Population structure and effects by the invasive exotic indian-almond over autochthonous vegetation from a sandbank

João Paulo Bispo Santos,Juliano Ricardo Fabricante

doi:10.4013/nbc.2018.134.03

João Paulo Bispo Santos, Juliano Ricardo Fabricante

Open Access

https://doi.org/10.4013/nbc.2018.134.03

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Abstract

In the face of the severe effects caused by biological invasions, this study aimed at evaluating the population structure and impacts caused by the invasive exotic species T. catappa L. over native plant composition, richness and diversity. The study area is located at Atalaia Beach, Aracaju, Sergipe, Northeastern Brazil, and comprises sandbank sites. In order to evaluate the population structure of this invasive exotic species and its impacts on the biota, pertinent statistics were carried out. The results demonstrated that T. catappa shows density of 9,480 ind.ha-1, being 8,430 ind.ha-1 for non-adults and 1,050 ind.ha-1 for adults, and self-regenerating population. The average species richness for invaded (I) areas and non-invaded (NI) were 6.1 ± 2.42 and 9.7 ± 2.45, respectively. The average abundance of individuals in NI was 1,057.6 ± 432.85 and 184.9 ± 126.66 for I. The diversity and the equability were 2.38 and 0.66 in I and 2.86 and 0.75 in NI, respectively. Thus, T. catappa causes significant impacts on species composition and richness, abundance and autochthonous diversity. Keywords: biological invasion, ecology, environmental impacts.

Highlights

As a priority area for biodiversity conservation (Hotspot) due to the huge amount of endemic species that it shelters and the devastation of its habitat (Myers, 1988; Myers et al, 2000; Mittermeier et al, 2011), the Atlantic Forest has about 7,000 endemic plant species and is composed by a set of ecosystems, among them sandbank (Stehmann et al, 2009)
In the face of the severity effects caused by biological invasions and this subject information lack for Sergipe coast, this study aimed to evaluate the population structure and impacts caused by the invasive exotic species T. catappa over native plants composition, richness and diversity
At I, the abundance values for T. catappa were 94.8 ± 91.1, with 84.3 ± 93.12 being regenerating and 10.5 ± 8.51 adults

Summary

Introduction

As a priority area for biodiversity conservation (Hotspot) due to the huge amount of endemic species that it shelters and the devastation of its habitat (Myers, 1988; Myers et al, 2000; Mittermeier et al, 2011), the Atlantic Forest has about 7,000 endemic plant species and is composed by a set of ecosystems, among them sandbank (Stehmann et al, 2009). The sandbank is extremely important due to different functions it performs in the ecosystem, its vegetation is responsible for the substrate fixation, protecting it against erosive agent action, mostly wind, as well as supplying resources to the local fauna (Lamêgo, 1974; Assumpção and Nascimento, 2000; Scherer et al, 2005). It has a great vegetation richness with nearly 2,591 species (Lista de Espécies da Flora do Brasil, 2017), it has suffered intense environmental degradation caused by anthropogenic activities (Holzer et al, 2004, Santos-Filho, 2009). The continuous degradation condition that sandbank sites are exposed to, provides biota decrease and its structural components disorder (Holzer et al, 2004) favoring processes of biological invasion (BI) (Almeida-Júnior et al, 2007; Santos-Filho, 2009; Cantarelli et al, 2012; Queiroz et al, 2012), since disturbed environments, with low diversity and richness, tend to be more susceptible to them

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