecology (Fritts and Swetnam 1989, Rozendal and Zuidema 2011), In the last fifteen years, the ocurrence of annual growth rings has been confirmed in someAn Acad Bras Cienc (2016) 88 (1 Suppl.)BRUNNA T. CALLADO mangrove species: Rhizophora mangle (Menezes et al 2003), R. mucronata (Verheyden et al 2004), R. apiculata (Yu et al 2004), Sonneratia apetala and Heritiera fomes (Chowdhury et al 2008), Laguncularia racemosa (Estrada et al 2008) and Luminitzera racemosa (Robert et al 2011). In most of these studies, the formation of annual rings is related to some degree of climate seasonality. In low seasonality conditions, the distinctness of the growth rings may be lower, making it more difficult to identify their limits (Estrada et al 2008), preventing them from being used in dendrochronological studies (Robert et al 2011)

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