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Revista de Biología Tropical, ISSN: 2215-2075 Vol. 69(2): 743-754, April-June 2021 (Published Jun. 21, 2021)
knowledge about wealth and diversity still
does not correspond to the coastal territorial
extension of the region. What makes broader
analysis impossible due to the particulari-
ties in various aspects of its biodiversity and
conservation status.
Considering, in particular the Maranhão
coastline, the knowledge about restinga vegeta-
tion is still restricted to a few floristic studies
(Cabral-Freire & Monteiro, 1993; Serra, Lima,
& Almeida Jr., 2016; Silva, Araujo, & Almeida
Jr., 2016a; Amorim, Amorim, & Almeida Jr.,
2016a; Lima & Almeida Jr., 2018) and phyto-
sociological records (Araujo, Silva, & Almeida
Jr., 2016; Amorim, Santos-Filho, & Almeida
Jr., 2016b; Machado & Almeida Jr., 2019;
Almeida Jr., Correia, & Santos-Filho, 2020).
These studies represent only a small part of the
coast in Maranhão, which is in turn in a large
transition area between vegetation in the Ama-
zon and Cerrado domain (Silva et al., 2016b).
Knowing that restingas can serve as a spe-
cies corridor in ecotonal environments, studies
covering the entire length of the Maranhão
coast are necessary to understand the diversity
and distribution of plant species present in the
restingas (Castro, Moro, & Menezes, 2012;
Serra, Lima, & Almeida Jr., 2016).
One of the ways to obtain information
about plant species for conservation is related
to knowledge of the structure of the plant
community (Nadkarni, Mcintosh, & Cushing,
2008). Thus, height and diameter measure-
ments could provide data on the plant com-
munity or be used for the analysis of one or
more species of interest in the succession
processes. The existence of different strata in
the plant community enables greater diver-
sity of micro-habitats, which can increase the
diversity of species and ecological interactions
(Souza, Souza, Gama, & Leite, 2003). There-
fore, vertical stratification could contribute as
an indicator of environmental sustainability
of a forest, influencing wealth, diversity, and
biomass production (Souza et al., 2003) among
other factors.
Therefore, evaluation of conditions regard-
ing the dynamics of the forest can generate
subsidies for future forest management actions
based on indications about the populations
in the development of the plant community
(Siminski, Mantovani, dos Reis & Fantini,
2004). Considering the need for data related
to the structure of the woody vegetation of
the restingas in Maranhão (Serra et al., 2016;
Machado & Almeida Jr., 2019; Almeida Jr. et
al., 2020), the current study aims to character-
ize the structure of woody vegetation, analyze
the diametric and hypsometric distribution of
species of greatest ecological importance, and
indicate the level of succession to support
future research on recovery and or management
of coastal areas.
MATERIALS AND METHODS
Study area: The collections were carried
out in a restinga in the Eastern part of Maranhão
Island (02º38’47.85’’ S & 44º09’05.76’’ W), on
the Sítio Aguahy. The area is owned by Com-
panhia Farmacêutica Quercegen Agronegócios
I Ltda., in the municipality of São José de Rib-
amar, Maranhão state (Fig. 1).
The Sítio Aguahy has an area of 400 ha
consisting of a transition between fragments
of regenerating Amazon forest, mangrove, and
restinga (Serra et al., 2016; Marinho, Muniz,
& Azevedo, 2018). The fragment denominated
restinga occupies an area of approximately 50
ha, consisting of vegetation from herbaceous
to arboreal stratum, presenting physiognomies
of floodable fields, non-floodable shrubby,
and non-floodable forest (Serra et al., 2016)
(Fig. 2). The climate of the region, according
to the classification of Köppen (1948), is of the
Aw type, having two distinct seasons: a rainy
season that extends from January to June and
a dry season that begins in July and extends
until December. The average rainfall index of
Maranhão Island is approximately 2 000 mm/
year and the average temperatures through-
out the year vary between 25.5 and 28.6 °C
(INMET, 2016).
Vegetation sampling: Phytosociological
sampling was carried out in 2015 and followed