Soil Seed Bank as a Bioindicator to Identify Invasive Species

Abstract

This study aimed to characterize the soil seed bank in an area dominated by Leucaena leucocephala, here called “Povoamento de Leucaena” (PL) and an area of native forest in the Parque Estadual do Rio Doce (PERD), both of which are affected by the city of Ipatinga, MG. Thirty sample units (SU) with dimensions of 25.0 x 25.0 x 5.0 cm were installed in each of the study areas and the seed bank of the areas was collected and evaluated. The emerging seedlings were counted and identified; the evaluations were carried out weekly during the six-month period. The average density of germinated seeds was 716.2 seeds/m² in the PL and 86.4 seeds/m² in the PERD area. In addition, 39 species were identified in the PL area (41% exotic), while in the PERD area 32 species were identified (25% exotic). The exotic tree species that stood out in number of individuals were Muntingia calabura and L. leucocephala, representing 82.57% and 5.88%, respectively of the total individuals found. Therefore, both environments are under strong environmental pressure, requiring the control of existing exotic species, as well as enrichment actions with the planting of species of diversity to accelerate the restoration process in the PL area.

Relationship between soil seed bank and forest restoration techniques on areas around bauxite mining environment

“…The soil seed bank of both areas under restoration showed higher density of herbaceous individuals and richness of herbaceous species. This result corroborates studies carried out in areas undergoing secondary succession in the tropical forest (Miranda-Neto 2014b;Silva et al, 2019;Balestrin et al, 2019;Silva et al, 2021a;Martins et al, 2021;Silva et al, 2021b;Adjalla et al, 2022). These results suppose that the dominance of the herbaceous life form is related to the short life cycle of these species, high seed production and environmental conditions after disturbance, such as higher luminosity due to the lower plant coverage.…”

“…Thus, herbaceous plants are essential for the fast colonization a plant coverage recovery, which can stabilize soil aggregates and improve water retention and attenuate erosion processes during early successional stages (Martins et al, 2021). Furthermore, the absence of invasive exotic grasses can be a suitable indicator of the soil seed banks quality, since as the successional process advances, there will be an increase in shrub and tree species, and consequently higher canopy cover which can reduce the herbaceous species density in the soil seed bank (Balestrin et al, 2019;Silva et al, 2021b;Martins et al, 2021).…”

“…The soil seed banks composition is defined by local environmental conditions (i.e., luminosity, temperature, water availability) and by seed dispersal from aboveground vegetation (Martins et al, 2015;Shi et al, 2022). Therefore, the soil seed bank is essential for the maintenance of species diversity (i.e., species richness, species composition, dominance and evenness) during natural forest regeneration after disturbances (Balestrin et al, 2019;Silva et al, 2021b;Martins et al, 2021). Most of these studies on soil seed bank have focused mainly on the processes influencing the changes in community composition and species richness in disturbed areas compared to reference ecosystems (Miranda-Neto et al, 2016;Silva et al, 2019;Adjalla et al, 2022).…”

Restauração florestal em áreas atingidas pelo rejeito da barragem de Fundão, Minas Gerais, Brasil

“…A alta proporção de espécies compartilhadas (37,1 %) provavelmente se dá pela proximidade geográfica dos ambientes onde os bancos de sementes foram coletados e pelo histórico das áreas. Considerando o índice de Shannon, todos os bancos de sementes deste estudo apresentaram valores médios de diversidade, similares a outros estudos em Florestas Estacionais Semideciduais (BALESTRIN et al, 2019;MARTINS et al, 2021). Em relação à equabilidade, o ambiente próximo à pastagem apresentou menor valor, indicando maior uniformidade dos dados, ocasionada pelo domínio de indivíduos pertencentes a poucas espécies.…”

“…A geração de impactos ambientais negativos evidencia a necessidade de realização de ações de mitigação em um ambiente alterado. Diante disso, a restauração ecológica possui como objetivo principal retornar um ambiente degradado às condições anteriores ao distúrbio, recuperando sua biodiversidade e funções ecológicas e consequentemente aumentando as chances de restabelecimento do ecossistema (SER, 2004;GANN et al, 2019;DA ROSA & MARQUES, 2021;MARTINS et al, 2021;ROMANELLI et al, 2022). Assim, para alcançar os objetivos da restauração, deve-se utilizar técnicas que visem potencializar o aproveitamento da resiliência do próprio ambiente (MARTINS et al, 2012).…”